Vehicle notification system

Abstract

This vehicle notification system provides clear and easy-to-understand notifications for drivers regarding objects that require attention without interfering with their driving, thereby contributing to further improvements in traffic safety. [Solution] The vehicle notification system 1 includes a pedestrian detection unit B121a that detects a person to be monitored who can move on the sidewalk in a predetermined area of ​​the intersection CS or its surroundings, a first notification unit B118a and a second notification unit B119a that issue a first mode notification to avoid a collision between a right-turning vehicle VA and a straight-going vehicle VB, and a third notification unit B122a that issues a second mode notification to the right-turning vehicle VA to avoid a collision between the right-turning vehicle VA and a person to be monitored detected by the pedestrian detection unit B121a. The first mode notification and the second mode notification are each issued by the right-turning vehicle VA using different voices.

Description

Technical Field

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[0001] The present invention relates to a notification system for vehicles.

Background Art

[0002] For the purpose of providing driving assistance in a situation where a vehicle makes a right turn at an intersection on a left-hand traffic road, there is a technique for grasping the running situation of other traffic participants including oncoming vehicles that go straight towards the intersection in the oncoming lane, and instructing the driver of a right-turn timing that can avoid a collision with the oncoming vehicle.

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

Prior Art Documents

[0009] Therefore, the present invention aims to provide a vehicle notification system that enables drivers to easily understand what they should pay attention to without interfering with their driving, thereby contributing to further improvements in traffic safety. [Means for solving the problem]

[0010] To solve the aforementioned problems, a vehicle notification system according to one embodiment of the present invention is a vehicle notification system that provides at least audible alerts to traffic participants, including a vehicle turning right in a driving lane leading to an intersection and a vehicle traveling straight in the opposite lane toward the intersection, the notification system comprising: a person detection means for detecting a person to be monitored who can move on a sidewalk in a predetermined area of ​​the intersection or its vicinity; a first notification means for issuing a first mode of notification to avoid a collision between the right-turning vehicle and the straight-traveling vehicle; and a second notification means for issuing a second mode of notification to the right-turning vehicle to avoid a collision between the right-turning vehicle and the person to be monitored detected by the person detection means, wherein the first mode notification and the second mode notification are each performed by different voices in the right-turning vehicle. [Effects of the Invention]

[0011] According to one embodiment of the present invention, a vehicle notification system is provided that enables the implementation of notifications that do not interfere with driving and make it easy for the driver to understand what they should pay attention to, thereby contributing to further improvement of traffic safety. [Brief explanation of the drawing]

[0012] [Figure 1] Schematic diagram showing the overall configuration of a vehicle notification system according to an embodiment of the present embodiment. [Figure 2] Schematic diagram showing the internal configuration of a controller provided in a right-turning vehicle. [Figure 3] Schematic diagram showing the internal configuration of a controller provided in a straight-ahead vehicle. [Figure 4] Flowchart showing the overall flow of notification control. [Figure 5] Flowchart showing the content of early notification processing. [Figure 6] Flowchart showing the content of early notification processing (information presentation processing). [Figure 7] Flowchart showing the content of early notification processing (warning processing). [Figure 8] Flowchart showing the content of normal notification processing. [Figure 9] Flowchart showing the content of normal notification processing (information presentation processing). [Figure 10] Flowchart showing the content of normal notification processing (warning processing). [Figure 11] Explanatory diagram showing a method for calculating the information presentation distance and the warning distance. [Figure 12] Schematic diagram schematically showing an example of a traffic situation assumed as a notification target. [Figure 13] Schematic diagram showing the relationship between a right-turning vehicle and a straight-ahead vehicle at the notification timing of information presentation. [Figure 14] Schematic diagram showing the relationship between a right-turning vehicle and a straight-ahead vehicle at the notification timing of a warning. [Figure 15] Schematic diagram showing the setting situation when the intersection area is enlarged. [Figure 16] Schematic diagram showing the setting situation when the collision prediction area is reduced. [Figure 17] Schematic diagram showing the detection of a monitored person after the entry of a right-turning vehicle and the implementation timing of notification based on this to the intersection area. [Figure 18]Schematic diagram showing the detection of a monitored person before a right-turning vehicle reaches the intersection area and the timing of transmitting a report based on this detection. [Figure 19] Flowchart showing the overall flow of notification control according to another embodiment of the present invention. [Figure 20] Schematic diagram showing a situation where a straight-going vehicle passes through an intersection before a right-turning vehicle enters the intersection. [Figure 21] Schematic diagram showing a situation where a right-turning vehicle passes through an intersection before reaching the reporting position of a straight-going vehicle. [Figure 22] Schematic diagram showing an example of reporting in the first mode by display in notification control implemented in a right-turning vehicle. [Figure 23] Schematic diagram showing an example of reporting in the second mode by display in notification control implemented in a right-turning vehicle. [Figure 24] Schematic diagram showing an example of reporting in the first mode by display in notification control implemented in a straight-going vehicle. [Figure 25] Schematic diagram showing an example of reporting in the fourth mode by display in notification control implemented in a right-turning vehicle.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the plurality of drawings, the same or corresponding components are denoted by the same reference numerals.

[0014] (Overall Configuration of Vehicle Notification System) FIG. 1 is a schematic diagram showing the configuration of a vehicle notification system (hereinafter, may be simply referred to as "notification system") 1 according to an embodiment of the present invention.

[0015] In this embodiment, we assume a traffic situation in which a vehicle VA traveling on a left-hand road towards an intersection (hereinafter referred to as a "right-turning vehicle") and another vehicle VB traveling in the opposite lane (hereinafter referred to as the "opposing lane") towards the intersection are present. The notification system 1 is applicable not only to left-hand roads but also to right-hand roads. In the case of right-hand roads, the system targets a traffic situation in which a left-turning vehicle traveling towards an intersection and a straight-ahead vehicle traveling in the opposing lane towards the intersection are present. In other words, the notification system 1 is applicable to a traffic situation in which a right-turning or left-turning vehicle in the driving lane (hereinafter referred to as a "right-turning vehicle" or "non-straight-ahead vehicle") and a straight-ahead vehicle in the opposing lane coexist. In the case of left-hand roads, a right-turning vehicle is a vehicle that turns right at the intersection and must not obstruct the passage of a straight-ahead vehicle traveling in the opposing lane through the intersection.

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

[0017] In this embodiment, these various elements, including the controller 101, are provided in both the right-turning vehicle VA and the straight-going vehicle VB. The controller 101a in the right-turning vehicle VA and the controller 101b in the straight-going vehicle VB cooperate with each other to form a single virtual controller that constitutes the notification system 1. Naturally, the notification system 1 can be configured as an in-vehicle system for the right-turning vehicle VA using the controller 101a and its associated equipment, and it can also be configured as an in-vehicle system for the straight-going vehicle VB using the controller 101b and its associated equipment.

[0018] In the following description, vehicle-to-vehicle communication is performed between a right-turning vehicle VA and a straight-going vehicle VB, enabling the sharing of vehicle information related to the right-turning vehicle VA and the straight-going vehicle VB, and enabling the sharing of vehicle information related to the straight-going vehicle VB between both vehicles VA and VB. In this embodiment, the vehicle information to be communicated or shared between the right-turning vehicle VA and the straight-going vehicle VB includes the current position Pa, Pb, vehicle speed VSPa, VSPb, right turn signal operation status (i.e., output of the right turn signal switch), and lane ID of each vehicle VA and VB. Furthermore, this vehicle information may also include the type of each vehicle VA and VB. Communication between the right-turning vehicle VA and the straight-going vehicle VB is not limited to being performed directly by vehicle-to-vehicle communication, but can also be performed indirectly via roadside devices installed on the side of the road, servers located in remote locations, communication devices installed in vehicles other than the right-turning vehicle VA and the straight-going vehicle VB. Hereinafter, vehicle information relating to a right-turning vehicle VA will be referred to as right-turning vehicle information, and vehicle information relating to a straight-ahead vehicle VB will be referred to as straight-ahead vehicle information. In this embodiment, among the vehicle information that is communicated or shared between a right-turning vehicle VA and a straight-ahead vehicle VB, the type of each vehicle VA and VB refers to whether the right-turning vehicle VA and the straight-ahead vehicle VB are two-wheeled or four-wheeled vehicles, respectively.

[0019] In this embodiment, the right-turning vehicle VA and the straight-going vehicle VB constitute the notification system 1 with similar basic configurations. The right-turning vehicle VA is equipped with a controller 101a, as well as vehicle sensors 111a, 112a, 113a, communication devices 121a, 122a, and an HMI device 131a. On the other hand, the straight-going vehicle VB is equipped with a controller 101b, as well as vehicle sensors 111b, 112b, 113b, communication devices 121b, 122b, and an HMI device 131b.

[0020] Controllers 101a and 101b constitute the calculation unit of the notification system 1, and generate and output command signals according to the results of the calculations. Controllers 101a and 101b consist of a central processing unit (CPU), storage devices such as ROM and RAM, and a microcomputer equipped with input / output interfaces.

[0021] Vehicle sensors 111a to 113b and 111b to 113b constitute the detection unit of the notification system 1. The right-turning vehicle VA is equipped with a position sensor 111a, a vehicle speed sensor 112a, and a right turn signal switch 113a as associated vehicle sensors, while the straight-going vehicle VB is equipped with a position sensor 111b, a vehicle speed sensor 112b, and a right turn signal switch 113b as associated vehicle sensors.

[0022] Position sensor 111a detects the current position Pa of the right-turning vehicle VA, and position sensor 111b detects the current position Pb of the straight-going vehicle VB. Both position sensors 111a and 111b can be configured using receivers of a Global Navigation Satellite System (GNSS), and detect the current positions of the target vehicles VA and VB using latitude and longitude coordinates Pa (Pai, ​​Paj) and Pb (Pbi, Pbj).

[0023] Vehicle speed sensor 112a detects the driving speed (hereinafter referred to as "vehicle speed") VSPa of the right-turning vehicle VA, and vehicle speed sensor 112b detects the vehicle speed VSPb of the straight-going vehicle VB. Vehicle speed sensors 112a and 112b can detect the wheel speed (for example, the rotational speed of the driven wheels) of the target vehicles VA and VB, and can be calculated by converting this into a distance traveled per unit time using the tire radius, etc.

[0024] The right turn signal switch 113a outputs an ON signal when the right turn signal (hereinafter referred to as "right turn signal") of a right-turning vehicle VA is activated, and the right turn signal switch 113b outputs an ON signal when the right turn signal of a straight-going vehicle VB is activated. The operation of the right turn signal switches 113a and 113b indicates that the target vehicles VA and VB intend to turn right on the road or change lanes.

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

[0026] The HMI devices 131a and 131b constitute the output section (output means) of the notification system 1. The HMI device 131a receives a command signal from the controller 101a and provides notification regarding traffic conditions to the driver of the right-turning vehicle VA. The HMI device 131b receives a command signal from the controller 101b and provides notification regarding traffic conditions to the driver of the straight-going vehicle VB.

[0027] Notifications by HMI devices 131a and 131b are provided at least audibly. However, notifications by HMI devices 131a and 131b may also include visual information in addition to auditory information. In other words, the notification system 1 can issue notifications by voice (sound) via HMI devices 131a and 131b, and can also issue notifications by both voice (sound) and display. HMI devices 131a and 131b are placed in locations easily visible to the driver, such as the dashboard inside the vehicle.

[0028] Furthermore, the HMI devices 131a and 131b include, for example, speakers 141a and 141b as audio output means and displays 143a and 143b as display means. Speakers 141a and 141b transmit the content of the notification to the driver by voice (sound). This enables auditory notification. Displays 143a and 143b display the content of the notification to the driver, at least by illustration. The content of the notification displayed on displays 143a and 143b may include text. This enables visual notification. The HMI devices 131a and 131b also further include touch panels, switches, and keys, which are not shown in the illustration.

[0029] The right-turning vehicle VA is equipped with a transmitter 121a and a receiver 122a, while the straight-going vehicle VB is equipped with a transmitter 121b and a receiver 122b. The transmitter 121a and receiver 122a in the right-turning vehicle VA constitute the vehicle-to-vehicle communication device for the right-turning vehicle VA, and the transmitter 121b and receiver 122b in the straight-going vehicle VB constitute the vehicle-to-vehicle communication device for the straight-going vehicle VB. The right-turning vehicle VA and the straight-going vehicle VB can communicate wirelessly via their respective vehicle-to-vehicle communication devices.

[0030] As mentioned earlier, communication between a right-turning vehicle VA and a straight-ahead vehicle VB is not limited to direct communication between the two vehicles, but may also be indirect communication via a roadside device, a remote server, or another vehicle.

[0031] Furthermore, when the right-turning vehicle VA passes through an intersection, it monitors the intersection or a designated area around it, and if it detects a pedestrian or other monitored person in the designated area, it issues an alert, at least by voice, via the HMI device 131a to draw the attention of the right-turning vehicle (specifically, its driver) to the monitored person. The driver of the right-turning vehicle VA can, when a monitored person is present in the designated area, direct their attention to the monitored person and become aware of their presence through the activation of the HMI device 131a.

[0032] In this embodiment, the persons to be monitored refer to pedestrians or passengers of mobility scooters, or any other person legally permitted to move or travel on the sidewalk. The area in front of the center of the intersection (hereinafter referred to as the "center of the intersection") with respect to the direction of travel of the right-turning vehicle VA passing through the intersection, that is, the area including the pedestrian crossing on the road to which the vehicle is turning right (hereinafter sometimes referred to as the "pedestrian crossing to which the vehicle is turning right"), is defined as the "area surrounding the intersection," and this area surrounding the intersection is the subject of monitoring.

[0033] The controller 101a of the right-turning vehicle VA can communicate with the mobile communication device 201 possessed by the person being monitored. If the person being monitored is a pedestrian, the mobile communication device 201 is, for example, a mobile terminal such as a smartphone, and if the person being monitored is a passenger in a mobility scooter, the mobile communication device 201 is, for example, an in-vehicle communication device installed in the mobility scooter. Based on the signal transmitted from the mobile communication device 201, the controller 101a detects the location of the person being monitored and, if the person being monitored is located in the area surrounding the intersection, detects the person being monitored in the area surrounding the intersection.

[0034] Communication between the controller 101a and the mobile communication device 201 may be one-way communication from the mobile communication device 201 to the controller 101a, or it may be two-way communication. If the communication is two-way, it is possible to notify the monitored person of the presence of a right-turning vehicle VA that has detected the monitored person, and to draw the monitored person's attention to the right-turning vehicle VA. For example, the mobile communication device 201, which is a smartphone, can provide voice guidance informing the monitored person of the presence and approach of the right-turning vehicle VA.

[0035] Furthermore, communication between the controller 101a and the mobile communication device 201 may be direct or indirect. The controller 101a and the mobile communication device 201 can communicate unidirectionally or bidirectionally, for example, via a traffic signal SG installed next to a pedestrian crossing (specifically, a communication terminal provided on the traffic signal SG).

[0036] In addition to the mobile communication device 201, the detection of persons under surveillance can also be performed by surveillance cameras installed to monitor the area around the intersection. Specifically, images acquired by the surveillance cameras are analyzed, and if a person under surveillance is detected in the area around the intersection, a signal indicating that a person under surveillance has been detected is transmitted from the surveillance camera to the controller 101a.

[0037] Figure 12 is a schematic diagram illustrating an example of a traffic situation that is assumed to be the target of notification according to this embodiment.

[0038] In this embodiment, we assume a traffic situation where a right-turning vehicle VA and a straight-ahead vehicle VB are facing each other across an intersection CS. An intersection (a four-way intersection in this embodiment) CS exists on a two-lane road R, which includes right-turn lanes L11 and L21 and straight-ahead lanes L12 and L22. The right-turning vehicle VA is in one of the right-turn lane L11 and is approaching the intersection CS, while the straight-ahead vehicle VB is in the other straight-ahead lane L22 and is traveling in a straight direction toward the intersection CS, away from the intersection CS. Here, the right-turn lane L11 corresponds to the lane in which the right-turning vehicle VA is traveling, and the right-turn lane L21 and the straight-ahead lane L22 correspond to the opposing lanes to the right-turning vehicle VA. The opposing right-turn lane L21 and the straight-ahead lane L22 may be referred to as the "opposing right-turn lane" and the "opposing straight-ahead lane" below.

[0039] On road R, a pedestrian crossing PC1 is provided before intersection CS for the right-turn lane L11 and the straight-ahead lane L12, and a pedestrian crossing PC2 is provided before intersection CS for the opposing right-turn lane L21 and the opposing straight-ahead lane L22. Furthermore, a pedestrian crossing PC3 is provided on the road to which right-turning vehicles VA will turn right (i.e., the pedestrian crossing at the right-turn destination), and a pedestrian crossing PC4 is provided on the road on the opposite side of intersection CS from the road to which the right-turn destination is located. A stop line SL1 is provided at the front end of the right-turn lane L11 and the straight-ahead lane L12, which are close to intersection CS, and a stop line SL2 is provided at the front end of the opposing right-turn lane L21 and the opposing straight-ahead lane L22, which are close to intersection CS. Similarly, on other roads following intersection CS, stop lines SL3 and SL4 are provided before pedestrian crossings PC3 and PC4, respectively, when facing intersection CS.

[0040] In this embodiment, the area including the pedestrian crossing PC3 at the destination of the right turn and its surroundings is set as the "intersection surrounding area" AAC. Figure 12 schematically shows the intersection surrounding area AAC with a dashed frame. The intersection surrounding area AAC includes the area in front of and behind the pedestrian crossing PC3 in the longitudinal direction, and the area on both sides of the pedestrian crossing PC3 in the direction perpendicular to the longitudinal direction, as the "surroundings of the intersection". In other words, in this embodiment, the intersection surrounding area AAC is the area that extends from the pedestrian crossing PC3 in all four directions: front, back, left, and right. The intersection surrounding area AAC can be appropriately set as an area where there is a possibility of monitoring persons such as pedestrians being present, and can be set in an appropriate shape, such as an ellipse or oblong, in addition to the rectangle shown in Figure 12.

[0041] In addition to the right-turning vehicle VA and the straight-ahead vehicle VB, there is a vehicle VC waiting to turn right (hereinafter referred to as "waiting vehicle") in the opposing right-turn lane L21, just before the stop line SL2 in front of the straight-ahead vehicle VB. In the illustrated traffic situation, the waiting vehicle VC is a visual obstacle that obstructs part of the view from the right-turning vehicle VA and part of the view from the straight-ahead vehicle VB. From the perspective of the right-turning vehicle VA, the straight-ahead vehicle VB is in the blind spot of the waiting vehicle VC, making it difficult for the right-turning vehicle VA to see the straight-ahead vehicle VB. Conversely, from the perspective of the straight-ahead vehicle VB, the right-turning vehicle VA is in the blind spot of the waiting vehicle VC, making it difficult for the straight-ahead vehicle VB to see the right-turning vehicle VA.

[0042] In this situation, after the right-turning vehicle VA indicates its intention to turn right, the notification system 1 monitors the relative positional relationship between the right-turning vehicle VA and the straight-ahead vehicle VB. Then, at appropriate timings from when the right-turning vehicle VA approaches the intersection CS until it passes through the intersection CS, the system issues an alert according to the urgency of the situation regarding a potential collision between the right-turning vehicle VA and the straight-ahead vehicle VB. In this embodiment, the notification system 1 terminates its alerting when the right-turning vehicle VA has finished passing through the intersection CS.

[0043] In conjunction with this, if the notification system 1 detects a person under surveillance in the intersection surrounding area AAC, for example, a pedestrian crossing the crosswalk PC3, it will issue an alert to warn the person under surveillance to the right-turning vehicle VA. The following explanation will illustrate the case where a pedestrian is the person under surveillance.

[0044] (Internal configuration of the controller) Figure 2 is a schematic diagram showing the internal configuration of controller 101a installed in the right-turning vehicle VA, and Figure 3 is a schematic diagram showing the internal configuration of controller 101b installed in the straight-going vehicle VB. Referring to Figure 12 as appropriate, the internal configurations of controllers 101a and 101b will be explained in order with reference to Figures 2 and 3.

[0045] As shown in Figure 2, the controller 101a includes a self-vehicle position detection unit B111a, another vehicle position detection unit B112a, a road map storage unit B113a, a right-turn intention detection unit B114a, a driving state detection unit B115a, a first alarm timing setting unit B116a, a second alarm timing setting unit B117a, a first alarm unit B118a, a second alarm unit B119a, a judgment area setting unit B120a, a pedestrian detection unit B121a, and a third alarm unit B122a. The functions of each of these units B111a to B122a are implemented by a central processing unit in the controller 101a, which reads a computer program stored in a memory device and operates according to the instructions of that program.

[0046] Furthermore, the data held by each section B111a to B122a and the results of the processing performed by each section B111a to B122a can be mutually referenced among the sections B111a to B122a, regardless of the presence or absence of arrows in Figure 2 indicating the data flow inside the controller 101a. The data held by each section B111a to B122a includes vehicle information obtained from the straight-moving vehicle VB via the vehicle sensors 111a, 112a, 113a and receiver 122a output to the controller 101a. These assumptions in the controller 101a are the same in the controller 101b of the straight-moving vehicle VB.

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

[0048] The other vehicle position detection unit B112a detects the current position Pb of the other vehicle, which is a straight-moving vehicle VB. The detection of the current position Pb by the other vehicle position detection unit B112a is done by reading position information indicating the current position Pb from the vehicle information obtained from the straight-moving vehicle VB via the receiver 122a installed in the right-turning vehicle VA.

[0049] The road map storage unit B113a stores a road map. In this embodiment, the current positions Pa and Pb of the right-turning vehicle VA and the straight-going vehicle VB are the latitude and longitude coordinates indicating these positions Pa and Pb. The road map storage unit B113a extracts a map of the area or section including the intersection CS and its surroundings from the road map, and identifies the current positions Pa and Pb of the right-turning vehicle VA and the straight-going vehicle VB on that road map. The road map is assigned identifiers (hereinafter referred to as "link IDs") corresponding to each lane leading to the intersection CS, such as the right-turning lanes L11 and L21 and the straight-going lanes L12 and L22, and these are stored corresponding to each lane L11, L21, L12, and L22. By identifying the position on the road map, it is possible to determine the lane in which the target vehicle is located or traveling. Furthermore, the road map is set by identifying the coordinates on the road map of the location included in the intersection surrounding area AAC.

[0050] The right-turn intention detection unit B114a detects that the right-turning vehicle VA has the intention to turn right. The right-turn intention detection unit B114a can detect the intention to turn right based on the output signal from the right turn signal switch 113a on the right-turning vehicle VA. If the right-turn lane L11 is a right-turn-only lane, it can also detect that the right-turning vehicle VA is in the right-turn lane L11 by reading the link ID associated with the lane the vehicle is currently traveling in from the road map.

[0051] The driving state detection unit B115a detects the vehicle speed VSPb of the straight-moving vehicle VB. The detection of the vehicle speed VSPb by the driving state detection unit B115a is achieved by reading vehicle speed information indicating the vehicle speed VSPb from the vehicle information obtained from the straight-moving vehicle VB via the receiver 122a installed in the right-turning vehicle VA.

[0052] The first alarm timing setting unit B116a detects, based on the current position Pa of the right-turning vehicle VA on the road map, that after the right-turn intention detection unit B114a detects the intention to turn right, in other words, after the right-turning vehicle VA indicates its intention to turn right by entering the right-turn lane L11 or activating its right turn signal, that the right-turning vehicle VA is in a predetermined relative position with respect to the intersection CS, specifically, that it is at a predetermined distance from the center position of the intersection CS (i.e., the intersection center) CTR or closer to the intersection center CTR. The first alarm timing setting unit B116a then sets the timing at which it detects that the right-turning vehicle VA is in a predetermined relative position with respect to the intersection CS as the first alarm timing. The first alarm timing set by the first alarm timing setting unit B116a is the timing at which the right-turning vehicle VA issues an information presentation alarm. Here, the alarms issued at the first alarm timing and the second alarm timing described below, that is, the information presentation and alarm issuance by the controller 101a, correspond to the "first mode alarm" for the right-turning vehicle VA.

[0053] The second alarm timing setting unit B117a monitors the behavior of the right-turning vehicle VA after the first alarm timing has been set. The second alarm timing setting unit B117a defines the point where the path TRa that the right-turning vehicle VA travels when passing through intersection CS intersects with the path TRb that the straight-going vehicle VB travels when passing through intersection CS as the "collision prediction point" CPP, and based on the current position Pa of the right-turning vehicle VA on the road map, it detects whether the right-turning vehicle VA is traveling towards the collision prediction point CPP or has approached a predetermined distance from the collision prediction point CPP after the first alarm timing has been set. The second alarm timing setting unit B117a then sets the timing at which it detects either of these behaviors in the right-turning vehicle VA as the second alarm timing. The second alarm timing set by the second alarm timing setting unit B117a is the timing at which the alarm is issued for the right-turning vehicle VA.

[0054] Figure 13 is a schematic diagram showing the positional relationship between a right-turning vehicle VA and a straight-ahead vehicle VB at the moment when the right-turning vehicle VA crosses the stop line SL1 of the right-turn lane L11 and enters the intersection CS. In Figure 13, the illustration of the road R is simplified, and only the right-turn lane L11 and the straight-ahead lane L22 of the two-lane road R are shown (the same applies to Figures 14, 15, 16, 17, 18, 20, and 21 shown later).

[0055] In this embodiment, an intersection area ACS is set as a criterion for determining the relative positional relationship between a right-turning vehicle VA and an intersection CS. The intersection area ACS is set by the determination area setting unit B120a, which will be described later. The intersection area ACS is set to overlap the path TRa that the right-turning vehicle VA travels when passing through the intersection CS, and when the right-turning vehicle VA reaches or enters the intersection area ACS after indicating its intention to turn right, it is detected that the right-turning vehicle VA is in a predetermined relative position to the intersection CS. The intersection area ACS is set as a circular area with a predetermined radius φacs, concentric with the intersection center CTR. In Figures 13 to 18, 20 and 21, the intersection area ACS is shown by a dashed line, the travel path TRa of the right-turning vehicle VA is shown by a dashed line, and the collision prediction area ACP and the travel path TRb of the straight-going vehicle VB, which will be described next, are shown by a dashed line and a dashed line, respectively.

[0056] Figure 14 is a schematic diagram showing the positional relationship between the right-turning vehicle VA and the straight-ahead vehicle VB at the point when the right-turning vehicle VA enters the intersection CS, moves forward within the intersection CS, and approaches the intersection center CTR.

[0057] In this embodiment, a collision prediction area ACP is set as an area different from the intersection area ACS, centered on the collision prediction point CPP. The collision prediction area ACP is set by the determination area setting unit B120a, similar to the intersection area ACS. After entering the intersection area ACS, it is detected whether the right-turning vehicle VA is traveling within the intersection area ACS toward the collision prediction point CPP or is located within the collision prediction area ACP. The collision prediction area ACP is set as a circular area having a predetermined radius φacp and a smaller area than the intersection area ACS.

[0058] The intersection area ACS is not limited to a circle; it may be a shape that follows the area where the two intersecting roads overlap (for example, a rectangle with four corners cut off), or it may be the shape of the area enclosed by the stop lines SL1, SL2, SL3, and SL4 (Figure 12) installed on each of the intersecting roads. The same applies to the collision prediction area ACP; it can be set to a shape other than a circle, such as a rectangle (for example, a rectangle with two sides parallel to the road boundary line defining the opposing straight lane L22).

[0059] The first alarm unit B118a outputs a command signal to the HMI device 131a installed in its own vehicle (i.e., the right-turning vehicle VA) to issue an information presentation alarm, provided that a first predetermined alarm condition is met with respect to the position Pb of the other vehicle, which is the straight-moving vehicle VB, at the first alarm timing setting unit B116a.

[0060] The first predetermined alarm activation condition is that the straight-moving vehicle VB is at a relatively long first predetermined distance (hereinafter referred to as the "information presentation distance") Dth1 from the intersection CS, or is located closer to the intersection CS than this distance. In this embodiment, as the distance Db from the intersection CS to the straight-moving vehicle VB, as shown in Figures 13 and 14, the distance from the intersection of the travel path TRb of the straight-moving vehicle VB and the circle that defines the outer edge of the collision prediction area ACP (the circle shown by the dashed line in the same figure) to the straight-moving vehicle VB is adopted.

[0061] Upon receiving a command signal from the first alarm unit B118a, the HMI device 131a issues an alert, at least by voice, prompting the driver of the right-turning vehicle VA to recognize the presence of a straight-ahead vehicle VB traveling in the opposing straight-ahead lane L22 towards intersection CS. The alert issued by the first alarm unit B118a is an alert that provides information regarding a relatively low level of urgency concerning a collision between the right-turning vehicle VA and the straight-ahead vehicle VB.

[0062] The second alarm unit B119a outputs a command signal to the HMI device 131a to issue an alarm, provided that a second predetermined alarm condition, which is set in advance with respect to the position Pb of the straight-moving vehicle VB, is met at the second alarm timing setting unit B117a.

[0063] The second predetermined alarm activation condition is that the straight-ahead vehicle VB is at a second predetermined distance (hereinafter referred to as the "warning distance") Dth2 from the intersection CS that is shorter than the information presentation distance Dth1, or is at a position closer to the intersection CS than this distance.

[0064] The alarm is issued by at least an audible signal, and is a different audible signal from the informational signal. Upon receiving a command signal from the second alarm unit B119a, the HMI device 131a issues an alarm to the driver of the right-turning vehicle VA, at least by audibility, to encourage a greater awareness of the urgency regarding a collision between the right-turning vehicle VA and the straight-ahead vehicle VB. The alarm issued by the second alarm unit B119a is more prominent and appeals more to the driver's hearing, or to the driver's hearing and sight, compared to the alarm issued by the first alarm unit B118a.

[0065] The first alarm unit B118a and the second alarm unit B119a, in conjunction with outputting command signals to the HMI device 131a, can also notify the straight-moving vehicle VB via the transmitter 121a that alarms for each mode have been issued, prompting it to issue an appropriate alarm mode according to the urgency of the collision with its own vehicle (i.e., the right-turning vehicle VA).

[0066] Figure 11 is an explanatory diagram showing the calculation method for the information presentation distance Dth1 and the alarm distance Dth2.

[0067] The information presentation distance Dth1 and the warning distance Dth2 are calculated based on the vehicle speed VSPb of the straight-moving vehicle VB and the decelerations DEC1 and DEC2, which are set in advance according to the alarm mode. These are calculated as the distance that the straight-moving vehicle VB is expected to travel from the time of alarm until it comes to a stop, or in other words, the distance required for the straight-moving vehicle VB to come to a stop. Hereinafter, deceleration DEC1 may be referred to as the first predetermined deceleration DEC1, and deceleration DEC2 may be referred to as the second predetermined deceleration DEC2.

[0068] Specifically, the information presentation distance Dth1 is calculated by adding the expected distance traveled to the reaction time PRD1 and deceleration time PRD2, based on the vehicle speed VSPb (=V1) of the straight-moving vehicle VB at the first alarm timing set by the first alarm timing setting unit B116a. The reaction time PRD1 is the sum of the reaction time required for perception, judgment, and operation from the time of alarm until the driver actually performs the brake operation, and the delay time of the system and hydraulic equipment in response to the brake operation. In this embodiment, the reaction time PRD1 is set in advance as a constant time (=ΔT). The deceleration time PRD2 is the time required from when the brakes actually start to take effect until the vehicle comes to a stop, and can be calculated based on the vehicle speed VSPb and deceleration DEC1 (PRD2 = V1 / DEC1). The deceleration DEC1 is, for example, -0.1G. Thus, the information presentation distance Dth1 is calculated by the following equation (1). Dth1=V1×ΔT+V1×(V1 / DEC1) / 2 …(1)

[0069] Similarly, the warning distance Dth2 is calculated by adding the expected distance traveled to the coasting time PRD1 and the deceleration time PRD2, but a different deceleration DEC2 is used than the one used to calculate the information presentation distance Dth1. The deceleration DEC2 for calculating the warning distance is a higher deceleration than the deceleration DEC1 used for calculating the information presentation distance; in other words, it is a deceleration with a larger absolute value than deceleration DEC1 (|DEC1|<|DEC2|). For example, deceleration DEC2 is -0.2G. Specifically, it is calculated using the following equation (2). The vehicle speed V1 used to calculate the warning distance Dth2 is the vehicle speed VSPb of the straight-moving vehicle VB at the second alarm timing, but for simplicity, the vehicle speed VSPb at the first alarm timing may also be used. Dth2=V1×ΔT+V1×(V1 / DEC2) / 2…(2)

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

[0071] Both the intersection area (ACS) and the collision prediction area (ACP) can be set to have a variable size. In this embodiment, both the intersection area (ACS) and the collision prediction area (ACP) are set as circular areas, and their radii, i.e., the distances φacs and φacp from the intersection center (CTR) and collision prediction point (CPP) to the outer edges of each area (ACS) and ACP, are made changeable. The centers of each area (ACS) and ACP are maintained at the intersection center (CTR) and collision prediction point (CPP) before and after changing the size or radius.

[0072] The judgment area setting unit B120a sets the intersection area ACS and the collision prediction area ACP at the time when the right-turning vehicle VA indicates its intention to turn right but before it reaches the intersection CS. Then, after setting each area ACS and ACP, at the time when the right-turning vehicle VA reaches the intersection area ACS or after it has reached the intersection area ACS, the size of the collision prediction area ACP is changed according to the actual driving state of the right-turning vehicle VA in the intersection area ACS.

[0073] Specifically, the judgment area setting unit B120a sets the intersection area ACS to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and sets the collision prediction area ACP to a predetermined basic size, at the timing before the right-turning vehicle VA reaches the intersection CS. The setting of the intersection area ACS is done by expanding the intersection area ACS as the vehicle speed VSPa increases.

[0074] On the other hand, at the time when a right-turning vehicle VA reaches or has reached the intersection area ACS, the collision prediction area ACP is changed to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA in the intersection area ACS, while maintaining the intersection area ACS at a predetermined size, i.e., the basic size. Specifically, the lower the vehicle speed VSPa, the smaller the collision prediction area ACP is. In this embodiment, when the vehicle speed VSPa at or after reaching the intersection area ACS is higher than a predetermined vehicle speed Vth2 equivalent to a slow speed, the size of the collision prediction area ACP is maintained, and when the vehicle speed VSPa is less than or equal to the predetermined vehicle speed Vth2 and the right-turning vehicle VA is moving slowly or has stopped, the collision prediction area ACP is reduced. For example, the collision prediction area ACP is reduced to the smallest size set.

[0075] Figure 15 is a schematic diagram showing the settings when the intersection area ACS is expanded.

[0076] The judgment area setting unit B120a sets the intersection area ACS to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA before it reaches the intersection CS. In other words, the intersection area ACS is set when the right-turning vehicle VA is at a position away from the intersection CS, and the width or radius φacs of the intersection area ACS is set based on the vehicle speed VSPa of the right-turning vehicle VA and the pre-warning time Ppre corresponding to the vehicle speed VSPb of the straight-ahead vehicle VB.

[0077] The determination area setting unit B120a has a preset deceleration DEC1 and detects the vehicle speeds VSPa and VSPb of the right-turning vehicle VA and the straight-going vehicle VB, respectively, at the timing shown in Figure 15 before the right-turning vehicle VA reaches the intersection CS. In this embodiment, the deceleration DEC1 is the same as the predetermined deceleration DEC1 used to calculate the information presentation distance Dth1 described above.

[0078] Referring to Figure 11, the judgment area setting unit B120a calculates the pre-warning time Ppre, which is the time it takes for the vehicle speed VSPb of the straight-moving vehicle VB to decrease from the current vehicle speed (=V1) to 0 with a deceleration DEC1. The pre-warning time Ppre is calculated using the following equation (3). Alternatively, the calculation may be done using the following equation (4), taking into account the reaction time ΔT after the warning is issued. Ppre = VSPb / DEC1 …(3) Ppre = ΔT + VSPb / DEC1 …(4)

[0079] Then, the judgment area setting unit B120a multiplies the pre-announcement time Ppre by the vehicle speed VSPa of the right-turning vehicle VA, and sets the resulting distance as the radius φacs of the intersection area ACS. φacs = Ppre × VSPa …(5)

[0080] In this embodiment, the determination area setting unit B120a sets an expanded intersection area (hereinafter referred to as the "expanded intersection area") ACSe when the vehicle speed VSPa is higher than a predetermined vehicle speed, and sets a basic intersection area (hereinafter referred to as the "basic intersection area") ACSb with a predetermined expanded radius φacs according to the vehicle speed VSPa and VSPb when the vehicle speed is below a predetermined vehicle speed.

[0081] Figure 16 is a schematic diagram showing the settings when the collision prediction area (ACP) is reduced.

[0082] As mentioned earlier, in this embodiment, if the right-turning vehicle VA is moving slowly or has stopped before reaching the collision prediction area ACP after entering the intersection area ACS, the collision prediction area ACP is reduced to the smallest size possible according to the settings. The smallest size of the collision prediction area ACP has a diameter that approximately matches the lane width W of the straight-ahead vehicle VB, i.e., the straight-ahead lane L22 (φacp × 2 = W).

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

[0084] The pedestrian detection unit B121a detects pedestrians in the intersection surrounding area AAC, for example, pedestrians crossing the crosswalk PC3 ahead of a right-turning vehicle VA. In this embodiment, pedestrian detection is based on location information about the pedestrian that can be obtained from the pedestrian's mobile communication device (e.g., smartphone) 201. The pedestrian detection unit B121a identifies the pedestrian's location on a road map from the acquired location information and determines that the pedestrian's location is within the area on the map set as the intersection surrounding area AAC.

[0085] The third alarm unit B122a, when the pedestrian detection unit B121a detects a pedestrian in the intersection surrounding area AAC, outputs a command signal to the HMI device 131a installed in the vehicle (i.e., the right-turning vehicle VA) to issue an alert (hereinafter referred to as "pedestrian alert") to draw the vehicle's attention to the pedestrian. The alert based on the instruction from the third alarm unit B122a, i.e., the pedestrian alert, is usually preferably issued at a time other than the timing for issuing information and warning alerts to the right-turning vehicle VA. This can be achieved by selecting a time other than the timing for issuing information and warning alerts and detecting a pedestrian at that time, or by prioritizing the alert based on the former instruction when an instruction to issue an information or warning alert and an instruction to issue a pedestrian alert occur simultaneously. In this embodiment, in addition to outputting a command signal to the HMI device 131a, the third alarm unit B122a also outputs a signal to the controller 101b notifying it that a pedestrian alert has been issued. Based on this signal, controller 101b issues an alert to draw the attention of its own vehicle (i.e., the straight-ahead vehicle VB) to the right-turning vehicle VA. The pedestrian alert corresponds to the "second mode alert" for the right-turning vehicle VA, and the alert to draw the attention of the straight-ahead vehicle VB corresponds to the "third mode alert".

[0086] Figure 17 is a schematic diagram showing the positional relationship between the right-turning vehicle VA and the straight-ahead vehicle VB at the time a pedestrian warning is issued.

[0087] In this embodiment, it is preferable to issue a pedestrian warning when, after a right-turning vehicle VA enters the intersection area ACS, the straight-going vehicle VB is located at a position further than the information presentation distance Dth1 from the intersection CS. At the timing shown in Figure 17, the straight-going vehicle VB is neither at the information presentation distance Dth1 from the intersection CS nor closer to the intersection CS, so the controller 101a does not issue an information presentation warning.

[0088] In other words, in this embodiment, if, after the right-turning vehicle VA enters the intersection area ACS, the straight-ahead vehicle VB is located further than the information presentation distance Dth1 from the intersection CS, and therefore no information presentation is issued, it is preferable to issue a pedestrian warning alert on the condition that a pedestrian is detected in the surrounding intersection area AAC. Then, when the straight-ahead vehicle VB moves forward and approaches the information presentation distance Dth1 from the intersection CS, the pedestrian warning alert is stopped and an information presentation alert regarding a collision between the right-turning vehicle VA and the straight-ahead vehicle VB is issued. Furthermore, if the right-turning vehicle VA enters the collision prediction area ACP, and the straight-ahead vehicle VB also approaches the intersection CS to a position closer to the warning distance Dth2 or closer to the intersection CS, the alert mode is switched from information presentation to warning.

[0089] Upon receiving a command signal from the third alarm unit B122a, the HMI device 131a issues at least an audio alert as a pedestrian warning. In this embodiment, the transmission of an instruction from the third alarm unit B122a to the HMI device 131a constitutes the implementation of the pedestrian warning. When issuing the pedestrian warning, the audio differs depending on whether the right-turning vehicle VA is within the collision prediction area ACP or not. When issuing the pedestrian warning, the display may also differ depending on whether the right-turning vehicle VA is within the collision prediction area ACP or not. Specifically, if the right-turning vehicle VA is outside the collision prediction area ACP and has a relatively long time to reach the crosswalk PC3 at the destination of the right turn, the system issues an alert aimed at prompting the driver to recognize the presence of pedestrians in the intersection surrounding area AAC. On the other hand, if the right-turning vehicle VA is within the collision prediction area ACP and has approached the crosswalk PC3 at the destination of the right turn, the system issues an alert aimed at prompting the driver to take action to avoid contact with pedestrians.

[0090] The audio and display used when issuing a pedestrian warning, in other words, the mode of the pedestrian warning, may differ not only depending on whether the right-turning vehicle VA is within the collision prediction area ACP or not, but also depending on whether the right-turning vehicle VA is traveling outside the collision prediction area ACP towards the collision prediction point CPP at a vehicle speed VSPa higher than a predetermined vehicle speed or is within the collision prediction area ACP, and in other cases, that is, when the right-turning vehicle VA is outside the collision prediction area ACP and its vehicle speed VSPa is lower than a predetermined vehicle speed.

[0091] In this embodiment, the controller 101a provided in the right-turning vehicle VA and the controller 101b provided in the straight-going vehicle VB have basically the same configuration and have corresponding elements to each other.

[0092] As shown in Figure 3, the controller 101b includes a self-vehicle position detection unit B111b, another vehicle position detection unit B112b, a road map storage unit B113b, a right-turn intention detection unit B114b, a driving state detection unit B115b, a first alarm timing setting unit B116b, a second alarm timing setting unit B117b, a first alarm unit B118b, a second alarm unit B119b, and a judgment area setting unit B120b. The controller 101b may also include elements corresponding to a pedestrian detection unit B121a and a third alarm unit B122a, but these are omitted from the illustration because they are not required for a straight-moving vehicle VB. The internal configuration of the controller 101b will be described below, focusing on the differences from the controller 101a.

[0093] The vehicle position detection unit B111b detects the current position Pb of the straight-moving vehicle VB, which is the vehicle itself. The detection of the current position Pb is based on the output signal from the position sensor 111b installed in the straight-moving vehicle VB.

[0094] The other vehicle position detection unit B112b detects the current position Pa of the other vehicle, which is a right-turning vehicle VA. The current position Pa is detected by reading position information indicating the current position Pa from the vehicle information obtained from the right-turning vehicle VA via the receiver 122b installed in the straight-going vehicle VB.

[0095] The road map storage unit B113b, like the road map storage unit B113a, stores a road map that includes an intersection CS and assigns link IDs to each lane leading to the intersection CS, and identifies the current positions Pb and Pa of the straight-going vehicle VB and the right-turning vehicle VA on the road map, respectively. The road maps stored in the road map storage units B113b and B113a may have different accuracies, but in this embodiment, both are used with an accuracy that is compatible with satellite positioning by GNSS.

[0096] The right-turn intention detection unit B114b detects the right-turn intention of a right-turning vehicle VA. This right-turn intention is detected by identifying the link ID of the lane in which the right-turning vehicle VA is located from its current position Pa, or by reading information indicating the operation status of the right turn signal from vehicle information obtained from the right-turning vehicle VA via the receiver 122b. It is also possible to include the link IDs of the lanes in which each vehicle VA and VB are located in the vehicle information transmitted between the straight-going vehicle VB and the right-turning vehicle VA, and to detect the right-turn intention of the right-turning vehicle VA based on the link ID obtained through communication.

[0097] The driving state detection unit B115b detects the vehicle speed VSPa of the right-turning vehicle VA as the driving state of the right-turning vehicle VA. The detection of the vehicle speed VSPa is done by reading vehicle speed information indicating the vehicle speed VSPa from the vehicle information acquired from the right-turning vehicle VA via the receiver 122b.

[0098] The first alarm timing setting unit B116b detects, based on the current position Pa of the right-turning vehicle VA on the road map, that the right-turning vehicle VA has indicated its intention to turn right and is now at a predetermined relative position to the intersection CS. Specifically, as described above, it compares the current position Pa of the right-turning vehicle VA with the intersection area ACS and detects whether the right-turning vehicle VA has reached or entered the intersection area ACS. The first alarm timing setting unit B116b then sets the timing at which this is detected as the first alarm timing. The first alarm timing set by the first alarm timing setting unit B116b is the timing at which information presentation is issued to the straight-going vehicle VB. Here, the alarms issued at the first alarm timing and the second alarm timing described below, that is, the information presentation and warning alarms issued by the controller 101b, correspond to the "first mode alarm" for the straight-going vehicle VB.

[0099] The size and shape of the intersection area ACS may be the same or different for controller 101a and controller 101b. For example, the shape of the intersection area ACS can be made different between the two depending on the driver's choice or the driving conditions when passing through the intersection CS.

[0100] The second alarm timing setting unit B117b monitors the behavior of the right-turning vehicle VA after it enters the intersection CS, based on its current position Pa on the road map. After entering the intersection area ACS, it detects whether the right-turning vehicle VA is traveling within the intersection area ACS toward the collision prediction point CPP or is located within the collision prediction area ACP. The second alarm timing setting unit B117b then sets the timing at which it detects either of these behaviors in the right-turning vehicle VA as the second alarm timing. The second alarm timing set by the second alarm timing setting unit B117b is the timing at which an alarm is issued for the straight-going vehicle VB.

[0101] The size and shape of the collision prediction area ACP may differ between controller 101a and controller 101b, but in this embodiment, they are set to be the same. The collision prediction area ACP may be set to be the same size and shape for both controller 101a and controller 101b, or it may be set by notifying the other controller of the coordinate information of the collision prediction area ACP set by one of the controllers 101a or 101b via vehicle-to-vehicle communication.

[0102] The first alarm unit B118b outputs a command signal to the HMI device 131b installed in its own vehicle (i.e., the vehicle VB going straight) to issue an information presentation alert at the first alarm timing set by the first alarm timing setting unit B116b, provided that a first predetermined alarm condition relating to the position Pb of the vehicle VB going straight is met. As previously described, the first predetermined alarm condition is that the vehicle VB going straight is at an information presentation distance Dth1 from the intersection CS or is located closer to the intersection CS than this distance.

[0103] Upon receiving a command signal from the first alarm unit B118b, the HMI device 131b issues an alert, at least by voice, prompting the driver of the straight-going vehicle VB to be aware of the presence of a right-turning vehicle VA in the opposing right-turning lane L11. As described above, the alert issued by the first alarm unit B118b is an alert that provides information regarding a relatively low level of urgency regarding a collision between the straight-going vehicle VB and the right-turning vehicle VA.

[0104] The second alarm unit B119b outputs a command signal to the HMI device 131b to issue an alarm at a second alarm timing set by the second alarm timing setting unit B117b, provided that a second predetermined alarm condition relating to the position Pb of the straight-moving vehicle VB is met. The second predetermined alarm condition is that the straight-moving vehicle VB is at an alarm distance Dth2 from the intersection CS or is located closer to the intersection CS than this distance.

[0105] Upon receiving a command signal from the second alarm unit B119b, the HMI device 131b issues an alert to the driver of the straight-moving vehicle VB, at least by voice, to prompt them to recognize the increased urgency regarding a collision between the straight-moving vehicle VB and the right-turning vehicle VA. The alert issued by the second alarm unit B119b is similar to that described above, and the alert issued by the second alarm unit B119b is a more prominent warning that appeals to the driver's hearing, or a warning that appeals to the driver's hearing and sight.

[0106] The first alarm unit B118b and the second alarm unit B119b can also notify the right-turning vehicle VA via the transmitter 121b that an alarm for each mode has been issued, in conjunction with the output of a command signal to the HMI device 131b.

[0107] The judgment area setting unit B120b sets the intersection area ACS and the collision prediction area ACP. As described above, the judgment area setting unit B120b sets these areas ACS and ACP on the map of the range or section extracted by the road map storage unit B113b.

[0108] The intersection area ACS and collision prediction area ACP can also be set to have a variable size in controller 101b. Both the intersection area ACS and the collision prediction area ACP are set as circular areas, and their radii, i.e., the distances φacs and φacp from the intersection center CTR and collision prediction point CPP to the outer edges of each area ACS and ACP, can be changed.

[0109] The judgment area setting unit B120b detects the intention of the right-turning vehicle VA to turn right, and then sets the intersection area ACS and the collision prediction area ACP at the time before the right-turning vehicle VA reaches the intersection CS.

[0110] In this embodiment, the setting of the intersection area ACS and collision prediction area ACP by the determination area setting unit B120b is performed using the same procedure as the setting of each area ACS and ACP by the determination area setting unit B120a.

[0111] Specifically, the judgment area setting unit B120b sets the intersection area ACS to a width corresponding to the vehicle speed VSPa of the right-turning vehicle VA before it reaches the intersection CS, and sets the collision prediction area ACP to a basic predetermined width. The setting of the intersection area ACS is done by expanding the intersection area ACS as the vehicle speed VSPa increases. Furthermore, the judgment area setting unit B120b changes the collision prediction area ACP to a width corresponding to the vehicle speed VSPa of the right-turning vehicle VA in the intersection area ACS at the timing when the right-turning vehicle VA reaches or has reached the intersection area ACS, and shrinks the collision prediction area ACP as the vehicle speed VSPa decreases. In this embodiment, when the vehicle speed VSPa at or after reaching the intersection area ACS is less than or equal to a predetermined vehicle speed Vth2, and the right-turning vehicle VA is moving slowly or has stopped within the intersection area ACS, the collision prediction area ACP is reduced to the smallest width in the setting, specifically, to a diameter that approximately matches the lane width W of the straight lane L22.

[0112] Incidentally, notifications to drivers should ideally be clear to the driver, without interfering with their driving, and should clearly indicate what they should pay attention to. In other words, when a right-turning vehicle VA makes a right turn at intersection CS, it is desirable that the notification issued makes it easy for the driver of the right-turning vehicle VA to understand whether the object they should pay attention to is a straight-ahead vehicle VB or a person being monitored.

[0113] Therefore, the first mode alarm and the second mode alarm are performed in the right-turning vehicle VA via the HMI device 131a, which serves as the output means, using different voices.

[0114] Specifically, in the first mode of alerting a right-turning vehicle VA, depending on the situation, voice messages such as "There is a vehicle going straight," "There is a vehicle going straight nearby," or "There is a vehicle going straight very close by" are emitted from the speaker 141a of the HMI device 131a. In the second mode of alerting a right-turning vehicle VA, depending on the situation, voice messages such as "There is a pedestrian," "There is a pedestrian nearby," or "There is a pedestrian very close by" are emitted from the speaker 141a of the HMI device 131a. With voice alerts based on such relatively short sentences, the driver can understand the content of the alert in a short time without being interrupted while driving. Therefore, the driver of a right-turning vehicle VA can easily distinguish between the first mode alert and the second mode alert by the difference in voice, that is, the difference in the content of the voice alert. Therefore, even when the driver is intently watching the road ahead for driving purposes, they can accurately determine, without being interrupted, whether the object requiring their attention is a vehicle VB approaching straight ahead based on a first-mode alert, or a person being monitored based on a second-mode alert, based on different voice prompts.

[0115] Figure 22 is a schematic diagram showing an example of the activation of the first mode of notification by display in the notification control implemented for vehicles turning right.

[0116] Figure 23 is a schematic diagram showing an example of the activation of the second mode of notification by display in the notification control implemented for vehicles turning right.

[0117] Furthermore, as shown in Figures 22 and 23, it is preferable that the first mode alarm and the second mode alarm are issued by the right-turning vehicle VA via the HMI device 131a using different displays. This allows the driver of the right-turning vehicle VA to more accurately determine whether the object requiring attention is the straight-going vehicle VB based on the first mode alarm or the monitored person based on the second mode alarm, based on different displays in addition to different voice prompts.

[0118] Specifically, as shown in Figure 22, the first mode of notification is based on straight-ahead vehicle information obtained through communication between the right-turning vehicle VA and the straight-ahead vehicle VB. The right-turning vehicle VA displays information VBT indicating the type of straight-ahead vehicle VB, which is the vehicle opposite the right-turning vehicle VA, and information VBTD indicating the direction of travel (straight direction) of the straight-ahead vehicle VB, in the display area DAa of the display 143a of the HMI device 131a. In the example in Figure 22, information VBT indicating a four-wheeled vehicle as the type of straight-ahead vehicle VB is displayed as an illustration, and information VBTD indicating the direction of travel (straight direction) of the straight-ahead vehicle VB is displayed as an illustration and text. Information VBTD includes information VBTD1 displayed as an illustration and information VBTD2 displayed as text.

[0119] Furthermore, as shown in Figure 23, in the second mode, when a vehicle VA is turning right, information PE indicating the presence of a monitored person detected by the pedestrian detection unit B121a is displayed in the display area DAa of the HMI device 131a's display 143a. In the example in Figure 23, information PE is displayed using illustrations and text. Information PE includes information PE1 displayed using illustrations and information PE2 displayed using text.

[0120] Figure 24 is a schematic diagram showing an example of the first mode of notification activation by display in a notification control system implemented for vehicles traveling straight.

[0121] As shown in Figure 24, in the first mode, based on right-turn vehicle information obtained through communication between the right-turning vehicle VA and the straight-going vehicle VB, it is preferable that the straight-going vehicle VB displays information VAT indicating the type of right-turning vehicle VA that is the other vehicle for the straight-going vehicle VB, and information VATD indicating the direction of travel (right-turn direction) of the right-turning vehicle VA, in the display area DAb of the display 143b of the HMI device 131b. In the example in Figure 24, information VAT is displayed by illustration, and information VATD is displayed by illustration and text. Information VATD includes information VATD1 displayed by illustration and information VATD2 displayed by text. Furthermore, in the first mode of alarm activation based on the display of a right-turning vehicle VA, it is preferable that for informational alarm activation, information VBT indicating the type of straight-ahead vehicle VB and information VBTD indicating the direction of travel of the straight-ahead vehicle VB are displayed in a first color in the display area DAa of the display 143a, and for alarm activation, information VBT and information VBTD are displayed in a second color different from the first color in the display area DAa of the display 143a. Similarly, in the first mode of alarm activation based on the display of a straight-ahead vehicle VB, it is preferable that for informational alarm activation, information VAT and information VATD are displayed in a first color in the display area DAb of the display 143b, and for alarm activation, information VAT and information VATD are displayed in a second color in the display area DAb of the display 143b. The first color is, for example, yellow, and the second color is, for example, red.

[0122] Furthermore, it is preferable that the notification in the first mode be given with different voices depending on whether the right-turning vehicle VA is located within the extended intersection area ACSe or within an intersection area ACS other than the extended intersection area ACSe, i.e., within the basic intersection area ACSb.

[0123] Specifically, the driver of the right-turning vehicle VA can identify the first mode voice alert when the right-turning vehicle VA is within the expanded intersection area ACSe. This allows the driver to recognize the straight-ahead vehicle VB, which is the target of their attention, from the stage when the right-turning vehicle VA is within the expanded intersection area ACSe, where the distance to intersection CS is relatively long and there is ample margin. Therefore, the driver of the right-turning vehicle VA can take safer collision avoidance actions towards the straight-ahead vehicle VB once the right-turning vehicle VA reaches intersection CS. Similarly, the driver of the straight-ahead vehicle VB can identify the first mode voice alert when the right-turning vehicle VA is within the expanded intersection area ACSe. This allows the driver to recognize the right-turning vehicle VA, which is the target of their attention, from the stage when the right-turning vehicle VA is within the expanded intersection area ACSe, where the distance to intersection CS is relatively long and there is ample margin. Therefore, the driver of the straight-ahead vehicle VB can take safer collision avoidance actions towards the right-turning vehicle VA if, by any chance, the right-turning vehicle VA attempts to turn right at intersection CS before the straight-ahead vehicle VB has passed through intersection CS.

[0124] In addition, for the first mode, if a right-turning vehicle VA is located within the extended intersection area ACSe, a voice message such as "There is a vehicle going straight ahead." is emitted from the speaker 141a of the HMI device 131a, and if a right-turning vehicle VA is located within the basic intersection area ACSb, a voice message such as "There is a vehicle going straight ahead nearby." is emitted from the speaker 141b of the HMI device 131b.

[0125] Furthermore, it is preferable that the second mode alert is issued with different voices depending on whether the right-turning vehicle VA is located within the extended intersection area ACSe or within the intersection area ACS other than the extended intersection area ACSe, i.e., within the basic intersection area ACSb. This allows the driver of the right-turning vehicle VA to identify the person to be monitored, who is the target of their attention, from the stage when the right-turning vehicle VA is located within the extended intersection area ACSe, where the distance to the intersection CS is relatively long and there is more leeway. Therefore, when the right-turning vehicle VA reaches the intersection CS, the driver can take safer collision avoidance actions towards the person to be monitored.

[0126] In addition, the second mode of alerting is triggered by the speaker 141a of the HMI device 131a, for example, by emitting a voice message such as "There is a pedestrian" when a right-turning vehicle VA is located within the extended intersection area ACSe, and by emitting a voice message such as "There is a pedestrian nearby" when a right-turning vehicle VA is located within the basic intersection area ACSb.

[0127] Furthermore, it is preferable that the alarm for the third mode and the alarm for the first mode in the straight-moving vehicle VB are performed using the same voice.

[0128] Specifically, the driver of a straight-going vehicle VB typically does not need to pay attention to the monitored vehicle when passing through intersection CS. Therefore, by using the same voice for both the third-mode alert and the first-mode alert for the straight-going vehicle VB, the driver of the straight-going vehicle VB can focus their attention only on the right-turning vehicle VA. In other words, when the target of attention remains the right-turning vehicle VA, using the same voice for both the third-mode alert and the first-mode alert for the straight-going vehicle VB enables notification that does not interfere with the driver's driving.

[0129] In addition, when a straight-moving vehicle VB issues a warning in the first mode or the third mode, depending on the situation, for example, the speaker 141b of the HMI device 131b will emit a voice message such as "There is a vehicle turning right," "There is a vehicle turning right nearby," or "There is a vehicle turning right very close by."

[0130] Furthermore, it is preferable that the activation of the third mode alarm and the activation of the first mode alarm for the straight-moving vehicle VB be performed using the same display. In other words, it is preferable that the activation of the third mode alarm is also performed using the display shown in Figure 24. By doing so, even if a person who does not require attention is detected in the intersection CS or the designated area around the intersection AAC, the driver of the straight-moving vehicle VB can focus their attention only on the right-turning vehicle VA, which does require attention. In other words, when the person who should be paying attention remains the right-turning vehicle VA, by performing the activation of the third mode alarm and the activation of the first mode alarm for the straight-moving vehicle VB using the same voice and the same display, it is possible to reliably provide notifications to the driver of the straight-moving vehicle VB that do not interfere with driving.

[0131] Furthermore, if the pedestrian detection unit B121a detects a person under surveillance while the first mode of alarm is being issued as an information presentation alarm, the first alarm unit B118a and the third alarm unit B122a may, in the right-turning vehicle VA, issue a fourth mode of alarm via the HMI device 131a, which is different from the first mode of alarm and the second mode of alarm. In addition, if the pedestrian detection unit B121a detects a person under surveillance while the first mode of alarm is being issued as a warning alarm, the second alarm unit B119a and the third alarm unit B122a may, in the right-turning vehicle VA, issue a fourth mode of alarm via the HMI device 131a, which is different from the first mode of alarm and the second mode of alarm.

[0132] Specifically, when HMI device 131a receives a command signal from the first alarm unit B118a and issues an informational alarm, and then receives a command signal from the third alarm unit B122a, it will issue a fourth-mode alarm, for example, by emitting a voice message from speaker 141a saying, "There is a vehicle and a pedestrian going straight ahead," or "There is a vehicle and a pedestrian going straight ahead nearby." Also, when HMI device 131a receives a command signal from the second alarm unit B119a and issues an alarm, and then receives a command signal from the third alarm unit B122a, it will issue a fourth-mode alarm, for example, by emitting a voice message from speaker 141a saying, "There is a vehicle and a pedestrian going straight ahead very close by." The fourth-mode voice alarm consists of a combined voice notification content from the first-mode alarm and the second-mode alarm. By doing so, if the driver of the right-turning vehicle VA fails to notice the information alert, or ignores both the information alert and the warning alert and proceeds forward within the intersection CS, approaching the pedestrian crossing PC3, the driver of the right-turning vehicle VA will be alerted to the presence of pedestrians by a voice-based fourth-mode alert, prompting them to slow down or come to a complete stop before the pedestrian crossing PC3.

[0133] Figure 25 is a schematic diagram showing an example of a fourth mode notification by display in a notification control system implemented for vehicles turning right.

[0134] Furthermore, the activation of the fourth mode may also be performed by display.

[0135] Specifically, when the HMI device 131a receives a command signal from the first alarm unit B118a and issues an information alert, or receives a command signal from the second alarm unit B119a and issues an alarm, and then receives a command signal from the third alarm unit B122a, it displays a screen as shown in Figure 25 in the display area DAa of the display 143a as a fourth mode alert. In the example in Figure 25, the upper part of the display area DAa displays illustrations of information VBT indicating the type of straight-moving vehicle VB and information PE1 indicating the presence of a person being monitored. Furthermore, the middle part of the display area DAa displays illustrations of information VBTD1 indicating the direction of travel of the straight-moving vehicle VB. Finally, the lower part of the display area DAa displays text indicating the presence of a straight-moving vehicle VB and a pedestrian being monitored. As shown in Figures 22, 23, and 25, the fourth mode notification via display consists of notification content that combines the notification content of the first mode notification via display and the notification content of the second mode notification via display. In this way, if the driver of a right-turning vehicle VA does not notice the notification of information presentation, or ignores the notification of information presentation and the warning, and proceeds forward within the intersection CS and approaches the pedestrian crossing PC3, the driver of the right-turning vehicle VA will be made aware of the presence of pedestrians by the fourth mode notification based on the display in addition to the voice, and will be reliably encouraged to slow down or come to a complete stop before the pedestrian crossing PC3.

[0136] Furthermore, in the notification system 1, if, while at least an audible notification is being made, the road map storage units B113a and B113b detect that the right-turning vehicle VA has finished passing through intersection CS, it is preferable that the audible notification continues until a predetermined word, phrase, or sentence representing the notification content is read aloud at least once. This ensures that the reading of the notification content does not end prematurely, allowing the driver to understand the notification content more accurately.

[0137] Examples of designated sentences include, as mentioned above, "There is a vehicle going straight," "There is a vehicle turning right," and "There is a pedestrian." Designated phrases refer to further shortened expressions of these designated sentences, and designated words refer to designated phrases or a distinctive word from designated phrases. In addition, if a display notification is also being issued, the display notification may be terminated at the same time as the audio notification ends.

[0138] (Details of the notification control for vehicles turning right) Figures 4 to 10 are flowcharts showing the content of the notification control performed by the controller 101a installed in the right-turning vehicle VA. The flowchart in Figure 4 shows the overall flow of the notification control, the flowcharts in Figures 5 to 7 show the content of the early notification process, and the flowcharts in Figures 8 to 10 show the content of the normal notification process. Figures 6 and 9 show the content of the process performed by the right-turning vehicle VA regarding information presentation (information presentation process), and the flowcharts in Figures 7 and 10 show the content of the process performed by the right-turning vehicle VA regarding warnings (warning process). The information presentation process and warning process are performed as part of the notification control. When the controller 101a detects an intersection CS on the road in front of its own vehicle (i.e., the right-turning vehicle VA), it performs notification control at predetermined intervals.

[0139] In the flowchart shown in Figure 4, at S111, the controller 101a reads various control information used for notification control. The control information read at S111 includes the current position Pa, vehicle speed VSPa, and link ID of the right-turning vehicle VA, which is the controller's own vehicle, and the current position Pb, vehicle speed VSPb, and link ID of the straight-going vehicle VB, which is another vehicle. Information regarding the operation status of the right turn signals of the right-turning vehicle VA and the straight-going vehicle VB may also be included.

[0140] In S112, controller 101a determines whether it has detected a straight-ahead vehicle VB traveling in the opposite lane L22 toward intersection CS, relative to lane L11 where the right-turning vehicle VA is located. Detection of the straight-ahead vehicle VB is based on the link ID of the straight-ahead vehicle VB. If the straight-ahead vehicle VB is detected, the process proceeds to S113; otherwise, the current control is terminated.

[0141] In S113, the controller 101a determines whether or not it has detected the right-turning vehicle VA's intention to turn right. The detection of the intention to turn right is based on the operation status of the right turn signal of the right-turning vehicle VA. In addition to this, or instead, the determination can also be made based on the link ID of the right-turning vehicle VA. If the intention to turn right is detected, the process proceeds to S114; otherwise, the current control is terminated.

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

[0143] In S115, the controller 101a reads the vehicle speed VSPb of the straight-going vehicle VB, specifically the vehicle speed VSPb at the time it detects the intention of the right-turning vehicle VA to turn right.

[0144] In S116, the controller 101a sets the intersection area ACS and the collision prediction area ACP as the determination area. The setting of the intersection area ACS is based on the vehicle speeds VSPa and VSPb of the right-turning vehicle VA and the straight-going vehicle VB, respectively, at the time the intention to turn right is detected. In this embodiment, if the vehicle speed VSPa is higher than a predetermined vehicle speed, the expanded intersection area ACSe is set according to the vehicle speeds VSPa and VSPb, and if it is below the predetermined vehicle speed, the basic intersection area ACSb is set. In this embodiment, the collision prediction area ACP is set to the same width or radius φacp whether the vehicle speed VSPa is higher or lower than the predetermined vehicle speed, but it is also possible to make the width different in both cases and expand the collision prediction area ACP in conjunction with setting the expanded intersection area ACSe when the vehicle speed VSPa is higher than the predetermined vehicle speed.

[0145] In S117, controller 101a determines whether or not the extended intersection area ACSe has been set. If the extended intersection area ACSe has been set, the process proceeds to S118. If the basic intersection area ACSb has been set, the process is considered as not having set the extended intersection area ACSe and the process proceeds to S119.

[0146] In S118, controller 101a performs early alarm processing based on the extended intersection area ACSe and the collision prediction area ACP.

[0147] In S119, controller 101a performs normal alarm processing based on the basic intersection area ACSb and the collision prediction area ACP.

[0148] In the flowchart shown in Figure 5, at S211, the controller 101a reads various control information used for early alarm processing. The control information read at S211 includes the current position Pa and vehicle speed VSPa of the right-turning vehicle VA, and the current position Pb and vehicle speed VSPb of the straight-going vehicle VB.

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

[0150] In S213, controller 101a determines whether the right-turning vehicle VA has entered the expanded intersection area ACSe. If the right-turning vehicle VA is located at the outer edge of the expanded intersection area ACSe or closer to the intersection center CTR than this position, it is determined that the vehicle has entered the expanded intersection area ACSe, and the process proceeds to S214. If the vehicle VA is located further from the intersection center CTR than the outer edge of the expanded intersection area ACSe, it is determined that the vehicle has not entered the expanded intersection area ACSe, and the control process ends.

[0151] In S214, the controller 101a performs information presentation processing for early alarm activation according to the procedure shown in the flowchart in Figure 6.

[0152] In step S215, the controller 101a performs alarm processing for early notification according to the procedure shown in the flowchart in Figure 7.

[0153] In S216, the controller 101a determines whether or not an alarm has been issued in the information presentation processing or alarm processing for early alarm activation. If an alarm has been issued, the process proceeds to S219; otherwise, it proceeds to S217.

[0154] In S217, controller 101a determines whether or not it has detected a pedestrian in the intersection surrounding area AAC. If a pedestrian is detected, the process proceeds to S218; otherwise, it proceeds to S219.

[0155] At S218, controller 101a issues a pedestrian warning.

[0156] In S219, controller 101a determines whether the right-turning vehicle VA has passed through intersection CS. The determination of whether or not the vehicle has passed through intersection CS is made when the right-turning vehicle VA deviates from the expanded intersection area ACSe in the direction of travel after turning right. If the vehicle deviates from the expanded intersection area ACSe, it is considered that it has passed through intersection CS, and the current control is terminated. If the vehicle is still within the expanded intersection area ACSe, it is considered that it has not passed through intersection CS, and the process returns to S214, where information presentation processing and warning processing are repeatedly performed until the vehicle deviates from the expanded intersection area ACSe.

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

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

[0159] In S313, the controller 101a determines whether the right-turning vehicle VA is outside the collision prediction area ACP. If the right-turning vehicle VA is located between the outer edge of the intersection area ACS and the outer edge of the collision prediction area ACP, it is determined that it is outside the collision prediction area ACP, and the process proceeds to S314. If the vehicle VA is located at the outer edge of the collision prediction area ACP or closer to the collision prediction point CPP, it is determined that it is not outside the collision prediction area ACP, and the information presentation process ends.

[0160] In S314, the controller 101a calculates the distance Db from the intersection CS to the straight-moving vehicle VB, in other words, the distance remaining in front of the straight-moving vehicle VB before it reaches the intersection CS (hereinafter referred to as the "intersection arrival distance"). As shown in Figure 13, the intersection arrival distance Db is calculated as the distance from the outer edge of the collision prediction area ACP to the straight-moving vehicle VB.

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

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

[0163] In S317, the controller 101a determines whether the distance Db to the intersection for the straight-moving vehicle VB is less than or equal to the information presentation distance Dth1. In other words, the controller 101a determines whether the straight-moving vehicle VB is at or near the information presentation distance Dth1 from the intersection CS. If it is less than or equal to the information presentation distance Dth1, the process proceeds to S318. If it is longer than the information presentation distance Dth1, the information presentation process ends.

[0164] In S318, an information alert is issued.

[0165] In the flowchart shown in Figure 7, at S411, the controller 101a reads various control information used for early alarm processing. The control information read at S411 includes the current position Pa and vehicle speed VSPa of the right-turning vehicle VA, and the current position Pb and vehicle speed VSPb of the straight-going vehicle VB.

[0166] In S412, the controller 101a identifies the current positions Pa and Pb on the road map for the right-turning vehicle VA and the straight-going vehicle VB, respectively.

[0167] In S413, the controller 101a determines whether the right-turning vehicle VA is within the collision prediction area ACP. If the right-turning vehicle VA is located at the outer edge of the collision prediction area ACP or closer to the collision prediction point CPP, it is determined that the vehicle is within the collision prediction area ACP, and the process proceeds to S414. On the other hand, if the vehicle is located further from the collision prediction point CPP than the outer edge of the collision prediction area ACP, it is determined that the vehicle is not within the collision prediction area ACP, and the warning process ends.

[0168] In S414, controller 101a calculates the distance Db to the intersection for the straight-moving vehicle VB.

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

[0170] In S416, the controller 101a calculates the warning distance Dth2. The warning distance Dth2 is calculated based on the vehicle speed VSPb of the straight-moving vehicle VB and a second predetermined deceleration DEC2, specifically by the above equation (2).

[0171] In S417, the controller 101a determines whether the distance Db of the straight-ahead vehicle VB to the intersection is less than or equal to the warning distance Dth2, in other words, whether the straight-ahead vehicle VB is at a warning distance Dth2 from the intersection CS or is still close to the intersection CS. If it is less than or equal to the warning distance Dth2, the process proceeds to S418; if it is longer than the warning distance Dth2, the warning process is terminated.

[0172] In S418, controller 101a triggers an alarm.

[0173] The procedure shown in the flowchart of Figure 8 differs from the procedure shown in the flowchart of Figure 5 only in the processing performed by the controller 101a in S513. In S513, the controller 101a determines whether the right-turning vehicle VA has entered the basic intersection area ACSb. If the right-turning vehicle VA is located at the outer edge of the basic intersection area ACSb or closer to the intersection center CTR than this position, it is determined that the vehicle has entered the basic intersection area ACSb, and the process proceeds to S514. In S514, the controller 101a performs information presentation processing for normal alarm activation according to the procedure shown in the flowchart of Figure 9, and in the subsequent S515, it performs alarm processing for normal alarm activation according to the procedure shown in the flowchart of Figure 10. On the other hand, if the right-turning vehicle VA is located further from the intersection center CTR than the outer edge of the basic intersection area ACSb, it is determined that the vehicle has not entered the basic intersection area ACSb, and the current control is terminated. The processes performed by the controller 101a in S511, S512, S514 to S519 are the same as the processes performed by the controller 101a in S211, S212, S214 to S219 shown in the flowchart of Figure 5. In S516, the controller 101a determines whether or not it has issued an alert in the normal information presentation process or alarm process for issuing an alert. If an alert has been issued, it proceeds to S519. On the other hand, if an alert has not been issued, it proceeds to S517, where the controller 101a determines whether or not it has detected a pedestrian in the intersection surrounding area AAC. If a pedestrian has been detected, it proceeds to S518, where the controller 101a issues a pedestrian warning alert.

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

[0175] In S612, the controller 101a identifies the current positions Pa and Pb on the road map for the right-turning vehicle VA and the straight-going vehicle VB, respectively.

[0176] In S613, the controller 101a determines whether the right-turning vehicle VA is outside the collision prediction area ACP. If the right-turning vehicle VA is outside the collision prediction area ACP, the process proceeds to S614. If the vehicle is not outside the collision prediction area ACP, the information presentation process ends.

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

[0178] In S615, the controller 101a determines whether the vehicle speed VSPa of the right-turning vehicle VA is less than or equal to the first predetermined vehicle speed Vth1. If the vehicle speed VSPa is less than or equal to the first predetermined vehicle speed Vth1, the process proceeds to S616, as it is time to issue an information alert. If the vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1, the information alert process is terminated. The first predetermined vehicle speed Vth1 is set from the perspective of whether it is possible to secure sufficient time for effective information alerting. Such time can be secured at vehicle speeds VSPa less than or equal to the first predetermined vehicle speed Vth1, but not at vehicle speeds VSPa exceeding it. Therefore, the controller 101a determines that it is necessary to issue an alert when the right-turning vehicle VA reaches the collision prediction area ACP or when the straight-going vehicle VB approaches the collision prediction area ACP. The first predetermined vehicle speed Vth1 is, for example, 20 km / h.

[0179] Thus, in this embodiment, when a right-turning vehicle VA enters the intersection area ACS with a relatively low vehicle speed VSPa by temporarily stopping at the stop line SL1 before the intersection CS or by sufficiently slowing down before entering the intersection area ACS, the detection of such a situation is considered to be the timing for issuing an information alert, and the processing from S616 onwards is carried out to determine whether the alert condition has been met. The timing for issuing an information alert is not limited to this, and it is also possible to set it based on the fact that the right-turning vehicle VA has entered the intersection area ACS, or in other words, is inside the intersection area ACS, without imposing any restrictions based on driving conditions such as vehicle speed VSPa.

[0180] In S616, controller 101a calculates the distance Db that the straight-moving vehicle VB will reach at the intersection.

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

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

[0183] In S619, the controller 101a determines whether the distance Db to the intersection for the straight-moving vehicle VB is less than or equal to the information presentation distance Dth1. If it is less than or equal to the information presentation distance Dth1, the process proceeds to S620. If it is longer than the information presentation distance Dth1, the information presentation process ends.

[0184] At S620, controller 101a issues an alert to provide information.

[0185] In the flowchart shown in Figure 10, at S711, the controller 101a reads various control information used for normal alarm processing. The control information read at S711 includes the current position Pa and vehicle speed VSPa of the right-turning vehicle VA, and the current position Pb and vehicle speed VSPb of the straight-going vehicle VB.

[0186] In S712, the controller 101a identifies the current positions Pa and Pb on the road map for the right-turning vehicle VA and the straight-going vehicle VB, respectively.

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

[0188] In S714, the controller 101a determines whether the vehicle speed VSPa of the right-turning vehicle VA is higher than the second predetermined vehicle speed Vth2. If it is higher than the second predetermined vehicle speed Vth2, the process proceeds to S716; otherwise, the process proceeds to S715. The second predetermined vehicle speed Vth2 is set to the speed that would be used when the right-turning vehicle VA is traveling at a low speed, for example, when proceeding slowly. If the vehicle speed VSPa is less than or equal to the second predetermined vehicle speed Vth2, the controller 101a determines from the behavior of the right-turning vehicle VA that the driver of the right-turning vehicle VA is paying sufficient attention to the surrounding conditions and other traffic participants when passing through the intersection CS. The second predetermined vehicle speed Vth2 is, for example, 5 km / h.

[0189] In S715, the controller 101a reduces the collision prediction area ACP. In this embodiment, the collision prediction area ACP is reduced to the smallest possible width in the settings, and its diameter is set to approximately match the lane width W of the straight lane L22 on which the straight-moving vehicle VB is traveling.

[0190] In S716, controller 101a determines whether the right-turning vehicle VA is within the collision prediction area ACP. If it is within the collision prediction area ACP, proceed to S718; otherwise, proceed to S717.

[0191] In S717, the controller 101a determines whether the vehicle speed VSPa of the right-turning vehicle VA is higher than the first predetermined vehicle speed Vth1. If it is higher than the first predetermined vehicle speed Vth1, the process proceeds to S718. If it is less than or equal to the first predetermined vehicle speed Vth1, the warning process is terminated. If the right-turning vehicle VA is not within the collision prediction area ACP and the vehicle speed VSPa is less than or equal to the first predetermined vehicle speed Vth1, the information presentation process is performed to issue an information presentation alert (S615 in the flowchart shown in Figure 9).

[0192] Thus, from S714 to S717, the controller 101a detects that after a right-turning vehicle VA enters the intersection area ACS, reaches the collision prediction area ACP, and is either already inside the collision prediction area ACP or, even if outside the collision prediction area ACP, is traveling towards the collision prediction point CPP at a speed above a certain level and approaching the collision prediction area ACP. Based on the detection of such a situation, the controller 101a determines that it is time to issue a warning and proceeds with the processing from S718 onwards to determine whether the warning conditions have been met.

[0193] In S718, controller 101a calculates the distance Db to the intersection for the straight-moving vehicle VB.

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

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

[0196] In S721, the controller 101a determines whether the distance Db to the intersection for the straight-moving vehicle VB is less than or equal to the warning distance Dth2. If it is less than or equal to the warning distance Dth2, the process proceeds to S722. If it is longer than the warning distance Dth2, the warning process is terminated.

[0197] In S722, controller 101a triggers an alarm.

[0198] The information dissemination during early alarm activation and the information dissemination during normal alarm activation can take different forms, but in this embodiment, they take the same form (for example, the same display and sound). The same applies to alarm dissemination; the same form of dissemination may be used for early alarm activation and normal alarm activation, or different forms of dissemination may be used.

[0199] (Details of the notification control for vehicles traveling straight) Controller 101b performs notification control at predetermined intervals when it detects an intersection CS on the road ahead of its own vehicle (i.e., the straight-moving vehicle VB). The execution cycle of notification control for controller 101a and controller 101b may be the same or different. Furthermore, it is also possible to synchronize the execution of notification control between both controllers 101a and 101b.

[0200] The processes performed by controller 101a and controller 101b regarding notification control correspond to each other. Therefore, the notification control performed by controller 101b will be explained with reference to the flowcharts shown in Figures 4 to 10.

[0201] After the notification control is started, the controller 101b reads various control information used for the notification control (S111 as shown in the flowchart in Figure 4), detects another vehicle in the right-turn lane L11 of the opposing lane, i.e., the right-turning vehicle VA (S112), and then determines whether or not it has detected the right-turning vehicle VA's intention to turn right (S113). If the controller 101b detects the intention to turn right, it reads the vehicle speed VSPb of its own vehicle, the straight-going vehicle VB, and also reads the vehicle speed VSPa of the right-turning vehicle VA, and sets the determination area (intersection area ACS and collision prediction area ACP) based on the vehicle speed VSPa and VSPb (S116). As described above, if the vehicle speed VSPa is higher than a predetermined vehicle speed, the controller 101b sets an extended intersection area ACSe with a relatively large radius φacs, and if it is below the predetermined vehicle speed, it sets a basic intersection area ACSb with a smaller radius φacs. Then, if the extended intersection area ACSe is set, the controller 101b performs early alarm processing (S118), otherwise it performs normal alarm processing (S119).

[0202] In the early alarm processing, after the controller 101b reads various control information (S211 as shown in the flowchart in Figure 5), it identifies the current position Pa of the right-turning vehicle VA on the road map (S212) and determines whether the right-turning vehicle VA has entered the expanded intersection area ACSe (S213). If the controller 101b has entered the expanded intersection area ACSe, it continues processing and performs information presentation processing and alarm processing (S214, S215). If it has not entered, it terminates the current control. Here, if the controller 101b receives a signal from the controller 101a indicating that a pedestrian warning has been issued, it issues an alarm to the driver to draw attention to another vehicle (i.e., the right-turning vehicle VA). This alarm is intended to draw the driver's awareness that, for example, the right-turning vehicle VA may stop before the pedestrian crossing PC3 at the destination of the right turn, that is, ahead in the direction of travel of the vehicle. Information display processing and warning processing are performed repeatedly until the right-turning vehicle VA passes through the expanded intersection area ACSe (S219).

[0203] In the information presentation process for early notification, the controller 101b reads various control information (S311 as shown in the flowchart in Figure 6) and then identifies the current positions Pb and Pa on the road map of the straight-going vehicle VB and the right-turning vehicle VA, respectively (S312). The controller 101b determines whether the right-turning vehicle VA is outside the collision prediction area ACP (S313), and if it determines that it is outside the collision prediction area ACP, it calculates the intersection arrival distance Db of the straight-going vehicle VB (S314), and calculates the information presentation distance Dth1 according to the vehicle speed VSPb of the straight-going vehicle VB (S315, S316). If the intersection arrival distance Db is less than or equal to the information presentation distance Dth1 (S317), it issues an information presentation notification (S318).

[0204] In the early warning processing, the controller 101b reads various control information (S411 as shown in the flowchart in Figure 7) and identifies the current positions Pb and Pa on the road map of the straight-going vehicle VB and the right-turning vehicle VA, respectively (S412). The controller 101b determines whether the right-turning vehicle VA is within the collision prediction area ACP (S413), and if it determines that it is within the collision prediction area ACP, it calculates the intersection arrival distance Db of the straight-going vehicle VB (S414), and calculates the warning distance Dth2 according to the vehicle speed VSPb of the straight-going vehicle VB (S415, S416). If the intersection arrival distance Db is less than or equal to the warning distance Dth2 (S417), it issues a warning (S418).

[0205] In the normal alarm activation process, after the controller 101b reads various control information (S511 as shown in the flowchart in Figure 8), it identifies the current position Pa of the right-turning vehicle VA on the road map (S512) and determines whether the right-turning vehicle VA has entered the basic intersection area ACSb (S513). If it has entered the basic intersection area ACSb, the process continues to perform information presentation processing and alarm processing (S514, S515). If it has not entered, the current control is terminated. As described above, if the controller 101b receives a signal from the controller 101a indicating that a pedestrian warning alarm has been issued, it issues an alarm to the driver to warn them to pay attention to another vehicle (i.e., the right-turning vehicle VA). The information presentation processing and alarm processing are repeated until the right-turning vehicle VA passes through the basic intersection area ACSb (S519).

[0206] In the normal information presentation process for issuing an alert, the controller 101b reads various control information (S611 as shown in the flowchart in Figure 9), and then identifies the current positions Pb and Pa on the road map of the straight-going vehicle VB and the right-turning vehicle VA, respectively (S612). The controller 101b determines whether the right-turning vehicle VA is outside the collision prediction area ACP (S613), and if it determines that it is outside the collision prediction area ACP, it reads the vehicle speed VSPa of the right-turning vehicle VA (S614), and determines whether the vehicle speed VSPa is less than or equal to the first predetermined vehicle speed Vth1 (S615). The controller 101b calculates the distance Db the straight-moving vehicle VB will reach the intersection if the vehicle speed Vth1 is less than or equal to the first predetermined vehicle speed (S616), and calculates the information presentation distance Dth1 according to the vehicle speed VSPb of the straight-moving vehicle VB (S617, S618). If the distance Db to the intersection is less than or equal to the information presentation distance Dth1 (S619), the controller 101b issues an information presentation alert (S620).

[0207] In the normal alarm processing for triggering an alarm, the controller 101b reads various control information (S711 as shown in the flowchart of Figure 10), and then identifies the current positions Pb and Pa on the road map of the straight-going vehicle VB and the right-turning vehicle VA, respectively (S712). The controller 101b reads the vehicle speed VSPa of the right-turning vehicle VA (S713) and determines whether the vehicle speed VSPa is higher than a second predetermined vehicle speed Vth2 (S714). If the vehicle speed VSPa is higher than the second predetermined vehicle speed Vth2, the controller 101b maintains the collision prediction area ACP at the already set width, while if it is less than or equal to the second predetermined vehicle speed Vth2, it reduces the collision prediction area ACP (S715). If the right-turning vehicle VA is within the collision prediction area ACP (S716), or if it is outside the collision prediction area ACP but its vehicle speed VSPa is higher than the first predetermined vehicle speed Vth1 (S717), the distance Db to the intersection for the straight-going vehicle VB is calculated (S718), and the warning distance Dth2 corresponding to the vehicle speed VSPb of the straight-going vehicle VB is calculated (S719, S720). If the distance Db to the intersection is less than or equal to the warning distance Dth2 (S721), a warning is issued (S722).

[0208] (Explanation of action and effects) The vehicle notification system 1 according to this embodiment has the above configuration. The effects obtained by this embodiment will be described below.

[0209] Firstly, in a situation where a right-turning vehicle VA and a straight-ahead vehicle VB are facing each other across an intersection CS, after detecting that the right-turning vehicle VA intends to turn right, the system sets an alert timing according to the relative position of the right-turning vehicle VA and the intersection CS, i.e., the timing for information presentation and warning presentation. At these alert timings, provided that the specified alert conditions regarding the position of the straight-ahead vehicle VB are met, the system presents information or issues a warning to all traffic participants, including the right-turning vehicle VA and the straight-ahead vehicle VB. This makes it possible to provide an alert in the appropriate mode at the appropriate timing according to the urgency of the situation in a situation where there is a risk of collision between the right-turning vehicle VA and the straight-ahead vehicle VB.

[0210] Then, the system monitors the intersection CS or a predetermined area around it, in this embodiment, the intersection surrounding area AAC. When a pedestrian, who is a target of monitoring, is detected in the intersection surrounding area AAC, an alert is issued to draw the attention of the right-turning vehicle VA to the pedestrian, i.e., a pedestrian alert is issued. This makes it possible to draw the attention of the right-turning vehicle VA to potential targets of monitoring other than the straight-ahead vehicle VB, such as pedestrians crossing the pedestrian crossing PC3 around the intersection CS, in situations where attention tends to be focused on the oncoming lane L22, and to avoid contact between the right-turning vehicle VA and the target of monitoring.

[0211] Here, by defining the area for detecting the person being monitored as the pedestrian crossing ahead of the intersection center CTR with respect to the direction of travel of the right-turning vehicle VA, that is, the area around the intersection AAC including the pedestrian crossing PC3 at the destination of the right turn, it becomes possible to avoid contact with the person being monitored at the pedestrian crossing PC3 at the destination of the right turn, which is highly likely to occur when the right-turning vehicle VA passes through the intersection CS.

[0212] Secondly, by setting an intersection area ACS and setting an alert timing after a right-turning vehicle VA enters the intersection area ACS, information is presented or a warning is issued on the condition that a straight-ahead vehicle VB is at an alerting distance Dth1 or Dth2 from the intersection CS, or is closer to the intersection CS. On the other hand, if the straight-ahead vehicle VB is farther from the intersection CS than the alerting distance Dth1 or Dth2 and the alerting conditions are not met, a pedestrian warning is issued upon detection of a pedestrian in the surrounding intersection area AAC. This makes it possible to issue a pedestrian warning to a right-turning vehicle VA within the intersection area ACS when the straight-ahead vehicle VB is far from the intersection CS, and to present information or issue a warning when the straight-ahead vehicle VB approaches the intersection CS.

[0213] In this way, for right-turning vehicles VA located within the intersection area ACS, the alarm mode can be switched according to the position of straight-ahead vehicles VB, enabling alarms to be issued in the appropriate mode according to the situation. Specifically, when straight-ahead vehicles VB are far from the intersection CS and the urgency of a collision with right-turning vehicles VA is low, a pedestrian warning alarm is issued to alert the right-turning vehicles VA to pedestrians. On the other hand, when straight-ahead vehicles VB approach the intersection CS and the urgency increases, the alarm mode can be switched to information display or warning to encourage the right-turning vehicles VA to recognize that straight-ahead vehicles VB are approaching.

[0214] Thirdly, by setting a collision prediction area ACP and issuing pedestrian warnings with different voices or different voices and displays depending on whether the right-turning vehicle VA is traveling outside the collision prediction area ACP towards the collision prediction point CPP at a vehicle speed VSPa higher than a predetermined vehicle speed Vth1, or is inside the collision prediction area ACP, or otherwise, it becomes possible to issue pedestrian warnings in a mode that corresponds to the urgency of the situation regarding contact with monitored persons, such as pedestrians crossing the crosswalk PC3 at the destination of the right turn.

[0215] Fourthly, after detecting the intention to turn right, if the vehicle speed VSPa of the right-turning vehicle VA traveling towards intersection CS is higher than a predetermined speed, the extended intersection area ACSe is set. If a pedestrian is detected in the surrounding intersection area AAC after the right-turning vehicle VA enters the extended intersection area ACSe, a pedestrian warning is issued. This makes it possible to issue a pedestrian warning earlier compared to when the vehicle speed VSPa of the right-turning vehicle VA is lower than a predetermined speed. As a result, it is possible to make the right-turning vehicle VA, which is traveling towards intersection CS at a relatively high speed, recognize the presence of a pedestrian earlier and encourage it to slow down sufficiently before reaching the crosswalk PC3 at the destination of the right turn.

[0216] Furthermore, by encouraging right-turning vehicles (VA) to decelerate at an earlier stage, it becomes possible to make a temporary stop before reaching the collision prediction area (ACP), thereby preventing situations where right-turning vehicles (VA) obstruct the path of straight-ahead vehicles (VB).

[0217] Furthermore, in this embodiment, when a pedestrian is detected in the intersection surrounding area AAC, in addition to issuing a pedestrian warning, an alert is also issued to prompt the straight-ahead vehicle VB to pay attention to the right-turning vehicle VA. In other words, when a pedestrian is detected, an alert is issued to the right-turning vehicle VA to prompt it to pay attention to the pedestrian, while an alert is issued to the straight-ahead vehicle VB to recognize that there is a right-turning vehicle VA that may stop before the crosswalk PC3 at the destination of the right turn, due to the pedestrian warning. This makes it possible not only to avoid contact between the right-turning vehicle VA and the pedestrian, but also to avoid a collision between the straight-ahead vehicle VB and the right-turning vehicle VA that has stopped before the crosswalk PC3 due to the pedestrian warning.

[0218] Furthermore, in the notification system 1 according to this embodiment, the first mode notification and the second mode notification are performed in the right-turning vehicle VA by different voices via the speaker 141a of the HMI device 131a. In other words, the notification content read aloud in the first mode notification and the notification content read aloud in the second mode notification are different. The notification content in the first mode notification and the notification content in the second mode notification each consist of, for example, relatively short sentences. Therefore, the driver of the right-turning vehicle VA can understand these notification contents in a short time without being interrupted while driving. In other words, the driver of the right-turning vehicle VA can easily distinguish between the first mode notification and the second mode notification by the difference in voice, that is, the difference in the content of the voice notification. Therefore, the notification system 1 can accurately inform the driver, who is focused on the road ahead for driving, whether the object requiring attention is a straight-ahead vehicle VB based on a first-mode alert or a person under surveillance based on a second-mode alert, using different voice prompts, without interfering with driving.

[0219] Furthermore, in the notification system 1 according to this embodiment, the first mode notification and the second mode notification are further implemented by different displays in the right-turning vehicle VA. As shown in Figure 22, the notification content displayed in the first mode notification is information indicating the type and direction of travel (straight-ahead direction) of the other vehicle (straight-ahead vehicle VB), and as shown in Figure 23, the notification content displayed in the second mode notification is information PE indicating the presence of the monitored person, limiting it to the minimum necessary information. Therefore, the notification system 1 makes it easy for the driver of the right-turning vehicle VA to understand these notification contents. Moreover, by limiting these notification contents to the minimum necessary information, the notification contents can be displayed, for example, using relatively large illustrations or characters. Therefore, the notification system 1 can improve the driver's visibility by displaying the notification contents using relatively large illustrations or characters. In other words, the driver can easily understand the notification contents by simply glancing at the display 143a of the HMI device 131a while keeping their eyes on the road ahead. Therefore, the notification system 1 can enable the driver of the right-turning vehicle VA to more accurately understand, without interfering with driving, whether the object requiring attention is the straight-going vehicle VB based on the first mode notification or the monitored person based on the second mode notification, based on different voices as well as different displays.

[0220] Furthermore, in the notification system 1 according to this embodiment, the notification in the first mode is performed with different voices depending on whether the right-turning vehicle VA is located within the expanded intersection area ACSe or within the basic intersection area ACSb. This allows the driver of the right-turning vehicle VA to be aware of the straight-ahead vehicle VB, which is the target of attention, from the stage when the right-turning vehicle VA is located within the expanded intersection area ACSe, where the distance to the intersection CS is relatively longer and there is more margin. Therefore, the notification system 1 can enable the driver of the right-turning vehicle VA to take safer collision avoidance actions towards the straight-ahead vehicle VB when the right-turning vehicle VA reaches the intersection CS. Similarly, the driver of the straight-ahead vehicle VB can be aware of the right-turning vehicle VA, which is the target of attention, from the stage when the right-turning vehicle VA is located within the expanded intersection area ACSe, where the distance to the intersection CS is relatively longer and there is more margin. Therefore, the notification system 1 can enable the driver of the straight-ahead vehicle VB to take safer collision avoidance actions towards the right-turning vehicle VA if, by any chance, the right-turning vehicle VA attempts to turn right at the intersection CS before the straight-ahead vehicle VB has passed the intersection CS.

[0221] In the notification system 1 according to this embodiment, the second mode notification is performed with different voices depending on whether the right-turning vehicle VA is located within the extended intersection area ACSe or within the basic intersection area ACSb. This allows the driver of the right-turning vehicle VA to identify the person to be monitored, who is the target of their attention, from the stage when the right-turning vehicle VA is located within the extended intersection area ACSe, where the distance to the intersection CS is relatively longer and there is more leeway. Therefore, the notification system 1 can prompt the driver of the right-turning vehicle VA to take safer collision avoidance actions towards the person to be monitored when the right-turning vehicle VA reaches the intersection CS.

[0222] In the notification system 1 according to this embodiment, the notification of the third mode and the notification of the first mode for the straight-moving vehicle VB are performed with the same voice. Therefore, even if a person to be monitored that does not require the driver of the straight-moving vehicle VB is detected in the intersection CS or a predetermined area around the intersection AAC when the straight-moving vehicle VB passes through the intersection CS, the notification system 1 can only draw the driver of the straight-moving vehicle VB's attention to the right-turning vehicle VA that does require their attention. Thus, the notification system 1 can provide notifications that do not interfere with the driving of the straight-moving vehicle VB.

[0223] In the notification system 1 according to this embodiment, the notification in the third mode and the notification in the first mode for the straight-moving vehicle VB are performed by the same voice and the same display. Therefore, the notification system 1 can reliably provide notifications that do not interfere with the driving of the straight-moving vehicle VB.

[0224] The notification system 1 according to this embodiment includes a first notification unit B118a and a third notification unit B122a that, when a person under surveillance is detected by the pedestrian detection unit B121a while a first mode notification is being issued as an information presentation notification, enable the right-turning vehicle VA to issue a fourth mode notification via the HMI device 131a, which is different from the first mode notification and the second mode notification, by voice. Furthermore, the notification system 1 includes a second notification unit B119a and a third notification unit B122a that, when a person under surveillance is detected by the pedestrian detection unit B121a while a first mode notification is being issued as an alarm notification, enable the right-turning vehicle VA to issue a fourth mode notification via the HMI device 131a, which is different from the first mode notification and the second mode notification, by voice. Therefore, if the driver of the right-turning vehicle VA fails to notice the notification of information, or ignores the notification of information and the warning, and proceeds forward within the intersection CS, approaching the pedestrian crossing PC3, the notification system 1 can alert the driver of the right-turning vehicle VA to the presence of pedestrians through a voice-based fourth-mode notification, prompting them to slow down or come to a complete stop before the pedestrian crossing PC3.

[0225] In the notification system 1 according to this embodiment, the fourth mode notification is further implemented by display. Therefore, if the driver of a right-turning vehicle VA does not notice the notification of information presentation, or ignores the notification of information presentation and the warning, and proceeds forward within the intersection CS and approaches the pedestrian crossing PC3, the notification system 1 can make the driver of the right-turning vehicle VA aware of the presence of pedestrians by issuing a fourth mode notification based on display in addition to voice, thereby reliably prompting them to slow down or come to a complete stop before the pedestrian crossing PC3.

[0226] In the notification system 1 according to this embodiment, if, while at least an audible notification is being made, the road map storage unit B113a detects that a right-turning vehicle VA has finished passing through intersection CS, the audible notification is made until a predetermined word, phrase, or sentence representing the notification content is read aloud at least once. Therefore, the notification system 1 can avoid the notification content being cut short and allow the driver to understand the notification content more accurately.

[0227] (Other embodiments) The alarm process may be performed only when a right-turning vehicle VA and a straight-going vehicle VB are facing each other with an intersection CS in between. Specifically, the alarm process is avoided when it is expected that the straight-going vehicle VB will pass through intersection CS before the right-turning vehicle VA enters intersection CS, or that the right-turning vehicle VA will pass through intersection CS before the straight-going vehicle VB approaches intersection CS.

[0228] Figure 20 illustrates a situation in which a straight-ahead vehicle VB passes through intersection CS before a right-turning vehicle VA enters the intersection CS. In this embodiment, if the situation shown in the figure is expected to occur at the time the intention of the right-turning vehicle VA to turn right is detected, the alarm process is avoided.

[0229] Specifically, the system compares the intersection entry time ta1, when a right-turning vehicle VA reaches the intersection entry point P1a in lane L11, with the intersection exit time tb2, when a straight-going vehicle VB reaches the intersection exit point P2b in lane L22. If the intersection entry time ta1 of the right-turning vehicle VA is later than the intersection exit time tb2 of the straight-going vehicle VB, the system avoids triggering an alert. Both the intersection entry point P1a for the right-turning vehicle VA and the intersection exit point P2b for the straight-going vehicle VB can be set on the outer edge of the intersection area ACS (for example, the basic intersection area ACSb). The intersection entry time ta1 can be calculated based on road map information, the current position Pa and vehicle speed VSPa of the right-turning vehicle VA, and the intersection exit time tb2 can be calculated based on road map information, the current position Pb and vehicle speed VSPb of the straight-going vehicle VB.

[0230] In simple terms, the entry time ta1 of a right-turning vehicle VA into the intersection can be calculated using the following equation (6.1), where Da1 is the distance from the current position Pa at the time the intention to turn right is detected (time t0) to the intersection center CTR, and φacs is the radius of the intersection area ACS. The exit time tb2 of a straight-going vehicle VB from the intersection can be calculated using the following equation (6.2), where Db1 is the distance from the current position Pb at the time the intention to turn right of the right-turning vehicle VA is detected to the intersection center CTR, and φacs is the radius of the intersection area ACS. ta1=t0+(Da1-φacs) / VSPa …(6.1) tb2=t0+(Db1+φacs) / VSPb…(6.2)

[0231] Figure 21 illustrates a situation in which a right-turning vehicle VA passes through intersection CS before a straight-going vehicle VB reaches the alarm activation position. In this embodiment, in addition to the situation described above, the alarm activation process is avoided even when the situation shown in the figure is expected to occur at the time the intention of the right-turning vehicle VA to turn right is detected.

[0232] Specifically, the system compares the intersection passage time ta2, when a right-turning vehicle VA reaches exit point P2a from intersection CS, with the alert arrival time tb1, when a straight-going vehicle VB reaches a point P1b located at a predetermined alert distance from intersection CS (hereinafter referred to as the "alert implementation point"). If the alert arrival time tb1 is later than the intersection passage time ta2, the alert process is avoided. The intersection exit point P2a for the right-turning vehicle VA can be set on the outer edge of the intersection area ACS (for example, the basic intersection area ACSb), and the alert implementation point P1b for the straight-going vehicle VB can be set at a point located at an information presentation distance Dth1 from intersection CS, for example, at a point located at an information presentation distance Dth1 from the outer edge of the collision prediction area ACP. The intersection passage time ta2 can be calculated based on road map information, the current position Pa and vehicle speed VSPa of the right-turning vehicle VA, and the alert arrival time tb1 can be calculated based on road map information, the current position Pb and vehicle speed VSPb of the straight-going vehicle VB.

[0233] In simple terms, the time ta2 at which a right-turning vehicle VA passes through the intersection can be calculated using the following equation (7.1), where Da1 is the distance from its current position Pa at the time the intention to turn right is detected (time t0) to the center of the intersection CTR, and φacs is the radius of the intersection area ACS. The time tb1 at which a straight-going vehicle VB arrives at the signaling location can be calculated using the following equation (7.2), where Db2 is the distance from its current position Pb at the time the intention to turn right of the right-turning vehicle VA is detected to the collision prediction area ACP, and Dth1 is the information presentation distance. ta2=t0+(Da1+φacs) / VSPa …(7.1) tb1=t0+(Db2-Dth1) / VSPb …(7.2)

[0234] Figure 19 is a flowchart showing the overall flow of the notification control according to this embodiment. In this embodiment, the notification control can be implemented as a control that performs the steps shown in S811 to S817 in addition to the steps shown in each step of the flowchart in Figure 4.

[0235] Regarding the case where the right-turning vehicle VA is controlled by the controller 101a, the differences from the flowchart in Figure 4 will be explained in detail. After the controller 101a reads various control information used for notification control (S111), it detects another vehicle, the straight-going vehicle VB, in the oncoming lane L22 (S112), and when it detects that the right-turning vehicle VA intends to turn right (S113), in S811 it calculates the intersection entry time ta1 and intersection passing time ta2 for the right-turning vehicle VA.

[0236] In S812, the controller 101a calculates the time tb1 when the straight-moving vehicle VB arrives at the alarm location and the time tb2 when it exits the intersection.

[0237] In S813, controller 101a determines whether the intersection entry time ta1 of the right-turning vehicle VA is later than the intersection exit time tb2 of the straight-going vehicle VB. If the intersection entry time ta1 is later than the intersection exit time tb2, the process proceeds to S815; otherwise, the process proceeds to S814.

[0238] In S814, the controller 101a determines whether the time tb1 when the straight-going vehicle VB reaches the alarm location is later than the time ta2 when the right-turning vehicle VA passes through the intersection. If the time tb1 when the alarm location is reached is later than the time ta2 when the vehicle passes through the intersection, the process proceeds to S815. If it is earlier than the time ta2 when the vehicle passes through the intersection, the process shown in S114 to S119, enclosed by the dashed-dot frame A in Figure 4, is performed.

[0239] In S815, the controller 101a determines whether it has detected a person to be monitored in the intersection CS and a predetermined area surrounding it, for example, whether it has detected a pedestrian in the area AAC surrounding the intersection. If a pedestrian is detected, the process proceeds to S816; otherwise, the current control is terminated.

[0240] In S816, controller 101a issues an alert to warn pedestrians of the right-turning vehicle VA, that is, it issues a pedestrian alert.

[0241] In S817, the controller 101a notifies the straight-going vehicle VB that a pedestrian warning has been issued for the right-turning vehicle VA. This prompts the straight-going vehicle VB to recognize that there is a right-turning vehicle VA that may stop before the crosswalk PC3 at the destination of the right turn due to the issuance of a pedestrian warning, in a situation where the issuance of the warning process in steps S114 to S119 shown in the flowchart of Figure 4 is to be avoided.

[0242] Thus, while the execution of the alarm process increases the computational load on controllers 101a and 101b required for monitoring the right-turning vehicle VA and the straight-going vehicle VB (such as tracking their current positions Pa and Pb), by avoiding the execution of the alarm process when the right-turning vehicle VA and the straight-going vehicle VB are not facing each other across the intersection CS, it is possible to suppress the unnecessary execution of the alarm process and the resulting increase in computational load, thereby enabling the effective use of the computational capacity of controllers 101a and 101b by allocating the freed-up resources to other control functions.

[0243] The system then predicts the time ta2 when the right-turning vehicle VA passes through the intersection and the time tb1 when the straight-going vehicle VB arrives at the alarm location. If the arrival time tb1 is later than the intersection passage time ta2, the system detects pedestrians in the intersection surrounding area AAC and issues a pedestrian warning to the right-turning vehicle VA. Simultaneously, the system notifies the straight-going vehicle VB that the right-turning vehicle VA has issued a pedestrian warning. This allows the straight-going vehicle VB to recognize the presence of the right-turning vehicle VA, which may stop before the crosswalk PC3 at the destination of the right turn due to the pedestrian warning, thereby reducing the risk of a collision with the right-turning vehicle VA.

[0244] In the above explanation, a pedestrian warning is issued after a right-turning vehicle VA enters the intersection area ACS (extended intersection area ACSe, basic intersection area ACSb). It is also possible to issue a pedestrian warning before a right-turning vehicle VA enters the intersection area ACS. Figure 18 is a schematic diagram showing the positional relationship between the right-turning vehicle VA and the straight-ahead vehicle VB at the time the pedestrian warning is issued, as an example of such a case.

[0245] As shown in Figure 18, the pedestrian warning can also be issued before the right-turning vehicle VA reaches the intersection area ACS. For example, if the controller 101a detects a pedestrian in the intersection surrounding area AAC based on a signal from the pedestrian's smartphone after the right-turning vehicle VA indicates its intention to turn right at intersection CS by activating its right turn signal or entering the right-turn lane, the controller 101a will issue a pedestrian warning without waiting for the vehicle to enter the intersection area ACS.

[0246] In this way, by setting the timing for issuing an alert after the right-turning vehicle VA enters the intersection area ACS, and issuing an information display or warning when the alert conditions regarding the position of the straight-ahead vehicle VB are met, while issuing a pedestrian warning before the right-turning vehicle VA enters the intersection area ACS, it becomes possible to encourage the right-turning vehicle VA to pay attention to pedestrians before entering the intersection area ACS, to slow down at an early timing before or after entering the intersection area ACS, and to come to a complete stop at or near the entry point to the intersection CS. This makes it possible to more reliably avoid collisions between the right-turning vehicle VA and pedestrians, and to further reduce the situation in which the right-turning vehicle VA obstructs the path of the straight-ahead vehicle VB by stopping before the pedestrian crossing PC3 at the destination of the right turn.

[0247] In the above explanation, the distance Db from intersection CS to the straight-ahead vehicle VB was defined as the distance from the intersection of the outer edge of the collision prediction area ACP, specifically the distance from the intersection of the straight-ahead vehicle VB's travel path TRb and the circle defining the outer edge of the collision prediction area ACP (shown by a dashed line in the figure) to the straight-ahead vehicle VB. However, the distance Db may also be defined as the distance from the collision prediction point CPP to the straight-ahead vehicle VB, or the distance along the center line of the opposing lane L22 from the right-turning vehicle VA to the straight-ahead vehicle VB.

[0248] The controllers 101a and 101b, each provided in the right-turning vehicle VA or the straight-going vehicle VB, constitute the calculation unit of the notification system 1, and the controllers 101a and 101b constitute a single virtual controller. However, it is also possible to configure the system so that the road map and the computer program for notification control are stored in a roadside unit or a remote server, and the notification control is executed outside the vehicle. In this case, the right-turning vehicle VA and the straight-going vehicle VB transmit their respective vehicle position information to an external controller via vehicle-to-infrastructure communication and receive a command signal, which is the result of calculations related to control. Based on the command signal, the system then displays information or issues a warning.

[0249] Furthermore, the traffic participants targeted for notification are not limited to the right-turning vehicle VA and the straight-ahead vehicle VB, but may also include other vehicles approaching the intersection CS. Examples of such vehicles include vehicles traveling towards the intersection CS, which the right-turning vehicle VA is heading towards, in lanes other than the right-turning lane L11 and the lane running parallel to it (for example, the straight-ahead lane L12), specifically in lanes that intersect the right-turning lane L11 (i.e., intersecting vehicles). Here, vehicles other than the right-turning vehicle VA that are approaching the intersection CS and have the potential to enter the intersection CS are called "vehicles entering the intersection," and these include not only the straight-ahead vehicle VB but also intersecting vehicles.

[0250] In the road shown in Figure 12, if, in addition to the straight-ahead vehicle VB, there is also an intersecting vehicle (not shown) entering the intersection, and there is no traffic signal to regulate the passage of intersecting vehicles at intersection CS, the timing of the intersecting vehicle entering intersection CS coincides with the timing of the right-turning vehicle VA entering intersection CS, raising concerns about contact or collision between these vehicles.

[0251] In such a situation, after detecting the intention of the right-turning vehicle VA to turn right, the notification system 1 monitors the relative positional relationship between the right-turning vehicle VA and the intersecting vehicle, and, as described above, issues an alert at an appropriate timing from when the right-turning vehicle VA approaches the intersection CS until it passes through the intersection CS, according to the urgency of the situation regarding contact or collision between the right-turning vehicle VA and the intersecting vehicle. As an example, the right-turning vehicle VA and the intersecting vehicle perform information presentation processing and warning processing of the same content as the right-turning vehicle VA and the straight-ahead vehicle VB perform between these vehicles VA and VB.

[0252] The system then monitors the surrounding area AAC of the intersection, and when it detects a pedestrian or other person to be monitored in the surrounding area AAC, it issues an alert to intersecting vehicles to warn them of the person to be monitored and the right-turning vehicle VA. This makes intersecting vehicles aware of the presence of pedestrians at the crosswalk PC3 ahead of the right turn, prompting them to slow down when entering the intersection CS. The alert also causes the right-turning vehicle VA to stop temporarily before the crosswalk PC3, thus preventing obstruction of the path of its own vehicle (i.e., the intersecting vehicle) and reducing the likelihood of contact or collision between these vehicles.

[0253] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0254] 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...Human-machine interface device (HMI device), VA...Right-turning vehicle, VB...Straight-going vehicle, ACS...Intersection area, ACP...Collision prediction area, AAC...Area around intersection.

Claims

1. A vehicle turning right in the lane leading to the intersection, A vehicle notification system that provides at least an audible alert to traffic participants, including a vehicle traveling in the opposite lane to the aforementioned driving lane in the direction of the intersection, A means for detecting persons who are subject to monitoring and who are able to move on the sidewalk in a predetermined area at or around the aforementioned intersection, A first alarm means that performs a first mode alarm to avoid a collision between the right-turning vehicle and the straight-going vehicle, The system includes a second alarm means that issues a second mode alarm to the right-turning vehicle in order to avoid a collision between the right-turning vehicle and the monitored person detected by the monitored person detection means, The first mode of notification and the second mode of notification are vehicle notification systems that are performed by different voices in the vehicle making a right turn.

2. The vehicle notification system according to claim 1, wherein the notification of the first mode and the notification of the second mode are performed by different displays in the vehicle making a right turn.

3. A vehicle speed detection means for detecting the speed of the vehicle turning right, The system further includes a determination area setting means for setting an intersection area that superimposes on the path the right-turning vehicle travels when passing through the intersection, before the right-turning vehicle reaches the intersection, The determination area setting means sets an expanded intersection area that extends the intersection area toward the lane where the right-turning vehicle is located, away from the intersection, when the vehicle speed of the right-turning vehicle detected by the vehicle speed detection means is higher than a predetermined vehicle speed. The vehicle notification system according to claim 1, wherein the notification in the first mode is performed by different voices depending on whether the right-turning vehicle is located within the extended intersection area or within the intersection area other than the extended intersection area.

4. A vehicle speed detection means for detecting the speed of the vehicle turning right, The system further includes a determination area setting means for setting an intersection area that superimposes on the path the right-turning vehicle travels when passing through the intersection, before the right-turning vehicle reaches the intersection, The determination area setting means sets an expanded intersection area that extends the intersection area toward the lane where the right-turning vehicle is located, away from the intersection, when the vehicle speed of the right-turning vehicle detected by the vehicle speed detection means is higher than a predetermined vehicle speed. The vehicle notification system according to claim 1, wherein the notification of the second mode is performed by different voices depending on whether the right-turning vehicle is located within the extended intersection area or within the intersection area other than the extended intersection area.

5. The system further comprises a third alarm means that, when the second alarm means performs an alarm in the second mode, performs an alarm in the third mode to alert the straight-going vehicle to the right-turning vehicle, The vehicle notification system according to claim 1, wherein the notification of the third mode and the notification of the first mode in the straight-moving vehicle are each performed by the same voice.

6. The vehicle notification system according to claim 5, wherein the notification of the third mode and the notification of the first mode in the straight-moving vehicle are each performed by the same display.

7. The vehicle notification system according to claim 1, wherein the first notification means and the second notification means, when the monitored person detection means detects the monitored person while the first mode notification is being performed, perform a fourth mode notification by voice in the right-turning vehicle, which is different from the first mode notification and the second mode notification.

8. The vehicle notification system according to claim 7, wherein the notification of the fourth mode is performed by display.

9. The system includes a road map storage means that stores a road map including the aforementioned intersection and identifies the current position of the right-turning vehicle on the road map and the current position of the straight-going vehicle on the road map. The vehicle notification system according to any one of claims 1 to 8, wherein, while the notification by at least voice is being performed, if the right-turning vehicle is detected to have finished passing the intersection based on the identification result by the road map storage means, the notification by at least voice is performed until a predetermined word, predetermined phrase, or predetermined sentence is read aloud at least once.

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