Vehicle notification system

Abstract

In a traffic situation where the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC are traveling toward the intersection CS, the vehicle notification system 1 issues a notification to the traffic participants VA, VB and VC under a condition that a notification issuance condition defined in relation to the positions of the oncoming vehicle VB and the crossing vehicle VC is met at the notification issuance timing in accordance with the relative position of the right turning vehicle VA to the intersection CS after detecting the right turn intention of the right turning vehicle VA. When the notification issuance condition is met for both the oncoming vehicle VB and the crossing vehicle VC, the vehicle notification system 1 issues a notification to each of them to raise awareness of the presence of the other.

Description

BACKGROUND OF THE INVENTIONField of the Invention

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

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

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

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

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

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

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

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

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

[0010] In this aspect, the vehicle notification system may include a direction-change-intention detection unit that detects a direction change intention of the first vehicle while turning right or left at the intersection, a notification issuance timing setting unit that sets a notification issuance timing in accordance with a relative positional relationship between the first vehicle and the intersection after the direction-change-intention detection unit detects the direction change intention, a first notification issuing unit that performs first notification issuance for at least one of the first vehicle or the second vehicle under a condition that a first predetermined notification issuance condition defined in relation to a position of the second vehicle is met at the notification issuance timing set by the notification issuance timing setting unit, a second notification issuing unit that performs second notification issuance for at least one of the first vehicle or the third vehicle under a condition that a second predetermined notification issuance condition defined in relation to a position of the third vehicle is met at the notification issuance timing, and a third notification issuing unit that performs third notification issuance to promote at least one of the second vehicle or the third vehicle to recognize presence of the other one of the second vehicle or the third vehicle in a case where both the first and second predetermined notification issuance conditions are met at the notification issuance timing.

[0011] The vehicle notification system may further include a determination area setting unit that sets an intersection area that overlaps on a path where the first vehicle travels when the first vehicle passes the intersection.

[0012] In this case, the notification issuance timing setting unit may be configured to set, as the notification issuance timing, a timing at which or after the first vehicle arrives at the intersection area.

[0013] Regarding a point at which the path where the first vehicle travels when the first vehicle passes the intersection and a path where the second vehicle travels when the second vehicle passes the intersection intersect as a first predicted collision point, the determination area setting unit may be configured to set a first predicted collision area that includes the first predicted collision point in addition to the intersection area.

[0014] In this case, the notification issuance timing setting unit may be configured to set, as the notification issuance timing, a first notification issuance timing and, in a case where the first vehicle is traveling at a higher vehicle speed than a predetermined vehicle speed toward the first predicted collision point outside the first predicted collision area or is located inside the first predicted collision area after the first notification issuance timing is set, a second notification issuance timing.

[0015] The first notification issuing unit may be configured to perform the first notification issuance under the condition that the first predetermined notification issuance condition is met at each of the first and second notification issuance timings and differentiate modes for the first notification issuance for the first notification issuance timing and the second notification issuance timing.

[0016] The third notification issuing unit may be configured to differentiate modes for the third notification issuance between a case where the first notification issuing unit performs the first notification issuance at the first notification issuance timing and a case where the first notification issuing unit performs the first notification issuance at the second notification issuance timing.

[0017] Regarding a point at which the path where the first vehicle travels when the first vehicle passes the intersection and a path where the third vehicle travels when the third vehicle passes the intersection intersect as a second predicted collision point, the determination area setting unit may be configured to set a second predicted collision area that includes the second predicted collision point in addition to the intersection area.

[0018] In this case, the notification issuance timing setting unit may be configured to set, as the notification issuance timing, a first notification issuance timing and, in a case where the third vehicle is traveling at a higher vehicle speed than a predetermined vehicle speed toward the second predicted collision point outside the second predicted collision area or is located inside the second predicted collision area after the first notification issuance timing is set, a second notification issuance timing.

[0019] The second notification issuing unit may be configured to perform the second notification issuance under a condition that the second predetermined notification issuance condition is met at each of the first and second notification issuance timings and differentiate modes for the second notification issuance for the first notification issuance timing and the second notification issuance timing.

[0020] The third notification issuing unit may be configured to differentiate modes for the third notification issuance between a case where the second notification issuing unit performs the second notification issuance at the first notification issuance timing and a case where the second notification issuing unit performs the second notification issuance at the second notification issuance timing.

[0021] In another aspect of the present invention, a vehicle notification system is configured to perform notification issuance for traffic participants including a first vehicle that is present in a first lane leading to an intersection, an second vehicle that travels toward the intersection in a second lane opposite to the first lane and a third vehicle that travels toward the intersection in a third lane intersecting the first lane.

[0022] In this aspect, the vehicle notification system may include a direction-change-intention detection unit that detects a direction change intention of the first vehicle while turning right or left at the intersection, a notification issuance timing setting unit that sets a notification issuance timing in accordance with a relative positional relationship between the first vehicle and the intersection after the direction-change-intention detection unit detects the direction change intention, a first notification issuing unit that performs first notification issuance for at least one of the first vehicle or the second vehicle under a condition that a first predetermined notification issuance condition defined in relation to a position of the second vehicle is met at the notification issuance timing set by the notification issuance timing setting section, a crossing vehicle detection unit that detects presence of the third vehicle in the third lane, and a third notification issuing unit that performs third notification issuance to promote at least one of the second vehicle or the third vehicle to recognize presence of the other one of the second vehicle or the third vehicle in a case where the crossing vehicle detection unit detects the third vehicle during execution of the first notification issuance by the first notification issuing unit.

[0023] Regarding a point where a path where the first vehicle travels when the first vehicle passes the intersection and a path where the second vehicle travels when the second vehicle passes the intersection intersect as a first predicted collision point, the notification issuance timing setting unit may be configured to set, as the notification issuance timing, a first notification issuance timing and a second notification issuance timing at which the first vehicle is located at a position closer to the first predicted collision point than at the first notification issuance timing, after the first notification issuance timing is set.

[0024] In this case, the first notification issuing unit may be configured to perform the first notification issuance in different modes at each of the first and second notification issuance timings under a condition that the first predetermined notification issuance condition is met.

[0025] The third notification issuing unit may be configured to differentiate modes for the third notification issuance between a case where the first notification issuing unit performs the first notification issuance at the first notification issuance timing and a case where the first notification issuing unit performs the first notification issuance at the second notification issuance timing.

[0026] In a further aspect of the present invention, a vehicle notification system is configured to perform notification issuance for traffic participants including a first vehicle that is present in a first lane leading to an intersection, an second vehicle that travels toward the intersection in a second lane opposite to the first lane, and a third vehicle that travels toward the intersection in a third lane intersecting the first lane.

[0027] In this aspect, the vehicle notification system may include a direction-change-intention detection unit that detects a direction change intention of the first vehicle while turning right or left at the intersection, a notification issuance timing setting unit that sets a notification issuance timing in accordance with a relative positional relationship between the first vehicle and the intersection after the direction-change-intention detection unit detects the direction change intention, a second notification issuing unit that performs second notification issuance for at least one of the first vehicle or the third vehicle under a condition that a second predetermined notification issuance condition defined in relation to a position of the third vehicle is met at the notification issuance timing set by the notification issuance timing setting unit, an oncoming vehicle detection unit that detects presence of the second vehicle in the second lane, and a third notification issuing unit that performs third notification issuance to promote at least one of the third vehicle or the second vehicle to recognize presence of the other one of the third vehicle or the second vehicle in a case where the oncoming vehicle detection unit detects the second vehicle during execution of the second notification issuance by the second notification issuing unit.

[0028] Regarding a point at which a path where the first vehicle travels when the first vehicle passes the intersection and a path where the third vehicle travels when the third vehicle passes the intersection intersect as a second predicted collision point, the notification issuance timing setting unit may be configured to set, as the notification issuance timing, a first notification issuance timing and a second notification issuance timing at which the first vehicle is located at a position closer to the second predicted collision point than at the first notification issuance timing, after the first notification issuance timing is set.

[0029] In this case, the second notification issuing unit may be configured to perform the second notification issuance in different modes at each of the first and second notification issuance timings under a condition that the second predetermined notification issuance condition is met.

[0030] The third notification issuing unit may be configured to differentiate modes for the third notification issuance for a case where the second notification issuing unit performs the second notification issuance at the first notification issuance timing and a case where the second notification issuing unit performs the second notification issuance at the second notification issuance timing.

[0031] The intersection may be an intersection with no traffic lights for regulating passage of the third vehicle.

[0032] According to an embodiment of the present invention, in a situation where a first vehicle, an second vehicle and a third vehicle are traveling toward an intersection, first or second notification issuance is performed under a condition that a notification issuance condition defined in relation to the positions of the second vehicle and the third vehicle is met at a notification issuance timing in accordance with a relative positional relationship between the first vehicle and the intersection after a direction change intention of the first vehicle is detected. This allows for appropriate notification issuance in accordance with a degree of urgency of circumstances in regard to collision between the first vehicle and the second vehicle or collision between the first vehicle and the third vehicle. Here, it is possible to reduce circumstances where the second vehicle and the third vehicle come into contact with each other or collide against each other and to promote smooth and safe passage of the traffic participants by performing third notification issuance to promote at least one of the second vehicle or the third vehicle to recognize presence of the other one of the second vehicle or the third vehicle in a case where both the first and second predetermined notification issuance conditions are met.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Fig. 1 is a schematic diagram illustrating an overall configuration of a vehicle notification system according to an embodiment of the present embodiment; Fig. 2 is a schematic diagram illustrating an internal configuration of a controller included in a right turning vehicle; Fig. 3 is a schematic diagram illustrating an internal configuration of a controller included in an oncoming vehicle; Fig. 4 is a schematic diagram illustrating an internal configuration of a controller included in a crossing vehicle; Fig. 5 is a flowchart illustrating an overall flow of notification control executed by the right turning vehicle; Fig. 6 is a flowchart illustrating content of the notification control (information presentation processing) executed by the right turning vehicle; Fig. 7 is a flowchart illustrating content of the notification control (alarm processing) executed by the right turning vehicle; Fig. 8 is a flowchart illustrating content of the processing executed in section A in Fig. 5. Fig. 9 is a flowchart illustrating an overall flow of notification control executed by the oncoming vehicle and the crossing vehicle; Fig. 10 is a flowchart illustrating content of the notification control (information presentation processing) executed by the oncoming vehicle and the crossing vehicle; Fig. 11 is a flowchart illustrating content of the notification control (alarm processing) executed by the oncoming vehicle and the crossing vehicle; Fig. 12 is a flowchart illustrating content of the processing executed in a section B in Fig. 9. Fig. 13 is an explanatory diagram illustrating a method of calculating an information presentation distance and an alarm distance; Fig. 14 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a target of a notification; Fig. 15 is a schematic diagram illustrating a relationship between the right turning vehicle and the oncoming vehicle at an issuance timing of information presentation; Fig. 16 is a schematic diagram illustrating a relationship between the right turning vehicle and the oncoming vehicle at an issuance timing of an alarm; Fig. 17 is a schematic diagram illustrating a relationship between the right turning vehicle and the crossing vehicle at an issuance timing of information presentation; Fig. 18 is a schematic diagram illustrating a relationship between the right turning vehicle and the crossing vehicle at an issuance timing of an alarm; and Fig. 19 is a schematic diagram illustrating a situation after the oncoming vehicle and the crossing passes an intersection. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Hereinafter, embodiments of the present invention will be described with reference to the drawings.(Overall Configuration of Vehicle Notification System)

[0035] Fig. 1 is a schematic diagram illustrating a configuration of a vehicle notification system (hereinafter, simply referred to as a "notification system" in some cases) 1 according to an embodiment of the present invention.

[0036] In the present embodiment, a traffic situation where a vehicle (hereinafter, referred to as a "right turning vehicle") VA traveling toward an intersection on a left-hand traffic road, another vehicle (hereinafter, referred to as an "oncoming vehicle") VB traveling in a straight direction toward the intersection in a lane (hereinafter, referred to as an "opposite lane") opposite to a lane (hereinafter, referred to as a "right turning lane") in which the right turning vehicle VA is traveling and a further vehicle (hereinafter, referred to as a "crossing vehicle") VC traveling in a straight direction toward the intersection in a lane (which is a lane that intersects the right turning lane, hereinafter, referred to as a "crossing lane") that joins the intersection from a side of the right turning vehicle are present is assumed. The crossing lane is not limited to a lane that connects from the left side of the right turning vehicle, but it may also be a lane that connects from the right side. The notification system 1 can be applied not only to left-hand traffic roads but also to right-hand traffic roads. In a case of right-hand traffic, a traffic situation where a left turning vehicle traveling toward an intersection, an oncoming vehicle traveling toward the intersection in an opposite lane and a crossing vehicle traveling toward the intersection in a crossing lane are present is a target. In other words, the notification system 1 can be applied to traffic situations where a right or left turning vehicle (hereinafter, referred to as a "right or left turning vehicle" or a "non-straight traveling vehicle"), an oncoming vehicle and a crossing vehicle are present in the respective one of the three lanes leading into the intersection. In a case of left-hand traffic, the right turning vehicle is a vehicle turning right at the intersection and should not hinder the passage of the oncoming vehicle traveling straight through the intersection.

[0037] The notification system 1 includes, as main elements related to the present embodiment, auxiliary devices such as vehicle sensors 111 to 113, a communication device 121, a human machine interface (HMI) device 131 and an alarm 132 in addition to a controller 101.

[0038] In the present embodiment, various elements including the controller 101 are provided in each of the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC. A controller 101a included in the right turning vehicle VA, a controller 101b included in the oncoming vehicle VB and a controller 101b included in the crossing vehicle VC configure one virtual controller constituting the notification system 1 through mutual cooperation. It is a matter of course that the notification system 1 can be configured as an in-vehicle system for the right turning vehicle VA by the controller 101a included in the right turning vehicle VA and the auxiliary devices thereof, can also be configured as an in-vehicle system for the oncoming vehicle VB by the controller 101b included in the oncoming vehicle VB and the auxiliary devices thereof and can also be configured as an in-vehicle system for the crossing vehicle VC by the controller 101c included in the crossing vehicle VC and the auxiliary devices thereof.

[0039] In the following description, vehicle-to-vehicle communication is performed between the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC to allow respective vehicle information related to the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC to be shared among all the vehicles VA, VB and VC. In the present embodiment, the vehicle information to be communicated or shared among the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC includes current positions Pa, Pb and Pc, vehicle speeds VSPa, VSPb and VSPc, operating statuses of right turn signals (that is, outputs of right turn signal switches) and lane IDs of each of the vehicles VA, VB and VC. The communication among the vehicles VA, VB and VC is not limited to direct communication via vehicle-to-vehicle communication and may also be performed indirectly through roadside equipment installed at roadsides, servers disposed remotely, communication devices included in vehicles other than the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC. Communication between the right turning vehicle VA and the oncoming vehicle VB can be mediated by the crossing vehicle VC, and likewise, communication between the right turning vehicle VA and the crossing vehicle VC can be mediated by the oncoming vehicle VB.

[0040] In the present embodiment, the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC constitute the notification system 1 with similar basic configurations. The right turning vehicle VA includes the controller 101a and also includes vehicle sensors 111a, 112a and 113a, a communication device 121a, an HMI device 131a and an alarm 132a. The oncoming vehicle VB includes the controller 101b and also includes vehicle sensors 111b, 112b and 113b, a communication device 121b, an HMI device 131b and an alarm 132b. The crossing vehicle VC includes the controller 101c and also includes vehicle sensors 111c, 112c and 113c, a communication device 121c, an HMI device 131c and an alarm 132c.

[0041] The controllers 101a, 101b and 101c constitute a calculation unit of the notification system 1 and generate and output a command signal in accordance with results of calculation. The controllers 101a, 101b and 101c are configured of microcomputers including central processing units (CPUs), storage devices such as ROMs and RAMs, and input / output interfaces.

[0042] The vehicle sensors 111a to 113a, 111b to 113b and 111c to 113c constitute a detection unit of the notification system 1. The right turning vehicle VA includes a position sensor 111a, a vehicle speed sensor 112a and a right turn signal switch 113a as the accompanying vehicle sensors, while the oncoming vehicle VB includes a position sensor 111b, a vehicle speed sensor 112b and a right turn signal switch 113b as the accompanying vehicle sensors and the crossing vehicle VC includes a position sensor 111c, a vehicle speed sensor 112c and a right turn signal switch 113c as the accompanying vehicle sensors.

[0043] 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 oncoming vehicle VB and the position sensor 111c detects the current position Pc of the crossing vehicle VC. The position sensors 111a, 111b and 111c can be configured of high-precision satellite positioning system (GNSS) receivers and detect the current positions of the target vehicles VA, VB and VC with latitude and longitude coordinates Pa (Pai, Paj), Pb (Pbi, Pbj) and Pc (Pci, Pcj).

[0044] The vehicle speed sensor 112a detects the traveling speed (hereinafter, referred to as a "vehicle speed") VSPa of the right turning vehicle VA, while the vehicle speed sensor 112b detects the vehicle speed VSPb of the oncoming vehicle VB and the vehicle speed sensor 112c detects the vehicle speed VSPc of the crossing vehicle VC. The vehicle speed sensors 112a, 112b and 112c can perform the detection by detecting wheel speeds (for example, rotation speeds of driven wheels) of the target vehicles VA, VB and VC and converting the wheel speeds into traveling distances per unit time using tire dynamic radii or the like.

[0045] The right turn signal switch 113a outputs an on signal when a right direction indicator (hereinafter, referred to as a "right turn signal") included in the right turning vehicle VA is activated, the right turn signal switch 113b outputs an on signal when the right turn signal included in the oncoming vehicle VB is activated and the right turn signal switch 113c outputs an on signal when the right turn signal included in the crossing vehicle VC is activated. The operations of the right turn signal switches 113a, 113b and 113c indicate that the target vehicles VA, VB and VC intend to turn right on the road or change lanes.

[0046] Detection signals from the position sensor 111a, the vehicle speed sensor 112a and the right turn signal switch 113a are output to the controller 101a, while detection signals from the position sensor 111b, the vehicle speed sensor 112b and the right turn signal switch 113b are output to the controller 101b and detection signals from the position sensor 111c, the vehicle speed sensor 112c and the right turn signal switch 113c are output to the controller 101c.

[0047] The HMI devices 131a, 131b and 131c constitute an output unit of the notification system 1. The HMI device 131a receives a command signal from the controller 101a and provides a notification related to a traffic situation to a driver of the right turning vehicle VA. The HMI device 131b receives a command signal from the controller 101b and provides a notification related to the traffic situation to a driver of the oncoming vehicle VB. The HMI device 131c receives a command signal from the controller 101c and provides a notification related to the traffic situation to a driver of the crossing vehicle VC.

[0048] The notifications may be provided by the HMI devices 131a, 131b and 131c visually or auditorily. The HMI devices 131a, 131b and 131c can provide both display and sound notifications and can also provide notifications using one of them. The HMI devices 131a, 131b and 131c are disposed at locations that allow the drivers to easily view the HMI devices 131a, 131b and 131c, such as on dashboards in the vehicles.

[0049] The alarm devices 132a, 132b and 132c constitute the output unit of the notification system 1 along with the HMI devices 131a, 131b and 131c. The alarm devices 132a, 132b and 132c receive command signals from the controllers 101a, 101b and 101c and perform notification issuance to promote the drivers of the vehicles VA, VB and VC to pay attention to vehicles entering the intersection. The alarm devices 132a, 132b and 132c can be installed not only as special elements for alerting the vehicles entering the intersection separately from the HMI devices 131a, 131b and 131c but can also be incorporated into the HMI devices 131a, 131b and 131c included in the vehicle VA, VB and VC.

[0050] In addition to the above, the right turning vehicle VA includes a communication device 121a, while the oncoming vehicle VB includes a communication device 121b and the crossing vehicle VC includes a communication device 121c. The communication devices 121a, 121b and 121c are provided with a transmitter and a receiver respectively, and the communication device 121a included in the right turning vehicle VA constitute a vehicle-to-vehicle communication device of the right turning vehicle VA, while the communication device 121b included in the oncoming vehicle VB constitute a vehicle-to-vehicle communication device of the oncoming vehicle VB and the communication device 121c included in the crossing vehicle VC constitute a vehicle-to-vehicle communication device of the crossing vehicle VC. The right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC can perform wireless communication via the mutual vehicle-to-vehicle communication devices.

[0051] As mentioned earlier, the communication among the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC is not limited to direct intercommunication among these vehicle VA, VB and VC but may also be indirect communication via roadside equipment, remote servers, other vehicles, or the like.

[0052] Fig. 14 is a schematic diagram schematically illustrating an example of a traffic situation assumed as a target of notification according to the present embodiment.

[0053] In the present embodiment, a traffic situation where the right turning vehicle VA, the oncoming vehicle VB, and the crossing vehicle VC are present and these vehicles VA, VB and VC are traveling toward an intersection CS is assumed. The intersection (a cross intersection in the present embodiment) CS is present on a road R with two lanes on each side including right turning lanes L11 and L21 and straight traveling lanes L12 and L22. In addition to the right turning lanes L11 and L21 and the straight traveling lanes L12 and L22, there may be a crossing lane L31 leading to the intersection CS, and the crossing lane L31 may be a road with one lane on each side or may be a road with two lanes on each side. The right turning vehicle VA is present in the right turning lane L11 on one side and is approaching the intersection CS, while the oncoming vehicle VB is present in the straight traveling lane L22 on the other side and is traveling in a straight traveling direction toward the intersection CS at a position separated from the intersection CS. The crossing vehicle VC is present in the crossing lane L31 and is traveling in the straight traveling direction toward the intersection CS at a position separated from the intersection CS. Here, the right turning lane L11 corresponds to the "first lane", the straight traveling lane L22 corresponds to the "second lane", and the crossing lane L31 corresponds to the "third lane". The right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC are included in the "traffic participants" that are targets of notification by the notification system 1. The right turning lane L21 and the straight traveling lane L22 opposite to the right turning lane L11 may be referred to as an "opposite right turning lane" and an "opposite straight traveling lane" below.

[0054] At the intersection CS, there are no traffic lights for regulating passage of vehicles (including the crossing vehicle VC) entering the intersection CS from the crossing lane L31, and only traffic lights (not illustrated) for regulating passage of vehicles entering the intersection CS from the right turning lane L11, the straight traveling lane L12, the opposite right turning lane L21 and the opposite straight traveling lane L22 are present. Therefore, in the illustrated situation, there is a concern that a timing of the right turning vehicle VA and the oncoming vehicle VB entering the intersection CS may coincide with a timing of the crossing vehicle VC entering the intersection CS.

[0055] A vehicle (hereinafter, referred to as a "waiting vehicle") VD stopping to wait for a right turn is present in the opposite right turning lane L21 before a stop line SL2 in front of the oncoming vehicle VB. In the illustrated situation, the waiting vehicle VD is a visual obstacle blocking a part of a view from the right turning vehicle VA and blocking a part of a view from the oncoming vehicle VB. In this situation, it is difficult to visually recognize the oncoming vehicle VB from the right turning vehicle VA due to the oncoming vehicle VB being present at a blind angle of the waiting vehicle VD seen from the right turning vehicle VA, and it is difficult to visually recognize the right turning vehicle VA from the oncoming vehicle VB due to the right turning vehicle VA being present at a blind angle of the waiting vehicle VD seen from the oncoming vehicle VB.

[0056] In such a situation, the notification system 1 monitors the relative positional relationship between the right turning vehicle VA and the oncoming vehicle VB after the right turning vehicle VA indicates its intention to turn right at the intersection CS by operating a right turn signal or the like. Then, the notification system 1 performs notification issuance in accordance with a degree of urgency of circumstances in regard to contact or collision between the right turning vehicle VA and the oncoming vehicle VB at an appropriate timing after the right turning vehicle VA approaches the intersection CS and before the right turning vehicle VA passes the intersection CS. The notification issuance performed between the right turning vehicle VA and the oncoming vehicle VB corresponds to the "first notification issuance".

[0057] In addition, the notification system 1 monitors the relative positional relationship between the right turning vehicle VA and the crossing vehicle VC following the same procedure after the indication of the right turn intention through an operation of the right turn signal or the like and performs notification issuance in accordance with the degree of urgency of circumstances in regard to contact or collision between the right turning vehicle VA and the crossing vehicle VC at an appropriate timing after the right turning vehicle VA approaches the intersection CS. The notification issuance performed between the right turning vehicle VA and the crossing vehicle VC corresponds to the "second notification issuance".

[0058] Furthermore, in a case where the notification system 1 simultaneously performs the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC (simultaneously performing both the notification issuance processes will be referred to as "simultaneous notification issuance" below), the notification system 1 performs notification issuance to promote recognition in regard to presence of the counterpart vehicles VC and VB between the oncoming vehicle VB and the crossing vehicle VC. Specifically, the notification system 1 performs notification issuance to promote the oncoming vehicle VB to recognize the presence of another vehicle (that is, the crossing vehicle VC) approaching the intersection CS from the right side of the oncoming vehicle VB itself, and performs notification issuance to promote the crossing vehicle VC to recognize the presence of another vehicle (that is, the oncoming vehicle VB) approaching the intersection CS from the left side of the crossing vehicle VC itself. The notification issuance performed between the oncoming vehicle VB and the crossing vehicle VC at the time of the simultaneous notification issuance corresponds to the "third notification issuance".(Internal Configuration of Controller)

[0059] Fig. 2 is a schematic diagram illustrating an internal configuration of the controller 101a included in the right turning vehicle VA, Fig. 3 is a schematic diagram illustrating an internal configuration of the controller 101b included in the oncoming vehicle VB, and Fig. 4 is a schematic diagram illustrating an internal configuration of the controller 101c included in the crossing vehicle VC. The internal configuration of each of the controllers 101a, 101b and 101c will be described in turn on the basis of Figs. 2 to 4 and with reference to Fig. 14 as needed.

[0060] As illustrated in Fig. 2, the controller 101a includes a host vehicle position detection unit B111a, a first other vehicle position detection unit B112a, a second other vehicle position detection unit B113a, a road map storage unit B114a, a right turn intention detection unit B115a, a driving state detection unit B116a, a first notification issuance timing detection unit B117a, a second notification issuance timing detection unit B118a, a first notification issuing unit B119a, a second notification issuing unit B120a, a simultaneous notification issuance determination unit B121a and a determination area setting unit B122a. A function of each of these units B111a to B122a is realized in a software manner by the central processing unit included in the controller 101a reading a computer program stored in the storage device and operating in accordance with instructions of the program.

[0061] The host vehicle position detection unit B111a detects the current position Pa of the right turning vehicle VA, which is a host vehicle. The detection of the current position Pa of the host vehicle performed by the host vehicle position detection unit B111a is based on an output signal from the position sensor 111a included in the right turning vehicle VA.

[0062] The first other vehicle position detection unit B112a detects the current position Pb of the oncoming vehicle VB, which is one of other vehicles. The detection of the current positions Pb by the first other vehicle position detection unit B112a is performed by reading position information indicating the current position Pb from vehicle information acquired from the oncoming vehicle VB via the communication device 121a included in the right turning vehicle VA.

[0063] The second other vehicle position detection unit B113a detects the current position Pc of the crossing vehicle VC, which is another one of other vehicles. The detection of the current positions Pc by the second other vehicle position detection unit B113a is performed by reading position information indicating the current position Pc from vehicle information acquired from the crossing vehicle VC via the communication device 121a included in the right turning vehicle VA.

[0064] The road map storage unit B114a stores a road map. In the present embodiment, the current positions Pa, Pb and Pc of the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC are coordinates of latitudes and longitudes indicating these positions Pa, Pb and Pc. The road map storage unit B114a extracts a map of a range or a section including the intersection CS and its surrounding area in the road map and specifies the current positions Pa, Pb and Pc of the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC on the road map. In the road map, identifiers (hereinafter, referred to as "link IDs") corresponding to lanes leading to the intersection CS, such as the right turn lanes L11 and L21, the opposite lanes L12 and L22, and the crossing lane L31 are assigned and are stored to correspond to the lanes L11, L21, L12, L22 and L31 respectively. It is possible to distinguish the lane in which a target vehicle is present or is traveling by specifying the position on the road map.

[0065] The right turn intention detection unit B115a detects that the right turning vehicle VA has a right turn intention. The right turn intention detection by the right turn intention detection unit B115a can be performed with an output signal from the right turn signal switch 113a included in the right turning vehicle VA, and in a case where the right turn lane L11 is a lane only for right turn, the detection can also be performed by reading the link ID associated with the lane where the vehicle is traveling from the road map and detecting that the right turning vehicle VA is present in the right turn lane L11.

[0066] The driving state detection unit B116a detects the vehicle speeds VSPb, VSPc of the oncoming vehicle VB and the crossing vehicle VC. The driving state detection unit B116a detects the vehicle speeds VSPb, VSPc by reading vehicle speed information indicating the respective one of the vehicle speeds VSPb, VSPc from the vehicle information acquired from the oncoming vehicle VB and the crossing vehicle VC via the communication device 121a included in the right turning vehicle VA.

[0067] The first notification issuance timing setting unit B117a detects that the right turning vehicle VA is present at a predetermined position relative to the intersection CS, specifically, the right turning vehicle VA is present at a predetermined distance from a center position (that is, the intersection center) CTR of the intersection CS or is located at a position closer to the intersection center CTR than the predetermined distance after the right turn intention detection unit B115a detects the right turn intention, in other words, after the right turning vehicle VA indicates the right turn intention by entering the right turning lane L11 or operating the right turn signal or the like on the basis of the current position Pa of the right turning vehicle VA on the road map. Then, the first notification issuance timing setting unit B117a sets the timing at which the presence of the right turning vehicle VA at the predetermined position relative to the intersection CS as a first notification issuance timing. The first notification issuance timing set by the first notification issuance timing setting unit B117a is a timing to perform notification issuance for information presentation in the right turning vehicle VA.

[0068] The second notification issuance timing setting unit B118a monitors behaviors of the right turning vehicle VA after the setting of the first notification issuance timing. The second notification issuance timing setting unit B118a regards points at which a path Tra where the right turning vehicle VA travels when the right turning vehicle VA passes the intersection CS and paths TRb and TRc where the oncoming vehicle VB and the crossing vehicle VC travel when they pass the intersection CS intersect each other as "predicted collision points" CPP1 and CPP2 and detects that the right turning vehicle VA is traveling toward the predicted collision points CPP1 and CPP2 or that the right turning vehicle VA has approached the predicted collision points CPP1 and CPP2 by a predetermined distance after the setting of the first notification issuance timing on the basis of the current position Pa of the right turning vehicle VA on the road map. Then, the second notification issuance timing setting unit B118a sets the timing at which any of these behaviors is detected in the right turning vehicle VA as a second notification issuance timing. Specifically, the second notification issuance timing setting unit B118a sets the second notification issuance timing in regard to the oncoming vehicle VB in a case where any of these behaviors is detected in the right turning vehicle VA in the relationship with the predicted collision point CPP1, or sets the second notification issuance timing in regard to the crossing vehicle VC in a case where any of these behaviors is detected in the relationship with the predicted collision point CPP2. The second notification issuance timing set by the second notification issuance timing setting unit B118a is a timing to perform notification issuance for alarm in the right turning vehicle VA.

[0069] Figs. 15 and 17 are schematic diagrams illustrating a positional relationship between the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC at a timing when the right turning vehicle VA exceeds the stop line SL1 in the right turn lane L11 and enters the intersection CS. Figs. 15 and 17 illustrate only the right turn lane L11 and the opposite straight lane L22 in the road R with two lanes on each side by simplifying the illustration of the road R (the same applies to Figs. 16, 18 and 19, which will be described later).

[0070] In the present embodiment, an intersection area ACS is set as a determination criterion to recognize the relative positional relationship between the right turning vehicle VA and the intersection CS. The intersection area ACS is set to overlap a path TRa along which the right turning vehicle VA travels when passing the intersection CS, and the presence of the right turning vehicle VA at a predetermined relative position to the intersection CS is detected by arrival of the right turning vehicle VA at the intersection area ACS or entrance thereof into the intersection area ACS after displaying its right turn intention. The intersection area ACS is set as a circular area that has a predetermined radius concentrically with the intersection center CTR. Figs. 15 to 19 illustrate the intersection area ACS by two-dotted chain lines, illustrate the traveling paths TRb, TRc of the oncoming vehicle VB and the crossing vehicle VC by one-dotted chain lines respectively, and illustrate a predicted collision area ACP (ACP1, ACP2), which will be described later, by dashed lines.

[0071] Figs. 16 and 18 are schematic diagrams illustrating a positional relationship among the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC at a timing at which the right turning vehicle VA moves ahead inside the intersection CS and approaches the intersection center CTR after entering the intersection CS.

[0072] In the present embodiment, the predicted collision area ACP (ACP1, ACP2) with the predicted collision point CPP (CPP1, CPP2) included at its center is set as an area that is different from the intersection area ACS. Figure 16 illustrates the predicted collision point CPP1 of the right turning vehicle VA with the oncoming vehicle VB, along with the predicted collision area ACP1 defined around CPP1. Figure 18 illustrates the predicted collision point CPP2 of the right turning vehicle VA with the crossing vehicle VC, along with the predicted collision area ACP2 defined around CPP2.

[0073] After entering the intersection area ACS, it is detected whether the right turning vehicle VA is either traveling toward the predicted collision point CPP1 or CPP2 inside the intersection area ACS or is present inside the predicted collision area ACP1 or ACP2, in relation to the oncoming vehicle VB and the crossing vehicle VC, respectively. Specifically, in relation to the oncoming vehicle VB, as shown in Fig. 16, it is detected whether the right turning vehicle VA is traveling toward the predicted collision point CPP1 inside the intersection area ACS or is present inside the predicted collision area ACP1. Similarly, in relation to the crossing vehicle VC, as shown in Fig. 18, it is detected whether the right turning vehicle VA is traveling toward the predicted collision point CPP2 inside the intersection area ACS or is present inside the predicted collision area ACP2. The predicted collision areas ACP1 and ACP2 are defined as circular regions with a predetermined radius and a smaller area than that of the intersection area ACS.

[0074] In the present embodiment, the predicted collision points CPP1 and CPP2, as well as the predicted collision areas ACP1 and ACP2, are individually defined under the relationship with the oncoming vehicle VB and the crossing vehicle VC, respectively. However, this is not limiting, and a common predicted collision point CPP and predicted collision area ACP may instead be defined for both the oncoming vehicle VB and the crossing vehicle VC. For example, a region within the intersection CS where the opposite straight lane L22 and the crossing lane L31 overlap may be identified, and the center of this overlapping region may be set as the predicted collision point CPP. Based on this point CPP, a predicted collision area ACP can then be defined. Alternatively, the predicted collision point CPP and predicted collision area ACP defined in relation to either the oncoming vehicle VB or the crossing vehicle VC may also be applied to the other.

[0075] The shape of the intersection area ACS is not limited to the circular shape and may be a shape (for example, a quadrangular shape having four corners at a corner cut) following a range in which the two intersecting roads overlap or may be a shape within a range surrounded by the stop lines SL1, SL2, SL3, SL4 (Fig. 14) provided in the intersecting roads, respectively. The same applies to the predicted collision area ACP, and it is possible to set a shape other than the circular shape, such as a quadrangular shape (for example, a quadrangular shape having two sides that are parallel to a road boundary line defining the opposite straight lane L22).

[0076] The first notification issuing unit B119a outputs a command signal to issue a notification for information presentation to the HMI device 131a included in the host vehicle, which is the right turning vehicle VA, under a condition that a notification issuance condition defined respectively in advance in regard to the positions Pb, Pc of the oncoming vehicle VB and the crossing vehicle VC is established at a first notification issuance timing set by the first notification issuance timing setting unit B117a.

[0077] The notification issuance condition at the first notification issuance timing is that the oncoming vehicle VB or the crossing vehicle VC is present at a first predetermined distance (hereinafter, referred to as an "information presentation distance") Dth1, which is relatively long, from the intersection CS or at a position closer to the intersection CS than the first predetermined distance Dth1. In the present embodiment, the distance from the outer edge of the predicted collision area ACP1, ACP2, specifically, an intersecting point between the traveling path TRb, TRc of the oncoming vehicle VB or the crossing vehicle VC and the circle (the circle illustrated by the dashed line in the drawings) defining the outer edge of the predicted collision area ACP1, ACP2 to the oncoming vehicle VB or the crossing vehicle VC, as illustrated in Figs. 15 and 17, is employed as a distance Db from the intersection CS to the oncoming vehicle VB or a distance Dc from the intersection CS to the crossing vehicle VC. In other words, the first notification issuing unit B119a determines, as a notification issuance condition in relation to the oncoming vehicle VB, whether at the first notification issuance timing, the oncoming vehicle VB is within the information presentation distance Dth1 from the outer edge of the predicted collision area ACP1. Similarly, as a notification issuance condition in relation to the crossing vehicle VC, it determines whether at the first notification issuance timing, the crossing vehicle VC is within the information presentation distance Dth1 from the outer edge of the predicted collision area ACP2.

[0078] The HMI device 131a that has received the command signal from the first notification issuing unit B119a issues a notification using display and sound to promote the driver of the right turning vehicle VA to recognize that one of other vehicles, or the oncoming vehicle VB, traveling toward the intersection CS in the opposite straight lane L22 is present and that another one of other vehicles, or the crossing vehicle VC, traveling toward the intersection CS in the crossing lane L31 is present. The notification issuance performed by the first notification issuing unit B119a is notification issuance to present information for relatively low urgency in regard to collision between the right turning vehicle VA and the oncoming vehicle VB or collision between the right turning vehicle VA and the crossing vehicle VC.

[0079] The second notification issuing unit B120a outputs a command signal to issue a notification for alarm to the HMI device 131a under a condition that a notification issuance condition defined respectively in advance in regard to the position Pb, Pc of the oncoming vehicle VB or the crossing vehicle VC is established at a second notification issuance timing set by the second notification issuance timing setting unit B118a.

[0080] The notification issuance condition at the second notification issuance timing is that the oncoming vehicle VB or the crossing vehicle VC is present at a second predetermined distance (hereinafter, referred to as an "alarm distance") Dth2, which is shorter than the information presentation distance Dth1, from the intersection CS or at a position closer to the intersection CS than the second predetermined distance Dth2. The second notification issuing unit B120a determines, as a notification issuance condition in relation to the oncoming vehicle VB, whether at the second notification issuance timing, the oncoming vehicle VB is within the alarm distance Dth2 from the outer edge of the predicted collision area ACP1. Similarly, as a notification issuance condition in relation to the crossing vehicle VC, it determines whether at the second notification issuance timing, the crossing vehicle VC is within the alarm distance Dth2 from the outer edge of the predicted collision area ACP2.

[0081] The notification issuance for alarm is notification issuance using distinct display and sound differing from the information presentation, and the HMI device 131a that has received the command signal from the second notification issuing unit B120a issues a notification to promote the driver of the right turning vehicle VA to recognize higher urgency in regard to collision between the right turning vehicle VA and the oncoming vehicle VB or collision between the right turning vehicle VA and the crossing vehicle VB using display and sound. The notification issuance performed by the second notification issuing unit B120a is notification issuance that is more prominent and more visually or auditorily appealing to the driver as compared with the notification issuance performed by the first notification issuing unit B119a.

[0082] The first notification issuing unit B119a and the second notification issuing unit B120a can also provide a notification that the notification in each mode has been issued to the oncoming vehicle VB or the crossing vehicle VC via the communication device 121a in accordance with the output of the command signal to the HMI device 131a, and promote a notification to be issued in an appropriate mode, specifically a notification for information presentation or alarm, in accordance with urgency in regard to collision against the host vehicle (that is, the right turning vehicle VA).

[0083] Fig. 13 is an explanatory diagram illustrating a method of calculating the information presentation distance Dth1 and the alarm distance Dth2.

[0084] The information presentation distance Dth1 and the alarm distance Dth2 can be set for both the oncoming vehicle VB and the crossing vehicle VC using similar procedures. Taking the case of the oncoming vehicle VB as an example, the information presentation distance Dth1 and the alarm distance Dth2 are calculated as a distance by which the oncoming vehicle VB is expected to travel before stopping after the notification issuance, that is, the distance required by the oncoming vehicle VB to stop on the basis of the vehicle speed VSPb of the oncoming vehicle VB and deceleration degrees DEC1 and DEC2 set in advance in accordance with the modes of the notification issuance.

[0085] Specifically, the information presentation distance Dth1 is calculated by adding the distances for which the oncoming vehicle VB is expected to travel for a break reaction time PRD1 and a deceleration time PRD2 on the basis of the vehicle speed VSPb (= V1) of the oncoming vehicle VB at the first notification issuance timing set by the first notification issuance timing setting unit B117a. The break reaction time PRD1 is a total time of a reaction time required for perception, judgment, and operation before the driver actually performs a brake operation after the notification issuance and an operation delay time for the system, hydraulic equipment, and the like in response to the brake operation. In the present embodiment, the break reaction time PRD1 is set in advance as a constant time (= ΔT). The deceleration time PRD2 is a time required for the vehicle to come to a stop after the brake actually starts to work and can be calculated on the basis of the vehicle speed VSPb and the deceleration degree DEC1 (PRD2 = V1 / DEC1). The deceleration degree DEC1 is, for example, -0.1 G. In this manner, the calculation of the information presentation distance Dth1 is given by Equation (1) below. Dth 1 = V 1 × ΔT + V 1 × V 1 / DEC 1 / 2

[0086] Although the alarm distance Dth2 is similarly calculated by adding the distance for which the straight traveling vehicle VB is expected to travel for each of the break reaction time PRD1 and the deceleration time PRD2, the deceleration degree DEC2 which is different from that used to calculate the information presentation distance Dth1 is employed. The deceleration degree DEC2 for calculating the alarm distance is a higher deceleration degree than the deceleration degree DEC1 for calculating the information presentation distance, in other words, a deceleration degree having a larger absolute value than that the deceleration degree DEC1 (|DEC1| < |DEC2|). The deceleration degree DEC2 is, for example, -0.2 G. Specifically, it is given by Equation (2) below. The vehicle speed V1 used in calculating the alarm distance Dth2 is the vehicle speed VSPb of the oncoming vehicle VB at the second notification issuance timing. However, for simplicity, the vehicle speed VSPb at the first notification issuance timing may also be used. Dth 2 = V 1 × ΔT + V 1 × V 1 / DEC 2 / 2

[0087] Returning to Fig. 2, a simultaneous notification issuance determination unit B121a determines whether the notification for information presentation or for alarm has been performed in each of the relationship with the oncoming vehicle VB and the relationship with the crossing vehicle VC, in other words, whether or not the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC have been simultaneously performed by the first and second notification issuing units B119a and B120a.

[0088] Then, in a case where the notification issuance in the relationship with the oncoming vehicle VB and the notification issuance with the crossing vehicle VC have been simultaneously performed in the right turning vehicle VA, in other words, in a case where it is determined whether the right turning vehicle VA is in a situation of the simultaneous notification issuance, and the right turning vehicle VA is determined to be in the situation of the simultaneous notification issuance, the simultaneous notification issuance determination unit B121a outputs signals (hereinafter, referred to as "notification issuance status notice signals") to notify the controller 101b and the controller 101c of the fact that the right turning vehicle VA is in the situation of the simultaneous notification issuance. In the present embodiment, a mode for each of the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC, specifically, which of notification issuance for information presentation and notification issuance for alarm the notification issuance corresponds to is also provided in the notification when the notification issuance status notice signals are output. Here, in a case where the right turning vehicle VA is in the situation of the simultaneous notification issuance, the first notification issuing unit B119a and the second notification issuing unit B120a may perform notification issuance in accordance with a priority order defined in advance. Specifically, in a case where the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC are performed in mutually different modes, that is, in a case where one of them is notification issuance for information presentation while the other one is notification issuance for alarm, priority is placed on the notification issuance for alarm. Then, in a case where both of them are notification issuance for information presentation, priority is placed on notification issuance with a shorter information presentation distance Dth1. Similarly, in a case where both of them are notification issuance for alarm, priority is placed on notification issuance with a shorter alarm distance Dth2. This avoids confusion of the drivers by the counterpart vehicles VB and VC simultaneously performing a plurality of different notification issuance processes.

[0089] In contrast, the controller 101b performs notification issuance to promote the driver of the host vehicle (that is, the oncoming vehicle VB) to recognize presence of another vehicle approaching the intersection CS other than the right turning vehicle VA, specifically, another vehicle (that is, the crossing vehicle VC) that may enter the intersection CS from the right side of the host vehicle. Furthermore, the controller 101c performs notification issuance to promote the driver of the host vehicle (that is, the crossing vehicle VC) to recognize presence of another vehicle approaching the intersection CS other than the right turning vehicle VA, specifically, another vehicle (that is, the oncoming vehicle VB) that may enter the intersection CS from the left side of the host vehicle.

[0090] In the following description, the vehicle that is a target of the notification issuance performed between the oncoming vehicle VB and the crossing vehicle VC at the time of the simultaneous notification issuance will be referred to as an "intersection entering vehicle". In the present embodiment, the crossing vehicle VC corresponds to the intersection entering vehicle for the oncoming vehicle VB, while the oncoming vehicle VB corresponds to the intersection entering vehicle for the crossing vehicle VC.

[0091] The determination area setting unit B122a sets the intersection area ACS and the predicted collision areas ACP (ACP1 and ACP2). The determination area setting unit B122a associates these areas ACS and ACP with the road map at a timing before the right turning vehicle VA reaches the intersection CS after indicating the right turn intention, and sets the areas ACS and ACP on the map in the range or the section extracted by the road map storage unit B114a in the present embodiment.

[0092] In the present embodiment, the controller 101a included in the right turning vehicle VA and the controllers 101b, 101c included respectively in the oncoming vehicle VB and the crossing vehicle VC have basically similar configurations and include mutually corresponding elements.

[0093] As illustrated in Fig. 3, the controller 101b includes a host vehicle position detection unit B111b, an other vehicle position detection unit B112b, a road map storage unit B114b, a right turn intention detection unit B115b, a driving state detection unit B116b, a first notification issuance timing setting unit B117b, a second notification issuance timing setting unit B118b, a first notification issuing unit B119b, and a second notification issuing unit B120b, a determination area setting unit B122b, an intersection entering vehicle detection unit B123b and a third notification issuing unit B124b. Differences between an internal configuration of the controller 101b and that of the controller 101a will be mainly described below.

[0094] The host vehicle position detection unit B111b is adapted to detect the current position Pb of the oncoming vehicle VB, which is the host vehicle, and the detection of the current position Pb is based on an output signal from the position sensor 111b included in the oncoming vehicle VB.

[0095] The other vehicle position detection unit B112b is adapted to detect the current position Pa of the right turning vehicle VA, which is another vehicle, and the detection of the current position Pa is based on reading of position information indicating the current position Pa from vehicle information acquired from the right turning vehicle VA via the communication device 121b included in the host vehicle, or the oncoming vehicle VB.

[0096] Similarly to the road map storage unit B114a, the road map storage unit B114b stores a road map that includes the intersection CS and includes the assigned link ID of each lane leading to the intersection CS and specifies the current positions Pb and Pa of the oncoming vehicle VB and the right turning vehicle VA, respectively, on the road map. Although the road maps stored in the road map storage units B114b and B114a may have different levels of accuracy, both the maps employ an accuracy that is compatible with satellite positioning using GNSS in the present embodiment.

[0097] The right turn intention detection unit B115b is adapted to detect a right turn intention of the right turning vehicle VA, and the detection the right turn intention is based on identification of the link ID of the lane where the right turning vehicle VA is present from the current position Pa of the right turning vehicle VA or reading of information indicating an operating status of the right turn signal from vehicle information acquired from the right turning vehicle VA via the communication device 121b. It is also possible to include the link IDs of the lanes where the vehicles VA and VB are present in vehicle information exchanged between the oncoming vehicle VB and the right turning vehicle VA and to detect the right turn intention of the right turning vehicle VA on the basis of the link IDs acquired through communication.

[0098] The driving state detection unit B116b is adapted to detect the vehicle speed VSPa of the right turning vehicle VA as a driving state of the right turning vehicle VA, and the detection of the vehicle speed VSPa is based on reading of vehicle speed information indicating the vehicle speed VSPa from vehicle information acquired from the right turning vehicle VA via the communication device 121b.

[0099] The first notification issuance timing setting unit B117b detects that the right turning vehicle VA is located at a predetermined relative position to the intersection CS after showing its right turn intention based on the current position Pa of the right turning vehicle VA on the road map. Specifically, the first notification issuance timing setting unit B117b compares the current position Pa of the right turning vehicle VA with the intersection area ACS and detects that the right turning vehicle VA has arrived at the intersection area ACS or has entered the intersection area ACS. Then, the first notification issuance timing setting unit B117b sets the timing at which it detects this as the first notification issuance timing. The first notification issuance timing set by the first notification issuance timing setting unit B117b is the timing at which the oncoming vehicle VB executes the notification issuance for information presentation.

[0100] The size and the shape of the intersection area ACS may be the same or different between the controller 101a and the controller 101b. It is possible to differentiate the shape of the intersection area ACS between those controllers 101a, 101b in accordance with a drivers' selection or trends of driving states at the time of passing the intersection CS, for example.

[0101] The second notification issuance timing setting unit B118b monitors a behavior of the right turning vehicle VA after the right turning vehicle VA enters the intersection CS based on its current position Pa on the road map and detects that the right turning vehicle VA is traveling toward the predicted collision point CPP1 in the intersection area ACS or is present inside the predicted collision area ACP1 after entering the intersection area ACS. Then, the second notification issuance timing setting unit B118b sets the timing at which it detects any of these behaviors in the right turning vehicle VA as the second notification issuance timing. The second notification issuance timing set by the second notification issuance timing setting unit B118b is the timing at which the oncoming vehicle VB executes the notification issuance for alarm.

[0102] Although the size and the shape of the predicted collision area ACP1 may be different between the controller 101a and the controller 101b, similar setting is adopted for both in the present embodiment. The predicted collision area ACP1 may be configured with the same size and shape independently by both the controller 101a and the controller 101b, or coordinate information of the predicted collision area ACP1 set in one of the controllers 101a and 101b may be provided to the other controller through vehicle-to-vehicle communication and adopted as a common setting by both controllers 101a and 101b.

[0103] The first notification issuing unit B119b outputs a command signal to issue the notification for information presentation to the HMI device 131b included in the host vehicle (that is, the oncoming vehicle VB) under a condition that the predetermined notification issuance condition related to the position Pb of the oncoming vehicle VB is established at the first notification issuance timing set by the first notification issuance timing setting unit B117b. The notification issuance condition at the first notification issuance timing is that the oncoming vehicle VB is located at the information presentation distance Dth1 from the intersection CS or is present at a position closer to the intersection CS than the information presentation distance Dth1.

[0104] The HMI device 131b that has received the command signal from the first notification issuing unit B119b issues a notification to promote the driver of the oncoming vehicle VB to recognize that the right turning vehicle VA which the driver should pay attention to is present in the right turn lane L11 in the opposite lanes using display and sound. Similarly to the above description, the notification issuance performed by the first notification issuing unit B119b is notification issuance to present information for relatively low urgency in regard to collision between the oncoming vehicle VB and the right turning vehicle VA.

[0105] The second notification issuing unit B120b outputs a command signal to issue a notification for alarm to the HMI device 131b under a condition that the predetermined notification issuance condition related to the position Pb of the oncoming vehicle VB is established at the second notification issuance timing set by the second notification issuance timing setting unit B118b. The notification issuance condition at the second notification issuance timing is that the oncoming vehicle VB is located at the alarm distance Dth2 from the intersection CS or is present at a position closer to the intersection CS than the alarm distance Dth2.

[0106] The HMI device 131b that has received the command signal from the second notification issuing unit B120b issues a notification to promote the driver of the oncoming vehicle VB to recognize higher urgency in regard to collision between the oncoming vehicle VB and the right turning vehicle VA using display and sound. Similarly to the above description, the notification issuance performed by the second notification issuing unit B120a is also notification issuance that is more prominent and more visually or auditorily appealing to the driver.

[0107] The first notification issuing unit B119b and the second notification issuing unit B120b can also notify the right turning vehicle VA of the fact that the notification in each mode has been issued via the communication device 121b in accordance with the output of the command signal to the HMI device 131b.

[0108] The determination area setting unit B122b sets the intersection area ACS and the predicted collision area ACP1. The determination area setting unit B122b sets these areas ACS and ACP1 on the map in the range or the section extracted by the road map storage unit B114b at a timing before the right turning vehicle VA reaches the intersection CS and after the right turn intention of the right turning vehicle VA is detected.

[0109] In the present embodiment, the setting of the intersection area ACS and the predicted collision area ACP1 by the determination area setting unit B122b follows the same procedure as that for the setting of each of the areas ACS and ACP1 by the determination area setting unit B122a.

[0110] In a case where the controller 101b receives the notification issuance status notice signal from the controller 101a included in the right turning vehicle VA, in other words, in a case where the right turning vehicle VA is in the situation of the simultaneous notification issuance, the controller 101b performs notification issuance to promote the driver of the oncoming vehicle VB, which is the host vehicle, to recognize presence of another vehicle approaching the intersection CS other than the right turning vehicle VA, that is, the crossing vehicle VC, which is the intersection entering vehicle.

[0111] In addition to the previously mentioned configuration, the controller 101b includes the intersection entering vehicle detection unit B123b and the third notification issuing unit B124b.

[0112] The intersection entering vehicle detection unit B123b detects the intersection entering vehicle for the oncoming vehicle VB. The detection of the intersection entering vehicle by the intersection entering vehicle detection unit B123b is performed by reading information (that is, a notification issuance status notice) indicating a notification issuance execution status in the right turning vehicle VA from the vehicle information received from the controller 101a via the communication device 121b. As previously mentioned, the notification issuance status notice signal is accompanied by the signal indicating the mode when the notification issuance is performed in the present embodiment. The controller 101b can thus detect that the right turning vehicle VA is in the situation of the simultaneous notification issuance and also detect modes for the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC. The intersection entering vehicle detection unit B123b detects the intersection entering vehicle by reception of the notification issuance status notice signal.

[0113] In a case where the intersection entering vehicle detection unit B123b detects the intersection entering vehicle, the third notification issuing unit B124b outputs a command signal to perform notification issuance to promote recognition of the presence of the intersection entering vehicle other than the right turning vehicle VA, as another vehicle to which attention is to be paid at the time of entering the intersection CS to the alarm device 132b. As previously mentioned, the crossing vehicle VC corresponds to the intersection entering vehicle for the oncoming vehicle VB.

[0114] The alarm device 132b that has received the command signal from the third notification issuing unit B124b performs notification issuance for the driver of the oncoming vehicle VB to pay attention to another vehicle (that is, the crossing vehicle VC) approaching the intersection CS from the right side of the host vehicle through display and sound.

[0115] The notification issuance for alerting performed by the third notification issuing unit B124b can be performed using different display or sound in accordance with the notification issuance execution status in the right turning vehicle VA, specifically, the mode of each of the notification issuance performed between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance performed between the right turning vehicle VA and the crossing vehicle VC.

[0116] For example, in a case where the notification issuance for information presentation is performed between the right turning vehicle VA and the oncoming vehicle VB and between the right turning vehicle VA and the crossing vehicle VC, notification issuance to promote the oncoming vehicle VB to pay attention at a low level as attention to the crossing vehicle VC is performed because the crossing vehicle VC is located at a position relatively far from the intersection CS. Similarly, notification issuance to promote the right turning vehicle VA to pay attention to the crossing vehicle VC at a low level is performed in a case where the notification issuance for alarm is performed between the right turning vehicle VA and the oncoming vehicle VB while the notification issuance for information presentation is performed between the right turning vehicle VA and the crossing vehicle VC as well. In contrast, in a case where the notification issuance for information presentation is performed between the right turning vehicle VA and the oncoming vehicle VB while the notification issuance for alarm is performed in the relation between the right turning vehicle VA and the crossing vehicle VC, notification issuance to promote the right turning vehicle VA to pay attention at a high level as attention to the crossing vehicle VC is performed because the crossing vehicle VC is located at a position close to the intersection CS.

[0117] In the present embodiment, the notification issuance based on the command signal from the third notification issuing unit B124b, that is, the notification issuance for alerting in regard to the intersection crossing vehicle is stopped in a case where notification issuance for alarm is performed between the right turning vehicle VA and the oncoming vehicle VB and between the right turning vehicle VA and the crossing vehicle VC. This is for avoiding confusion of the driver due to overlapping with the notification issuance (that is, notification issuance for alarm) by the second notification issuing unit B120a.

[0118] Configuration differences between the controller 101c and the controller 101b will be mainly described.

[0119] The controller 101c performs notification issuance to promote the driver of the oncoming vehicle VC, which is the host vehicle, to recognize presence of another vehicle approaching the intersection CS other than the right turning vehicle VA, that is the oncoming vehicle VB, which is the intersection entering vehicle, in a case where the right turning vehicle VA is in the situation of the simultaneous notification issuance and the notification issuance status notice signal has been received from the controller 101a.

[0120] The controller 101c includes, as configurations related to detection of the intersection entering vehicle and notification issuance for alerting based on the detection, an intersection entering vehicle detection unit B123c and a third notification issuing unit B124c.

[0121] The intersection entering vehicle detection unit B123c detects the intersection entering vehicle for the crossing vehicle VC. The detection of the intersection entering vehicle by the intersection entering vehicle detection unit B123c is performed by reading information (that is, a notification issuance status notice) indicating the notification issuance execution status in the right turning vehicle VA from the vehicle information received from the controller 101a via the communication device 121c. Similarly, the notification issuance status notice signal is accompanied by a signal indicating the mode when the notification issuance is performed, and the controller 101c can detect that the right turning vehicle VA is in the situation of the simultaneous notification issuance and also the mode of each of the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC.

[0122] The third notification issuing unit B124c outputs a command signal to perform notification issuance to promote recognition of the presence of the intersection entering vehicle other than the right turning vehicle VA as another vehicle to which attention is to be paid at the time of entering the intersection CS to the alarm device 132c in a case where the intersection entering vehicle detection unit B123c detects the intersection entering vehicle. The oncoming vehicle VB corresponds to the intersection entering vehicle for the crossing vehicle VC.

[0123] The alarm device 132c that has received the command signal from the third notification issuing unit B124c performs notification issuance to promote the driver of the crossing vehicle VC to pay attention to another vehicle (that is, the oncoming vehicle VB) approaching the intersection CS from the left side of the host vehicle by display and sound.

[0124] Similarly, the notification issuance by the third notification issuing unit B124c can also be performed using different display or sound in accordance with the notification issuance execution status in the right turning vehicle VA, specifically, the mode of each of the notification issuance performed between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance performed between the right turning vehicle VA and the crossing vehicle VC.(Content of Notification Control in Right Turning Vehicle)

[0125] Figs. 5 to 8 are flowcharts illustrating content of notification control performed by the controller 101a included in the right turning vehicle VA. The flowchart in Fig. 5 illustrates an overall flow of the notification control, the flowchart in Fig. 6 illustrates content of processing (information presentation processing) executed by the right turning vehicle VA in regard to information presentation, and the flowchart in Fig. 7 illustrates content of processing (alarm processing) executed by the right turning vehicle VA in regard to an alarm. The flowchart in Fig. 8 illustrates content of the processing executed in section A in Fig. 5. The information presentation processing and the alarm processing are performed as parts of the notification control. The controller 101a performs the notification control every predetermined time in a case where an intersection is detected in a road in front of the host vehicle (that is, the right turning vehicle VA).

[0126] In the flowchart illustrated in Fig. 5, various kinds of control information used for the notification control is read in S111. The control information read in S111 includes the current position Pa, the vehicle speed VSPa and the link ID of the right turning vehicle VA, which is a host vehicle, and the current position Pb, the vehicle speed VSPb and the link ID of the oncoming vehicle VB and the crossing vehicle VC, which are other vehicles. The control information may include information regarding operating statuses of the right turn signals in the right turning vehicle VA, the oncoming vehicle VB and the crossing vehicle VC.

[0127] In S112, whether or not another vehicle traveling toward the intersection CS in the opposite lane L22 or the crossing lane L31 to the lane L11 in which the right turning vehicle VA is present, in the present embodiment, the oncoming vehicle VB or the crossing vehicle VC has been detected is determined. The detection of the oncoming vehicle VB and the crossing vehicle VC is based on the link ID of each vehicle VB, VC. The processing proceeds to S113 in a case where the oncoming vehicle VB or the crossing vehicle VC is detected, or this control is ended in a case where any one of these other vehicles VB and VC are not detected.

[0128] In S113, whether or not a right turn intention of the right turning vehicle VA has been detected is determined. The detection of the right turn intention is based on an operating status of the right turn signal of the right turning vehicle VA. Additionally or alternatively, it is also possible to make the determination on the basis of the link ID of the right turning vehicle VA. The processing proceeds to S114 in a case where the right turn intention is detected, or this control is ended in a case where the right turn intention is not detected.

[0129] In S114, the intersection area ACS is set, and the predicted collision areas ACP (ACP1 and ACP2) are set. In the following description, the predicted collision area defined with reference to the predicted collision point CPP1 of the right turning vehicle VA against the oncoming vehicle VB will be referred to as a "first predicted collision area" ACP1, and the predicted collision area defined with reference to the predicted collision point CPP2 of the right turning vehicle VA against the crossing vehicle VC will be referred to as a "second predicted collision area" ACP2.

[0130] In S115, the current position Pa of the right turning vehicle VA on the road map is specified.

[0131] In S116, whether or not the right turning vehicle VA has entered the intersection area ACS is determined. In a case where the right turning vehicle VA is located at a position of the outer edge of the intersection area ACS or is located at a position closer to the intersection center CTR than the position of the outer edge, it is determined that the right turning vehicle VA has entered the intersection area ACS, and the processing proceeds to S117. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the intersection center CTR than the outer edge of the intersection area ACS, the right turning vehicle VA is determined not to have entered the intersection area ACS, and this control is ended.

[0132] In S117, information presentation processing is performed by the procedure illustrated in the flowchart in Fig. 6 in the relation to another vehicle detected in S112. Specifically, in a case where any one of the oncoming vehicle VB or the crossing vehicle VC is detected, the information presentation processing is performed in relation to the one of other vehicles VC and VC. In a case where both of them is detected, the information presentation processing is performed in relation to each of other vehicles VB and VC.

[0133] In S118, alarm processing is performed by the procedure illustrated in the flowchart in Fig. 7 in relation to another vehicle detected in S112. Specifically, in a case where any one of the oncoming vehicle VB or the crossing vehicle VC is detected, the alarm processing is performed in relation to the one of other vehicles VB and VC. In a case where both of them are detected, the alarm processing is performed in relation to each of other vehicles VB and VC.

[0134] In S411 in the flowchart illustrated in Fig. 8, whether or not the right turning vehicle VA is in the situation of the simultaneous notification issuance, in other words, whether or not the notification issuance for information presentation or alarm has been performed between the right turning vehicle VA and the oncoming vehicle VB and between the right turning vehicle VA and the crossing vehicle VC is determined. The processing proceeds to S412 in a case where the right turning vehicle VA is in the situation of the simultaneous notification issuance, or S412 is skipped, and the processing returns to the flowchart illustrated in Fig. 5 in a case where the right turning vehicle VA is not in the situation of the simultaneous notification issuance.

[0135] In S412, notification issuance status notice signals for notifying the controller 101b included in the oncoming vehicle VB and 101c included in the crossing vehicle VC of the fact that the right turning vehicle VA is in the situation of the simultaneous notification issuance are output.

[0136] Returning to Fig. 5, in S119, whether or not the right turning vehicle VA has passed the intersection CS is determined. The determination of whether or not the right turning vehicle VA has passed the intersection CS is made based on the fact that the right turning vehicle VA has left the intersection area ACS in the traveling direction after turning right. This control is ended in a case where the right turning vehicle VA has left the intersection area ACS and is determined to have passed the intersection CS, or the processing returns to S117 to repeat the information presentation processing and the alarm processing until the right turning vehicle VA passes the intersection CS in a case where the right turning vehicle VA is still in the intersection area ACS and determined not to have passed the intersection CS.

[0137] The information presentation processing and the alarm processing are performed either individually or in parallel for the notification issuance performed on the basis of the relationship with the oncoming vehicle VB and the notification issuance performed on the basis of the relationship with the crossing vehicle VC. In other words, the processing is performed in accordance with the procedure illustrated in the flowcharts in Figs. 6 and 7 on the basis of the relationship with the oncoming vehicle VB and the procedure similar to that illustrated in the flowcharts in Figs. 6 and 7 on the basis of the relationship with the crossing vehicle VC. For convenience, the information presentation processing and the alarm processing will be explained with reference to Figs. 6 and 7 by exemplifying a case where they are performed on the basis of the relationship with the oncoming vehicle VB.

[0138] In the flowchart illustrated in Fig. 6, various kinds of control information used for the information presentation processing is read in S211. The control information read in S211 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the oncoming vehicle VB.

[0139] In S212, the current positions Pa and Pb of the right turning vehicle VA and the oncoming vehicle VB on the road map are specified.

[0140] In S213, whether or not the right turning vehicle VA is located outside the predicted collision area ACP (ACP1) is determined. In a case where the right turning vehicle VA is located at a position between the outer edge of the intersection area ACS and the outer edge of the predicted collision area ACP1, the right turning vehicle VA is determined to be located outside the predicted collision area ACP1, and the processing proceeds to S214. On the other hand, in a case where the right turning vehicle VA is located at the outer edge of the predicted collision area ACP1 or a position closer to the predicted collision point CPP (CPP1) than the outer edge, the right turning vehicle VA is determined not to be located outside the predicted collision area ACP1, and the information presentation processing is ended.

[0141] In S214, the vehicle speed VSPa of the right turning vehicle VA is read.

[0142] In S215, whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than a predetermined vehicle speed VSP1 is determined. The predetermined vehicle speed VSP1 is a low speed that is low enough to determine that the right turning vehicle VA is in a low-speed traveling state and is a reduced speed (specifically, 10 km / hour), for example. In the present embodiment, it is determined that the driver of the right turning vehicle VA is paying attention to the surrounding situation to pass the intersection CS by the fact that the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1. The processing proceeds to S216 in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1, or the information presentation processing is ended in a case where the vehicle speed VSPa is greater than the vehicle speed VSP1. The predetermined vehicle speed VSP1 may be 0 km / hour, and in other words, S215 may be processing of determining whether or not the right turning vehicle VA has temporarily stopped inside the intersection area ACS. Furthermore, it is also possible to eliminate the processing in S215 itself, and the notification issuance for alarm may be prioritized over the notification issuance for information presentation in a case where a notification issuance condition for the information presentation (S220) and the notification issuance condition for the alarm (S320) are established at the same time.

[0143] In S216, the distance from intersection CS to the oncoming vehicle VB, in other words, a distance Db remaining in front of the oncoming vehicle VB until arriving at the intersection CS (hereinafter, referred to as an "intersection arrival distance") is calculated. As illustrated in Fig. 15, the intersection arrival distance Db is calculated as the distance from the outer edge of the predicted collision area ACP1 to the oncoming vehicle VB.

[0144] In S217, the vehicle speed VSPb of the oncoming vehicle VB is read.

[0145] In S218, the information presentation distance Dth1 is calculated. The calculation of the information presentation distance Dth1 is based on the vehicle speed VSPb of the oncoming vehicle VB and the first predetermined deceleration degree DEC1, in particular, the calculation follows Equation (1) described above.

[0146] In S219, whether or not the intersection arrival distance Db of the oncoming vehicle VB is equal to or less than the information presentation distance Dth1, in other words, whether the oncoming vehicle VB is located at the information presentation distance Dth1 from the intersection CS or is located at a position closer to the intersection CS than the information presentation distance Dth1 is determined. The processing proceeds to S220 in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1, or the information presentation processing is ended in a case where the intersection arrival distance Db is greater than the information presentation distance Dth1.

[0147] In S220, the notification issuance for information presentation is performed.

[0148] In the flowchart illustrated in Fig. 7, various kinds of control information used for the alarm processing is read in S311. The control information read in S311 includes the current position Pa and the vehicle speed VSPa of the right turning vehicle VA and the current position Pb and the vehicle speed VSPb of the oncoming vehicle VB.

[0149] In S312, the current positions Pa and Pb of the right turning vehicle VA and the oncoming vehicle VB on the road map are specified.

[0150] In S313, whether or not the right turning vehicle VA is located inside the predicted collision area ACP (ACP1) is determined. Specifically, in a case where the right turning vehicle VA is located at the outer edge of the predicted collision area ACP1 or at a position closer to the predicted collision point CPP (CPP1) than the outer edge, the right turning vehicle VA is determined to be located inside the predicted collision area ACP1, and the processing proceeds to S316. On the other hand, in a case where the right turning vehicle VA is located at a position farther from the predicted collision point CPP1 than the outer edge of the predicted collision area ACP1, the processing proceeds to S314.

[0151] In S314, the vehicle speed VSPa of the right turning vehicle VA is read.

[0152] In S315, whether or not the vehicle speed VSPa of the right turning vehicle VA is higher than the predetermined vehicle speed VSP1 is determined. The processing proceeds to S316 in a case where the vehicle speed VSPa is greater than the predetermined vehicle speed VSP1, or the alarm processing is ended in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1. The notification issuance for information presentation is performed through the information presentation processing in a case where the right turning vehicle VA is not inside the predicted collision area ACP1 and the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1 (see step S215 in the flowchart shown in Figure 6).

[0153] In this manner, a notification issuance timing for alarm is determined to have arrived on the basis of detection of a situation in which, after entering the intersection area ACS, the right turning vehicle VA has arrived at the predicted collision area ACP1 and has already been in the predicted collision area ACP1 or the right turning vehicle VA is traveling at a vehicle speed that is equal to or greater than a specific vehicle speed toward the predicted collision point CPP1 even outside the predicted collision area ACP1 and is approaching the predicted collision area ACP1 in S313 to S315, the processing in and after S316 is performed, and whether or not the notification issuance condition is established is determined.

[0154] In S316, the intersection arrival distance Db of the oncoming vehicle VB is calculated.

[0155] In S317, the vehicle speed VSPb of the oncoming vehicle VB is read.

[0156] In S318, the alarm distance Dth2 is calculated. The calculation of the alarm distance Dth2 is based on the vehicle speed VSPb of the oncoming vehicle VB and the second predetermined deceleration degree DEC2, in particular, the calculation follows Equation (2) described above.

[0157] In S319, whether or not the intersection arrival distance Db of the oncoming vehicle VB is equal to or less than the alarm distance Dth2, in other words, whether the oncoming vehicle VB is located at the alarm distance Dth2 from the intersection CS or is located at a position closer to the intersection CS than the alarm distance Dth2 is determined. The processing proceeds to S320 in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2, or the alarm processing is ended in a case where the intersection arrival distance Db is greater than the alarm distance Dth2.

[0158] In S320, the notification issuance for alarm is performed.(Content of Notification Control in Oncoming Vehicle and Crossing Vehicle)

[0159] The controller 101b and the controller 101c perform notification control following the same procedure in relation to the right turning vehicle VA. The following explanation describes the notification control performed by the controller 101b and the controller 101c, using the case of the controller 101b as an example, with reference to the flowcharts shown in Figs. 9 to 12.

[0160] The controller 101b performs the notification control every predetermined time in a case where an intersection CS is detected in a road in front of the host vehicle (that is, the oncoming vehicle VB). The execution cycles of the notification control may be the same or different between the controller 101a and the controller 101b. Furthermore, both the controllers 101a and 101b can also perform the notification control in a synchronized manner.

[0161] Each process performed by the controller 101a and the controller 101b in regard to the notification control corresponds to each other. Therefore, detailed description of the processes that are similar for both will be omitted in the following description.

[0162] In the flowchart illustrated in Fig. 9, the controller 101b reads various kinds of control information used for the notification control (S511), detects another vehicle that is present in the right turn lane L11 in the opposite lanes, that is, the right turning vehicle VA (S512), and then in S513, determines whether or not the right turn intention of the right turning vehicle VA has been detected. After detecting the right turn intention, the controller 101b sets the intersection area ACS and the predicted collision area ACP (ACP1) (S514), specifies the current position Pa of the right turning vehicle VA on the road map (S515), and determines whether or not the right turning vehicle VA has entered the intersection area ACS (S516). The procedure in and after S517 is executed in a case where the right turning vehicle VA has entered the intersection area ACS, or this control is ended in a case where the right turning vehicle VA has not entered the intersection area ACS. The information presentation processing is executed in S517, and the alarm processing is executed in S518. As shown in the flowchart of Fig. 12, in step S811, the controller 101b determines whether or not a notification issuance status signal has been received from the controller 101a, in other words, whether the vehicle notification system 1 is in a simultaneous notification issuance state due to the right turning vehicle VA. The processing proceeds to step S812 in a case where the notification issuance status signal is received, and the controller 101b issues an alert to prompt the driver to recognize the presence of the crossing vehicle VC, which is an intersection entering vehicle with respect to the oncoming vehicle VB, in other words, an alert is issued to draw the attention of the oncoming vehicle VB to the crossing vehicle VC. The information presentation processing and the alarm processing are repeated until the right turning vehicle VA passes the intersection CS (S519), and upon receiving each notification issuance status signal, the controller 101b issues the alert to raise awareness of the crossing vehicle VC.

[0163] In the flowchart illustrated in Fig. 10, the controller 101b reads various kinds of control information used for the information presentation processing, such as the current positions Pb and Pa of the oncoming vehicle VB and the right turning vehicle VA (S611), and specifies the current positions Pb and Pa of the oncoming vehicle VB and the right turning vehicle VA on the road map (S612). In S613, the controller 101b determines whether or not the right turning vehicle VA, which is another vehicle, is located outside the predicted collision area ACP (ACP1), and in a case where the right turning vehicle VA is determined to be located outside the predicted collision area ACP1, the controller 101b reads the vehicle speed VSPa of the right turning vehicle VA (S614), and determines whether or not the vehicle speed VSPa of the right turning vehicle VA is equal to or less than the predetermined vehicle speed VSP1 (S615). The processing in and after S616 is performed in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1, or the information presentation processing is ended in a case where the vehicle speed VSPa is greater than the predetermined vehicle speed VSP1. In a case where the operating status of the right turn signal is used to detect the right turn intention of the right turning vehicle VA, whether or not the operation of the right turn signal is being continued may be determined in addition to the processing in S613, and the processing in and after S614 may be executed in a case where the operation of the right turn signal is being continued. Then, the controller 101b calculates the intersection arrival distance Db of the oncoming vehicle VB (S616), which is the host vehicle, detects the vehicle speed VSPb of the oncoming vehicle VB (S617), and calculates the information presentation distance Dth1 (S618). The processing proceeds to S620 to issue a notification for information presentation in a case where the intersection arrival distance Db is equal to or less than the information presentation distance Dth1 (S619), or the information presentation processing is ended in a case where the intersection arrival distance Db is greater than the information presentation distance Dth1.

[0164] In the flowchart illustrated in Fig. 11, the controller 101b reads various kinds of control information used for the alarm processing such as the current positions Pb and Pa of the oncoming vehicle VB and the right turning vehicle VA (S711), and specifies the current positions Pb and Pa of the oncoming vehicle VB and the right turning vehicle VA on the road map (S712). In S713, the controller 101b determines whether or not the right turning vehicle VA, which is another vehicle, is located inside the predicted collision area ACP (ACP1), and in a case where the right turning vehicle VA is determined not to be located inside the predicted collision area ACP1, the controller 101b reads the vehicle speed VSPa of the right turning vehicle VA (S714), and determines whether or not the vehicle speed VSPa of the right turning vehicle VA is greater than the predetermined vehicle speed VSP1 (S715). The processing in and after S716 is performed in a case where the vehicle speed VSPa is greater than the predetermined vehicle speed VSP1, or the alarm processing is ended in a case where the vehicle speed VSPa is equal to or less than the predetermined vehicle speed VSP1. In a case where the operating status of the right turn signal is used to detect the right turn intention of the right turning vehicle VA, the fact that the operation of the right turn signal is being continued may be included in the condition of performing the processing as a premise of performing the processing in S713. Then, the controller 101b calculates the intersection arrival distance Db of the oncoming vehicle VB (S716), which is a host vehicle, reads the vehicle speed VSPb of the oncoming vehicle VB (S717), and calculates the alarm distance Dth2 (S718). The processing proceeds to S720 to issue a notification for alarm in a case where the intersection arrival distance Db is equal to or less than the alarm distance Dth2 (S719), or the alarm processing is ended in a case where the intersection arrival distance Db is greater than the alarm distance Dth2.(Description of Actions and Effects)

[0165] The vehicle notification system 1 according to the present embodiment has the aforementioned configuration. Effects obtained by the present embodiment will be described below.

[0166] Firstly, in a situation where vehicles (the right turning vehicle VA, the oncoming vehicle VB, and the crossing vehicle VC) that are present in the three lanes L11, L22, and L31 leading to the intersection CS are traveling toward the intersection CS, a notification issuance timing in accordance with the relative positional relationship between the right turning vehicle VA and the intersection CS is set after the right turn intention of the right turning vehicle VA is detected. Then, notification issuance in a predetermined mode is performed under a condition that a notification issuance condition (a first predetermined notification issuance condition, a second predetermined notification issuance condition) defined in relation to the positions Pb and Pc of the oncoming vehicle VB and the crossing vehicle VC is met, at the notification issuance timing. This makes it possible to perform the notification issuance (first notification issuance, second notification issuance) at an appropriate timing and in an appropriate mode in accordance with the degree of urgency of circumstances in regard to collision between the right turning vehicle VA and the oncoming vehicle VB or collision between the right turning vehicle VA and the crossing vehicle VC.

[0167] Here, in a case where both the first and second predetermined notification issuance conditions are met at the notification issuance timing, in other words, in a case where the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and the notification issuance between the right turning vehicle VA and the crossing vehicle VC are simultaneously performed, notification issuance (third notification issuance) to promote at least one of the oncoming vehicle VB or the crossing vehicle VC to recognize the presence of the other one of them is performed. It is thus possible to reduce circumstances where the oncoming vehicle VB and the crossing vehicle VC collide against each other at the intersection CS and to promote smooth and safe passage of the traffic participants at the intersection CS.

[0168] For example, in a case where the right turning vehicle VA enters the intersection CS and then decelerates or temporarily stops in response to notification issuance in relation to the oncoming vehicle VB, the oncoming vehicle VB and the crossing vehicle VC can recognize the deceleration or the temporary stop of the right turning vehicle VA as indication of an intention to wait for passing of the host vehicles, quickly pass the intersection CS, and reduce circumstances of contact with or collision against a vehicle approaching them from a lateral side (for example, the crossing vehicle VC for the oncoming vehicle VB).

[0169] Secondly, a reference for setting a notification issuance timing is obtained by setting the intersection area ACS and setting a timing at which or after the right turning vehicle VA reaches the intersection area ACS as the notification issuance timing, and notification issuance in a predetermined mode can thus be performed at an appropriate timing.

[0170] Then, the predicted collision areas ACP (ACP1 and ACP2) are set in addition to the intersection area ACS, and the first and second notification issuance timings are set as notification issuance timings. The second notification issuance timing is a notification issuance timing set in a case where the right turning vehicle VA shows a predetermined behavior (for example, traveling at a vehicle speed VSPa that is higher than the predetermined vehicle speed VSP1 outside the predicted collision area ACP) in the intersection area ACS after the first notification issuance timing is set. Then, notification issuance in a predetermined mode is performed under the condition that the predetermined notification issuance condition in accordance with the position Pb or Pc of the oncoming vehicle VB or the crossing vehicle VC is met at each of the first and second notification issuance timings.

[0171] Here, the modes of notification issuance, specifically, display or sound when the notification issuance for information presentation is performed and display or sound when the notification issuance for alarm is performed are differentiated at the first notification issuance timing and the second notification issuance timing when the notification issuance is performed. This makes it possible to perform the notification issuance in an appropriate mode in accordance with a degree of urgency of circumstances in regard to collision between the right turning vehicle VA and each of the oncoming vehicle VB and the crossing vehicle VC.

[0172] Thirdly, at the intersection CS with no traffic lights for regulating passage of the crossing vehicle VC, the timing at which the right turning vehicle VA and the oncoming vehicle VB enter the intersection CS and the timing at which the crossing vehicle VC enters the intersection CS may coincide with each other, and contact or collision may occur among these vehicles VA, VB, and VC in a case where the right turning vehicle VA and the oncoming vehicle VB can pass through the intersection CS. It is possible to reduce circumstances of collision between the oncoming vehicle VB and the crossing vehicle VC by performing notification issuance for alerting the oncoming vehicle VB and the crossing vehicle VC in regard to the mutual intersection entering vehicles, thereby promoting the oncoming vehicle VB to recognize the presence of the crossing vehicle VC, and promoting the crossing vehicle VC to recognize the presence of the oncoming vehicle VB at such an intersection CS.

[0173] In the above description, the notification issuance timings are set between the right turning vehicle VA and the oncoming vehicle VB and between the right turning vehicle VA and the crossing vehicle VC, the notification issuance in a predetermined mode is performed under the notification issuance condition is met, and in a case where the right turning vehicle VA is in the situation of the simultaneous notification issuance (that is, at the time of the simultaneous notification issuance of the right turning vehicle VA), the notification issuance status notice signal is output to each of the oncoming vehicle VB and the crossing vehicle VC. Then, the notification issuance to promote the oncoming vehicle VB to pay attention to the crossing vehicle VC, which is the intersection entering vehicle, is performed for the oncoming vehicle VB, while the notification issuance to promote the crossing vehicle VC to pay attention to the oncoming vehicle VB, which is the intersection entering vehicle, is performed for the crossing vehicle VC.

[0174] The notification issuance for alerting in regard to the intersection entering vehicle may be performed not only at the time of the simultaneous notification issuance but also in a case where the crossing vehicle VC approaching the intersection CS is detected during execution of the notification issuance between the right turning vehicle VA and the oncoming vehicle VB and in a case where the oncoming vehicle VB approaching the intersection CS is detected during execution of the notification issuance between the right turning vehicle VA and the crossing vehicle VC.

[0175] Specifically, the notification issuance to promote the oncoming vehicle VB and the crossing vehicle VC to pay attention to the intersection entering vehicles is performed in a case where the crossing vehicle VC traveling toward the intersection CS in the crossing lane L31 is detected during the execution of the notification issuance for information presentation between the right turning vehicle VA and the oncoming vehicle VB by the oncoming vehicle VB being at a distance of equal to or less than the information presentation distance Dth1 from the intersection CS at the first notification issuance timing. In other words, the notification issuance to promote the oncoming vehicle VB to pay attention to the crossing vehicle VC is performed for the oncoming vehicle VB, and the notification issuance to promote the crossing vehicle VC to pay attention to the oncoming vehicle VB is performed for the crossing vehicle VC.

[0176] Furthermore, the notification issuance to promote each of the oncoming vehicle VB and the crossing vehicle VC to pay attention to the intersection entering vehicle at a higher level is performed in a case where the crossing vehicle VC traveling toward the intersection CS in the crossing lane L31 is detected during the notification issuance for alarm by the oncoming vehicle VB being at a distance of equal to or less than the alarm distance Dth2 from the intersection CS at the second notification issuance timing.

[0177] The detection of the crossing vehicle VC can be performed by detecting that the link ID of the lane where the crossing vehicle VC is traveling is the link ID assigned to the crossing lane L31 or by detecting that the lane where the crossing vehicle VC is traveling is the crossing lane L31 from the current position Pc of the crossing vehicle VC, through vehicle-to-vehicle communication or the like.

[0178] On the other hand, the notification issuance to promote each of the crossing vehicle VC and the oncoming vehicle VB to pay attention to the intersection entering vehicle is performed in a case where the oncoming vehicle VB traveling toward the intersection CS in the opposite straight traveling lane L22 is detected during execution of the notification issuance for information presentation between the right turning vehicle VA and the crossing vehicle VC by the crossing vehicle VC being at a distance of equal to or less than the information presentation distance Dth1 from the intersection CS at the first notification issuance timing. In other words, the notification issuance to promote the crossing vehicle VC to pay attention to the oncoming vehicle VB is performed for the crossing vehicle VC, and the notification issuance to promote the oncoming vehicle VB to pay attention to the crossing vehicle VC is performed for the oncoming vehicle VB.

[0179] Furthermore, the notification issuance to promote each of the crossing vehicle VC and the oncoming vehicle VB to pay attention to the intersection entering vehicle at a higher level is performed in a case where the oncoming vehicle VB traveling toward the intersection CS in the opposite straight traveling lane L22 is detected during execution of the notification issuance for alarm by the crossing vehicle VC being at a distance of equal to or less than the alarm distance Dth2 from the intersection CS at the second notification issuance timing.

[0180] Similarly to the above description, the detection of the oncoming vehicle VB can also be performed by detecting that the link ID of the lane where the oncoming vehicle VB is traveling is the link ID assigned to the opposite straight traveling lane L22 or by detecting that the lane where the oncoming vehicle VB is traveling is the opposite straight traveling lane L22 from the current position Pb of the oncoming vehicle VB, through vehicle-to-vehicle communication or the like.

[0181] In this manner, in the situation in which the right turning vehicle VA, the oncoming vehicle VB, and the crossing vehicle VC are traveling toward the intersection CS, the notification issuance to promote each of the oncoming vehicle VB and the crossing vehicle VC to recognize the presence of the intersection entering vehicles VC and VB is performed in a case where vehicles other than the vehicle as a target of notification issuance, in other words, the intersection entering vehicles VC and VB are detected during the execution of the notification issuance between the right turning vehicle VA and the oncoming vehicle VB or the notification issuance between the right turning vehicle VA and the crossing vehicle VC. It is thus possible to prevent circumstances where the driver of the oncoming vehicle VB or the crossing vehicle VC is distracted by the behavior of the right turning vehicle VA, fails to notice the presence of the intersection entering vehicles, and causes contact or collision between the oncoming vehicle VB and the crossing vehicle VC at the intersection CS, and to promote smooth and safe passage of the traffic participants.

[0182] Similarly to the above description, the notification issuance in regard to the intersection entering vehicles can also be performed in a mode in accordance with the mode of the notification issuance performed between the right turning vehicle VA and the oncoming vehicle VB or the crossing vehicle VC in this case as well. In a case where the crossing vehicle VC is detected during execution of the notification issuance for information presentation between the right turning vehicle VA and the oncoming vehicle VB, the notification issuance to promote the crossing vehicle VC to pay attention to the oncoming vehicle VB, which is the intersection entering vehicle, at a low level is performed. On the other hand, in a case where the crossing vehicle VC is detected during execution of the notification issuance for alarm between the right turning vehicle VA and the oncoming vehicle VB, the notification issuance to promote the crossing vehicle VC to pay attention to the oncoming vehicle VB, which is the intersection entering vehicle, at a high level is performed. This makes it possible to alert the oncoming vehicle VB or the crossing vehicle VC in regard to the approach of the counterpart vehicle in an appropriate mode and to promote further safe passage at the intersection CS.

[0183] In the above description, the distance from the outer edge of the predicted collision area ACP, specifically, the intersecting point between the traveling path TRb of the oncoming vehicle VB and the circle (the circles illustrated by the dashed lines in the drawings) defining the outer edge of the predicted collision area ACP to the oncoming vehicle VB is employed as the distance Db from the intersection CS to the oncoming vehicle VB. The distance Db is not limited thereto, and the distance from the predicted collision point CPP to the oncoming vehicle VB may be employed, or the distance along the center line of the opposite lane L22 from the right turning vehicle VA to the oncoming vehicle VB may be employed, as the distance Db.

[0184] Furthermore, although the controllers 101a and 101b included in the right turning vehicle VA and the oncoming vehicle VB, respectively constitute the calculation unit of the notification system 1 and the controllers 101a and 101b constitute one virtual controller, a configuration in which roadside equipment or a remote server is caused to have the road map and a computer program for the notification control and is caused to perform the notification control outside the vehicles may also be adopted. In this case, the right turning vehicle VA and the oncoming vehicle VB transmit position information of the respective vehicles to the external controller through road-to-vehicle communication and receive command signals which are results of calculation related to control. Then, the notification issuance for information presentation or the alarm is executed on the basis of the command signals.

[0185] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.Reference Signs List

[0186] 1 Vehicle notification system; 101a, 101b, 101c Controller; 111a, 111b, 111c Position sensor; 112a, 112b, 112c Vehicle speed sensor; 113a, 113b, 113c Right turn signal switch; 121a, 121b, 121c Communication Device; 131a, 131b, 131c HMI device; VA Right turning vehicle; VB Oncoming vehicle; VC Crossing vehicle.

Claims

1. A vehicle notification system (1) that performs notification issuance for traffic participants including a first vehicle (VA) that is present in a first lane (L11) leading to an intersection (CS), a second vehicle (VB) that travels toward the intersection (VB) in a second lane (L22) opposite to the first lane (L11) and a third vehicle (VC) that travels toward the intersection (CS) in a third lane (L31) intersecting the first lane (L11), the vehicle notification system (1) comprising: a direction-change-intention detection unit (B115a, B115b, B115c) that detects a direction change intention of the first vehicle (VA) while turning right or left at the intersection (CS); a notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) that sets a notification issuance timing in accordance with a relative positional relationship between the first vehicle (VA) and the intersection (CS) after the direction-change-intention detection unit (B115a, B115b, B115c) detects the direction change intention; a first notification issuing unit (B119a, B120a, B119b, B120b) that performs first notification issuance for at least one of the first vehicle (VA) or the second vehicle (VB) under a condition that a first predetermined notification issuance condition defined in relation to a position of the second vehicle (VB) is met at the notification issuance timing set by the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c); a second notification issuing unit (B119a, B120a, B119c, B120c) that performs second notification issuance for at least one of the first vehicle (VA) or the third vehicle (VC) under a condition that a second predetermined notification issuance condition defined in relation to a position of the third vehicle (VC) is met at the notification issuance timing; and a third notification issuing unit (B124b, B124c) that performs third notification issuance to promote at least one of the second vehicle (VB) or the third vehicle (VC) to recognize presence of the other one of the second vehicle (VB) or the third vehicle (VC) in a case where both the first and second predetermined notification issuance conditions are met at the notification issuance timing.

2. The vehicle notification system (1) according to claim 1, further comprising: a determination area setting unit (B122a, B122b, B122c) that sets an intersection area (ACS) that overlaps on a path where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS), wherein the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) sets, as the notification issuance timing, a timing at which or after the first vehicle (VA) arrives at the intersection area (ACS) .

3. The vehicle notification system (1) according to claim 2, wherein the determination area setting unit (B122a, B122b, B122c) regards, as a first predicted collision point (CPP1), a point at which the path where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS) and a path where the second vehicle (VB) travels when the second vehicle (VB) passes the intersection (CS) intersect and sets a first predicted collision area (ACP1) that includes the first predicted collision point (CPP1) in addition to the intersection area (ACS), the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) sets, as the notification issuance timing, a first notification issuance timing and, in a case where the first vehicle (VA) is traveling at a higher vehicle speed than a predetermined vehicle speed toward the first predicted collision point (CPP1) outside the first predicted collision area (ACP1) or is located inside the first predicted collision area (ACP1) after the first notification issuance timing is set, a second notification issuance timing, and the first notification issuing unit (B119a, B120a, B119b, B120b) performs the first notification issuance under the condition that the first predetermined notification issuance condition is met at each of the first and second notification issuance timings and differentiates modes for the first notification issuance for the first notification issuance timing and the second notification issuance timing.

4. The vehicle notification system (1) according to claim 3, wherein the third notification issuing unit (B124b, B124c) differentiates modes for the third notification issuance between a case where the first notification issuing unit (B119a, B120a, B119b, B120b) performs the first notification issuance at the first notification issuance timing and a case where the first notification issuing unit (B119a, B120a, B119b, B120b) performs the first notification issuance at the second notification issuance timing.

5. The vehicle notification system (1) according to claim 2, wherein the determination area setting unit (B122a, B122b, B122c) regards, as a second predicted collision point (CPP2), a point at which the path where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS) and a path where the third vehicle (VC) travels when the third vehicle (VC) passes the intersection (CS) intersect and sets a second predicted collision area (ACP2) that includes the second predicted collision point (CPP2) in addition to the intersection area (ACS), the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) sets, as the notification issuance timing, a first notification issuance timing and, in a case where the third vehicle (VC) is traveling at a higher vehicle speed than a predetermined vehicle speed toward the second predicted collision point (CPP2) outside the second predicted collision area (ACP2) or is located inside the second predicted collision area (ACP2) after the first notification issuance timing is set, a second notification issuance timing, and the second notification issuing unit (B119a, B120a, B119c, B120c) performs the second notification issuance under a condition that the second predetermined notification issuance condition is met at each of the first and second notification issuance timings and differentiates modes for the second notification issuance for the first notification issuance timing and the second notification issuance timing.

6. The vehicle notification system (1) according to claim 5, wherein the third notification issuing unit (B124b, B124c) differentiates modes for the third notification issuance between a case where the second notification issuing unit (B119a, B120a, B119c, B120c) performs the second notification issuance at the first notification issuance timing and a case where the second notification issuing unit (B119a, B120a, B119c, B120c) performs the second notification issuance at the second notification issuance timing.

7. A vehicle notification system (1) that performs notification issuance for traffic participants including a first vehicle (VA) that is present in a first lane (L11) leading to an intersection (CS), an second vehicle (VB) that travels toward the intersection (CS) in a second lane (L22) opposite to the first lane (L11) and a third vehicle (VC) that travels toward the intersection (CS) in a third lane (L31) intersecting the first lane (L11), the vehicle notification system (1) comprising: a direction-change-intention detection unit (B115a, B115b, B115c) that detects a direction change intention of the first vehicle (VA) while turning right or left at the intersection (CS); a notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) that sets a notification issuance timing in accordance with a relative positional relationship between the first vehicle (VA) and the intersection (CS) after the direction-change-intention detection unit (B115a, B115b, B115c) detects the direction change intention; a first notification issuing unit (B119a, B120a, B119b, B120b) that performs first notification issuance for at least one of the first vehicle (VA) or the second vehicle (VB) under a condition that a first predetermined notification issuance condition defined in relation to a position of the second vehicle (VB) is met at the notification issuance timing set by the notification issuance timing setting section (B117a, B118a, B117b, B118b, B117c, B118c); a crossing vehicle detection unit (B123b) that detects presence of the third vehicle (VC) in the third lane (L31); and a third notification issuing unit (B124b) that performs third notification issuance to promote at least one of the second vehicle (VB) or the third vehicle (VC) to recognize presence of the other one of the second vehicle (VB) or the third vehicle (VC) in a case where the crossing vehicle detection unit (B123b) detects the third vehicle (VC) during execution of the first notification issuance by the first notification issuing unit (B119a, B120a, B119b, B120b).

8. The vehicle notification system (1) according to claim 7, Wherein, regarding a point where a path where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS) and a path where the second vehicle (VB) travels when the second vehicle (VB) passes the intersection (CS) intersect as a first predicted collision point (CPP1), the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) sets, as the notification issuance timing, a first notification issuance timing and a second notification issuance timing at which the first vehicle (VA) is located at a position closer to the first predicted collision point (CPP1) than at the first notification issuance timing, after the first notification issuance timing is set, and the first notification issuing unit (B119a, B120a, B119b, B120b) performs the first notification issuance in different modes at each of the first and second notification issuance timings under a condition that the first predetermined notification issuance condition is met.

9. The vehicle notification system (1) according to claim 8, wherein the third notification issuing unit (B124b) differentiates modes for the third notification issuance between a case where the first notification issuing unit (B119a, B120a, B119b, B120b) performs the first notification issuance at the first notification issuance timing and a case where the first notification issuing unit (B119a, B120a, B119b, B120b) performs the first notification issuance at the second notification issuance timing.

10. A vehicle notification system (1) that performs notification issuance for traffic participants including a first vehicle (VA) that is present in a first lane (L11) leading to an intersection (CS), an second vehicle (VB) that travels toward the intersection (CS) in a second lane (L22) opposite to the first lane (L11) and a third vehicle (VC) that travels toward the intersection (VC) in a third lane (L31) intersecting the first lane (L11), the vehicle notification system (1) comprising: a direction-change-intention detection unit (B115a, B115b, B115c) that detects a direction change intention of the first vehicle (VA) while turning right or left at the intersection (CS); a notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) that sets a notification issuance timing in accordance with a relative positional relationship between the first vehicle (VB) and the intersection (CS) after the direction-change-intention detection unit (B115a, B115b, B115c) detects the direction change intention; a second notification issuing unit (B119a, B120a, B119c, B120c) that performs second notification issuance for at least one of the first vehicle (VA) or the third vehicle (VC) under a condition that a second predetermined notification issuance condition defined in relation to a position of the third vehicle (VC) is met at the notification issuance timing set by the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c); an oncoming vehicle detection unit (B123c) that detects presence of the second vehicle (VB) in the second lane (L22); and a third notification issuing unit (B124c) that performs third notification issuance to promote at least one of the third vehicle (VC) or the second vehicle (VB) to recognize presence of the other one of the third vehicle (VC) or the second vehicle (VB) in a case where the oncoming vehicle detection unit (B123c) detects the second vehicle during execution of the second notification issuance by the second notification issuing unit (B119a, B120a, B119c, B120c).

11. The vehicle notification system (1) according to claim 10, Wherein, regarding a point at which a path where the first vehicle (VA) travels when the first vehicle (VA) passes the intersection (CS) and a path where the third vehicle (VC) travels when the third vehicle (VC) passes the intersection (CS) intersect as a second predicted collision point (CPP2), the notification issuance timing setting unit (B117a, B118a, B117b, B118b, B117c, B118c) sets, as the notification issuance timing, a first notification issuance timing and a second notification issuance timing at which the first vehicle (VA) is located at a position closer to the second predicted collision point (CPP2) than at the first notification issuance timing, after the first notification issuance timing is set, and the second notification issuing unit (B119a, B120a, B119c, B120c) performs the second notification issuance in different modes at each of the first and second notification issuance timings under a condition that the second predetermined notification issuance condition is met.

12. The vehicle notification system (1) according to claim 11, wherein the third notification issuing unit (B124c) differentiates modes for the third notification issuance for a case where the second notification issuing unit (B119a, B120a, B119c, B120c) performs the second notification issuance at the first notification issuance timing and a case where the second notification issuing unit (B119a, B120a, B119c, B120c) performs the second notification issuance at the second notification issuance timing.

13. The vehicle notification system (1) according to any one of claims 1 to 12, wherein the intersection (CS) is an intersection (CS) with no traffic lights for regulating passage of the third vehicle (VC).

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