Vehicle notification system

Abstract

The vehicle notification system sets a notification issuance timing in accordance with a relative position of a right turning vehicle VA to an intersection CS in a traffic situation where the right turning vehicle VA and a straight traveling vehicle VB are approaching the intersection CS from opposite directions. The system calculates a notification issuance distance Dth1, Dth2 on the basis of a preset deceleration rate DEC1, DEC2 as a distance required for deceleration of the straight traveling vehicle VB, and performs notification issuance in a predetermined mode in a case where the straight traveling vehicle VB is located at the notification issuance distance DEC1, DEC2 from the intersection CS or is located at a position closer to the intersection CS than the notification issuance distance at the notification issuance timing.

Description

BACKGROUND OF THE INVENTIONField of the Invention

[0001] The present invention relates 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.Citation ListPatent Document

[0004] Patent Document 1: Japanese Patent Laid-Open No. 2009-265832

[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.SUMMARY OF THE INVENTION

[0008] Thus, an object of the present invention is to provide a vehicle notification system that contributes to a further improvement in traffic safety.

[0009] To solve the above-mentioned problem, a vehicle notification system according to one aspect of the present invention is configured to perform notification issuance for traffic participants including a first vehicle that is present in a lane leading to an intersection and turns right or left at the intersection and a second vehicle that travels in a straight direction toward the intersection in a lane opposite to the lane where the first vehicle is present.

[0010] In this aspect, the vehicle notification system may include a notification issuance timing setting unit that sets a notification issuance timing in accordance with a position of the first vehicle relative to the intersection, and a notification issuing unit that performs notification issuance in a predetermined mode for the traffic participants under a condition that a notification issuance condition defined in relation to a position of the second vehicle is met at the notification issuance timing set by the notification issuance timing setting unit.

[0011] The notification issuing unit may be configured to calculate a notification issuance distance on the basis of a preset deceleration rate as a distance required for deceleration of the second vehicle, and perform notification issuance in the predetermined mode in a case where the second vehicle is located at the notification issuance distance from the intersection or is located at a position closer to the intersection than the notification issuance distance at the notification issuance timing.

[0012] The vehicle notification system may further include a relative vehicle speed detection unit that detects a vehicle speed of the second vehicle relative to the first vehicle.

[0013] In this case, the notification issuing unit may be configured to calculate the notification issuance distance on the basis of the deceleration rate and the relative vehicle speed of the second vehicle.

[0014] The vehicle notification system may further include a first vehicle speed detection unit that detects a vehicle speed of the first vehicle and a second vehicle speed detection unit that detects a vehicle speed of the second vehicle.

[0015] In this case, the notification issuing unit calculates the notification issuance distance on the basis of the deceleration rate and the relative vehicle speed of the second vehicle when the vehicle speed of the first vehicle detected by the first vehicle speed detection unit is higher than a predetermined vehicle speed, or calculates the notification issuance distance on the basis of the deceleration rate and the vehicle speed of the second vehicle detected by the second vehicle speed detection unit when the vehicle speed of the first vehicle is lower than the predetermined vehicle speed.

[0016] The notification issuing unit may be configured to switch the deceleration rate in accordance with a vehicle speed of the first vehicle to calculate the notification issuance distance.

[0017] In this case, the vehicle notification system preferably includes a vehicle speed detection unit that detects a vehicle speed of the first vehicle.

[0018] The notification issuing unit may be configured to switch the deceleration rate in accordance with a vehicle speed of the second vehicle or a relative vehicle speed of the second vehicle to calculate the notification issuance distance.

[0019] In this case, for switching the deceleration rate, the vehicle notification system preferably includes a vehicle speed detection unit that detects a vehicle speed of the second vehicle and / or a relative vehicle speed detection unit that detects a vehicle speed of the second vehicle relative to the first vehicle.

[0020] The notification issuing unit may be configured to switch the deceleration rate between a case where the vehicle speed of the first vehicle is higher than the predetermined vehicle speed and a case where the vehicle speed of the first vehicle is lower than the predetermined vehicle speed to calculate the notification issuance distance.

[0021] In this case, the notification issuing unit may be configured to cause the deceleration rate to be lower in a case where the vehicle speed of the first vehicle is higher than the predetermined vehicle speed than in a case where the vehicle speed of the first vehicle is lower than the predetermined vehicle speed.

[0022] Regarding a point at which a path where the first vehicle travels when the first vehicle passes the intersection and a path where the second vehicle travels when the second vehicle passes the intersection intersect as a predicted collision point, the notification issuance timing setting unit may be configured to set, as the notification issuance timings, a first notification issuance timing and a second notification issuance timing at which the first vehicle is located at a position closer to the predicted collision point as compared with the first notification issuance timing, and the notification issuing unit may be configured to perform notification issuance in the predetermined mode under a condition that the notification issuance condition is met at each of the first notification issuance timing and the second notification issuance timing set by the notification issuance timing setting unit.

[0023] In this case, the notification issuance condition at the first notification issuance timing may include occurrence of a situation where the second vehicle is located at a first notification issuance distance from the intersection or is located at a position closer to the intersection than the first notification issuance distance, and the notification issuance condition at the second notification issuance timing may include occurrence of a situation where the second vehicle is located at a second notification issuance distance, which is shorter than the first notification issuance distance, from the intersection or is located at a position closer to the intersection than the second notification issuance distance.

[0024] Further, the notification issuing unit may be configured to have, as the deceleration rates, a first predetermined deceleration rate and a second predetermined deceleration rate that is higher than the first predetermined deceleration rate, and calculate the first notification issuance distance on the basis of the first predetermined deceleration rate and calculate the second notification issuance distance on the basis of the second predetermined deceleration rate.

[0025] The notification issuing unit may be configured to calculate the notification issuance distance on the basis of a distance obtained by adding a predetermined brake reaction distance to a deceleration distance in accordance with the deceleration rate.

[0026] According to an aspect of the present invention, a notification issuance timing in accordance with the position of a right turning vehicle relative to an intersection is set in a situation where the right turning vehicle and a straight traveling vehicle face each other with the intersection sandwiched therebetween. Here, the notification issuance distance is calculated on the basis of a preset deceleration rate, and notification issuance in a predetermined mode is performed in a case where the straight traveling vehicle is located at the notification issuance distance from the intersection or is located at a position closer to the intersection than the notification issuance distance. It is thus possible to perform notification issuance at a timing that corresponds to driver's sensation (driving feeling) when the straight traveling vehicle decelerates in response to the notification issuance, thereby to suppress a situation where inconsistency between the driver's sensation and the timing of performing the notification issuance causes anxiety of the driver, and to allow for more appropriate notification issuance.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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 information presentation processing; Fig. 6 is a flowchart illustrating content of information presentation distance calculation processing; Fig. 7 is a flowchart illustrating content of alarm processing; Fig. 8 is a flowchart illustrating content of alarm distance calculation processing; Fig. 9 is an explanatory diagram illustrating a method of calculating an information presentation distance and an alarm distance (based on a vehicle speed of the straight traveling vehicle); Fig. 10 is an explanatory diagram illustrating a method of calculating an information presentation distance and an alarm distance (based on a relative vehicle speed of the straight traveling vehicle); Fig. 11 is an explanatory diagram illustrating changes in deceleration rates DEC1, DEC2 in accordance with a vehicle speed or a relative vehicle speed of the right turning vehicle; 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 an issuance timing of information presentation (under low-speed driving condition of the right turning vehicle); Fig. 14 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at an issuance timing of an alarm (under low-speed driving condition of the right turning vehicle); Fig. 15 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at an issuance timing of information presentation (under high-speed driving condition of the right turning vehicle); Fig. 16 is a schematic diagram illustrating a relationship between the right turning vehicle and the straight traveling vehicle at an issuance timing of an alarm (under high-speed driving condition of the right turning vehicle); Fig. 17 is a schematic diagram illustrating a situation after the straight traveling vehicle passes an intersection; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings.(Overall Configuration of Vehicle Notification System)

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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. 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 high-precision satellite positioning 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).

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The notifications may be provided by the HMI devices 131a and 131b visually or auditorily. The HMI devices 131a and 131b can provide both display and sound notifications and can also provide notifications using one of them. 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.

[0044] In addition to the above, 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.

[0045] 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.

[0046] Fig. 12 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a notification target according to the present embodiment.

[0047] 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.

[0048] In addition to the right turning vehicle VA and the straight traveling vehicle VB, a vehicle (hereinafter, referred to as a "waiting vehicle") VZ 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 VZ 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 VZ 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 VZ seen from the straight traveling vehicle VB.

[0049] 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 (hereinafter, simply referred to as "right turn intention"). Then, the notification system 1 issues a notification in accordance with a degree of urgency of circumstances related to contact or 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.(Internal Configuration of Controller)

[0050] 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 mentioned earlier as needed.

[0051] 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 vehicle speed detection unit B115a, a first vehicle behavior detection unit B116a, a second vehicle behavior detection unit B117a, a first notification issuing unit B118a, and a second notification issuing unit B119a. A function of each of these units B111a to B119a 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.

[0052] 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 of the host vehicle 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.

[0053] 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 of another vehicle 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.

[0054] 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 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 to correspond to the 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.

[0055] 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.

[0056] The vehicle speed detection unit B115a detects the vehicle speed VSPb of the straight traveling vehicle VB. The vehicle speed detection unit B115a detects the vehicle speed VSPb of the straight traveling vehicle VB (that is, another vehicle) 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.

[0057] The first vehicle behavior detection unit B116a detects that the right turning vehicle VA is present at a first predetermined position P1 in the lane (that is, the right turn lane L11) where the right turning vehicle VA is traveling or at a position closer to a center position (hereinafter, referred to as an "intersection center") CTR of the intersection CS than the first predetermined position P1 after the right turn intention detection unit B114a detects the right turn intention on the basis of the current position Pa of the right turning vehicle VA on the road map, in other words, after the right turning vehicle VA displays its right turn intention by entering the right turn lane L11 or operating the right turn signal.

[0058] 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 to 17, which will be described later).

[0059] 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 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 first predetermined position P1 in the right turn lane L11 or the position closer to the intersection center CTR than the first predetermined position P1 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 first vehicle behavior detection unit B116a sets the timing at which the arrival of the right turning vehicle VA at the intersection area ACS or entrance thereof into the intersection area ACS is detected as a first notification issuance timing. The first notification issuance timing set by the first vehicle behavior detection unit B116a is the timing at which the right turning vehicle VA performs notification issuance in a first predetermined mode. The intersection area ACS is set as a circular area that includes the first predetermined position P1 on its outer edge concentrically with the intersection center CTR. Figs. 13 to 17 illustrate 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.

[0060] The second vehicle behavior detection unit B117a regards, as a "predicted collision point" CPP, a point at which the path TRa along which the right turning vehicle VA travels when passing the intersection CS and the path TRb along which the straight traveling vehicle VB travels when passing the intersection CS intersect and detects, on the basis of the current position Pa of the right turning vehicle VA on the road map, that the right turning vehicle VA is traveling at a position closer to the predicted collision point CPP than the first predetermined position P1 toward the predicted collision point CPP or that the right turning vehicle VA is present at a position closer to the predicted collision point CPP than a second predetermined position P2 between the first predetermined position P1 and the predicted collision point CPP.

[0061] 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.

[0062] 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 traveling of the right turning vehicle VA at a position closer to the predicted collision point CPP than the first predetermined position P1 or presence of the right turning vehicle VA at a position closer to the predicted collision point CPP than the second predetermined position P2 is detected on the basis of the right turning vehicle VA traveling toward the predicted collision point CPP inside the intersection area ACS or being present inside the predicted collision area ACP after entering the intersection area ACS. The second vehicle behavior detection unit B117a sets the timing at which the right turning vehicle VA traveling toward the predicted collision point CPP inside the intersection area ACS or being present inside the predicted collision area ACP is detected as a second notification issuance timing. The second notification issuance timing set by the second vehicle behavior detection unit B117a is a timing at which the right turning vehicle VA performs notification issuance in a second predetermined mode. The predicted collision area ACP is set as a circular area that includes the second predetermined position P2 on its outer edge and has a smaller area than the intersection area ACS.

[0063] 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 and SL2 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).

[0064] The first notification issuing unit B118a outputs a command signal to issue a notification in a first predetermined mode 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 timing at which presence of the right turning vehicle VA at the first predetermined position P1 in the right turn lane L11 or a position closer to the intersection center CTR than the first predetermined position P1 is detected, or the first notification issuance timing. In the present embodiment, the issuance of a command signal from the first notification issuing unit B118a to the HMI device 131a constitutes the execution of a notification issuance in the first predetermined mode.

[0065] 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.

[0066] 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 using display and 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.

[0067] The second notification issuing unit B119a outputs a command signal to issue a notification in a second predetermined mode 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 timing at which traveling of the right turning vehicle VA at a position closer to the predicted collision point CPP than the first predetermined position P1 or presence of the right turning vehicle VB at a position closer to the predicted collision point CPP than the second predetermined position P2 is detected, or the second notification issuance timing. In the present embodiment, the issuance of a command signal from the second notification issuing unit B119a to the HMI device 131a constitutes the execution of a notification issuance in the second predetermined mode.

[0068] 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.

[0069] The notification issuance in the second predetermined mode is notification issuance in a mode that is different from the first predetermined mode, and 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 using display and sound. The notification issuance performed by the second notification issuing unit B119a is notification issuance that is more prominent and more visually or auditorily appealing to the driver as compared with the notification issuance performed by the first notification issuing unit B118a.

[0070] 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).

[0071] 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.

[0072] 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 vehicle speed detection unit B115b, a first vehicle behavior detection unit B116b, a second vehicle behavior detection unit B117b, a first notification issuing unit B118b, and a second notification issuing unit B119b. Differences between an internal configuration of the controller 101b and that of the controller 101a will be mainly described below.

[0073] 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 thereof is based on an output signal from the position sensor 111b included in the straight traveling vehicle VB.

[0074] 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 thereof 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.

[0075] 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.

[0076] The right turn intention detection unit B114b is adapted to detect a right turn intention of the right turning vehicle VA, and the detection thereof 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.

[0077] The vehicle speed detection unit B115b is adapted to detect the vehicle speed VSPa of the right turning vehicle VA, and the detection thereof 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 that is included in the straight traveling vehicle VB.

[0078] The first vehicle behavior detection unit B116b detects that the right turning vehicle VA is located at a predetermined relative position with reference to the first predetermined position P1 relative to the intersection CS after showing its right turn intention. Specifically, the first vehicle behavior detection unit B116b compares the current position Pa of the right turning vehicle VA on the road map 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 vehicle behavior detection unit B116b sets the detected timing as a first notification issuance timing. The first notification issuance timing set by the first vehicle behavior detection unit B116b is a timing at which the straight traveling vehicle VB performs notification issuance in a first predetermined mode.

[0079] 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 size of the intersection area ACS to be variable or to change the shape thereof in accordance with a drivers' selection or trends of driving states at the time of passing the intersection CS, for example.

[0080] The second vehicle behavior detection unit B117b monitors a behavior of the right turning vehicle VA after the right turning vehicle VA enters the intersection CS and detects that the right turning vehicle VA is traveling toward the predicted collision point CPP in the intersection area ACS or is present inside the predicted collision area ACP after entering the intersection area ACS. And then, the second vehicle behavior detection unit B117b sets the detected timing as a second notification issuance timing. The second notification issuance timing set by the second vehicle behavior detection unit B117b is a timing at which the straight traveling vehicle VB performs notification issuance in a second predetermined mode.

[0081] 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 preset as default coordinates on the road map, 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.

[0082] The first notification issuing unit B118b outputs a command signal to issue the notification in the first predetermined mode 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 a timing at which the arrival of the right turning vehicle VA at the intersection area ACS or entrance thereof to the intersection area ACS is detected, or the first notification issuance timing. 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. The issuance of a command signal from the first notification issuing unit B118b to the HMI device 131b constitutes the execution of a notification issuance in the first predetermined mode.

[0083] 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 using display and 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.

[0084] The second notification issuing unit B119b outputs a command signal to issue a notification in the second predetermined mode 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 a timing at which traveling of the right turning vehicle VA toward the predicted collision point CPP in the intersection area ACS or presence thereof inside the predicted collision area ACP is detected, or the second notification issuance timing. 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. The issuance of a command signal from the second notification issuing unit B119b to the HMI device 131b constitutes the execution of a notification issuance in the second predetermined mode.

[0085] 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 using display and sound. Similarly to the above description, the notification issuance performed by the second notification issuing unit B119a is also notification issuance that is more prominent and more visually or auditorily appealing to the driver.

[0086] 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.

[0087] Figs. 9 and 10 are explanatory diagrams illustrating a method of calculating the information presentation distance Dth1 and the alarm distance Dth2.

[0088] In the present embodiment, the information presentation distance Dth1 and the alarm distance Dth2 each correspond to the "notification issuance distance," where the information presentation distance Dth1 corresponds to the "first notification issuance distance," and the alarm distance Dth2 corresponds to the "second notification issuance distance".

[0089] The first notification issuing unit B118a of the controller 101a and the first notification issuing unit B118b of the controller 101b read the vehicle speeds VSPa and VSPb of the right turning vehicle VA and the straight traveling vehicle VB, respectively, to calculate the information presentation distance Dth1. Then, the second notification issuing unit B119a of the controller 101a and the second notification issuing unit B119b of the controller 101b read the vehicle speeds VSPa and VSPb of the right turning vehicle VA and the straight traveling vehicle VB, respectively, to calculate the alarm distance Dth2.

[0090] Although the vehicle speeds at the first and second notification issuance timings are adopted as the vehicle speeds VSPa and VSPb of the vehicles VA and VB used for calculating the notification issuance distance, that is, the information presentation distance Dth1 which is the first notification issuance distance and the alarm distance Dth2 which is the second notification issuance distance, it is also possible to adopt the vehicle speeds at the first notification issuing timing as the vehicle speeds VSPa and VSPb in a simplified manner.

[0091] In the present embodiment, the vehicle speed VSPb of the straight traveling vehicle VB used for calculating the notification issuance distance is switched between an absolute vehicle speed VSPb (hereinafter, the simply referred "vehicle speed" means the absolute vehicle speed) and a relative vehicle speed RSPb in accordance with the vehicle speed VSPa of the right turning vehicle VA. Here, the relative vehicle speed RSPb is a speed (= VSPa + VSPb) of the straight traveling vehicle VB relative to the right turning vehicle VA.

[0092] Specifically, the relative vehicle speed RSPb of the straight traveling vehicle VB is adopted for calculating the notification issuance distances Dth1 and Dth2 when the vehicle speed VSPa of the right turning vehicle VA is higher than a predetermined vehicle speed Vth1, or the vehicle speed VSPb of the straight traveling vehicle VB is adopted when the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1. In the present embodiment, the predetermined vehicle speed Vth1 is a speed at which it is expected that sensation received by the driver from approach of the counterpart vehicle, in other words, sensation that the distance from the host vehicle to the other vehicle is reduced substantially increases, and it is possible to appropriately select and set the predetermined vehicle speed Vth1 by a sensory evaluation test and the like. The predetermined vehicle speed Vth1 is, for example, 20 km / h.

[0093] In a case where the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1, 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 from the current vehicle speed VSPb, in other words, a distance required by the straight traveling vehicle VB to stop after notification issuance on the basis of the vehicle speed VSPb of the straight traveling vehicle VB and deceleration rates DEC1 and DEC2 set in advance in accordance with the notification issuance mode.

[0094] As illustrated in Fig. 9, the information presentation distance Dth1 is calculated by adding distances by which the straight traveling vehicle VB is expected to travel in a brake 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. The brake 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 brake reaction time PRD1 is set in advance as a constant time (= ΔT). The deceleration time PRD2 is a time required by the vehicle to stop after the brake starts to actually work and can be calculated on the basis of the vehicle speed VSPb and the deceleration rate DEC1 (PRD2 = VSPb / DEC1). Specifically, the calculation of the information presentation distance Dth1 is based on Equation (1.1) below. Dth 1 = VSPb × ΔT + VSPb × VSPb / DEC 1 / 2

[0095] Although the alarm distance Dth2 is similarly calculated by adding the distance by which the straight traveling vehicle VB is expected to travel in each of the brake reaction time PRD1 and the deceleration time PRD2, the deceleration rate DEC2 which is different from that used to calculate the information presentation distance Dth1 is adopted. The deceleration rate DEC2 for calculating the alarm distance is a higher deceleration rate than the deceleration rate DEC1 for calculating the information presentation distance, in other words, a deceleration rate having a larger absolute value than that of the deceleration rate DEC1 (|DEC1| < |DEC2|). Specifically, this calculation is based on Equation (2.1) below. Dth 2 = VSPb × ΔT + VSPb × VSPb / DEC 2 / 2

[0096] In contrast, in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1, the information presentation distance Dth1 and the alarm distance Dth2 are calculated as distances by which the straight traveling vehicle VB is expected to travel before stopping when the relative vehicle speed RSPb is assumed to be a vehicle speed after the notification issuance on the basis of the relative vehicle speed RSPb of the straight traveling vehicle VB and the deceleration rates DEC1 and DEC2 set in advance in accordance with the notification issuance mode. In the present embodiment, the deceleration rates DEC1 and DEC2 used for calculating the notification issuance distance are the same both in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1 and in a case where the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1. It is possible to exemplify DEC1 = -0.1G and DEC2 = -0.2G as the deceleration rates DEC1 and DEC2 that can be adopted.

[0097] As illustrated in Fig. 10, the information presentation distance Dth1 is calculated by adding the distances by which the straight traveling vehicle VB is expected to travel in the brake reaction time PRD1 and the deceleration time PRD2 on the basis of the relative vehicle speed RSPb (= V2) of the straight traveling vehicle VB at the first notification issuance timing. The brake reaction time PRD1 is set in advance as the constant time (= ΔT), and the deceleration time PRD2 can be calculated on the basis of the relative vehicle speed RSPb and the deceleration rate DEC1 (PRD2 = RSPb / DEC1). Specifically, the calculation of the information presentation distance Dth1 is based on Equation (1.2) below. Dth 1 = RSPb × ΔT + RSPb × RSPb / DEC 1 / 2

[0098] Similarly, the alarm distance Dth2 is also calculated by adding the distances by which the straight traveling vehicle is expected to travel in the brake reaction time PRD1 and the deceleration time PRD2 on the basis of the relative vehicle speed RSPb and the deceleration rate DEC2 of the straight traveling vehicle VB. Specifically, the calculation is based on Equation (2.2) below. Dth 2 = RSPb × ΔT + RSPb × RSPb / DEC 2 / 2

[0099] The information presentation distance Dth1 and the alarm distance Dth2 may be set to equal distances between the controller 101a and the controller 101b or may be set to different distances therebetween. In a case where the information presentation distance Dth1 and the alarm distance Dth2 are set to different distances, at least one of the deceleration rates DEC1 and DEC2 is caused to be different between the right turning vehicle VA and the straight traveling vehicle VB, for example. For example, the intensity of the sensation that the driver of the counterpart vehicle feels in response to the approach of the traveling vehicle is considered to be higher for the driver of the straight traveling vehicle VB than for the driver of the right turning vehicle VA, and at least one of the deceleration rates DEC1 and DEC2 that the controller 101b has is thus set to be a larger value than the deceleration rates DEC1 and DEC2 that the controller 101a has.(Content of Notification Control in Right Turning Vehicle)

[0100] Figs. 4 to 8 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 flowchart in Figs. 5 and 6 illustrate content of processing (information presentation processing) executed by the right turning vehicle VA in regard to information presentation, and the flowchart in Figs. 7 and 8 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).

[0101] In the flowchart illustrated in Fig. 4, various kinds of control information used for the notification control is read 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, and the current position Pb, the vehicle speed VSPb, and the link ID of the straight traveling vehicle VB. 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.

[0102] In S112, whether or not the right turning vehicle VA which is the host vehicle has detected another vehicle traveling in the straight direction toward the intersection CS in the lane opposite to the lane in which the right turning vehicle VA is present, that is, the straight traveling vehicle VB is determined. The detection of the straight traveling vehicle VB is based on the link ID of 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.

[0103] In S113, whether or not a right turn intention of the right turning vehicle VA has been detected is determined. 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. In a case where the right turn lane L11 is a lane only for right turn, for example, the right turn intention of the right turning vehicle VA may also be detected by the fact that the lane where the right turning vehicle VA is traveling is the right turn lane L11. 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.

[0104] In S114, the current position Pa of the right turning vehicle VA on the road map is specified.

[0105] In S115, whether or not the right turning vehicle VA has entered the intersection area ACS is determined. Specifically, in a case where the right turning vehicle VA is located at a position of the outer edge of the intersection area ACS (that is, the first predetermined position P1) or is located at a position closer to the intersection center CTR than the position of the outer edge, it is determined that the right turning vehicle VA has entered the intersection area ACS, and the processing proceeds to S116. 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 intersection area ACS, the right turning vehicle VA is determined not to have arrived at the intersection area ACS and to be located outside the intersection area ACS, and this control is ended.

[0106] In S116, the information presentation processing is performed. The information presentation processing follows a procedure illustrated in the flowchart in Fig. 5.

[0107] In S117, the alarm processing is performed. The alarm processing follows a procedure illustrated in the flowchart in Fig. 7.

[0108] In S118, whether or not the right turning vehicle VA has passed the intersection CS is determined. The determination of whether or not the right turning vehicle VA has passed the intersection CS is made based on the fact that the right turning vehicle VA has left the intersection area ACS in the traveling direction after turning right. This control is ended in a case where the right turning vehicle VA has passed the intersection CS, or the processing returns to S116 to repeat the information presentation processing and the alarm processing until the right turning vehicle VA passes the intersection CS in a case where the right turning vehicle VA has not passed the intersection CS and is still in the intersection area ACS.

[0109] In the flowchart illustrated in Fig. 5, various kinds of control information used for the information presentation processing is read 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.

[0110] In S212, the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map are specified.

[0111] In S213, whether or not the right turning vehicle VA is located outside the predicted collision area ACP is determined. Specifically, in a case where the right turning vehicle VA is located between the position of the outer edge of the intersection area ACS and the position of the outer edge of the predicted collision area ACP (that is, the second predetermined position P2), the right turning vehicle VA is determined to be located outside the predicted collision area ACP, and the processing proceeds to S214. In a case where the operating status of the right turn signal is used to detect the right turn intention of the right turning vehicle VA, whether or not the operation of the right turn signal is being continued may be determined in addition to the processing in S213, and the processing in and after S214 may be performed in a case where the operation of the right turn signal is being continued. 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.

[0112] In S214, the vehicle speed VSPa of the right turning vehicle VA is read.

[0113] In S215, whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than a predetermined vehicle speed VSP1 is determined. The predetermined vehicle speed VSP1 is a low speed that is low enough to determine that the right turning vehicle VA is in a low-speed traveling state and is a reduced speed (specifically, 10 km / hour), for example. In the present embodiment, it is determined that the driver of the right turning vehicle VA is paying attention to the surrounding situation to pass the intersection CS by the fact that the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1. The processing proceeds to S216 in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1, or the information presentation processing is ended in a case where the vehicle speed VSPa is greater than the vehicle speed VSP1. The predetermined vehicle speed VSP1 may be 0 km / hour, and in other words, S215 may be processing of determining whether or not the right turning vehicle VA has temporarily stopped inside the intersection area ACS. Furthermore, it is also possible to eliminate the processing in S215 itself, and the notification issuance for the alarm may be prioritized over the notification issuance for the information presentation in a case where a notification issuance condition for the information presentation (S218) and the notification issuance condition for the alarm (S318) mentioned later are established at the same time.

[0114] In this manner, in a case where the right turning vehicle VA has maintained the low vehicle speed VSPa until the arrival at the predicted collision area ACP or has sufficiently decelerated (including the case of temporarily stopping) after entering the intersection area ACS, it is determined that a notification issuance timing for the information presentation has arrived on the basis of the detection of the vehicle speed VSPa that is equal to or less than the predetermined vehicle speed VSP1, the processing in and after S216 is performed, and whether or not the first predetermined notification issuance condition has been established is determined in the present embodiment.

[0115] In S216, 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") is calculated. 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, and the calculation is based on the current position Pb of the straight traveling vehicle VB.

[0116] In S217, the information presentation distance Dth1 is calculated. The calculation of the information presentation distance Dth1 is based on the vehicle speed VSPb and the relative vehicle speed RSPb of the straight traveling vehicle VB and the first predetermined deceleration degree DEC1 in accordance with the procedure illustrated in the flowchart of Fig. 6.

[0117] In S218, 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 is determined. The processing proceeds to S219 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.

[0118] In S219, the notification issuance for the information presentation is performed.

[0119] In the flowchart illustrated in Fig. 6, the vehicle speed VSPa of the right turning vehicle VA, which is a host vehicle, is read in S217a.

[0120] In S217b, whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1 is determined. The processing proceeds to S217c in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed Vth1, or the processing proceeds to S217e in a case where the vehicle speed VSPa is higher than the predetermined vehicle speed Vth1.

[0121] In S217c, the vehicle speed VSPb of the straight traveling vehicle VB, which is another vehicle, is read.

[0122] In S217d, the information presentation distance Dth11 is calculated using Equation (1.1) above on the basis of the vehicle speed VSPb of the straight traveling vehicle VB and the first predetermined deceleration rate DEC1.

[0123] In S217e, the vehicle speed VSPb of the straight traveling vehicle VB is read.

[0124] In S217f, the vehicle speed RSPb of the straight traveling vehicle VB relative to the right turning vehicle VA is calculated.

[0125] In S217g, the information presentation distance Dth12 is calculated using Equation (1.2) above on the basis of the relative vehicle speed RSPb and the first predetermined deceleration rate DEC1 of the straight traveling vehicle VB. Here, the information presentation distance Dth12 calculated using the relative vehicle speed RSPb of the straight traveling vehicle VB is longer than the information presentation distance Dth11 (Fig. 13) calculated using the vehicle speed VSPb as illustrated in Fig. 15.

[0126] In the flowchart illustrated in Fig. 7, various kinds of control information used for the alarm processing is read 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.

[0127] In S312, the current positions Pa and Pb of the right turning vehicle VA and the straight traveling vehicle VB on the road map are specified.

[0128] In S313, whether or not the right turning vehicle VA is located inside the predicted collision area ACP is determined. Specifically, in a case where the right turning vehicle VA is located at the position of the outer edge of the predicted collision area ACP (that is, the second predetermined position P2) or is located at the position closer to the predicted collision point CPP than the position of the outer edge, the right turning vehicle VA is determined to be located inside the predicted collision area ACP, and the processing proceeds to S316. 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 processing proceeds to S314. In a case where the operating status of the right turn signal is used to detect the right turn intention of the right turning vehicle VA, the fact that the operation of the right turn signal is being continued may be included as a condition of performing the processing as a premise of performing the processing in S313.

[0129] In S314, the vehicle speed VSPa of the right turning vehicle VA is read.

[0130] In S315, whether or not the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed VSP1 is determined. The processing proceeds to S316 in a case where the vehicle speed VSPa is greater than the predetermined vehicle speed VSP1, or the alarm processing is ended in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1. In other words, whether or not the vehicle speed VSPa of the right turning vehicle VA is greater than the vehicle speed VSP1 achieved in the low-speed traveling state, for example, a speed reduced state is determined, and in a case where the vehicle speed VSPa is greater than the vehicle speed VSP1, the driver of the right turning vehicle VA is determined not to be paying attention to the surrounding situation, and the processing proceeds to S316. On the other hand, in a case where the vehicle speed VSPa is equal to or less than the vehicle speed VSP1, it is determined that the notification should be issued for the information presentation in the situation, and the alarm processing is ended.

[0131] In this manner, a notification issuance timing for an alarm is determined to have arrived on the basis of detection of a situation in which the right turning vehicle VA has arrived at the predicted collision area ACP and has already been in the predicted collision area ACP after entering the intersection area ACS or the right turning vehicle VA is traveling at a speed that is equal to or greater than a specific speed toward the predicted collision point CPP even outside the predicted collision area ACP and is approaching the predicted collision area ACP in S313 to S315, the processing in and after S316 is performed, and whether or not the second predetermined notification issuance condition is established is determined.

[0132] In S316, the intersection arrival distance Db of the straight traveling vehicle VB is calculated.

[0133] In S317, the alarm distance Dth2 is calculated. The calculation of the alarm distance Dth2 is based on the vehicle speed VSPb and the relative vehicle speed RSPb of the straight traveling vehicle VB and the second predetermined deceleration degree DEC2 in accordance with the procedure illustrated in the flowchart of Fig. 8.

[0134] In S318, 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 is determined. The processing proceeds to S319 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.

[0135] In S319, the notification issuance for the alarm is performed.

[0136] In the flowchart illustrated in Fig. 8, the vehicle speed VSPa of the right turning vehicle VA, which is a host vehicle, is read in S317a.

[0137] In S317b, whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1 is determined. The processing proceeds to S317c in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed Vth1, or the processing proceeds to S317e in a case where the vehicle speed VSPa is higher than the predetermined vehicle speed Vth1.

[0138] In S317c, the vehicle speed VSPb of the straight traveling vehicle VB, which is another vehicle, is read.

[0139] In S317d, the alarm distance Dth21 is calculated using Equation (2.1) above on the basis of the vehicle speed VSPb and the second predetermined deceleration rate DEC2 of the straight traveling vehicle VB.

[0140] In S317e, the vehicle speed VSPb of the straight traveling vehicle VB is read.

[0141] In S317f, the vehicle speed RSPb of the straight traveling vehicle VB relative to the right turning vehicle VA is calculated.

[0142] In S317g, the alarm distance Dth22 is calculated using Equation (2.2) above on the basis of the relative vehicle speed RSPb and the second predetermined deceleration rate DEC2 of the straight traveling vehicle VB. Here, the alarm distance Dth22 calculated using the relative vehicle speed RSPb of the straight traveling vehicle VB is longer than the alarm distance Dth21 (Fig. 14) calculated using the vehicle speed VSPb as illustrated in Fig. 16.(Content of notification control in straight traveling vehicle)

[0143] Processes executed by the controller 101a and the controller 101b in relation to the notification control correspond to each other. Thus, differences of the notification control performed by the controller 101b from the control performed by the controller 101a will be mainly described in the following description with appropriate reference to the flowcharts illustrated in Figs. 4 to 8.

[0144] Once the notification control is started, the controller 101b reads various kinds of control information (S111 illustrated in the flowchart in Fig. 4), and if another vehicle that is present in the right turning lane L11, which is an opposite lane, that is, the right turning vehicle VA is detected (S112), the controller 101b determines whether or not a right turn intention of the right turning vehicle VA has been detected (S113). After the right turn intention is detected, the current position Pa of the right turning vehicle VA on the road map is specified (S114), and whether or not the right turning vehicle VA has entered the intersection area ACS is determined (S115). In a case where the right turning vehicle VA has entered the intersection area ACS, the control is continued, the information presentation processing is performed (S116), and the alarm processing is performed (S117). The information presentation processing and the alarm processing are repeated until the right turning vehicle VA passes the intersection area ACS.

[0145] In the information presentation processing, the controller 101b reads various kinds of control information to be used for the information presentation processing, such as the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA (S211) 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 (S212). Whether or not the right turning vehicle VA is located outside the predicted collision area ACP is determined (S213), and in a case where the right turning vehicle VA is determined to be located outside the predicted collision area ACP, the vehicle speed VSPa of the right turning vehicle VA is read (S214), and whether or not the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1 is determined (S215). In a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1, the processing is continued, the intersection arrival distance Db of the straight traveling vehicle VB is calculated (S216), and the information presentation distance Dth1 is calculated (S217). The calculation of the information presentation distance Dth1 follows a procedure similar to that illustrated in the flowchart in Fig. 6. Here, in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1, and the driver strongly perceives the approach of the counterpart vehicle, the information presentation distance Dth1 is calculated as a distance that is longer than that in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed Vth1 (Dth11 < Dth12) by adopting the relative vehicle speed RSPb. Then, in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S218), the notification issuance for the information presentation is performed (S219).

[0146] In the alarm processing, the controller 101b reads various kinds of control information to be used for the alarm processing, such as the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA (S311) and specifies the current positions Pb and Pa of the straight traveling vehicle VB and the right turning vehicle VA on the road map (S312). Whether or not the right turning vehicle VA is located inside the predicted collision area ACP is determined (S313), and in a case where the right turning vehicle VA is determined not to be located inside the predicted collision area ACP, the vehicle speed VSPa of the right turning vehicle VA is read (S314), and whether or not the vehicle speed VSPa is higher than the predetermined vehicle speed VSP1 is determined (S315). In a case where the vehicle speed VSPa is higher than the predetermined vehicle speed VSP1, the processing is continued, the intersection arrival distance Db of the straight traveling vehicle VB, which is a host vehicle, is calculated (S316), and the alarm distance Dth2 is calculated (S317). The calculation of the alarm distance Dth2 follows a procedure that is similar to that illustrated in the flowchart in Fig. 8. Here, in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1, and the driver strongly perceives the approach of the counterpart vehicle, the alarm distance Dth2 is calculated as a distance that is longer than that in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed Vth1 (Dth21 < Dth22) by adopting the relative vehicle speed RSPb. Then, in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S318), the notification issuance for the alarm is performed (S319).(Description of actions and effects)

[0147] The vehicle notification system 1 according to the present embodiment has the aforementioned configuration. Effects obtained by the present embodiment will be described below.

[0148] Firstly, in a traffic situation where the right turning vehicle VA and the straight traveling vehicle VB face each other with the intersection CS sandwiched therebetween, the notification issuance timing in accordance with the position of the right turning vehicle VA relative to the intersection CS is set, and notification issuance in a predetermined mode is performed under the condition that the notification issuance condition defined in regard to the position of the straight traveling vehicle VB is met at the notification issuance timing. It is thus possible to perform notification issuance in a mode in accordance with a level of urgency of a situation related to contact or collision between the right turning vehicle VA and the straight traveling vehicle VB for the traffic participants including the vehicles VA and VB at an appropriate timing.

[0149] Specifically, in a case where the right turning vehicle VA is located at a position with a relatively long distance left before the predicted collision point CPP and the straight traveling vehicle VB is located at a position sufficiently separated from the intersection CS, notification issuance for the information presentation is performed for a relatively low level of urgency in regard to contact or collision therebetween. On the other hand, in a case where the right turning vehicle VA is continuously traveling at a relatively high vehicle speed even after entering the intersection area ACS or has arrived at the predicted collision area ACP while the straight traveling vehicle VB has also approached a position close to the intersection CS, notification issuance is performed for promoting recognition of a higher level of urgency in regard to collision therebetween.

[0150] Here, at the time of performing the notification issuance, it is possible to perform the notification issuance at a timing that suits driver's sensation (driving feeling) at the time of deceleration by calculating the notification issuance distances Dth1 and Dth2 on the basis of the preset deceleration rates (that is, the first predetermined deceleration rate DEC1 and the second predetermined deceleration rate DEC2) and performing the notification issuance in the predetermined mode in a case where the straight traveling vehicle VB is located at the notification issuance distances Dth1 and Dth2 from the intersection CS or is located at a position closer to the intersection CS than the notification issuance distances Dth1 and Dth2 at the notification issuance timing. This helps to suppress situations where inconsistency between the driver's sensation and the timing at which the notification issuance is performed causes discomfort of the driver or causes anxiety of the driver, allowing for more appropriate notification issuance.

[0151] Secondly, it is possible to further suppress situations where discomfort of the driver is caused or anxiety of the driver is caused by detecting the vehicle speed RSPb of the straight traveling vehicle VB relative to the right turning vehicle VA, calculating the notification issuance distances Dth1 and Dth2 on the basis of the preset deceleration rates DEC1 and DEC2 and the relative vehicle speed RSPb of the straight traveling vehicle VB, reflecting sensation that the driver actually receives in response to the approach of the counterpart vehicle to the notification issuance timing, and setting a timing that further suits the driver's sensation as the timing at which the notification issuance is to be performed.

[0152] If the vehicle speed VSPb of the straight traveling vehicle VB is adopted for the calculation of the notification issuance distances Dth1 and Dth2 in a situation in which the right turning vehicle VA is approaching the intersection CS or the intersection center CTR at the relatively high vehicle speed VSPa, the notification issuance is not performed before the straight traveling vehicle VB reaches a position that is relatively close to the intersection CS regardless of the driver's strong perception of the approach of the counterpart vehicle, and discomfort of the driver may be caused or anxiety of the driver may be caused due to the timing at which the notification issuance is performed. According to the present embodiment, it is possible to suppress a situation where safety is rather lost by the driver who has recognized the presence of the counterpart vehicle by the notification issuance performs a brake operation in a hurry, by enabling the notification issuance to be performed at a more appropriate timing to thereby suppress such a situation.

[0153] Thirdly, it is possible to perform the notification issuance at a more appropriate timing while suppressing adverse effects of adopting the relative vehicle speed RSPb, such as excessively long notification issuance distances Dth1 and Dth2 leading to carelessness of the driver who receives the notification issuance, by enabling the vehicle speed to be used for calculating the notification issuance distances Dth1 and Dth2 to be switched between the absolute vehicle speed VSPb and the relative vehicle speed RSPb in accordance with the vehicle speed VSPa of the right turning vehicle VA and adopting the relative vehicle speed RSPb of the straight traveling vehicle VB in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1 while adopting the vehicle speed VSPb (that is, the absolute vehicle speed) of the straight traveling vehicle VB in a case where the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1.

[0154] Fourthly, it is possible to perform notification issuance at each timing in an appropriate mode in accordance with a level of urgency of a situation regarding contact or collision between the right turning vehicle VA and the straight traveling vehicle VB by setting, as the notification issuance timings, the first notification issuance timing and the second notification issuance timing at which the right turning vehicle VA is located at a position closer to the predicted collision point CPP as compared with the first notification issuance timing and performing notification issuance in a predetermined mode under a condition that the notification issuance condition regarding the position of the straight traveling vehicle VB is met at each of the first and second notification issuance timings.

[0155] Here, it is possible to perform notification issuance at an appropriate timing in accordance with purposes such as information presentation and alarm by including, in the notification issuance condition at the first notification issuance timing, the fact that 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, including, in the notification issuance condition at the second notification issuance timing, the fact that the straight traveling vehicle VB is located at the alarm distance Dth2 from the intersection CS or is located closer to the intersection CS than the alarm distance Dth2, and further calculating the information presentation distance Dth1 and the alarm distance Dth2 on the basis of the mutually different deceleration rates DEC1 and DEC2.

[0156] Fifthly, it is possible to more reliably secure a time required by the driver to take a necessary measure in response to the notification issuance by calculating the notification issuance distances Dth1 and Dth2 on the basis of the distances obtained by adding the brake reaction distances to the deceleration distances in accordance with the deceleration rates DEC1 and DEC2.

[0157] In the above description, the deceleration rates DEC1 and DEC2 to be used for calculating the notification issuance distances Dth1 and Dth2 are set to the same value in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1 and in a case where the vehicle speed VSPa is lower than the predetermined vehicle speed Vth1 when whether or not the notification issuance condition is met is determined after the setting of the notification issuance timing. The present invention is not limited thereto, and the deceleration rates DEC1 and DEC2 may be mutually differently set in the case where the vehicle speed VSPa is higher than the predetermined vehicle speed Vth1 and in the case where the vehicle speed VSPa is lower than the predetermined vehicle speed Vth1.

[0158] Fig. 11 illustrates a method of calculating the notification issuance distance in a case where the deceleration rates DEC1 and DEC2 are caused to be lower in a case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1 and the relative vehicle speed RSPb (= V22) of the straight traveling vehicle VB is used to calculate the notification issuance distances Dth1 and Dth2 than in a case where the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed Vth1 and the vehicle speed VSPb (= V21) of the straight traveling vehicle VB is used to calculate the notification issuance distances Dth1 and Dth2 as an example of a case of such setting.

[0159] In this manner, the first predetermined deceleration rate DEC1 to be used for calculating the information presentation distance Dth1 can be switched between a relatively high deceleration rate DEC11 and the deceleration rate DEC12 that is lower than the deceleration rate DEC11 in accordance with the vehicle speed VSPa of the right turning vehicle VA, and the second predetermined deceleration rate DEC2 to be used for calculating the alarm distance Dth2 can be switched between a relatively high deceleration rate DEC21 and the deceleration rate DEC22 that is lower than the deceleration rate DEC21 in accordance with the vehicle speed VSPa of the right turning vehicle VA.

[0160] It is possible to yet further suppress situations where the driver has anxiety through further optimization of the timing at which the notification issuance is performed by enabling the deceleration rates (that is, the first and second predetermined deceleration rates DEC1 and DEC2) to be used for calculating the notification issuance distances Dth1 and Dth2 to be switched in accordance with the vehicle speed VSPa of the right turning vehicle VA, causing the deceleration rates DEC1 and DEC2 to be lower in the case where the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed Vth1 than in a case where the vehicle speed VSPa is lower than the predetermined vehicle speed Vth1, and reflecting the sensation that the driver actually receives in response to approach of the counterpart vehicle to the notification issuance timing. Specifically, in a case where the driver of the straight traveling vehicle VB has a strong actual sensation in response to the approach of the right turning vehicle VA (more strongly perceives the approach of the right turning vehicle VA), it is possible to perform the notification issuance at an earlier timing by lowering the deceleration rates DEC1 and DEC2 and to secure a necessary time for the driver to take a measure, such as deceleration by a brake operation, in response to the notification issuance.

[0161] Furthermore, the deceleration rates DEC1 and DEC2 may be switched not only in accordance with the vehicle speed VSPa of the right turning vehicle VA but also in accordance with the vehicle speed VSPb or the relative vehicle speed RSPb of the straight traveling vehicle VB additionally or alternatively. For example, the first predetermined deceleration rate DEC1 is lowered as the vehicle speed VSPb or the relative vehicle speed RSPb increases in the calculation of the information presentation distance Dth1, and the second predetermined deceleration rate DEC2 is lowered as the vehicle speed VSPb or the relative vehicle speed RSPb increases in the calculation of the alarm distance Dth2.

[0162] 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.

[0163] 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.

[0164] 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, or 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 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, vehicles other than the right turning vehicle VA that are approaching the intersection CS and possible to enter the intersection CS are referred to as "intersection-entering vehicles." The intersection-entering vehicles may include not only the straight traveling vehicle VB but also crossing vehicles.

[0165] In the road layout shown in Figure 12, in addition to the right turning vehicle VA and the straight traveling vehicle VB, there may also be a crossing vehicle not shown in the figure as a vehicle heading toward the intersection CS. In a situation where there is no traffic signal installed at the intersection CS to control the movement of the crossing vehicle, there is a risk that the timing of the crossing vehicle entering the intersection CS may coincide with that of the right turning vehicle VA and the straight traveling vehicle VB, potentially leading to contact or collisions between these vehicles.

[0166] In such a situation, the notification system 1 monitors the relative positional relationship between the right turning vehicle VA and the crossing vehicle in addition to or instead of the control related to the notification between the right turning vehicle VA and the straight traveling vehicle VB after the right turn intention of the right turning vehicle VA is detected. Then, 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 VC 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 that conducted between the right turning vehicle VA and the straight traveling vehicle VB.

[0167] 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

[0168] 1 Vehicle notification system; 101a, 101b Controller; 111a, 111b Position sensor; 112a, 112b Vehicle speed sensor; 113a, 113b Right turn signal switch; 121a, 121b Transmitter; 122a, 122b Receiver; 131a, 131b HMI device; VA Right turning vehicle; VB Straight traveling vehicle.

Claims

1. A vehicle notification system (1) that performs notification issuance for traffic participants including a first vehicle (VA) that is present in a lane (L11) leading to an intersection (CS) and turns right or left at the intersection (CS) and a second vehicle (VB) that travels in a straight direction toward the intersection (CS) in a lane (L22) opposite to the lane (L11) where the first vehicle (VA) is present, the vehicle notification system (1) comprising: a notification issuance timing setting unit (B116a, B117a, B116b, B117b) that sets a notification issuance timing in accordance with a position of the first vehicle (VA) relative to the intersection (CS); and a notification issuing unit (B118a, B119a, B118b, B119b) that performs notification issuance in a predetermined mode for the traffic participants under a condition that a notification issuance condition defined in relation to a position of the second vehicle (VB) is met at the notification issuance timing set by the notification issuance timing setting unit (B116a, B117a, B116b, B117b), wherein the notification issuing unit (B118a, B119a, B118b, B119b) calculates a notification issuance distance on the basis of a preset deceleration rate as a distance required for deceleration of the second vehicle (VB), and performs notification issuance in the predetermined mode in a case where the second vehicle (VB) is located at the notification issuance distance from the intersection (CS) or is located at a position closer to the intersection (CS) than the notification issuance distance at the notification issuance timing.

2. The vehicle notification system (1) according to claim 1, further comprising: a relative vehicle speed detection unit (B115a, B115b, B112a, B112b) that detects a vehicle speed of the second vehicle (VB) relative to the first vehicle (VA), wherein the notification issuing unit (B118a, B119a, B118b, B119b) calculates the notification issuance distance on the basis of the deceleration rate and the relative vehicle speed of the second vehicle (VB).

3. The vehicle notification system (1) according to claim 2, further comprising: a first vehicle speed detection unit (112a, B115b) that detects a vehicle speed of the first vehicle (VA); and a second vehicle speed detection unit (B115a, 112b) that detects a vehicle speed of the second vehicle (VB), wherein the notification issuing unit (B118a, B119a, B118b, B119b) calculates the notification issuance distance on the basis of the deceleration rate and the relative vehicle speed of the second vehicle (VB) when the vehicle speed of the first vehicle (VA) detected by the first vehicle speed detection unit (112a, B115b) is higher than a predetermined vehicle speed, or calculates the notification issuance distance on the basis of the deceleration rate and the vehicle speed of the second vehicle (VB) detected by the second vehicle speed detection unit (B115a, 112b) when the vehicle speed of the first vehicle (VA) is lower than the predetermined vehicle speed.

4. The vehicle notification system (1) according to any one of claim 1 to claim 3, wherein the notification issuing unit (B118a, B119a, B118b, B119b) switches the deceleration rate in accordance with a vehicle speed of the first vehicle (VA) to calculate the notification issuance distance.

5. The vehicle notification system (1) according to any one of claim 1 to claim 3, wherein the notification issuing unit (B118a, B119a, B118b, B119b) switches the deceleration rate in accordance with a vehicle speed of the second vehicle (VB) or a relative vehicle speed of the second vehicle (VB) to calculate the notification issuance distance.

6. The vehicle notification system (1) according to claim 3, wherein the notification issuing unit (B118a, B119a, B118b, B119b) switches the deceleration rate between a case where the vehicle speed of the first vehicle (VA) is higher than the predetermined vehicle speed and a case where the vehicle speed of the first vehicle (VA) is lower than the predetermined vehicle speed to calculate the notification issuance distance.

7. The vehicle notification system (1) according to claim 6, wherein the notification issuing unit (B118a, B119a, B118b, B119b) causes the deceleration rate to be lower in a case where the vehicle speed of the first vehicle (VA) is higher than the predetermined vehicle speed than in a case where the vehicle speed of the first vehicle (VA) is lower than the predetermined vehicle speed.

8. The vehicle notification system (1) according to any one of claim 1 to claim 7, wherein the notification issuance timing setting unit (B116a, B117a, B116b, B117b) regards a point at which a path where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS) and a path where the second vehicle (VB) travels when the second vehicle (VB) passes the intersection (CS) intersect as a predicted collision point (CPP) and sets, as the notification issuance timings, a first notification issuance timing and a second notification issuance timing at which the first vehicle (VA) is located at a position closer to the predicted collision point (CPP) as compared with the first notification issuance timing, the notification issuing unit (B118a, B119a, B118b, B119b) performs notification issuance in the predetermined mode under a condition that the notification issuance condition is met at each of the first notification issuance timing and the second notification issuance timing set by the notification issuance timing setting unit (B116a, B117a, B116b, B117b), the notification issuing unit (B118a, B119a, B118b, B119b) includes, in the notification issuance condition at the first notification issuance timing, occurrence of a situation where the second vehicle (VB) is located at a first notification issuance distance from the intersection (CS) or is located at a position closer to the intersection (CS) than the first notification issuance distance, includes, in the notification issuance condition at the second notification issuance timing, occurrence of a situation where the second vehicle (VB) is located at a second notification issuance distance, which is shorter than the first notification issuance distance, from the intersection (CS) or is located at a position closer to the intersection (CS) than the second notification issuance distance, has, as the deceleration rates, a first predetermined deceleration rate and a second predetermined deceleration rate that is higher than the first predetermined deceleration rate, and calculates the first notification issuance distance on the basis of the first predetermined deceleration rate and calculates the second notification issuance distance on the basis of the second predetermined deceleration rate.

9. The vehicle notification system (1) according to any one of claim 1 to claim 8, wherein the notification issuing unit (B118a, B119a, B118b, B119b) calculates the notification issuance distance on the basis of a distance obtained by adding a predetermined brake reaction distance to a deceleration distance in accordance with the deceleration rate.

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