Driving assistance device and driving assistance method

Abstract

To provide a technique advantageous for appropriately performing driving assistance of a self-vehicle.SOLUTION: A driving assistance device includes: a storage section that stores risk position information indicating a risk position where there is a possibility of collision between a self-vehicle and another vehicle; an acquisition section that acquires peripheral vehicle information indicating vehicle speed, a position, a traveling track, and a yaw rate of a peripheral vehicle by vehicle-to-vehicle communication; a prediction section that predicts a possibility of collision on the basis of self-vehicle information indicating vehicle speed, a position, a traveling track, and a yaw rate of the self-vehicle and the peripheral vehicle information; and a notification section that notifies an occupant of the self-vehicle on the basis of a prediction result. When the risk position is not included within a predetermined distance in a traveling direction of the self-vehicle, the prediction section determines a predicted track of the self-vehicle and a predicted track of the peripheral vehicle, and determines an evaluation distance for evaluating an approach situation between the self-vehicle and the peripheral vehicle on the basis of the predicted track of the self-vehicle and the predicted track of the peripheral vehicle. When the evaluation distance is not included in a predetermined range, the prediction section predicts that there is no possibility of collision between the self-vehicle and the peripheral vehicle.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a driving support device and a driving support method.

Background Art

[0002] In recent years, efforts have been actively made to provide access to a sustainable transportation system that takes into account people in vulnerable positions among traffic participants. In order to achieve this, research and development focused on improving traffic safety and convenience even further through research and development on preventive safety technologies. There is known a device that performs driving support for preventing collisions with other vehicles (surrounding vehicles) without using map information. Patent Document 1 discloses a driving support device that registers position information of an intersection where the travel trajectory of the host vehicle intersects with the travel trajectory of another vehicle in a storage unit, and performs driving support for the host vehicle when passing through the intersection again.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Based on the travel trajectory of the host vehicle and the travel trajectory of another vehicle, a driving support device identifies a risk position where the host vehicle may collide with the other vehicle, and this risk position can be used for driving support. However, even if there is actually an intersection in the traveling direction of the host vehicle, driving support using the risk position cannot be executed unless the intersection is identified as a risk position. Some aspects of the present disclosure aim to provide advantageous techniques for appropriately performing driving support for the host vehicle. And, by extension, it contributes to the development of a sustainable transportation system.

Means for Solving the Problems

[0005] According to some embodiments, there is provided a driving assistance device including: a storage means for storing risk position information representing a risk position where the host vehicle equipped with the driving assistance device may collide with another vehicle; an acquisition means for acquiring, by vehicle-to-vehicle communication, information of surrounding vehicles including vehicle speed, position, traveling locus, and yaw rate from surrounding vehicles existing around the host vehicle; a prediction means for predicting a possibility of collision between the host vehicle and the surrounding vehicles based on the host vehicle information representing the vehicle speed, position, traveling locus, and yaw rate of the host vehicle and the information of the surrounding vehicles; and a notification means for notifying an occupant of the host vehicle based on a prediction result by the prediction means. The prediction means determines a predicted locus of the host vehicle based on the host vehicle information when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, determines a predicted locus of the surrounding vehicles based on the information of the surrounding vehicles, determines an evaluation distance for evaluating an approaching situation between the host vehicle and the surrounding vehicles based on the predicted locus of the host vehicle and the predicted locus of the surrounding vehicles, and predicts that there is no possibility of collision between the host vehicle and the surrounding vehicles when the evaluation distance is not included within a predetermined range.

Effect of the Invention

[0006] According to some embodiments, there is provided an advantageous technique for appropriately performing driving assistance of a host vehicle.

Brief Description of the Drawings

[0007]

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MODE FOR CARRYING OUT THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of the features described in the embodiments are essential for the invention. Among the plurality of features described in the embodiments, two or more features may be arbitrarily combined. Also, the same or similar configurations are assigned the same reference numerals, and redundant descriptions are omitted.

[0009] <Example of vehicle configuration> With reference to FIG. 1, an example of the configuration of a vehicle 100 according to some embodiments will be described. As shown in FIG. 1, the vehicle 100 may include a sensor group 101, a turn signal lever 102, a GNSS (Global Navigation Satellite System) antenna 103, a vehicle-to-vehicle communication antenna 104, a notification device 105, a braking device 106, a turn signal 107, and a control device 108. FIG. 1 shows the components referred to in the following description, but the vehicle 100 may include other components for operating as a vehicle, such as a driving device, a transmission, etc. In addition to or instead of this, the vehicle 100 may not include some of the components shown in FIG. 1. The vehicle 100 may be a four-wheeled vehicle, a two-wheeled vehicle, or another type of vehicle. Hereinafter, the driver of the vehicle 100 may sometimes be simply referred to as the driver.

[0010] The control device 108 controls the overall operation of the vehicle 100. As will be described later, the control device 108 executes driving support for the vehicle 100 on which the control device 108 is mounted. Therefore, the control device 108 may be called a driving support device. The driving support provided by the control device 108 may be collision prevention support for preventing (reducing) collisions with other vehicles. In some embodiments, the control device 108 can execute collision prevention support without using map information. In the following description, in order to easily distinguish from other vehicles, the vehicle 100 may be represented as the host vehicle 100. Also, a vehicle different from the vehicle 100 may be represented as another vehicle. Among other vehicles, a vehicle currently present around the host vehicle 100 may be represented as a surrounding vehicle. The surrounding vehicle may be a vehicle that can perform vehicle-to-vehicle communication with the host vehicle 100 at present.

[0011] The sensor group 101 includes various sensors for executing driving support of the vehicle 100. For example, the sensor group 101 may include a speed sensor that detects the speed of the vehicle 100, an acceleration sensor that detects the acceleration of the vehicle 100, and the like. Also, the sensor group 101 may include an external detection sensor such as a camera, a millimeter-wave radar, or a lidar (Light Detection and Ranging) that can detect an object around the vehicle 100. The sensor group 101 may include a sensor for measuring the yaw rate (yaw angle) of the vehicle 100. The sensor group 101 outputs its detection result to the control device 108.

[0012] The turn signal lever 102 is an operator for receiving an operation for changing the indication state of the turn signal 107 (which may also be called a direction indicator) from the driver. The indication state of the turn signal 107 may include a state of indicating the right side of the vehicle 100, a state of indicating the left side of the vehicle 100, and a state of indicating neither side. The control device 108 switches the indication state of the turn signal 107 according to the operation of the turn signal lever 102 by the driver. The turn signal 107 may be located on both the right side and the left side of the vehicle 100. For example, when the driver operates the turn signal lever 102 to indicate the right side, the control device 108 blinks the turn signal 107 on the right side of the vehicle 100. When the driver operates the turn signal lever 102 to indicate the left side, the control device 108 blinks the turn signal 107 on the left side of the vehicle 100. When the driver operates the turn signal lever 102 so as not to indicate any direction, the control device 108 turns off the turn signals 107 on both sides of the vehicle 100. The control device 108 may change the indication state of the turn signal 107 regardless of the operation of the turn signal lever 102 by the driver. For example, the control device 108 may turn off the blinking turn signal 107 in response to the completion of the turning of the vehicle 100.

[0013] The GNSS antenna 103 receives radio waves for position measurement transmitted from GNSS satellites. For example, the GNSS antenna 103 may be used to acquire information regarding the current position and / or the travel locus (travel history) of the vehicle 100. Further, the vehicle-to-vehicle communication antenna 104 is an antenna for transmitting and receiving various data with surrounding vehicles. For example, the vehicle-to-vehicle communication antenna 104 may be used to acquire information regarding the current position, speed, and travel locus of surrounding vehicles.

[0014] The notification device 105 is a device that notifies the passengers (e.g., the driver) of the vehicle 100. When there is a possibility that the vehicle 100 may collide with surrounding vehicles, the control device 108 can, as driving assistance, notify the passengers of the vehicle 100 of the possibility of collision with surrounding vehicles by the notification device 105. The notification device 105 may include a multi-information display (MID) 105a, a head-up display (HUD) 105b, and a speaker 105c. The MID 105a is a display device for displaying visual information directed to the passengers. For example, the MID 105a may display information indicating the possibility of collision with other vehicles. The HUD 105b is a display device for displaying visual information directed to the passengers. For example, the HUD 105b may display information indicating the possibility of collision with other vehicles. The MID 105a and the HUD 105b may be provided at different positions of the vehicle 100. For example, the MID 105a may be provided on the meter panel of the vehicle 100, and the HUD 105b may be provided on the windshield of the vehicle 100. The speaker 105c is an acoustic device for outputting voice information directed to the passengers. For example, the speaker 105c may output a voice or a notification sound indicating the possibility of collision with other vehicles.

[0015] The braking device 106 is a device for performing a braking operation of the vehicle 100, such as a brake. When there is a possibility that the vehicle 100 may collide with surrounding vehicles, the control device 108 can, as driving assistance, perform deceleration assistance of the vehicle 100 by operating the braking device 106 and avoid a collision with surrounding vehicles.

[0016] The control device 108 is a device (computer) that controls the vehicle 100 and may be constituted by, for example, an ECU (Electric Control Unit). The control device 108 can execute driving assistance by vehicle-to-vehicle communication with other vehicles and processing within the vehicle 100. For example, the control device 108 can execute driving assistance without using map information. The control device 108 includes a processing unit 110, a storage unit 111, a GNSS module 113, and a vehicle-to-vehicle communication module 114, and these are connected by a bus (not shown).

[0017] The processing unit 110 is a processor represented by a CPU (Central Processing Unit), and executes programs stored in the storage unit 111. The storage unit 111 includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk, etc., and stores a program (driving support program) for the processing unit 110 to execute driving support processing for the vehicle 100, a program (learning program) for the processing unit 110 to learn risk positions, various data, etc. The storage unit 111 may store risk position information 112 created based on the intersection of the driving trajectory of the vehicle 100 and the driving trajectories of other vehicles. The risk position information 112 may include a plurality of risk positions. The risk position may be a position where the vehicle 100 may collide with other vehicles or a position with a high possibility thereof. The risk position information 112 may be managed as a database.

[0018] The GNSS module 113 receives the position information of the vehicle 100, etc. from GNSS satellites via the GNSS antenna 103. Also, the vehicle-to-vehicle communication module 114 receives various information from other vehicles via the vehicle-to-vehicle communication antenna 104.

[0019] In order to execute driving support (collision prevention support in some embodiments) for the vehicle 100, the processing unit 110 may include an acquisition unit 110a, a prediction unit 110b, a support unit 110c, and an update unit 110d. Note that the processing unit 110 is not limited to a configuration including each of the units 110a to 110d. Depending on the type of driving support executed by the vehicle 100, other units may be added or some units may be omitted.

[0020] The acquisition unit 110a acquires, via the vehicle-to-vehicle communication antenna 104 (vehicle-to-vehicle communication module 114), peripheral vehicle information representing the current position, vehicle speed, driving trajectory, and indicator state of the turn signal of peripheral vehicles existing around the vehicle 100 from the peripheral vehicles. The peripheral vehicle information may explicitly or implicitly represent the current position, vehicle speed, driving trajectory, indicator state of the turn signal, and yaw rate of the peripheral vehicles. For example, the peripheral vehicle information may include the vehicle speed as it is, or may include information for calculating the vehicle speed (the current and the two previous geographical positions and their positioning times). Also, the peripheral vehicle information may include the yaw rate as it is, or may include information for calculating the yaw rate (the traveling directions of the peripheral vehicles at present and immediately before). The acquisition unit 110a may acquire own vehicle information representing the current position, speed, driving trajectory, indicator state of the turn signal 107, and yaw rate of the vehicle 100 via the sensor group 101 and the GNSS antenna 103 (GNSS module 113). The acquisition unit 110a may acquire the indicator state of the turn signal 107 from the turn signal 107, or may store the most recent change command to the turn signal 107 and acquire the indicator state based on the stored change command.

[0021] The prediction unit 110b predicts the possibility of the vehicle 100 colliding with other vehicles based on the own vehicle information and the peripheral vehicle information acquired by the acquisition unit 110a. The prediction unit 110b may set a determination area and predict the possibility of the vehicle 100 colliding with other vehicles in the determination area. Also, the prediction unit 110b may perform driving support for the vehicle 100 based on the risk position information 112. For example, when at least one of the plurality of risk positions included in the risk position information 112 is located near the own vehicle, the prediction unit 110b may set the determination area to include the risk position.

[0022] Based on the prediction result by the prediction unit 110b, the support unit 110c performs driving support (collision prevention support) for the host vehicle 100. In some embodiments, the support unit 110c can execute at least one of notification to the passengers of the vehicle 100 by the notification device 105 and deceleration support for the vehicle 100 by the braking device 106 as driving support for the vehicle 100. The deceleration support may support decelerating until the host vehicle 100 stops, that is, may include stop support. The stop support may include not only deceleration of the host vehicle 100, but also determination of the stop position of the host vehicle 100, route planning toward the stop position, and automatic steering along the route.

[0023] The update unit 110d identifies an intersection of the travel trajectory of the vehicle 100 and the travel trajectories of surrounding vehicles. The intersection of the travel trajectory of the vehicle 100 and the travel trajectories of surrounding vehicles is hereinafter referred to as a trajectory intersection. There may be a road intersection near the trajectory intersection. Further, the update unit 110d updates the risk position information 112 stored in the storage unit 111 based on the identified trajectory intersection. For example, the update unit 110d may update the risk position information 112 by adding the trajectory intersection to the risk position information 112. Instead of or in addition to this, the update unit 110d may update the risk position information 112 by correcting any risk position included in the risk position information 112 based on the trajectory intersection.

[0024] Subsequently, with reference to FIG. 2, an example of the risk position information 112 will be described. In the example of FIG. 2, the risk position information 112 is described in a table format, but the risk position information 112 may be in other formats. The risk position information 112 has a record for each risk position. The columns of the risk position information 112 shown in FIG. 2 are an example. The risk position information 112 may include other columns or may not include some of the columns shown in FIG. 2.

[0025] The risk position information 112 may include information regarding the risk position ID, registration date and time, coordinates, and passing direction for each risk position. The risk position ID is a number that uniquely identifies the risk position. The registration date and time is the date and time when the risk position was registered in the risk position information 112. The coordinates are data for specifying the risk position and are represented, for example, by data of latitude and longitude. The coordinates may include altitude data such as elevation in addition to the latitude and longitude data. The passing direction is the direction (orientation, angle) in which the vehicle 100 was facing at the time of passing through the trajectory intersection used to determine the risk position. The passing direction may be understood as the traveling direction (entry direction) of the vehicle 100 when entering the trajectory intersection. In the example of FIG. 2, the passing direction of the vehicle 100 is defined with the north direction being 0°, the east direction being 90°, the south direction being 180°, and the west direction being 270°.

[0026] The intersection angle is the intersection angle between the traveling trajectory of the host vehicle 100 and the traveling trajectory of another vehicle at the trajectory intersection used to determine the risk position. The intersection angle may be the rotation angle of the traveling direction vector of the other vehicle at the trajectory intersection with respect to the traveling direction vector of the host vehicle 100 at the trajectory intersection. In this case, the intersection angle represents from which direction the other vehicle intersects with respect to the traveling trajectory of the host vehicle. The other vehicle trajectory is the traveling trajectory of another vehicle passing through the trajectory intersection used to determine the risk position.

[0027] Next, with reference to FIG. 3, an example of a trajectory intersection will be described. As described above, a trajectory intersection is an intersection of the traveling trajectory of vehicle 100 and the traveling trajectory of another vehicle. In this specification, a case where vehicle 100 is located in an area where right-hand traffic is obligatory will be described. In this case, among the left side and the right side, the side of the road where traffic is obligatory in the area where vehicle 100 is located is the right side, and the opposite side is the left side. Also, the oncoming lane side of vehicle 100 is the left side of vehicle 100. The embodiments described in this specification are also applicable when vehicle 100 is located in an area where left-hand traffic is obligatory. In this case, the left and right in the processes described below (for example, the right and left turns of vehicle 100 and other vehicles, and the right and left of the indicating state of the turn signal) are interchanged. Specifically, among the left side and the right side, the side of the road where traffic is obligatory in the area where vehicle 100 is located is the left side, and the opposite side is the right side. Also, the oncoming lane side of vehicle 100 is the right side of vehicle 100.

[0028] In the example shown in FIG. 3(a), the position where the traveling trajectory 301a of the host vehicle 100 going straight north and the traveling trajectory 302a of another vehicle OVa going straight west intersect is the trajectory intersection CPa. Note that since the timing (time) when the host vehicle 100 passes through the trajectory intersection CPa and the timing (time) when the other vehicle OVa passes through the trajectory intersection CPa are different from each other, no collision has occurred between the host vehicle 100 and the other vehicle OVa. Also, the traveling trajectory 301a of the host vehicle 100 is included in the host vehicle information acquired by the acquisition unit 110a via the sensor group 101 and the GNSS antenna 103 (GNSS module 113). The traveling trajectory 302a of the other vehicle OVa is included in the other vehicle information acquired by the acquisition unit 110a via the vehicle-to-vehicle communication antenna 104 (vehicle-to-vehicle communication module 114). Since the other vehicle OVa is a surrounding vehicle existing around the host vehicle 100 at the time of acquisition, the other vehicle information may be understood as surrounding vehicle information.

[0029] In the example shown in FIG. 3(b), the position where the travel trajectory 301b of the host vehicle 100 that travels straight north and then turns left intersects with the travel trajectory 302b of the other vehicle OVb that travels straight south becomes the trajectory intersection point CPb. Note that since the timing (time) at which the host vehicle 100 passes through the trajectory intersection point CPb and the timing (time) at which the other vehicle OVb passes through the trajectory intersection point CPb are different from each other, no collision occurs between the host vehicle 100 and the other vehicle OVb. Further, the travel trajectory 301b of the host vehicle 100 is included in the host vehicle information acquired by the acquisition unit 110a via the sensor group 101 and the GNSS antenna 103 (GNSS module 113), similar to the travel trajectory 301a. The travel trajectory 302b of the other vehicle OVb is included in the other vehicle information (surrounding vehicle information) acquired by the acquisition unit 110a via the vehicle-to-vehicle communication antenna 104 (vehicle-to-vehicle communication module 114), similar to the travel trajectory 302a.

[0030] The functions of the control device 108 can be realized by either hardware or software. For example, the functions of the control device 108 may be realized by the processing unit 110 (CPU) executing the driving support program and / or the learning program as described above, or may be realized by an integrated circuit such as a PLD (Programmable Logic Device) or an ASIC (Application Specific Integrated Circuit). Further, in the example of FIG. 1, the control device 108 is shown as a single element, but it may be divided into two or more elements as necessary.

[0031] <Management Process of Surrounding Vehicles> With reference to FIG. 4, an example of the process for managing surrounding vehicles will be described. The process shown in the flowchart of FIG. 4 is executed by the processing unit 110 according to the learning program read from the storage unit 111. The process of FIG. 4 may be started, for example, in response to the ignition of the vehicle 100 being turned on. The process of FIG. 4 can be repeatedly executed until the ignition of the vehicle 100 is turned off.

[0032] In step S401, the processing unit 110 (for example, its acquisition unit 110a) determines whether there are other vehicles around the host vehicle 100. When the processing unit 110 determines that there are other vehicles around the host vehicle 100, the process transitions to step S402, and in other cases, the process transitions to step S404. For example, when vehicle-to-vehicle communication can be performed via the vehicle-to-vehicle communication antenna 104 (vehicle-to-vehicle communication module 114), the processing unit 110 may determine that there are other vehicles around the host vehicle 100.

[0033] In step S402, the processing unit 110 (for example, its acquisition unit 110a) registers the other vehicle discovered in step S401 as a surrounding vehicle. For example, the storage unit 111 may store a list of surrounding vehicles, and the processing unit 110 may add the information of the discovered surrounding vehicle to this list. As will be described later, the surrounding vehicle is a target for determining the possibility of collision. Instead of managing the information of the surrounding vehicles in a list, in a repeatedly executed process, information may be acquired from all other vehicles capable of vehicle-to-vehicle communication at the start of each cycle, and the information acquired in this cycle may be discarded at the end of each cycle.

[0034] In step S403, the processing unit 110 (for example, its acquisition unit 110a) starts acquiring surrounding vehicle information by vehicle-to-vehicle communication from the surrounding vehicles. As described above, the surrounding vehicle information may represent the vehicle speed, position, and driving trajectory of the surrounding vehicle. After starting to acquire the surrounding vehicle information in step S402, the processing unit 110 repeatedly acquires the surrounding vehicle information periodically (for example, every 100 milliseconds) until vehicle-to-vehicle communication with the surrounding vehicles becomes impossible.

[0035] After the start of acquisition of surrounding vehicle information, in step S403, the processing unit 110 (for example, its acquisition unit 110a) determines whether there is a vehicle for which vehicle-to-vehicle communication has become impossible among one or more registered surrounding vehicles. When there is such a vehicle, the processing unit 110 transitions the process to step S405, and when there is no such vehicle, the processing unit 110 transitions the process to step S401. For example, when a surrounding vehicle goes out of the communication range of vehicle-to-vehicle communication or the power supply of the surrounding vehicle is turned off, the vehicle 100 cannot perform vehicle-to-vehicle communication with the surrounding vehicle.

[0036] In step S405, the processing unit 110 (for example, its acquisition unit 110a) cancels the registration of the surrounding vehicle for which vehicle-to-vehicle communication has become impossible. In other words, the processing unit 110 does not treat the vehicle for which vehicle-to-vehicle communication has become impossible as a surrounding vehicle. For example, the processing unit 110 deletes the information of the surrounding vehicle for which vehicle-to-vehicle communication has become impossible from the list of surrounding vehicles stored in the storage unit 111.

[0037] As described above, by executing the process of FIG. 4, the processing unit 110 can periodically acquire the latest surrounding vehicle information from other vehicles (i.e., surrounding vehicles) around the host vehicle 100.

[0038] <Driving support process> With reference to FIGS. 6 to 18, the driving support process of some embodiments will be described. As described with reference to FIG. 3(a), when another vehicle is included in the lateral range of the host vehicle 100, if both the host vehicle 100 and the other vehicle go straight, there is a possibility that these vehicles will collide. On the other hand, as described with reference to FIG. 3(b), when another vehicle is included in the front range of the host vehicle 100, if the host vehicle 100 turns left and the other vehicle goes straight, there is a possibility that these vehicles will collide. Thus, depending on the position of the other vehicle relative to the host vehicle 100, the situations in which these vehicles may collide can be different. Therefore, in some embodiments, the control device 108 performs different driving supports according to whether a surrounding vehicle exists within the front range or the lateral range with respect to the host vehicle 100.

[0039] Referring to FIG. 5, the driving support process of some embodiments will be described. The driving support process shown in the flowchart of FIG. 5 may be performed by the processing unit 110 executing the driving support program read from the storage unit 111 in the control device 108. The process of FIG. 4 may be started, for example, in response to the driving support setting being turned on. The process of FIG. 4 can be repeatedly executed until the driving support setting is turned off or the ignition of the vehicle 100 is turned off.

[0040] In step S501, the processing unit 110 (for example, its support unit 110c) refers to the risk position information 112 stored in the storage unit 111 to determine whether there is a risk position within a predetermined distance (for example, 100 m) in the traveling direction of the host vehicle 100. For example, the processing unit 110 can determine whether there is a risk position within the predetermined distance by comparing the current position of the vehicle 100 acquired by the acquisition unit 110a via the GNSS antenna 103 (GNSS module 113) with the coordinates (latitude, longitude) of each risk position included in the risk position information 112.

[0041] If there is a risk position within a predetermined distance (for example, 100 m) in the traveling direction of the host vehicle 100, the processing unit 110 transfers the process to step S502, and if there is no risk position within the predetermined distance, the processing unit 110 transfers the process to step S503. In step S502, the processing unit 110 determines whether to perform driving support using the risk positions included within the predetermined distance. Details of this process will be described later. In step S503, the processing unit 110 determines whether to perform driving support without using the risk positions. Details of this process will be described later.

[0042] Referring to FIG. 6, a range for selecting a driving assistance method when there is no risk position within a predetermined distance in the traveling direction of the host vehicle 100 will be described. Range 600 is located in front of vehicle 100. The front of vehicle 100 may be a range including the front face of vehicle 100. As shown in FIG. 6, range 600 may be a fan-shaped range or may have other shapes. The fan-shaped range may be defined by a predetermined distance and a predetermined angle. The predetermined distance may be, for example, 800 m or more and 1000 m or less, for example, 900 m. The same applies to the predetermined distance of the following fan-shaped ranges. Range 600 may be symmetric with respect to the direction of the front face of vehicle 100. The central angle of range 600 may be, for example, about 100 degrees to 110 degrees.

[0043] Range 601 is located on the side of vehicle 100. The side of vehicle 100 may be a range including the diagonally forward of vehicle 100. Range 601 may include the directly lateral direction of vehicle 100. As shown in FIG. 6, range 601 may be a fan-shaped range or may have other shapes. The fan-shaped range may be defined by a predetermined distance and a predetermined angle. In the example of FIG. 6, range 601 is located on each of the right side and the left side of vehicle 100. The central angle of range 601 may be, for example, about 80 degrees to 90 degrees.

[0044] In the example of FIG. 6, a part of range 600 and a part of range 601 overlap. The central angle of this overlapping part may be, for example, about 10 degrees to 20 degrees. When a surrounding vehicle exists in this overlapping part, this surrounding vehicle is an object of both the driving assistance in the situation of FIG. 3(a) and the driving assistance in the situation of FIG. 3(b). Instead of the example of FIG. 6, range 600 and range 601 may only be in contact with each other or may be separated from each other. Range 600, the range 601 on the right side of vehicle 100, and the range 601 on the left side of vehicle 100 may all be the same size or at least a part may have different sizes.

[0045] When a surrounding vehicle is included in range 601, as shown in Fig. 3(a), the control device 108 may collide with another vehicle if the host vehicle 100 travels straight. Therefore, the control device 108 predicts the possibility of a collision caused by the host vehicle 100 traveling straight. This operation will be described later with reference to Figs. 7 to 12. On the other hand, when a surrounding vehicle is included in range 600, as shown in Fig. 3(b), the control device 108 may collide with another vehicle if the host vehicle 100 turns left. Therefore, the control device 108 predicts the possibility of a collision caused by the host vehicle 100 traveling straight. This operation will be described later with reference to Figs. 13 to 16. The positions of ranges 600 and 601 relative to the host vehicle 100 may be set in advance (e.g., at the time of manufacture of vehicle 100 or at the time of software update) and stored in the storage unit 111.

[0046] Fig. 7 illustrates an example of a process for performing driving assistance when a surrounding vehicle RV (Fig. 10(a)) exists within range 601 on the side of the host vehicle 100 in step S503 (i.e., the process when no risk position is included within a predetermined distance in the traveling direction of the host vehicle 100). The process shown in the flowchart of Fig. 7 is executed by the processing unit 110 according to a driving assistance program read from the storage unit 111. The process of Fig. 7 may be executed for each surrounding vehicle RV each time a surrounding vehicle RV is newly registered in step S702 of Fig. 7, for example, while the driving assistance setting is on. In the process of Fig. 7, a plurality of other vehicles may be registered as surrounding vehicles. The process of Fig. 7 is executed for each of these plurality of surrounding vehicles.

[0047] In step S701, the processing unit 110 (for example, its prediction unit 110b) determines whether the surrounding vehicle RV exists within the range 601 on the side of the host vehicle 100. When it is determined that the surrounding vehicle RV exists within the range 601 on the side of the host vehicle 100, the processing unit 110 transitions the process to step S702, and repeats step S701 in other cases. This determination may be made based on the current position of the surrounding vehicle RV included in the latest surrounding vehicle information acquired from the surrounding vehicle RV. In the example shown in FIG. 11(a), the surrounding vehicle RV exists within the range 601.

[0048] In step S702, the processing unit 110 (for example, its prediction unit 110b) determines whether the predicted travel path of the host vehicle 100 and the predicted travel path of the surrounding vehicle RV intersect. When it is determined that the travel paths of these two predicted vehicles intersect, the processing unit 110 transitions the process to step S703, and repeats step S702 in other cases. When it is determined that the predicted travel path of the host vehicle 100 and the predicted travel path of the surrounding vehicle RV intersect, the processing unit 110 specifies the coordinates of the predicted intersection point.

[0049] With reference to FIG. 8, a specific example of the process in step S702 will be described. In step S801, the processing unit 110 determines the predicted trajectory of the host vehicle 100 and the prediction accuracy of this predicted trajectory. Then, the processing unit 110 determines whether the prediction accuracy of the predicted trajectory of the host vehicle 100 is equal to or higher than a threshold accuracy. When it is determined that the prediction accuracy of the predicted trajectory of the host vehicle 100 is equal to or higher than the threshold accuracy, the processing unit 110 transitions the process to step S802, and when it is determined that the prediction accuracy of the predicted trajectory of the host vehicle 100 is less than the threshold accuracy, the processing unit 110 transitions the process to step S805.

[0050] The processing unit 110 may determine the predicted trajectory of the host vehicle 100 based on the host vehicle information. For example, the processing unit 110 may calculate the current radius of curvature based on the yaw rate included in the host vehicle information, and determine an arc having this radius of curvature as the predicted trajectory.

[0051] The processing unit 110 may determine the prediction accuracy of the predicted trajectory of the host vehicle 100 based on the current vehicle speed of the host vehicle 100 and the current yaw rate of the host vehicle 100. For example, the processing unit 110 may determine that the smaller the yaw angular acceleration of the host vehicle 100, the higher the prediction accuracy of the predicted trajectory. The processing unit 110 may calculate the yaw angular acceleration by differentiating the yaw rate with respect to time. For example, the processing unit 110 may determine the reliability of the prediction of the predicted trajectory by referring to the correspondence table 900 shown in FIG. 9. The correspondence table 900 shows the correspondence relationship between the yaw angular acceleration and the reliability. The correspondence table 900 may be set in advance (for example, at the time of manufacturing the vehicle 100 or at the time of software update) and stored in the storage unit 111. In the correspondence table 900, the reliability of the prediction of the predicted trajectory is classified into 11 levels, and the higher the reliability, the higher the prediction accuracy of the predicted trajectory. For example, when the yaw angular acceleration is 2 1.5° / s 2 or more and less than 2° / s, the processing unit 110 determines that the reliability of the prediction of the predicted trajectory is 70%.

[0052] Generally, at low vehicle speeds, the measurement accuracy of the radius of curvature of the host vehicle 100 is low. Therefore, the processing unit 110 may determine that the higher the vehicle speed of the host vehicle 100, the higher the prediction accuracy of the predicted trajectory. For example, the processing unit 110 may classify the reliability of the prediction of the predicted trajectory into two levels. The processing unit 110 may determine that the reliability is high when the vehicle speed of the host vehicle 100 is equal to or higher than a threshold vehicle speed (for example, 20 km / h), and may determine that the reliability is low when the vehicle speed of the host vehicle 100 is less than the threshold vehicle speed.

[0053] The processing unit 110 may combine the determination based on the yaw angular acceleration and the determination based on the vehicle speed. For example, when the reliability determined based on the yaw angular acceleration is equal to or higher than a threshold reliability (for example, 70%) and the vehicle speed is equal to or higher than a threshold vehicle speed (for example, 20 km / h), the processing unit 110 determines that the prediction accuracy of the predicted trajectory of the host vehicle 100 is equal to or higher than a threshold accuracy, and in other cases, determines that the prediction accuracy of the predicted trajectory of the host vehicle 100 is less than the threshold accuracy.

[0054] In step S802, the processing unit 110 determines the current radius of curvature of the host vehicle 100. Then, the processing unit 110 determines whether the radius of curvature of the host vehicle 100 is greater than or equal to a threshold radius (for example, 3000 m). If it is determined that the radius of curvature of the host vehicle 100 is greater than or equal to the threshold radius, the processing transitions to step S803. If it is determined that the radius of curvature of the host vehicle 100 is less than the threshold radius, the processing transitions to step S804.

[0055] In step S803, the processing unit 110 determines an intersection point between the straight - ahead trajectory of the host vehicle 100 and the straight - ahead trajectory of the surrounding vehicle RV as a predicted intersection point. The straight - ahead trajectory is the trajectory when it is assumed that the host vehicle 100 travels straight ahead. The processing of step S803 is executed when it is determined that the radius of curvature of the host vehicle 100 is greater than or equal to a threshold radius (for example, 3000 m). In this case, the occupant of the host vehicle 100 is considered to intend to drive the host vehicle 100 straight ahead. Therefore, the processing unit 110 determines the predicted intersection point using the straight - ahead trajectory of the host vehicle 100. Referring to FIG. 10(a), an example of the predicted intersection point in step S803 will be described. In this example, the intersection point between the straight - ahead trajectory 1000 of the host vehicle 100 and the straight - ahead trajectory 1001 of the surrounding vehicle RV is determined as the predicted intersection point 1002.

[0056] In step S804, the processing unit 110 determines an intersection point between the predicted trajectory of the host vehicle 100 and the straight - ahead trajectory of the surrounding vehicle RV as a predicted intersection point. The processing unit 110 may use the predicted trajectory determined in step S801. The processing of step S804 is executed when it is determined that the radius of curvature of the host vehicle 100 is less than a threshold radius (for example, 3000 m). In this case, the occupant of the host vehicle 100 is considered to intend to turn the host vehicle 100. Therefore, the processing unit 110 determines the predicted intersection point using the predicted trajectory of the host vehicle 100. Referring to FIG. 10(b), an example of the predicted intersection point in step S804 will be described. In this example, the intersection point between the predicted trajectory 1010 of the host vehicle 100 and the straight - ahead trajectory 1011 of the surrounding vehicle RV is determined as the predicted intersection point 1012. The predicted trajectory 1010 may be an arc having the determined radius of curvature.

[0057] In step S805, the processing unit 110 determines the predicted trajectory of the surrounding vehicle RV and the prediction accuracy of this predicted trajectory. Then, the processing unit 110 determines whether the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is equal to or higher than a threshold accuracy. When it is determined that the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is equal to or higher than the threshold accuracy, the processing unit 110 transitions the process to step S806, and when it is determined that the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is less than the threshold accuracy, the processing unit 110 transitions the process to step S809.

[0058] The processing unit 110 may determine the predicted trajectory of the surrounding vehicle RV based on the surrounding vehicle information. For example, the processing unit 110 may calculate the current radius of curvature based on the yaw rate included in the surrounding vehicle information and determine an arc having this radius of curvature as the predicted trajectory.

[0059] The processing unit 110 may determine the prediction accuracy of the predicted trajectory of the surrounding vehicle RV based on the current vehicle speed of the surrounding vehicle RV and the current yaw rate of the surrounding vehicle RV. Since the method for determining the prediction accuracy of the predicted trajectory of the surrounding vehicle RV may be the same as the method for determining the prediction accuracy of the predicted trajectory of the host vehicle 100 described above, duplicate explanations are omitted.

[0060] In step S806, the processing unit 110 determines the current radius of curvature of the surrounding vehicle RV. Then, the processing unit 110 determines whether the radius of curvature of the surrounding vehicle RV is equal to or greater than a threshold radius. When it is determined that the radius of curvature of the surrounding vehicle RV is equal to or greater than the threshold radius (for example, 3000 m), the processing unit 110 transitions the process to step S807, and when it is determined that the radius of curvature of the surrounding vehicle RV is less than the threshold radius, the processing unit 110 transitions the process to step S808.

[0061] In step S807, the processing unit 110 determines the intersection of the straight - line trajectory of the host vehicle 100 and the straight - line trajectory of the surrounding vehicle RV as the predicted intersection. Since the method for determining the predicted intersection in step S807 may be the same as the method for determining the predicted intersection in step S803, duplicate explanations are omitted.

[0062] In step S808, the processing unit 110 determines the intersection point between the straight-line trajectory of the host vehicle 100 and the predicted trajectory of the surrounding vehicle RV as the predicted intersection point. The processing unit 110 may use the predicted trajectory determined in step S805. The processing in step S808 is executed when it is determined that the radius of curvature of the surrounding vehicle RV is less than the threshold radius (for example, 3000 m). In this case, it is considered that the occupant of the surrounding vehicle RV intends to turn the surrounding vehicle RV. Therefore, the processing unit 110 determines the predicted intersection point using the predicted trajectory of the surrounding vehicle RV. Referring to FIG. 10(c), an example of the predicted intersection point in step S808 will be described. In this example, the intersection point between the straight-ahead trajectory 1020 of the host vehicle 100 and the predicted trajectory 1021 of the surrounding vehicle RV is determined as the predicted intersection point 1022. The predicted trajectory 1021 may be an arc having the determined radius of curvature.

[0063] After determining the predicted intersection point in step S803, step S804, step S807, or step S808, the processing unit 110 determines, in step S809, an evaluation distance based on the predicted intersection point and the current position of the host vehicle 100. The evaluation distance may be a distance for evaluating the approaching situation between the host vehicle 100 and the surrounding vehicle RV. According to the method of FIG. 8 in this way, the processing unit 110 determines an evaluation distance for evaluating the approaching situation between the host vehicle 100 and the surrounding vehicle RV based on the predicted trajectory of the host vehicle 100 and the predicted trajectory of the surrounding vehicle RV. Further, the processing unit 110 selects a method for determining the evaluation distance from a plurality of candidate determination methods based on the prediction accuracy of the predicted trajectory of the host vehicle 100, the radius of curvature of the predicted trajectory of the host vehicle 100, the prediction accuracy of the predicted trajectory of the surrounding vehicle RV, and the radius of curvature of the predicted trajectory of the surrounding vehicle RV.

[0064] Referring to FIG. 10 again, the evaluation distance will be described. As shown in FIG. 10(a), when the predicted intersection point 1002 is on the straight-ahead trajectory 1000 of the host vehicle 100, the processing unit 110 may determine the distance 1003 between the host vehicle 100 and the predicted intersection point 1002 as the evaluation distance. Similarly for FIG. 10(c), the processing unit 110 may determine the distance 1023 between the host vehicle 100 and the predicted intersection point 1022 as the evaluation distance.

[0065] As shown in FIG. 10(b), when the predicted intersection 1012 is not on the straight - ahead trajectory of the host vehicle 100, the processing unit 110 may determine the distance 1013 between the host vehicle 100 and the predicted intersection 1012 as the evaluation distance. Alternatively, the processing unit 110 may determine the straight - line distance between a plane passing through a part (e.g., the center) of the host vehicle 100 and having the traveling direction as the normal line and the predicted intersection 1012 as the evaluation distance. Alternatively, the processing unit 110 may determine the distance on the predicted trajectory 1010 between the host vehicle 100 and the predicted intersection 1012 as the evaluation distance.

[0066] In step S810, the processing unit 110 determines whether the evaluation distance determined in step S809 is included in a predetermined range (e.g., 100 m). When it is determined that the evaluation distance is included in the predetermined range (e.g., 100 m), the processing unit 110 transfers the process to step S811, and when it is determined that the evaluation distance is not included in the predetermined range, the processing unit 110 transfers the process to step S812.

[0067] In step S811, the processing unit 110 determines that there is no possibility of collision. When step S811 is executed, after the processing of FIG. 8 is completed, the processing unit 110 transfers the process to step S707 of FIG. 7. In step S812, the processing unit 110 determines that there is a possibility of collision. When step S812 is executed, after the processing of FIG. 8 is completed, the processing unit 110 transfers the process to step S703 of FIG. 7. The determination result that there is a possibility of collision may be changed in subsequent processing (e.g., step S704 of FIG. 7).

[0068] When it is determined that the prediction accuracy of the predicted trajectory of the host vehicle 100 is less than the threshold accuracy and the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is less than the threshold accuracy, in step S811, the processing unit 110 may predict that there is no possibility of collision between the host vehicle 100 and the surrounding vehicle RV. When the prediction accuracy of the predicted trajectory of each of the host vehicle 100 and the surrounding vehicle RV is low, there is a possibility that driving support (for example, notification to the occupant) may be performed even though the two vehicles are not in a situation of approaching each other. Therefore, in such a case, by predicting that there is no possibility of collision and suppressing the driving support (for example, notification to the occupant), it is possible to suppress the occupant from feeling bothered.

[0069] In the method of FIG. 10 described above, in steps S803 and S804, the processing unit 110 determines the predicted intersection using the straight-ahead trajectory of the surrounding vehicle RV. Instead of this, in steps S803 and S804, when it is determined that the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is equal to or higher than the threshold accuracy and the radius of curvature of the surrounding vehicle RV is less than the threshold radius, the processing unit 110 may determine the predicted intersection using the predicted trajectory of the surrounding vehicle RV.

[0070] Returning to the description of FIG. 7, in step S703, the processing unit 110 (for example, its prediction unit 110b) sets a determination area with the predicted intersection determined by the method of FIG. 8 as a reference position, and stores the determination area in the storage unit 111. The determination area may be an area where the prediction of the possibility of collision is made. Referring to FIG. 11(a), an example of the determination area 1103 set with the predicted intersection 1102 as a reference position will be described. In the example shown in FIG. 11(a), similar to FIG. 10(a), the intersection of the straight-ahead trajectory 1100 of the host vehicle 100 and the straight-ahead trajectory 1101 of the surrounding vehicle RV is determined as the predicted intersection 1102. Instead of this, the description of FIG. 11 is also applicable to the cases of FIGS. 10(b) or 10(c).

[0071] The determination area 1103 may be a rectangle that includes the predicted intersection 1102 and has sides parallel to the straight - ahead trajectory 1100 of the host vehicle 100. Alternatively, the determination area 1103 may have other shapes. The position and shape of the determination area 1103 with respect to the predicted intersection 1102 may be set in advance (for example, at the time of manufacturing the vehicle 100 or when software is updated) and stored in the storage unit 111. The processing unit 110 may expand the determination area 1103 to include the risk position when a risk position exists near the determination area 1103.

[0072] As shown in FIG. 11(a), when the surrounding vehicle RV is on the right side of the host vehicle 100 (i.e., the side opposite to the oncoming - lane side), and as shown in FIG. 11(b), when the surrounding vehicle RV is on the left side of the host vehicle 100 (i.e., the oncoming - lane side), the processing unit 110 may set determination areas 1103 with different shapes (sizes). Whether the surrounding vehicle RV is on the right side or the left side of the host vehicle 100, the vehicle - width - direction length 1104 of the determination area 1103 may be the same length (for example, a length equivalent to one lane, which is 3 m to 4 m). The vehicle - length - direction length 1105 of the determination area 1103 when the surrounding vehicle RV is on the right side of the host vehicle 100 may be longer than the vehicle - length - direction length 1105 of the determination area 1103 when the surrounding vehicle RV is on the left side of the host vehicle 100. The vehicle - length - direction length 1105 of the determination area 1103 when the surrounding vehicle RV is on the right side of the host vehicle 100 may be, for example, a length equivalent to three lanes, which is 9 m to 11 m. The vehicle - length - direction length 1105 of the determination area 1103 when the surrounding vehicle RV is on the left side of the host vehicle 100 may be, for example, a length equivalent to two lanes, which is 6 m to 8 m.

[0073] Whether the surrounding vehicle RV is on the right or left side of the host vehicle 100, the distance between the side of the determination area 1103 that is far from the host vehicle 100 and the predicted intersection 1102 may be the same (for example, about 1.5 m corresponding to half a lane). As a result, the length 1106 of the portion of the determination area 1103 that is closer to the host vehicle 100 than the predicted intersection 1102 when the surrounding vehicle RV is on the right side of the host vehicle 100 is greater than the length 1106 of the portion of the determination area 1103 that is closer to the host vehicle 100 than the predicted intersection 1102 when the surrounding vehicle RV is on the left side of the host vehicle 100. When the surrounding vehicle RV is on the right side of the host vehicle 100, there may be a possibility that the oncoming lane of the lane in which the surrounding vehicle RV is traveling exists between the predicted intersection 1102 and the host vehicle 100. Therefore, by expanding the determination area 1103 toward the host vehicle 100, it is possible to suppress a collision with another vehicle (which may not have a vehicle-to-vehicle communication function) traveling in this oncoming lane.

[0074] In step S704, the processing unit 110 (for example, its prediction unit 110b) predicts the possibility of a collision between the host vehicle 100 and the surrounding vehicle RV in the determination area 1103. When it is predicted that there is a possibility of a collision between the host vehicle 100 and the surrounding vehicle RV, the processing unit 110 transitions the process to step S705, and in other cases, transitions the process to step S707.

[0075] The possibility of collision may be determined based on the predicted time until the surrounding vehicle RV reaches the predicted intersection 1102 (hereinafter simply referred to as "arrival time"). This arrival time may be calculated based on, for example, the latest surrounding vehicle information acquired from the surrounding vehicle RV. For example, the processing unit 110 can predict the predicted time of the surrounding vehicle RV to the predicted intersection 1102 by dividing the distance between the surrounding vehicle RV and the predicted intersection 1102 by the speed of the surrounding vehicle RV.

[0076] The processing unit 110 may predict that there is a possibility of collision when this arrival time is equal to or less than the threshold time, and determine that there is no possibility of collision when this arrival time is greater than the threshold time. The threshold time may be settable by the occupant of the host vehicle 100.

[0077] The processing unit 110 may change the threshold time according to the speed of the surrounding vehicle RV. FIG. 12 is a diagram showing the relationship between the speed of the surrounding vehicle RV and the stop time of the surrounding vehicle RV. The stop time of the surrounding vehicle RV is the time until the surrounding vehicle RV stops at a deceleration (e.g., 0.4G) by a general braking operation. In FIG. 12, a specified range (speed upper limit value, speed lower limit value) regarding the speed of the surrounding vehicle RV and a time upper limit value and a time lower limit value regarding the collision margin time (TTC) are shown. The specified range is the speed range of the surrounding vehicle RV in which the driving support of the host vehicle 100 is performed. The time upper limit value is the upper limit value of the collision margin time arbitrarily set by the driver or the like, and the time lower limit value is the lower limit value of the collision margin time set from the measurement position accuracy of GNSS.

[0078] The processing unit 110 sets the stop time corresponding to the speed of the surrounding vehicle RV as the threshold time based on the "relationship between the speed and the stop time of the surrounding vehicle RV" represented by the line 1200 in FIG. 12. The line 1200 indicates the boundary between a general braking operation (i.e., an operation for decelerating the vehicle in normal times) and an emergency braking operation (i.e., an operation for suddenly stopping the vehicle). For example, since the deceleration of a general braking operation is 0.4G or less, the line 1200 may have a slope corresponding to 0.4G. In the region 1201 above the line 1200, the arrival time is longer than the stop time, and if the driver of the surrounding vehicle RV performs a general braking operation, the surrounding vehicle RV can be stopped before reaching the predicted intersection 1102. Therefore, when the arrival time is greater than the threshold time (stop time), the driving support of the host vehicle SV may be suppressed. On the other hand, in the region 1202 below the line 1200, the arrival time is shorter than the stop time, and even if the driver of the surrounding vehicle RV performs a general braking operation (e.g., deceleration of 0.4G), the surrounding vehicle RV may reach the predicted intersection 1102 before stopping. Therefore, when the arrival time is equal to or less than the threshold time (stop time), the driving support of the host vehicle SV may be executed. Note that the processing unit 110 may continuously change the threshold time according to the speed of the surrounding vehicle RV, or may change it stepwise.

[0079] The possibility of collision may be determined based on the entry of the host vehicle 100 into the determination area 1103 instead of or in addition to the arrival time until the surrounding vehicle RV reaches the predicted intersection 1102. For example, when the host vehicle 100 enters the determination area 1103, the processing unit 110 may predict that there is a possibility of collision, and when the host vehicle 100 has not entered the determination area 1103, the processing unit 110 may determine that there is no possibility of collision.

[0080] Furthermore, the possibility of collision may be determined based on the difference (hereinafter referred to as "arrival time difference") between the predicted time until the surrounding vehicle RV reaches the predicted intersection 1102 and the predicted time until the host vehicle 100 reaches the predicted intersection 1102. When the arrival time difference is equal to or less than the threshold time, the processing unit 110 may predict that there is a possibility of collision, and when the arrival time difference is greater than the threshold time, the processing unit 110 may determine that there is no possibility of collision. The threshold time may be settable by the occupant of the host vehicle 100.

[0081] The possibility of collision may be determined by arbitrarily combining the above three conditions (i.e., the arrival time is equal to or less than the threshold time, the host vehicle 100 has entered the determination area 1103, and the arrival time difference is equal to or less than another threshold time). For example, when all of these four conditions are satisfied, the processing unit 110 may determine that there is a possibility of collision, and in other cases, the processing unit 110 may determine that there is no possibility of collision. Alternatively, when at least one of these four conditions is satisfied, the processing unit 110 may determine that there is a possibility of collision, and in other cases, the processing unit 110 may determine that there is no possibility of collision. Alternatively, when at least one of the two pre-set conditions among these four conditions is satisfied, the processing unit 110 may determine that there is a possibility of collision, and in other cases, the processing unit 110 may determine that there is no possibility of collision. Specifically, when the predicted time until the surrounding vehicle RV reaches the predicted intersection 1102 is less than the first threshold time, if the arrival time difference is less than the second threshold time, the processing unit 110 may predict that there is a possibility of collision, and if the arrival time difference is greater than the second threshold time, the processing unit 110 may predict that there is no possibility of collision.

[0082] In step S705, the processing unit 110 (for example, its support unit 110c) determines whether the support conditions are satisfied. When it is determined that the support conditions are satisfied, the processing unit 110 transitions the process to step S706, and in other cases, transitions the process to step S707. The support conditions may be conditions that should be satisfied in order to execute driving support. For example, the support conditions may be based on whether the speed of the surrounding vehicle RV is within a specified range. The specified range can be set in advance by a speed lower limit value and a speed upper limit value regarding the speed of the surrounding vehicle RV. When the speed of the surrounding vehicle RV is less than or equal to the speed lower limit value of the specified range, the driver of the surrounding vehicle RV is likely to notice the host vehicle 100 and decelerate the surrounding vehicle RV without colliding with the host vehicle 100. That is, the speed lower limit value of the specified range regarding the speed of the surrounding vehicle RV can be set to a value that can decelerate the surrounding vehicle RV without colliding with the host vehicle 100. Also, when the speed of the surrounding vehicle RV is greater than or equal to the upper limit value of the specified range, it is likely that the surrounding vehicle RV is not a vehicle traveling on the road where the host vehicle 100 enters, such as traveling on a highway near the road where the host vehicle 100 enters. That is, the upper limit value of the specified range regarding the speed of the surrounding vehicle RV can be set to a value that can determine whether the vehicle is traveling on the road where the host vehicle 100 enters or a vehicle traveling on a highway near the road. Thus, by executing / suppressing driving support according to whether the speed of the surrounding vehicle RV is within the specified range, it is possible to reduce the driver of the host vehicle 100 from feeling the annoyance of driving support.

[0083] In step S706, the processing unit 110 (for example, its support unit 110c) performs driving support for the host vehicle 100. As driving support for the host vehicle 100, the processing unit 110 may notify the passengers of the host vehicle 100 of the possibility of collision by the notification device 105, or perform a braking operation of the host vehicle 100 by the braking device 106.

[0084] In step S708, the processing unit 110 (for example, its prediction unit 110b) deletes from the storage unit 111 the determination area (the determination area stored in step S703) that has become unnecessary due to the execution of driving support. This suppresses the consumption of the capacity of the storage unit 111 by unnecessary information.

[0085] If it is determined in step S704 that there is no possibility of collision or if it is determined in step S705 that the support conditions are not satisfied, step S707 is executed. In step S707, the processing unit 110 (for example, its prediction unit 110b) determines whether the surrounding vehicle RV that is the processing target of the method in FIG. 7 has been unregistered in step S405 of FIG. 4. When the processing unit 110 determines that the registration of the surrounding vehicle RV has been canceled, the process transitions to step S708, and in other cases, the process transitions to step S702. When the registration of the surrounding vehicle RV has been canceled, it is considered that the surrounding vehicle RV no longer exists around the host vehicle 100. Therefore, the processing unit 110 ends the process without executing driving support regarding this surrounding vehicle RV. Also in this case, in step S708, the processing unit 110 (for example, its prediction unit 110b) deletes from the storage unit 111 the determination area that has become unnecessary.

[0086] When it is determined in step S707 that the registration of the surrounding vehicle RV has not been canceled, the process returns to step S702. In this case, when the predicted travel path of the host vehicle 100 and the predicted travel path of the surrounding vehicle RV still intersect, in step S703, a determination area is set with the predicted intersection 1102 as the reference position. When a vehicle (the host vehicle 100 or the surrounding vehicle RV) changes its position within the lane or changes lanes, the position of the predicted intersection 1102 may change. Since the surrounding vehicle information is repeatedly acquired, the processing unit 110 can detect such a change in the position of the predicted intersection 1102. Therefore, in step S703, the processing unit 110 (for example, its prediction unit 110b) re-sets the reference position based on the newly acquired surrounding vehicle information, and accordingly updates the determination area stored in the storage unit 111. As a result, the determination in step S704 is executed based on the updated determination area. If the predicted intersection 1102 cannot be determined in step S703, the most recently determined reference position and determination area may be maintained.

[0087] As described above, the processing unit 110 repeatedly determines the predicted intersection at predetermined time intervals. When the amount of change in the position of the predicted intersection is equal to or greater than a predetermined threshold amount of change, the processing unit 110 may increase the time threshold used for the comparison with the above-described arrival time. When the amount of change in the position of the predicted intersection is large, it is considered that the predicted trajectory of the host vehicle 100 or the surrounding vehicle RV has changed. Therefore, by increasing the time threshold, it becomes easier to predict that there is a possibility of collision, and thus safety is improved.

[0088] According to the method of FIG. 7, when a plurality of surrounding vehicles exist within the range 601 on the side of the host vehicle 100, individual reference positions are used for each of the plurality of surrounding vehicles. Specifically, the method of FIG. 7 is individually executed for each of the plurality of surrounding vehicles. As a result, the predicted intersections between the predicted travel path of the host vehicle 100 and the predicted travel paths of the surrounding vehicles are also determined for each of the plurality of surrounding vehicles. As a result, individual determination areas are set for each of the plurality of surrounding vehicles based on individual reference positions. Thereby, the possibility of collision with each of the plurality of surrounding vehicles can be appropriately predicted.

[0089] FIG. 13 illustrates an example of a process for executing driving assistance when a surrounding vehicle RV (FIG. 16) exists within a range 600 in front of the host vehicle 100 in step S503 (that is, the process when no risk position is included within a predetermined distance in the traveling direction of the host vehicle 100). The process shown in the flowchart of FIG. 13 is executed by the processing unit 110 according to a learning program read from the storage unit 111. The process of FIG. 13 may be started, for example, in response to the driving assistance setting being turned on. The process of FIG. 13 can be repeatedly executed until the driving assistance setting is turned off or the ignition of the vehicle 100 is turned off.

[0090] In step S1301, the processing unit 110 (for example, its prediction unit 110b) determines whether the vehicle speed of the host vehicle 100 is within a threshold range. If the processing unit 110 determines that the vehicle speed of the host vehicle 100 is within the threshold range, the process transitions to step S1302, and otherwise, the process transitions to step S1303. This determination may be made based on the vehicle speed and acceleration of the host vehicle 100 included in the latest host vehicle information. The upper end of the threshold value used in step S1301 is a value below which the vehicle speed after the vehicle 100 decelerates to turn (for example, make a left turn or a right turn) is, and may be, for example, 20 km / h. The lower end of the threshold value used in step S1301 is a value below which the vehicle speed of the vehicle 100 is in a stopped state or a substantially stopped state, and may be, for example, 2 km / h. The position where the host vehicle 100 is determined to be within the threshold range is represented as a turning preparation position 1601 (FIG. 16). Note that even if the host vehicle 100 does not turn, it can be within the threshold range. Even in this case, the processing unit 110 detects the turning preparation position 1601 and executes the processes after step S1302.

[0091] In step S1302, the processing unit 110 (for example, its prediction unit 110b) sets a determination area with the turning preparation position 1601 as the reference position, and stores the reference position and the determination area in the storage unit 111. The determination area may be an area where the possibility of a collision is predicted. Referring to FIG. 16, an example of the determination area 1602 set with the turning preparation position 1601 as the reference position will be described. The determination area 1602 may be a rectangle centered on the position in front of the left of the turning preparation position 1601 and including sides parallel to the vehicle length direction of the host vehicle 100. The length of the determination area 1602 in the vehicle width direction of the host vehicle 100 may be, for example, 3 m to 4 m, which is equivalent to the length of one lane. The length of the determination area 1602 in the vehicle length direction of the host vehicle 100 may be, for example, 9 m to 11 m, which is equivalent to the length of three lanes. The lower right corner of the determination area 1602 may overlap the turning preparation position 1601. Alternatively, the determination area 1602 may have other shapes. The position of the determination area 1602 with respect to the reference position may be set in advance (for example, at the time of manufacturing the vehicle 100 or at the time of software update) and stored in the storage unit 111. The processing unit 110 may expand the determination area 1602 to include the risk position when a risk position exists near the determination area 1602. The processing unit 110 sets the determination area 1602 so as to include the turning preparation position 1601 (i.e., the reference position) and offset it to the oncoming lane side (the left side in the example of FIG. 16) with respect to the host vehicle 100 in a direction orthogonal to the predicted travel path of the host vehicle 100. As a result, it becomes possible to appropriately predict the possibility of a collision that may occur when the host vehicle 100 turns left.

[0092] The processes after step S1303 are executed using the reference position and the determination area set in step S1302. As described above, since the method of FIG. 13 is repeatedly executed, steps S1301 and S1302 are also repeatedly executed. Therefore, while the vehicle speed of the host vehicle 100 is within the threshold range (for example, 2 km / h or more and less than 20 km / h), the reference position and the determination area are continuously updated, and the processes after step S1303 are executed using the latest reference position and determination area. In response to the vehicle speed of the host vehicle 100 being outside the threshold range (for example, less than 2 km / h or 20 km / h or more), the update of the reference position and the determination area is stopped, and the processes after step S1303 are executed using the reference position and the determination area at the time of the update stop. When the reference position and the determination area are not set at the time of execution of step S1303, the processing unit 110 may omit steps S1303 to S1310 and return the process to S1301.

[0093] In step S1303, the processing unit 110 (for example, its prediction unit 110b) determines the predicted turning trajectory 1604 of the host vehicle 100. The predicted turning trajectory 1604 may be the turning trajectory predicted when the host vehicle 100 turns toward the oncoming lane side (for example, makes a left turn). The predicted turning trajectory 1604 may be set in advance (for example, at the time of manufacturing the vehicle 100 or at the time of software update) and stored in the storage unit 111. The predicted turning trajectory 1604 set in advance in this way may be called the default predicted turning trajectory 1604.

[0094] A plurality of candidates for the predicted turning trajectory 1604 may be stored in the storage unit 111. The processing unit 110 (for example, its prediction unit 110b) may select one predicted turning trajectory 1604 from the plurality of candidates for the predicted turning trajectory 1604 based on the steering angle of the host vehicle 100 at the turning preparation position 1601 and use it for subsequent processing. For example, when the steering angle of the host vehicle 100 is small, the processing unit 110 may select a predicted turning trajectory 1604 with a small radius of curvature because it is considered that the host vehicle 100 is trying to make a left turn at a small intersection. On the other hand, when the steering angle of the host vehicle 100 is large, the processing unit 110 may select a predicted turning trajectory 1604 with a large radius of curvature because it is considered that the host vehicle 100 is trying to make a left turn at a large intersection.

[0095] In step S1304, the processing unit 110 (for example, its prediction unit 110b) specifies a surrounding vehicle RV existing within the range 600 in front of the host vehicle 100 as the vehicle to be processed in subsequent processing. If there is no surrounding vehicle RV within the range 600, the vehicle to be processed is not specified. If there are a plurality of surrounding vehicles RV within the range 600, any of these plurality of surrounding vehicles RV is specified as the vehicle to be processed. This specification may be performed based on the current position of the surrounding vehicle RV included in the latest surrounding vehicle information acquired from the surrounding vehicle RV. In the example shown in FIG. 16, one surrounding vehicle RV exists within the range 600.

[0096] In step S1305, the processing unit 110 (for example, its prediction unit 110b) predicts the possibility of collision between the host vehicle 100 and the surrounding vehicle RV in the determination area 1602. When it is determined that there is a possibility of collision between the host vehicle 100 and the surrounding vehicle RV, the processing unit 110 transitions the processing to step S1306, and in other cases, transitions the processing to step S1308.

[0097] The possibility of collision may be determined based on the intersection 1605 between the predicted turning trajectory 1604 determined in step S1303 and the predicted travel route 1603 of the surrounding vehicle RV being included in the determination region 1602. For example, when the intersection 1605 is included in the determination region 1602, the processing unit 110 may determine that there is a possibility of collision, and when the intersection 1605 is not included in the determination region 1602, the processing unit 110 may determine that there is no possibility of collision.

[0098] Furthermore, the possibility of collision may be determined based on an evaluation distance determined based on the predicted trajectory of the host vehicle 100 and the predicted trajectory of the surrounding vehicle RV. As described above, the evaluation distance is a distance for evaluating the approach situation between the host vehicle 100 and the surrounding vehicle RV.

[0099] With reference to FIG. 14, a specific example of a method for determining the possibility of collision based on the evaluation distance will be described. Steps S1401 and S1402 may be the same as steps S801 and S802 in FIG. 8, and thus duplicate descriptions will be omitted.

[0100] In step S1403, the processing unit 110 determines the distance between the straight-ahead trajectory of the host vehicle 100 and the surrounding vehicle RV as the evaluation distance. The straight-ahead trajectory is the trajectory when it is assumed that the host vehicle 100 travels straight. The process of step S1403 is executed when it is determined that the radius of curvature of the host vehicle 100 is equal to or greater than a threshold radius (for example, 3000 m). In this case, the occupants of the host vehicle 100 are considered to intend to travel straight with the host vehicle 100. Therefore, the processing unit 110 determines the evaluation distance using the straight-ahead trajectory of the host vehicle 100. With reference to FIG. 15(a), an example of the evaluation distance in step S1403 will be described. In this example, the distance 1501 between the straight-ahead trajectory 1000 of the host vehicle 100 and the surrounding vehicle RV is determined as the evaluation distance. In the description of FIG. 15, the distance between the trajectory and the vehicle may be the shortest distance between the trajectory and the center of the vehicle. Alternatively, other parts of the vehicle may be used for determining the distance.

[0101] In step S1404, the processing unit 110 determines the distance between the predicted trajectory of the host vehicle 100 and the surrounding vehicle RV as the evaluation distance. The processing unit 110 may use the predicted trajectory determined in step S1401. The process of step S1404 is executed when it is determined that the radius of curvature of the host vehicle 100 is less than the threshold radius (for example, 3000 m). In this case, it is considered that the occupant of the host vehicle 100 intends to turn the host vehicle 100. Therefore, the processing unit 110 determines the evaluation distance using the predicted trajectory of the host vehicle 100. Referring to FIG. 15(b), an example of the evaluation distance in step S1404 will be described. In this example, the distance 1511 between the predicted trajectory 1510 of the host vehicle 100 and the surrounding vehicle RV is determined as the evaluation distance. The predicted trajectory 1510 may be an arc having the determined radius of curvature.

[0102] Steps S1405 and S1406 may be the same as steps S805 and S806 in FIG. 8, so duplicate explanations are omitted. In step S1407, the processing unit 110 determines the distance between the straight - running trajectory of the host vehicle 100 and the surrounding vehicle RV as the evaluation distance. The method for determining the evaluation distance in step S1407 may be the same as the method for determining the evaluation distance in step S1403, so duplicate explanations are omitted.

[0103] In step S1408, the processing unit 110 determines the distance between the predicted trajectory of the surrounding vehicle RV and the host vehicle 100 as the evaluation distance. The processing unit 110 may use the predicted trajectory determined in step S1405. The process of step S1408 is executed when it is determined that the radius of curvature of the surrounding vehicle RV is less than the threshold radius (for example, 3000 m). In this case, it is considered that the occupant of the surrounding vehicle RV intends to turn the surrounding vehicle RV. Therefore, the processing unit 110 determines the evaluation distance using the predicted trajectory of the surrounding vehicle RV. Referring to FIG. 15(c), an example of the evaluation distance in step S1408 will be described. In this example, the distance 1521 between the predicted trajectory 1520 of the surrounding vehicle RV and the host vehicle 100 is determined as the evaluation distance. The predicted trajectory 1520 may be an arc having the determined radius of curvature.

[0104] In step S1409, the processing unit 110 determines whether the evaluation distance determined in step S1403, S1404, S1407, or S1408 is included in a predetermined range (for example, 3 m to 4 m, which is equivalent to the length of one lane). If the processing unit 110 determines that the evaluation distance is not included in the predetermined range, the process transitions to step S1410. If the processing unit 110 determines that the evaluation distance is included in the predetermined range, the process transitions to step S1411.

[0105] In step S1410, the processing unit 110 determines that there is no possibility of collision. In step S1411, the processing unit 110 determines that there is a possibility of collision. This determination result is used in step S1306.

[0106] When it is determined that the prediction accuracy of the predicted trajectory of the host vehicle 100 is less than the threshold accuracy and the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is less than the threshold accuracy, in step S1410, the processing unit 110 may predict that there is no possibility of collision between the host vehicle 100 and the surrounding vehicle RV. When the prediction accuracy of the predicted trajectory of each of the host vehicle 100 and the surrounding vehicle RV is low, there is a possibility that driving support (for example, notification to the occupant) is performed even though the two vehicles are not in a situation of approaching each other. Therefore, in such a case, by predicting that there is no possibility of collision and suppressing driving support (for example, notification to the occupant), it is possible to suppress the occupant from feeling annoyed.

[0107] As described above, according to the method of FIG. 14, the processing unit 110 determines an evaluation distance for evaluating the approaching situation between the host vehicle 100 and the surrounding vehicle RV based on the predicted trajectory of the host vehicle 100 and the predicted trajectory of the surrounding vehicle RV. In addition, the processing unit 110 selects a method for determining the evaluation distance from a plurality of candidate determination methods based on the prediction accuracy of the predicted trajectory of the host vehicle 100, the radius of curvature of the predicted trajectory of the host vehicle 100, the prediction accuracy of the predicted trajectory of the surrounding vehicle RV, and the radius of curvature of the predicted trajectory of the surrounding vehicle RV.

[0108] Returning to the description of FIG. 13, in step S1307, the processing unit 110 (for example, its support unit 110c) determines whether the support condition is satisfied. When it is determined that the support condition is satisfied, the processing unit 110 transfers the process to step S1308, and otherwise transfers the process to step S1309. Since step S1307 may be the same as step S705, duplicate descriptions are omitted.

[0109] In step S1308, the processing unit 110 (for example, its support unit 110c) performs driving support for the host vehicle 100. As driving support for the host vehicle 100, the processing unit 110 can notify the passengers of the host vehicle 100 of the possibility of collision by the notification device 105 or perform a braking operation of the host vehicle 100 by the braking device 150.

[0110] In step S1311, the processing unit 110 (for example, its prediction unit 110b) deletes from the storage unit 111 the reference position and the determination area (the reference position and the determination area stored in step S703) that have become unnecessary due to the execution of the driving support. This suppresses the consumption of the capacity of the storage unit 111 by unnecessary information.

[0111] If it is determined in step S1306 that there is no possibility of collision, or if it is determined in step S1307 that the assistance conditions are not satisfied, step S1309 is executed. In step S1309, the processing unit 110 (for example, its prediction unit 110b) determines whether the host vehicle 100 has moved away from the reference position stored in step S1302 by a predetermined distance (for example, 30 m) or more. If the processing unit 110 determines that the host vehicle 100 has moved away from the reference position by a predetermined distance or more, the process transitions to step S1311; otherwise, the process transitions to step S1310. When the host vehicle 100 has moved away from the reference position by a predetermined distance or more, it is considered that there is no possibility of the host vehicle 100 colliding with the surrounding vehicle RV at that point. Therefore, the processing unit 110 ends the process without performing driving assistance regarding this collision with the surrounding vehicle RV. Also in this case, in step S1311, the processing unit 110 (for example, its prediction unit 110b) deletes the unnecessary reference position and determination area from the storage unit 111.

[0112] If it is determined in step S1310 that the host vehicle 100 has not moved away from the reference position by a predetermined distance or more, step S1310 is executed. In step S1310, the processing unit 110 (for example, its prediction unit 110b) may update the predicted turning trajectory 1604 based on the change in the steering angle of the host vehicle 100. For example, when the host vehicle 100 is turning left at a steering angle larger than that assumed in the predicted turning trajectory 1604, the processing unit 110 may update the predicted turning trajectory 1604 so that the radius of curvature becomes smaller. On the other hand, when the host vehicle 100 is turning left at a steering angle smaller than that assumed in the predicted turning trajectory 1604, the processing unit 110 may update the predicted turning trajectory 1604 so that the radius of curvature becomes larger. The update of the predicted turning trajectory 1604 may be performed when the current steering angle of the host vehicle 100 becomes equal to or greater than the steering angle of the default predicted turning trajectory 1604. Thereafter, the processing unit 110 transitions the process to step S1305 and identifies the surrounding vehicle RV newly included within the range 600 as the target vehicle for subsequent processing. Also, the possibility of collision in step S1306 is determined based on the updated predicted turning trajectory 1604.

[0113] According to the method of FIG. 13, when there are a plurality of surrounding vehicles within the range 600 in front of the host vehicle 100, a common reference position (i.e., the steering preparation position 1601) is used for the plurality of surrounding vehicles. As a result, for each of the plurality of surrounding vehicles, a common determination area is set based on the common reference position. Thereby, it is possible to appropriately estimate the possibility of a collision when the host vehicle 100 turns toward the oncoming lane side (for example, when making a left turn).

[0114] According to the above-described embodiment, it is possible to appropriately predict the possibility of a collision according to the positions of the surrounding vehicles. As a result, it becomes possible to appropriately perform the driving support of the host vehicle 100. Note that even in a situation where the driving support based on the surrounding vehicle information acquired from the surrounding vehicle through vehicle-to-vehicle communication is not executed, the driving support based on other criteria (for example, based on the detection results of a camera or a radar) may be executed.

[0115] In the above-described driving support method, based on the fact that the surrounding vehicle RV is located within the range 600 or 601 of FIG. 6, this surrounding vehicle RV is targeted for prediction of the possibility of a collision. The processing unit 110 may determine whether or not to target the surrounding vehicle RV for prediction of the possibility of a collision based on other information. With reference to FIG. 17, an example of a method for determining the surrounding vehicle RV targeted for prediction of the possibility of a collision will be described.

[0116] The processing unit 110 may further determine whether or not to target the surrounding vehicle RV for prediction of the possibility of a collision based on the rotation angle 1703 of the travel vector 1702 of the surrounding vehicle RV with respect to the travel vector 1701 of the host vehicle 100. The travel vector 1701 may be a unit vector directed in the traveling direction of the vehicle. For the sake of explanation, the rotation angle 1703 is positive in the clockwise direction and negative in the counterclockwise direction. The processing unit 110 can determine the approaching direction of the surrounding vehicle RV based on the direction of the surrounding vehicle RV with respect to the host vehicle 100 and the rotation angle 1703 of the travel vector 1702 of the surrounding vehicle RV with respect to the travel vector 1701 of the host vehicle 100.

[0117] Even if the surrounding vehicle RV is included within the range 600 in front of the host vehicle 100, if the surrounding vehicle RV is traveling in the same direction as the host vehicle 100, or is traveling in the right or left direction relative to the host vehicle 100, it is considered that there is no possibility of collision between the host vehicle 100 and the surrounding vehicle RV. Therefore, when the surrounding vehicle RV is within the range 600 in front of the host vehicle 100 and the rotation angle 1703 is within a predetermined range (for example, 160° to 200°), the surrounding vehicle RV may be set as an object for determining the possibility of collision in the processes of FIGS. 7 and 13.

[0118] Even if the surrounding vehicle RV is included within the range 601 on the right side of the host vehicle 100, if the surrounding vehicle RV is traveling in the same direction as or in the opposite direction to the host vehicle 100, or is traveling in the right direction relative to the host vehicle 100, it is considered that there is no possibility of collision between the host vehicle 100 and the surrounding vehicle RV. Therefore, when the surrounding vehicle RV is within the range 601 on the right side of the host vehicle 100 and the rotation angle 1703 is within a predetermined range (for example, -110° to -70°), the surrounding vehicle RV may be set as an object for determining the possibility of collision in the processes of FIGS. 7 and 13.

[0119] Even if the surrounding vehicle RV is included within the range 601 on the left side of the host vehicle 100, if the surrounding vehicle RV is traveling in the same direction as or in the opposite direction to the host vehicle 100, or is traveling in the left direction relative to the host vehicle 100, it is considered that there is no possibility of collision between the host vehicle 100 and the surrounding vehicle RV. Therefore, when the surrounding vehicle RV is within the range 601 on the left side of the host vehicle 100 and the rotation angle 1703 is within a predetermined range (for example, 70° to 110°), the surrounding vehicle RV may be set as an object for determining the possibility of collision in the processes of FIGS. 7 and 13.

[0120] Next, in step S502 of FIG. 5, a process for determining whether to perform driving assistance using risk positions included within a predetermined distance will be described. The processing unit 110 may predict the possibility of a collision between the host vehicle 100 and surrounding vehicles RV based on the traveling trajectories of other vehicles associated with the risk positions in the risk position information 112 and the surrounding vehicle information. The traveling trajectories of other vehicles included in the risk position information 112 may be the traveling trajectories that the host vehicle 100 has crossed in the past. For example, in the process of FIG. 8, the processing unit 110 may use the traveling trajectories of other vehicles included in the risk position information 112 instead of the predicted trajectories of the surrounding vehicles RV.

[0121] Next, a specific example of the notification method by the processing unit 110 (for example, its support unit 110c) will be described. When the processing unit 110 predicts that there is a possibility of a collision between the host vehicle 100 and the surrounding vehicle RV and the host vehicle 100 performs a starting operation, the processing unit 110 may notify the occupant through the speaker 105c using a predetermined notification sound. The processing unit 110 may display approach information including a warning to the occupant on the MID 105a. When the processing unit 110 predicts that there is a possibility of a collision between the host vehicle 100 and the surrounding vehicle RV, the processing unit 110 may display the approaching direction of the surrounding vehicle RV on the HUD 105b.

[0122] Referring to FIG. 18, a specific example of the display by the MID 105a and the HUD 105b will be described. When the processing unit 110 predicts that there is a possibility of a collision between the host vehicle 100 and the surrounding vehicle RV, the processing unit 110 may display the icons shown in FIG. 18. Specifically, when the approaching direction of the surrounding vehicle RV with respect to the host vehicle 100 is within the range 600 in front of the host vehicle 100 and the host vehicle 100 turns to the left (for example, makes a left turn), the processing unit 110 may display on the MID 105a that another vehicle is approaching from in front of the host vehicle 100, and may display a warning to the front of the host vehicle 100 on the HUD 105b.

[0123] If the approaching direction of the surrounding vehicle RV with respect to the host vehicle 100 is within the range 601 on the right side of the host vehicle 100, the processing unit 110 may display on the MID105a that another vehicle is approaching from the right side of the host vehicle 100, and may display on the HUD105b a warning to the right side of the host vehicle 100. If the approaching direction of the surrounding vehicle RV with respect to the host vehicle 100 is within the range 601 on the left side of the host vehicle 100, the processing unit 110 may display on the MID105a that another vehicle is approaching from the left side of the host vehicle 100, and may display on the HUD105b a warning to the left side of the host vehicle 100.

[0124] <Summary of the Embodiment> [Item 1] A driving support device (108), a storage means (111) for storing risk position information (112) representing a risk position where the host vehicle (100) equipped with the driving support device may collide with another vehicle; an acquisition means (110a) for acquiring, by vehicle-to-vehicle communication from the surrounding vehicle (RV) existing around the host vehicle, surrounding vehicle information representing the vehicle speed, position, traveling locus, and yaw rate of the surrounding vehicle; a prediction means (110b) for predicting the possibility of collision between the host vehicle and the surrounding vehicle based on the host vehicle information representing the vehicle speed, position, traveling locus, and yaw rate of the host vehicle and the surrounding vehicle information; a notification means (110c) for notifying the occupant of the host vehicle based on the prediction result by the prediction means, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, the prediction means determines a predicted locus (1010, 1510) of the host vehicle based on the host vehicle information, determines a predicted locus (1021, 1520) of the surrounding vehicle based on the surrounding vehicle information, and determines an evaluation distance (1003, 1013, 1023, 1501, 1511, 1521) for evaluating the approaching situation between the host vehicle and the surrounding vehicle based on the predicted locus of the host vehicle and the predicted locus of the surrounding vehicle. A driving support device that predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle when the evaluation distance is not included in a predetermined range. According to this item, the driving support of the host vehicle can be appropriately performed. Specifically, excessive notification to the occupant can be suppressed. [Item 2] The prediction means Based on the vehicle speed of the host vehicle and the yaw rate of the host vehicle, determine the prediction accuracy of the predicted trajectory of the host vehicle, Based on the vehicle speed of the surrounding vehicle and the yaw rate of the surrounding vehicle, determine the prediction accuracy of the predicted trajectory of the surrounding vehicle, Based on the prediction accuracy of the predicted trajectory of the host vehicle, the radius of curvature of the predicted trajectory of the host vehicle, the prediction accuracy of the predicted trajectory of the surrounding vehicle, and the radius of curvature of the predicted trajectory of the surrounding vehicle, select a method for determining the evaluation distance from a plurality of candidate determination methods. The driving support device according to Item 1. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 3] When the surrounding vehicle exists within a first range (601) in front of the host vehicle and the prediction accuracy of the predicted trajectory of the host vehicle is equal to or higher than a threshold accuracy, the prediction means If the radius of curvature of the predicted trajectory of the host vehicle is equal to or greater than a threshold radius, determine the distance (1501) between the straight-ahead trajectory (1500) of the host vehicle and the surrounding vehicle as the evaluation distance, If the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, determine the distance (1511) between the predicted trajectory (1510) of the host vehicle and the surrounding vehicle as the evaluation distance. The driving support device according to Item 2. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 4] When the surrounding vehicle exists within the first range in front of the host vehicle, the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, and the prediction accuracy of the predicted trajectory of the surrounding vehicle is equal to or higher than the threshold accuracy, the prediction means If the radius of curvature of the predicted trajectory of the surrounding vehicle is greater than or equal to the threshold radius, the distance (1501) between the straight - ahead trajectory (1500) of the host vehicle and the surrounding vehicle is determined as the evaluation distance. The driving support device according to item 3, wherein if the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, the distance (1521) between the predicted trajectory (1520) of the surrounding vehicle and the host vehicle is determined as the evaluation distance. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 5] The prediction means predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle when the surrounding vehicle exists within a first range in front of the host vehicle, the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, and the prediction accuracy of the predicted trajectory of the surrounding vehicle is less than the threshold accuracy. The driving support device according to item 4. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 6] When the surrounding vehicle exists within a second range (600) on the side of the host vehicle, the prediction means If the prediction accuracy of the predicted trajectory of the host vehicle is greater than or equal to the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is greater than or equal to the threshold radius, the intersection point (1002) between the straight - ahead trajectory (1000) of the host vehicle and the straight - ahead trajectory (1001) of the surrounding vehicle is determined as the predicted intersection point. If the prediction accuracy of the predicted trajectory of the host vehicle is greater than or equal to the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, the intersection point (1012) between the predicted trajectory (1010) of the host vehicle and the straight - ahead trajectory (1011) of the surrounding vehicle is determined as the predicted intersection point. If the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, the prediction accuracy of the predicted trajectory of the surrounding vehicle is greater than or equal to the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is greater than or equal to the threshold radius, the intersection point (1002) between the straight - ahead trajectory (1000) of the host vehicle and the straight - ahead trajectory (1001) of the surrounding vehicle is determined as the predicted intersection point. If the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, the prediction accuracy of the predicted trajectory of the surrounding vehicle is equal to or higher than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, an intersection point (1022) between the straight - line trajectory (1020) of the host vehicle and the predicted trajectory (1021) of the surrounding vehicle is determined as a predicted intersection point. The driving support device according to any one of Items 1 to 5, which determines the evaluation distance based on the predicted intersection point and the current position of the host vehicle. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 7] When the surrounding vehicle exists within the second range on the side of the host vehicle, the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, and the prediction accuracy of the predicted trajectory of the surrounding vehicle is less than the threshold accuracy, the prediction means predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle. The driving support device according to Item 6. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 8] When the surrounding vehicle exists within the second range on the side of the host vehicle, Based on the surrounding vehicle information, a time - to - arrival until the surrounding vehicle reaches the predicted intersection point is determined. When the time - to - arrival is equal to or less than a first threshold time, the prediction means predicts that there is a possibility of collision between the host vehicle and the surrounding vehicle. The driving support device according to Item 7, wherein the first threshold time is determined based on the vehicle speed of the surrounding vehicle. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 9] The prediction means Repeatedly determines the predicted intersection point at a predetermined time interval. The driving support device according to Item 8, which increases the first threshold time when a change amount of the position of the predicted intersection point is equal to or greater than a predetermined threshold change amount. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 10] The prediction means repeatedly determines at a predetermined time interval whether the surrounding vehicle exists within a first range in front of the host vehicle, and repeatedly determines at a predetermined time interval whether the surrounding vehicle exists within a second range on the side of the host vehicle. The driving support device according to any one of Items 1 to 9. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 11] The risk position information further includes a travel locus of another vehicle associated with the risk position, and when the risk position is included within the predetermined distance in the traveling direction of the host vehicle, the prediction means is based on the travel locus of the other vehicle associated with the risk position and the surrounding vehicle information. The driving support device according to any one of Items 1 to 10, which predicts the possibility of collision between the host vehicle and the surrounding vehicle. According to this item, the driving support of the host vehicle can be performed more appropriately. [Item 12] The notification means when it is predicted that there is a possibility of collision between the host vehicle and the surrounding vehicle and the host vehicle performs a starting operation, notifies the occupant using a predetermined notification sound, the host vehicle includes a first display means (105a) and a second display means (105b) provided at a position different from the first display means, the notification means displays approach information including alerting the occupant on the first display means, and when it is predicted that there is a possibility of collision between the host vehicle and the surrounding vehicle, displays the approaching direction of the surrounding vehicle on the second display means. The driving support device according to any one of Items 1 to 11. According to this item, notification can be performed so that the occupant can easily recognize it. [Item 13] The driving support device according to item 12, wherein the prediction means determines the approaching direction of the surrounding vehicle based on the direction of the surrounding vehicle with respect to the host vehicle and the rotation angle of the traveling route of the surrounding vehicle with respect to the traveling route of the host vehicle. According to this item, notification can be made so that it is easy for the occupant to recognize. [Item 14] Of the right side and the left side, the side of the road where passage is obligatory in the area where the host vehicle is located is defined as the first side, and the side opposite to the first side is defined as the second side. When it is predicted that there is a possibility of collision between the host vehicle and the surrounding vehicle, if the approaching direction is within a first range in front of the host vehicle and the host vehicle turns to the second side, the first display means displays that another vehicle is approaching from in front of the host vehicle, and the second display means displays a warning to pay attention to the front of the host vehicle, if the approaching direction is within a second range on the first side of the host vehicle, the first display means displays that another vehicle is approaching from the first side of the host vehicle, and the second display means displays a warning to pay attention to the first side of the host vehicle, if the approaching direction is within a second range on the second side of the host vehicle, the first display means displays that another vehicle is approaching from the second side of the host vehicle, and the second display means displays a warning to pay attention to the second side of the host vehicle, the driving support device according to item 13. According to this item, notification can be made so that it is easy for the occupant to recognize. [Item 15] A driving support method, a storage step in which a storage means (111) stores risk position information (112) representing a risk position where the host vehicle (100) may collide with another vehicle; an acquisition step in which an acquisition means acquires surrounding vehicle information representing the vehicle speed, position, traveling locus, and yaw rate of a surrounding vehicle (RV) from the surrounding vehicles existing around the host vehicle by vehicle-to-vehicle communication; A prediction step in which a prediction means predicts a possibility of collision between the host vehicle and the surrounding vehicles based on host vehicle information representing the vehicle speed, position, travel locus, and yaw rate of the host vehicle and the surrounding vehicle information; An informing step in which an informing means informs the occupant of the host vehicle based on the prediction result by the prediction means, and having: In the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, Determine a predicted locus (1010, 1510) of the host vehicle based on the host vehicle information, and determine a predicted locus (1021, 1520) of the surrounding vehicle based on the surrounding vehicle information, Based on the predicted locus of the host vehicle and the predicted locus of the surrounding vehicle, determine an evaluation distance (1003, 1013, 1023, 1501, 1511, 1521) for evaluating the approach situation between the host vehicle and the surrounding vehicle, A driving support method for predicting that there is no possibility of collision between the host vehicle and the surrounding vehicle when the evaluation distance is not included in a predetermined range. According to this item, driving support of the host vehicle can be appropriately performed. Specifically, excessive notification to the occupant can be suppressed. [Item 16] In a computer, A storage step of storing risk position information (112) representing a risk position where the host vehicle (100) may collide with other vehicles; An acquisition step of acquiring, by vehicle-to-vehicle communication from surrounding vehicles (RV) existing around the host vehicle, surrounding vehicle information representing the vehicle speed, position, travel locus, and yaw rate of the surrounding vehicles; A prediction step of predicting a possibility of collision between the host vehicle and the surrounding vehicles based on host vehicle information representing the vehicle speed, position, travel locus, and yaw rate of the host vehicle and the surrounding vehicle information; A program for causing the computer to execute an informing step of informing the occupant of the host vehicle based on the prediction result in the prediction step, In the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, Determine a predicted trajectory (1010, 1510) of the host vehicle based on the host vehicle information, and determine a predicted trajectory (1021, 1520) of the surrounding vehicle based on the surrounding vehicle information. Based on the predicted trajectory of the host vehicle and the predicted trajectory of the surrounding vehicle, determine an evaluation distance (1003, 1013, 1023, 1501, 1511, 1521) for evaluating the approaching situation between the host vehicle and the surrounding vehicle. A program that predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle when the evaluation distance is not included in a predetermined range. According to this item, the driving support of the host vehicle can be appropriately performed. Specifically, excessive notification to the occupant can be suppressed.

[0125] The invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the gist of the invention.

Explanation of Signs

[0126] 100: Vehicle, 101: Sensor group, 102: Turn signal lever, 103: GNSS antenna, 104: Inter-vehicle communication antenna, 105: Notification device, 106: Braking device, 107: Turn signal, 108: Control device

Claims

1. A driving support device, a storage means for storing risk position information representing a risk position where there is a possibility that the host vehicle equipped with the driving support device may collide with another vehicle; an acquisition means for acquiring, by vehicle-to-vehicle communication, from surrounding vehicles existing around the host vehicle, surrounding vehicle information representing the vehicle speed, position, travel locus, and yaw rate of the surrounding vehicles; a prediction means for predicting the possibility of collision between the host vehicle and the surrounding vehicles based on the host vehicle information representing the vehicle speed, position, travel locus, and yaw rate of the host vehicle and the surrounding vehicle information; a notification means for notifying the occupants of the host vehicle based on the prediction result by the prediction means, wherein when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, the prediction means determines a predicted locus of the host vehicle based on the host vehicle information, determines a predicted locus of the surrounding vehicle based on the surrounding vehicle information, determines an evaluation distance for evaluating the approach situation between the host vehicle and the surrounding vehicle based on the predicted locus of the host vehicle and the predicted locus of the surrounding vehicle, and predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle when the evaluation distance is not included in a predetermined range. A driving support device.

2. The prediction means determines the prediction accuracy of the predicted locus of the host vehicle based on the vehicle speed of the host vehicle and the yaw rate of the host vehicle, determines the prediction accuracy of the predicted locus of the surrounding vehicle based on the vehicle speed of the surrounding vehicle and the yaw rate of the surrounding vehicle, and selects a determination method for the evaluation distance from a plurality of candidate determination methods based on the prediction accuracy of the predicted locus of the host vehicle, the radius of curvature of the predicted locus of the host vehicle, the prediction accuracy of the predicted locus of the surrounding vehicle, and the radius of curvature of the predicted locus of the surrounding vehicle. The driving support device according to Claim 1.

3. When there is a surrounding vehicle within a first range in front of the host vehicle and the prediction accuracy of the predicted locus of the host vehicle is equal to or higher than a threshold accuracy, if the radius of curvature of the predicted locus of the host vehicle is equal to or greater than a threshold radius, the driving support device according to Claim 2, wherein the distance between the straight-ahead locus of the host vehicle and the surrounding vehicle is determined as the evaluation distance. if the radius of curvature of the predicted locus of the host vehicle is less than the threshold radius, the distance between the predicted locus of the host vehicle and the surrounding vehicle is determined as the evaluation distance.

4. When the prediction means determines that there is a surrounding vehicle within the first range in front of the host vehicle, the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, and the prediction accuracy of the predicted trajectory of the surrounding vehicle is equal to or higher than the threshold accuracy, if the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or larger than the threshold radius, the distance between the straight-ahead trajectory of the host vehicle and the surrounding vehicle is determined as the evaluation distance, if the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, the distance between the predicted trajectory of the surrounding vehicle and the host vehicle is determined as the evaluation distance. The driving support device according to claim 3. **Claim 5** When the prediction means determines that there is a surrounding vehicle within the first range in front of the host vehicle, the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, and the prediction accuracy of the predicted trajectory of the surrounding vehicle is less than the threshold accuracy, the prediction means predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle. The driving support device according to claim 4. **Claim 6** When the prediction means determines that there is a surrounding vehicle within the second range beside the host vehicle, if the prediction accuracy of the predicted trajectory of the host vehicle is equal to or higher than the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is equal to or larger than the threshold radius, the intersection point between the straight-ahead trajectory of the host vehicle and the straight-ahead trajectory of the surrounding vehicle is determined as the predicted intersection point, if the prediction accuracy of the predicted trajectory of the host vehicle is equal to or higher than the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, the intersection point between the predicted trajectory of the host vehicle and the straight-ahead trajectory of the surrounding vehicle is determined as the predicted intersection point, if the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, the prediction accuracy of the predicted trajectory of the surrounding vehicle is equal to or higher than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or larger than the threshold radius, the intersection point between the straight-ahead trajectory of the host vehicle and the straight-ahead trajectory of the surrounding vehicle is determined as the predicted intersection point, if the prediction accuracy of the predicted trajectory of the host vehicle is less than the threshold accuracy, the prediction accuracy of the predicted trajectory of the surrounding vehicle is equal to or higher than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, the intersection point between the straight-ahead trajectory of the host vehicle and the predicted trajectory of the surrounding vehicle is determined as the predicted intersection point, The evaluation distance is determined based on the predicted intersection point and the current position of the host vehicle. The driving support device according to claim 1. **Claim 7** The prediction means predicts that there is no possibility of collision between the host vehicle and the surrounding vehicle when the surrounding vehicle exists within the second range on the side of the host vehicle, the prediction accuracy of the prediction trajectory of the host vehicle is less than the threshold accuracy, and the prediction accuracy of the prediction trajectory of the surrounding vehicle is less than the threshold accuracy. The driving support device according to claim 6.

8. When the surrounding vehicle exists within the second range on the side of the host vehicle, the prediction means determines the arrival time until the surrounding vehicle arrives at the predicted intersection based on the surrounding vehicle information, predicts that there is a possibility of collision between the host vehicle and the surrounding vehicle when the arrival time is less than or equal to a first threshold time, The driving support device according to claim 7, wherein the first threshold time is determined based on the vehicle speed of the surrounding vehicle.

9. The prediction means repeatedly determines the predicted intersection at predetermined time intervals, The driving support device according to claim 8, wherein when the amount of change in the position of the predicted intersection is greater than or equal to a predetermined threshold amount of change, the first threshold time is increased.

10. The prediction means repeatedly determines at predetermined time intervals whether the surrounding vehicle exists within a first range in front of the host vehicle, The driving support device according to claim 1, wherein it repeatedly determines at predetermined time intervals whether the surrounding vehicle exists within a second range on the side of the host vehicle.

11. The risk position information further includes the driving trajectory of another vehicle associated with the risk position, When the risk position is included within the predetermined distance in the traveling direction of the host vehicle, the prediction means predicts the possibility of collision between the host vehicle and the surrounding vehicle based on the driving trajectory of the other vehicle associated with the risk position and the surrounding vehicle information. The driving support device according to claim 1.

12. The notification means notifies the occupant using a predetermined notification sound when it is predicted that there is a possibility of collision between the host vehicle and the surrounding vehicle and the host vehicle performs a starting operation, The host vehicle includes a first display means and a second display means provided at a position different from the first display means, The notification means displays approach information including alerting the occupant on the first display means, The driving support device according to claim 1, wherein when it is predicted that there is a possibility of collision between the host vehicle and the surrounding vehicle, the approaching direction of the surrounding vehicle is displayed on the second display means.

13. The driving support device according to claim 12, wherein the prediction means determines the approaching direction of the surrounding vehicle based on the direction of the surrounding vehicle with respect to the host vehicle and the rotation angle of the traveling route of the surrounding vehicle with respect to the traveling route of the host vehicle.

14. Of the right side and the left side, the side of the road where passage is obligatory in the area where the host vehicle is located is defined as the first side, and the side opposite to the first side is defined as the second side. When it is predicted that there is a possibility of collision between the host vehicle and the surrounding vehicle, if the approaching direction is within a first range in front of the host vehicle and the host vehicle turns to the second side, the first display means displays that another vehicle is approaching from in front of the host vehicle, and the second display means displays a warning to pay attention to the front of the host vehicle. if the approaching direction is within a second range on the first side of the host vehicle, the first display means displays that another vehicle is approaching from the first side of the host vehicle, and the second display means displays a warning to pay attention to the first side of the host vehicle. if the approaching direction is within a second range on the second side of the host vehicle, the first display means displays that another vehicle is approaching from the second side of the host vehicle, and the second display means displays a warning to pay attention to the second side of the host vehicle. The driving support device according to claim 13.

15. A driving support method, comprising: a storage step in which a storage means stores risk position information representing a risk position where the host vehicle may collide with another vehicle; an acquisition step in which an acquisition means acquires surrounding vehicle information representing the vehicle speed, position, traveling locus, and yaw rate of the surrounding vehicle from the surrounding vehicles existing around the host vehicle by vehicle-to-vehicle communication; a prediction step in which a prediction means predicts the possibility of collision between the host vehicle and the surrounding vehicle based on host vehicle information representing the vehicle speed, position, traveling locus, and yaw rate of the host vehicle and the surrounding vehicle information; an informing step in which an informing means informs the occupant of the host vehicle based on the prediction result by the prediction means, and in the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, a predicted locus of the host vehicle is determined based on the host vehicle information, and a predicted locus of the surrounding vehicle is determined based on the surrounding vehicle information. Based on the predicted trajectory of the host vehicle and the predicted trajectory of the surrounding vehicles, determine an evaluation distance for evaluating the approaching situation between the host vehicle and the surrounding vehicles. A driving assistance method for predicting that there is no possibility of collision between the host vehicle and the surrounding vehicles when the evaluation distance is not included in a predetermined range.

16. On a computer, A storage step of storing risk position information representing a risk position where the host vehicle may collide with other vehicles; An acquisition step of acquiring, from surrounding vehicles existing around the host vehicle, by vehicle-to-vehicle communication, surrounding vehicle information representing the vehicle speed, position, traveling trajectory, and yaw rate of the surrounding vehicles; A prediction step of predicting the possibility of collision between the host vehicle and the surrounding vehicles based on the host vehicle information representing the vehicle speed, position, traveling trajectory, and yaw rate of the host vehicle and the surrounding vehicle information; A program for causing the computer to execute a notification step of notifying the occupant of the host vehicle based on the prediction result in the prediction step, In the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, Determine the predicted trajectory of the host vehicle based on the host vehicle information, and determine the predicted trajectory of the surrounding vehicle based on the surrounding vehicle information. Based on the predicted trajectory of the host vehicle and the predicted trajectory of the surrounding vehicles, determine an evaluation distance for evaluating the approaching situation between the host vehicle and the surrounding vehicles. A program for predicting that there is no possibility of collision between the host vehicle and the surrounding vehicles when the evaluation distance is not included in a predetermined range.

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