Vehicle notification system

Abstract

A vehicle notification system that contributes to further improving traffic safety is provided. [Solution] The vehicle notification system provides information or issues a warning to traffic participants VA and VB in a traffic situation where a right-turning vehicle VA and a straight-moving vehicle VB are facing each other across an intersection CS. After detecting a right-turn intention, an intersection area ACS and a collision prediction area ACP are set before the right-turning vehicle VA reaches the intersection CS. A first notification timing is set according to the relative position of the right-turning vehicle VA with respect to the intersection area ACS, and a second notification timing is set according to the behavior of the right-turning vehicle VA in the intersection area ACS. At each of the first and second notification timings, a predetermined notification mode is issued to traffic participants, provided that a predetermined notification condition regarding the position of the straight-moving vehicle VB is met. The intersection area ACS is set to a size according to the driving state of the right-turning vehicle VA before it reaches the intersection CS.

Description

[Technical Field]

[0001] The present invention relates to a vehicle notification system. [Background technology]

[0002] There is a technology that aims to assist drivers when turning right at an intersection on a left-hand traffic road by understanding the driving conditions of other traffic participants, including oncoming vehicles traveling straight toward the intersection in the oncoming lane, and instructing the driver on the timing of the right turn to avoid a collision with an oncoming vehicle.

[0003] Here, detection of traffic participants is generally performed by an on-board sensor such as a camera or radar. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-265832 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when using an on-board sensor, it is difficult to detect traffic participants in blind spots, such as behind an obstacle.

[0006] Specifically, if there is another vehicle traveling alongside the oncoming vehicle in the same lane, or if another vehicle is stopped in front of the oncoming vehicle waiting to turn right, the other vehicle becomes an obstacle and is in the blind spot of the other vehicle, making it difficult for the onboard sensors installed in the right-turning vehicle to detect the oncoming vehicle.

[0007] If the other vehicle acting as an obstacle is a large vehicle, the blind spot will be wider, making it more difficult to detect the oncoming vehicle.

[0008] Therefore, an object of the present invention is to provide a vehicle notification system that contributes to further improving traffic safety. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, a vehicle notification system according to one aspect of the present invention is a vehicle notification system that issues an alert to traffic participants including a right-turning vehicle present in a lane leading to an intersection and a straight-moving vehicle traveling in a straight direction toward the intersection in an oncoming lane to the lane in which the right-turning vehicle is present, and includes road map storage means that stores a road map including the intersection, right-turning vehicle position identification means that identifies the current position of the right-turning vehicle on the road map, straight-moving vehicle position identification means that identifies the current position of the straight-moving vehicle on the road map, right-turn intention detection means that detects an intention of the right-turning vehicle to turn right, driving state detection means that detects a driving state of the right-turning vehicle, intersection area setting means that, after the right-turn intention has been detected and before the right-turning vehicle reaches the intersection, sets, in association with the road map, an intersection area that overlaps with a route that the right-turning vehicle will travel when passing through the intersection, and a location of the right-turning vehicle identified by the right-turning vehicle position identification means. a first alert timing setting means for setting a first alert timing according to the relative position of the right-turning vehicle with respect to the intersection area set by the intersection area setting means based on the current position of the right-turning vehicle; a second alert timing setting means for setting a second alert timing according to the behavior of the right-turning vehicle in the intersection area after the first alert timing setting means has set the first alert timing; and an alert issuing means for issuing an alert in a predetermined mode to the traffic participants on the condition that an alert condition determined with respect to the position of the straight-moving vehicle is satisfied at each of the first alert timing set by the first alert timing setting means and the second alert timing set by the second alert timing setting means, wherein the intersection area setting means sets the intersection area to a size according to the driving state of the right-turning vehicle detected by the driving state detection means before the right-turning vehicle reaches the intersection. [Effects of the Invention]

[0010] According to one aspect of the present invention, as a right-turning vehicle passes through an intersection, appropriate alert timings are set according to the relative position of the right-turning vehicle with respect to the intersection area and the behavior of the right-turning vehicle in the intersection area. At each of the set alert timings, an alert is issued in a predetermined mode if an alert condition related to the position of a straight-moving vehicle is met. This makes it possible to issue an alert in an appropriate mode at an appropriate timing according to the urgency of the situation in a situation where there is a risk of a collision between a right-turning vehicle and a straight-moving vehicle. Here, by detecting the driving state of the right-turning vehicle before it reaches the intersection and setting the intersection area to a size that corresponds to the driving state of the right-turning vehicle, the size of the intersection area can be set to a size that corresponds to the actual driving state of the right-turning vehicle, thereby optimizing the alert timing and realizing more appropriate alerts. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing an overall configuration of a vehicle notification system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram showing the internal configuration of a controller provided in a right-turning vehicle. [Figure 3] FIG. 2 is a schematic diagram showing the internal configuration of a controller provided in a straight-moving vehicle. [Figure 4] 10 is a flowchart showing the overall flow of notification control. [Figure 5] 10 is a flowchart showing the contents of an early warning process. [Figure 6] 10 is a flowchart showing the contents of early warning processing (information presentation processing). [Figure 7] 10 is a flowchart showing the contents of early warning processing (alarm processing). [Figure 8] 10 is a flowchart showing the contents of a normal alarm issuing process. [Figure 9] 10 is a flowchart showing the contents of a normal alarm process (information presentation process). [Figure 10] 10 is a flowchart showing the contents of normal alarm processing (alarm processing). [Figure 11]10A and 10B are explanatory diagrams showing a method for calculating an information presentation distance and a warning distance. [Figure 12] FIG. 2 is a schematic diagram showing an example of a traffic situation that is expected to be the subject of notification. [Figure 13] 10 is a schematic diagram showing the relationship between a right-turning vehicle and a straight-moving vehicle at the timing of issuing an information notification; FIG. [Figure 14] 10 is a schematic diagram showing the relationship between a right-turning vehicle and a straight-moving vehicle at the timing of issuing an alarm. FIG. [Figure 15] FIG. 10 is a schematic diagram showing how an expanded intersection area and an expanded predicted collision area are set. [Figure 16] FIG. 10 is a schematic diagram showing a setting state of a reduced collision prediction area. [Figure 17] 10 is a flowchart showing an overall flow of notification control according to another embodiment of the present invention. [Figure 18] 1 is a schematic diagram illustrating a situation in which a straight-moving vehicle passes through an intersection before a right-turning vehicle enters the intersection. [Figure 19] FIG. 10 is a schematic diagram showing a situation in which a vehicle turning right passes through an intersection before a vehicle going straight reaches a position where an alert is issued. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0013] (Overall configuration of vehicle notification system) FIG. 1 is a schematic diagram showing the configuration of a vehicle notification system (hereinafter, sometimes simply referred to as "notification system") 1 according to one embodiment of the present invention.

[0014] In this embodiment, a traffic situation is assumed in which a vehicle (hereinafter referred to as a "right-turning vehicle") VA traveling toward an intersection on a left-hand traffic road and another vehicle (hereinafter referred to as a "straight-moving vehicle") VB traveling straight toward the intersection in a lane (hereinafter referred to as an "oncoming lane") opposite the lane in which the right-turning vehicle VA is traveling (hereinafter referred to as a "driving lane"). The notification system 1 is applicable not only to left-hand traffic roads but also to right-hand traffic roads. In the case of right-hand traffic, the notification system 1 targets a traffic situation in which a left-turning vehicle traveling toward an intersection and a straight-moving vehicle traveling in an oncoming lane toward the intersection exist. In other words, the notification system 1 is applicable to traffic situations in which right-turning or left-turning vehicles (hereinafter referred to as "right / left-turning vehicles" or "non-straight-moving vehicles") in the driving lane and straight-moving vehicles in the oncoming lane coexist. In the case of left-hand traffic, the right-turning vehicle is a vehicle turning right at the intersection and must not obstruct the straight-moving vehicle traveling in the oncoming lane from passing through the intersection.

[0015] The notification system 1 includes a controller 101 as main elements related to this embodiment, as well as accessory devices such as vehicle sensors 111 to 113, communication devices 121 and 122, and an HMI (human machine interface) device 131.

[0016] In this embodiment, these various elements including the controller 101 are provided in each of the right-turning vehicle VA and the straight-moving vehicle VB. The controller 101a provided in the right-turning vehicle VA and the controller 101b provided in the straight-moving 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 provided in the right-turning vehicle VA and its associated devices, and can also be configured as an in-vehicle system for the straight-moving vehicle VB using the controller 101b provided in the straight-moving vehicle VB and its associated devices.

[0017] In the following description, vehicle-to-vehicle communication is performed between a right-turning vehicle VA and a straight-moving vehicle VB, and vehicle information regarding the right-turning vehicle VA can be shared between the right-turning vehicle VA and the straight-moving vehicle VB, and vehicle information regarding the straight-moving vehicle VB can be shared between these vehicles VA and VB. In this embodiment, the vehicle information to be communicated or shared between the right-turning vehicle VA and the straight-moving vehicle VB includes the current positions Pa, Pb, vehicle speeds VSPa, VSPb, right turn signal operation status (i.e., right turn signal switch output), and lane ID of each vehicle VA and VB. Communication between the right-turning vehicle VA and the straight-moving vehicle VB is not limited to direct communication via vehicle-to-vehicle communication, but can also be indirectly performed via a roadside device installed on the side of the road, a server located in a remote location, or a communication device provided in a vehicle other than the right-turning vehicle VA and the straight-moving vehicle VB.

[0018] In this embodiment, the right-turning vehicle VA and the straight-moving vehicle VB have the same basic configuration to constitute the notification system 1. The right-turning vehicle VA includes a controller 101a, vehicle sensors 111a, 112a, and 113a, communication devices 121a and 122a, and an HMI device 131a. On the other hand, the straight-moving vehicle VB includes a controller 101b, vehicle sensors 111b, 112b, and 113b, communication devices 121b and 122b, and an HMI device 131b.

[0019] The controllers 101a and 101b constitute the calculation unit of the notification system 1, and generate and output command signals according to the calculation results. The controllers 101a and 101b are constituted by a microcomputer equipped with a central processing unit (CPU), storage devices such as ROM and RAM, and an input / output interface.

[0020] The 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, as its accompanying vehicle sensors, a position sensor 111a, a vehicle speed sensor 112a, and a right blinker switch 113a, and the straight-moving vehicle VB is equipped with, as its accompanying vehicle sensors, a position sensor 111b, a vehicle speed sensor 112b, and a right blinker switch 113b.

[0021] The position sensor 111a detects the current position Pa of the right-turning vehicle VA, and the position sensor 111b detects the current position Pb of the straight-moving vehicle VB. The position sensors 111a and 111b can each be configured with a receiver for 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).

[0022] Vehicle speed sensor 112a detects the traveling speed (hereinafter referred to as "vehicle speed") VSPa of right-turning vehicle VA, and vehicle speed sensor 112b detects the vehicle speed VSPb of straight-moving vehicle VB. Vehicle speed sensors 112a and 112b can detect the wheel speeds (e.g., rotational speeds of driven wheels) of target vehicles VA and VB and convert them into traveling distance per unit time using tire dynamic radius or the like.

[0023] The right blinker switch 113a outputs an ON signal when the right turn indicator (hereinafter referred to as "right blinker") of the right-turning vehicle VA is activated, and the right blinker switch 113b outputs an ON signal when the right blinker of the straight-moving vehicle VB is activated. The activation of the right blinker switches 113a and 113b indicates that the target vehicles VA and VB intend to turn right or change lanes.

[0024] Detection signals from the position sensor 111a, the vehicle speed sensor 112a and the right blinker switch 113a are output to the controller 101a, and detection signals from the position sensor 111b, the vehicle speed sensor 112b and the right blinker switch 113b are output to the controller 101b.

[0025] The HMI devices 131a and 131b constitute the output section of the notification system 1. The HMI device 131a receives a command signal from the controller 101a and notifies the driver of the right-turning vehicle VA about the traffic conditions. The HMI device 131b receives a command signal from the controller 101b and notifies the driver of the straight-moving vehicle VB about the traffic conditions.

[0026] The notification by the HMI devices 131a and 131b may be visual or audible. The HMI devices 131a and 131b can provide notification by both display and sound, or can provide notification by either one of these. The HMI devices 131a and 131b are placed in a location that is easily visible to the driver, such as on the dashboard inside the vehicle.

[0027] In addition to the above, the right-turning vehicle VA is equipped with a transmitter 121a and a receiver 122a, and the straight-moving vehicle VB is equipped with a transmitter 121b and a receiver 122b. The transmitter 121a and the receiver 122a equipped in the right-turning vehicle VA constitute an inter-vehicle communication device for the right-turning vehicle VA, and the transmitter 121b and the receiver 122b equipped in the straight-moving vehicle VB constitute an inter-vehicle communication device for the straight-moving vehicle VB. The right-turning vehicle VA and the straight-moving vehicle VB can communicate wirelessly via each other's inter-vehicle communication devices.

[0028] As mentioned above, communication between the right-turning vehicle VA and the straight-moving vehicle VB is not limited to direct communication between the right-turning vehicle VA and the straight-moving vehicle VB, but may also be indirect communication via a roadside device, a remote server, or another vehicle.

[0029] FIG. 12 is a schematic diagram showing an example of a traffic situation that is expected to be the subject of notification according to this embodiment.

[0030] In this embodiment, a traffic situation is assumed in which a right-turning vehicle VA and a straight-moving vehicle VB are facing each other across an intersection CS. An intersection (in this embodiment, a crossroads) CS exists on a two-lane road R that includes right-turn lanes L11 and L21 and straight-moving lanes L12 and L22. The right-turning vehicle VA is in one right-turn lane L11 and is approaching the intersection CS, while the straight-moving vehicle VB is in the other straight-moving lane L22 and is traveling straight toward the intersection CS at a position 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-moving lane L22 correspond to oncoming lanes relative to the right-turning vehicle VA. The oncoming right-turn lane L21 and the straight-moving lane L22 may hereinafter be referred to as the "oncoming right-turn lane" and the "oncoming straight-moving lanes."

[0031] In addition to the right-turning vehicle VA and the straight-going vehicle VB, in the oncoming right-turn lane L21, there is a vehicle (hereinafter referred to as "waiting vehicle") VC stopped in front of the stop line SL2 ahead of the straight-going vehicle VB, waiting to turn right. In the traffic situation shown in the figure, the waiting vehicle VC is a visual obstacle that blocks part of the view from the right-turning vehicle VA and also blocks part of the view from the straight-going vehicle VB. Because the straight-going vehicle VB is in the blind spot of the waiting vehicle VC from the right-turning vehicle VA, it is difficult for the right-turning vehicle VA to see the straight-going vehicle VB, and because the right-turning vehicle VA is in the blind spot of the waiting vehicle VC from the straight-going vehicle VB, it is difficult for the straight-going vehicle VB to see the right-turning vehicle VA.

[0032] In such a 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-moving vehicle VB, and issues a notification according to the urgency of the situation regarding contact or collision between the right-turning vehicle VA and the straight-moving vehicle VB at an appropriate timing from when the right-turning vehicle VA approaches the intersection CS until when the right-turning vehicle VA passes through the intersection CS.

[0033] (Internal structure of the controller) Fig. 2 is a schematic diagram showing the internal configuration of a controller 101a provided in a right-turning vehicle VA, and Fig. 3 is a schematic diagram showing the internal configuration of a controller 101b provided in a straight-moving vehicle VB. The internal configurations of the controllers 101a and 101b will be described in order using Fig. 2 and Fig. 3, with appropriate reference to Fig. 12.

[0034] 2, the controller 101a includes a host 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 activation unit B118a, a second alarm activation unit B119a, and a judgment area setting unit B120a. The functions of these units B111a to B120a are realized in software by a central processing unit included in the controller 101a reading a computer program stored in a storage device and operating in accordance with the instructions of the program.

[0035] The host vehicle position detection unit B111a detects the current position Pa of the host vehicle, that is, the right-turning vehicle VA. The detection of the current position Pa by the host vehicle position detection unit B111a is based on an output signal from a position sensor 111a provided in the right-turning vehicle VA.

[0036] The other vehicle position detection unit B112a detects the current position Pb of the straight-moving vehicle VB, which is the other vehicle. The other vehicle position detection unit B112a detects the current position Pb by reading position information indicating the current position Pb from the vehicle information acquired from the straight-moving vehicle VB via the receiver 122a provided in the right-turning vehicle VA.

[0037] The road map storage unit B113a stores a road map. In this embodiment, the current positions Pa, Pb of the right-turning vehicle VA and the straight-going vehicle VB are represented by latitude and longitude coordinates indicating these positions Pa, Pb. The road map storage unit B113a extracts a map of an area or section including the intersection CS from the road map and identifies the current positions Pa, Pb of the right-turning vehicle VA and the straight-going vehicle VB on the road map. Identifiers (hereinafter referred to as "link IDs") corresponding to each lane leading to the intersection CS, such as right-turn lanes L11, L21 and straight-going lanes L12, L22, are assigned to the road map and 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 exists or is traveling.

[0038] The right-turn intention detection unit B114a detects that the right-turning vehicle VA has an intention to turn right. The right-turn intention detection unit B114a can detect the intention to turn right by an output signal from a right blinker switch 113a provided on the right-turning vehicle VA, or, if the right-turn lane L11 is a right-turn-only lane, by reading out the link ID associated with the current lane from the road map and detecting that the right-turning vehicle VA is in the right-turn lane L11.

[0039] 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 performed by reading vehicle speed information indicating the vehicle speed VSPb from the vehicle information acquired from the straight-moving vehicle VB via the receiver 122a provided in the right-turning vehicle VA.

[0040] Based on the current position Pa of the right-turning vehicle VA on the road map, after the right-turn intention detection unit B114a detects a right-turn intention, 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 blinker, the first alert timing setting unit B116a detects that the right-turning vehicle VA is at a predetermined relative position with respect to the intersection CS, specifically, that the right-turning vehicle VA is at a predetermined distance from or closer to the center position (hereinafter referred to as the "intersection center") CTR of the intersection CS. The first alert timing setting unit B116a then sets the timing at which it detects that the right-turning vehicle VA is at the predetermined relative position with respect to the intersection CS as the first alert timing. The first alert timing set by the first alert timing setting unit B116a is the timing at which the right-turning vehicle VA issues an alert in a first predetermined mode.

[0041] The second alert timing setting unit B117a monitors the behavior of the right-turning vehicle VA after setting the first alert timing. The second alert timing setting unit B117a determines the intersection of a route TRa along which the right-turning vehicle VA travels when passing through the intersection CS and a route TRb along which the straight-moving vehicle VB travels when passing through the intersection CS as a "predicted collision point" CPP. Based on the current position Pa of the right-turning vehicle VA on a road map, the second alert timing setting unit B117a detects whether the right-turning vehicle VA is traveling toward the predicted collision point CPP or has approached within a predetermined distance from the predicted collision point CPP after setting the first alert timing. The second alert timing setting unit B117a then sets the timing at which it detects any of these behaviors of the right-turning vehicle VA as the second alert timing. The second alert timing set by the second alert timing setting unit B117a is the timing at which the right-turning vehicle VA issues an alert in a second predetermined mode.

[0042] Fig. 13 is a schematic diagram showing the positional relationship between right-turning vehicle VA and straight-going vehicle VB at the time when right-turning vehicle VA crosses stop line SL1 in right-turn lane L11 and enters intersection CS. Fig. 13 simplifies the illustration of road R, showing only right-turn lane L11 and straight-going lane L22 of two-lane road R (the same applies to Figs. 14, 15, 16, 18, and 19 shown later).

[0043] 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 a determination area setting unit B120a, which will be described later. The intersection area ACS is set so as to overlap with the route TRa along which the right-turning vehicle VA will travel when passing through the intersection CS. After the right-turning vehicle VA indicates its intention to turn right, the system detects that the right-turning vehicle VA is at a predetermined relative position with respect to the intersection CS when the right-turning vehicle VA arrives at or enters the intersection area ACS. The intersection area ACS is set as a circular area concentric with the intersection center CTR and having a predetermined radius φacs. In each of Figures 13 to 16, 18, and 19, the intersection area ACS is indicated by a two-dot chain line, the travel route TRa of the right-turning vehicle VA is indicated by a one-dot chain line, and the collision prediction area ACP and the travel route TRb of the straight-moving vehicle VB, which will be described below, are indicated by dashed lines and one-dot chain lines, respectively.

[0044] FIG. 14 is a schematic diagram showing the positional relationship between a right-turning vehicle VA and a straight-moving vehicle VB when the right-turning vehicle VA enters the intersection CS, moves forward within the intersection CS, and approaches the intersection center CTR.

[0045] In this embodiment, a collision prediction area ACP is set as an area different from the intersection area ACS, with the collision prediction point CPP at its center. The collision prediction area ACP is set by the determination area setting unit B120a, just like the intersection area ACS. After entering the intersection area ACS, it is detected that a right-turning vehicle VA is traveling within the intersection area ACS toward the collision prediction point CPP or is present within the collision prediction area ACP. The collision prediction area ACP is set as a circular area with a predetermined radius φacp and an area smaller than that of the intersection area ACS.

[0046] The intersection area ACS is not limited to a circle, but may be a shape that resembles the area where two intersecting roads overlap (for example, a rectangle with four corners at the corners), or the shape of the area surrounded by the stop lines SL1 and SL2 installed on each of the intersecting roads.The same is true for the collision prediction area ACP, which 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 that defines the oncoming straight-through lane L22).

[0047] The first alarm unit B118a outputs a command signal to the HMI device 131a provided in the vehicle (i.e., the right-turning vehicle VA) to issue an alarm in the first predetermined mode, on the condition that a first predetermined alarm condition is met regarding the position Pb of the other vehicle, which is the straight-moving vehicle VB, at the first alarm timing set by the first alarm timing setting unit B116a.

[0048] The first predetermined alarm 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 at a position closer to the intersection CS than this. In this embodiment, the distance Db from the intersection CS to the straight-moving vehicle VB is taken as the distance from the outer edge of the collision prediction area ACP, specifically, the distance from the intersection of the travel path TRb of the straight-moving vehicle VB and a circle (indicated by a dashed line in the figures) that defines the outer edge of the collision prediction area ACP, as shown in Figures 13 and 14.

[0049] The HMI device 131a, which has received the command signal from the first alarm issuing unit B118a, issues an alarm by display and sound to prompt the driver of the right-turning vehicle VA to recognize the presence of the straight-moving vehicle VB traveling in the oncoming straight-moving lane L22 toward the intersection CS. The alarm issued by the first alarm issuing unit B118a is an alarm to present information regarding a relatively low urgency regarding a collision between the right-turning vehicle VA and the straight-moving vehicle VB.

[0050] The second alarm unit B119a outputs a command signal to the HMI device 131a to issue an alarm in a second predetermined mode, provided that a second predetermined alarm condition is met regarding the position Pb of the straight-moving vehicle VB at the second alarm timing set by the second alarm timing setting unit B117a.

[0051] The second predetermined alarm condition is that the straight-moving vehicle VB is at a second predetermined distance (hereinafter referred to as the "alarm distance") Dth2 from the intersection CS that is shorter than the information presentation distance Dth1, or is located closer to the intersection CS than this.

[0052] The second predetermined mode is a different mode from the first predetermined mode, and the HMI device 131a, having received a command signal from the second alarm unit B119a, issues an alarm by display and sound to the driver of the right-turning vehicle VA to encourage the driver to recognize a higher level of urgency regarding a collision between the right-turning vehicle VA and the straight-moving vehicle VB. The alarm issued by the second alarm unit B119a is more noticeable and appeals more to the driver's sight or hearing than the alarm issued by the first alarm unit B118a.

[0053] In addition to outputting a command signal to the HMI device 131a, the first alarm unit B118a and the second alarm unit B119a can also notify the straight-moving vehicle VB via the transmitter 121a that an alarm has been issued in each mode, and prompt the vehicle VB to issue an appropriate alarm in accordance with the urgency of the collision with its own vehicle (i.e., the right-turning vehicle VA).

[0054] FIG. 11 is an explanatory diagram showing a method for calculating the information presentation distance Dth1 and the warning distance Dth2.

[0055] 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 deceleration rates DEC1 and DEC2 that are preset according to the alarm mode, as the distance that the straight-moving vehicle VB is expected to travel before stopping after the alarm is issued, in other words, the distance required for the straight-moving vehicle VB to stop.

[0056] Specifically, the information presentation distance Dth1 is calculated by adding the estimated travel distance to each of the free-running time PRD1 and the deceleration time PRD2 based on the vehicle speed VSPb (=V1) of the straight-moving vehicle VB at the first alert timing set by the first alert timing setting unit B116a. The free-running time PRD1 is the sum of the reaction time required for the driver to recognize, judge, and operate the vehicle after the alert is issued until the driver actually applies the brakes, and the operational delay time of the system and hydraulic equipment in response to the brake operation. In this embodiment, the free-running time PRD1 is preset to a fixed time (=ΔT). The deceleration time PRD2 is the time required from when the brakes actually begin to apply until the vehicle stops, and can be calculated based on the vehicle speed VSPb and the deceleration DEC1 (PRD2=V1 / DEC1). The deceleration DEC1 is, for example, -0.1 G. In this manner, the information presentation distance Dth1 is calculated using the following equation (1): Dth1=V1×ΔT+V1×(V1 / DEC1) / 2 …(1)

[0057] Similarly, the warning distance Dth2 is calculated by adding the estimated travel distance to each of the free-running time PRD1 and the deceleration time PRD2, but a different deceleration DEC2 is used than that used to calculate the information presentation distance Dth1. The deceleration DEC2 used to calculate the warning distance is higher than the deceleration DEC1 used to calculate the information presentation distance, in other words, a deceleration having a larger absolute value than the deceleration DEC1 (|DEC1|<|DEC2|). The deceleration DEC2 is, for example, -0.2 G. 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 alert timing, but may simply be the vehicle speed VSPb at the first alert timing. Dth2=V1×ΔT+V1×(V1 / DEC2) / 2…(2)

[0058] The determination area setting unit B120a sets an intersection area ACS and a collision prediction area ACP. That is, the determination area setting unit B120a has both the function of setting the intersection area ACS and the function of setting the collision prediction area ACP. The determination area setting unit B120a sets these areas ACS and ACP in association with a road map, and in this embodiment, sets them on the map of the range or section extracted by the road map storage unit B113a.

[0059] The intersection area ACS and the collision prediction area ACP can both be set to variable sizes. In this embodiment, the intersection area ACS and the collision prediction area ACP are both set as circular areas, and their radii, i.e., the distances φacs and φacp from the intersection center CTR and the collision prediction point CPP to the outer edges of the ACS and ACP areas, respectively, can be changed. The centers of the ACS and ACP areas are not enlarged and are maintained at the intersection center CTR and the collision prediction point CPP before and after the radius is changed.

[0060] The determination area setting unit B120a sets an intersection area ACS and also sets a collision prediction area ACP at a timing after the right-turning vehicle VA indicates its intention to turn right and before it reaches the intersection CS. After setting each area ACS and ACP, the determination area setting unit B120a changes the size of the collision prediction area ACP according to the actual driving state of the right-turning vehicle VA in the intersection area ACS at a timing when the right-turning vehicle VA reaches the intersection area ACS or after it has reached the intersection area ACS.

[0061] Specifically, the determination 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 the right-turning vehicle VA reaches the intersection CS, and sets the intersection area ACS to a larger size as the vehicle speed VSPa increases. On the other hand, the determination area setting unit B120a sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA in the intersection area ACS when the right-turning vehicle VA reaches or after the right-turning vehicle VA has reached the intersection area ACS, and sets the collision prediction area ACP to a smaller size as the vehicle speed VSPa decreases.

[0062] In this embodiment, a collision prediction area ACP is set in conjunction with the setting of the intersection area ACS before the vehicle reaches the intersection CS. If the vehicle speed VSPa at or after reaching the intersection area ACS is higher than a predetermined vehicle speed Vth2 equivalent to a slow-moving speed, the size of the collision prediction area ACP is maintained. However, if the vehicle speed VSPa is equal to or lower than the predetermined vehicle speed Vth2 and the right-turning vehicle VA is moving slowly or has stopped temporarily within the intersection area ACS, the collision prediction area ACP is reduced. In this embodiment, the collision prediction area ACP is reduced to the smallest size possible.

[0063] FIG. 15 is a schematic diagram showing the setting situation when the intersection area ACS and the collision prediction area ACP are enlarged.

[0064] The determination area setting unit B120a sets the intersection area ACS and the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA before it reaches the intersection CS. The intersection area ACS and the collision prediction area ACP are set when the right-turning vehicle VA is in a position away from the intersection CS, and in this embodiment, the setting of the width radii φacs and φacp of the areas ACS and ACP is based on the vehicle speed VSPa of the right-turning vehicle VA and the warning advance time corresponding to the vehicle speed VSPb of the straight-moving vehicle VB.

[0065] The determination area setting unit B120a has preset decelerations DEC1 and DEC2, and detects the vehicle speeds VSPa and VSPb of the right-turning vehicle VA and the straight-moving vehicle VB, respectively, at the timing shown in Fig. 15 before the right-turning vehicle VA reaches the intersection CS. In this embodiment, the decelerations DEC1 and DEC2 are the same as the predetermined decelerations DEC1 and DEC2 used to calculate the information presentation distance Dth1 and the warning distance Dth2 described above, and the deceleration DEC2 is higher than the deceleration DEC1.

[0066] 11, the judgment area setting unit B120a calculates a first alert pre-activation time PRD22, which is the time until the vehicle speed VSPb of the straight-moving vehicle VB decreases from the current vehicle speed (=V1) to 0 at a deceleration DEC1, and also calculates a second alert pre-activation time PRD21, which is the time until the vehicle speed VSPb of the straight-moving vehicle VB decreases from the current vehicle speed V1 to 0 at a deceleration DEC2. The first and second alert pre-activation times PRD22 and PRD21 are calculated using the following equations (3.1) and (3.2). Taking into account the free-running time ΔT after the alert is activated, the calculations may also be performed using the following equations (4.1) and (4.2). PRD22=VSPb / DEC1 …(3.1) PRD21=VSPb / DEC2 …(3.2) PRD22=ΔT+VSPb / DEC1 …(4.1) PRD21=ΔT+VSPb / DEC2 …(4.2)

[0067] Then, the judgment area setting unit B120a multiplies each of the first and second alert advance times PRD22 and PRD21 by the vehicle speed VSPa of the right-turning vehicle VA, and sets the obtained distances as the radii φacs and φacp of the intersection area ACS and the collision prediction area ACP. φacs=PRD22×VSPa …(5.1) φacp=PRD21×VSPa …(5.2)

[0068] FIG. 16 is a schematic diagram showing a setting state when the collision prediction area ACP is reduced.

[0069] As described above, in this embodiment, if the right-turning vehicle VA is moving slowly or stops temporarily after entering the intersection area ACS and before reaching the collision prediction area ACP, the collision prediction area ACP is reduced to its smallest size in the setting. The minimum collision prediction area ACP has a diameter that is approximately equal to the lane width W of the lane in which the straight-moving vehicle VB is traveling, i.e., the straight-moving lane L22 (φacp×2=W).

[0070] In this embodiment, the controller 101a provided in the right-turning vehicle VA and the controller 101b provided in the straight-moving vehicle VB basically have the same configuration and have corresponding elements.

[0071] 3, the controller 101b includes a host vehicle position detection unit B111b, an other vehicle position detection unit B112b, a road map storage unit B113b, a right turn intention detection unit B114b, a driving state detection unit B115b, a first alarm timing setting unit B116b, a second alarm timing setting unit B117b, a first alarm activation unit B118b, a second alarm activation unit B119b, and a judgment area setting unit B120b. The internal configuration of the controller 101b will be described below, focusing on the differences from the controller 101a.

[0072] The host vehicle position detection unit B111b detects the current position Pb of the host vehicle, i.e., the straight-moving vehicle VB, and the detection of the current position Pb is based on an output signal from a position sensor 111b provided in the straight-moving vehicle VB.

[0073] The other vehicle position detection unit B112b detects the current position Pa of the other vehicle, the right-turning vehicle VA, and 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 provided in the straight-moving vehicle VB.

[0074] Similar to the road map storage unit B113a, the road map storage unit B113b stores a road map that includes an intersection CS and to which link IDs of the lanes leading to the intersection CS are assigned, and identifies the current positions Pb and Pa of the straight-moving vehicle VB and the right-turning vehicle VA on the road map. The road maps stored in the road map storage units B113b and B113a may have different accuracy, but in this embodiment, both road maps have an accuracy that is compatible with satellite positioning using GNSS.

[0075] The right-turn intention detection unit B114b detects the right-turning vehicle VA's intention to turn right, and detects the right-turning intention by identifying the link ID of the lane in which the right-turning vehicle VA is located from the current position Pa of the right-turning vehicle VA, or by reading information indicating the operation status of the right blinker from the vehicle information acquired from the right-turning vehicle VA via the receiver 122b. It is also possible to include the link IDs of the lanes in which each vehicle VA and VB are located in the vehicle information exchanged between the straight-moving vehicle VB and the right-turning vehicle VA, and to detect the right-turning vehicle VA's intention to turn right based on the link ID acquired through communication.

[0076] 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, and the vehicle speed VSPa is detected by reading vehicle speed information indicating the vehicle speed VSPa from the vehicle information obtained from the right-turning vehicle VA via the receiver 122b.

[0077] The first alert 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 is at a predetermined relative position with respect to the intersection CS after indicating its intention to turn right. Specifically, as described above, the first alert timing setting unit B116b compares the current position Pa of the right-turning vehicle VA with the intersection area ACS and detects that the right-turning vehicle VA has reached or entered the intersection area ACS. The first alert timing setting unit B116b then sets the timing of this detection as the first alert timing. The first alert timing set by the first alert timing setting unit B116b is the timing at which an alert in the first predetermined mode is issued for the straight-moving vehicle VB.

[0078] The size and shape of the intersection area ACS may be the same or different between the controller 101a and the 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 tendency of the driving state when passing through the intersection CS.

[0079] The second alert timing setting unit B117b monitors the behavior of the right-turning vehicle VA after entering the intersection CS based on its current position Pa on the road map, and detects that after entering the intersection area ACS, the right-turning vehicle VA is traveling within the intersection area ACS toward the predicted collision point CPP or is present within the predicted collision area ACP.The second alert timing setting unit B117b then sets the timing at which either of these behaviors of the right-turning vehicle VA is detected as the second alert timing.The second alert timing set by the second alert timing setting unit B117b is the timing at which an alert in the second predetermined mode is issued for the straight-moving vehicle VB.

[0080] The size and shape of the collision prediction area ACP may be different between the controller 101a and the controller 101b, but in this embodiment, they are set to the same size and shape. The collision prediction area ACP may be set to the same size and shape in each of the controllers 101a and 101b, or may be set by notifying the coordinate information of the collision prediction area ACP set by one of the controllers 101a and 101b to the other controller via vehicle-to-vehicle communication.

[0081] The first alert unit B118b outputs a command signal to the HMI device 131b provided in the host vehicle (i.e., the straight-moving vehicle VB) to issue an alert in a first predetermined mode, on the condition that a first predetermined alert condition related to the position Pb of the straight-moving vehicle VB is satisfied at the first alert timing set by the first alert timing setting unit B116b. As described above, the first predetermined alert condition is that the straight-moving vehicle VB is located at an information presentation distance Dth1 from the intersection CS or closer to the intersection CS than this.

[0082] The HMI device 131b, which has received the command signal from the first alarm issuing unit B118b, issues an alarm by display and sound to the driver of the straight-moving vehicle VB to prompt the driver to be aware that there is a right-turning vehicle VA that should be watched out for in the oncoming right-turn lane L11. As described above, the alarm issued by the first alarm issuing unit B118b is an alarm to present information regarding a relatively low urgency regarding a collision between the straight-moving vehicle VB and the right-turning vehicle VA.

[0083] The second alarm unit B119b outputs a command signal to the HMI device 131b to issue an alarm in a second predetermined mode, on the condition that a second predetermined alarm condition related to the position Pb of the straight-moving vehicle VB is satisfied at the second alarm timing set by the second alarm timing setting unit B117b. The second predetermined alarm condition is that the straight-moving vehicle VB is at an alarm distance Dth2 from the intersection CS or closer to the intersection CS.

[0084] The HMI device 131b, which has received the command signal from the second alarm issuing unit B119b, issues a visual and audio alert to the driver of the straight-moving vehicle VB to encourage greater awareness of the urgency of the collision between the straight-moving vehicle VB and the right-turning vehicle VA. The alert issued by the second alarm issuing unit B119b is similar to that described above, and is an alert that is more noticeable and appeals more to the driver's visual or auditory senses.

[0085] The information presentation distance Dth1 and the warning distance Dth2 may be set to the same distance or different distances by the controller 101a and the controller 101b. For example, the deceleration when the straight-moving vehicle VB actually decelerates in response to the warning is learned, and the deceleration when calculating these distances Dth1 and Dth2 is corrected using a learned value that indicates the actual deceleration. Specifically, if the actual deceleration in response to the warning tends to be slower than the deceleration DEC2, the decelerations DEC1 and DEC2 are corrected downward, allowing the information presentation and warning to be issued at an earlier timing.

[0086] In addition to outputting a command signal to the HMI device 131b, the first alarm issuing unit B118b and the second alarm issuing unit B119b can also notify the right-turning vehicle VA via the transmitter 121b that an alarm has been issued in each mode.

[0087] The determination area setting unit B120b sets an intersection area ACS and a collision prediction area ACP. As described above, the determination area setting unit B120b has both the function of setting the intersection area ACS and the function of setting the collision prediction area ACP, and sets these areas ACS and ACP on the map of the range or section extracted by the road map storage unit B113b.

[0088] The size of the intersection area ACS and the collision prediction area ACP can also be variably set in the controller 101b, and 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 the collision prediction point CPP to the outer edges of each area ACS and ACP, can be changed.

[0089] The determination area setting unit B120b sets an intersection area ACS and a collision prediction area ACP at a timing after detecting the right-turning vehicle VA's intention to turn right and before the right-turning vehicle VA reaches the intersection CS.

[0090] In this embodiment, the intersection area ACS and the collision prediction area ACP are set by the determination area setting unit B120b in the same manner as the determination area setting unit B120a sets the areas ACS and ACP.

[0091] Specifically, the determination area setting unit B120b sets the intersection area ACS to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA before the right-turning vehicle VA arrives at the intersection CS, and 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 size corresponding to the vehicle speed VSPa of the right-turning vehicle VA in the intersection area ACS, and sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and sets the collision prediction area ACP to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, and

[0092] (Contents of notification control for right-turning vehicles) 4 to 10 are flowcharts showing the details of notification control executed by the controller 101a provided in the right-turning vehicle VA. The flowchart in FIG. 4 shows the overall flow of the notification control, the flowcharts in FIGS. 5 to 7 show the details of the early notification process, and the flowcharts in FIGS. 8 to 10 show the details of the normal notification process. FIGS. 6 and 9 show the details of the process (information presentation process) performed by the right-turning vehicle VA regarding information presentation, and the flowcharts in FIGS. 7 and 10 show the details of the process (alarm process) performed by the right-turning vehicle VA regarding an alarm. The information presentation process and the alarm process are executed as part of the notification control. When the controller 101a detects an intersection CS on the road ahead of its own vehicle (i.e., the right-turning vehicle VA), it executes the notification control at predetermined time intervals.

[0093] In the flowchart shown in Fig. 4, various control information used for notification control is read in S111. The control information read in S111 includes the current position Pa, vehicle speed VSPa, and link ID of the right-turning vehicle VA, which is the subject vehicle, and the current position Pb, vehicle speed VSPb, and link ID of the straight-moving vehicle VB, which is the other vehicle. The control information may also include information regarding the operation status of the right blinker of the right-turning vehicle VA and the straight-moving vehicle VB.

[0094] In S112, it is determined whether a straight-moving vehicle VB has been detected traveling straight toward the intersection CS in the oncoming lane L22, which is opposite the lane L11 in which the right-turning vehicle VA is located. The straight-moving vehicle VB is detected based on the link ID of the straight-moving vehicle VB. If the straight-moving vehicle VB is detected, the process proceeds to S113; if not, the current control is terminated.

[0095] In S113, it is determined whether or not a right-turning intention of the right-turning vehicle VA has been detected. The detection of a right-turning intention is based on the operation status of the right blinker of the right-turning vehicle VA. In addition to or instead of this, it is also possible to make the determination based on the link ID of the right-turning vehicle VA. If a right-turning intention is detected, the process proceeds to S114; if not, the current control ends.

[0096] In S114, the vehicle speed VSPa of the right-turning vehicle VA is read in. When the intention to turn right is detected, the right-turning vehicle VA is located away from the intersection CS, i.e., is located before reaching the intersection CS, and the vehicle speed VSPa when the intention to turn right is detected is the vehicle speed VSPa of the right-turning vehicle VA before reaching the intersection CS.

[0097] In S115, the vehicle speed VSPb of the straight-moving vehicle VB, specifically, the vehicle speed VSPb at the time when the right-turning vehicle VA's intention to turn right is detected, is read.

[0098] In S116, an intersection area ACS and a collision prediction area ACP are set as the judgment areas. The intersection area ACS and the collision prediction area ACP are both set based on the vehicle speed VSPa of the right-turning vehicle VA and the vehicle speed VSPb of the straight-moving vehicle VB at the time when the right-turn intention is detected. In this embodiment, the processing is simplified, and when the vehicle speed VSPa is higher than a predetermined vehicle speed, a judgment area with enlarged control radii φacs and φacp (hereinafter referred to as an "enlarged judgment area") is set, and when the vehicle speed is equal to or lower than the predetermined vehicle speed, a judgment area with normal enlarged control radii φacs and φacp is set.

[0099] In S117, it is determined whether or not an extended determination area has been set. If an extended determination area has been set, the process proceeds to S118, and if an extended determination area has not been set, the process proceeds to S119.

[0100] In S118, early alarm processing is performed using the expanded determination area.

[0101] In S119, normal alarm processing is performed in the normal determination area.

[0102] 5, various control information used in the early warning process is read in S211. The control information read in 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-moving vehicle VB.

[0103] In S212, the current position Pa of the right-turning vehicle VA on the road map is identified.

[0104] In S213, it is determined whether the right-turning vehicle VA has entered the extended intersection area ACS. The extended intersection area ACS is wider and has a larger radius φacs than the intersection area ACS for normal alarm activation, which will be described later. If the right-turning vehicle VA is located on the outer edge of the extended intersection area ACS or closer to the intersection center CTR than this position, it is determined that it has entered the extended intersection area ACS, and the process proceeds to S214. If the right-turning vehicle VA is located farther from the intersection center CTR than the outer edge of the extended intersection area ACS, it is determined that it has not entered the extended intersection area ACS, and the current control ends.

[0105] In S214, the information presentation process for early warning is performed according to the procedure shown in the flowchart of FIG.

[0106] In S215, an early warning process is carried out according to the procedure shown in the flowchart of FIG.

[0107] In S216, it is determined whether the right-turning vehicle VA has passed through the intersection CS. The determination of whether the right-turning vehicle VA has passed through the intersection CS is made when the right-turning vehicle VA departs from the extended intersection area ACS in the direction of travel after turning right. If the right-turning vehicle VA has departed from the extended intersection area ACS, it is determined that the vehicle has passed through the intersection CS, and the current control is terminated. If the vehicle is still within the extended intersection area ACS, it is determined that the vehicle has not passed through the intersection CS, and the process returns to S214, where the information presentation process and the warning process are repeatedly executed until the vehicle VA departs from the extended intersection area ACS.

[0108] 6, various control information used in the information presentation process is read in S311. The control information read in 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-moving vehicle VB.

[0109] In S312, the current positions Pa and Pb on the road map of the right-turning vehicle VA and the straight-going vehicle VB are identified.

[0110] In S313, it is determined whether the right-turning vehicle VA is outside the expanded collision prediction area ACP. The expanded collision prediction area ACP is wider and has a larger radius φacp than the collision prediction area ACP for normal alert issuance, which will be described later. If the right-turning vehicle VA is located between the outer edge of the expanded intersection area ACS and the outer edge of the expanded collision prediction area ACP, it is determined to be outside the expanded collision prediction area ACP, and the process proceeds to S314. If the right-turning vehicle VA is located on the outer edge of the expanded collision prediction area ACP or closer to the predicted collision point CPP, it is determined to not be outside the expanded collision prediction area ACP, and the information presentation process ends.

[0111] In S314, the distance from the intersection CS to the straight-moving vehicle VB, in other words, the distance Db remaining ahead of the straight-moving vehicle VB before reaching the intersection CS (hereinafter referred to as "intersection arrival distance") is calculated. As shown in Fig. 13, the intersection arrival distance Db is calculated as the distance from the outer edge of the collision prediction area ACP, or from the outer edge of the expanded collision prediction area ACP in the case of early warning issuance, to the straight-moving vehicle VB.

[0112] In S315, the vehicle speed VSPb of the straight-moving vehicle VB is read.

[0113] In S316, 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, according to the above formula (1).

[0114] In S317, it is determined whether the intersection arrival distance Db of the straight-moving vehicle VB is equal to or less than the information presentation distance Dth1, in other words, whether the straight-moving vehicle VB is at the information presentation distance Dth1 from the intersection CS or is at a position even closer to the intersection CS. If it is equal to or less than the information presentation distance Dth1, the process proceeds to S318, and if it is longer than the information presentation distance Dth1, the information presentation process ends.

[0115] In S318, a notification of information presentation is issued.

[0116] 7, various control information used in the early warning process is read in at S411. The control information read in 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-moving vehicle VB.

[0117] In S412, the current positions Pa and Pb on the road map of the right-turning vehicle VA and the straight-going vehicle VB are identified.

[0118] In S413, it is determined whether the right-turning vehicle VA is within the expanded collision prediction area ACP. If the right-turning vehicle VA is located on the outer edge of the expanded collision prediction area ACP or closer to the collision prediction point CPP than this, it is determined that the right-turning vehicle VA is within the expanded collision prediction area ACP, and the process proceeds to S414. On the other hand, if the right-turning vehicle VA is located farther from the collision prediction point CPP than the outer edge of the expanded collision prediction area ACP, it is determined that the right-turning vehicle VA is not within the expanded collision prediction area ACP, and the warning process ends.

[0119] In S414, the distance Db to the intersection of the vehicle VB going straight is calculated.

[0120] In S415, the vehicle speed VSPb of the straight-moving vehicle VB is read.

[0121] In S416, the warning distance Dth2 is calculated based on the vehicle speed VSPb of the straight-moving vehicle VB and the second predetermined deceleration DEC2, specifically, by the above formula (2).

[0122] In S417, it is determined whether the intersection arrival distance Db of the straight-moving vehicle VB is equal to or less than the warning distance Dth2, in other words, whether the straight-moving vehicle VB is at the warning distance Dth2 from the intersection CS or is at a position even closer to the intersection CS. If it is equal to or less than the warning distance Dth2, the process proceeds to S418, and if it is longer than the warning distance Dth2, the warning process is terminated.

[0123] In S418, an alarm is issued.

[0124] 8, various control information used in normal alarm processing is read in at S511. The control information read in at S511 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-moving vehicle VB.

[0125] In S512, the current position Pa of the right-turning vehicle VA on the road map is identified.

[0126] In S513, it is determined whether the right-turning vehicle VA has entered the intersection area ACS. If the right-turning vehicle VA is located on the outer edge of the intersection area ACS or closer to the intersection center CTR than this position, it is determined that it has entered the intersection area ACS, and the process proceeds to S514. If the right-turning vehicle VA is located farther from the intersection center CTR than the outer edge of the intersection area ACS, it is determined that it has not entered the intersection area ACS, and the current control ends.

[0127] In S514, information presentation processing for normal alert is performed according to the procedure shown in the flowchart of FIG.

[0128] In S515, alarm processing for normal alarm is carried out according to the procedure shown in the flowchart of FIG.

[0129] In S516, it is determined whether the right-turning vehicle VA has passed through the intersection CS. The determination of whether the right-turning vehicle VA has passed through the intersection CS is made based on whether the right-turning vehicle VA has departed from the intersection area ACS in the direction of travel after turning right. If the right-turning vehicle VA has departed from the intersection area ACS, it is determined that the vehicle has passed through the intersection CS, and the current control is terminated. If the vehicle is still within the intersection area ACS, it is determined that the vehicle has not passed through the intersection CS, and the process returns to S514, where the information presentation process and the warning process are repeatedly executed until the vehicle VA departs from the intersection area ACS.

[0130] 9, various control information used in the information presentation process is read in S611. The control information read in 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-moving vehicle VB.

[0131] In S612, the current positions Pa and Pb on the road map of the right-turning vehicle VA and the straight-going vehicle VB are identified.

[0132] In S613, it is determined 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 S614. 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 it is not outside the collision prediction area ACP, and the information presentation process ends.

[0133] In step S614, the vehicle speed VSPa of the right-turning vehicle VA is read.

[0134] In S615, it is determined whether the vehicle speed VSPa of the right-turning vehicle VA is equal to or less than a first predetermined vehicle speed Vth1. If the vehicle speed VSPa is equal to or less than the first predetermined vehicle speed Vth1, it is determined that the first alarm is being issued, and the process proceeds to S616. If the vehicle speed Vth1 is higher than the first predetermined vehicle speed Vth1, the process terminates the information presentation process. The first predetermined vehicle speed Vth1 is set based on whether or not a sufficient time is available for effective issuance of the information presentation. At a vehicle speed VSPa equal to or less than the first predetermined vehicle speed Vth1, such a sufficient time is available. At a vehicle speed VSPa exceeding this speed, however, such a sufficient time is not available. Therefore, it is determined that a situation exists in which an alarm should be issued when the right-turning vehicle VA has reached the predicted collision area ACP or when the straight-moving vehicle VB is approaching the predicted collision area ACP. The first predetermined vehicle speed Vth1 is, for example, 20 km / h.

[0135] In this way, in this embodiment, when the right-turning vehicle VA enters the intersection area ACS at a relatively low vehicle speed VSPa by temporarily stopping at the stop line SL1 just before the intersection CS or by sufficiently decelerating before entering the intersection area ACS, the detection of such a situation determines that it is the timing to issue an alert for information presentation (i.e., the first alert timing), and performs the processing from S616 onwards to determine whether the first predetermined alert condition is met. The timing to issue an alert for information presentation is not limited to this, and it can also be set when the right-turning vehicle VA has entered the intersection area ACS, in other words, when it is within the intersection area ACS, without imposing any restrictions based on the driving state such as the vehicle speed VSPa.

[0136] In S616, the distance Db to the intersection of the vehicle VB traveling straight ahead is calculated.

[0137] In S617, the vehicle speed VSPb of the straight-moving vehicle VB is read.

[0138] In S618, the information presentation distance Dth1 is calculated.

[0139] In S219, it is determined whether the intersection arrival distance Db of the straight-moving vehicle VB is equal to or shorter than the information presentation distance Dth1. If it is equal to or shorter than the information presentation distance Dth1, the process proceeds to S620, and if it is longer than the information presentation distance Dth1, the information presentation process ends.

[0140] In S620, a notification is issued to present information.

[0141] 10, various control information used in normal alarm processing is read in at S711. The control information read in 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-moving vehicle VB.

[0142] In S712, the current positions Pa and Pb on the road map of the right-turning vehicle VA and the straight-going vehicle VB are identified.

[0143] In S713, the vehicle speed VSPa of the right-turning vehicle VA is read.

[0144] In S714, it is determined whether the vehicle speed VSPa of the right-turning vehicle VA is higher than a second predetermined vehicle speed Vth2. If it is higher than the second predetermined vehicle speed Vth2, proceed to S716. If it is equal to or lower than the second predetermined vehicle speed Vth2, proceed to S715. The second predetermined vehicle speed Vth1 is set to a vehicle speed that indicates when the right-turning vehicle VA is traveling at a low speed, for example, slowly. If the vehicle speed VSPa is equal to or lower than the second predetermined vehicle speed Vth2, it is determined 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 situation and other traffic participants when passing through the intersection CS. The second predetermined vehicle speed Vth2 is, for example, 5 km / h.

[0145] In S715, the collision prediction area ACP is reduced. In this embodiment, the collision prediction area ACP is reduced to the smallest size possible, and set to a diameter that is approximately equal to the lane width W of the straight lane L22 in which the straight-moving vehicle VB is traveling.

[0146] In S716, it is determined whether the right-turning vehicle VA is within the collision prediction area ACP. If it is within the collision prediction area ACP, the process proceeds to S718, and if it is not within the collision prediction area ACP, the process proceeds to S717.

[0147] In S717, it is determined whether the vehicle speed VSPa of the right-turning vehicle VA is higher than a first predetermined vehicle speed Vth1. If it is higher than the first predetermined vehicle speed Vth1, the process proceeds to S718, and if it is equal to or lower than the first predetermined vehicle speed Vth1, the warning process ends. If the right-turning vehicle VA is not within the collision prediction area ACP and the vehicle speed VSPa is equal to or lower than the first predetermined vehicle speed Vth1, an information presentation is issued by the information presentation process (S615 in the flowchart shown in FIG. 9).

[0148] In this way, in S714 to S717, if the right-turning vehicle VA enters the intersection area ACS and then reaches the collision prediction area ACP, and is already within the collision prediction area ACP, or is outside the collision prediction area ACP but is traveling toward the collision prediction point CPP at a speed above a certain level and is approaching the collision prediction area ACP, the detection of such a situation determines that it is time to issue an alarm (i.e., the second alarm timing), and processing from S718 onwards is carried out to determine whether the second specified alarm condition is met.

[0149] In S718, the distance Db to the intersection of the vehicle VB going straight is calculated.

[0150] In S719, the vehicle speed VSPb of the straight-moving vehicle VB is read.

[0151] In S720, the warning distance Dth2 is calculated.

[0152] In S721, it is determined whether the intersection arrival distance Db of the straight-moving vehicle VB is equal to or shorter than the warning distance Dth2. If it is equal to or shorter than the warning distance Dth2, the process proceeds to S722, and if it is longer than the warning distance Dth2, the warning process ends.

[0153] In S722, an alarm is issued.

[0154] The information presentation during early alerting and the information presentation during normal alerting can be in different formats, but in this embodiment they are in the same format (for example, the same display and sound).The same applies to the issuance of alarms; the information presentation during early alerting and normal alerting can be in the same format or different formats.

[0155] (Contents of notification control for straight-moving vehicles) When the controller 101b detects an intersection CS on the road ahead of the vehicle (i.e., the straight-moving vehicle VB), the controller 101b executes notification control at predetermined time intervals. The execution cycles of the notification control of the controller 101a and the controller 101b may be the same or different. Furthermore, the notification control of both the controllers 101a and 101b may be executed in synchronization with each other.

[0156] The steps executed by the controller 101a and the controller 101b regarding notification control correspond to each other. Therefore, the notification control executed by the controller 101b will be described with reference to the flowcharts shown in FIGS.

[0157] After starting the notification control, the controller 101b reads various control information used for the notification control (S111 shown in the flowchart of FIG. 4). After detecting another vehicle in the oncoming right-turn lane L11, i.e., the right-turning vehicle VA (S112), the controller 101b determines whether or not it has detected the right-turning vehicle VA's intention to turn right (S113). If it has detected the right-turning intention, it reads the vehicle speed VSPb of the vehicle VB going straight, which is the subject vehicle, 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 speeds VSPa and VSPb (S116). As with the above, the process is simplified so that if the vehicle speed VSPa is higher than a predetermined vehicle speed, an extended determination area with relatively large radii φacs and φacp is set, and if the vehicle speed VSPa is equal to or lower than the predetermined vehicle speed, a determination area with smaller radii φacs and φacp is set. If an expanded determination area is set, early alarm processing is performed (S118), and otherwise normal alarm processing is performed (S119).

[0158] In the early warning process, after reading various control information (S211 shown in the flowchart of FIG. 5), the current position Pa of the right-turning vehicle VA on the road map is identified (S212), and it is determined whether the right-turning vehicle VA has entered the extended intersection area ACS (S213). If the right-turning vehicle VA has entered the extended intersection area ACS, the process continues and information presentation processing and warning processing are performed (S214, S215). If the right-turning vehicle VA has not entered the extended intersection area ACS, the current control is terminated. The information presentation processing and warning processing are repeatedly performed until the right-turning vehicle VA passes through the extended intersection area ACS (S216).

[0159] In the information presentation process for early alert, after various control information is read (S311 shown in the flowchart of FIG. 6), the current positions Pb and Pa of the straight-moving vehicle VB and the right-turning vehicle VA on the road map are identified (S312). It is determined whether the right-turning vehicle VA is outside the expanded collision prediction area ACP (S313). If it is determined that the right-turning vehicle VA is outside the expanded collision prediction area ACP, an intersection arrival distance Db of the straight-moving vehicle VB is calculated (S314), and an information presentation distance Dth1 corresponding to the vehicle speed VSPb of the straight-moving vehicle VB is calculated (S315, S316). If the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S317), an information presentation is issued (S318).

[0160] In the warning process for early warning, after reading various control information (S411 shown in the flowchart of FIG. 7), the current positions Pb, Pa of the straight-moving vehicle VB and the right-turning vehicle VA on the road map are identified (S412). It is determined whether the right-turning vehicle VA is within the expanded collision prediction area ACP (S413). If it is determined that the right-turning vehicle VA is within the expanded collision prediction area ACP, the intersection arrival distance Db of the straight-moving vehicle VB is calculated (S414), and the warning distance Dth2 corresponding to the vehicle speed VSPb of the straight-moving vehicle VB is calculated (S415, S416). If the intersection arrival distance Db is equal to or less than the warning distance Dth2 (S417), a warning is issued (S418).

[0161] In the normal alarm processing, after various control information is read (S511 shown in the flowchart of FIG. 8), the current position Pa of the right-turning vehicle VA on the road map is identified (S512), and it is determined whether the right-turning vehicle VA has entered the intersection area ACS (S513). If the right-turning vehicle VA has entered the intersection area ACS, the processing continues and information presentation processing and alarm processing are performed (S514, S515). If the right-turning vehicle VA has not entered the intersection area ACS, the current control is terminated. The information presentation processing and alarm processing are repeatedly performed until the right-turning vehicle VA passes through the intersection area ACS (S516).

[0162] In the information presentation process for normal alerts, various control information is read (S611 shown in the flowchart of FIG. 9 ), and then the current positions Pb and Pa of the straight-moving vehicle VB and the right-turning vehicle VA on the road map are identified (S612). It is determined whether the right-turning vehicle VA is outside the collision prediction area ACP (S613). If it is determined that the right-turning vehicle VA is outside the collision prediction area ACP, the vehicle speed VSPa of the right-turning vehicle VA is read (S614) and it is determined whether the vehicle speed VSPa is equal to or less than a first predetermined vehicle speed Vth1 (S615). If the vehicle speed is equal to or less than the first predetermined vehicle speed Vth1, the system calculates the intersection arrival distance Db of the straight-moving vehicle VB (S616), and calculates an information presentation distance Dth1 corresponding to the vehicle speed VSPb of the straight-moving vehicle VB (S617, S618). If the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S619), an information presentation is issued (S620).

[0163] In the normal warning process, various control information is read (S711 in the flowchart of FIG. 10), and then the current positions Pb, Pa of the straight-moving vehicle VB and the right-turning vehicle VA on the road map are identified (S712). The vehicle speed VSPa of the right-turning vehicle VA is read (S713), and it is determined whether the vehicle speed VSPa is higher than a second predetermined vehicle speed Vth2 (S714). If the vehicle speed is higher than the second predetermined vehicle speed Vth2, the collision prediction area ACP is maintained at the previously set size, whereas if the vehicle speed is equal to or lower than the second predetermined vehicle speed Vth2, the collision prediction area ACP is reduced (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 intersection arrival distance Db of the straight-moving vehicle VB is calculated (S718), and an alarm distance Dth2 corresponding to the vehicle speed VSPb of the straight-moving vehicle VB is calculated (S719, S720).If the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S721), an alarm is issued (S722).

[0164] (Explanation of action and effect) The vehicle notification system 1 according to this embodiment has the above-described configuration. The effects obtained by this embodiment will be described below.

[0165] First, in a situation where a right-turning vehicle VA is turning right at an intersection CS and a straight-moving vehicle VB is traveling straight toward the intersection CS in an oncoming lane L22, the current position Pa of the right-turning vehicle VA on a road map and the current position Pb of the straight-moving vehicle VB on the road map are identified. After detecting that the right-turning vehicle VA intends to turn right, and before the right-turning vehicle VA reaches the intersection CS, an intersection area ACS is set, and a first alert timing is set according to the relative position of the right-turning vehicle VA with respect to the intersection area ACS. After setting the first alert timing, a second alert timing is set according to the behavior of the right-turning vehicle VA in the intersection area ACS. The second alert timing is a timing when the right-turning vehicle VA is closer to the predicted collision point CPP than the first alert timing. Then, at each of the first and second alert timings, a predetermined alert mode is issued to traffic participants, including the right-turning vehicle VA and the straight-moving vehicle VB, provided that a predetermined alert condition is met with respect to the position Pb of the straight-moving vehicle VB.

[0166] In this way, while the right-turning vehicle VA is passing through the intersection CS, appropriate alarm timings (first and second alarm timings) are set according to the relative position of the right-turning vehicle VA with respect to the intersection area ACS and the behavior of the right-turning vehicle VA in the intersection area ACS, and at each of the set alarm timings, an alarm is issued in a predetermined mode, provided that predetermined alarm conditions are met.

[0167] For example, at the first alert timing, an information alert is issued to prompt the driver to recognize the presence of the other vehicle (e.g., a straight-moving vehicle VB in relation to a right-turning vehicle VA), and at the second alert timing, an alarm is issued to prompt the driver to recognize a higher level of urgency regarding a collision with the other vehicle.

[0168] This makes it possible to issue an alert in an appropriate mode at an appropriate time according to the urgency of the situation in a situation where there is a risk of a collision between a right-turning vehicle VA and a straight-moving vehicle VB.

[0169] In this embodiment, the intersection area ACS and the collision prediction area ACP are set before the right-turning vehicle VA reaches the intersection CS, and the areas ACS and ACP are set to a size that corresponds to the driving state of the right-turning vehicle VA before it reaches the intersection CS. This allows the intersection area ACS and the collision prediction area ACP to be set to an appropriate size that corresponds to the actual driving state of the right-turning vehicle VA, and makes it possible to optimize the timing of the first and second alerts, for example, by accelerating the timing of the first alert, thereby realizing more appropriate alerts.

[0170] Second, by detecting the vehicle speed VAPa of the right-turning vehicle VA as the driving condition and setting the intersection area ACS to a size corresponding to the vehicle speed VSPa of the right-turning vehicle VA, it becomes possible to more appropriately issue an alarm at each timing through further optimization of the first and second alarm timings.

[0171] Here, by expanding the intersection area ACS as the vehicle speed VSPa of the right-turning vehicle VA increases, it becomes possible to issue an alert earlier to the right-turning vehicle VA traveling toward the intersection CS at a relatively high vehicle speed VSPa. For example, in a situation where the right-turning vehicle VA is decelerating while entering the intersection CS, the expansion of the intersection area ASC will issue an alert earlier, ensuring that the driver of the right-turning vehicle VA has time to take necessary measures in response to the alert, such as paying attention to vehicles in the oncoming lanes L21 and L22.

[0172] The intersection area ACS is set to a size corresponding to the distance obtained by multiplying the first alert pre-activation time PRD22 by the vehicle speed VSPa of the right-turning vehicle VA, and the first alert pre-activation time PRD22 is calculated as the time it takes for the vehicle speed VSPb of the straight-moving vehicle VB to decrease from the vehicle speed at the time of detection to 0 at a relatively low first predetermined deceleration DEC1. This makes it possible to ensure that the drivers of not only the right-turning vehicle VA but also the straight-moving vehicle VB have enough time to take necessary measures in response to the activation of the alert.

[0173] Third, in addition to the intersection area ACS, the size of the collision prediction area ACP can also be changed depending on the driving conditions of the right-turning vehicle VA. This allows the first and second alert timings to be linked, making it possible to more appropriately switch from the first to the second alert timing. For example, if the first alert timing is advanced by expanding the intersection area ACS, the second alert timing can also be advanced by changing the collision prediction area ACP accordingly, ensuring that traffic participants have enough time to take the necessary measures in response to the alerts at each timing.

[0174] The collision prediction area ACP is also set to a width corresponding to the distance obtained by multiplying the vehicle speed VSPa of the right-turning vehicle VA by the alert pre-activation time (second alert pre-activation time PRD21), and the second alert pre-activation time PRD21 is calculated as the time it takes for the vehicle speed VSPb of the straight-moving vehicle VB to decrease from the vehicle speed at the time of detection to 0 at a second predetermined deceleration DEC2 that is higher than the first predetermined deceleration DEC1. This makes it possible to appropriately set the second alert activation timing without excessively widening the collision prediction area ACP.

[0175] Fourth, an alert is issued at the first alert timing (in the first predetermined mode) on the condition that the straight-moving vehicle VB is at a position that is a first predetermined distance Dth1 from the intersection CS or closer to the intersection CS, while an alert is issued at the second alert timing (in the second predetermined mode) on the condition that the straight-moving vehicle VB is at a position that is a second predetermined distance Dth2 from the intersection CS or closer to the intersection CS. This makes it possible to issue alerts in each mode at appropriate timings and to realize appropriate alerts according to the urgency of the situation.

[0176] (Other embodiments) The setting of the expanded judgment area, in other words, the expansion of the intersection area ACS and the collision prediction area ACP, may be performed on the condition that the right-turning vehicle VA and the straight-moving vehicle VB are facing each other with the intersection CS between them. Specifically, the setting of the expanded judgment area is avoided when it is expected that the straight-moving vehicle VB will pass the intersection CS before the right-turning vehicle VA enters the intersection CS, or that the right-turning vehicle VA will pass the intersection CS before the straight-moving vehicle VB approaches the intersection CS.

[0177] 18 shows a situation in which a straight-moving vehicle VB passes through an intersection CS before a right-turning vehicle VA enters the intersection CS. In this embodiment, when the intention of the right-turning vehicle VA to turn right is detected, if it is expected that the situation shown in the figure will occur, setting of an expanded determination area is essentially prohibited.

[0178] Specifically, the system compares the intersection entry time ta1, when the right-turning vehicle VA arrives at an intersection entry point Pa1 in the lane L11 it is traveling in, with the intersection exit time tb2, when the straight-moving vehicle VB arrives at an intersection exit point Pb2 in the lane L22 it is traveling in, and if the intersection entry time ta1 of the right-turning vehicle VA is later than the intersection exit time tb2 of the straight-moving vehicle VB, the system sets the intersection area ACS and collision prediction area ACP to their normal sizes, in other words, the sizes for normal alert issuance. The intersection entry point Pa1 of the right-turning vehicle VA and the intersection exit point Pb2 of the straight-moving vehicle VB can both be set on the outer edge of the intersection area ACS, and 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 the road map information, the current position Pb and vehicle speed VSPb of the straight-moving vehicle VB.

[0179] Simply put, the intersection entry time ta1 of the right-turning vehicle VA can be calculated using the following equation (6.1) where Da1 is the distance from the current position Pa to the intersection center CTR at the time the intention to turn right is detected (time t0) and φacs is the radius of the intersection area ACS, and the intersection exit time tb2 of the straight-moving vehicle VB can be calculated using the following equation (6.2) where Db1 is the distance from the current position Pb to the intersection center CTR at the time the intention of the right-turning vehicle VA to turn right is detected and φacs is the radius of the intersection area ACS. ta1=t0+(Da1-φacs) / VSPa …(6.1) tb2=t0+(Db1+φacs) / VSPb…(6.2)

[0180] 19 shows a situation in which a right-turning vehicle VA passes through the intersection CS before a straight-moving vehicle VB reaches the alert point. In this embodiment, in addition to the situation shown above, the setting of an expanded determination area is substantially prohibited even when the situation shown in the figure is expected to occur at the time when the intention of the right-turning vehicle VA to turn right is detected.

[0181] Specifically, the system compares the intersection passage time ta2, when the right-turning vehicle VA arrives at an exit point Pa2 from the intersection CS, with the alert position arrival time tb1, when the straight-moving vehicle VB arrives at a point Pb1 (hereinafter referred to as the "alert implementation point") a predetermined distance from the intersection CS. If the alert position arrival time tb1 is later than the intersection passage time ta2, the intersection area ACS and the collision prediction area ACP are set to their normal sizes. The intersection exit point Pa2 of the right-turning vehicle VA can be set on the outer edge of the intersection area ACS, and the alert implementation point Pb1 of the straight-moving vehicle VB can be set to a point that is an information presentation distance Dth1 from the intersection CS, for example, a point that is the 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 position arrival time tb1 can be calculated based on the road map information, the current position Pb and vehicle speed VSPb of the straight-moving vehicle VB.

[0182] Simply put, the time ta2 at which the right-turning vehicle VA passes through the intersection can be calculated using the following equation (7.1) where Da1 is the distance from the current position Pa to the intersection center CTR at the time the intention to turn right is detected (time t0) and φacs is the radius of the intersection area ACS, and the time tb1 at which the straight-moving vehicle VB reaches the alert position can be calculated using the following equation (7.2) where Db2 is the distance from the current position Pb to the collision prediction area ACP at the time the intention of the right-turning vehicle VA to turn right is detected and Dth1 is the information presentation distance. ta2=t0+(Da1+φacs) / VSPa …(7.1) tb1=t0+(Db2-Dth1) / VSPb …(7.2)

[0183] 17 is a flowchart showing the overall flow of notification control according to this embodiment. In this embodiment, notification control can be realized as control that performs the steps shown in S811 to S815 in addition to the steps shown in the flowchart of FIG.

[0184] When the process is performed by the controller 101a of the right-turning vehicle VA, the differences from the flowchart in Figure 4 will be explained mainly. After detecting a straight-moving vehicle VB in the oncoming lane L22 (S112), if it is detected that the right-turning vehicle VA, the subject vehicle, has an intention to turn right (S113), then in S811, the time ta1 at which the right-turning vehicle VA enters the intersection and the time ta2 at which the right-turning vehicle VA passes through the intersection are calculated.

[0185] In S812, the time tb1 when the vehicle VB travels straight ahead reaches the reporting position and the time tb2 when the vehicle VB leaves the intersection are calculated.

[0186] In S813, it is determined whether the intersection entry time ta1 of the right-turning vehicle VA is later than the intersection exit time tb2 of the straight-moving vehicle VB. If the intersection entry time ta1 is later than the intersection exit time tb2, proceed to S815, and if it is earlier than the intersection exit time tb2, proceed to S814.

[0187] In S814, it is determined whether the arrival time tb1 of the straight-moving vehicle VB at the reporting position is later than the intersection passage time ta2 of the right-turning vehicle VA. If the arrival time tb1 at the reporting position is later than the intersection passage time ta2, the process proceeds to S815, and if it is earlier than the intersection passage time ta2, the process executes the steps S114 to S119 enclosed by the two-dot chain line frame A in FIG. 4.

[0188] In S815, normal alarm processing is performed, which effectively prohibits the setting of an expanded determination area.

[0189] In this way, setting an extended judgment area increases the computational load on the controllers 101a and 101b required to monitor right-turning vehicles VA and straight-moving vehicles VB (such as tracking current positions Pa and Pb). However, by avoiding or prohibiting the setting of an extended judgment area and setting the intersection area ACS to its normal size, which in this embodiment is set to the smallest size possible, it is possible to suppress the implementation of unnecessary control related to alarm issuance and the resulting increase in computational load, and to allocate the extra capacity to other controls, thereby making effective use of the computational capacity of the controllers 101a and 101b.

[0190] In this embodiment, the setting of an extended judgment area is prohibited when it is expected that a straight-moving vehicle VB will pass the intersection CS before a right-turning vehicle VA enters the intersection CS, or that a right-turning vehicle VA will pass the intersection CS before the straight-moving vehicle VB approaches the intersection CS. However, in similar situations, it is also possible to configure the system so that the implementation of notification control itself is avoided or prohibited.

[0191] In the above description, the intersection area ACS and the collision prediction area ACP are expanded by changing the width or radius φacs, φacp of these areas ACS and ACP, in other words, by switching between multiple areas ACS and ACP of different widths. However, changing the width of the determination area ACS and ACP or setting an expanded determination area can also be done by superimposing an expanded area on the area ACS and ACP of a base or normal width. For example, in S116 of the flowchart in FIG. 4, if the vehicle speed VSPa of the right-turning vehicle VA is higher than a predetermined vehicle speed, the expanded determination area is set by superimposing an expanded area on the area of ​​normal width. If the vehicle speed is equal to or lower than the predetermined vehicle speed, the area of ​​normal width is set as the determination area. The expanded area can be formed in any suitable shape, such as a circle, a sector, or the like. If the expanded area is circular or sector-shaped, its center can be set at the intersection center CTR.

[0192] Furthermore, the distance Db from the intersection CS to the straight-moving vehicle VB is the distance from the outer edge of the collision prediction area ACP, specifically, the intersection of the travel path TRb of the straight-moving vehicle VB and the circle defining the outer edge of the collision prediction area ACP (the circle shown by the dashed line in the figure) to the straight-moving vehicle VB. However, the distance Db may be the distance from the collision prediction point CPP to the straight-moving vehicle VB, or the distance along the center line of the oncoming lane L22 from the right-turning vehicle VA to the straight-moving vehicle VB.

[0193] The calculation unit of the notification system 1 is composed of the controllers 101a and 101b provided in the right-turning vehicle VA or the straight-moving vehicle VB, respectively, and the controllers 101a and 101b constitute a single virtual controller. However, it is also possible to configure the notification control to be performed outside the vehicle by storing a road map and a computer program for notification control in a roadside device or a remote server. In this case, the right-turning vehicle VA and the straight-moving vehicle VB transmit their respective position information to an external controller via road-to-vehicle communication and receive a command signal that is the result of a calculation related to control. Then, based on the command signal, the controller presents information or issues an alarm. [Explanation of symbols]

[0194] 1...vehicle notification system, 101a, 101b...controller, 111a, 111b...position sensor, 112a, 112b...vehicle speed sensor, 113a, 113b...right turn signal switch, 121a, 121b...transmitter, 122a, 122b...receiver, 131a, 131b...HMI device.

Claims

1. A vehicle turning right in the lane leading to the intersection, A vehicle notification system that issues a warning to traffic participants including a straight-moving vehicle traveling in a straight direction toward the intersection in an oncoming lane relative to the lane in which the right-turning vehicle is present, road map storage means for storing a road map including the intersection; a right-turning vehicle position specifying means for specifying a current position of the right-turning vehicle on the road map; a straight-moving vehicle position specifying means for specifying a current position of the straight-moving vehicle on the road map; a right-turn intention detection means for detecting an intention of the right-turning vehicle to turn right; a driving state detection means for detecting a driving state of the right-turning vehicle; an intersection area setting means for setting, in association with the road map, an intersection area that overlaps with a route that the right-turning vehicle will travel when passing through the intersection after detecting the right-turn intention and before the right-turning vehicle reaches the intersection; a first alert timing setting means for setting a first alert timing according to the relative position of the right-turning vehicle with respect to the intersection area set by the intersection area setting means, based on the current position of the right-turning vehicle identified by the right-turning vehicle position identifying means; a second alert timing setting means for setting a second alert timing according to a behavior of the right-turning vehicle in the intersection area after the first alert timing setting means sets the first alert timing; an alert issuing means for issuing an alert in a predetermined mode to the traffic participants on the condition that an alert condition determined with respect to the position of the straight-moving vehicle is satisfied at each of the first alert timing set by the first alert timing setting means and the second alert timing set by the second alert timing setting means, The intersection area setting means sets the intersection area to a size according to the driving state of the right-turning vehicle detected by the driving state detection means before the vehicle reaches the intersection.

2. 2. The vehicle notification system according to claim 1, wherein the driving condition detection means detects a vehicle speed of the right-turning vehicle as the driving condition of the right-turning vehicle.

3. 3. The vehicle notification system according to claim 2, wherein the intersection area setting means expands the intersection area as the vehicle speed of the right-turning vehicle detected by the driving state detection means increases.

4. further comprising a vehicle speed detection means for detecting the vehicle speed of the straight-moving vehicle, The intersection area setting means calculating a first warning pre-issue time period required for the vehicle speed of the straight-moving vehicle to decrease to zero at a first predetermined deceleration from the vehicle speed detected by the vehicle speed detection means; The vehicle notification system according to claim 3 , wherein the intersection area is set to a size corresponding to a distance obtained by multiplying the first warning advance time by a vehicle speed of the right-turning vehicle.

5. a collision prediction area setting means for setting, in association with the road map, a collision prediction area that includes a point where a route taken by the right-turning vehicle when passing through the intersection and a route taken by the straight-moving vehicle when passing through the intersection intersect, the collision prediction area being different from the intersection area and including the collision prediction point; 4. The vehicle warning system according to claim 1, wherein the second alert timing setting means sets the second alert timing to a timing when, after setting the first alert timing, the right-turning vehicle is traveling toward the predicted collision point or when the right-turning vehicle is present within the predicted collision area.

6. further comprising a vehicle speed detection means for detecting the vehicle speed of the straight-moving vehicle, The intersection area setting means calculating a first warning pre-issue time period required for the vehicle speed of the straight-moving vehicle to decrease to zero at a first predetermined deceleration from the vehicle speed detected by the vehicle speed detection means; The intersection area is set to a size corresponding to a distance obtained by multiplying the first warning advance time by the vehicle speed of the right-turning vehicle, The collision prediction area setting means calculating a second warning pre-time period required for the vehicle speed of the straight-moving vehicle to decrease from the vehicle speed detected by the vehicle speed detection means to zero at a second predetermined deceleration that is higher than the first predetermined deceleration; The vehicle warning system according to claim 5 , wherein the collision prediction area is set to a size corresponding to a distance obtained by multiplying the second warning advance time by a vehicle speed of the right-turning vehicle.

7. a collision prediction area setting means for setting, in association with the road map, a collision prediction area that includes a point where a route taken by the right-turning vehicle when passing through the intersection and a route taken by the straight-moving vehicle when passing through the intersection intersect, the collision prediction area being different from the intersection area and including the collision prediction point; the second alert timing setting means sets, after setting the first alert timing, a timing when the right-turning vehicle is traveling toward the predicted collision point or when the right-turning vehicle is present in the predicted collision area as the second alert timing; The vehicle warning system according to claim 1 , wherein the collision prediction area setting means changes the size of the collision prediction area in accordance with the size of the intersection area.

8. The alarm issuing means issuing an alert in a first predetermined mode on the condition that the straight-moving vehicle is located at a first predetermined distance from the intersection or at a position closer to the intersection at the first alert timing; 5. A vehicle warning system as described in any one of claims 1 to 4, wherein, at the second warning timing, a second predetermined mode different from the first predetermined mode is issued, provided that the straight-moving vehicle is located at a second predetermined distance from the intersection that is shorter than the first predetermined distance or is located at a position closer to the intersection than the second predetermined distance.

9. 5. A vehicle warning system as described in any one of claims 1 to 4, wherein the intersection area setting means compares an intersection entry time at which the right-turning vehicle arrives at an intersection entry point in the lane in which it is traveling with an intersection exit time at which the straight-moving vehicle arrives at an intersection exit point in the lane in which it is traveling, and sets the intersection area to a predetermined minimum size if the intersection entry time is later than the intersection exit time.

10. the alert issuing means issues an alert in the predetermined mode on the condition that the straight-moving vehicle is at a predetermined alert distance from the intersection or is closer to the intersection at each of the first alert issuing timing and the second alert issuing timing, 5. A vehicle warning system as described in any one of claims 1 to 4, wherein the intersection area setting means compares an intersection passing time when the right-turning vehicle arrives at an exit point from the intersection with an alert position arrival time when the straight-moving vehicle arrives at a point that is the alert distance from the intersection, and sets the intersection area to a predetermined minimum size if the alert position arrival time is later than the intersection passing time.

11. A vehicle turning right in the driving lane leading to the intersection, A vehicle notification system that issues a warning to traffic participants including a straight-moving vehicle traveling in a straight direction toward the intersection in an oncoming lane relative to the driving lane, road map storage means for storing a road map including the intersection; a right-turning vehicle position specifying means for specifying a current position of the right-turning vehicle on the road map; a straight-moving vehicle position specifying means for specifying a current position of the straight-moving vehicle on the road map; a right-turn intention detection means for detecting an intention of the right-turning vehicle to turn right; an intersection area setting means for setting, in association with the road map, an intersection area that overlaps with a route that the right-turning vehicle will travel when passing through the intersection after detecting the right-turn intention and before the right-turning vehicle reaches the intersection; a collision prediction area setting means for setting, in association with the road map, a collision prediction area that includes a point where a route taken by the right-turning vehicle when passing through the intersection and a route taken by the straight-moving vehicle when passing through the intersection intersect, the collision prediction area being different from the intersection area and including the collision prediction point; a first alert timing setting means for setting a first alert timing when the right-turning vehicle is present in the intersection area; a second alert timing setting means for setting a second alert timing when the right-turning vehicle is present in the collision prediction area; an alert issuing means for issuing an alert in a predetermined mode to the traffic participants on the condition that an alert condition determined with respect to the position of the straight-moving vehicle is satisfied at each of the first alert timing set by the first alert timing setting means and the second alert timing set by the second alert timing setting means, The intersection area setting means sets the intersection area to a size according to the driving state of the right-turning vehicle detected by the driving state detection means before the vehicle reaches the intersection.

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