Vehicle notification system

Abstract

A vehicle notification system 1 includes: a pedestrian detection unit B121a that detects an object to be monitored that is movable in a sidewalk at the intersection CS or in a predetermined area around the intersection CS; a first notification issuing unit B118a and a second notification issuing unit B119a that perform notification issuance in a first mode to avoid collision between the right turning vehicle VA and the straight traveling vehicle VB; and a third notification issuing unit B122a that performs notification issuance in a second mode for the right turning vehicle VA to avoid collision between the right turning vehicle VA and the object to be monitored that has been detected by the pedestrian detection unit B121a. The notification issuance in the first mode and the notification issuance in the second mode are performed with mutually different sounds in the right turning vehicle VA.

Description

BACKGROUND OF THE INVENTIONField of the Invention

[0001] Embodiments of the present invention relate to a vehicle notification system.Description of the Related Art

[0002] For the purpose of assisting driving in situations where right turn is made at intersections on left-hand traffic roads, there is a technology of recognizing operation statuses of other traffic participants including oncoming vehicles moving straight ahead toward intersections in opposite lanes and providing an instruction for a right turn timing that allows a driver to avoid collisions against the oncoming vehicles to the driver.

[0003] Here, detection of traffic participants is typically performed by in-vehicle sensors such as cameras or radars.

[0004] [Patent Document 1] JP 2009-265832 A

[0005] However, it is difficult for in-vehicle sensors to detect traffic participants who are present at blind angles such as behind obstacles.

[0006] Specifically, in a case where there is another vehicle traveling side by side with an oncoming vehicle in the same lane, or in a case where another vehicle is stopping to wait for turning right in front of the oncoming vehicle, the vehicle may become an obstacle, and the oncoming vehicle may be present at a blind angle of the vehicle, which may make it difficult to detect the oncoming vehicle depending on an in-vehicle sensor equipped in the right turning vehicle.

[0007] In a case where the vehicle that may become an obstacle is a large vehicle, the blind angle becomes wider, which makes it more difficult to detect the oncoming vehicle.

[0008] In driving assistance, notifications are implemented to inform drivers of occurrence of various events. Types of notifications for the drivers include, for example, auditory notifications by sound and / or voice using speakers, visual notifications through display of text and / or illustration on displays, and tactile notifications by vibrations of steering wheels. It is desirable that notifications do not hinder driving of a driver and make it easy for the driver to know a target to which attention is to be paid.SUMMARY OF THE INVENTION

[0009] Thus, an object of the present invention is to provide a vehicle notification system capable of providing a notification that does not hinder driving of a driver and makes it easy for the driver to know a target to which attention is to be paid and contributing to a further improvement in traffic safety.

[0010] To solve the above-mentioned problem, a vehicle notification system according to one aspect of the present invention performs notification issuance at least with sounds for traffic participants including a first vehicle that is present in a traveling lane leading to an intersection to turn right or left at the intersection and a second vehicle that travels in a straight traveling direction toward the intersection in a lane opposite to the traveling lane. The vehicle notification system includes: a monitored object detection unit that detects an object to be monitored that is movable in a sidewalk at the intersection or in a predetermined area around the intersection; a first notification issuing unit that performs notification issuance in a first mode to avoid collision between the first vehicle and the second vehicle; and a second notification issuing unit that performs notification issuance in a second mode for the first vehicle to avoid collision between the frist vehicle and the object to be monitored that has been detected by the monitored object detection unit. The notification issuance in the first mode and the notification issuance in the second mode are performed with mutually different sounds in the first vehicle.EFFECTS OF THE INVENTION

[0011] According to one aspect of the present invention, it is possible to provide a vehicle notification system capable of providing a notification that does not hinder driving of a driver and makes it easy for the driver to know a target to which attention is to be paid and contributing to a further improvement in traffic safety.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 is a schematic diagram illustrating an overall configuration of a vehicle notification system according to an embodiment of the present embodiment; Fig. 2 is a schematic diagram illustrating an internal configuration of a controller included in a right turning vehicle; Fig. 3 is a schematic diagram illustrating an internal configuration of a controller included in a straight traveling vehicle; Fig. 4 is a flowchart illustrating an overall flow of notification control; Fig. 5 is a flowchart illustrating content of early notification issuance processing; Fig. 6 is a flowchart illustrating content of the early notification issuance processing (information presentation processing); Fig. 7 is a flowchart illustrating content of the early notification issuance processing (alarm processing); Fig. 8 is a flowchart illustrating content of normal notification issuance processing; Fig. 9 is a flowchart illustrating content of the normal notification issuance processing (information presentation processing); Fig. 10 is a flowchart illustrating content of the normal notification issuance processing (alarm processing); Fig. 11 is an explanatory diagram illustrating a method of calculating an information presentation distance and an alarm distance; Fig. 12 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a target of a notification; Fig. 13 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at a notification issuance timing for information presentation; Fig. 14 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at a notification issuance timing for alarm; Fig. 15 is a schematic diagram illustrating the configuration of determination areas when the intersection area is expanded; Fig. 16 is a schematic diagram illustrating the configuration of determination areas when the predicted collision area is reduced; Fig. 17 is a schematic diagram showing the timing of detection of a subject of surveillance and the corresponding notification issuance after a right turning vehicle has entered the intersection area; Fig. 18 a schematic diagram showing the timing of detection of a subject of surveillance and the corresponding notification issuance before a right turning vehicle reaches the intersection area; Fig. 19 is a flowchart illustrating an overall flow of notification control according to another embodiment of the present invention; Fig. 20 is a schematic diagram showing a situation in which a straight traveling vehicle passes through the intersection before a right turning vehicle enters the intersection; Fig. 21 is a schematic diagram showing a situation in which a right turning vehicle passes through the intersection before a straight traveling vehicle reaches the notification issuance position; Fig. 22 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the right turning vehicle; Fig. 23 is a schematic diagram illustrating an example of the notification issuance in the second mode through display in the notification control performed in the right turning vehicle; Fig. 24 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the straight traveling vehicle; and Fig. 25 is a schematic diagram illustrating an example of the notification issuance in the fourth mode through display in notification control performed in the right turning vehicle. DETAILED DESCRIPTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same reference signs are given to identical or equivalent components in each figure.(Overall Configuration of Vehicle Notification System)

[0014] Fig. 1 is a schematic diagram illustrating a configuration of a vehicle notification system (hereinafter, simply referred to as a "notification system" in some cases) 1 according to an embodiment of the present invention.

[0015] In the present embodiment, a traffic situation where a vehicle (hereinafter, referred to as a "right turning vehicle") VA traveling toward an intersection on a left-hand traffic road and another vehicle (hereinafter, referred to as a "straight traveling vehicle") VB traveling in a straight direction toward the intersection in a lane (hereinafter, referred to as an "opposite lane" in some cases) opposite to a lane (hereinafter, referred to as a "traveling lane" in some cases) in which the right turning vehicle VA is traveling are present is assumed. The notification system 1 can be applied not only to left-hand traffic roads but also to right-hand traffic roads. In a case of right-hand traffic, a traffic situation where a left turning vehicle traveling toward an intersection and a straight traveling vehicle traveling toward the intersection in an opposite lane are present is a target. In other words, the notification system 1 can be applied to traffic situations where a right or left turning vehicle (hereinafter, referred to as a "right or left turning vehicle" or a "non-straight traveling vehicle") in a traveling lane and a straight traveling vehicle in an opposite lane are present together. In a case of left-hand traffic, the right turning vehicle is a vehicle turning right at the intersection and should not hinder the straight traveling vehicle traveling in the opposite lane from passing the intersection.

[0016] The notification system 1 includes, as main elements related to the present embodiment, auxiliary devices such as vehicle sensors 111 to 113, communication devices 121 and 122, and a human machine interface (HMI) device 131 in addition to a controller 101.

[0017] In the present embodiment, various elements including the controller 101 are provided in each of the right turning vehicle VA and the straight traveling vehicle VB. A controller 101a included in the right turning vehicle VA and a controller 101b included in the straight traveling vehicle VB configure one virtual controller constituting the notification system 1 through mutual cooperation. It is a matter of course that the notification system 1 can be configured as an in-vehicle system for the right turning vehicle VA by the controller 101a included in the right turning vehicle VA and the auxiliary devices thereof and can also be configured as an in-vehicle system for the straight traveling vehicle VB by the controller 101b included in the straight traveling vehicle VB and the auxiliary devices thereof.

[0018] In the following description, vehicle-to-vehicle communication is performed between the right turning vehicle VA and the straight traveling vehicle VB to allow vehicle information related to the right turning vehicle VA to be shared between the right turning vehicle VA and the straight traveling vehicle VB and allow vehicle information related to the straight traveling vehicle VB to be shared between both the vehicles VA and VB. In the present embodiment, the vehicle information to be communicated or shared between the right turning vehicle VA and the straight traveling vehicle VB includes current positions Pa and Pb, vehicle speeds VSPa and VSPb, operating statuses of right turn signals (that is, outputs of right turn signal switches), and lane IDs of the vehicles VA and VB. Furthermore, the vehicle information may include a type of each of the vehicles VA and VB. The communication between the right turning vehicle VA and the straight traveling vehicle VB is not limited to direct communication via vehicle-to-vehicle communication and may also be performed indirectly through roadside equipment installed at roadsides, servers disposed remotely, communication devices included in vehicles other than the right turning vehicle VA and the straight traveling vehicle VB. Hereinafter, vehicle information related to the right turning vehicle VA may be referred to as right turning vehicle information, and vehicle information related to the straight traveling vehicle VB may be referred to as straight traveling vehicle information. In the present embodiment, the types of the vehicles VA and VB in the vehicle information to be communicated or shared between the right turning vehicle VA and the straight traveling vehicle VB means which of a two-wheeled vehicle or a four-wheeled vehicle each of the right turning vehicle VA and the straight traveling vehicle VB is. The two-wheeled vehicle refers to a motorcycle.

[0019] In the present embodiment, the right turning vehicle VA and the straight traveling vehicle VB constitute the notification system 1 with similar basic configurations. The right turning vehicle VA includes the controller 101a and also includes vehicle sensors 111a, 112a, and 113a, communication devices 121a and 122a, and an HMI device 131a. On the other hand, the straight traveling vehicle VB includes the controller 101b and also includes vehicle sensors 111b, 112b, and 113b, communication devices 121b and 122b, and an HMI device 131b.

[0020] The controllers 101a and 101b constitute a calculation unit of the notification system 1 and generate and output a command signal in accordance with results of calculation. The controllers 101a and 101b are configured of microcomputers including central processing units (CPUs), storage devices such as ROMs and RAMs, and input / output interfaces.

[0021] The vehicle sensors 111a to 113a and 111b to 113b constitute a detection unit of the notification system 1. The right turning vehicle VA includes a position sensor 111a, a vehicle speed sensor 112a, and a right turn signal switch 113a as the accompanying vehicle sensors, while the straight traveling vehicle VB includes a position sensor 111b, a vehicle speed sensor 112b, and a right turn signal switch 113b as the accompanying vehicle sensors.

[0022] The position sensor 111a detects the current position Pa of the right turning vehicle VA, and the position sensor 111b detects the current position Pb of the straight traveling vehicle VB. Both the position sensors 111a and 111b can be configured of global navigation satellite system (GNSS) receivers and detect the current positions of the target vehicles VA and VB with latitude and longitude coordinates Pa (Pai, Paj) and Pb (Pbi, Pbj).

[0023] The vehicle speed sensor 112a detects the traveling speed (hereinafter, referred to as a "vehicle speed") VSPa of the right turning vehicle VA, while the vehicle speed sensor 112b detects the vehicle speed VSPb of the straight traveling vehicle VB. The vehicle speed sensors 112a and 112b can perform the detection by detecting wheel speeds (for example, rotation speeds of driven wheels) of the target vehicles VA and VB and converting the wheel speeds into traveling distances per unit time using tire dynamic radii or the like.

[0024] The right turn signal switch 113a outputs an on signal when a right direction indicator (hereinafter, referred to as a "right turn signal") included in the right turning vehicle VA is activated, and the right turn signal switch 113b outputs an on signal when the right turn signal included in the straight traveling vehicle VB is activated. The operations of the right turn signal switches 113a and 113b indicate that the target vehicles VA and VB intend to turn right on the road or change lanes.

[0025] Detection signals from the position sensor 111a, the vehicle speed sensor 112a, and the right turn signal switch 113a are output to the controller 101a, while detection signals from the position sensor 111b, the vehicle speed sensor 112b, and the right turn signal switch 113b are output to the controller 101b.

[0026] The HMI devices 131a and 131b constitute an output unit of the notification system 1. The HMI device 131a receives a command signal from the controller 101a and provides a notification related to a traffic situation to a driver of the right turning vehicle VA. The HMI device 131b receives a command signal from the controller 101b and provides a notification related to the traffic situation to a driver of the straight traveling vehicle VB.

[0027] Notifications by the HMI devices 131a and 131b are at least auditorily performed. The notifications by the HMI devices 131a and 131b are not limited thereto and may include, in addition to auditory notifications, visual notifications. In other words, the notification system 1 can issue notifications through sound via the HMI devices 131a and 131b, and can also issue notifications both through sound and through display. The HMI devices 131a and 131b are disposed at locations that allow the drivers to easily view the HMI devices 131a and 131b, such as on dashboards in the vehicles. Note that in the present embodiment, the notification through sound includes notifications through alert sounds such as buzzer sounds, beeps, and electronic sounds, or notifications through voice guidance based on recorded human voices or on machine-generated voices.

[0028] Moreover, the HMI devices 131a and 131b include, for example, speakers 141a and 141b as audio output units, and displays 143a and 143b as display units. The speakers 141a and 141b convey content of notifications to the driver by sound. This enables auditory notifications. Moreover, the displays 143a and 143b display content of notifications to the driver at least by illustration. The content of the notifications on the displays 143a and 143b may include texts. This enables visual notifications. Additionally, the HMI devices 131a and 131b further include touch panels, switches, and keys, which are not illustrated in the drawings.

[0029] The right turning vehicle VA includes a transmitter 121a and a receiver 122a, while the straight traveling vehicle VB includes a transmitter 121b and a receiver 122b. The transmitter 121a and the receiver 122a included in the right turning vehicle VA constitute a vehicle-to-vehicle communication device of the right turning vehicle VA, while the transmitter 121b and the receiver 122b included in the straight traveling vehicle VB constitute a vehicle-to-vehicle communication device of the straight traveling vehicle VB. The right turning vehicle VA and the straight traveling vehicle VB can perform wireless communication via the mutual vehicle-to-vehicle communication devices.

[0030] As mentioned earlier, the communication between the right turning vehicle VA and the straight traveling vehicle VB is not limited to direct communication between the right turning vehicle VA and the straight traveling vehicle VB and may also be indirect communication via roadside equipment, remote servers, other vehicles, or the like.

[0031] Moreover, when the right turning vehicle VA passes the intersection, the right turning vehicle VA monitors the intersection or a predetermined area around the intersection, and in a case where a pedestrian or another subject of surveillance to be monitored is detected in the predetermined area, notification issuance to promote the right turning vehicle (specifically, the driver thereof) to pay attention to the subject of surveillance is performs at least through sound via the HMI device 131a. The driver of the right turning vehicle VA can pay attention to the subject of surveillance by the activation of the HMI device 131a and recognize presence of the subject of surveillance in a case where the subject of surveillance is present in the predetermined area.

[0032] In the present embodiment, the subject of surveillance to be monitored refers to an individual or a person who is legally permitted to move or travel along a sidewalk, such as a pedestrian or a mobility scooter passenger. Also, an area on the side further forward than the center of the intersection (hereinafter, referred to as an "intersection center") with respect to the traveling direction of the right turning vehicle VA passing the intersection, that is an area including a crosswalk provided on the road after the right turn (hereinafter, referred to as a "crosswalk after the right turn" in some cases) is set as an "intersection surrounding area", and the intersection surrounding area is regarded as a target to be monitored.

[0033] The controller 101a of the right turning vehicle VA is capable of communicating with a mobile communication device 201 held by the subject of surveillance. The mobile communication device 201 in a case where the subject of surveillance is a pedestrian is, for example, a mobile terminal such as a smartphone, and the mobile communication device 201 in a case where the subject of surveillance is a mobility scooter passenger is, for example, an in-vehicle communication device included in the mobility scooter. The controller 101a detects the position of the subject of surveillance on the basis of a signal transmitted from the mobile communication device 201 and detects the subject of surveillance in the intersection surrounding area by the position of the subject of surveillance being located in the intersection surrounding area.

[0034] The communication between the controller 101a and the mobile communication device 201 may be unidirectional communication from the mobile communication device 201 to the controller 101a or may be bidirectional communication therebetween. In a case where the communication is bidirectional, it is possible to notify the subject of surveillance of the presence of the right turning vehicle VA that has detected the subject of surveillance and promote the subject of surveillance to pay attention to the right turning vehicle VA. For example, voice guidance may be performed via a smartphone, which is the mobile communication device 201, to let the subject of surveillance know the presence and approach of the right turning vehicle VA.

[0035] Furthermore, the communication between the controller 101a and the mobile communication device 201 may be direct or indirect. The controller 101a and the mobile communication device 201 can communicate unidirectionally or bidirectionally via a traffic signal SG (specifically, a communication terminal included in the signal SG) installed by the crosswalk, for example.

[0036] The detection of the subject of surveillance can be performed not only by the mobile communication device 201 but also by a surveillance camera installed to be able to monitor the intersection surrounding area. Specifically, an image acquired by the surveillance camera is analyzed, and a signal indicating that the subject of surveillance has been detected is sent from the surveillance camera to the controller 101a in a case where the subject of surveillance is detected in the intersection surrounding area.

[0037] Fig. 12 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a notification target according to the present embodiment.

[0038] In the present embodiment, a traffic situation in which the right turning vehicle VA and the straight traveling vehicle VB face each other with an intersection CS interposed therebetween is assumed. The intersection (a cross intersection in the present embodiment) CS is present on a road R with two lanes on each side including right turn lanes L11 and L21 and straight lanes L12 and L22. The right turning vehicle VA is present in the right turn lane L11 on one side and is approaching the intersection CS, while the straight traveling vehicle VB is present in the straight lane L22 on the other side and is traveling at a position separated from the intersection CS in a straight direction toward the intersection CS. Here, the right turn lane L11 corresponds to the traveling lane of the right turning vehicle VA, and the right turn lane L21 and the straight lane L22 correspond to lanes opposite to the right turning vehicle VA. The right turn lane L21 and the straight lane L22 as the opposite lanes may be referred to as an "opposite right turn lane" and an "opposite straight lane" below.

[0039] On the road R, a crosswalk PC1 is provided in front of the intersection CS for the right turn lane L11 and the straight traveling lane L12, and a crosswalk PC2 is provided in front of the intersection CS for the opposite right turn lane L21 and the opposite straight traveling lane L22. Furthermore, a crosswalk (that is, a crosswalk after the right turn) PC3 is provided on the road after the right turn of the right turning vehicle VA, and a crosswalk PC4 is provided on the road on the side opposite to the road after the right turn with the intersection CS interposed therebetween. A stop line SL1 is provided at front ends of the right turn lane L11 and the straight traveling lane L12 near the intersection CS, and a stop line SL2 is provided at front ends of the opposite right turn lane L21 and the opposite straight traveling lane L22 near the intersection CS. Similarly, stop lines SL3 and SL4 are provided in front of the crosswalks PC3 and PC4, respectively, on the roads leading to the intersection CS other than the above roads in a state where the intersection CS is seen in front.

[0040] In the present embodiment, the area including the crosswalk PC3 after the right turn and its surroundings is set as an "intersection surrounding area" AAC. Fig. 12 schematically illustrates the intersection surrounding area AAC by a dashed line frame. The intersection surrounding area AAC includes, in the "intersection surroundings", regions before and after the crosswalk PC3 in a length direction and regions on both sides of the crosswalk PC3 in the direction perpendicular to the length direction on the assumption that a moving direction when the crosswalk PC3 is crossed is the length direction of the crosswalk PC3. In other words, in the present embodiment, the intersection surrounding area AAC is an area obtained by expanding the crosswalk PC3 in the four directions, namely the front, rear, left, and right directions. The intersection surrounding area AAC can be appropriately set as an area where a subject of surveillance to be monitored such as a pedestrian may be present and can be set in an appropriate shape such as an ellipse or an oval, as well as the rectangle illustrated in Fig. 12.

[0041] In addition to the right turning vehicle VA and the straight traveling vehicle VB, a vehicle (hereinafter, referred to as a "waiting vehicle") VC stopping to wait for turning right is present before a stop line SL2 in front of the straight traveling vehicle VB in the opposite right turn lane L21. In the illustrated traffic situation, the waiting vehicle VC is a visual obstacle blocking a part of a view from the right turning vehicle VA and blocking a part of a view from the straight traveling vehicle VB. In this situation, it is difficult to visually recognize the straight traveling vehicle VB from the right turning vehicle VA due to the straight traveling vehicle VB being present at a blind angle of the waiting vehicle VC seen from the right turning vehicle VA, and it is difficult to visually recognize the right turning vehicle VA from the straight traveling vehicle VB due to the right turning vehicle VA being present at a blind angle of the waiting vehicle VC seen from the straight traveling vehicle VB.

[0042] In such a situation, the notification system 1 monitors a relative positional relationship between the right turning vehicle VA and the straight traveling vehicle VB after the right turning vehicle VA displays its intention to turn right. Then, the notification system 1 issues a notification in accordance with a degree of urgency of circumstances related to collision between the right turning vehicle VA and the straight traveling vehicle VB at an appropriate timing after the right turning vehicle VA approaches the intersection CS and before the right turning vehicle VA passes the intersection CS. Note that in the present embodiment, the notification system 1 ends the notification issuance at a timing at which the right turning vehicle VA has passed the intersection CS.

[0043] In conjunction with this, the notification system 1 performs notification issuance to promote the right turning vehicle VA to pay attention to the subject of surveillance in a case where the subject of surveillance, for example, a pedestrian crossing the crosswalk PC3 is detected in the intersection surrounding area AAC. In the following description, a case where a pedestrian is assumed to be a subject of surveillance will be exemplified.(Internal Configuration of Controller)

[0044] Fig. 2 is a schematic diagram illustrating an internal configuration of the controller 101a included in the right turning vehicle VA, and Fig. 3 is a schematic diagram illustrating an internal configuration of the controller 101b included in the straight traveling vehicle VB. The internal configuration of each of the controllers 101a and 101b will be described in turn on the basis of Figs. 2 and 3 and with reference to Fig. 12 as needed.

[0045] As illustrated in Fig. 2, the controller 101a includes a host vehicle position detection unit B111a, an other vehicle position detection unit B112a, a road map storage unit B113a, a right turn intention detection unit B114a, a driving state detection unit B115a, a first notification issuance timing setting unit B116a, a second notification issuance timing setting unit B117a, a first notification issuing unit B118a, a second notification issuing unit B119a, a determination area setting unit B120a, a pedestrian detection unit B121a and a third notification issuing unit B122a. A function of each of these units B111a to B122a is realized in a software manner by the central processing unit included in the controller 101a reading a computer program stored in the storage device and operating in accordance with instructions of the program.

[0046] Note that data held by each of the components B111a to B122a and results of processing performed by each of the components B111a to B122a can be mutually referenced among the components B111a to B122a regardless of the presence or absence of arrows indicating a data flow inside the controller 101a in Fig. 2. The data held by each of the components B111a to B122a includes detection signals from the vehicle sensors 111a, 112a, and 113a output to the controller 101a, and vehicle information acquired from the straight traveling vehicle VB via the receiver 122a. These premises in the controller 101a are also applicable to the controller 101b of the straight traveling vehicle VB.

[0047] The host vehicle position detection unit B111a detects the current position Pa of the right turning vehicle VA, which is a host vehicle. The detection of the current position Pa performed by the host vehicle position detection unit B111a is based on an output signal from the position sensor 111a included in the right turning vehicle VA.

[0048] The other vehicle position detection unit B112a detects the current position Pb of the straight traveling vehicle VB, which is another vehicle. The detection of the current positions Pb performed by the other vehicle position detection unit B112a is performed by reading position information indicating the current position Pb from vehicle information acquired from the straight traveling vehicle VB via the receiver 122a included in the right turning vehicle VA.

[0049] The road map storage unit B113a stores a road map. In the present embodiment, the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB are coordinates of latitudes and longitudes indicating these positions Pa and Pb. The road map storage unit B113a extracts a map of a range or a section including the intersection CS and its surroundings in the road map and specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map. In the road map, identifiers (hereinafter, referred to as "link IDs") corresponding to lanes leading to the intersection CS, such as the right turn lanes L11 and L21 and the straight lanes L12 and L22, are assigned and are stored in association with the corresponding lanes L11, L21, L12 and L22. It is possible to distinguish the lane in which a target vehicle is present or is traveling by specifying the position on the road map. Furthermore, in the road map, the intersection surrounding area AAC is defined by specifying the coordinates on the road map corresponding to the locations included within it.

[0050] The right turn intention detection unit B114a detects that the right turning vehicle VA has a right turn intention. The right turn intention detection by the right turn intention detection unit B114a can be performed with an output signal from the right turn signal switch 113a included in the right turning vehicle VA, and in a case where the right turn lane L11 is a lane only for right turn, the detection can also be performed by reading the link ID associated with the lane where the vehicle is traveling from the road map and detecting that the right turning vehicle VA is present in the right turn lane L11.

[0051] The driving state detection unit B115a detects the vehicle speed VSPb of the straight traveling vehicle VB. The driving state detection unit B115a detects the vehicle speed VSPb by reading vehicle speed information indicating the vehicle speed VSPb from the vehicle information acquired from the straight traveling vehicle VB via the receiver 122a included in the right turning vehicle VA.

[0052] The first notification issuance timing setting unit B116a detects that the right turning vehicle VA is present at a predetermined position relative to the intersection CS, specifically, that the right turning vehicle VA is at a predetermined distance from the center position CTR (hereinafter, referred to as an "intersection center") of the intersection CS or at a position closer to the intersection center CTR than the predetermined distance after the right turn intention detection unit B114a detects the right turn intention, that is, after the right turning vehicle VA displays its right turn intention by entering the right turn lane L11 or by operating a right turn signal, on the basis of the current position Pa of the right turning vehicle VA on the road map. Then, the first notification issuance timing setting unit B116a sets the timing at which presence of the right turning vehicle VA at the predetermined position relative to the intersection CS is detected as a first notification issuance timing. The first notification issuance timing set by the first notification issuance timing setting unit B116a is the timing at which the right turning vehicle VA performs notification issuance for information presentation. The notification issuances performed at the first notification issuance timing and the second notification issuance timing described below, or notification issuances for information presentation and alarm that the controller 101a executes correspond to the "notification issuance in the first mode" directed at the right turning vehicle VA.

[0053] The second notification issuance timing setting unit B117a monitors a behavior of the right turning vehicle VA after the setting of the first notification issuance timing. The second notification issuance timing setting unit B117a regards a point at which a path TRa where the right turning vehicle VA travels when the right turning vehicle VA passes the intersection CS and a path TRb where the straight traveling vehicle VB travels when the straight traveling vehicle VB passes the intersection CS intersect as a "predicted collision point" CPP and detects that the right turning vehicle VA is traveling toward the predicted collision point CPP or has approached the predicted collision point CPP by a predetermined distance after the setting of the first notification issuance timing on the basis of the current position Pa of the right turning vehicle VA on the road map. Then, the second notification issuance timing setting unit B117a sets the timing at which any of these behaviors is detected in the right turning vehicle VA as a second notification issuance timing. The second notification issuance timing set by the second notification issuance timing setting unit B117a is a timing at which the right turning vehicle VA performs notification issuance for alarm.

[0054] Fig. 13 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at a timing when the right turning vehicle VA exceeds the stop line SL1 in the right turn lane L11 and enters the intersection CS. Fig. 13 illustrates only the right turn lane L11 and the straight lane L22 in the road R with two lanes on each side by simplifying the illustration of the road R (the same applies to Figs. 14, 15, 16, 17, 18, 20 and 21, which will be described later).

[0055] In the present embodiment, an intersection area ACS is set as a determination criterion to recognize the relative positional relationship between the right turning vehicle VA and the intersection CS. The setting of the intersection area ACS may be performed by the determination area setting unit B120a described later. The intersection area ACS is set to overlap a path TRa along which the right turning vehicle VA travels when passing the intersection CS, and the presence of the right turning vehicle VA at the predetermined relative position to the intersection area ACS is detected by arrival of the right turning vehicle VA at the intersection area ACS or entrance thereof into the intersection area ACS after displaying its right turn intention. The intersection area ACS is set as a circular area that has a predetermined radius φacs concentrically with the intersection center CTR. Figs. 13 to 18, 20 and 21illustrate the intersection area ACS by two-dotted chain lines, illustrate the traveling path TRa of the right turning vehicle VA by one-dotted chain lines, and illustrate a predicted collision area ACP and a traveling path TRb of the straight traveling vehicle VB, which will be described later, by dashed lines and one-dotted chain lines, respectively.

[0056] Fig. 14 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at a timing at which the right turning vehicle VA moves ahead inside the intersection CS and approaches the intersection center CTR after entering the intersection CS.

[0057] In the present embodiment, the predicted collision area ACP with the predicted collision point CPP included at its center is set as an area that is different from the intersection area ACS. The setting of the predicted collision area ACP may be performed by the determination area setting unit B120a similarly to the intersection area ACS. The traveling of the right turning vehicle VA toward the predicted collision point CPP in the intersection area ACS or presence of the right turning vehicle VA in the predicted collision area ACP is detected after entering the intersection area ACS. The predicted collision area ACP is set as a circular area that has a predetermined radius φacp and has a smaller area than the intersection area ACS.

[0058] The shape of the intersection area ACS is not limited to the circular shape and may be a shape (for example, a quadrangular shape having four corners at a corner cut) following a range in which the two intersecting roads overlap or may be a shape within a range surrounded by the stop lines SL1, SL2, SL3 and SL4 (Fig. 12) provided in the intersecting roads, respectively. The same applies to the predicted collision area ACP, and it is possible to set a shape other than the circular shape, such as a quadrangular shape (for example, a quadrangular shape having two sides that are parallel to a road boundary line defining the opposite straight lane L22).

[0059] The first notification issuing unit B118a outputs a command signal to issue a notification for information presentation to the HMI device 131a included in the host vehicle (that is, the right turning vehicle VA) under a condition that a first predetermined notification issuance condition defined in advance in regard to the position Pb of another vehicle, which is the straight traveling vehicle VB, is established at a first notification issuance timing that the first notification issuance timing setting unit B116a has set.

[0060] The first predetermined notification issuance condition is that the straight traveling vehicle VB is present at a first predetermined distance (hereinafter, referred to as an "information presentation distance") Dth1, which is relatively long, from the intersection CS or at a position closer to the intersection CS than the first predetermined distance Dth1. In the present embodiment, the distance from the outer edge of the predicted collision area ACP, specifically, an intersecting point between the traveling path TRb of the straight traveling vehicle VB and the circle (the circle illustrated by the dashed line in the drawings) defining the outer edge of the predicted collision area ACP to the straight traveling vehicle VB as illustrated in Figs. 13 and 14 is employed as a distance Db from the intersection CS to the straight traveling vehicle VB.

[0061] The HMI device 131a that has received the command signal from the first notification issuing unit B118a issues a notification to promote the driver of the right turning vehicle VA to recognize that the straight traveling vehicle VB traveling toward the intersection CS in the opposite straight lane L22 is present at least using sound. The notification issuance performed by the first notification issuing unit B118a is notification issuance to present information for relatively low urgency in regard to collision between the right turning vehicle VA and the straight traveling vehicle VB.

[0062] The second notification issuing unit B119a outputs a command signal to issue a notification for alarm to the HMI device 131a under a condition that a second predetermined notification issuance condition defined in advance in regard to the position Pb of the straight traveling vehicle VB is established at a second notification issuance timing that the second notification issuance timing setting unit B117a has set.

[0063] The second predetermined notification issuance condition is that the straight traveling vehicle VB is present at a second predetermined distance (hereinafter, referred to as an "alarm distance") Dth2, which is shorter than the information presentation distance Dth1, from the intersection CS or at a position closer to the intersection CS than the second predetermined distance Dth2.

[0064] The notification issuance for alarm is notification issuance at least using sound and is notification issuance using different sound from the notification issuance for information presentation. The HMI device 131a that has received the command signal from the second notification issuing unit B119a issues a notification to promote the driver of the right turning vehicle VA to recognize higher urgency in regard to collision between the right turning vehicle VA and the straight traveling vehicle VB at least using sound. The notification issuance performed by the second notification issuing unit B119a is notification issuance that is more prominent and more auditorily appealing to the driver or is notification issuance that is more prominent and more visually and auditorily appealing to the driver, as compared with the notification issuance performed by the first notification issuing unit B118a.

[0065] The first notification issuing unit B118a and the second notification issuing unit B119a can also provide a notification that the notification in each mode has been issued to the straight traveling vehicle VB via the transmitter 121a in accordance with the output of the command signal to the HMI device 131a and promote a notification to be issued in an appropriate mode in accordance with urgency in regard to collision against the host vehicle (that is, the right turning vehicle VA).

[0066] Fig. 11 is an explanatory diagram illustrating a method of calculating the information presentation distance Dth1 and the alarm distance Dth2.

[0067] The information presentation distance Dth1 and the alarm distance Dth2 are calculated as a distance by which the straight traveling vehicle VB is expected to travel before stopping after the notification issuance, that is, the distance required by the straight traveling vehicle VB to stop on the basis of the vehicle speed VSPb of the straight traveling vehicle VB and deceleration degrees DEC1 and DEC2 set in advance in accordance with the modes of the notification issuance. Hereinafter, the deceleration degree DEC1 may be referred to as a "first predetermined deceleration degree DEC1". The deceleration degree DEC2 may be referred to as a "second predetermined deceleration degree DEC2".

[0068] Specifically, the information presentation distance Dth1 is calculated by adding the distances for which the straight traveling vehicle VB is expected to travel for a break reaction time PRD1 and a deceleration time PRD2 on the basis of the vehicle speed VSPb (= V1) of the straight traveling vehicle VB at the first notification issuance timing that the first notification issuance timing setting unit B116a has set. The break reaction time PRD1 is a total time of a reaction time required for perception, judgment, and operation before the driver actually performs a brake operation after the notification issuance and an operation delay time for the system, hydraulic equipment, and the like in response to the brake operation. In the present embodiment, the break reaction time PRD1 is set in advance as a constant time (= ΔT). The deceleration time PRD2 is a time required for the vehicle to come to a stop after the brake actually starts to work and can be calculated on the basis of the vehicle speed VSPb and the deceleration degree DEC1 (PRD2 = V1 / DEC1). The deceleration degree DEC1 is, for example, - 0.1G. In this manner, the calculation of the information presentation distance Dth1 is given by Equation (1) below. Dth 1 = V 1 × ΔT + V 1 × V 1 / DEC 1 / 2

[0069] Although the alarm distance Dth2 is similarly calculated by adding the distance for which the straight traveling vehicle VB is expected to travel for each of the break reaction time PRD1 and the deceleration time PRD2, the deceleration degree DEC2 which is different from that used to calculate the information presentation distance Dth1 is employed. The deceleration degree DEC2 for calculating the alarm distance is a higher deceleration degree than the deceleration degree DEC1 for calculating the information presentation distance, in other words, a deceleration degree having a larger absolute value than that of the deceleration degree DEC1 (|DEC1| < |DEC2|). The deceleration degree DEC2 is, for example, -0.2G. Specifically, it is given by Equation (2) below. The vehicle speed V1 used in the calculation of the alarm distance Dth2 is the vehicle speed VSPb of the straight traveling vehicle VB at the second notification issuance timing. However, for simplification, the vehicle speed VSPb at the first notification issuance timing may be used instead. Dth 2 = V 1 × ΔT + V 1 × V 1 / DEC 2 / 2

[0070] Returning to Fig. 2, the determination area setting unit B120a sets the intersection area ACS and the predicted collision area ACP. The determination area setting unit B120a sets these areas ACS and ACP in association with the road map, and in the present embodiment, sets these areas ACS and ACP on the map in the range or the section extracted by the road map storage unit B113a.

[0071] Both the intersection area ACS and the predicted collision area ACP can be set to have variable sizes. In the present embodiment, both the intersection area ACS and the predicted collision area ACP are set as circular areas, and the radii thereof, that is, the distances φacs and φacp from the intersection center CTR and the predicted collision point CPP to the outer edges of the areas ACS and ACP, respectively, can be changed. The centers of the areas ACS and ACP are maintained at the intersection center CTR and the predicted collision point CPP before and after the changes in sizes or radii.

[0072] The determination area setting unit B120a sets the intersection area ACS and also sets the predicted collision area ACP at a timing before the right turning vehicle VA reaches the intersection CS after the right turning vehicle VA displays its right turn intention. Then, the size of the predicted collision area ACP is changed in accordance with an actual driving state of the right turning vehicle VA in the intersection area ACS at a timing at which or after the right turning vehicle VA reaches the intersection area ACS after the areas ACS and ACP are set.

[0073] Specifically, the determination area setting unit B120a sets the intersection area ACS to have a size in accordance with the vehicle speed VSPa of the right turning vehicle VA and also sets the predicted collision area ACP to have a predetermined size as a basis at the timing before the right turning vehicle VA reaches the intersection CS. As for the setting of the intersection area ACS, the intersection area ACS is expanded as the vehicle speed VSPa increases.

[0074] On the other hand, the size of the predicted collision area ACP is changed to a size in accordance with the vehicle speed VSPa of the right turning vehicle VA in the intersection area ACS while the size of the intersection area ACS is maintained as a prescribed size, that is, the basic size, at the timing at which or after the right turning vehicle VA reaches the intersection area ACS. Specifically, the predicted collision area ACP is reduced in size as the vehicle speed VSPa decreases. In the present embodiment, the size of the predicted collision area ACP is maintained in a case where the vehicle speed VSPa at the time of or after the arrival at the intersection area ACS is higher than a predetermined vehicle speed Vth2 corresponding to a reduced speed, and the predicted collision area ACP is reduced in size in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed Vth2 and the right turning vehicle VA is in a state of traveling at a reduced speed or is temporarily stopped. For example, the predicted collision area ACP is set to the smallest size in the setting.

[0075] Fig. 15 is a schematic diagram illustrating a setting status in a case where the intersection area ACS is expanded.

[0076] The determination area setting unit B120a sets the intersection area ACS to have a size in accordance with the vehicle speed VSPa of the right turning vehicle VA before the right turning vehicle VA reaches the intersection CS. In other words, the setting of the intersection area ACS is performed at the timing when the right turning vehicle VA is located at a position spaced apart from the intersection CS, and the setting of the size and the radius φacs of the intersection area ACS is performed based on a pre-notification issuance time Ppre in accordance with the vehicle speed VSPa of the right turning vehicle VA and the vehicle speed VSPb of the straight traveling vehicle VB.

[0077] The determination area setting unit B120a has a preset deceleration rate DEC1 and detects the vehicle speeds VSPa and VSPb of the right turning vehicle VA and the straight traveling vehicle VB, respectively, at the timing illustrated in Fig. 15 before the right turning vehicle VA reaches the intersection CS. In the present embodiment, the deceleration rate DEC1 is the same as the predetermined deceleration rate DEC1 used for calculating the previously mentioned information presentation distance Dth1.

[0078] Referring to Fig. 11, the determination area setting unit B120a calculates the pre-notification issuance time Ppre until the vehicle speed VSPb of the straight traveling vehicle VB decreases to zero at the deceleration rate DEC1 from the current vehicle speed (= V1). The calculation of the pre-notification issuance time Ppre is performed by Equation (3) below. Considering a brake reaction time ΔT after the notification issuance, Equation (4) below may be adopted. Ppre = VSPb / DEC 1 Ppre = ΔT + VSPb / DEC 1

[0079] Then, the determination area setting unit B120a multiplies the pre-notification issuance time Ppre by the vehicle speed VSPa of the right turning vehicle VA and sets the thus obtained distance as the radius φacs of the intersection area ACS. φacs = Ppre × VSPa

[0080] Note that in the present embodiment, the determination area setting unit B120a sets an intersection area (hereinafter, referred to as "expanded intersection area") ACSe is defined by enlarging the area or radius φacs based on the vehicle speeds VSPa and VSPb when the vehicle speed VSPa is higher than a predetermined vehicle speed, and sets an intersection area (hereinafter, referred to as "basic intersection area" in some times) ACSb, which has a standard predetermined area or radius φacs, is defined when the vehicle speed VSPa is equal to or lower than the predetermined vehicle speed.

[0081] Fig. 16 is a schematic diagram illustrating a setting status in a case where the predicted collision area ACP is reduced in size.

[0082] As mentioned earlier, the size of the predicted collision area ACP is reduced to the smallest size in the setting in a case where the right turning vehicle VA is in a state of traveling at a reduced speed or is temporarily stopped at a timing before the right turning vehicle VA reaches the predicted collision area ACP after the right turning vehicle VA enters the intersection area ACS in the present embodiment. The predicted collision area ACP with the smallest size has a diameter that substantially coincides with a lane width W of the lane where the straight traveling vehicle VB is traveling, that is, the straight traveling lane L22 (φacp × 2 = W).

[0083] In addition to the above, the controller 101a includes the pedestrian detection unit B121a and a third notification issuing unit B122a.

[0084] The pedestrian detection unit B121a detects a pedestrian who is present in the intersection surrounding area AAC, for example, a pedestrian crossing the crosswalk PC3 after the right turn of the right turning vehicle VA. In the present embodiment, the detection of a pedestrian is based on position information in regard to the pedestrian that can be acquired from the mobile communication device (a smartphone, for example) 201 that the pedestrian has. The pedestrian detection unit B121a identifies the position of the pedestrian on the road map from the acquired position information and determines that the position of the pedestrian is within the range of the map set as the intersection surrounding area AAC.

[0085] The third notification issuing unit B122a outputs a command signal to perform notification issuance to promote the host vehicle (that is, the right turning vehicle VA) to pay attention to the pedestrian (hereinafter, referred to as "pedestrian caution notification issuance") to the HMI device 131a included in the host vehicle in a case where the pedestrian detection unit B121a detects the pedestrian in the intersection surrounding area AAC. It is preferable that the notification issuance based on the command from the third notification issuing unit B122a, that is, the pedestrian caution notification issuance be typically performed at a timing other than the timings at which the notification issuances for information presentation and alarm are performed for the right turning vehicle VA. This can be realized by selecting a timing other than the timings at which the commands for information presentation and alarm are provided and detecting the pedestrian at the timing, and in a case where a command to perform the notification issuance for information presentation or alarm and a command to perform pedestrian caution notification issuance occur at the same time, this can also be realized by placing priority on the notification issuance based on the former command. In the present embodiment, the third notification issuing unit B122a outputs a signal to notify the controller 101b of the fact that the pedestrian caution notification issuance has been performed, in addition to the output of the command signal to the HMI device 131a. The controller 101b performs notification issuance to promote the host vehicle (that is, the straight traveling vehicle VB) to pay attention to the right turning vehicle VA on the basis of the signal. As described above, in the present embodiment, the third notification issuing unit B122a is equipped with both a function to perform pedestrian caution notification issuance and a function to perform notification issuance to promote the straight traveling vehicle VB to pay attention to the right turning vehicle VA when the right turning vehicle VA detects a pedestrian by the pedestrian detection unit B121a. Here, these notification issuances triggered by the detection of a pedestrian may be referred to as "notification issuance to call for attention", distinguishing them from the notification issuances for information presentation and alarm. The pedestrian caution notification issuance corresponds to the "notification issuance in the second mode" for the right turning vehicle VA, and the notification issuance to promote the straight traveling vehicle VB to pay attention corresponds to the "notification issuance in the third mode".

[0086] Fig. 17 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at the timing at which the pedestrian caution notification issuance is performed.

[0087] In the present embodiment, it is preferable that the pedestrian caution notification issuance be performed in a case where the straight traveling vehicle VB is located at a position farther from the intersection CS than the information presentation distance Dth1 at a timing after the right turning vehicle VA enters the intersection area ACS. At the timing illustrated in Fig. 17, the controller 101a does not perform the notification issuance for information presentation since the straight traveling vehicle VB is not present at the information presentation distance Dth1 from the intersection CS and at the position closer to the intersection CS than the information presentation distance Dth1.

[0088] In other words, it is preferable that the pedestrian caution notification issuance be performed under a condition that the pedestrian has been detected in the intersection surrounding area AAC in a case where the notification issuance for information presentation is not performed by the straight traveling vehicle VB being located at a position farther from the intersection CS than the information presentation distance Dth1 after the right turning vehicle VA enters the intersection area ACS in the present embodiment. Then, the pedestrian caution notification issuance is stopped, and the notification issuance for information presentation in regard to collision between the right turning vehicle VA and the straight traveling vehicle VB is performed, at a timing at which the straight traveling vehicle VB has traveled forward and approached the information presentation distance Dth1 from the intersection CS. Furthermore, in a case where the right turning vehicle VA has entered the predicted collision area ACP and the straight traveling vehicle VB has also approached the alarm distance Dth2 from the intersection CS or a position closer to the intersection CS than the alarm distance Dth2, the mode for the notification issuance is switched from the information presentation to the alarm.

[0089] The HMI device 131a, which has received the command signal from the third notification issuing unit B122a, produces at least sound as the pedestrian caution notification issuance. In the present embodiment, the pedestrian caution notification issuance is performed in response to transmission of a command from the third notification issuing unit B122a to the HMI device 131a. Also, when the pedestrian caution notification issuance is performed, different sound is adopted between a case where the right turning vehicle VA is located in the predicted collision area ACP and a case where the right turning vehicle VA is not located in the predicted collision area ACP. When the pedestrian caution notification issuance is performed, different display may be further adopted between a case where the right turning vehicle VA is located in the predicted collision area ACP and a case where the right turning vehicle VA is not located in the predicted collision area ACP. Specifically, notification issuance for the purpose of promoting the driver of the right turning vehicle VA to recognize the presence of the pedestrian in the intersection surrounding area AAC in a case where the right turning vehicle VA is located outside the predicted collision area ACP and a relatively long time has been secured for the right turning vehicle VA to reach the crosswalk PC3 after the right turn, while notification issuance for the purpose of promoting the driver to perform an operation to avoid contact with the pedestrian in a case where the right turning vehicle VA is located in the predicted collision area ACP and has approached a location right before the crosswalk PC3 after the right turn.

[0090] The sound and the display used when the pedestrian caution notification issuance is performed, in other words, the mode for the pedestrian caution notification issuance may be different not only between the case where the right turning vehicle VA is located in the predicted collision area ACP and the case where the right turning vehicle VA is not located in the predicted collision area ACP but also between a case where the right turning vehicle VA is traveling at the vehicle speed VSPa that is higher than a predetermined vehicle speed toward the predicted collision point CPP outside the predicted collision area ACP or is located in the predicted collision area ACP and the other case, that is, a case where the right turning vehicle VA is located outside the predicted collision area ACP and the vehicle speed VSPa is lower than the predetermined vehicle speed.

[0091] In the present embodiment, the controller 101a included in the right turning vehicle VA and the controller 101b included in the straight traveling vehicle VB have basically similar configurations and include mutually corresponding elements.

[0092] As illustrated in Fig. 3, the controller 101b includes a host vehicle position detection unit B111b, an other vehicle position detection unit B112b, a road map storage unit B113b, a right turn intention detection unit B114b, a driving state detection unit B115b, a first notification issuance timing setting unit B116b, a second notification issuance timing setting unit B117b, a first notification issuing unit B118b, a second notification issuing unit B119b and a determination area setting unit B120b. Although the controller 101b may include components corresponding to the pedestrian detection unit B121a and the third notification issuing unit B122a, these components are not illustrated because, in the present embodiment, they are not required elements for the straight traveling vehicle VB. Differences between an internal configuration of the controller 101b and that of the controller 101a will be mainly described below.

[0093] The host vehicle position detection unit B111b is adapted to detect the current position Pb of the straight traveling vehicle VB, which is the host vehicle, and the detection of the current position Pb is based on an output signal from the position sensor 111b included in the straight traveling vehicle VB.

[0094] The other vehicle position detection unit B112b is adapted to detect the current position Pa of the right turning vehicle VA, which is another vehicle, and the detection of the current position Pa is based on reading of position information indicating the current position Pa from vehicle information acquired from the right turning vehicle VA via the receiver 122b included in the straight traveling vehicle VB.

[0095] Similarly to the road map storage unit B113a, the road map storage unit B113b stores a road map that includes the intersection CS and includes the assigned link ID of each lane leading to the intersection CS and specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA, respectively, on the road map. Although the road maps stored in the road map storage units B113b and B113a may have different levels of accuracy, both the maps employ an accuracy that is compatible with satellite positioning using GNSS in the present embodiment.

[0096] The right turn intention detection unit B114b is adapted to detect a right turn intention of the right turning vehicle VA, and the detection of the right turn intention is based on identification of the link ID of the lane where the right turning vehicle VA is present from the current position Pa of the right turning vehicle VA or reading of information indicating an operating status of the right turn signal from vehicle information acquired from the right turning vehicle VA via the receiver 122b. It is also possible to include the link IDs of the lanes where the vehicles VA and VB are present in vehicle information exchanged between the straight traveling vehicle VB and the right turning vehicle VA and to detect the right turn intention of the right turning vehicle VA on the basis of the link IDs acquired through communication.

[0097] The driving state detection unit B115b is adapted to detect the vehicle speed VSPa of the right turning vehicle VA as the driving state of the right turning vehicle VA, and the detection of the vehicle speed VSPa is based on reading of vehicle speed information indicating the vehicle speed VSPa from vehicle information acquired from the right turning vehicle VA via the receiver 122b.

[0098] The first notification issuance timing setting unit B116b detects that the right turning vehicle VA is located at a predetermined relative position to the intersection CS after showing its right turn intention based on the current position Pa of the right turning vehicle VA on the road map. Specifically, the first notification issuance timing setting unit B116b compares the current position Pa of the right turning vehicle VA with the intersection area ACS and detects that the right turning vehicle VA has arrived at the intersection area ACS or has entered the intersection area ACS similarly to the above description. And then, the first notification issuance timing setting unit B116b sets the detected timing as the first notification issuance timing. The first notification issuance timing set by the first notification issuance timing setting unit B116b is the timing at which the notification issuance for information presentation is executed in the straight traveling vehicle VB. The notification issuances performed at the first notification issuance timing and the second notification issuance timing described below, or notification issuances for information presentation and alarm that the controller 101b executes correspond to the "notification issuance in the first mode" directed at the straight traveling vehicle VB.

[0099] The size and the shape of the intersection area ACS may be the same or different between the controller 101a and the controller 101b. It is possible to set the shape of the intersection area ACS to be variable between those controllers 101a and 101b in accordance with a drivers' selection or trends of driving states at the time of passing the intersection CS, for example.

[0100] The second notification issuance timing setting unit B117b monitors the behavior of the right turning vehicle VA after entering the intersection CS based on the current position Pa of the right turning vehicle VA on the road map and detects that the right turning vehicle VA is traveling toward the predicted collision point CPP in the intersection area ACS or present in the predicted collision area ACP after entering the intersection area ACS. And then, the second notification issuance timing setting unit B117b sets the timing at which anyone of those behaviors is detected in the right turning vehicle VA as the second notification issuance timing. The second notification issuance timing set by the second notification issuance timing setting unit B117b is the timing at which the notification issuance for alarm is executed in the straight traveling vehicle VB.

[0101] Although the size and the shape of the predicted collision area ACP may be different between the controller 101a and the controller 101b, similar setting is adopted for both in the present embodiment. The predicted collision area ACP may be set to have the same size and shape in both controller 101a and controller 101b, or coordinate information of the predicted collision area ACP set in one of the controllers 101a and 101b may be provided to and set in the other controller through vehicle-to-vehicle communication.

[0102] The first notification issuing unit B118b outputs a command signal to issue the notification for information presentation to the HMI device 131b included in the host vehicle (that is, the straight traveling vehicle VB) under a condition that the first predetermined notification issuance condition related to the position Pb of the straight traveling vehicle VB is established at the first notification issuance timing set by the first notification issuance timing setting unit B116b. Similarly to the above description, the first predetermined notification issuance condition is that the straight traveling vehicle VB is located at the information presentation distance Dth1 from the intersection CS or is present at a position closer to the intersection CS than the information presentation distance Dth1.

[0103] The HMI device 131b that has received the command signal from the first notification issuing unit B118b issues a notification to promote the driver of the straight traveling vehicle VB to recognize that the right turning vehicle VA which the driver should pay attention to is present in the right turn lane L11 in the opposite lanes at least using sound. Similarly to the above description, the notification issuance performed by the first notification issuing unit B118b is notification issuance to present information for relatively low urgency in regard to collision between the straight traveling vehicle VB and the right turning vehicle VA.

[0104] The second notification issuing unit B119b outputs a command signal to issue the notification for alarm to the HMI device 131b under a condition that the second predetermined notification issuance condition related to the position Pb of the straight traveling vehicle VB is established at the second notification issuance timing set by the second notification issuance timing setting unit B117b. The second predetermined notification issuance condition is that the straight traveling vehicle VB is located at the alarm distance Dth2 from the intersection CS or is present at a position closer to the intersection CS than the alarm distance Dth2.

[0105] The HMI device 131b that has received the command signal from the second notification issuing unit B119b issues a notification to promote the driver of the straight traveling vehicle VB to recognize higher urgency in regard to collision between the straight traveling vehicle VB and the right turning vehicle VA at least using sound. Similarly to the above description, the notification issuance performed by the second notification issuing unit B119b is also notification issuance that is more prominent and more auditorily appealing to the driver or is more prominent and more visually and auditorily appealing to the driver.

[0106] The first notification issuing unit B118b and the second notification issuing unit B119b can also notify the right turning vehicle VA of the fact that the notification in each mode has been issued via the transmitter 121b in accordance with the output of the command signal to the HMI device 131b.

[0107] The determination area setting unit B120b sets the intersection area ACS and the predicted collision area ACP. Similarly to the above description, the determination area setting unit B120b sets these areas ACS and ACP on the map in the range or the section extracted by the road map storage unit B113b.

[0108] The intersection area ACS and the predicted collision area ACP can also be set to have variable sizes by the controller 101b, and both the intersection area ACS and the predicted collision area ACP are set as circular areas, allowing the radii thereof, that is, the distances φacs and φacp from the intersection center CTR and the predicted collision point CPP to the outer edges of the areas ACS and ACP to be changed.

[0109] The determination area setting unit B120b sets the intersection area ACS and the predicted collision area ACP at a timing before the right turning vehicle VA reaches the intersection CS after the right turn intention of the right turning vehicle VA is detected.

[0110] In the present embodiment, the setting of the intersection area ACS and the predicted collision area ACP by the determination area setting unit B120b follows a procedure similar to that for the setting of the areas ACS and ACP by the determination area setting unit B120a.

[0111] Specifically, the determination area setting unit B120b sets the intersection area ACS to have a size corresponding to the vehicle speed VSPa of the right turning vehicle VA and sets the predicted collision area ACP to have a predetermined base size at the timing before the right turning vehicle VA reaches the intersection CS. The configuration of the intersection area ACS is based on expanding the intersection area ACS as the vehicle speed VSPa increases. The determination area setting unit B120b modifies the size of the predicted collision area ACP to a size in accordance with the vehicle speed VSPa of the right turning vehicle VA in the intersection area ACS at a timing after the right turning vehicle VA reaches the intersection area ACS or after the right turning vehicle VA reaches the intersection area ACS, and contracts the predicted collision area ACP to have a reduced size as the vehicle speed VSPa decreases. In the present embodiment, in a case where the vehicle speed VSPa at the time of or after reaching the intersection area ACS is equal to or less than the predetermined vehicle speed Vth2, and the right turning vehicle VA is in a slowed-down state or in a temporarily stopped state inside the intersection area ACS, the predicted collision area ACP is reduced in size to the smallest size in terms of setting, specifically, to have a diameter that substantially corresponds to the lane width W of the straight traveling lane L22.

[0112] It is desirable that the notifications for the drivers do not hinder driving of the drivers and be easy for the drivers to know targets to which attention is to be paid. In other words, it is desirable that the notification issuance performed when the right turning vehicle VA turns right at the intersection CS enable the driver of the right turning vehicle VA to easily recognize whether the target to which attention is to be paid is the straight traveling vehicle VB or the object to be monitored.

[0113] Therefore, the notification issuance in the first mode and the notification issuance in the second mode are performed with mutually different sounds via the HMI device 131a as the output unit in the right turning vehicle VA.

[0114] Specifically, a voice such as "There is a straight traveling vehicle", "A straight traveling vehicle is there", or "A straight traveling vehicle is right there", for example, is emitted from the speaker 141a of the HMI device 131a in accordance with a situation in the notification issuance in the first mode in the right turning vehicle VA. Also, a voice such as "There is a pedestrian", "A pedestrian is there", or "A pedestrian is right there", for example, is emitted from the speaker 141a of the HMI device 131a in accordance with a situation in the notification issuance in the second mode in the right turning vehicle VA. Such a notification issuance with a voice based on a relatively short sentence enables the driver to understand the content of the notification in a short period of time without his / her driving being hindered. Therefore, the driver of the right turning vehicle VA can easily identify the notification issuance in the first mode and the notification issuance in the second mode by a difference in voices, that is, a difference in content of the notifications by the voices. Therefore, the driver can accurately recognize, on the basis of the different voices, that is, the different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode without his / her driving being hindered even in a situation where the driver is focusing on the front side for driving.

[0115] Fig. 22 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the right turning vehicle.

[0116] Fig. 23 is a schematic diagram illustrating an example of the notification issuance in the second mode through display in the notification control performed in the right turning vehicle.

[0117] Furthermore, as illustrated in Figs. 22 and 23, the notification issuance in the first mode and the notification issuance in the second mode are preferably performed through different displays via the HMI device 131a in the right turning vehicle VA. This enables the driver of the right turning vehicle VA to more accurately recognize, on the basis of different displays in addition to different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode.

[0118] Specifically, as illustrated in Fig. 22, information VBT indicating the type of the straight traveling vehicle VB, which is the counterpart vehicle of the right turning vehicle VA, and information VBTD indicating the traveling direction (straight traveling direction) of the straight traveling vehicle VB are displayed in a display region DAa that a display 143a of the HMI device 131a has in the right turning vehicle VA on the basis of the straight traveling vehicle information related to the straight traveling vehicle VB obtained via communication between the right turning vehicle VA and the straight traveling vehicle VB in the notification issuance in the first mode. In the example in Fig. 22, the information VBT indicating a four-wheeled vehicle as the type of the straight traveling vehicle VB is displayed by illustration, and the information VBTD indicating the straight traveling direction as the traveling direction of the straight traveling vehicle VB is displayed by illustration and text. The information VBTD includes information VBTD1 displayed by illustration and information VBTD2 displayed by text. Note that the content of the notification issuance in the first mode through display and the content of the notification issuance in the frist mode through sound do not need to be completely identical. This premise in the notification issuance in the first mode is also applicable to the notification issuance in the second mode and the notification issuance in the third mode.

[0119] As illustrated in Fig. 23, information PE indicating presence of the object to be monitored detected by the pedestrian detection unit B121a is displayed in the display region DAa that the display 143a of the HMI device 131a has in the right turning vehicle VA in the notification issuance in the second mode. In the example in Fig. 23, the information PE is displayed by illustration and text. The information PE includes information PE1 displayed by illustration and information PE2 displayed by text.

[0120] Fig. 24 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the straight traveling vehicle.

[0121] Note that as illustrated in Fig. 24, information VAT indicating the type of the right turning vehicle VA, which is the counterpart vehicle of the straight traveling vehicle VB, and information VATD indicating the traveling direction (right turning direction) of the right turning vehicle VA are preferably displayed in a display region DAb that a display 143b of the HMI device 131b has in the straight traveling vehicle VB on the basis of right turning vehicle information related to the right turning vehicle VA obtained via communication between the right turning vehicle VA and the straight traveling vehicle VB in the notification issuance in the first mode. In the example of Fig. 24, the information VAT is displayed by illustration, and the information VATD is displayed by illustration and text. The information VATD includes information VATD1 displayed by illustration and information VATD2 displayed by text. In the notification issuance in the first mode through display in the right turning vehicle VA, it is preferable that the information VBT indicating the type of the straight traveling vehicle VB and the information VBTD indicating the traveling direction of the straight traveling vehicle VB be displayed in a first color in the display region DAa on the display 143a in the notification issuance for information presentation, and the information VBT and the information VBTD be displayed in a second color, which is different from the first color, in the display region DAa on the display 143a in the notification issuance for alarm. Similarly, in the notification issuance in the first mode through display in the straight traveling vehicle VB, it is preferable that the information VAT and the information VATD be displayed in the first color in the display region DAb on the display 143b in the notification issuance for information presentation, and the information VAT and the information VATD be displayed in the second color in the display region DAb on the display 143b in the notification issuance for alarm. The first color is, for example, yellow, and the second color is, for example, red.

[0122] Furthermore, it is preferable that the notification issuance in the first mode be performed with different sounds in a case where the right turning vehicle VA is present in the expanded intersection area ACSe and in a case where the right turning vehicle VA is present in the intersection area ACS other than the expanded intersection area ACSe, that is, in the basic intersection area ACSb.

[0123] Specifically, the driver of the right turning vehicle VA can recognize the straight traveling vehicle VB that is a target to which attention is to be paid in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to allow the distance before arrival at the intersection CS to become relatively long, which leads to extra time, by the driver of the right turning vehicle VA identifying the notification issuance in the first mode by the sound in the case where the right turning vehicle VA is present in the expanded intersection area ACSe. Therefore, the driver of the right turning vehicle VA can execute a safer action to avoid collision against the straight traveling vehicle VB at the timing at which the right turning vehicle VA reaches the intersection CS. Similarly, the driver of the straight traveling vehicle VB can recognize the right turning vehicle VA that is a target to which attention is to be paid in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to allow the distance before arrival at the intersection CS to become relatively long, which leads to extra time, by the driver of the straight traveling vehicle VB identifying the notification issuance in the first mode by the sound in the case where the right turning vehicle CA is present in the expanded intersection area ACSe. Therefore, the driver of the straight traveling vehicle VB can execute a safer action to avoid collision against the right turning vehicle VA just in a case where the right turning vehicle VA tries to turn right at the intersection CS before the straight traveling vehicle VB passes the intersection CS.

[0124] Note that in the notification issuance in the first mode, a voice "There is a straight traveling vehicle", for example, in a case where the right turning vehicle VA is present in the expanded intersection area ACSe or a voice "A straight traveling vehicle is there", for example, in a case where the right turning vehicle VA is present in the basic intersection area ACSb is emitted from the speaker 141a of the HMI device 131a in the right turning vehicle VA. Also, in the notification issuance in the first mode, a voice "There is a right turning vehicle", for example, in a case where the right turning vehicle VA is present in the expanded intersection area ACSe or a voice "A right turning vehicle is there", for example, in a case where the right turning vehicle VA is present in the basic intersection area ACSb is emitted from the speaker 141b of the HMI device 131b in the straight traveling vehicle VB.

[0125] Furthermore, the notification issuance in the second mode is preferably performed with different sounds in the case where the right turning vehicle VA is present in the expanded intersection area ACSe and in the case where the right turning vehicle VA is present in the intersection area ACS other than the expanded intersection area ACSe, that is, in the basic intersection area ACSb. In this manner, the driver of the right turning vehicle VA can recognize object to be monitored that is a target to which attention is to be paid, in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Therefore, the driver can execute a safer action to avoid collision against the object to be monitored that is a target to which attention is to be paid, at the timing at which the right turning vehicle VA reaches the intersection CS.

[0126] Note that in the notification issuance in the second mode, a voice "there is a pedestrian", for example, in a case where the right turning vehicle VA is present in the expanded intersection area ACSe or a voice "A pedestrian is right there", for example, in a case where the right turning vehicle VA is present in the basic intersection area ACSb is emitted from the speaker 141a of the HMI device 131a.

[0127] Also, the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB are preferably performed with the same sound.

[0128] Specifically, the driver of the straight traveling vehicle VB typically does not have to pay attention to the object to be monitored when passing the intersection CS. Therefore, the driver of the straight traveling vehicle VB can pay attention only to the right turning vehicle VA by performing the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB with the same sound. In other words, it is possible to provide a notification that does not hinder driving of the driver of the straight traveling vehicle VB by performing the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB with the same sound in a case where the target to which attention is to be paid does not change and is still the right turning vehicle VA.

[0129] Note that in the notification issuance in the first mode and the notification issuance in the third mode in the straight traveling vehicle VB, a voice "There is a right turning vehicle", "A right turning vehicle is right there", or "A right turning vehicle is right there", for example, is emitted from the speaker 141b of the HMI device 131b in accordance with a situation.

[0130] Moreover, it is preferable that the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB be further performed through the same display. In other words, it is preferable that the notification issuance in the third mode be also fourther performed through display illustrated in Fig. 24. By doing so, the driver of the straight traveling vehicle VB can pay attention only to the right turning vehicle VA to which it is necessary to pay attention even in a case where an object to be monitored to which it is not necessary to pay attention is detected at the intersection CS or in the intersection surrounding area AAC, which is a predetermined area around the intersection CS. In other words, it is possible to reliably provide a notification that does not hinder driving of the driver of the straight traveling vehicle VB by performing the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB through the same display in addition to the same sound in a case where the target to which attention is to be paid does not change and is still the right turning vehicle VA.

[0131] Additionally, the first notification issuing unit B118a and the third notification issuing unit B122a may perform notification issuance in a fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects the object to be monitored when the notification issuance in the first mode is being performed as notification issuance for information presentation. Furthermore, the second notification issuing unit B119a and the third notification issuing unit B122a may perform the notification issuance in the fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode as notification issuance for alarm, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects an object to be monitored when the notification issuance in the first mode as notification issuance for alarm is being performed.

[0132] Specifically, if a command signal from the third notification issuing unit B122a is further received in a situation where a command signal from the first notification issuing unit B118a has been received and the notification issuance for information presentation is being performed, then the HMI device 131a emits a voice "There are a straight traveling vehicle and a pedestrian" or "A straight traveling vehicle and a pedestrian are right there", for example, from the speaker 141a as the notification issuance in the fourth mode. Additionally, if a command signal from the third notification issuing unit B122a is further received in a situation where a command signal from the second notification issuing unit B119a has been received and the notification issuance for alarm is being performed, then the HMI device 131a emits a voice "A straight traveling vehicle and a pedestrian are right there", for example, from the speaker 141a as the notification issuance in the fourth mode. In other words, the notification issuance in the fourth mode with a sound is configured of content of notification as a combination of content of notification with a sound in the notification issuance in the first mode and content of notification with a sound in the notification issuance in the second mode. By doing so, it is possible to make the driver of the right turning vehicle VA aware of presence of a pedestrian by notification issuance in the fourth mode based on a sound and to promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm.

[0133] Fig. 25 is a schematic diagram illustrating an example of the notification issuance in the fourth mode through display in notification control performed in the right turning vehicle.

[0134] Additionally, the notification issuance in the fourth mode may be further performed through display.

[0135] Specifically, if the HMI device 131a further receives a command signal from the third notification issuing unit B122a in a situation where a command signal from the first notification issuing unit B118a has been received and notification issuance for information presentation is being performed or in a situation where a command signal from the second notification issuing unit B119a has been received and notification issuance for alarm is being performed through display on a screen as illustrated in Fig. 22 in the display region DAa on the display 143a, then the HMI device 131a displays a screen as illustrated in Fig. 25 in the display region DAa on the display 143a as the notification issuance in the fourth mode. In the example in Fig. 25, the information VBT indicating the type of the straight traveling vehicle VB and the information PE1 indicating the presence of the object to be monitored are displayed by illustration in the upper section in the display region DAa. Furthermore, the information VBTD1 indicating the traveling direction of the straight traveling vehicle VB is displayed by illustration in the middle section in the display region DAa. Information Combo indicating the presence of the straight traveling vehicle VB and the pedestrian as the target to be monitored is displayed by text in the lower section in the display region DAa. As illustrated in Figs. 22, 23, and 25, the notification issuance in the fourth mode through display is configured of content of notification as a combination of content of notification in the notification issuance in the first mode through display and content of notification in the notification issuance in the second mode through display. By doing so, it is possible to make the driver of the right turning vehicle VA aware of the presence of the pedestrian by the notification issuance in the fourth mode based on the display in addition to the sound and to reliably promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm. Note that similarly to the notification issuance in the first mode, the content of the notification issuance in the fourth mode through display and the content of the notification issuance in the fourth mode through sound also do not need to be completely identical.

[0136] In the notification system 1, it is preferable that notification issuance at least with a sound be performed until a predetermined word, a predetermined phrase, or a predetermined sentence representing content of notification is read at least once or more in a case where completion of passing of the right turning vehicle VA through the intersection CS is detected on the basis of results of specification by the road map storage units B113a and B113b when the notification issuance at least with a voice is being performed. This enables the driver to more accurately understand the content of the notification because the read content of notification does not end in the middle.

[0137] Note that examples of the predetermined sentence include "There is a straight traveling vehicle", "There is a right turning vehicle", and "There is a pedestrian" as described above. The predetermined phrase means a further shortened expression from each of these predetermined sentences, and the predetermined word means a single characteristic word from the predetermined sentence or the predetermined phrase. Additionally, the notification through display may be ended at the same time with the end of the notification issuance with a sound in a case where the notification issuance through display is performed together.(Content of Notification Control in Right Turning Vehicle)

[0138] Figs. 4 to 10 are flowcharts illustrating content of notification control performed by the controller 101a included in the right turning vehicle VA. The flowchart in Fig. 4 illustrates an overall flow of the notification control, the flowcharts in Figs. 5 to 7 illustrate content of early notification issuance processing, and the flowcharts in Figs. 8 to 10 illustrate content of normal notification issuance processing. The flowcharts in Figs. 6 and 9 illustrate content of processing (information presentation processing) executed by the right turning vehicle VA in regard to information presentation, and the flowcharts in Figs. 7 and 10 illustrate content of processing (alarm processing) executed by the right turning vehicle VA in regard to an alarm. The information presentation processing and the alarm processing are performed as parts of the notification control. The controller 101a performs the notification control every predetermined time in a case where an intersection is detected in a road in front of the host vehicle (that is, the right turning vehicle VA).

[0139] In the flowchart illustrated in Fig. 4, the controller 101a reads various kinds of control information used for the notification control in S111. The control information read in S111 includes the current position Pa, the vehicle speed VSPa and the link ID of the right turning vehicle VA which is the host vehicle, and the current position Pb, the vehicle speed VSPb and the link ID of the straight traveling vehicle VB which is another vehicle. The control information may include information regarding operating statuses of the right turn signals in the right turning vehicle VA and the straight traveling vehicle VB.

[0140] In S112, the controller 101a determines whether or not the straight traveling vehicle VB traveling in the straight direction toward the intersection CS in the lane L22 opposite to the lane L11 in which the right turning vehicle VA is present has been detected. The detection of the straight traveling vehicle VB is based on the link ID of the straight traveling vehicle VB. The processing proceeds to S113 in a case where the straight traveling vehicle VB is detected, or this control is ended in a case where the straight traveling vehicle VB is not detected.

[0141] In S113, the controller 101a determines whether or not a right turn intention of the right turning vehicle VA has been detected. The detection of the right turn intention is based on an operating status of the right turn signal of the right turning vehicle VA. Additionally or alternatively, it is also possible to make the determination on the basis of the link ID of the right turning vehicle VA. The processing proceeds to S114 in a case where the right turn intention is detected, or this control is ended in a case where the right turn intention is not detected.

[0142] In S114, the controller 101a reads the vehicle speed VSPa of the right turning vehicle VA. At the timing at which the right turn intention is detected, the right turning vehicle VA is located at a position separated from the intersection CS, that is, a position before reaching the intersection CS, and the vehicle speed VSPa at the timing at which the right turn intention is detected is the vehicle speed VSPa before the right turning vehicle VA reaches the intersection CS.

[0143] In S115, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB, specifically the vehicle speed VSPb at the timing at which the right turn intention of the right turning vehicle VA is detected.

[0144] In S116, the controller 101a sets the intersection area ACS and the predicted collision area ACP as determination areas. The setting of the intersection area ACS is based on the vehicle speed VSPa of the right turning vehicle VA and the vehicle speed VSPb of the straight traveling vehicle VB at the timing at which the right turn intention is detected. In the present embodiment, when the vehicle speed VSPa is higher than a predetermined vehicle speed, the expanded intersection area ACSe is set according to the vehicle speeds VSPa and VSPb, and when the vehicle speed VSPa is equal to or lower than the predetermined vehicle speed, the basic intersection area ACSb is set. In this embodiment, the predicted collision area ACP is set to have the same area or radius φacp regardless of whether the vehicle speed VSPa is above or below the predetermined vehicle speed. However, it is also possible to vary the size of the predicted collision area depending on the vehicle speed, such that in a case where the vehicle speed VSPa is higher than the predetermined vehicle speed, the predicted collision area ACP is expanded in conjunction with the setting of the expanded intersection area ACSe.

[0145] In 117, the controller 101a determines whether or not the expanded intersection area ACSe has been set. The processing proceeds to S118 in a case where the expanded intersection area ACSe has been set, or the processing proceeds to S119 in a case where the basic intersection area ACSb has been set, or the expanded intersection area ACSe has not been set.

[0146] In S118, the controller 101a performs early notification issuance processing using the expanded intersection area ACSe and the predicted collision area ACP.

[0147] In S119, the controller 101a performs normal notification issuance processing using the basic intersection area ACSb and the predicted collision area ACP.

[0148] In the flowchart illustrated in Fig. 5, the controller 101a reads various kinds of control information used for early notification issuance processing in S211. The control information read in S211 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0149] In S212, the controller 101a specifies the current position Pa of the right turning vehicle VA on the road map.

[0150] In S213, the controller 101a determines whether or not the right turning vehicle VA has entered the expanded intersection area ACSe. In a case where the right turning vehicle VA is located at a position of the outer edge of the expanded intersection area ACSe or is located at a position closer to the intersection center CTR than the outer edge, the right turning vehicle VA is determined to have entered the expanded intersection area ACSe, and the processing proceeds to S214. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the intersection center CTR than the outer edge of the expanded intersection area ACSe, the right turning vehicle VA is determined not to have entered the expanded intersection area ACSe, and this control is ended.

[0151] In S214, the controller 101a performs the information presentation processing for early notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 6.

[0152] In S215, the controller 101a performs the alarm processing for early notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 7.

[0153] In S216, the controller 101a determines whether or not notification issuance has been performed in the information presentation processing or the alarm processing for early notification issuance. The processing proceeds to S219 in a case where the notification issuance has been performed, or the processing proceeds to S217 in a case where the notification issuance has not been performed.

[0154] In S217, the controller 101a determines whether or not a pedestrian has been detected in the intersection surrounding area AAC. The processing proceeds to S218 in a case where a pedestrian has been detected, or the processing proceeds to S219 in a case where no pedestrians have been detected.

[0155] In S218, the controller 101a performs pedestrian caution notification issuance.

[0156] In S219, the controller 101a determines whether or not the right turning vehicle VA has passed the intersection CS. The determination of whether or not the right turning vehicle VA has passed the intersection CS is made on the basis of the fact that the right turning vehicle VA has left the expanded intersection area ACSe in the traveling direction after the right turn. The right turning vehicle VA is determined to have passed the intersection CS and this control is ended in a case where the right turning vehicle VA has left the expanded intersection area ACSe, or the right turning vehicle VA is determined not to have passed the intersection CS, the processing returns to S214, and the information presentation processing and the alarm processing are repeatedly executed until the right turning vehicle VA leaves the expanded intersection area ACSe in a case where the right turning vehicle VA is still located in the expanded intersection area ACSe.

[0157] In the flowchart illustrated in Fig. 6, the controller 101a reads various kinds of control information used for the information presentation processing in S311. The control information read in S311 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0158] In S312, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0159] In S313, the controller 101a determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP. In a case where the right turning vehicle VA is located at a position between the outer edge of the intersection area ACS and the outer edge of the predicted collision area ACP, the right turning vehicle VA is determined to be located outside the predicted collision area ACP, and the processing proceeds to S314. On the other hand, in a case where the right turning vehicle VA is located at the outer edge of the predicted collision area ACP or a position closer to the predicted collision point CPP than the outer edge, the right turning vehicle VA is determined not to be located outside the predicted collision area ACP, and the information presentation processing is ended.

[0160] In S314, the controller 101a calculates the distance from intersection CS to the straight traveling vehicle VB, in other words, a distance Db remaining in front of the straight traveling vehicle VB until arriving at the intersection CS (hereinafter, referred to as an "intersection arrival distance"). As illustrated in Fig. 13, the intersection arrival distance Db is calculated as the distance from the outer edge of the predicted collision area ACP to the straight traveling vehicle VB.

[0161] In S315, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0162] In S316, the controller 101a calculates the information presentation distance Dth1. The calculation of the information presentation distance Dth1 is based on the vehicle speed VSPb of the straight traveling vehicle VB and the first predetermined deceleration degree DEC1, as defined by the above equation (1).

[0163] In S317, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the information presentation distance Dth1, in other words, whether the straight traveling vehicle VB is located at the information presentation distance Dth1 from the intersection CS or is located at a position closer to the intersection CS than the information presentation distance Dth1. The processing proceeds to S318 in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1, or the information presentation processing is ended in a case where the intersection arrival distance Db is greater than the information presentation distance Dth1.

[0164] In S318, the controller 101a performs the notification issuance for information presentation.

[0165] In the flowchart illustrated in Fig. 7, the controller 101a reads various kinds of control information used for the alarm processing for early notification issuance in S411. The control information read in S411 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0166] In S412, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0167] In S413, the controller 101a determines whether or not the right turning vehicle VA is located inside the predicted collision area ACP is determined. In a case where the right turning vehicle VA is located at the position of the outer edge of the predicted collision area ACP or is located at the position closer to the predicted collision point CPP than the outer edge, the right turning vehicle VA is determined to be located inside the predicted collision area ACP, and the processing proceeds to S414. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the predicted collision point CPP than the outer edge of the predicted collision area ACP, the right turning vehicle VA is determined not to be located inside the predicted collision area ACP, and the alarm processing is ended.

[0168] In S414, the controller 101a calculates the intersection arrival distance Db of the straight traveling vehicle VB.

[0169] In S415, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0170] In S416, the controller 101a calculates the alarm distance Dth2. The calculation of the alarm distance Dth2 is based on the vehicle speed VSPb of the straight traveling vehicle VB and the second predetermined deceleration degree DEC2, as defined by the above equation (2).

[0171] In S417, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the alarm distance Dth2, in other words, whether the straight traveling vehicle VB is located at the alarm distance Dth2 from the intersection CS or is located at a position closer to the intersection CS than the alarm distance Dth2. The processing proceeds to S418 in the case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2, or the alarm processing is ended in a case where the intersection arrival distance Db is greater than the alarm distance Dth2.

[0172] In S418, the controller 101a performs the notification issuance for alarm.

[0173] The procedure illustrated in the flowchart in Fig. 8 differs from the procedure illustrated in the flowchart in Fig. 5 only in the processing that the controller 101a performs in S513. In S513, the controller 101a determines whether or not the right turning vehicle VA has entered the basic intersection area ACSb. In a case where the right turning vehicle VA is located at the position of the outer edge of the basic intersection area ACSb or is located at a position closer to the intersection center CTR than the position, the right turning vehicle VA is determined to have entered the basic intersection area ACSb, and the processing proceeds to S514. In S514, the controller 101a performs the information presentation processing for normal notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 9, and in subsequent S515, the controller 101a performs the alarm processing for normal notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 10. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the intersection center CTR than the outer edge of the basic intersection area ACSb, the right turning vehicle VA is determined not to have entered the basic intersection area ACSb, and this control is ended. The processing that the controller 101a performs in other S511, S512, and S514 to S519 is similar to the processing that the controller 101a performs in S211, S212, and S214 to S219 illustrated in the flowchart in Fig. 5. In S516, the controller 101a determines whether or not the notification issuance has been performed in the information presentation processing or the alarm processing for normal notification issuance. In a case where the notification issuance has been performed, the processing proceeds to S519. On the other hand, in a case where the notification issuance has not been performed, the processing proceeds to S517, and the controller 101a determines whether or not a pedestrian has been detected in the intersection surrounding area AAC. Then, in a case where a pedestrian has been detected, the processing proceeds to S518, and the controller 101a performs the pedestrian caution notification issuance.

[0174] In the flowchart illustrated in Fig. 9, the controller 101a reads various kinds of control information used for the information presentation processing in S611. The control information read in S611 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0175] In S612, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0176] In S613, the controller 101a determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP. The processing proceeds to S614 in a case where the right turning vehicle VA is located outside the predicted collision area ACP, or the information presentation processing is ended in a case where the right turning vehicle VA is not located outside the predicted collision area ACP.

[0177] In S614, the controller 101a reads the vehicle speed VSPa of the right turning vehicle VA.

[0178] In S615, the controller 101a determines whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than a first predetermined vehicle speed Vth1. The processing proceeds to S616 on the assumption that the notification issuance timing for information presentation has arrived in a case where the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, or the information presentation processing is ended in a case where the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1. The first predetermined vehicle speed Vth1 is a vehicle speed set from the viewpoint of whether or not it is possible to secure a time that is long enough to obtain effectiveness of the notification issuance for information presentation, it is possible to secure such a time at the vehicle speed VSPa that is equal to or less than the first predetermined vehicle speed Vth1 while it is not possible to secure such a time at the vehicle speed VSPa exceeding the first predetermined vehicle speed Vth1. Thus, the controller 101a determines that notification issuance for alarm is to be performed in response to arrival of the right turning vehicle VA at the predicted collision area ACP or the approach of the straight traveling vehicle VB to the predicted collision area ACP in the situation. The first predetermined vehicle speed Vth1 is, for example, 20 km / h.

[0179] In this manner, in a case where the right turning vehicle VA has temporarily been stopped at the stop line SL1 before the intersection CS or has sufficiently decelerated before entering the intersection area ACS and has entered the intersection area ACS at the relatively low vehicle speed VSPa, it is determined that the notification issuance timing for information presentation has arrived in response to detection of such a situation, the processing in and after S616 is performed, and whether or not the notification issuance condition is met is determined in the present embodiment. The notification issuance timing for information presentation is not limited thereto, and it is also possible to set the notification issuance timing for information presentation, without limitation based on the driving state such as the vehicle speed VSPa, in response to the fact that the right turning vehicle VA has entered the intersection area ACS, in other words, the fact that the right turning vehicle VA is located in the intersection area ACS.

[0180] In S616, the controller 101a calculates an intersection arrival distance Db of the straight traveling vehicle VB.

[0181] In S617, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0182] In S618, the controller 101a calculates the information presentation distance Dth1.

[0183] In S619, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the information presentation distance Dth1. The processing proceeds to S620 in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1, or the information presentation processing is ended in a case where the intersection arrival distance Db is greater than the information presentation distance Dth1.

[0184] In S620, notification issuance for information presentation is performed.

[0185] In the flowchart illustrated in Fig. 10, the controller 101a reads various kinds of control information used for the alarm processing for normal notification issuance in S711. The control information read in S711 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0186] In S712, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0187] In S713, the controller 101a reads the vehicle speed VSPa of the right turning vehicle VA.

[0188] In S714, the controller 101a determines whether or not the vehicle speed VSPa of the right turning vehicle VA is higher than a second predetermined vehicle speed Vth2. The processing proceeds to S716 in a case where the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2, or the processing proceeds to S715 in a case where the vehicle speed VSPa is equal to or less than the second predetermined vehicle speed Vth2. The second predetermined vehicle speed Vth2 is set to a vehicle speed indicated in a case where the right turning vehicle VA is in a state of traveling at a low speed, for example, in a state of traveling at a reduced speed. The driver of the right turning vehicle VA is determined to be paying sufficient attention to the surrounding situation and other traffic participants when the right turning vehicle VA passes the intersection CS, from the behaviors of the right turning vehicle VA in a case where the vehicle speed VSPa is equal to or less than the second predetermined vehicle speed Vth2. The second predetermined vehicle speed Vth2 is, for example, 5 km / h.

[0189] In S715, the controller 101a reduces the predicted collision area ACP in size. In the present embodiment, the size of the predicted collision area ACP is reduced to the smallest size in the setting and is set to have a diameter that substantially coincides with the lane width W of the straight traveling lane L22 where the straight traveling vehicle VB is traveling.

[0190] In S716, the controller 101a determines whether or not the right turning vehicle VA is located in the predicted collision area ACP. The processing proceeds to S718 in a case where the right turning vehicle VA is located in the predicted collision area ACP, or the processing proceeds to S717 in a case where the right turning vehicle VA is not located in the predicted collision area ACP.

[0191] In S717, the controller 101a determines whether or not the vehicle speed VSPa of the right turning vehicle VA is higher than the first predetermined vehicle speed Vth1. The processing proceeds to S718 in a case where the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1, or the alarm processing is ended in a case where the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1. In a case where the right turning vehicle VA is not located in the predicted collision area ACP and the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, notification issuance for information presentation is performed through information presentation processing (S615 in the flowchart illustrated in Fig. 9).

[0192] In this manner, in a situation in which the right turning vehicle VA has reached the predicted collision area ACP and has already been in the predicted collision area ACP, or the right turning vehicle VA, though being out of the predicted collision area ACP, is traveling at a vehicle speed that is equal to or greater than a specific vehicle speed toward the predicted collision point CPP and is approaching the predicted collision area ACP after entering the intersection area ACS, the controller 101a determines that the notification issuance timing for alarm has arrived in response to detection of such a situation in S714 to S717, performs the processing in and after S718, and determines whether or not the notification issuance condition is met.

[0193] In S718, the controller 101a calculates the intersection arrival distance Db of the straight traveling vehicle V.

[0194] In S719, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0195] In S720, the controller 101a calculates the alarm distance Dth2.

[0196] In S721, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the alarm distance Dth2. The processing proceeds to S722 in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2, or the alarm processing is ended in a case where the intersection arrival distance Db is longer than the alarm distance Dth2.

[0197] In S722, the controller 101a performs the notification issuance for alarm.

[0198] Although the notification issuance for information presentation performed at the time of early notification issuance and the notification issuance for information presentation performed at the time of normal notification issuance can be performed in different manners, they are performed in the similar manner (with the same display and sound, for example) in the present embodiment. The same applies to the notification issuance for alarm, the notification issuance may be performed in the same manner both at the time of the early notification issuance and at the time of normal notification issuance or may be performed in different manners.(Content of notification control in straight traveling vehicle)

[0199] The controller 101b executes the notification control every predetermined time in a case where the intersection CS is detected in a road in front of the host vehicle (that is, the straight traveling vehicle VB). The execution cycles of the notification control may be the same or different between the controller 101a and the controller 101b. Furthermore, both the controllers 101a and 101b can also perform the notification control in a synchronized manner.

[0200] The processes executed by the controller 101a and the controller 101b in relation to the notification control correspond to each other. Thus, the notification control performed by the controller 101b will be described with reference to the flowcharts illustrated in Figs. 4 to 10.

[0201] The controller 101b reads various kinds of control information used for notification control after the notification control is started (S111 illustrated in the flowchart in Fig. 4), detects another vehicle that is present in the right turn lane L11 which is an opposite lane, that is, the right turning vehicle VA (S112), and determines whether or not the right turn intention of the right turning vehicle VA has been detected (S113). In a case where a right turn intention is detected, the controller 101b reads the vehicle speed VSPb of the straight traveling vehicle VB which is a host vehicle, reads the vehicle speed VSPa of the right turning vehicle VA, and sets determination areas (the intersection area ACS and the predicted collision area ACP) on the basis of the vehicle speeds VSPa and VSPb (S116). Similarly to the above description, the controller 101b sets the expanded intersection area ACSe with a relatively large radius φacs in a case where the vehicle speed VSPa is higher than a predetermined vehicle speed, or sets the basic intersection area ACSb with a smaller radius φacs than the relatively large radius φacs in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed. Then, the controller 101b performs the early notification issuance processing (5118) in a case where the expanded intersection area ACSe is set, or performs the normal notification issuance processing (S119) in the other case.

[0202] In the early notification issuance processing, the controller 101b reads various kinds of control information (S211 illustrated in the flowchart in Fig. 5), then specifies the current position Pa of the right turning vehicle VA on the road map (S212), and determines whether or not the right turning vehicle VA has entered the expanded intersection area ACSe (S213). The controller 101b continues the processing and performs the information presentation processing and the alarm processing (S214, S215) in a case where the right turning vehicle VA has entered the expanded intersection area ACSe, or ends this control in a case where the right turning vehicle VA has not entered the expanded intersection area ACSe. Here, in a case where the controller 101b receives a signal indicating that the controller 101a has performed the pedestrian caution notification issuance, the controller 101b performs notification issuance to promote the driver to pay attention to the other vehicle (that is, the right turning vehicle VA). The notification issuance is notification issuance to promote the driver to recognize that the right turning vehicle VA may stop before the crosswalk PC3 after the right turn, that is, in front of the host vehicle in the traveling direction, for example. The information presentation processing and the alarm processing are repeatedly performed until the right turning vehicle VA passes the expanded intersection area ACSe (S219).

[0203] In the information presentation processing for early notification issuance, the controller 101b reads various kinds of control information (S311 illustrated in the flowchart in Fig. 6), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S312). The controller 101b determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP (S313), calculates the intersection arrival distance Db of the straight traveling vehicle VB (S314), calculates the information presentation distance Dth1 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB (S315, S316) in a case where the right turning vehicle VA is determined to be located outside the predicted collision area ACP, and performs the notification issuance for information presentation (S318) in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S317).

[0204] In the alarm processing for early notification issuance, the controller 101b reads various kinds of control information (S411 illustrated in the flowchart in Fig. 7), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map(S412). The controller 101b determines whether or not the right turning vehicle VA is located in the predicted collision area ACP (S413), calculates the intersection arrival distance Db of the straight traveling vehicle VB (S414) and calculates the alarm distance Dth2 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB (S415, S416) in a case where the right turning vehicle VA is determined to be located in the predicted collision area ACP, and performs the notification issuance for alarm (S418) in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S417).

[0205] In the normal notification issuance processing, the controller 101b reads various kinds of control information (S511 illustrated in the flowchart in Fig. 8), then specifies the current position Pa of the right turning vehicle VA on the road map(S512), and determines whether or not the right turning vehicle VA has entered the basic intersection area ACSb (S513). The processing is continued and the information presentation processing and the alarm processing are performed (S514, S515) in a case where the right turning vehicle VA has entered the basic intersection area ACSb, or this control is ended in a case where the right turning vehicle VA has not entered the basic intersection area ACSb. Similarly to the above description, in a case where the controller 101b has received a signal indicating that the controller 101a has performed the pedestrian caution notification issuance, the controller 101b performs notification issuance to promote the driver to pay attention to the other vehicle (that is, the right turning vehicle VA). The information presentation processing and the alarm processing are repeatedly performed until the right turning vehicle VA passes the basic intersection area ACSb (S519).

[0206] In the information presentation processing for normal notification issuance, the controller 101b reads various kinds of control information (S611 illustrated in the flowchart in Fig. 9), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S612). The controller 101b determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP (S613), reads the vehicle speed VSPa of the right turning vehicle VA in a case where the right turning vehicle VA is determined to be located outside the predicted collision area ACP (S614), and determines whether or not the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1 (S615). The controller 101b calculates the intersection arrival distance Db of the straight traveling vehicle VB (S616) and calculates the information presentation distance Dth1 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB (S617, S618) in a case where the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, and performs the notification issuance for information presentation (S620) in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S619).

[0207] In the alarm processing for normal notification issuance, the controller 101b reads various kinds of control information (S711 illustrated in the flowchart in Fig. 10), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S712). The controller 101b reads the vehicle speed VSPa of the right turning vehicle VA (S713), and determines whether or not the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2 (S714). The controller 101b maintains the predicted collision area ACP at a size that has already been set in a case where the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2, or reduces the predicted collision area ACP in size in a case where the vehicle speed VSPa is equal to or less than the second predetermined vehicle speed Vth2 (S715). The intersection arrival distance Db of the straight traveling vehicle VB is calculated (S718) and the alarm distance Dth2 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB is calculated (S719, S720) in a case where the right turning vehicle VA is located in the predicted collision area ACP (S716) or the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1 even if the right turning vehicle VA is located outside the predicted collision area ACP (S717), and the notification issuance for alarm is performed (S722) in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S721).(Description of actions and effects)

[0208] The vehicle notification system 1 according to the present embodiment has the aforementioned configuration. Effects obtained by the present embodiment will be described below.

[0209] Firstly, in a situation where the right turning vehicle VA and the straight traveling vehicle VB face each other with the intersection CS interposed therebetween, the right turn intention of the right turning vehicle VA is detected, notification issuance timings in accordance with the relative positional relationship between the right turning vehicle VA and the intersection CS, that is, the notification issuance timings for information presentation and alarm are then set, and the notification issuance for information presentation or alarm is performed for the traffic participants including the right turning vehicle VA and the straight traveling vehicle VB under the condition that the notification issuance condition defined in regard to the position of the straight traveling vehicle VB is met at these notification issuance timings. This makes it possible to realize notification issuance in an appropriate mode at an appropriate timing in accordance with the degree of urgency of the situation where there is a concern that the right turning vehicle VA and the straight traveling vehicle VB may collide against each other.

[0210] Then, the intersection CS or the predetermined area around the intersection CS, in the present embodiment, the intersection surrounding area AAC is monitored, and in a case where a pedestrian who is a subject of surveillance to be monitored is detected in the intersection surrounding area AAC, notification issuance to promote the right turning vehicle VA to pay attention to the pedestrian, that is, the pedestrian caution notification issuance is performed. It is thus possible to promote the right turning vehicle VA to pay attention to the subject of surveillance that may be present at the intersection CS and the surroundings thereof other than the straight traveling vehicle VB, such as the pedestrian crossing the crosswalk PS3 around the intersection CS, and to avoid contact of the right turning vehicle VA with the subject of surveillance in a situation where attention is likely to be paid to the straight traveling vehicle VB in the opposite lane L22.

[0211] Here, it is possible to avoid contact with the subject of surveillance at the crosswalk PC3 after the right turn, which is likely to occur when the right turning vehicle VA passes the intersection CS, by setting the intersection surrounding area AAC including the crosswalk on the side further forward than the intersection center CTR in the traveling direction of the right turning vehicle VA, that is, the crosswalk PC3 after the right turn as the area where the subject of surveillance or a pedestrian is to be detected.

[0212] Secondly, the intersection area ACS is set, the notification issuance timing is set after the right turning vehicle VA enters the intersection area ACS, the notification issuance for information presentation or alarm is performed under the condition that the straight traveling vehicle VB is located at the notification issuance execution distance Dth1, Dth2 from the intersection CS or is located at a position closer to the intersection CS than the notification issuance execution distance Dth1, Dth2 while the pedestrian caution notification issuance is performed in response to detection of a pedestrian in the intersection surrounding area AAC in a case where the notification issuance condition is not met because the straight traveling vehicle VB is located at a position farther from the intersection CS than the notification issuance execution distance Dth1, Dth2, and it is thus possible to perform the pedestrian caution notification issuance at the timing at which the straight traveling vehicle VB is located at a position far from the intersection CS or the notification issuance for information presentation or alarm at the timing at which the straight traveling vehicle VB approaches the intersection CS, for the right turning vehicle VA that is present in the intersection area ACS.

[0213] In this manner it is possible to switch the mode for the notification issuance in accordance with the position of the straight traveling vehicle VB and to realize notification issuance in an appropriate mode in accordance with the situation for the right turning vehicle VA that is present in the intersection area ACS. Specifically, it is possible to promote the right turning vehicle VA to pay attention to the pedestrian by performing the pedestrian caution notification issuance when the straight traveling vehicle VB is located at a position far from the intersection CS and the degree of urgency of the situation in regard to collision against the right turning vehicle VA is low, and to promote the right turning vehicle VA to recognize that the straight traveling vehicle VB is approaching by switching the mode for notification issuance to the information presentation or the alarm in a case where the straight traveling vehicle VB has approached the intersection CS and the degree of urgency has increased.

[0214] Thirdly, the predicted collision area ACP is set, the pedestrian caution notification issuance is performed using different sound or different sound and display in a case where the right turning vehicle VA is traveling at the vehicle speed VSPa that is higher than the predetermined vehicle speed Vth1 toward the predicted collision point CPP outside the predicted collision area ACP or is located in the predicted collision area ACP and in the other case, and it is thus possible to perform the pedestrian caution notification issuance in a mode in accordance with the degree of urgency of the situation in regard to contact with the subject of surveillance, such as the pedestrian crossing the crosswalk PC3 after the right turn.

[0215] Fourthly, the expanded intersection area ACSe is set in a case where the vehicle speed VSPa of the right turning vehicle VA traveling toward the intersection CS is higher than the predetermined vehicle speed after detection of a right turn intention, the pedestrian caution notification issuance is performed in a case where a pedestrian is detected in the intersection surrounding area AAC after the right turning vehicle VA enters the expanded intersection area ACSe, and it is thus possible to perform the pedestrian caution notification issuance at an earlier timing as compared with a case where the vehicle speed VSPa of the right turning vehicle VA is lower than the predetermined vehicle speed. It is thus possible to promote the right turning vehicle VA traveling toward the intersection CS while maintaining a relatively high vehicle speed to recognize the presence of the pedestrian at an earlier timing and to decelerate sufficiently before the crosswalk PC3 after the right turn.

[0216] Also, it is possible to cause the right turning vehicle VA to temporarily stop before reaching the predicted collision area ACP and to reduce situations where the right turning vehicle VA interrupts passage of the straight traveling vehicle VB by promoting the right turning vehicle VA to decelerate at an earlier timing.

[0217] Furthermore, the notification issuance to promote the straight traveling vehicle VB to pay attention to the right turning vehicle VA is performed in addition to the pedestrian caution notification issuance in a case where a pedestrian is detected in the intersection surrounding area AAC in the present embodiment. In other words, in a case where a pedestrian is detected, the notification issuance to promote attention to the pedestrian is performed for the right turning vehicle VA, while the notification issuance to promote recognition of the presence of the right turning vehicle VA that may stop in front of the crosswalk PC3 after the right turn in response to the execution of the pedestrian caution notification issuance is performed for the straight traveling vehicle VB. This makes it possible not only to avoid contact of the right turning vehicle VA with the pedestrian but also to avoid collision of the straight traveling vehicle VB against the right turning vehicle VA stopped in front of the crosswalk PC3 in response to the pedestrian caution notification issuance.

[0218] In the notification system 1 according to the present embodiment, the notification issuance in the first mode and the notification issuance in the second mode are performed with different sounds via the speaker 141a of the HMI device 131a in the right turning vehicle VA. In other words, the content of notification read in the notification issuance in the first mode and the content of notification read in the notification issuance in the second mode are different from each other. Each of the content of notification in the notification issuance in the first mode and the content of notification in the notification issuance in the second mode is configured of a relatively short sentence, for example. Therefore, the driver of the right turning vehicle VA can understand the content of notification in a short period of time without his / her driving being hindered. In other words, the driver of the right turning vehicle VA can easily identify the notification issuance in the first mode and the notification issuance in the second mode from the difference in sounds, that is, the difference in content of notifications by the sounds. Therefore, the notification system 1 can allow the driver in a situation where the driver is focusing on his / her front side for driving to more accurately recognize, with different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode without hindering the driving.

[0219] Furthermore, in the notification system 1 according to the present embodiment, the notification issuance in the first mode and the notification issuance in the second mode are further performed through different displays in the right turning vehicle VA. As illustrated in Fig. 22, the content of notification displayed in the notification issuance in the first mode is limited to the information indicating the type and the traveling direction (straight traveling direction) of the counterpart vehicle (straight traveling vehicle VB), and as illustrated in Fig. 23, the content of notification displayed in the notification issuance in the second mode is limited to the information PE indicating the presence of the object to be monitored, which are minimum necessary information. Therefore, the notification system 1 can make it easy for the driver of the right turning vehicle VA to easily understand the content of these notifications. Moreover, it is possible to cause the content of the notifications to be displayed by illustration and text with relatively large sizes, for example, by limiting the content of these notifications to minimum necessary information. Therefore, the notification system 1 can improve visibility of the driver by causing the content of the notifications to be displayed by illustration and text with relatively large sizes. In other words, the driver can easily understand the content of the notifications merely by glancing at the display 143a of the HMI device 131a while focusing on the front side. Therefore, the notification system 1 can allow the driver of the right turning vehicle VA to more accurately recognize, on the basis of the different displays in addition to the different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode without hindering the driving.

[0220] In the present embodiment, the notification issuance in the first mode is implemented with different sounds depending on whether the right turning vehicle VA is present in the expanded intersection area ACSe or in the basic intersection area ACSb. In this manner, the driver of the right turning vehicle VA can recognize the straight traveling vehicle VB, which is the target to which attention is to be paid, in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Therefore, the notification system 1 can prompt the driver of the right turning vehicle VA to execute a safer action to avoid collision against the straight traveling vehicle VB at the timing at which the right turning vehicle VA arrives at the intersection CS. Additionally, the driver of the straight traveling vehicle VB can recognize the right turning vehicle VA that is the target to which attention is to be paid in the stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Thus, the notification system 1 can prompt the driver of the straight traveling vehicle VB to execute a safer action to avoid collision against the right turning vehicle VA just in case the right turning vehicle VA tries to turn right at the intersection CS before the straight traveling vehicle VB passes the intersection CS.

[0221] In the notification system 1 according to the present embodiment, the notification issuance in the second mode is performed with different sounds in a case where the right turning vehicle VA is present in the expanded intersection area ACSe and in a case where the right turning vehicle VA is present in the basic intersection area ACSb. In this manner, the driver of the right turning vehicle VA can recognize the object to be monitored that is a target to which attention is to be paid in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Therefore, the notification system 1 can prompt the driver of the right turning vehicle VA to execute a safer action to avoid collision against the target to be monitored at the timing at which the right turning vehicle VA reaches the intersection CS.

[0222] In the notification system 1 according to the present embodiment, the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB are performed with the same sound. Therefore, the notification system 1 can allow the driver of the straight traveling vehicle VB to pay attention only to the right turning vehicle VA to which it is necessary to pay attention even in a case where the object to be monitored to which it is not necessary for the driver of the straight traveling vehicle VB to pay attention to is detected at the intersection CS or in the intersection surrounding area AAC, which is a predetermined area around the intersection CS, when the straight traveling vehicle VB passes the intersection CS. Therefore, the notification system 1 can provide a notification that does not hinder the driving of the driver of the straight traveling vehicle VB.

[0223] In the notification system 1 according to the present embodiment, the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB are performed through the same display in addition to the same sound. Therefore, the notification system 1 can reliably provide a notification that does not hinder the driving of the driver of the straight traveling vehicle VB.

[0224] The notification system 1 according to the present embodiment includes the first notification issuing unit B118a and the third notification issuing unit B122a that perform notification issuance in the fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects an object to be monitored when the notification issuance in the first mode as notification issuance for information presentation is being performed. Furthermore, the notification system 1 includes the second notification issuing unit B119a and the third notification issuing unit B122a that performs the notification issuance in the fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects an object to be monitored when the notification issuance in the first mode as notification issuance for alarm is being performed. Therefore, the notification system 1 can make the driver of the right turning vehicle VA aware of the presence of the pedestrian by the notification issuance in the fourth mode based on the sound and to promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm.

[0225] In the notification system 1 according to the present embodiment, the notification issuance in the fourth mode is further performed through display. Therefore, the notification system 1 can make the driver of the right turning vehicle VA aware of the presence of the pedestrian by the notification issuance in the fourth mode based on the display in addition to the sound and to reliably promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm.

[0226] In the notification system 1 according to the present embodiment, the notification issuance at least with a sound is performed until a predetermined word, a predetermined phrase, or a predetermined sentence representing the content of the notification is read at least once or more in a case where completion of passing of the right turning vehicle VA through the intersection CS is detected on the basis of a result of specification by the road map storage unit B113a when the notification issuance at least with a sound is being performed. Therefore, the notification system 1 can avoid the content of the notification ending in the middle and allow the driver to more accurately understand the content of the notification.(Other embodiments)

[0227] The notification issuance processing may be performed under a condition that the right turning vehicle VA and the straight traveling vehicle VB are in a situation where they face each other with the intersection CS interposed therebetween. Specifically, the execution of the notification issuance processing is avoided in a case where it is expected that the straight traveling vehicle VB passes the intersection CS before the right turning vehicle VA enters the intersection CS or the right turning vehicle VA passes the intersection CS before the straight traveling vehicle VB approaches the intersection CS.

[0228] Fig. 20 illustrates, as an example, a situation where the straight traveling vehicle VB passes the intersection CS before the right turning vehicle VA enters the intersection CS. In the present embodiment, the execution of the notification issuance processing is avoided in a case where the illustrated situation is expected at the timing when the right turn intention of the right turning vehicle VA is detected.

[0229] Specifically, an intersection entry clock time ta1 at which the right turning vehicle VA reaches an intersection entry point P1a in the lane L11 where the right turning vehicle VA is traveling is compared with an intersection exit clock time tb2 at which the straight traveling vehicle VB reaches an intersection exit point P2b in the lane L22 where the straight traveling vehicle VB is traveling, and the execution of the notification issuance processing is avoided in a case where the intersection entry clock time ta1 of the right turning vehicle VA is later than the intersection exit clock time tb2 of the straight traveling vehicle VB. Both the intersection entry point P1a of the right turning vehicle VA and the intersection exit point P2b of the straight traveling vehicle VB can be set on the outer edge of the intersection area ACS (for example, the basic intersection area ACSb), and the intersection entry clock time ta1 can be calculated on the basis of the road map information and the current position Pa and the vehicle speed VSPa of the right turning vehicle VA, while the intersection exit clock time tb2 can be calculated on the basis of the road map information and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0230] In a simplified manner, the intersection entry clock time ta1 of the right turning vehicle VA can be calculated by Equation (6.1) below using a distance Da1 from the current position Pa to the intersection center CTR at the timing (clock time t0) at which the right turn intention is detected and the radius φacs of the intersection area ACS, while the intersection exit clock time tb2 of the straight traveling vehicle VB can be calculated by Equation (6.2) below using a distance Db1 from the current position Pb to the intersection center CTR at the timing at which the right turn intention of the right turning vehicle VA is detected and the radius φacs of the intersection area ACS. ta 1 = t 0 + Da 1 − φacs / VSPa tb 2 = t 0 + Db 1 − φacs / VSPb

[0231] Fig. 21 illustrates, as an example, a situation where the right turning vehicle VA passes the intersection CS before the straight traveling vehicle VB reaches the notification issuance position. In the present embodiment, the execution of the notification issuance processing is avoided in a case where the illustrated situation is expected as well at the timing at which the right turn intention of the right turning vehicle VA is detected, in addition to the situation mentioned earlier.

[0232] Specifically, an intersection leaving clock time ta2 at which the right turning vehicle VA reaches the exit point P2a from the intersection CS is compared with a notification issuance position arrival clock time tb1 at which the straight traveling vehicle VB reaches a point (hereinafter, referred to as a "notification issuance execution point") P1b at a predetermined notification issuance distance from the intersection CS, and the execution of the notification issuance processing is avoided in a case where the notification issuance position arrival clock time tb1 is later than the intersection leaving clock time ta2. The intersection exit point P2a of the right turning vehicle VA can be set on the outer edge of the intersection area ACS (for example, the basic intersection area ACSb), and the notification issuance execution point P1b of the straight traveling vehicle VB can be set at a point at the information presentation distance Dth1 from the intersection CS, for example, a point at the information presentation distance Dth1 from the outer edge of the predicted collision area ACP. The intersection leaving clock time ta2 can be calculated on the basis of the road map information and the current position Pa and the vehicle speed VSPa of the right turning vehicle VA, while the notification issuance position arrival clock time tb1 can be calculated on the basis of the road map information and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0233] In a simplified manner, the intersection leaving clock time ta2 of the right turning vehicle VA can be calculated by Equation (7.1) below using a distance Da1 from the current position Pa to the intersection center CTR at the timing (clock time t0) at which the right turn intention is detected and the radius φacs of the intersection area ACS, while the notification issuance position arrival clock time tb1 of the straight traveling vehicle VB can be calculated by Equation (7.2) below using a distance Db2 from the current position Pb to the predicted collision area ACP at the timing at which the right turn intention of the right turning vehicle VA is detected and the information presentation distance Dth1. ta 2 = t 0 + Da 1 − φacs / VSPa tb 1 = t 0 + Db 2 − Dth 1 / VSPb

[0234] Fig. 19 is a flowchart illustrating an overall flow of notification control according to the present embodiment. In the present embodiment, the notification control can be realized as control that executes the processes illustrated in S811 to S817 in addition to the process illustrated in each step in the flowchart in Fig. 4.

[0235] Differences of a case where the notification control is performed by the controller 101a of the right turning vehicle VA from the flowchart in Fig. 4 will be mainly described. The controller 101a reads various kinds of control information used for the notification control (S111), then detects the straight traveling vehicle VB which is another vehicle in the opposite lane L22 (S112), and if a right turn intention of the right turning vehicle VA which is a host vehicle is detected (S113), the controller 101a calculates the intersection entry clock time ta1 and the intersection leaving clock time ta2 of the right turning vehicle VA in S811.

[0236] In S812, the controller 101a calculates the notification issuance position arrival clock time tb1 and the intersection exit clock time tb2 of the straight traveling vehicle VB.

[0237] In S813, the controller 101a determines whether or not the intersection entry clock time ta1 of the right turning vehicle VA is later than the intersection exit clock time tb2 of the straight traveling vehicle VB. The processing proceeds to S815 in a case where the intersection entry clock time ta1 is later than the intersection exit clock time tb2, or the processing proceeds to S814 in a case where the intersection entry clock time ta1 is before the intersection exit clock time tb2.

[0238] In S814, the controller 101a determines whether or not the notification issuance position arrival clock time tb1 of the straight traveling vehicle VB is later than the intersection leaving clock time ta2 of the right turning vehicle VA. The processing proceeds to S815 in a case where the notification issuance position arrival clock time tb1 is later than the intersection leaving clock time ta2, or the processing illustrated in S114 to S119 surrounded by the frame A of the two-dotted chain line in Fig. 4 is performed in a case where the notification issuance position arrival clock time tb1 is before the intersection leaving clock time ta2.

[0239] In S815, the controller 101a determines whether or not a subject of surveillance to be monitored has been detected at the intersection CS and in the predetermined area around the intersection CS, for example, whether a pedestrian has been detected in the intersection surrounding area AAC. The processing proceeds to S816 in a case where a pedestrian has been detected, or this control is ended in a case where no pedestrians have been detected.

[0240] In S816, the controller 101a performs notification issuance to promote the right turning vehicle VA to pay attention to the pedestrian, that is, pedestrian caution notification issuance.

[0241] In S817, the controller 101a notifies the straight traveling vehicle VB of the fact that the pedestrian caution notification issuance has been performed for the right turning vehicle VA. This promotes the straight traveling vehicle VB to recognize that the right turning vehicle VA that may stop before the crosswalk PC3 after the right turn in response to the execution of the pedestrian caution notification issuance is present in a situation where the execution of the notification issuance processing in the processes in S114 to S119 illustrated in the flowchart in Fig. 4 is avoided.

[0242] In this manner, although the execution of the notification issuance processing leads to an increase in computational loads on the controllers 101a and 101b required for the monitoring of the right turning vehicle VA and the straight traveling vehicle VB (tracking of the current positions Pa and Pb and the like), it is possible to reduce unnecessary execution of the notification issuance processing and an accompanying increase in computational loads and to effectively use the computational capacities of the controllers 101a and 101b by allocating a generated margin to other control, by avoiding the execution of the notification issuance processing in a case where the right turning vehicle VA and the straight traveling vehicle VB are not in a situation where they face each other with the intersection CS interposed therebetween.

[0243] Also, the intersection leaving clock time ta2 of the right turning vehicle VA and the notification issuance position arrival clock time tb1 of the straight traveling vehicle VB are predicted, the pedestrian caution notification issuance is performed for the right turning vehicle VA in response to detection of a pedestrian in the intersection surrounding area AAC and the straight traveling vehicle VB is notified of the fact that the pedestrian caution notification issuance has been performed for the right turning vehicle VA in a case where the notification issuance position arrival clock time tb1 is later than the intersection leaving clock time ta2, and it is thus possible to cause the straight traveling vehicle VB to recognize the presence of the right turning vehicle VA that may stop before the crosswalk PC3 after the right turn in response to the execution of the pedestrian caution notification issuance and to reduce situations where the straight traveling vehicle VB collides against the right turning vehicle VA.

[0244] In the above description, the pedestrian caution notification issuance is performed after the right turning vehicle VA enters the intersection area ACS (the expanded intersection area ACSe, the basic intersection area ACSb). The pedestrian caution notification issuance can also be performed before the right turning vehicle VA enters the intersection area ACS. Fig. 18 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at a timing at which the pedestrian caution notification issuance is performed as an example of such a case.

[0245] As illustrated in Fig. 18, the pedestrian caution notification issuance can also be performed at a timing before the right turning vehicle VA reaches the intersection area ACS. For example, the controller 101a performs the pedestrian caution notification issuance without waiting for the entry to the intersection area ACS in a case where a pedestrian is detected in the intersection surrounding area AAC by a signal from a smartphone that the pedestrian has after the right turning vehicle VA displays its intention to turn right at the intersection CS by operating a right turn signal or entering a right turn only lane.

[0246] In this manner, the notification issuance timing is set after the right turning vehicle VA enters the intersection area ACS, the notification issuance for information presentation or alarm is performed when the notification issuance condition in regard to the position of the straight traveling vehicle VB is met while the pedestrian caution notification issuance is performed at a timing before the right turning vehicle VA enters the intersection area ACS, and it is thus possible to cause the right turning vehicle VA to pay attention to the pedestrian before entering the intersection area ACS and to promote the right turning vehicle VA to decelerate at an early timing before or after the entry to the intersection area ACS and temporarily stop at or near the position of the entry to the intersection CS. This makes it possible to more reliably avoid contact of the right turning vehicle VA with the pedestrian and to further reduce situations where the right turning vehicle VA interrupts passage of the straight traveling vehicle VB by the right turning vehicle VA stopping before the crosswalk PC3 after the right turn.

[0247] In the above description, the distance from the outer edge of the predicted collision area ACP, specifically, the intersecting point between the traveling path TRb of the straight traveling vehicle VB and the circle (the circles illustrated by the dashed lines in the drawings) defining the outer edge of the predicted collision area ACP to the straight traveling vehicle VB is employed as the distance Db from the intersection CS to the straight traveling vehicle VB. The distance Db is not limited thereto, and the distance from the predicted collision point CPP to the straight traveling vehicle VB may be employed, or the distance along the center line of the opposite lane L22 from the right turning vehicle VA to the straight traveling vehicle VB may be employed, as the distance Db.

[0248] Although the controllers 101a and 101b included in the right turning vehicle VA and the straight traveling vehicle VB, respectively constitute the calculation unit of the notification system 1 and the controllers 101a and 101b constitute one virtual controller, a configuration in which roadside equipment or a remote server is caused to have the road map and a computer program for the notification control and is caused to perform the notification control outside the vehicles may also be adopted. In this case, the right turning vehicle VA and the straight traveling vehicle VB transmit position information of the respective vehicles to the external controller through road-to-vehicle communication and receive command signals which are results of calculation related to control. Then, the notification issuance for the information presentation or the alarm is executed on the basis of the command signals.

[0249] The traffic participants as targets of the notification issuance are not limited to the right turning vehicle VA and the straight traveling vehicle VB and may be any other vehicles that are approaching the intersection CS. It is possible to exemplify, as such vehicles, a vehicle traveling toward the intersection CS (that is, a crossing vehicle) in a lane other than the right turn lane L11 and lanes extending in parallel to the right turn lane L11 (for example, the straight traveling lane L12), specifically, a crossing lane L31 intersecting the right turn lane L11 from among lanes leading to the intersection CS to which the right turning vehicle VA is directed. Here, a vehicle other than the right turning vehicle VA that is approaching the intersection CS and may potentially enter the intersection CS is referred to as an "intersection entering vehicle". The intersection entering vehicle may include not only the straight traveling vehicle VB but also a crossing vehicle.

[0250] In the road illustrated in Figure 12, in a case where a crossing vehicle (not shown) is present in addition to or instead of the straight traveling vehicle VB as an intersection entering vehicle, and when there is no traffic signal installed at the intersection CS to regulate the movement of the crossing vehicle, there is a concern that the timing of the crossing vehicle entering the intersection CS may coincide with that of the right turning vehicle VA, potentially resulting in contact or collision between these vehicles.

[0251] In such a situation, the notification system 1 monitors the relative positional relationship between the right turning vehicle VA and the crossing vehicle after detecting the right turn intention of the right turning vehicle VA, and similarly to the above description, the notification issuance in accordance with urgency of the situation related to contact or collision between the right turning vehicle VA and the crossing vehicle is executed at an appropriate timing before the right turning vehicle VA passes the intersection CS after approaching the intersection CS. As an example, the right turning vehicle VA and the crossing vehicle perform information presentation processing and alarm processing similar to those that the right turning vehicle VA and the straight traveling vehicle VB execute between these vehicle VA and VB.

[0252] The intersection surrounding area AAC is monitored, and when a subject of surveillance such as a pedestrian is detected in the intersection surrounding area AAC, a notification issuance to promote attention to the subject of surveillance or the right turning vehicle VA is performed for the crossing vehicle. This enables the crossing vehicle to recognize the presence of a pedestrian at the crosswalk PC3 after the right turn, and encourages the crossing vehicle to decelerate before entering the intersection CS. Consequently, it is possible to prevent situations in which the right turning vehicle VA is promoted to temporarily stop before the crosswalk PC3 by the notification issuance to call for attention and obstruct the path of the host vehicle, or the crossing vehicle, and contact or collision occurs between these vehicles.

[0253] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.REFERENCE SIGNS LIST

[0254] 1vehicle notification system 101a, 101bcontroller 111a, 111bposition sensor 112a, 112bvehicle speed sensor 113a, 113bright turn signal switch 121a, 121btransmitter 122a, 122breceiver 131a, 131bhuman machine interface device (HMI device) VAright turning vehicle VBstraight traveling vehicle ACSintersection area ACPpredicted collision area AACintersection surrounding area

Examples

Embodiment Construction

[0013]Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same reference signs are given to identical or equivalent components in each figure.

(Overall Configuration of Vehicle Notification System)

[0014]Fig. 1 is a schematic diagram illustrating a configuration of a vehicle notification system (hereinafter, simply referred to as a "notification system" in some cases) 1 according to an embodiment of the present invention.

[0015]In the present embodiment, a traffic situation where a vehicle (hereinafter, referred to as a "right turning vehicle") VA traveling toward an intersection on a left-hand traffic road and another vehicle (hereinafter, referred to as a "straight traveling vehicle") VB traveling in a straight direction toward the intersection in a lane (hereinafter, referred to as an "opposite lane" in some cases) opposite to a lane (hereinafter, referred to as a "traveling lane" in some cases) in which the right turning...

BACKGROUND OF THE INVENTIONField of the Invention

[0001] Embodiments of the present invention relate to a vehicle notification system.Description of the Related Art

[0002] For the purpose of assisting driving in situations where right turn is made at intersections on left-hand traffic roads, there is a technology of recognizing operation statuses of other traffic participants including oncoming vehicles moving straight ahead toward intersections in opposite lanes and providing an instruction for a right turn timing that allows a driver to avoid collisions against the oncoming vehicles to the driver.

[0003] Here, detection of traffic participants is typically performed by in-vehicle sensors such as cameras or radars.

[0004] [Patent Document 1] JP 2009-265832 A

[0005] However, it is difficult for in-vehicle sensors to detect traffic participants who are present at blind angles such as behind obstacles.

[0006] Specifically, in a case where there is another vehicle traveling side by side with an oncoming vehicle in the same lane, or in a case where another vehicle is stopping to wait for turning right in front of the oncoming vehicle, the vehicle may become an obstacle, and the oncoming vehicle may be present at a blind angle of the vehicle, which may make it difficult to detect the oncoming vehicle depending on an in-vehicle sensor equipped in the right turning vehicle.

[0007] In a case where the vehicle that may become an obstacle is a large vehicle, the blind angle becomes wider, which makes it more difficult to detect the oncoming vehicle.

[0008] In driving assistance, notifications are implemented to inform drivers of occurrence of various events. Types of notifications for the drivers include, for example, auditory notifications by sound and / or voice using speakers, visual notifications through display of text and / or illustration on displays, and tactile notifications by vibrations of steering wheels. It is desirable that notifications do not hinder driving of a driver and make it easy for the driver to know a target to which attention is to be paid.SUMMARY OF THE INVENTION

[0009] Thus, an object of the present invention is to provide a vehicle notification system capable of providing a notification that does not hinder driving of a driver and makes it easy for the driver to know a target to which attention is to be paid and contributing to a further improvement in traffic safety.

[0010] To solve the above-mentioned problem, a vehicle notification system according to one aspect of the present invention performs notification issuance at least with sounds for traffic participants including a first vehicle that is present in a traveling lane leading to an intersection to turn right or left at the intersection and a second vehicle that travels in a straight traveling direction toward the intersection in a lane opposite to the traveling lane. The vehicle notification system includes: a monitored object detection unit that detects an object to be monitored that is movable in a sidewalk at the intersection or in a predetermined area around the intersection; a first notification issuing unit that performs notification issuance in a first mode to avoid collision between the first vehicle and the second vehicle; and a second notification issuing unit that performs notification issuance in a second mode for the first vehicle to avoid collision between the frist vehicle and the object to be monitored that has been detected by the monitored object detection unit. The notification issuance in the first mode and the notification issuance in the second mode are performed with mutually different sounds in the first vehicle.EFFECTS OF THE INVENTION

[0011] According to one aspect of the present invention, it is possible to provide a vehicle notification system capable of providing a notification that does not hinder driving of a driver and makes it easy for the driver to know a target to which attention is to be paid and contributing to a further improvement in traffic safety.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 is a schematic diagram illustrating an overall configuration of a vehicle notification system according to an embodiment of the present embodiment; Fig. 2 is a schematic diagram illustrating an internal configuration of a controller included in a right turning vehicle; Fig. 3 is a schematic diagram illustrating an internal configuration of a controller included in a straight traveling vehicle; Fig. 4 is a flowchart illustrating an overall flow of notification control; Fig. 5 is a flowchart illustrating content of early notification issuance processing; Fig. 6 is a flowchart illustrating content of the early notification issuance processing (information presentation processing); Fig. 7 is a flowchart illustrating content of the early notification issuance processing (alarm processing); Fig. 8 is a flowchart illustrating content of normal notification issuance processing; Fig. 9 is a flowchart illustrating content of the normal notification issuance processing (information presentation processing); Fig. 10 is a flowchart illustrating content of the normal notification issuance processing (alarm processing); Fig. 11 is an explanatory diagram illustrating a method of calculating an information presentation distance and an alarm distance; Fig. 12 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a target of a notification; Fig. 13 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at a notification issuance timing for information presentation; Fig. 14 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at a notification issuance timing for alarm; Fig. 15 is a schematic diagram illustrating the configuration of determination areas when the intersection area is expanded; Fig. 16 is a schematic diagram illustrating the configuration of determination areas when the predicted collision area is reduced; Fig. 17 is a schematic diagram showing the timing of detection of a subject of surveillance and the corresponding notification issuance after a right turning vehicle has entered the intersection area; Fig. 18 a schematic diagram showing the timing of detection of a subject of surveillance and the corresponding notification issuance before a right turning vehicle reaches the intersection area; Fig. 19 is a flowchart illustrating an overall flow of notification control according to another embodiment of the present invention; Fig. 20 is a schematic diagram showing a situation in which a straight traveling vehicle passes through the intersection before a right turning vehicle enters the intersection; Fig. 21 is a schematic diagram showing a situation in which a right turning vehicle passes through the intersection before a straight traveling vehicle reaches the notification issuance position; Fig. 22 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the right turning vehicle; Fig. 23 is a schematic diagram illustrating an example of the notification issuance in the second mode through display in the notification control performed in the right turning vehicle; Fig. 24 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the straight traveling vehicle; and Fig. 25 is a schematic diagram illustrating an example of the notification issuance in the fourth mode through display in notification control performed in the right turning vehicle. DETAILED DESCRIPTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same reference signs are given to identical or equivalent components in each figure.(Overall Configuration of Vehicle Notification System)

[0014] Fig. 1 is a schematic diagram illustrating a configuration of a vehicle notification system (hereinafter, simply referred to as a "notification system" in some cases) 1 according to an embodiment of the present invention.

[0015] In the present embodiment, a traffic situation where a vehicle (hereinafter, referred to as a "right turning vehicle") VA traveling toward an intersection on a left-hand traffic road and another vehicle (hereinafter, referred to as a "straight traveling vehicle") VB traveling in a straight direction toward the intersection in a lane (hereinafter, referred to as an "opposite lane" in some cases) opposite to a lane (hereinafter, referred to as a "traveling lane" in some cases) in which the right turning vehicle VA is traveling are present is assumed. The notification system 1 can be applied not only to left-hand traffic roads but also to right-hand traffic roads. In a case of right-hand traffic, a traffic situation where a left turning vehicle traveling toward an intersection and a straight traveling vehicle traveling toward the intersection in an opposite lane are present is a target. In other words, the notification system 1 can be applied to traffic situations where a right or left turning vehicle (hereinafter, referred to as a "right or left turning vehicle" or a "non-straight traveling vehicle") in a traveling lane and a straight traveling vehicle in an opposite lane are present together. In a case of left-hand traffic, the right turning vehicle is a vehicle turning right at the intersection and should not hinder the straight traveling vehicle traveling in the opposite lane from passing the intersection.

[0016] The notification system 1 includes, as main elements related to the present embodiment, auxiliary devices such as vehicle sensors 111 to 113, communication devices 121 and 122, and a human machine interface (HMI) device 131 in addition to a controller 101.

[0017] In the present embodiment, various elements including the controller 101 are provided in each of the right turning vehicle VA and the straight traveling vehicle VB. A controller 101a included in the right turning vehicle VA and a controller 101b included in the straight traveling vehicle VB configure one virtual controller constituting the notification system 1 through mutual cooperation. It is a matter of course that the notification system 1 can be configured as an in-vehicle system for the right turning vehicle VA by the controller 101a included in the right turning vehicle VA and the auxiliary devices thereof and can also be configured as an in-vehicle system for the straight traveling vehicle VB by the controller 101b included in the straight traveling vehicle VB and the auxiliary devices thereof.

[0018] In the following description, vehicle-to-vehicle communication is performed between the right turning vehicle VA and the straight traveling vehicle VB to allow vehicle information related to the right turning vehicle VA to be shared between the right turning vehicle VA and the straight traveling vehicle VB and allow vehicle information related to the straight traveling vehicle VB to be shared between both the vehicles VA and VB. In the present embodiment, the vehicle information to be communicated or shared between the right turning vehicle VA and the straight traveling vehicle VB includes current positions Pa and Pb, vehicle speeds VSPa and VSPb, operating statuses of right turn signals (that is, outputs of right turn signal switches), and lane IDs of the vehicles VA and VB. Furthermore, the vehicle information may include a type of each of the vehicles VA and VB. The communication between the right turning vehicle VA and the straight traveling vehicle VB is not limited to direct communication via vehicle-to-vehicle communication and may also be performed indirectly through roadside equipment installed at roadsides, servers disposed remotely, communication devices included in vehicles other than the right turning vehicle VA and the straight traveling vehicle VB. Hereinafter, vehicle information related to the right turning vehicle VA may be referred to as right turning vehicle information, and vehicle information related to the straight traveling vehicle VB may be referred to as straight traveling vehicle information. In the present embodiment, the types of the vehicles VA and VB in the vehicle information to be communicated or shared between the right turning vehicle VA and the straight traveling vehicle VB means which of a two-wheeled vehicle or a four-wheeled vehicle each of the right turning vehicle VA and the straight traveling vehicle VB is. The two-wheeled vehicle refers to a motorcycle.

[0019] In the present embodiment, the right turning vehicle VA and the straight traveling vehicle VB constitute the notification system 1 with similar basic configurations. The right turning vehicle VA includes the controller 101a and also includes vehicle sensors 111a, 112a, and 113a, communication devices 121a and 122a, and an HMI device 131a. On the other hand, the straight traveling vehicle VB includes the controller 101b and also includes vehicle sensors 111b, 112b, and 113b, communication devices 121b and 122b, and an HMI device 131b.

[0020] The controllers 101a and 101b constitute a calculation unit of the notification system 1 and generate and output a command signal in accordance with results of calculation. The controllers 101a and 101b are configured of microcomputers including central processing units (CPUs), storage devices such as ROMs and RAMs, and input / output interfaces.

[0021] The vehicle sensors 111a to 113a and 111b to 113b constitute a detection unit of the notification system 1. The right turning vehicle VA includes a position sensor 111a, a vehicle speed sensor 112a, and a right turn signal switch 113a as the accompanying vehicle sensors, while the straight traveling vehicle VB includes a position sensor 111b, a vehicle speed sensor 112b, and a right turn signal switch 113b as the accompanying vehicle sensors.

[0022] The position sensor 111a detects the current position Pa of the right turning vehicle VA, and the position sensor 111b detects the current position Pb of the straight traveling vehicle VB. Both the position sensors 111a and 111b can be configured of global navigation satellite system (GNSS) receivers and detect the current positions of the target vehicles VA and VB with latitude and longitude coordinates Pa (Pai, Paj) and Pb (Pbi, Pbj).

[0023] The vehicle speed sensor 112a detects the traveling speed (hereinafter, referred to as a "vehicle speed") VSPa of the right turning vehicle VA, while the vehicle speed sensor 112b detects the vehicle speed VSPb of the straight traveling vehicle VB. The vehicle speed sensors 112a and 112b can perform the detection by detecting wheel speeds (for example, rotation speeds of driven wheels) of the target vehicles VA and VB and converting the wheel speeds into traveling distances per unit time using tire dynamic radii or the like.

[0024] The right turn signal switch 113a outputs an on signal when a right direction indicator (hereinafter, referred to as a "right turn signal") included in the right turning vehicle VA is activated, and the right turn signal switch 113b outputs an on signal when the right turn signal included in the straight traveling vehicle VB is activated. The operations of the right turn signal switches 113a and 113b indicate that the target vehicles VA and VB intend to turn right on the road or change lanes.

[0025] Detection signals from the position sensor 111a, the vehicle speed sensor 112a, and the right turn signal switch 113a are output to the controller 101a, while detection signals from the position sensor 111b, the vehicle speed sensor 112b, and the right turn signal switch 113b are output to the controller 101b.

[0026] The HMI devices 131a and 131b constitute an output unit of the notification system 1. The HMI device 131a receives a command signal from the controller 101a and provides a notification related to a traffic situation to a driver of the right turning vehicle VA. The HMI device 131b receives a command signal from the controller 101b and provides a notification related to the traffic situation to a driver of the straight traveling vehicle VB.

[0027] Notifications by the HMI devices 131a and 131b are at least auditorily performed. The notifications by the HMI devices 131a and 131b are not limited thereto and may include, in addition to auditory notifications, visual notifications. In other words, the notification system 1 can issue notifications through sound via the HMI devices 131a and 131b, and can also issue notifications both through sound and through display. The HMI devices 131a and 131b are disposed at locations that allow the drivers to easily view the HMI devices 131a and 131b, such as on dashboards in the vehicles. Note that in the present embodiment, the notification through sound includes notifications through alert sounds such as buzzer sounds, beeps, and electronic sounds, or notifications through voice guidance based on recorded human voices or on machine-generated voices.

[0028] Moreover, the HMI devices 131a and 131b include, for example, speakers 141a and 141b as audio output units, and displays 143a and 143b as display units. The speakers 141a and 141b convey content of notifications to the driver by sound. This enables auditory notifications. Moreover, the displays 143a and 143b display content of notifications to the driver at least by illustration. The content of the notifications on the displays 143a and 143b may include texts. This enables visual notifications. Additionally, the HMI devices 131a and 131b further include touch panels, switches, and keys, which are not illustrated in the drawings.

[0029] The right turning vehicle VA includes a transmitter 121a and a receiver 122a, while the straight traveling vehicle VB includes a transmitter 121b and a receiver 122b. The transmitter 121a and the receiver 122a included in the right turning vehicle VA constitute a vehicle-to-vehicle communication device of the right turning vehicle VA, while the transmitter 121b and the receiver 122b included in the straight traveling vehicle VB constitute a vehicle-to-vehicle communication device of the straight traveling vehicle VB. The right turning vehicle VA and the straight traveling vehicle VB can perform wireless communication via the mutual vehicle-to-vehicle communication devices.

[0030] As mentioned earlier, the communication between the right turning vehicle VA and the straight traveling vehicle VB is not limited to direct communication between the right turning vehicle VA and the straight traveling vehicle VB and may also be indirect communication via roadside equipment, remote servers, other vehicles, or the like.

[0031] Moreover, when the right turning vehicle VA passes the intersection, the right turning vehicle VA monitors the intersection or a predetermined area around the intersection, and in a case where a pedestrian or another subject of surveillance to be monitored is detected in the predetermined area, notification issuance to promote the right turning vehicle (specifically, the driver thereof) to pay attention to the subject of surveillance is performs at least through sound via the HMI device 131a. The driver of the right turning vehicle VA can pay attention to the subject of surveillance by the activation of the HMI device 131a and recognize presence of the subject of surveillance in a case where the subject of surveillance is present in the predetermined area.

[0032] In the present embodiment, the subject of surveillance to be monitored refers to an individual or a person who is legally permitted to move or travel along a sidewalk, such as a pedestrian or a mobility scooter passenger. Also, an area on the side further forward than the center of the intersection (hereinafter, referred to as an "intersection center") with respect to the traveling direction of the right turning vehicle VA passing the intersection, that is an area including a crosswalk provided on the road after the right turn (hereinafter, referred to as a "crosswalk after the right turn" in some cases) is set as an "intersection surrounding area", and the intersection surrounding area is regarded as a target to be monitored.

[0033] The controller 101a of the right turning vehicle VA is capable of communicating with a mobile communication device 201 held by the subject of surveillance. The mobile communication device 201 in a case where the subject of surveillance is a pedestrian is, for example, a mobile terminal such as a smartphone, and the mobile communication device 201 in a case where the subject of surveillance is a mobility scooter passenger is, for example, an in-vehicle communication device included in the mobility scooter. The controller 101a detects the position of the subject of surveillance on the basis of a signal transmitted from the mobile communication device 201 and detects the subject of surveillance in the intersection surrounding area by the position of the subject of surveillance being located in the intersection surrounding area.

[0034] The communication between the controller 101a and the mobile communication device 201 may be unidirectional communication from the mobile communication device 201 to the controller 101a or may be bidirectional communication therebetween. In a case where the communication is bidirectional, it is possible to notify the subject of surveillance of the presence of the right turning vehicle VA that has detected the subject of surveillance and promote the subject of surveillance to pay attention to the right turning vehicle VA. For example, voice guidance may be performed via a smartphone, which is the mobile communication device 201, to let the subject of surveillance know the presence and approach of the right turning vehicle VA.

[0035] Furthermore, the communication between the controller 101a and the mobile communication device 201 may be direct or indirect. The controller 101a and the mobile communication device 201 can communicate unidirectionally or bidirectionally via a traffic signal SG (specifically, a communication terminal included in the signal SG) installed by the crosswalk, for example.

[0036] The detection of the subject of surveillance can be performed not only by the mobile communication device 201 but also by a surveillance camera installed to be able to monitor the intersection surrounding area. Specifically, an image acquired by the surveillance camera is analyzed, and a signal indicating that the subject of surveillance has been detected is sent from the surveillance camera to the controller 101a in a case where the subject of surveillance is detected in the intersection surrounding area.

[0037] Fig. 12 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a notification target according to the present embodiment.

[0038] In the present embodiment, a traffic situation in which the right turning vehicle VA and the straight traveling vehicle VB face each other with an intersection CS interposed therebetween is assumed. The intersection (a cross intersection in the present embodiment) CS is present on a road R with two lanes on each side including right turn lanes L11 and L21 and straight lanes L12 and L22. The right turning vehicle VA is present in the right turn lane L11 on one side and is approaching the intersection CS, while the straight traveling vehicle VB is present in the straight lane L22 on the other side and is traveling at a position separated from the intersection CS in a straight direction toward the intersection CS. Here, the right turn lane L11 corresponds to the traveling lane of the right turning vehicle VA, and the right turn lane L21 and the straight lane L22 correspond to lanes opposite to the right turning vehicle VA. The right turn lane L21 and the straight lane L22 as the opposite lanes may be referred to as an "opposite right turn lane" and an "opposite straight lane" below.

[0039] On the road R, a crosswalk PC1 is provided in front of the intersection CS for the right turn lane L11 and the straight traveling lane L12, and a crosswalk PC2 is provided in front of the intersection CS for the opposite right turn lane L21 and the opposite straight traveling lane L22. Furthermore, a crosswalk (that is, a crosswalk after the right turn) PC3 is provided on the road after the right turn of the right turning vehicle VA, and a crosswalk PC4 is provided on the road on the side opposite to the road after the right turn with the intersection CS interposed therebetween. A stop line SL1 is provided at front ends of the right turn lane L11 and the straight traveling lane L12 near the intersection CS, and a stop line SL2 is provided at front ends of the opposite right turn lane L21 and the opposite straight traveling lane L22 near the intersection CS. Similarly, stop lines SL3 and SL4 are provided in front of the crosswalks PC3 and PC4, respectively, on the roads leading to the intersection CS other than the above roads in a state where the intersection CS is seen in front.

[0040] In the present embodiment, the area including the crosswalk PC3 after the right turn and its surroundings is set as an "intersection surrounding area" AAC. Fig. 12 schematically illustrates the intersection surrounding area AAC by a dashed line frame. The intersection surrounding area AAC includes, in the "intersection surroundings", regions before and after the crosswalk PC3 in a length direction and regions on both sides of the crosswalk PC3 in the direction perpendicular to the length direction on the assumption that a moving direction when the crosswalk PC3 is crossed is the length direction of the crosswalk PC3. In other words, in the present embodiment, the intersection surrounding area AAC is an area obtained by expanding the crosswalk PC3 in the four directions, namely the front, rear, left, and right directions. The intersection surrounding area AAC can be appropriately set as an area where a subject of surveillance to be monitored such as a pedestrian may be present and can be set in an appropriate shape such as an ellipse or an oval, as well as the rectangle illustrated in Fig. 12.

[0041] In addition to the right turning vehicle VA and the straight traveling vehicle VB, a vehicle (hereinafter, referred to as a "waiting vehicle") VC stopping to wait for turning right is present before a stop line SL2 in front of the straight traveling vehicle VB in the opposite right turn lane L21. In the illustrated traffic situation, the waiting vehicle VC is a visual obstacle blocking a part of a view from the right turning vehicle VA and blocking a part of a view from the straight traveling vehicle VB. In this situation, it is difficult to visually recognize the straight traveling vehicle VB from the right turning vehicle VA due to the straight traveling vehicle VB being present at a blind angle of the waiting vehicle VC seen from the right turning vehicle VA, and it is difficult to visually recognize the right turning vehicle VA from the straight traveling vehicle VB due to the right turning vehicle VA being present at a blind angle of the waiting vehicle VC seen from the straight traveling vehicle VB.

[0042] In such a situation, the notification system 1 monitors a relative positional relationship between the right turning vehicle VA and the straight traveling vehicle VB after the right turning vehicle VA displays its intention to turn right. Then, the notification system 1 issues a notification in accordance with a degree of urgency of circumstances related to collision between the right turning vehicle VA and the straight traveling vehicle VB at an appropriate timing after the right turning vehicle VA approaches the intersection CS and before the right turning vehicle VA passes the intersection CS. Note that in the present embodiment, the notification system 1 ends the notification issuance at a timing at which the right turning vehicle VA has passed the intersection CS.

[0043] In conjunction with this, the notification system 1 performs notification issuance to promote the right turning vehicle VA to pay attention to the subject of surveillance in a case where the subject of surveillance, for example, a pedestrian crossing the crosswalk PC3 is detected in the intersection surrounding area AAC. In the following description, a case where a pedestrian is assumed to be a subject of surveillance will be exemplified.(Internal Configuration of Controller)

[0044] Fig. 2 is a schematic diagram illustrating an internal configuration of the controller 101a included in the right turning vehicle VA, and Fig. 3 is a schematic diagram illustrating an internal configuration of the controller 101b included in the straight traveling vehicle VB. The internal configuration of each of the controllers 101a and 101b will be described in turn on the basis of Figs. 2 and 3 and with reference to Fig. 12 as needed.

[0045] As illustrated in Fig. 2, the controller 101a includes a host vehicle position detection unit B111a, an other vehicle position detection unit B112a, a road map storage unit B113a, a right turn intention detection unit B114a, a driving state detection unit B115a, a first notification issuance timing setting unit B116a, a second notification issuance timing setting unit B117a, a first notification issuing unit B118a, a second notification issuing unit B119a, a determination area setting unit B120a, a pedestrian detection unit B121a and a third notification issuing unit B122a. A function of each of these units B111a to B122a is realized in a software manner by the central processing unit included in the controller 101a reading a computer program stored in the storage device and operating in accordance with instructions of the program.

[0046] Note that data held by each of the components B111a to B122a and results of processing performed by each of the components B111a to B122a can be mutually referenced among the components B111a to B122a regardless of the presence or absence of arrows indicating a data flow inside the controller 101a in Fig. 2. The data held by each of the components B111a to B122a includes detection signals from the vehicle sensors 111a, 112a, and 113a output to the controller 101a, and vehicle information acquired from the straight traveling vehicle VB via the receiver 122a. These premises in the controller 101a are also applicable to the controller 101b of the straight traveling vehicle VB.

[0047] The host vehicle position detection unit B111a detects the current position Pa of the right turning vehicle VA, which is a host vehicle. The detection of the current position Pa performed by the host vehicle position detection unit B111a is based on an output signal from the position sensor 111a included in the right turning vehicle VA.

[0048] The other vehicle position detection unit B112a detects the current position Pb of the straight traveling vehicle VB, which is another vehicle. The detection of the current positions Pb performed by the other vehicle position detection unit B112a is performed by reading position information indicating the current position Pb from vehicle information acquired from the straight traveling vehicle VB via the receiver 122a included in the right turning vehicle VA.

[0049] The road map storage unit B113a stores a road map. In the present embodiment, the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB are coordinates of latitudes and longitudes indicating these positions Pa and Pb. The road map storage unit B113a extracts a map of a range or a section including the intersection CS and its surroundings in the road map and specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map. In the road map, identifiers (hereinafter, referred to as "link IDs") corresponding to lanes leading to the intersection CS, such as the right turn lanes L11 and L21 and the straight lanes L12 and L22, are assigned and are stored in association with the corresponding lanes L11, L21, L12 and L22. It is possible to distinguish the lane in which a target vehicle is present or is traveling by specifying the position on the road map. Furthermore, in the road map, the intersection surrounding area AAC is defined by specifying the coordinates on the road map corresponding to the locations included within it.

[0050] The right turn intention detection unit B114a detects that the right turning vehicle VA has a right turn intention. The right turn intention detection by the right turn intention detection unit B114a can be performed with an output signal from the right turn signal switch 113a included in the right turning vehicle VA, and in a case where the right turn lane L11 is a lane only for right turn, the detection can also be performed by reading the link ID associated with the lane where the vehicle is traveling from the road map and detecting that the right turning vehicle VA is present in the right turn lane L11.

[0051] The driving state detection unit B115a detects the vehicle speed VSPb of the straight traveling vehicle VB. The driving state detection unit B115a detects the vehicle speed VSPb by reading vehicle speed information indicating the vehicle speed VSPb from the vehicle information acquired from the straight traveling vehicle VB via the receiver 122a included in the right turning vehicle VA.

[0052] The first notification issuance timing setting unit B116a detects that the right turning vehicle VA is present at a predetermined position relative to the intersection CS, specifically, that the right turning vehicle VA is at a predetermined distance from the center position CTR (hereinafter, referred to as an "intersection center") of the intersection CS or at a position closer to the intersection center CTR than the predetermined distance after the right turn intention detection unit B114a detects the right turn intention, that is, after the right turning vehicle VA displays its right turn intention by entering the right turn lane L11 or by operating a right turn signal, on the basis of the current position Pa of the right turning vehicle VA on the road map. Then, the first notification issuance timing setting unit B116a sets the timing at which presence of the right turning vehicle VA at the predetermined position relative to the intersection CS is detected as a first notification issuance timing. The first notification issuance timing set by the first notification issuance timing setting unit B116a is the timing at which the right turning vehicle VA performs notification issuance for information presentation. The notification issuances performed at the first notification issuance timing and the second notification issuance timing described below, or notification issuances for information presentation and alarm that the controller 101a executes correspond to the "notification issuance in the first mode" directed at the right turning vehicle VA.

[0053] The second notification issuance timing setting unit B117a monitors a behavior of the right turning vehicle VA after the setting of the first notification issuance timing. The second notification issuance timing setting unit B117a regards a point at which a path TRa where the right turning vehicle VA travels when the right turning vehicle VA passes the intersection CS and a path TRb where the straight traveling vehicle VB travels when the straight traveling vehicle VB passes the intersection CS intersect as a "predicted collision point" CPP and detects that the right turning vehicle VA is traveling toward the predicted collision point CPP or has approached the predicted collision point CPP by a predetermined distance after the setting of the first notification issuance timing on the basis of the current position Pa of the right turning vehicle VA on the road map. Then, the second notification issuance timing setting unit B117a sets the timing at which any of these behaviors is detected in the right turning vehicle VA as a second notification issuance timing. The second notification issuance timing set by the second notification issuance timing setting unit B117a is a timing at which the right turning vehicle VA performs notification issuance for alarm.

[0054] Fig. 13 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at a timing when the right turning vehicle VA exceeds the stop line SL1 in the right turn lane L11 and enters the intersection CS. Fig. 13 illustrates only the right turn lane L11 and the straight lane L22 in the road R with two lanes on each side by simplifying the illustration of the road R (the same applies to Figs. 14, 15, 16, 17, 18, 20 and 21, which will be described later).

[0055] In the present embodiment, an intersection area ACS is set as a determination criterion to recognize the relative positional relationship between the right turning vehicle VA and the intersection CS. The setting of the intersection area ACS may be performed by the determination area setting unit B120a described later. The intersection area ACS is set to overlap a path TRa along which the right turning vehicle VA travels when passing the intersection CS, and the presence of the right turning vehicle VA at the predetermined relative position to the intersection area ACS is detected by arrival of the right turning vehicle VA at the intersection area ACS or entrance thereof into the intersection area ACS after displaying its right turn intention. The intersection area ACS is set as a circular area that has a predetermined radius φacs concentrically with the intersection center CTR. Figs. 13 to 18, 20 and 21illustrate the intersection area ACS by two-dotted chain lines, illustrate the traveling path TRa of the right turning vehicle VA by one-dotted chain lines, and illustrate a predicted collision area ACP and a traveling path TRb of the straight traveling vehicle VB, which will be described later, by dashed lines and one-dotted chain lines, respectively.

[0056] Fig. 14 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at a timing at which the right turning vehicle VA moves ahead inside the intersection CS and approaches the intersection center CTR after entering the intersection CS.

[0057] In the present embodiment, the predicted collision area ACP with the predicted collision point CPP included at its center is set as an area that is different from the intersection area ACS. The setting of the predicted collision area ACP may be performed by the determination area setting unit B120a similarly to the intersection area ACS. The traveling of the right turning vehicle VA toward the predicted collision point CPP in the intersection area ACS or presence of the right turning vehicle VA in the predicted collision area ACP is detected after entering the intersection area ACS. The predicted collision area ACP is set as a circular area that has a predetermined radius φacp and has a smaller area than the intersection area ACS.

[0058] The shape of the intersection area ACS is not limited to the circular shape and may be a shape (for example, a quadrangular shape having four corners at a corner cut) following a range in which the two intersecting roads overlap or may be a shape within a range surrounded by the stop lines SL1, SL2, SL3 and SL4 (Fig. 12) provided in the intersecting roads, respectively. The same applies to the predicted collision area ACP, and it is possible to set a shape other than the circular shape, such as a quadrangular shape (for example, a quadrangular shape having two sides that are parallel to a road boundary line defining the opposite straight lane L22).

[0059] The first notification issuing unit B118a outputs a command signal to issue a notification for information presentation to the HMI device 131a included in the host vehicle (that is, the right turning vehicle VA) under a condition that a first predetermined notification issuance condition defined in advance in regard to the position Pb of another vehicle, which is the straight traveling vehicle VB, is established at a first notification issuance timing that the first notification issuance timing setting unit B116a has set.

[0060] The first predetermined notification issuance condition is that the straight traveling vehicle VB is present at a first predetermined distance (hereinafter, referred to as an "information presentation distance") Dth1, which is relatively long, from the intersection CS or at a position closer to the intersection CS than the first predetermined distance Dth1. In the present embodiment, the distance from the outer edge of the predicted collision area ACP, specifically, an intersecting point between the traveling path TRb of the straight traveling vehicle VB and the circle (the circle illustrated by the dashed line in the drawings) defining the outer edge of the predicted collision area ACP to the straight traveling vehicle VB as illustrated in Figs. 13 and 14 is employed as a distance Db from the intersection CS to the straight traveling vehicle VB.

[0061] The HMI device 131a that has received the command signal from the first notification issuing unit B118a issues a notification to promote the driver of the right turning vehicle VA to recognize that the straight traveling vehicle VB traveling toward the intersection CS in the opposite straight lane L22 is present at least using sound. The notification issuance performed by the first notification issuing unit B118a is notification issuance to present information for relatively low urgency in regard to collision between the right turning vehicle VA and the straight traveling vehicle VB.

[0062] The second notification issuing unit B119a outputs a command signal to issue a notification for alarm to the HMI device 131a under a condition that a second predetermined notification issuance condition defined in advance in regard to the position Pb of the straight traveling vehicle VB is established at a second notification issuance timing that the second notification issuance timing setting unit B117a has set.

[0063] The second predetermined notification issuance condition is that the straight traveling vehicle VB is present at a second predetermined distance (hereinafter, referred to as an "alarm distance") Dth2, which is shorter than the information presentation distance Dth1, from the intersection CS or at a position closer to the intersection CS than the second predetermined distance Dth2.

[0064] The notification issuance for alarm is notification issuance at least using sound and is notification issuance using different sound from the notification issuance for information presentation. The HMI device 131a that has received the command signal from the second notification issuing unit B119a issues a notification to promote the driver of the right turning vehicle VA to recognize higher urgency in regard to collision between the right turning vehicle VA and the straight traveling vehicle VB at least using sound. The notification issuance performed by the second notification issuing unit B119a is notification issuance that is more prominent and more auditorily appealing to the driver or is notification issuance that is more prominent and more visually and auditorily appealing to the driver, as compared with the notification issuance performed by the first notification issuing unit B118a.

[0065] The first notification issuing unit B118a and the second notification issuing unit B119a can also provide a notification that the notification in each mode has been issued to the straight traveling vehicle VB via the transmitter 121a in accordance with the output of the command signal to the HMI device 131a and promote a notification to be issued in an appropriate mode in accordance with urgency in regard to collision against the host vehicle (that is, the right turning vehicle VA).

[0066] Fig. 11 is an explanatory diagram illustrating a method of calculating the information presentation distance Dth1 and the alarm distance Dth2.

[0067] The information presentation distance Dth1 and the alarm distance Dth2 are calculated as a distance by which the straight traveling vehicle VB is expected to travel before stopping after the notification issuance, that is, the distance required by the straight traveling vehicle VB to stop on the basis of the vehicle speed VSPb of the straight traveling vehicle VB and deceleration degrees DEC1 and DEC2 set in advance in accordance with the modes of the notification issuance. Hereinafter, the deceleration degree DEC1 may be referred to as a "first predetermined deceleration degree DEC1". The deceleration degree DEC2 may be referred to as a "second predetermined deceleration degree DEC2".

[0068] Specifically, the information presentation distance Dth1 is calculated by adding the distances for which the straight traveling vehicle VB is expected to travel for a break reaction time PRD1 and a deceleration time PRD2 on the basis of the vehicle speed VSPb (= V1) of the straight traveling vehicle VB at the first notification issuance timing that the first notification issuance timing setting unit B116a has set. The break reaction time PRD1 is a total time of a reaction time required for perception, judgment, and operation before the driver actually performs a brake operation after the notification issuance and an operation delay time for the system, hydraulic equipment, and the like in response to the brake operation. In the present embodiment, the break reaction time PRD1 is set in advance as a constant time (= ΔT). The deceleration time PRD2 is a time required for the vehicle to come to a stop after the brake actually starts to work and can be calculated on the basis of the vehicle speed VSPb and the deceleration degree DEC1 (PRD2 = V1 / DEC1). The deceleration degree DEC1 is, for example, - 0.1G. In this manner, the calculation of the information presentation distance Dth1 is given by Equation (1) below. Dth 1 = V 1 × ΔT + V 1 × V 1 / DEC 1 / 2

[0069] Although the alarm distance Dth2 is similarly calculated by adding the distance for which the straight traveling vehicle VB is expected to travel for each of the break reaction time PRD1 and the deceleration time PRD2, the deceleration degree DEC2 which is different from that used to calculate the information presentation distance Dth1 is employed. The deceleration degree DEC2 for calculating the alarm distance is a higher deceleration degree than the deceleration degree DEC1 for calculating the information presentation distance, in other words, a deceleration degree having a larger absolute value than that of the deceleration degree DEC1 (|DEC1| < |DEC2|). The deceleration degree DEC2 is, for example, -0.2G. Specifically, it is given by Equation (2) below. The vehicle speed V1 used in the calculation of the alarm distance Dth2 is the vehicle speed VSPb of the straight traveling vehicle VB at the second notification issuance timing. However, for simplification, the vehicle speed VSPb at the first notification issuance timing may be used instead. Dth 2 = V 1 × ΔT + V 1 × V 1 / DEC 2 / 2

[0070] Returning to Fig. 2, the determination area setting unit B120a sets the intersection area ACS and the predicted collision area ACP. The determination area setting unit B120a sets these areas ACS and ACP in association with the road map, and in the present embodiment, sets these areas ACS and ACP on the map in the range or the section extracted by the road map storage unit B113a.

[0071] Both the intersection area ACS and the predicted collision area ACP can be set to have variable sizes. In the present embodiment, both the intersection area ACS and the predicted collision area ACP are set as circular areas, and the radii thereof, that is, the distances φacs and φacp from the intersection center CTR and the predicted collision point CPP to the outer edges of the areas ACS and ACP, respectively, can be changed. The centers of the areas ACS and ACP are maintained at the intersection center CTR and the predicted collision point CPP before and after the changes in sizes or radii.

[0072] The determination area setting unit B120a sets the intersection area ACS and also sets the predicted collision area ACP at a timing before the right turning vehicle VA reaches the intersection CS after the right turning vehicle VA displays its right turn intention. Then, the size of the predicted collision area ACP is changed in accordance with an actual driving state of the right turning vehicle VA in the intersection area ACS at a timing at which or after the right turning vehicle VA reaches the intersection area ACS after the areas ACS and ACP are set.

[0073] Specifically, the determination area setting unit B120a sets the intersection area ACS to have a size in accordance with the vehicle speed VSPa of the right turning vehicle VA and also sets the predicted collision area ACP to have a predetermined size as a basis at the timing before the right turning vehicle VA reaches the intersection CS. As for the setting of the intersection area ACS, the intersection area ACS is expanded as the vehicle speed VSPa increases.

[0074] On the other hand, the size of the predicted collision area ACP is changed to a size in accordance with the vehicle speed VSPa of the right turning vehicle VA in the intersection area ACS while the size of the intersection area ACS is maintained as a prescribed size, that is, the basic size, at the timing at which or after the right turning vehicle VA reaches the intersection area ACS. Specifically, the predicted collision area ACP is reduced in size as the vehicle speed VSPa decreases. In the present embodiment, the size of the predicted collision area ACP is maintained in a case where the vehicle speed VSPa at the time of or after the arrival at the intersection area ACS is higher than a predetermined vehicle speed Vth2 corresponding to a reduced speed, and the predicted collision area ACP is reduced in size in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed Vth2 and the right turning vehicle VA is in a state of traveling at a reduced speed or is temporarily stopped. For example, the predicted collision area ACP is set to the smallest size in the setting.

[0075] Fig. 15 is a schematic diagram illustrating a setting status in a case where the intersection area ACS is expanded.

[0076] The determination area setting unit B120a sets the intersection area ACS to have a size in accordance with the vehicle speed VSPa of the right turning vehicle VA before the right turning vehicle VA reaches the intersection CS. In other words, the setting of the intersection area ACS is performed at the timing when the right turning vehicle VA is located at a position spaced apart from the intersection CS, and the setting of the size and the radius φacs of the intersection area ACS is performed based on a pre-notification issuance time Ppre in accordance with the vehicle speed VSPa of the right turning vehicle VA and the vehicle speed VSPb of the straight traveling vehicle VB.

[0077] The determination area setting unit B120a has a preset deceleration rate DEC1 and detects the vehicle speeds VSPa and VSPb of the right turning vehicle VA and the straight traveling vehicle VB, respectively, at the timing illustrated in Fig. 15 before the right turning vehicle VA reaches the intersection CS. In the present embodiment, the deceleration rate DEC1 is the same as the predetermined deceleration rate DEC1 used for calculating the previously mentioned information presentation distance Dth1.

[0078] Referring to Fig. 11, the determination area setting unit B120a calculates the pre-notification issuance time Ppre until the vehicle speed VSPb of the straight traveling vehicle VB decreases to zero at the deceleration rate DEC1 from the current vehicle speed (= V1). The calculation of the pre-notification issuance time Ppre is performed by Equation (3) below. Considering a brake reaction time ΔT after the notification issuance, Equation (4) below may be adopted. Ppre = VSPb / DEC 1 Ppre = ΔT + VSPb / DEC 1

[0079] Then, the determination area setting unit B120a multiplies the pre-notification issuance time Ppre by the vehicle speed VSPa of the right turning vehicle VA and sets the thus obtained distance as the radius φacs of the intersection area ACS. φacs = Ppre × VSPa

[0080] Note that in the present embodiment, the determination area setting unit B120a sets an intersection area (hereinafter, referred to as "expanded intersection area") ACSe is defined by enlarging the area or radius φacs based on the vehicle speeds VSPa and VSPb when the vehicle speed VSPa is higher than a predetermined vehicle speed, and sets an intersection area (hereinafter, referred to as "basic intersection area" in some times) ACSb, which has a standard predetermined area or radius φacs, is defined when the vehicle speed VSPa is equal to or lower than the predetermined vehicle speed.

[0081] Fig. 16 is a schematic diagram illustrating a setting status in a case where the predicted collision area ACP is reduced in size.

[0082] As mentioned earlier, the size of the predicted collision area ACP is reduced to the smallest size in the setting in a case where the right turning vehicle VA is in a state of traveling at a reduced speed or is temporarily stopped at a timing before the right turning vehicle VA reaches the predicted collision area ACP after the right turning vehicle VA enters the intersection area ACS in the present embodiment. The predicted collision area ACP with the smallest size has a diameter that substantially coincides with a lane width W of the lane where the straight traveling vehicle VB is traveling, that is, the straight traveling lane L22 (φacp × 2 = W).

[0083] In addition to the above, the controller 101a includes the pedestrian detection unit B121a and a third notification issuing unit B122a.

[0084] The pedestrian detection unit B121a detects a pedestrian who is present in the intersection surrounding area AAC, for example, a pedestrian crossing the crosswalk PC3 after the right turn of the right turning vehicle VA. In the present embodiment, the detection of a pedestrian is based on position information in regard to the pedestrian that can be acquired from the mobile communication device (a smartphone, for example) 201 that the pedestrian has. The pedestrian detection unit B121a identifies the position of the pedestrian on the road map from the acquired position information and determines that the position of the pedestrian is within the range of the map set as the intersection surrounding area AAC.

[0085] The third notification issuing unit B122a outputs a command signal to perform notification issuance to promote the host vehicle (that is, the right turning vehicle VA) to pay attention to the pedestrian (hereinafter, referred to as "pedestrian caution notification issuance") to the HMI device 131a included in the host vehicle in a case where the pedestrian detection unit B121a detects the pedestrian in the intersection surrounding area AAC. It is preferable that the notification issuance based on the command from the third notification issuing unit B122a, that is, the pedestrian caution notification issuance be typically performed at a timing other than the timings at which the notification issuances for information presentation and alarm are performed for the right turning vehicle VA. This can be realized by selecting a timing other than the timings at which the commands for information presentation and alarm are provided and detecting the pedestrian at the timing, and in a case where a command to perform the notification issuance for information presentation or alarm and a command to perform pedestrian caution notification issuance occur at the same time, this can also be realized by placing priority on the notification issuance based on the former command. In the present embodiment, the third notification issuing unit B122a outputs a signal to notify the controller 101b of the fact that the pedestrian caution notification issuance has been performed, in addition to the output of the command signal to the HMI device 131a. The controller 101b performs notification issuance to promote the host vehicle (that is, the straight traveling vehicle VB) to pay attention to the right turning vehicle VA on the basis of the signal. As described above, in the present embodiment, the third notification issuing unit B122a is equipped with both a function to perform pedestrian caution notification issuance and a function to perform notification issuance to promote the straight traveling vehicle VB to pay attention to the right turning vehicle VA when the right turning vehicle VA detects a pedestrian by the pedestrian detection unit B121a. Here, these notification issuances triggered by the detection of a pedestrian may be referred to as "notification issuance to call for attention", distinguishing them from the notification issuances for information presentation and alarm. The pedestrian caution notification issuance corresponds to the "notification issuance in the second mode" for the right turning vehicle VA, and the notification issuance to promote the straight traveling vehicle VB to pay attention corresponds to the "notification issuance in the third mode".

[0086] Fig. 17 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at the timing at which the pedestrian caution notification issuance is performed.

[0087] In the present embodiment, it is preferable that the pedestrian caution notification issuance be performed in a case where the straight traveling vehicle VB is located at a position farther from the intersection CS than the information presentation distance Dth1 at a timing after the right turning vehicle VA enters the intersection area ACS. At the timing illustrated in Fig. 17, the controller 101a does not perform the notification issuance for information presentation since the straight traveling vehicle VB is not present at the information presentation distance Dth1 from the intersection CS and at the position closer to the intersection CS than the information presentation distance Dth1.

[0088] In other words, it is preferable that the pedestrian caution notification issuance be performed under a condition that the pedestrian has been detected in the intersection surrounding area AAC in a case where the notification issuance for information presentation is not performed by the straight traveling vehicle VB being located at a position farther from the intersection CS than the information presentation distance Dth1 after the right turning vehicle VA enters the intersection area ACS in the present embodiment. Then, the pedestrian caution notification issuance is stopped, and the notification issuance for information presentation in regard to collision between the right turning vehicle VA and the straight traveling vehicle VB is performed, at a timing at which the straight traveling vehicle VB has traveled forward and approached the information presentation distance Dth1 from the intersection CS. Furthermore, in a case where the right turning vehicle VA has entered the predicted collision area ACP and the straight traveling vehicle VB has also approached the alarm distance Dth2 from the intersection CS or a position closer to the intersection CS than the alarm distance Dth2, the mode for the notification issuance is switched from the information presentation to the alarm.

[0089] The HMI device 131a, which has received the command signal from the third notification issuing unit B122a, produces at least sound as the pedestrian caution notification issuance. In the present embodiment, the pedestrian caution notification issuance is performed in response to transmission of a command from the third notification issuing unit B122a to the HMI device 131a. Also, when the pedestrian caution notification issuance is performed, different sound is adopted between a case where the right turning vehicle VA is located in the predicted collision area ACP and a case where the right turning vehicle VA is not located in the predicted collision area ACP. When the pedestrian caution notification issuance is performed, different display may be further adopted between a case where the right turning vehicle VA is located in the predicted collision area ACP and a case where the right turning vehicle VA is not located in the predicted collision area ACP. Specifically, notification issuance for the purpose of promoting the driver of the right turning vehicle VA to recognize the presence of the pedestrian in the intersection surrounding area AAC in a case where the right turning vehicle VA is located outside the predicted collision area ACP and a relatively long time has been secured for the right turning vehicle VA to reach the crosswalk PC3 after the right turn, while notification issuance for the purpose of promoting the driver to perform an operation to avoid contact with the pedestrian in a case where the right turning vehicle VA is located in the predicted collision area ACP and has approached a location right before the crosswalk PC3 after the right turn.

[0090] The sound and the display used when the pedestrian caution notification issuance is performed, in other words, the mode for the pedestrian caution notification issuance may be different not only between the case where the right turning vehicle VA is located in the predicted collision area ACP and the case where the right turning vehicle VA is not located in the predicted collision area ACP but also between a case where the right turning vehicle VA is traveling at the vehicle speed VSPa that is higher than a predetermined vehicle speed toward the predicted collision point CPP outside the predicted collision area ACP or is located in the predicted collision area ACP and the other case, that is, a case where the right turning vehicle VA is located outside the predicted collision area ACP and the vehicle speed VSPa is lower than the predetermined vehicle speed.

[0091] In the present embodiment, the controller 101a included in the right turning vehicle VA and the controller 101b included in the straight traveling vehicle VB have basically similar configurations and include mutually corresponding elements.

[0092] As illustrated in Fig. 3, the controller 101b includes a host vehicle position detection unit B111b, an other vehicle position detection unit B112b, a road map storage unit B113b, a right turn intention detection unit B114b, a driving state detection unit B115b, a first notification issuance timing setting unit B116b, a second notification issuance timing setting unit B117b, a first notification issuing unit B118b, a second notification issuing unit B119b and a determination area setting unit B120b. Although the controller 101b may include components corresponding to the pedestrian detection unit B121a and the third notification issuing unit B122a, these components are not illustrated because, in the present embodiment, they are not required elements for the straight traveling vehicle VB. Differences between an internal configuration of the controller 101b and that of the controller 101a will be mainly described below.

[0093] The host vehicle position detection unit B111b is adapted to detect the current position Pb of the straight traveling vehicle VB, which is the host vehicle, and the detection of the current position Pb is based on an output signal from the position sensor 111b included in the straight traveling vehicle VB.

[0094] The other vehicle position detection unit B112b is adapted to detect the current position Pa of the right turning vehicle VA, which is another vehicle, and the detection of the current position Pa is based on reading of position information indicating the current position Pa from vehicle information acquired from the right turning vehicle VA via the receiver 122b included in the straight traveling vehicle VB.

[0095] Similarly to the road map storage unit B113a, the road map storage unit B113b stores a road map that includes the intersection CS and includes the assigned link ID of each lane leading to the intersection CS and specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA, respectively, on the road map. Although the road maps stored in the road map storage units B113b and B113a may have different levels of accuracy, both the maps employ an accuracy that is compatible with satellite positioning using GNSS in the present embodiment.

[0096] The right turn intention detection unit B114b is adapted to detect a right turn intention of the right turning vehicle VA, and the detection of the right turn intention is based on identification of the link ID of the lane where the right turning vehicle VA is present from the current position Pa of the right turning vehicle VA or reading of information indicating an operating status of the right turn signal from vehicle information acquired from the right turning vehicle VA via the receiver 122b. It is also possible to include the link IDs of the lanes where the vehicles VA and VB are present in vehicle information exchanged between the straight traveling vehicle VB and the right turning vehicle VA and to detect the right turn intention of the right turning vehicle VA on the basis of the link IDs acquired through communication.

[0097] The driving state detection unit B115b is adapted to detect the vehicle speed VSPa of the right turning vehicle VA as the driving state of the right turning vehicle VA, and the detection of the vehicle speed VSPa is based on reading of vehicle speed information indicating the vehicle speed VSPa from vehicle information acquired from the right turning vehicle VA via the receiver 122b.

[0098] The first notification issuance timing setting unit B116b detects that the right turning vehicle VA is located at a predetermined relative position to the intersection CS after showing its right turn intention based on the current position Pa of the right turning vehicle VA on the road map. Specifically, the first notification issuance timing setting unit B116b compares the current position Pa of the right turning vehicle VA with the intersection area ACS and detects that the right turning vehicle VA has arrived at the intersection area ACS or has entered the intersection area ACS similarly to the above description. And then, the first notification issuance timing setting unit B116b sets the detected timing as the first notification issuance timing. The first notification issuance timing set by the first notification issuance timing setting unit B116b is the timing at which the notification issuance for information presentation is executed in the straight traveling vehicle VB. The notification issuances performed at the first notification issuance timing and the second notification issuance timing described below, or notification issuances for information presentation and alarm that the controller 101b executes correspond to the "notification issuance in the first mode" directed at the straight traveling vehicle VB.

[0099] The size and the shape of the intersection area ACS may be the same or different between the controller 101a and the controller 101b. It is possible to set the shape of the intersection area ACS to be variable between those controllers 101a and 101b in accordance with a drivers' selection or trends of driving states at the time of passing the intersection CS, for example.

[0100] The second notification issuance timing setting unit B117b monitors the behavior of the right turning vehicle VA after entering the intersection CS based on the current position Pa of the right turning vehicle VA on the road map and detects that the right turning vehicle VA is traveling toward the predicted collision point CPP in the intersection area ACS or present in the predicted collision area ACP after entering the intersection area ACS. And then, the second notification issuance timing setting unit B117b sets the timing at which anyone of those behaviors is detected in the right turning vehicle VA as the second notification issuance timing. The second notification issuance timing set by the second notification issuance timing setting unit B117b is the timing at which the notification issuance for alarm is executed in the straight traveling vehicle VB.

[0101] Although the size and the shape of the predicted collision area ACP may be different between the controller 101a and the controller 101b, similar setting is adopted for both in the present embodiment. The predicted collision area ACP may be set to have the same size and shape in both controller 101a and controller 101b, or coordinate information of the predicted collision area ACP set in one of the controllers 101a and 101b may be provided to and set in the other controller through vehicle-to-vehicle communication.

[0102] The first notification issuing unit B118b outputs a command signal to issue the notification for information presentation to the HMI device 131b included in the host vehicle (that is, the straight traveling vehicle VB) under a condition that the first predetermined notification issuance condition related to the position Pb of the straight traveling vehicle VB is established at the first notification issuance timing set by the first notification issuance timing setting unit B116b. Similarly to the above description, the first predetermined notification issuance condition is that the straight traveling vehicle VB is located at the information presentation distance Dth1 from the intersection CS or is present at a position closer to the intersection CS than the information presentation distance Dth1.

[0103] The HMI device 131b that has received the command signal from the first notification issuing unit B118b issues a notification to promote the driver of the straight traveling vehicle VB to recognize that the right turning vehicle VA which the driver should pay attention to is present in the right turn lane L11 in the opposite lanes at least using sound. Similarly to the above description, the notification issuance performed by the first notification issuing unit B118b is notification issuance to present information for relatively low urgency in regard to collision between the straight traveling vehicle VB and the right turning vehicle VA.

[0104] The second notification issuing unit B119b outputs a command signal to issue the notification for alarm to the HMI device 131b under a condition that the second predetermined notification issuance condition related to the position Pb of the straight traveling vehicle VB is established at the second notification issuance timing set by the second notification issuance timing setting unit B117b. The second predetermined notification issuance condition is that the straight traveling vehicle VB is located at the alarm distance Dth2 from the intersection CS or is present at a position closer to the intersection CS than the alarm distance Dth2.

[0105] The HMI device 131b that has received the command signal from the second notification issuing unit B119b issues a notification to promote the driver of the straight traveling vehicle VB to recognize higher urgency in regard to collision between the straight traveling vehicle VB and the right turning vehicle VA at least using sound. Similarly to the above description, the notification issuance performed by the second notification issuing unit B119b is also notification issuance that is more prominent and more auditorily appealing to the driver or is more prominent and more visually and auditorily appealing to the driver.

[0106] The first notification issuing unit B118b and the second notification issuing unit B119b can also notify the right turning vehicle VA of the fact that the notification in each mode has been issued via the transmitter 121b in accordance with the output of the command signal to the HMI device 131b.

[0107] The determination area setting unit B120b sets the intersection area ACS and the predicted collision area ACP. Similarly to the above description, the determination area setting unit B120b sets these areas ACS and ACP on the map in the range or the section extracted by the road map storage unit B113b.

[0108] The intersection area ACS and the predicted collision area ACP can also be set to have variable sizes by the controller 101b, and both the intersection area ACS and the predicted collision area ACP are set as circular areas, allowing the radii thereof, that is, the distances φacs and φacp from the intersection center CTR and the predicted collision point CPP to the outer edges of the areas ACS and ACP to be changed.

[0109] The determination area setting unit B120b sets the intersection area ACS and the predicted collision area ACP at a timing before the right turning vehicle VA reaches the intersection CS after the right turn intention of the right turning vehicle VA is detected.

[0110] In the present embodiment, the setting of the intersection area ACS and the predicted collision area ACP by the determination area setting unit B120b follows a procedure similar to that for the setting of the areas ACS and ACP by the determination area setting unit B120a.

[0111] Specifically, the determination area setting unit B120b sets the intersection area ACS to have a size corresponding to the vehicle speed VSPa of the right turning vehicle VA and sets the predicted collision area ACP to have a predetermined base size at the timing before the right turning vehicle VA reaches the intersection CS. The configuration of the intersection area ACS is based on expanding the intersection area ACS as the vehicle speed VSPa increases. The determination area setting unit B120b modifies the size of the predicted collision area ACP to a size in accordance with the vehicle speed VSPa of the right turning vehicle VA in the intersection area ACS at a timing after the right turning vehicle VA reaches the intersection area ACS or after the right turning vehicle VA reaches the intersection area ACS, and contracts the predicted collision area ACP to have a reduced size as the vehicle speed VSPa decreases. In the present embodiment, in a case where the vehicle speed VSPa at the time of or after reaching the intersection area ACS is equal to or less than the predetermined vehicle speed Vth2, and the right turning vehicle VA is in a slowed-down state or in a temporarily stopped state inside the intersection area ACS, the predicted collision area ACP is reduced in size to the smallest size in terms of setting, specifically, to have a diameter that substantially corresponds to the lane width W of the straight traveling lane L22.

[0112] It is desirable that the notifications for the drivers do not hinder driving of the drivers and be easy for the drivers to know targets to which attention is to be paid. In other words, it is desirable that the notification issuance performed when the right turning vehicle VA turns right at the intersection CS enable the driver of the right turning vehicle VA to easily recognize whether the target to which attention is to be paid is the straight traveling vehicle VB or the object to be monitored.

[0113] Therefore, the notification issuance in the first mode and the notification issuance in the second mode are performed with mutually different sounds via the HMI device 131a as the output unit in the right turning vehicle VA.

[0114] Specifically, a voice such as "There is a straight traveling vehicle", "A straight traveling vehicle is there", or "A straight traveling vehicle is right there", for example, is emitted from the speaker 141a of the HMI device 131a in accordance with a situation in the notification issuance in the first mode in the right turning vehicle VA. Also, a voice such as "There is a pedestrian", "A pedestrian is there", or "A pedestrian is right there", for example, is emitted from the speaker 141a of the HMI device 131a in accordance with a situation in the notification issuance in the second mode in the right turning vehicle VA. Such a notification issuance with a voice based on a relatively short sentence enables the driver to understand the content of the notification in a short period of time without his / her driving being hindered. Therefore, the driver of the right turning vehicle VA can easily identify the notification issuance in the first mode and the notification issuance in the second mode by a difference in voices, that is, a difference in content of the notifications by the voices. Therefore, the driver can accurately recognize, on the basis of the different voices, that is, the different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode without his / her driving being hindered even in a situation where the driver is focusing on the front side for driving.

[0115] Fig. 22 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the right turning vehicle.

[0116] Fig. 23 is a schematic diagram illustrating an example of the notification issuance in the second mode through display in the notification control performed in the right turning vehicle.

[0117] Furthermore, as illustrated in Figs. 22 and 23, the notification issuance in the first mode and the notification issuance in the second mode are preferably performed through different displays via the HMI device 131a in the right turning vehicle VA. This enables the driver of the right turning vehicle VA to more accurately recognize, on the basis of different displays in addition to different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode.

[0118] Specifically, as illustrated in Fig. 22, information VBT indicating the type of the straight traveling vehicle VB, which is the counterpart vehicle of the right turning vehicle VA, and information VBTD indicating the traveling direction (straight traveling direction) of the straight traveling vehicle VB are displayed in a display region DAa that a display 143a of the HMI device 131a has in the right turning vehicle VA on the basis of the straight traveling vehicle information related to the straight traveling vehicle VB obtained via communication between the right turning vehicle VA and the straight traveling vehicle VB in the notification issuance in the first mode. In the example in Fig. 22, the information VBT indicating a four-wheeled vehicle as the type of the straight traveling vehicle VB is displayed by illustration, and the information VBTD indicating the straight traveling direction as the traveling direction of the straight traveling vehicle VB is displayed by illustration and text. The information VBTD includes information VBTD1 displayed by illustration and information VBTD2 displayed by text. Note that the content of the notification issuance in the first mode through display and the content of the notification issuance in the frist mode through sound do not need to be completely identical. This premise in the notification issuance in the first mode is also applicable to the notification issuance in the second mode and the notification issuance in the third mode.

[0119] As illustrated in Fig. 23, information PE indicating presence of the object to be monitored detected by the pedestrian detection unit B121a is displayed in the display region DAa that the display 143a of the HMI device 131a has in the right turning vehicle VA in the notification issuance in the second mode. In the example in Fig. 23, the information PE is displayed by illustration and text. The information PE includes information PE1 displayed by illustration and information PE2 displayed by text.

[0120] Fig. 24 is a schematic diagram illustrating an example of the notification issuance in the first mode through display in the notification control performed in the straight traveling vehicle.

[0121] Note that as illustrated in Fig. 24, information VAT indicating the type of the right turning vehicle VA, which is the counterpart vehicle of the straight traveling vehicle VB, and information VATD indicating the traveling direction (right turning direction) of the right turning vehicle VA are preferably displayed in a display region DAb that a display 143b of the HMI device 131b has in the straight traveling vehicle VB on the basis of right turning vehicle information related to the right turning vehicle VA obtained via communication between the right turning vehicle VA and the straight traveling vehicle VB in the notification issuance in the first mode. In the example of Fig. 24, the information VAT is displayed by illustration, and the information VATD is displayed by illustration and text. The information VATD includes information VATD1 displayed by illustration and information VATD2 displayed by text. In the notification issuance in the first mode through display in the right turning vehicle VA, it is preferable that the information VBT indicating the type of the straight traveling vehicle VB and the information VBTD indicating the traveling direction of the straight traveling vehicle VB be displayed in a first color in the display region DAa on the display 143a in the notification issuance for information presentation, and the information VBT and the information VBTD be displayed in a second color, which is different from the first color, in the display region DAa on the display 143a in the notification issuance for alarm. Similarly, in the notification issuance in the first mode through display in the straight traveling vehicle VB, it is preferable that the information VAT and the information VATD be displayed in the first color in the display region DAb on the display 143b in the notification issuance for information presentation, and the information VAT and the information VATD be displayed in the second color in the display region DAb on the display 143b in the notification issuance for alarm. The first color is, for example, yellow, and the second color is, for example, red.

[0122] Furthermore, it is preferable that the notification issuance in the first mode be performed with different sounds in a case where the right turning vehicle VA is present in the expanded intersection area ACSe and in a case where the right turning vehicle VA is present in the intersection area ACS other than the expanded intersection area ACSe, that is, in the basic intersection area ACSb.

[0123] Specifically, the driver of the right turning vehicle VA can recognize the straight traveling vehicle VB that is a target to which attention is to be paid in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to allow the distance before arrival at the intersection CS to become relatively long, which leads to extra time, by the driver of the right turning vehicle VA identifying the notification issuance in the first mode by the sound in the case where the right turning vehicle VA is present in the expanded intersection area ACSe. Therefore, the driver of the right turning vehicle VA can execute a safer action to avoid collision against the straight traveling vehicle VB at the timing at which the right turning vehicle VA reaches the intersection CS. Similarly, the driver of the straight traveling vehicle VB can recognize the right turning vehicle VA that is a target to which attention is to be paid in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to allow the distance before arrival at the intersection CS to become relatively long, which leads to extra time, by the driver of the straight traveling vehicle VB identifying the notification issuance in the first mode by the sound in the case where the right turning vehicle CA is present in the expanded intersection area ACSe. Therefore, the driver of the straight traveling vehicle VB can execute a safer action to avoid collision against the right turning vehicle VA just in a case where the right turning vehicle VA tries to turn right at the intersection CS before the straight traveling vehicle VB passes the intersection CS.

[0124] Note that in the notification issuance in the first mode, a voice "There is a straight traveling vehicle", for example, in a case where the right turning vehicle VA is present in the expanded intersection area ACSe or a voice "A straight traveling vehicle is there", for example, in a case where the right turning vehicle VA is present in the basic intersection area ACSb is emitted from the speaker 141a of the HMI device 131a in the right turning vehicle VA. Also, in the notification issuance in the first mode, a voice "There is a right turning vehicle", for example, in a case where the right turning vehicle VA is present in the expanded intersection area ACSe or a voice "A right turning vehicle is there", for example, in a case where the right turning vehicle VA is present in the basic intersection area ACSb is emitted from the speaker 141b of the HMI device 131b in the straight traveling vehicle VB.

[0125] Furthermore, the notification issuance in the second mode is preferably performed with different sounds in the case where the right turning vehicle VA is present in the expanded intersection area ACSe and in the case where the right turning vehicle VA is present in the intersection area ACS other than the expanded intersection area ACSe, that is, in the basic intersection area ACSb. In this manner, the driver of the right turning vehicle VA can recognize object to be monitored that is a target to which attention is to be paid, in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Therefore, the driver can execute a safer action to avoid collision against the object to be monitored that is a target to which attention is to be paid, at the timing at which the right turning vehicle VA reaches the intersection CS.

[0126] Note that in the notification issuance in the second mode, a voice "there is a pedestrian", for example, in a case where the right turning vehicle VA is present in the expanded intersection area ACSe or a voice "A pedestrian is right there", for example, in a case where the right turning vehicle VA is present in the basic intersection area ACSb is emitted from the speaker 141a of the HMI device 131a.

[0127] Also, the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB are preferably performed with the same sound.

[0128] Specifically, the driver of the straight traveling vehicle VB typically does not have to pay attention to the object to be monitored when passing the intersection CS. Therefore, the driver of the straight traveling vehicle VB can pay attention only to the right turning vehicle VA by performing the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB with the same sound. In other words, it is possible to provide a notification that does not hinder driving of the driver of the straight traveling vehicle VB by performing the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB with the same sound in a case where the target to which attention is to be paid does not change and is still the right turning vehicle VA.

[0129] Note that in the notification issuance in the first mode and the notification issuance in the third mode in the straight traveling vehicle VB, a voice "There is a right turning vehicle", "A right turning vehicle is right there", or "A right turning vehicle is right there", for example, is emitted from the speaker 141b of the HMI device 131b in accordance with a situation.

[0130] Moreover, it is preferable that the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB be further performed through the same display. In other words, it is preferable that the notification issuance in the third mode be also fourther performed through display illustrated in Fig. 24. By doing so, the driver of the straight traveling vehicle VB can pay attention only to the right turning vehicle VA to which it is necessary to pay attention even in a case where an object to be monitored to which it is not necessary to pay attention is detected at the intersection CS or in the intersection surrounding area AAC, which is a predetermined area around the intersection CS. In other words, it is possible to reliably provide a notification that does not hinder driving of the driver of the straight traveling vehicle VB by performing the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB through the same display in addition to the same sound in a case where the target to which attention is to be paid does not change and is still the right turning vehicle VA.

[0131] Additionally, the first notification issuing unit B118a and the third notification issuing unit B122a may perform notification issuance in a fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects the object to be monitored when the notification issuance in the first mode is being performed as notification issuance for information presentation. Furthermore, the second notification issuing unit B119a and the third notification issuing unit B122a may perform the notification issuance in the fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode as notification issuance for alarm, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects an object to be monitored when the notification issuance in the first mode as notification issuance for alarm is being performed.

[0132] Specifically, if a command signal from the third notification issuing unit B122a is further received in a situation where a command signal from the first notification issuing unit B118a has been received and the notification issuance for information presentation is being performed, then the HMI device 131a emits a voice "There are a straight traveling vehicle and a pedestrian" or "A straight traveling vehicle and a pedestrian are right there", for example, from the speaker 141a as the notification issuance in the fourth mode. Additionally, if a command signal from the third notification issuing unit B122a is further received in a situation where a command signal from the second notification issuing unit B119a has been received and the notification issuance for alarm is being performed, then the HMI device 131a emits a voice "A straight traveling vehicle and a pedestrian are right there", for example, from the speaker 141a as the notification issuance in the fourth mode. In other words, the notification issuance in the fourth mode with a sound is configured of content of notification as a combination of content of notification with a sound in the notification issuance in the first mode and content of notification with a sound in the notification issuance in the second mode. By doing so, it is possible to make the driver of the right turning vehicle VA aware of presence of a pedestrian by notification issuance in the fourth mode based on a sound and to promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm.

[0133] Fig. 25 is a schematic diagram illustrating an example of the notification issuance in the fourth mode through display in notification control performed in the right turning vehicle.

[0134] Additionally, the notification issuance in the fourth mode may be further performed through display.

[0135] Specifically, if the HMI device 131a further receives a command signal from the third notification issuing unit B122a in a situation where a command signal from the first notification issuing unit B118a has been received and notification issuance for information presentation is being performed or in a situation where a command signal from the second notification issuing unit B119a has been received and notification issuance for alarm is being performed through display on a screen as illustrated in Fig. 22 in the display region DAa on the display 143a, then the HMI device 131a displays a screen as illustrated in Fig. 25 in the display region DAa on the display 143a as the notification issuance in the fourth mode. In the example in Fig. 25, the information VBT indicating the type of the straight traveling vehicle VB and the information PE1 indicating the presence of the object to be monitored are displayed by illustration in the upper section in the display region DAa. Furthermore, the information VBTD1 indicating the traveling direction of the straight traveling vehicle VB is displayed by illustration in the middle section in the display region DAa. Information Combo indicating the presence of the straight traveling vehicle VB and the pedestrian as the target to be monitored is displayed by text in the lower section in the display region DAa. As illustrated in Figs. 22, 23, and 25, the notification issuance in the fourth mode through display is configured of content of notification as a combination of content of notification in the notification issuance in the first mode through display and content of notification in the notification issuance in the second mode through display. By doing so, it is possible to make the driver of the right turning vehicle VA aware of the presence of the pedestrian by the notification issuance in the fourth mode based on the display in addition to the sound and to reliably promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm. Note that similarly to the notification issuance in the first mode, the content of the notification issuance in the fourth mode through display and the content of the notification issuance in the fourth mode through sound also do not need to be completely identical.

[0136] In the notification system 1, it is preferable that notification issuance at least with a sound be performed until a predetermined word, a predetermined phrase, or a predetermined sentence representing content of notification is read at least once or more in a case where completion of passing of the right turning vehicle VA through the intersection CS is detected on the basis of results of specification by the road map storage units B113a and B113b when the notification issuance at least with a voice is being performed. This enables the driver to more accurately understand the content of the notification because the read content of notification does not end in the middle.

[0137] Note that examples of the predetermined sentence include "There is a straight traveling vehicle", "There is a right turning vehicle", and "There is a pedestrian" as described above. The predetermined phrase means a further shortened expression from each of these predetermined sentences, and the predetermined word means a single characteristic word from the predetermined sentence or the predetermined phrase. Additionally, the notification through display may be ended at the same time with the end of the notification issuance with a sound in a case where the notification issuance through display is performed together.(Content of Notification Control in Right Turning Vehicle)

[0138] Figs. 4 to 10 are flowcharts illustrating content of notification control performed by the controller 101a included in the right turning vehicle VA. The flowchart in Fig. 4 illustrates an overall flow of the notification control, the flowcharts in Figs. 5 to 7 illustrate content of early notification issuance processing, and the flowcharts in Figs. 8 to 10 illustrate content of normal notification issuance processing. The flowcharts in Figs. 6 and 9 illustrate content of processing (information presentation processing) executed by the right turning vehicle VA in regard to information presentation, and the flowcharts in Figs. 7 and 10 illustrate content of processing (alarm processing) executed by the right turning vehicle VA in regard to an alarm. The information presentation processing and the alarm processing are performed as parts of the notification control. The controller 101a performs the notification control every predetermined time in a case where an intersection is detected in a road in front of the host vehicle (that is, the right turning vehicle VA).

[0139] In the flowchart illustrated in Fig. 4, the controller 101a reads various kinds of control information used for the notification control in S111. The control information read in S111 includes the current position Pa, the vehicle speed VSPa and the link ID of the right turning vehicle VA which is the host vehicle, and the current position Pb, the vehicle speed VSPb and the link ID of the straight traveling vehicle VB which is another vehicle. The control information may include information regarding operating statuses of the right turn signals in the right turning vehicle VA and the straight traveling vehicle VB.

[0140] In S112, the controller 101a determines whether or not the straight traveling vehicle VB traveling in the straight direction toward the intersection CS in the lane L22 opposite to the lane L11 in which the right turning vehicle VA is present has been detected. The detection of the straight traveling vehicle VB is based on the link ID of the straight traveling vehicle VB. The processing proceeds to S113 in a case where the straight traveling vehicle VB is detected, or this control is ended in a case where the straight traveling vehicle VB is not detected.

[0141] In S113, the controller 101a determines whether or not a right turn intention of the right turning vehicle VA has been detected. The detection of the right turn intention is based on an operating status of the right turn signal of the right turning vehicle VA. Additionally or alternatively, it is also possible to make the determination on the basis of the link ID of the right turning vehicle VA. The processing proceeds to S114 in a case where the right turn intention is detected, or this control is ended in a case where the right turn intention is not detected.

[0142] In S114, the controller 101a reads the vehicle speed VSPa of the right turning vehicle VA. At the timing at which the right turn intention is detected, the right turning vehicle VA is located at a position separated from the intersection CS, that is, a position before reaching the intersection CS, and the vehicle speed VSPa at the timing at which the right turn intention is detected is the vehicle speed VSPa before the right turning vehicle VA reaches the intersection CS.

[0143] In S115, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB, specifically the vehicle speed VSPb at the timing at which the right turn intention of the right turning vehicle VA is detected.

[0144] In S116, the controller 101a sets the intersection area ACS and the predicted collision area ACP as determination areas. The setting of the intersection area ACS is based on the vehicle speed VSPa of the right turning vehicle VA and the vehicle speed VSPb of the straight traveling vehicle VB at the timing at which the right turn intention is detected. In the present embodiment, when the vehicle speed VSPa is higher than a predetermined vehicle speed, the expanded intersection area ACSe is set according to the vehicle speeds VSPa and VSPb, and when the vehicle speed VSPa is equal to or lower than the predetermined vehicle speed, the basic intersection area ACSb is set. In this embodiment, the predicted collision area ACP is set to have the same area or radius φacp regardless of whether the vehicle speed VSPa is above or below the predetermined vehicle speed. However, it is also possible to vary the size of the predicted collision area depending on the vehicle speed, such that in a case where the vehicle speed VSPa is higher than the predetermined vehicle speed, the predicted collision area ACP is expanded in conjunction with the setting of the expanded intersection area ACSe.

[0145] In 117, the controller 101a determines whether or not the expanded intersection area ACSe has been set. The processing proceeds to S118 in a case where the expanded intersection area ACSe has been set, or the processing proceeds to S119 in a case where the basic intersection area ACSb has been set, or the expanded intersection area ACSe has not been set.

[0146] In S118, the controller 101a performs early notification issuance processing using the expanded intersection area ACSe and the predicted collision area ACP.

[0147] In S119, the controller 101a performs normal notification issuance processing using the basic intersection area ACSb and the predicted collision area ACP.

[0148] In the flowchart illustrated in Fig. 5, the controller 101a reads various kinds of control information used for early notification issuance processing in S211. The control information read in S211 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0149] In S212, the controller 101a specifies the current position Pa of the right turning vehicle VA on the road map.

[0150] In S213, the controller 101a determines whether or not the right turning vehicle VA has entered the expanded intersection area ACSe. In a case where the right turning vehicle VA is located at a position of the outer edge of the expanded intersection area ACSe or is located at a position closer to the intersection center CTR than the outer edge, the right turning vehicle VA is determined to have entered the expanded intersection area ACSe, and the processing proceeds to S214. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the intersection center CTR than the outer edge of the expanded intersection area ACSe, the right turning vehicle VA is determined not to have entered the expanded intersection area ACSe, and this control is ended.

[0151] In S214, the controller 101a performs the information presentation processing for early notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 6.

[0152] In S215, the controller 101a performs the alarm processing for early notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 7.

[0153] In S216, the controller 101a determines whether or not notification issuance has been performed in the information presentation processing or the alarm processing for early notification issuance. The processing proceeds to S219 in a case where the notification issuance has been performed, or the processing proceeds to S217 in a case where the notification issuance has not been performed.

[0154] In S217, the controller 101a determines whether or not a pedestrian has been detected in the intersection surrounding area AAC. The processing proceeds to S218 in a case where a pedestrian has been detected, or the processing proceeds to S219 in a case where no pedestrians have been detected.

[0155] In S218, the controller 101a performs pedestrian caution notification issuance.

[0156] In S219, the controller 101a determines whether or not the right turning vehicle VA has passed the intersection CS. The determination of whether or not the right turning vehicle VA has passed the intersection CS is made on the basis of the fact that the right turning vehicle VA has left the expanded intersection area ACSe in the traveling direction after the right turn. The right turning vehicle VA is determined to have passed the intersection CS and this control is ended in a case where the right turning vehicle VA has left the expanded intersection area ACSe, or the right turning vehicle VA is determined not to have passed the intersection CS, the processing returns to S214, and the information presentation processing and the alarm processing are repeatedly executed until the right turning vehicle VA leaves the expanded intersection area ACSe in a case where the right turning vehicle VA is still located in the expanded intersection area ACSe.

[0157] In the flowchart illustrated in Fig. 6, the controller 101a reads various kinds of control information used for the information presentation processing in S311. The control information read in S311 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0158] In S312, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0159] In S313, the controller 101a determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP. In a case where the right turning vehicle VA is located at a position between the outer edge of the intersection area ACS and the outer edge of the predicted collision area ACP, the right turning vehicle VA is determined to be located outside the predicted collision area ACP, and the processing proceeds to S314. On the other hand, in a case where the right turning vehicle VA is located at the outer edge of the predicted collision area ACP or a position closer to the predicted collision point CPP than the outer edge, the right turning vehicle VA is determined not to be located outside the predicted collision area ACP, and the information presentation processing is ended.

[0160] In S314, the controller 101a calculates the distance from intersection CS to the straight traveling vehicle VB, in other words, a distance Db remaining in front of the straight traveling vehicle VB until arriving at the intersection CS (hereinafter, referred to as an "intersection arrival distance"). As illustrated in Fig. 13, the intersection arrival distance Db is calculated as the distance from the outer edge of the predicted collision area ACP to the straight traveling vehicle VB.

[0161] In S315, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0162] In S316, the controller 101a calculates the information presentation distance Dth1. The calculation of the information presentation distance Dth1 is based on the vehicle speed VSPb of the straight traveling vehicle VB and the first predetermined deceleration degree DEC1, as defined by the above equation (1).

[0163] In S317, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the information presentation distance Dth1, in other words, whether the straight traveling vehicle VB is located at the information presentation distance Dth1 from the intersection CS or is located at a position closer to the intersection CS than the information presentation distance Dth1. The processing proceeds to S318 in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1, or the information presentation processing is ended in a case where the intersection arrival distance Db is greater than the information presentation distance Dth1.

[0164] In S318, the controller 101a performs the notification issuance for information presentation.

[0165] In the flowchart illustrated in Fig. 7, the controller 101a reads various kinds of control information used for the alarm processing for early notification issuance in S411. The control information read in S411 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0166] In S412, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0167] In S413, the controller 101a determines whether or not the right turning vehicle VA is located inside the predicted collision area ACP is determined. In a case where the right turning vehicle VA is located at the position of the outer edge of the predicted collision area ACP or is located at the position closer to the predicted collision point CPP than the outer edge, the right turning vehicle VA is determined to be located inside the predicted collision area ACP, and the processing proceeds to S414. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the predicted collision point CPP than the outer edge of the predicted collision area ACP, the right turning vehicle VA is determined not to be located inside the predicted collision area ACP, and the alarm processing is ended.

[0168] In S414, the controller 101a calculates the intersection arrival distance Db of the straight traveling vehicle VB.

[0169] In S415, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0170] In S416, the controller 101a calculates the alarm distance Dth2. The calculation of the alarm distance Dth2 is based on the vehicle speed VSPb of the straight traveling vehicle VB and the second predetermined deceleration degree DEC2, as defined by the above equation (2).

[0171] In S417, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the alarm distance Dth2, in other words, whether the straight traveling vehicle VB is located at the alarm distance Dth2 from the intersection CS or is located at a position closer to the intersection CS than the alarm distance Dth2. The processing proceeds to S418 in the case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2, or the alarm processing is ended in a case where the intersection arrival distance Db is greater than the alarm distance Dth2.

[0172] In S418, the controller 101a performs the notification issuance for alarm.

[0173] The procedure illustrated in the flowchart in Fig. 8 differs from the procedure illustrated in the flowchart in Fig. 5 only in the processing that the controller 101a performs in S513. In S513, the controller 101a determines whether or not the right turning vehicle VA has entered the basic intersection area ACSb. In a case where the right turning vehicle VA is located at the position of the outer edge of the basic intersection area ACSb or is located at a position closer to the intersection center CTR than the position, the right turning vehicle VA is determined to have entered the basic intersection area ACSb, and the processing proceeds to S514. In S514, the controller 101a performs the information presentation processing for normal notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 9, and in subsequent S515, the controller 101a performs the alarm processing for normal notification issuance in accordance with the procedure illustrated in the flowchart in Fig. 10. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the intersection center CTR than the outer edge of the basic intersection area ACSb, the right turning vehicle VA is determined not to have entered the basic intersection area ACSb, and this control is ended. The processing that the controller 101a performs in other S511, S512, and S514 to S519 is similar to the processing that the controller 101a performs in S211, S212, and S214 to S219 illustrated in the flowchart in Fig. 5. In S516, the controller 101a determines whether or not the notification issuance has been performed in the information presentation processing or the alarm processing for normal notification issuance. In a case where the notification issuance has been performed, the processing proceeds to S519. On the other hand, in a case where the notification issuance has not been performed, the processing proceeds to S517, and the controller 101a determines whether or not a pedestrian has been detected in the intersection surrounding area AAC. Then, in a case where a pedestrian has been detected, the processing proceeds to S518, and the controller 101a performs the pedestrian caution notification issuance.

[0174] In the flowchart illustrated in Fig. 9, the controller 101a reads various kinds of control information used for the information presentation processing in S611. The control information read in S611 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0175] In S612, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0176] In S613, the controller 101a determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP. The processing proceeds to S614 in a case where the right turning vehicle VA is located outside the predicted collision area ACP, or the information presentation processing is ended in a case where the right turning vehicle VA is not located outside the predicted collision area ACP.

[0177] In S614, the controller 101a reads the vehicle speed VSPa of the right turning vehicle VA.

[0178] In S615, the controller 101a determines whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than a first predetermined vehicle speed Vth1. The processing proceeds to S616 on the assumption that the notification issuance timing for information presentation has arrived in a case where the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, or the information presentation processing is ended in a case where the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1. The first predetermined vehicle speed Vth1 is a vehicle speed set from the viewpoint of whether or not it is possible to secure a time that is long enough to obtain effectiveness of the notification issuance for information presentation, it is possible to secure such a time at the vehicle speed VSPa that is equal to or less than the first predetermined vehicle speed Vth1 while it is not possible to secure such a time at the vehicle speed VSPa exceeding the first predetermined vehicle speed Vth1. Thus, the controller 101a determines that notification issuance for alarm is to be performed in response to arrival of the right turning vehicle VA at the predicted collision area ACP or the approach of the straight traveling vehicle VB to the predicted collision area ACP in the situation. The first predetermined vehicle speed Vth1 is, for example, 20 km / h.

[0179] In this manner, in a case where the right turning vehicle VA has temporarily been stopped at the stop line SL1 before the intersection CS or has sufficiently decelerated before entering the intersection area ACS and has entered the intersection area ACS at the relatively low vehicle speed VSPa, it is determined that the notification issuance timing for information presentation has arrived in response to detection of such a situation, the processing in and after S616 is performed, and whether or not the notification issuance condition is met is determined in the present embodiment. The notification issuance timing for information presentation is not limited thereto, and it is also possible to set the notification issuance timing for information presentation, without limitation based on the driving state such as the vehicle speed VSPa, in response to the fact that the right turning vehicle VA has entered the intersection area ACS, in other words, the fact that the right turning vehicle VA is located in the intersection area ACS.

[0180] In S616, the controller 101a calculates an intersection arrival distance Db of the straight traveling vehicle VB.

[0181] In S617, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0182] In S618, the controller 101a calculates the information presentation distance Dth1.

[0183] In S619, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the information presentation distance Dth1. The processing proceeds to S620 in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1, or the information presentation processing is ended in a case where the intersection arrival distance Db is greater than the information presentation distance Dth1.

[0184] In S620, notification issuance for information presentation is performed.

[0185] In the flowchart illustrated in Fig. 10, the controller 101a reads various kinds of control information used for the alarm processing for normal notification issuance in S711. The control information read in S711 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0186] In S712, the controller 101a specifies the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map.

[0187] In S713, the controller 101a reads the vehicle speed VSPa of the right turning vehicle VA.

[0188] In S714, the controller 101a determines whether or not the vehicle speed VSPa of the right turning vehicle VA is higher than a second predetermined vehicle speed Vth2. The processing proceeds to S716 in a case where the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2, or the processing proceeds to S715 in a case where the vehicle speed VSPa is equal to or less than the second predetermined vehicle speed Vth2. The second predetermined vehicle speed Vth2 is set to a vehicle speed indicated in a case where the right turning vehicle VA is in a state of traveling at a low speed, for example, in a state of traveling at a reduced speed. The driver of the right turning vehicle VA is determined to be paying sufficient attention to the surrounding situation and other traffic participants when the right turning vehicle VA passes the intersection CS, from the behaviors of the right turning vehicle VA in a case where the vehicle speed VSPa is equal to or less than the second predetermined vehicle speed Vth2. The second predetermined vehicle speed Vth2 is, for example, 5 km / h.

[0189] In S715, the controller 101a reduces the predicted collision area ACP in size. In the present embodiment, the size of the predicted collision area ACP is reduced to the smallest size in the setting and is set to have a diameter that substantially coincides with the lane width W of the straight traveling lane L22 where the straight traveling vehicle VB is traveling.

[0190] In S716, the controller 101a determines whether or not the right turning vehicle VA is located in the predicted collision area ACP. The processing proceeds to S718 in a case where the right turning vehicle VA is located in the predicted collision area ACP, or the processing proceeds to S717 in a case where the right turning vehicle VA is not located in the predicted collision area ACP.

[0191] In S717, the controller 101a determines whether or not the vehicle speed VSPa of the right turning vehicle VA is higher than the first predetermined vehicle speed Vth1. The processing proceeds to S718 in a case where the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1, or the alarm processing is ended in a case where the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1. In a case where the right turning vehicle VA is not located in the predicted collision area ACP and the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, notification issuance for information presentation is performed through information presentation processing (S615 in the flowchart illustrated in Fig. 9).

[0192] In this manner, in a situation in which the right turning vehicle VA has reached the predicted collision area ACP and has already been in the predicted collision area ACP, or the right turning vehicle VA, though being out of the predicted collision area ACP, is traveling at a vehicle speed that is equal to or greater than a specific vehicle speed toward the predicted collision point CPP and is approaching the predicted collision area ACP after entering the intersection area ACS, the controller 101a determines that the notification issuance timing for alarm has arrived in response to detection of such a situation in S714 to S717, performs the processing in and after S718, and determines whether or not the notification issuance condition is met.

[0193] In S718, the controller 101a calculates the intersection arrival distance Db of the straight traveling vehicle V.

[0194] In S719, the controller 101a reads the vehicle speed VSPb of the straight traveling vehicle VB.

[0195] In S720, the controller 101a calculates the alarm distance Dth2.

[0196] In S721, the controller 101a determines whether or not the intersection arrival distance Db of the straight traveling vehicle VB is equal to or less than the alarm distance Dth2. The processing proceeds to S722 in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2, or the alarm processing is ended in a case where the intersection arrival distance Db is longer than the alarm distance Dth2.

[0197] In S722, the controller 101a performs the notification issuance for alarm.

[0198] Although the notification issuance for information presentation performed at the time of early notification issuance and the notification issuance for information presentation performed at the time of normal notification issuance can be performed in different manners, they are performed in the similar manner (with the same display and sound, for example) in the present embodiment. The same applies to the notification issuance for alarm, the notification issuance may be performed in the same manner both at the time of the early notification issuance and at the time of normal notification issuance or may be performed in different manners.(Content of notification control in straight traveling vehicle)

[0199] The controller 101b executes the notification control every predetermined time in a case where the intersection CS is detected in a road in front of the host vehicle (that is, the straight traveling vehicle VB). The execution cycles of the notification control may be the same or different between the controller 101a and the controller 101b. Furthermore, both the controllers 101a and 101b can also perform the notification control in a synchronized manner.

[0200] The processes executed by the controller 101a and the controller 101b in relation to the notification control correspond to each other. Thus, the notification control performed by the controller 101b will be described with reference to the flowcharts illustrated in Figs. 4 to 10.

[0201] The controller 101b reads various kinds of control information used for notification control after the notification control is started (S111 illustrated in the flowchart in Fig. 4), detects another vehicle that is present in the right turn lane L11 which is an opposite lane, that is, the right turning vehicle VA (S112), and determines whether or not the right turn intention of the right turning vehicle VA has been detected (S113). In a case where a right turn intention is detected, the controller 101b reads the vehicle speed VSPb of the straight traveling vehicle VB which is a host vehicle, reads the vehicle speed VSPa of the right turning vehicle VA, and sets determination areas (the intersection area ACS and the predicted collision area ACP) on the basis of the vehicle speeds VSPa and VSPb (S116). Similarly to the above description, the controller 101b sets the expanded intersection area ACSe with a relatively large radius φacs in a case where the vehicle speed VSPa is higher than a predetermined vehicle speed, or sets the basic intersection area ACSb with a smaller radius φacs than the relatively large radius φacs in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed. Then, the controller 101b performs the early notification issuance processing (5118) in a case where the expanded intersection area ACSe is set, or performs the normal notification issuance processing (S119) in the other case.

[0202] In the early notification issuance processing, the controller 101b reads various kinds of control information (S211 illustrated in the flowchart in Fig. 5), then specifies the current position Pa of the right turning vehicle VA on the road map (S212), and determines whether or not the right turning vehicle VA has entered the expanded intersection area ACSe (S213). The controller 101b continues the processing and performs the information presentation processing and the alarm processing (S214, S215) in a case where the right turning vehicle VA has entered the expanded intersection area ACSe, or ends this control in a case where the right turning vehicle VA has not entered the expanded intersection area ACSe. Here, in a case where the controller 101b receives a signal indicating that the controller 101a has performed the pedestrian caution notification issuance, the controller 101b performs notification issuance to promote the driver to pay attention to the other vehicle (that is, the right turning vehicle VA). The notification issuance is notification issuance to promote the driver to recognize that the right turning vehicle VA may stop before the crosswalk PC3 after the right turn, that is, in front of the host vehicle in the traveling direction, for example. The information presentation processing and the alarm processing are repeatedly performed until the right turning vehicle VA passes the expanded intersection area ACSe (S219).

[0203] In the information presentation processing for early notification issuance, the controller 101b reads various kinds of control information (S311 illustrated in the flowchart in Fig. 6), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S312). The controller 101b determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP (S313), calculates the intersection arrival distance Db of the straight traveling vehicle VB (S314), calculates the information presentation distance Dth1 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB (S315, S316) in a case where the right turning vehicle VA is determined to be located outside the predicted collision area ACP, and performs the notification issuance for information presentation (S318) in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S317).

[0204] In the alarm processing for early notification issuance, the controller 101b reads various kinds of control information (S411 illustrated in the flowchart in Fig. 7), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map(S412). The controller 101b determines whether or not the right turning vehicle VA is located in the predicted collision area ACP (S413), calculates the intersection arrival distance Db of the straight traveling vehicle VB (S414) and calculates the alarm distance Dth2 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB (S415, S416) in a case where the right turning vehicle VA is determined to be located in the predicted collision area ACP, and performs the notification issuance for alarm (S418) in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S417).

[0205] In the normal notification issuance processing, the controller 101b reads various kinds of control information (S511 illustrated in the flowchart in Fig. 8), then specifies the current position Pa of the right turning vehicle VA on the road map(S512), and determines whether or not the right turning vehicle VA has entered the basic intersection area ACSb (S513). The processing is continued and the information presentation processing and the alarm processing are performed (S514, S515) in a case where the right turning vehicle VA has entered the basic intersection area ACSb, or this control is ended in a case where the right turning vehicle VA has not entered the basic intersection area ACSb. Similarly to the above description, in a case where the controller 101b has received a signal indicating that the controller 101a has performed the pedestrian caution notification issuance, the controller 101b performs notification issuance to promote the driver to pay attention to the other vehicle (that is, the right turning vehicle VA). The information presentation processing and the alarm processing are repeatedly performed until the right turning vehicle VA passes the basic intersection area ACSb (S519).

[0206] In the information presentation processing for normal notification issuance, the controller 101b reads various kinds of control information (S611 illustrated in the flowchart in Fig. 9), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S612). The controller 101b determines whether or not the right turning vehicle VA is located outside the predicted collision area ACP (S613), reads the vehicle speed VSPa of the right turning vehicle VA in a case where the right turning vehicle VA is determined to be located outside the predicted collision area ACP (S614), and determines whether or not the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1 (S615). The controller 101b calculates the intersection arrival distance Db of the straight traveling vehicle VB (S616) and calculates the information presentation distance Dth1 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB (S617, S618) in a case where the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, and performs the notification issuance for information presentation (S620) in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S619).

[0207] In the alarm processing for normal notification issuance, the controller 101b reads various kinds of control information (S711 illustrated in the flowchart in Fig. 10), and then specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S712). The controller 101b reads the vehicle speed VSPa of the right turning vehicle VA (S713), and determines whether or not the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2 (S714). The controller 101b maintains the predicted collision area ACP at a size that has already been set in a case where the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2, or reduces the predicted collision area ACP in size in a case where the vehicle speed VSPa is equal to or less than the second predetermined vehicle speed Vth2 (S715). The intersection arrival distance Db of the straight traveling vehicle VB is calculated (S718) and the alarm distance Dth2 in accordance with the vehicle speed VSPb of the straight traveling vehicle VB is calculated (S719, S720) in a case where the right turning vehicle VA is located in the predicted collision area ACP (S716) or the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1 even if the right turning vehicle VA is located outside the predicted collision area ACP (S717), and the notification issuance for alarm is performed (S722) in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S721).(Description of actions and effects)

[0208] The vehicle notification system 1 according to the present embodiment has the aforementioned configuration. Effects obtained by the present embodiment will be described below.

[0209] Firstly, in a situation where the right turning vehicle VA and the straight traveling vehicle VB face each other with the intersection CS interposed therebetween, the right turn intention of the right turning vehicle VA is detected, notification issuance timings in accordance with the relative positional relationship between the right turning vehicle VA and the intersection CS, that is, the notification issuance timings for information presentation and alarm are then set, and the notification issuance for information presentation or alarm is performed for the traffic participants including the right turning vehicle VA and the straight traveling vehicle VB under the condition that the notification issuance condition defined in regard to the position of the straight traveling vehicle VB is met at these notification issuance timings. This makes it possible to realize notification issuance in an appropriate mode at an appropriate timing in accordance with the degree of urgency of the situation where there is a concern that the right turning vehicle VA and the straight traveling vehicle VB may collide against each other.

[0210] Then, the intersection CS or the predetermined area around the intersection CS, in the present embodiment, the intersection surrounding area AAC is monitored, and in a case where a pedestrian who is a subject of surveillance to be monitored is detected in the intersection surrounding area AAC, notification issuance to promote the right turning vehicle VA to pay attention to the pedestrian, that is, the pedestrian caution notification issuance is performed. It is thus possible to promote the right turning vehicle VA to pay attention to the subject of surveillance that may be present at the intersection CS and the surroundings thereof other than the straight traveling vehicle VB, such as the pedestrian crossing the crosswalk PS3 around the intersection CS, and to avoid contact of the right turning vehicle VA with the subject of surveillance in a situation where attention is likely to be paid to the straight traveling vehicle VB in the opposite lane L22.

[0211] Here, it is possible to avoid contact with the subject of surveillance at the crosswalk PC3 after the right turn, which is likely to occur when the right turning vehicle VA passes the intersection CS, by setting the intersection surrounding area AAC including the crosswalk on the side further forward than the intersection center CTR in the traveling direction of the right turning vehicle VA, that is, the crosswalk PC3 after the right turn as the area where the subject of surveillance or a pedestrian is to be detected.

[0212] Secondly, the intersection area ACS is set, the notification issuance timing is set after the right turning vehicle VA enters the intersection area ACS, the notification issuance for information presentation or alarm is performed under the condition that the straight traveling vehicle VB is located at the notification issuance execution distance Dth1, Dth2 from the intersection CS or is located at a position closer to the intersection CS than the notification issuance execution distance Dth1, Dth2 while the pedestrian caution notification issuance is performed in response to detection of a pedestrian in the intersection surrounding area AAC in a case where the notification issuance condition is not met because the straight traveling vehicle VB is located at a position farther from the intersection CS than the notification issuance execution distance Dth1, Dth2, and it is thus possible to perform the pedestrian caution notification issuance at the timing at which the straight traveling vehicle VB is located at a position far from the intersection CS or the notification issuance for information presentation or alarm at the timing at which the straight traveling vehicle VB approaches the intersection CS, for the right turning vehicle VA that is present in the intersection area ACS.

[0213] In this manner it is possible to switch the mode for the notification issuance in accordance with the position of the straight traveling vehicle VB and to realize notification issuance in an appropriate mode in accordance with the situation for the right turning vehicle VA that is present in the intersection area ACS. Specifically, it is possible to promote the right turning vehicle VA to pay attention to the pedestrian by performing the pedestrian caution notification issuance when the straight traveling vehicle VB is located at a position far from the intersection CS and the degree of urgency of the situation in regard to collision against the right turning vehicle VA is low, and to promote the right turning vehicle VA to recognize that the straight traveling vehicle VB is approaching by switching the mode for notification issuance to the information presentation or the alarm in a case where the straight traveling vehicle VB has approached the intersection CS and the degree of urgency has increased.

[0214] Thirdly, the predicted collision area ACP is set, the pedestrian caution notification issuance is performed using different sound or different sound and display in a case where the right turning vehicle VA is traveling at the vehicle speed VSPa that is higher than the predetermined vehicle speed Vth1 toward the predicted collision point CPP outside the predicted collision area ACP or is located in the predicted collision area ACP and in the other case, and it is thus possible to perform the pedestrian caution notification issuance in a mode in accordance with the degree of urgency of the situation in regard to contact with the subject of surveillance, such as the pedestrian crossing the crosswalk PC3 after the right turn.

[0215] Fourthly, the expanded intersection area ACSe is set in a case where the vehicle speed VSPa of the right turning vehicle VA traveling toward the intersection CS is higher than the predetermined vehicle speed after detection of a right turn intention, the pedestrian caution notification issuance is performed in a case where a pedestrian is detected in the intersection surrounding area AAC after the right turning vehicle VA enters the expanded intersection area ACSe, and it is thus possible to perform the pedestrian caution notification issuance at an earlier timing as compared with a case where the vehicle speed VSPa of the right turning vehicle VA is lower than the predetermined vehicle speed. It is thus possible to promote the right turning vehicle VA traveling toward the intersection CS while maintaining a relatively high vehicle speed to recognize the presence of the pedestrian at an earlier timing and to decelerate sufficiently before the crosswalk PC3 after the right turn.

[0216] Also, it is possible to cause the right turning vehicle VA to temporarily stop before reaching the predicted collision area ACP and to reduce situations where the right turning vehicle VA interrupts passage of the straight traveling vehicle VB by promoting the right turning vehicle VA to decelerate at an earlier timing.

[0217] Furthermore, the notification issuance to promote the straight traveling vehicle VB to pay attention to the right turning vehicle VA is performed in addition to the pedestrian caution notification issuance in a case where a pedestrian is detected in the intersection surrounding area AAC in the present embodiment. In other words, in a case where a pedestrian is detected, the notification issuance to promote attention to the pedestrian is performed for the right turning vehicle VA, while the notification issuance to promote recognition of the presence of the right turning vehicle VA that may stop in front of the crosswalk PC3 after the right turn in response to the execution of the pedestrian caution notification issuance is performed for the straight traveling vehicle VB. This makes it possible not only to avoid contact of the right turning vehicle VA with the pedestrian but also to avoid collision of the straight traveling vehicle VB against the right turning vehicle VA stopped in front of the crosswalk PC3 in response to the pedestrian caution notification issuance.

[0218] In the notification system 1 according to the present embodiment, the notification issuance in the first mode and the notification issuance in the second mode are performed with different sounds via the speaker 141a of the HMI device 131a in the right turning vehicle VA. In other words, the content of notification read in the notification issuance in the first mode and the content of notification read in the notification issuance in the second mode are different from each other. Each of the content of notification in the notification issuance in the first mode and the content of notification in the notification issuance in the second mode is configured of a relatively short sentence, for example. Therefore, the driver of the right turning vehicle VA can understand the content of notification in a short period of time without his / her driving being hindered. In other words, the driver of the right turning vehicle VA can easily identify the notification issuance in the first mode and the notification issuance in the second mode from the difference in sounds, that is, the difference in content of notifications by the sounds. Therefore, the notification system 1 can allow the driver in a situation where the driver is focusing on his / her front side for driving to more accurately recognize, with different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode without hindering the driving.

[0219] Furthermore, in the notification system 1 according to the present embodiment, the notification issuance in the first mode and the notification issuance in the second mode are further performed through different displays in the right turning vehicle VA. As illustrated in Fig. 22, the content of notification displayed in the notification issuance in the first mode is limited to the information indicating the type and the traveling direction (straight traveling direction) of the counterpart vehicle (straight traveling vehicle VB), and as illustrated in Fig. 23, the content of notification displayed in the notification issuance in the second mode is limited to the information PE indicating the presence of the object to be monitored, which are minimum necessary information. Therefore, the notification system 1 can make it easy for the driver of the right turning vehicle VA to easily understand the content of these notifications. Moreover, it is possible to cause the content of the notifications to be displayed by illustration and text with relatively large sizes, for example, by limiting the content of these notifications to minimum necessary information. Therefore, the notification system 1 can improve visibility of the driver by causing the content of the notifications to be displayed by illustration and text with relatively large sizes. In other words, the driver can easily understand the content of the notifications merely by glancing at the display 143a of the HMI device 131a while focusing on the front side. Therefore, the notification system 1 can allow the driver of the right turning vehicle VA to more accurately recognize, on the basis of the different displays in addition to the different sounds, whether the target to which attention is to be paid is the straight traveling vehicle VB based on the notification issuance in the first mode or the object to be monitored based on the notification issuance in the second mode without hindering the driving.

[0220] In the present embodiment, the notification issuance in the first mode is implemented with different sounds depending on whether the right turning vehicle VA is present in the expanded intersection area ACSe or in the basic intersection area ACSb. In this manner, the driver of the right turning vehicle VA can recognize the straight traveling vehicle VB, which is the target to which attention is to be paid, in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Therefore, the notification system 1 can prompt the driver of the right turning vehicle VA to execute a safer action to avoid collision against the straight traveling vehicle VB at the timing at which the right turning vehicle VA arrives at the intersection CS. Additionally, the driver of the straight traveling vehicle VB can recognize the right turning vehicle VA that is the target to which attention is to be paid in the stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Thus, the notification system 1 can prompt the driver of the straight traveling vehicle VB to execute a safer action to avoid collision against the right turning vehicle VA just in case the right turning vehicle VA tries to turn right at the intersection CS before the straight traveling vehicle VB passes the intersection CS.

[0221] In the notification system 1 according to the present embodiment, the notification issuance in the second mode is performed with different sounds in a case where the right turning vehicle VA is present in the expanded intersection area ACSe and in a case where the right turning vehicle VA is present in the basic intersection area ACSb. In this manner, the driver of the right turning vehicle VA can recognize the object to be monitored that is a target to which attention is to be paid in a stage where the right turning vehicle VA is present in the expanded intersection area ACSe to cause the distance before arrival at the intersection CS to become relatively long, which leads to extra time. Therefore, the notification system 1 can prompt the driver of the right turning vehicle VA to execute a safer action to avoid collision against the target to be monitored at the timing at which the right turning vehicle VA reaches the intersection CS.

[0222] In the notification system 1 according to the present embodiment, the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB are performed with the same sound. Therefore, the notification system 1 can allow the driver of the straight traveling vehicle VB to pay attention only to the right turning vehicle VA to which it is necessary to pay attention even in a case where the object to be monitored to which it is not necessary for the driver of the straight traveling vehicle VB to pay attention to is detected at the intersection CS or in the intersection surrounding area AAC, which is a predetermined area around the intersection CS, when the straight traveling vehicle VB passes the intersection CS. Therefore, the notification system 1 can provide a notification that does not hinder the driving of the driver of the straight traveling vehicle VB.

[0223] In the notification system 1 according to the present embodiment, the notification issuance in the third mode and the notification issuance in the first mode in the straight traveling vehicle VB are performed through the same display in addition to the same sound. Therefore, the notification system 1 can reliably provide a notification that does not hinder the driving of the driver of the straight traveling vehicle VB.

[0224] The notification system 1 according to the present embodiment includes the first notification issuing unit B118a and the third notification issuing unit B122a that perform notification issuance in the fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects an object to be monitored when the notification issuance in the first mode as notification issuance for information presentation is being performed. Furthermore, the notification system 1 includes the second notification issuing unit B119a and the third notification issuing unit B122a that performs the notification issuance in the fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound via the HMI device 131a in the right turning vehicle VA in a case where the pedestrian detection unit B121a detects an object to be monitored when the notification issuance in the first mode as notification issuance for alarm is being performed. Therefore, the notification system 1 can make the driver of the right turning vehicle VA aware of the presence of the pedestrian by the notification issuance in the fourth mode based on the sound and to promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm.

[0225] In the notification system 1 according to the present embodiment, the notification issuance in the fourth mode is further performed through display. Therefore, the notification system 1 can make the driver of the right turning vehicle VA aware of the presence of the pedestrian by the notification issuance in the fourth mode based on the display in addition to the sound and to reliably promote the driver to decelerate or temporarily stop before the crosswalk PC3 in a case where the driver of the right turning vehicle VA has advanced in the intersection CS and has approached the crosswalk PC3 without noticing the notification issuance for information presentation or by ignoring the notification issuance for information presentation and the notification issuance for alarm.

[0226] In the notification system 1 according to the present embodiment, the notification issuance at least with a sound is performed until a predetermined word, a predetermined phrase, or a predetermined sentence representing the content of the notification is read at least once or more in a case where completion of passing of the right turning vehicle VA through the intersection CS is detected on the basis of a result of specification by the road map storage unit B113a when the notification issuance at least with a sound is being performed. Therefore, the notification system 1 can avoid the content of the notification ending in the middle and allow the driver to more accurately understand the content of the notification.(Other embodiments)

[0227] The notification issuance processing may be performed under a condition that the right turning vehicle VA and the straight traveling vehicle VB are in a situation where they face each other with the intersection CS interposed therebetween. Specifically, the execution of the notification issuance processing is avoided in a case where it is expected that the straight traveling vehicle VB passes the intersection CS before the right turning vehicle VA enters the intersection CS or the right turning vehicle VA passes the intersection CS before the straight traveling vehicle VB approaches the intersection CS.

[0228] Fig. 20 illustrates, as an example, a situation where the straight traveling vehicle VB passes the intersection CS before the right turning vehicle VA enters the intersection CS. In the present embodiment, the execution of the notification issuance processing is avoided in a case where the illustrated situation is expected at the timing when the right turn intention of the right turning vehicle VA is detected.

[0229] Specifically, an intersection entry clock time ta1 at which the right turning vehicle VA reaches an intersection entry point P1a in the lane L11 where the right turning vehicle VA is traveling is compared with an intersection exit clock time tb2 at which the straight traveling vehicle VB reaches an intersection exit point P2b in the lane L22 where the straight traveling vehicle VB is traveling, and the execution of the notification issuance processing is avoided in a case where the intersection entry clock time ta1 of the right turning vehicle VA is later than the intersection exit clock time tb2 of the straight traveling vehicle VB. Both the intersection entry point P1a of the right turning vehicle VA and the intersection exit point P2b of the straight traveling vehicle VB can be set on the outer edge of the intersection area ACS (for example, the basic intersection area ACSb), and the intersection entry clock time ta1 can be calculated on the basis of the road map information and the current position Pa and the vehicle speed VSPa of the right turning vehicle VA, while the intersection exit clock time tb2 can be calculated on the basis of the road map information and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0230] In a simplified manner, the intersection entry clock time ta1 of the right turning vehicle VA can be calculated by Equation (6.1) below using a distance Da1 from the current position Pa to the intersection center CTR at the timing (clock time t0) at which the right turn intention is detected and the radius φacs of the intersection area ACS, while the intersection exit clock time tb2 of the straight traveling vehicle VB can be calculated by Equation (6.2) below using a distance Db1 from the current position Pb to the intersection center CTR at the timing at which the right turn intention of the right turning vehicle VA is detected and the radius φacs of the intersection area ACS. ta 1 = t 0 + Da 1 − φacs / VSPa tb 2 = t 0 + Db 1 − φacs / VSPb

[0231] Fig. 21 illustrates, as an example, a situation where the right turning vehicle VA passes the intersection CS before the straight traveling vehicle VB reaches the notification issuance position. In the present embodiment, the execution of the notification issuance processing is avoided in a case where the illustrated situation is expected as well at the timing at which the right turn intention of the right turning vehicle VA is detected, in addition to the situation mentioned earlier.

[0232] Specifically, an intersection leaving clock time ta2 at which the right turning vehicle VA reaches the exit point P2a from the intersection CS is compared with a notification issuance position arrival clock time tb1 at which the straight traveling vehicle VB reaches a point (hereinafter, referred to as a "notification issuance execution point") P1b at a predetermined notification issuance distance from the intersection CS, and the execution of the notification issuance processing is avoided in a case where the notification issuance position arrival clock time tb1 is later than the intersection leaving clock time ta2. The intersection exit point P2a of the right turning vehicle VA can be set on the outer edge of the intersection area ACS (for example, the basic intersection area ACSb), and the notification issuance execution point P1b of the straight traveling vehicle VB can be set at a point at the information presentation distance Dth1 from the intersection CS, for example, a point at the information presentation distance Dth1 from the outer edge of the predicted collision area ACP. The intersection leaving clock time ta2 can be calculated on the basis of the road map information and the current position Pa and the vehicle speed VSPa of the right turning vehicle VA, while the notification issuance position arrival clock time tb1 can be calculated on the basis of the road map information and the current position Pb and the vehicle speed VSPb of the straight traveling vehicle VB.

[0233] In a simplified manner, the intersection leaving clock time ta2 of the right turning vehicle VA can be calculated by Equation (7.1) below using a distance Da1 from the current position Pa to the intersection center CTR at the timing (clock time t0) at which the right turn intention is detected and the radius φacs of the intersection area ACS, while the notification issuance position arrival clock time tb1 of the straight traveling vehicle VB can be calculated by Equation (7.2) below using a distance Db2 from the current position Pb to the predicted collision area ACP at the timing at which the right turn intention of the right turning vehicle VA is detected and the information presentation distance Dth1. ta 2 = t 0 + Da 1 − φacs / VSPa tb 1 = t 0 + Db 2 − Dth 1 / VSPb

[0234] Fig. 19 is a flowchart illustrating an overall flow of notification control according to the present embodiment. In the present embodiment, the notification control can be realized as control that executes the processes illustrated in S811 to S817 in addition to the process illustrated in each step in the flowchart in Fig. 4.

[0235] Differences of a case where the notification control is performed by the controller 101a of the right turning vehicle VA from the flowchart in Fig. 4 will be mainly described. The controller 101a reads various kinds of control information used for the notification control (S111), then detects the straight traveling vehicle VB which is another vehicle in the opposite lane L22 (S112), and if a right turn intention of the right turning vehicle VA which is a host vehicle is detected (S113), the controller 101a calculates the intersection entry clock time ta1 and the intersection leaving clock time ta2 of the right turning vehicle VA in S811.

[0236] In S812, the controller 101a calculates the notification issuance position arrival clock time tb1 and the intersection exit clock time tb2 of the straight traveling vehicle VB.

[0237] In S813, the controller 101a determines whether or not the intersection entry clock time ta1 of the right turning vehicle VA is later than the intersection exit clock time tb2 of the straight traveling vehicle VB. The processing proceeds to S815 in a case where the intersection entry clock time ta1 is later than the intersection exit clock time tb2, or the processing proceeds to S814 in a case where the intersection entry clock time ta1 is before the intersection exit clock time tb2.

[0238] In S814, the controller 101a determines whether or not the notification issuance position arrival clock time tb1 of the straight traveling vehicle VB is later than the intersection leaving clock time ta2 of the right turning vehicle VA. The processing proceeds to S815 in a case where the notification issuance position arrival clock time tb1 is later than the intersection leaving clock time ta2, or the processing illustrated in S114 to S119 surrounded by the frame A of the two-dotted chain line in Fig. 4 is performed in a case where the notification issuance position arrival clock time tb1 is before the intersection leaving clock time ta2.

[0239] In S815, the controller 101a determines whether or not a subject of surveillance to be monitored has been detected at the intersection CS and in the predetermined area around the intersection CS, for example, whether a pedestrian has been detected in the intersection surrounding area AAC. The processing proceeds to S816 in a case where a pedestrian has been detected, or this control is ended in a case where no pedestrians have been detected.

[0240] In S816, the controller 101a performs notification issuance to promote the right turning vehicle VA to pay attention to the pedestrian, that is, pedestrian caution notification issuance.

[0241] In S817, the controller 101a notifies the straight traveling vehicle VB of the fact that the pedestrian caution notification issuance has been performed for the right turning vehicle VA. This promotes the straight traveling vehicle VB to recognize that the right turning vehicle VA that may stop before the crosswalk PC3 after the right turn in response to the execution of the pedestrian caution notification issuance is present in a situation where the execution of the notification issuance processing in the processes in S114 to S119 illustrated in the flowchart in Fig. 4 is avoided.

[0242] In this manner, although the execution of the notification issuance processing leads to an increase in computational loads on the controllers 101a and 101b required for the monitoring of the right turning vehicle VA and the straight traveling vehicle VB (tracking of the current positions Pa and Pb and the like), it is possible to reduce unnecessary execution of the notification issuance processing and an accompanying increase in computational loads and to effectively use the computational capacities of the controllers 101a and 101b by allocating a generated margin to other control, by avoiding the execution of the notification issuance processing in a case where the right turning vehicle VA and the straight traveling vehicle VB are not in a situation where they face each other with the intersection CS interposed therebetween.

[0243] Also, the intersection leaving clock time ta2 of the right turning vehicle VA and the notification issuance position arrival clock time tb1 of the straight traveling vehicle VB are predicted, the pedestrian caution notification issuance is performed for the right turning vehicle VA in response to detection of a pedestrian in the intersection surrounding area AAC and the straight traveling vehicle VB is notified of the fact that the pedestrian caution notification issuance has been performed for the right turning vehicle VA in a case where the notification issuance position arrival clock time tb1 is later than the intersection leaving clock time ta2, and it is thus possible to cause the straight traveling vehicle VB to recognize the presence of the right turning vehicle VA that may stop before the crosswalk PC3 after the right turn in response to the execution of the pedestrian caution notification issuance and to reduce situations where the straight traveling vehicle VB collides against the right turning vehicle VA.

[0244] In the above description, the pedestrian caution notification issuance is performed after the right turning vehicle VA enters the intersection area ACS (the expanded intersection area ACSe, the basic intersection area ACSb). The pedestrian caution notification issuance can also be performed before the right turning vehicle VA enters the intersection area ACS. Fig. 18 is a schematic diagram illustrating a positional relationship between the right turning vehicle VA and the straight traveling vehicle VB at a timing at which the pedestrian caution notification issuance is performed as an example of such a case.

[0245] As illustrated in Fig. 18, the pedestrian caution notification issuance can also be performed at a timing before the right turning vehicle VA reaches the intersection area ACS. For example, the controller 101a performs the pedestrian caution notification issuance without waiting for the entry to the intersection area ACS in a case where a pedestrian is detected in the intersection surrounding area AAC by a signal from a smartphone that the pedestrian has after the right turning vehicle VA displays its intention to turn right at the intersection CS by operating a right turn signal or entering a right turn only lane.

[0246] In this manner, the notification issuance timing is set after the right turning vehicle VA enters the intersection area ACS, the notification issuance for information presentation or alarm is performed when the notification issuance condition in regard to the position of the straight traveling vehicle VB is met while the pedestrian caution notification issuance is performed at a timing before the right turning vehicle VA enters the intersection area ACS, and it is thus possible to cause the right turning vehicle VA to pay attention to the pedestrian before entering the intersection area ACS and to promote the right turning vehicle VA to decelerate at an early timing before or after the entry to the intersection area ACS and temporarily stop at or near the position of the entry to the intersection CS. This makes it possible to more reliably avoid contact of the right turning vehicle VA with the pedestrian and to further reduce situations where the right turning vehicle VA interrupts passage of the straight traveling vehicle VB by the right turning vehicle VA stopping before the crosswalk PC3 after the right turn.

[0247] In the above description, the distance from the outer edge of the predicted collision area ACP, specifically, the intersecting point between the traveling path TRb of the straight traveling vehicle VB and the circle (the circles illustrated by the dashed lines in the drawings) defining the outer edge of the predicted collision area ACP to the straight traveling vehicle VB is employed as the distance Db from the intersection CS to the straight traveling vehicle VB. The distance Db is not limited thereto, and the distance from the predicted collision point CPP to the straight traveling vehicle VB may be employed, or the distance along the center line of the opposite lane L22 from the right turning vehicle VA to the straight traveling vehicle VB may be employed, as the distance Db.

[0248] Although the controllers 101a and 101b included in the right turning vehicle VA and the straight traveling vehicle VB, respectively constitute the calculation unit of the notification system 1 and the controllers 101a and 101b constitute one virtual controller, a configuration in which roadside equipment or a remote server is caused to have the road map and a computer program for the notification control and is caused to perform the notification control outside the vehicles may also be adopted. In this case, the right turning vehicle VA and the straight traveling vehicle VB transmit position information of the respective vehicles to the external controller through road-to-vehicle communication and receive command signals which are results of calculation related to control. Then, the notification issuance for the information presentation or the alarm is executed on the basis of the command signals.

[0249] The traffic participants as targets of the notification issuance are not limited to the right turning vehicle VA and the straight traveling vehicle VB and may be any other vehicles that are approaching the intersection CS. It is possible to exemplify, as such vehicles, a vehicle traveling toward the intersection CS (that is, a crossing vehicle) in a lane other than the right turn lane L11 and lanes extending in parallel to the right turn lane L11 (for example, the straight traveling lane L12), specifically, a crossing lane L31 intersecting the right turn lane L11 from among lanes leading to the intersection CS to which the right turning vehicle VA is directed. Here, a vehicle other than the right turning vehicle VA that is approaching the intersection CS and may potentially enter the intersection CS is referred to as an "intersection entering vehicle". The intersection entering vehicle may include not only the straight traveling vehicle VB but also a crossing vehicle.

[0250] In the road illustrated in Figure 12, in a case where a crossing vehicle (not shown) is present in addition to or instead of the straight traveling vehicle VB as an intersection entering vehicle, and when there is no traffic signal installed at the intersection CS to regulate the movement of the crossing vehicle, there is a concern that the timing of the crossing vehicle entering the intersection CS may coincide with that of the right turning vehicle VA, potentially resulting in contact or collision between these vehicles.

[0251] In such a situation, the notification system 1 monitors the relative positional relationship between the right turning vehicle VA and the crossing vehicle after detecting the right turn intention of the right turning vehicle VA, and similarly to the above description, the notification issuance in accordance with urgency of the situation related to contact or collision between the right turning vehicle VA and the crossing vehicle is executed at an appropriate timing before the right turning vehicle VA passes the intersection CS after approaching the intersection CS. As an example, the right turning vehicle VA and the crossing vehicle perform information presentation processing and alarm processing similar to those that the right turning vehicle VA and the straight traveling vehicle VB execute between these vehicle VA and VB.

[0252] The intersection surrounding area AAC is monitored, and when a subject of surveillance such as a pedestrian is detected in the intersection surrounding area AAC, a notification issuance to promote attention to the subject of surveillance or the right turning vehicle VA is performed for the crossing vehicle. This enables the crossing vehicle to recognize the presence of a pedestrian at the crosswalk PC3 after the right turn, and encourages the crossing vehicle to decelerate before entering the intersection CS. Consequently, it is possible to prevent situations in which the right turning vehicle VA is promoted to temporarily stop before the crosswalk PC3 by the notification issuance to call for attention and obstruct the path of the host vehicle, or the crossing vehicle, and contact or collision occurs between these vehicles.

[0253] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.REFERENCE SIGNS LIST

[0254] 1vehicle notification system 101a, 101bcontroller 111a, 111bposition sensor 112a, 112bvehicle speed sensor 113a, 113bright turn signal switch 121a, 121btransmitter 122a, 122breceiver 131a, 131bhuman machine interface device (HMI device) VAright turning vehicle VBstraight traveling vehicle ACSintersection area ACPpredicted collision area AACintersection surrounding area

Examples

Embodiment Construction

[0013]Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same reference signs are given to identical or equivalent components in each figure.

(Overall Configuration of Vehicle Notification System)

[0014]Fig. 1 is a schematic diagram illustrating a configuration of a vehicle notification system (hereinafter, simply referred to as a "notification system" in some cases) 1 according to an embodiment of the present invention.

[0015]In the present embodiment, a traffic situation where a vehicle (hereinafter, referred to as a "right turning vehicle") VA traveling toward an intersection on a left-hand traffic road and another vehicle (hereinafter, referred to as a "straight traveling vehicle") VB traveling in a straight direction toward the intersection in a lane (hereinafter, referred to as an "opposite lane" in some cases) opposite to a lane (hereinafter, referred to as a "traveling lane" in some cases) in which the right turning...

Claims

1. A vehicle notification system (1) that performs notification issuance at least with sounds for traffic participants including a first vehicle (VA) that is present in a traveling lane (L11) leading to an intersection (CS) to turn right or left at the intersection (CS) and a second vehicle (VB) that travels in a straight traveling direction toward the intersection (CS) in a lane (L22) opposite to the traveling lane (L11), the vehicle notification system (1) comprising: a monitored object detection unit (B121a) that detects an object to be monitored that is movable in a sidewalk at the intersection (CS) or in a predetermined area around the intersection (CS); a first notification issuing unit (B118a, B118b, B119a, B119b) that performs notification issuance in a first mode to avoid collision between the first vehicle (VA) and the second vehicle (VB); and a second notification issuing unit (B122a) that performs notification issuance in a second mode for the first vehicle (VA) to avoid collision between the first vehicle (VA) and the object to be monitored that has been detected by the monitored object detection unit (B121a), wherein the notification issuance in the first mode and the notification issuance in the second mode are performed with mutually different sounds in the first vehicle (VA).

2. The vehicle notification system (1) according to claim 1, wherein the notification issuance in the first mode and the notification issuance in the second mode are further performed by mutually different displays in the first vehicle (VA).

3. The vehicle notification system (1) according to claim 1 or 2, further comprising: a vehicle speed detection unit (112a, B115b) that detects a vehicle speed of the first vehicle (VA); and a determination area setting unit (B120a, B120b) that sets an intersection area (ACS) that overlaps a path (TRa) where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS), before the first vehicle (VA) reaches the intersection (CS), wherein the determination area setting unit (B120a, B120b) sets an expanded intersection area (ACSe) by expanding the intersection area (ACS) in a direction spaced apart from the intersection (CS) toward the traveling lane (L11) where the first vehicle (VA) is present, in a case where the vehicle speed of the first vehicle (VA) detected by the vehicle speed detection unit (112a, B115b) is higher than a predetermined vehicle speed, and the notification issuance in the first mode is performed with different sounds in a case where the first vehicle (VA) is present in the expanded intersection area (ACSe) and in a case where the first vehicle (VA) is present in the intersection area (ACS) other than the expanded intersection area (ACSe).

4. The vehicle notification system (1) according to any one of claims 1 to 3, further comprising: a vehicle speed detection unit (112a, B115b) that detects a vehicle speed of the first vehicle (VA); and a determination area setting unit (B120a, B120b) that sets an intersection area (ACS) that overlaps a path (TRa) where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS), before the first vehicle (VA) reaches the intersection (CS), wherein the determination area setting unit (B120a, B120b) sets an expanded intersection area (ACSe) by expanding the intersection area (ACS) in a direction spaced apart from the intersection toward the traveling lane (L11) where the first vehicle (VA) is present, in a case where the vehicle speed of the first vehicle (VA) detected by the vehicle speed detection unit (112a, B115b) is higher than a predetermined vehicle speed, and the notification issuance in the second mode is performed with different sounds in a case where the first vehicle (VA) is present in the expanded intersection area (ACSe) and in a case where the first vehicle (VA) is present in the intersection area (ACS) other than the expanded intersection area (ACSe).

5. The vehicle notification system according to any one of claims 1 to 4, further comprising: a third notification issuing unit (B122a, 121a) that performs notification issuance in a third mode to promote the second vehicle (VB) to pay attention to the first vehicle (VA), in a case where the second notification issuing unit (B122a, 121a) performs the notification issuance in the second mode, wherein the notification issuance in the third mode and the notification issuance in the first mode in the second vehicle (VB) are performed by a same sound.

6. The vehicle notification system (1) according to claim 5, wherein the notification issuance in the third mode and the notification issuance in the first mode in the second vehicle (VB) are performed through same display.

7. The vehicle notification system (1) according to any one of claims 1 to 6, wherein the first notification issuing unit (B118a, B118b, B119a, B119b) and the second notification issuing unit (B122a) perform notification issuance in a fourth mode, which is different from the notification issuance in the first mode and the notification issuance in the second mode, with a sound in the first vehicle (VA), in a case where the monitored object detection unit (B121a) detects the object to be monitored when the notification issuance in the first mode is being performed.

8. The vehicle notification system (1) according to claim 7, wherein the notification issuance in the fourth mode is further performed through display.

9. The vehicle notification system (1) according to any one of claims 1 to 8, comprising: a road map storage unit (B113a, B113b) that stores a road map including the intersection (CS) and specifies a current position of the first vehicle (VA) on the road map and a current position of the second vehicle (VB) on the road map, wherein in a case where completion of passing of the first vehicle (VA) through the intersection (CS) is detected on the basis of a result of specification by the road map storage unit (B113a, B113b) when the notification issuance at least with a sound is being performed, the notification issuance at least with a sound is performed until a predetermined word, a predetermined phrase, or a predetermined sentence is read at least once or more.

Images