Driving assistance device and driving assistance method

Abstract

To provide an advantageous technique for appropriately performing driving assistance for a self-vehicle.SOLUTION: A driving assistance device includes: a storage section that stores risk location information indicating a location where a self-vehicle on which the driving assistance device is mounted may collide with another vehicle; an assistance section that performs driving assistance for the self-vehicle on the basis of the risk location information; an acquisition section that acquires surrounding vehicle information through vehicle-to-vehicle communication from a surrounding vehicle present around the self-vehicle; an identification section that identifies an intersection point between a traveling trajectory of the self-vehicle and a traveling trajectory of the surrounding vehicle; and an update section that updates the risk location information on the basis of the intersection point identified by intersection point identification operation. The identification section executes, in a case where the surrounding vehicle is present within a first range in front of the self-vehicle, the intersection point identification operation using a location at which the self-vehicle accelerates after decelerating to a threshold value or less or a location at which the self-vehicle temporarily stops as a first reference location, and executes, in a case where the surrounding vehicle is present within a second range on a side of the self-vehicle, the intersection point identification operation using an intersection point between a predicted course of the self-vehicle and a predicted course of the surrounding vehicle as a second reference location.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a driving assistance device and a driving assistance method. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transportation systems that take into consideration vulnerable traffic participants have been gaining momentum. To achieve this, research and development is being focused on research and development of preventive safety technology to further improve traffic safety and convenience. A device that performs driving assistance to prevent collisions with other vehicles (surrounding vehicles) without using map information is known. Patent Document 1 discloses a driving assistance device that registers in a storage unit position information of an intersection where the driving trajectory of the vehicle and the driving trajectory of the other vehicle intersect, and provides driving assistance to the vehicle when passing through the intersection again. Patent Document 2 discloses a technology that generates intersection characteristic data that indicates the characteristics of an intersection using driving trajectory data outside the intersection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7054636 [Patent Document 2] JP 2019-105684 A Summary of the Invention [Problem to be solved by the invention]

[0004] The driving assistance device may identify a risk position where the vehicle may collide with another vehicle based on the travel trajectory of the vehicle and the travel trajectory of the other vehicle, and may use the risk position for driving assistance. However, in a preventive safety technology, if the intersection position is not appropriately identified, for example, if the risk position is excessively identified for a point where the need for driving assistance is relatively low, or if the risk position is not identified for a point where the need for driving assistance is relatively high, it may be difficult to appropriately perform driving assistance. Some aspects of the present disclosure aim to provide a technology that is advantageous for appropriately performing driving assistance for the vehicle. This, in turn, contributes to the development of a sustainable transportation system. [Means for solving the problem]

[0005] According to some embodiments, a driving assistance device is provided, the driving assistance device comprising: a storage means for storing risk position information indicating a position where a vehicle equipped with the driving assistance device may collide with another vehicle; an assistance means for providing driving assistance for the vehicle based on the risk position information; an acquisition means for acquiring surrounding vehicle information indicating the vehicle speed, position, and driving trajectory of the surrounding vehicles from surrounding vehicles present around the vehicle via vehicle-to-vehicle communication; an identification means for performing an intersection identification operation for identifying an intersection between the driving trajectory of the vehicle and the driving trajectory of the surrounding vehicles; and an update means for updating the risk position information based on the intersection identified by the intersection identification operation, wherein when the surrounding vehicle is present within a first range in front of the vehicle, the identification means performs the intersection identification operation using a position where the vehicle accelerates after decelerating to a threshold value or below or a position where the vehicle is temporarily stopped as a first reference position, and when the surrounding vehicle is present within a second range to the side of the vehicle, the identification means performs the intersection identification operation using an intersection between a predicted path of the vehicle and a predicted path of the surrounding vehicle as a second reference position. Effect of the Invention

[0006] According to some embodiments, an advantageous technique is provided for appropriately providing driving assistance for a vehicle. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram illustrating an example configuration of a vehicle according to some embodiments. [Diagram 2] FIG. 13 illustrates an example of risk location information according to some embodiments. [Diagram 3] 11A and 11B are schematic diagrams illustrating examples of trajectory intersections according to some embodiments. [Figure 4] 1 is a schematic diagram illustrating an example of a driving assistance method according to some embodiments. [Diagram 5] 1 is a schematic diagram illustrating the presence or absence of risk locations within a region of interest according to some embodiments. [Figure 6] FIG. 1 is a flow diagram illustrating an example of a method for registering nearby vehicles according to some embodiments. [Figure 7] 5 is a schematic diagram illustrating an example of a range in which a surrounding vehicle is detected according to some embodiments. FIG. [Figure 8] FIG. 11 is a flow diagram illustrating an example of an intersection identifying operation for a nearby vehicle ahead according to some embodiments. [Figure 9] 5A and 5B are schematic diagrams illustrating an example of an intersection identifying operation for a nearby vehicle ahead according to some embodiments. [Figure 10] 11 is a flow diagram illustrating an example of an intersection identification operation for a nearby vehicle to the side according to some embodiments. [Figure 11] 11 is a schematic diagram illustrating an example of an intersection identifying operation regarding a nearby vehicle to the side according to some embodiments; [Figure 12] 10A and 10B are schematic diagrams illustrating an example of a method for determining a nearby vehicle to be determined according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the 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 features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. In addition, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0009] <Vehicle configuration example> With reference to FIG. 1, a configuration example 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 Global Navigation Satellite System (GNSS) antenna 102, a vehicle-to-vehicle communication antenna 103, a notification device 104, a braking device 105, and a control device 106. 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 drive device, a transmission, and lighting devices. 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.

[0010] The control device 106 controls the overall operation of the vehicle 100. As described later, the control device 106 executes driving assistance for the vehicle 100 in which the control device 106 is mounted. Therefore, the control device 106 may be called a driving assistance device. The driving assistance provided by the control device 106 may be collision prevention assistance for preventing (reducing) collisions with other vehicles. In some embodiments, the control device 106 can execute collision prevention assistance without using map information. In the following description, the vehicle 100 may be referred to as the host vehicle 100 in order to easily distinguish it from other vehicles. Also, a vehicle different from the vehicle 100 may be referred to as another vehicle. Among the other vehicles, a vehicle currently present around the host vehicle 100 may be referred to as a surrounding vehicle. The surrounding vehicle may be a vehicle currently capable of vehicle-to-vehicle communication with the host vehicle 100.

[0011] The sensor group 101 includes various sensors for performing driving assistance for 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. The sensor group 101 may also include external detection sensors such as a camera, a millimeter wave radar, and a lidar (Light Detection and Ranging: LIDAR) that can detect objects around the vehicle 100. The sensor group 101 outputs the detection results to the control device 106.

[0012] The GNSS antenna 102 receives radio waves for position measurement transmitted from GNSS satellites. For example, the GNSS antenna 102 can be used to obtain information on the current position and / or travel path (travel history) of the vehicle 100. The vehicle-to-vehicle communication antenna 103 is an antenna for transmitting and receiving various data to and from surrounding vehicles. For example, the vehicle-to-vehicle communication antenna 103 can be used to obtain information on the current position, speed, and travel path of the surrounding vehicles.

[0013] The notification device 104 is a device that notifies the occupants (e.g., the driver) of the vehicle 100. When there is a possibility that the vehicle 100 will collide with a surrounding vehicle, the control device 106 can notify the occupants of the vehicle 100 of the possibility of a collision with the surrounding vehicle by the notification device 104 as driving assistance. For example, the notification device 104 may include a display unit such as a display and display information indicating the possibility of a collision with the surrounding vehicle on the display unit, or may include an audio output unit such as a speaker and output information indicating the possibility of a collision with the surrounding vehicle from the audio output unit by voice or the like.

[0014] The braking device 105 is a device, such as a brake, for performing a braking operation of the vehicle 100. When there is a possibility that the vehicle 100 will collide with a surrounding vehicle, the control device 106 operates the braking device 105 as a driving assistance to assist in decelerating the vehicle 100, thereby making it possible to avoid a collision with the surrounding vehicle.

[0015] The control device 106 is a device (computer) that controls the vehicle 100, and can be configured, for example, by an ECU (Electric Control Unit). The control device 106 can perform driving assistance by vehicle-to-vehicle communication with other vehicles and processing within the vehicle 100. For example, the control device 106 can perform driving assistance without using map information. The control device 106 includes a processing unit 110, a storage unit 111, a GNSS module 113, and a vehicle-to-vehicle communication module 114, which are connected by a bus (not shown).

[0016] The processing unit 110 is a processor represented by a CPU (Central Processing Unit), and executes a program 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, and the like, and stores a program (driving assistance program) for the processing unit 110 to execute driving assistance processing of the vehicle 100, a program (learning program) for the processing unit 110 to learn risk positions, various data, and the like. The storage unit 111 may store risk position information 112 created based on an intersection between the travel trajectory of the vehicle 100 and the travel trajectory of another vehicle. 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 another vehicle, or a position where there is a high possibility of such a collision. The risk position information 112 may be managed as a database.

[0017] The GNSS module 113 receives position information of the vehicle 100 and the like from GNSS satellites via the GNSS antenna 102. In addition, the vehicle-to-vehicle communication module 114 receives various types of information from other vehicles via the vehicle-to-vehicle communication antenna 103.

[0018] The processing unit 110 may include an acquisition unit 110a, a support unit 110b, a specification unit 110c, and an update unit 110d in order to execute driving support (collision prevention support in some embodiments) for the vehicle 100. Note that the processing unit 110 is not limited to a configuration including each of the units 110a to 110d. Other units may be added or some units may be omitted depending on the type of driving support executed by the vehicle 100.

[0019] The acquisition unit 110a acquires surrounding vehicle information indicating the current position, vehicle speed, and traveling trajectory of the surrounding vehicle from the surrounding vehicles existing around the vehicle 100 via the vehicle-to-vehicle communication antenna 103 (vehicle-to-vehicle communication module 114). The surrounding vehicle information may explicitly or implicitly indicate the current position, vehicle speed, and traveling trajectory of the surrounding vehicle. For example, the surrounding vehicle information may include the vehicle speed as it is, or may include information for calculating the vehicle speed (current and immediately preceding two geographical positions and their positioning times). The acquisition unit 110a may acquire host vehicle information indicating the current position, speed, and traveling trajectory of the vehicle 100 via the sensor group 101 and the GNSS antenna 102 (GNSS module 113).

[0020] The support unit 110b predicts the possibility of the vehicle 100 colliding with another vehicle in a target area in front of the vehicle 100 based on the subject vehicle information and the surrounding vehicle information acquired by the acquisition unit 110a, and controls driving support (collision prevention support) of the vehicle 100 based on the prediction result. The target area may be understood as a target area (driving support area) for performing driving support to prevent a collision between the vehicle 100 and another vehicle, and may be simply referred to as a "target area" below. In some embodiments, the support unit 110b may execute at least one of a notification to the occupants of the vehicle 100 by the notification device 104 and a deceleration support of the vehicle 100 by the braking device 105 as driving support for the vehicle 100.

[0021] Furthermore, the support unit 110b may provide driving support for the vehicle 100 based on the risk location information 112. For example, the support unit 110b may change the degree of driving support (collision prevention support) for the vehicle 100 depending on whether or not at least one risk location among the multiple risk locations included in the risk location information 112 exists within the target area.

[0022] For example, when at least one risk position exists within the target area, the support unit 110b increases the degree of driving support of the vehicle 100 compared to when no risk position exists within the target area. Examples of increasing the degree of driving support of the vehicle 100 include relaxing the operating conditions of the driving support so that the driving support is more likely to be activated, increasing the notification level of the notification device 104, and increasing the deceleration of the vehicle 100 by the braking device 105. Examples of relaxing the operating conditions of the driving support include increasing the time threshold for activating the driving support with respect to the time to collision (TTC: Time To Collision) calculated as the collision possibility of the vehicle 100.

[0023] The identification unit 110c identifies an intersection between the travel trajectory of the vehicle 100 and the travel trajectory of the surrounding vehicle. The operation of identifying an intersection between the travel trajectory of the vehicle 100 and the travel trajectory of the surrounding vehicle is hereinafter referred to as an intersection identification operation. The intersection between the travel trajectory of the vehicle 100 and the travel trajectory of the surrounding vehicle is hereinafter referred to as a trajectory intersection. There is a possibility that a road intersection exists near the trajectory intersection. The conditions for starting the intersection identification operation and the details of the intersection identification operation will be described later.

[0024] The update unit 110d updates the risk location information 112 stored in the storage unit 111 based on the trajectory intersection identified by the intersection identifying operation. For example, the update unit 110d may update the risk location information 112 by adding the trajectory intersection to the risk location information 112. Alternatively or in addition to this, the update unit 110d may update the risk location information 112 by correcting any of the risk locations included in the risk location information 112 based on the trajectory intersection.

[0025] Next, an example of the risk location information 112 will be described with reference to FIG. 2. In the example of FIG. 2, the risk location information 112 is described in a table format, but the risk location information 112 may be in another format. The risk location information 112 has a record for each risk location. The columns of the risk location information 112 shown in FIG. 2 are an example. The risk location information 112 may include other columns, or may not include some of the columns shown in FIG. 2.

[0026] The risk location information 112 may include information on a risk location ID, a registration date and time, coordinates, and a passing direction for each risk location. The risk location ID is a number that uniquely identifies the risk location. The registration date and time is the date and time when the risk location is registered in the risk location information 112. The coordinates are data for identifying the risk location, and are represented by, for example, latitude and longitude data. The coordinates may include altitude data such as altitude in addition to latitude and longitude data. The passing direction is the direction (direction, angle) in which the vehicle 100 was facing when passing the trajectory intersection used to determine the risk location. The passing direction may be understood as the traveling direction (approaching direction) of the vehicle 100 when entering the trajectory intersection. In the example of FIG. 2, the passing direction of the vehicle 100 is specified as 0° northward, 90° eastward, 180° southward, and 270° westward.

[0027] Next, an example of a trajectory intersection will be described with reference to FIG. 3. As described above, a trajectory intersection is an intersection between the travel trajectory of the vehicle 100 and the travel trajectory of another vehicle. In this specification, a case where the vehicle 100 is traveling in an area where driving on the right side is mandatory will be described. In this case, the oncoming lane side of the vehicle 100 means the left side of the vehicle 100. The embodiment described in this specification is also applicable to a case where the vehicle 100 is traveling in an area where driving on the right side is mandatory. In this case, the oncoming lane side of the vehicle 100 means the right side of the vehicle 100.

[0028] In the example shown in FIG. 3(a), the position where the traveling trajectory 301a of the host vehicle 100 traveling straight north and the traveling trajectory 302a of the other vehicle OVA traveling straight west intersects is the trajectory intersection point CPa. Note that the timing (time) at which the host vehicle 100 passes through the trajectory intersection point CPa is different from the timing (time) at which the other vehicle OVA passes through the trajectory intersection point CPa, so there is no collision between the host vehicle 100 and the other vehicle OVA. 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 102 (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 103 (vehicle-to-vehicle communication module 114). Since the other vehicle OVa at the time of acquisition is a nearby vehicle that exists around the host vehicle 100, the other vehicle information may be understood as nearby 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 turns left intersects with the travel trajectory 302b of the other vehicle OVb that travels straight south is the trajectory intersection CPb. Note that the timing (time) at which the host vehicle 100 passes the trajectory intersection CPb is different from the timing (time) at which the other vehicle OVb passes the trajectory intersection CPb, so no collision occurs between the host vehicle 100 and the other vehicle OVb. Similarly to the travel trajectory 301a, 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 102 (GNSS module 113). The travel path 302b of the other vehicle OVb, like the travel path 302a, is included in the other vehicle information (surrounding vehicle information) acquired by the acquisition unit 110a via the inter-vehicle communication antenna 103 (inter-vehicle communication module 114).

[0030] The functions of the control device 106 can be realized by either hardware or software. For example, the functions of the control device 106 may be realized by the processing unit 110 (CPU) executing a driving assistance program and / or a 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). In the example of FIG. 1, the control device 106 is shown as a single element, but may be divided into two or more elements as necessary.

[0031] <Driving assistance processing> The driving assistance process of some embodiments will be described with reference to Figures 4 and 5. The driving assistance process shown in the flowchart of Figure 4 may be performed by the processing unit 110 in the control device 106 executing a driving assistance program read from the storage unit 111. The process of Figure 4 may be started, for example, in response to the driving assistance setting being turned on. The process of Figure 4 may be repeatedly executed until the driving assistance setting is turned off or the ignition of the vehicle 100 is turned off.

[0032] In step S401, the processing unit 110 (for example, the support unit 110b) determines whether or not a risk position RP exists in the target area TA ahead of the vehicle 100 by referring to the risk position information 112 stored in the storage unit 111. For example, the processing unit 110 can determine whether or not a risk position RP exists in the target area TA by comparing the current position of the vehicle 100 acquired by the acquisition unit 110a via the GNSS antenna 102 (GNSS module 113) with the coordinates (latitude, longitude) of each risk position RP included in the risk position information 112. FIG. 5(a) shows an example in which no risk position RP exists in the target area TA ahead of the vehicle 100, and FIG. 5(b) shows an example in which a risk position RP exists in the target area TA ahead of the vehicle 100.

[0033] The processing unit 110 transitions the process to step S402 when the risk position RP does not exist within the target area TA. The processing unit 110 (for example, the support unit 110b) sets the driving support intensity as the degree of driving support to a low level. On the other hand, the processing unit 110 transitions the process to step S403 when the risk position RP exists within the target area TA. The processing unit 110 (for example, the support unit 110b) sets the driving support intensity to a high level. The high level is set so that the degree of driving support (driving support intensity) is greater than the low level. For example, when the driving support intensity is at a high level, the operating conditions of the driving support may be more relaxed than when the driving support intensity is at a high level. That is, when the driving support intensity is at a high level, driving support may be more likely to occur than when the driving support intensity is at a low level. For example, even in a situation where driving assistance is not performed when the driving assistance intensity is low (for example, the vehicle 100 is in a specific driving state, the vehicle 100 is traveling on a specific road, etc.), driving assistance may be performed when the driving assistance intensity is high. Note that, although two types of driving assistance intensity, a low level and a high level, are exemplified in this embodiment, the number of driving assistance levels is not limited to two, and may be three or more.

[0034] In step S404, the processing unit 110 determines whether or not there is a surrounding vehicle RV. As described above, the surrounding vehicle RV is a vehicle that is currently present around the vehicle 100. For example, the processing unit 110 can determine that there is a surrounding vehicle RV when inter-vehicle communication can be performed via the inter-vehicle communication antenna 103 (inter-vehicle communication module 114). When the processing unit 110 determines that there is no surrounding vehicle RV, it transitions the process to step S401, and when the processing unit 110 determines that there is a surrounding vehicle RV, it transitions the process to step S405.

[0035] In step S405, the processing unit 110 (acquisition unit 110a) acquires the host vehicle information and the surrounding vehicle information. For example, the processing unit 110 acquires the surrounding vehicle information including the current position, speed, and traveling trajectory of the surrounding vehicle RV from the surrounding vehicle RV via the vehicle-to-vehicle communication antenna 103 (vehicle-to-vehicle communication module 114). The processing unit 110 also acquires the host vehicle information including the current position, speed, and traveling trajectory of the vehicle 100 via the sensor group 101 and the GNSS antenna 102 (GNSS module 113).

[0036] In step S406, the processing unit 110 (e.g., the support unit 110b) predicts the possibility of a collision between the vehicle 100 and the surrounding vehicle RV in the target area TA based on the host vehicle information and the surrounding vehicle information acquired in step S405. Then, in step S407, the processing unit 110 (e.g., the support unit 110b) determines whether or not there is a possibility of a collision between the vehicle 100 and the surrounding vehicle RV based on the prediction result in step S406. If the processing unit 110 determines that there is no possibility of a collision, it transitions the process to step S401, and if it determines that there is a possibility of a collision, it transitions the process to step S408.

[0037] In step S408, the processing unit 110 (for example, the support unit 110b) determines whether the speed of the surrounding vehicle RV is within a specified range based on the surrounding vehicle information acquired in step S405. The specified range may be set in advance by a lower limit speed value and an upper limit speed value related to the speed of the surrounding vehicle RV. If the speed of the surrounding vehicle RV is equal to or lower than the lower limit speed value of the specified range, the driver of the surrounding vehicle RV is likely to notice the vehicle 100 and decelerate the surrounding vehicle RV without colliding with the vehicle 100. In other words, the lower limit speed value of the specified range related to the speed of the surrounding vehicle RV may be set to a value that allows the surrounding vehicle RV to decelerate without colliding with the vehicle 100. In addition, if the speed of the surrounding vehicle RV is equal to or higher than the upper limit speed value of the specified range, the surrounding vehicle RV is likely not a vehicle traveling on the road into which the vehicle 100 enters, such as traveling on an expressway near the road into which the vehicle 100 enters. That is, the upper limit of the specified range regarding the speed of the nearby vehicle RV can be set to a value that makes it possible to distinguish whether the nearby vehicle RV is traveling on the road into which the vehicle 100 enters, or is traveling on an expressway near the road. In this way, by executing / suppressing driving assistance depending on whether the speed of the nearby vehicle RV is within the specified range, it is possible to reduce the annoyance felt by the driver of the vehicle 100 due to the driving assistance.

[0038] When the processing unit 110 determines in step S408 that the speed of the surrounding vehicle RV is not within a specified range, that is, outside the specified range, the processing unit 110 transitions the processing to step S401. That is, in the case of the method of FIG. 4, the processing unit 110 does not perform driving assistance for the vehicle 100 when the speed of the surrounding vehicle RV is outside the specified range, regardless of the collision possibility predicted in steps S406 to S407. On the other hand, when the processing unit 110 determines that the speed of the surrounding vehicle RV is within the specified range, the processing unit 110 transitions the processing to step S409. In step S409, the processing unit 110 (driving assistance unit 21c) performs driving assistance for the vehicle 100. As driving assistance for the vehicle 100, the processing unit 110 may notify the occupants of the vehicle 100 of the possibility of a collision by the alarm device 104, or perform a braking operation for the vehicle 100 by the braking device 105.

[0039] In this way, the control device 106 changes the degree of driving assistance (driving assistance intensity) of the vehicle 100 depending on whether or not the risk position RP exists within the target area TA in front of the vehicle 100.

[0040] <Risk location learning process> The risk position learning process will be described with reference to Figs. 6 to 11. Fig. 6 describes an example of a process for managing surrounding vehicles. The process shown in the flowchart of Fig. 6 is executed by the processing unit 110 in parallel with the flowchart of Fig. 4 according to a learning program read from the storage unit 111. The process of Fig. 6 may be started, for example, in response to the ignition of the vehicle 100 being turned on. The process of Fig. 6 may be repeatedly executed until the ignition of the vehicle 100 is turned off.

[0041] In step S601, the processing unit 110 (e.g., the acquisition unit 110a) determines whether or not another vehicle is present around the host vehicle 100. If it is determined that another vehicle is present around the host vehicle 100, the processing unit 110 transitions the process to step S602, and otherwise transitions the process to step S604. For example, the processing unit 110 may determine that another vehicle is present around the host vehicle 100 when vehicle-to-vehicle communication can be performed via the vehicle-to-vehicle communication antenna 103 (vehicle-to-vehicle communication module 114), similar to step S404 in FIG. 4.

[0042] In step S602, the processing unit 110 (e.g., the acquisition unit 110a) registers the other vehicle discovered in step S601 as a nearby vehicle. For example, the storage unit 111 may store a list of nearby vehicles, and the processing unit 110 may add information about the discovered nearby vehicle to this list. As described below, the nearby vehicles are used as targets of the intersection identification operation.

[0043] In step S603, the processing unit 110 (e.g., the acquisition unit 110a) starts acquiring surrounding vehicle information from the surrounding vehicles through vehicle-to-vehicle communication. As described above, the surrounding vehicle information may represent the vehicle speed, position, and driving trajectory of the surrounding vehicles. After starting to acquire the surrounding vehicle information in step S602, the processing unit 110 repeatedly acquires the surrounding vehicle information periodically (e.g., every 100 ms) until vehicle-to-vehicle communication with the surrounding vehicles is no longer possible.

[0044] After starting to acquire the surrounding vehicle information, in step S603, the processing unit 110 (e.g., the acquisition unit 110a) determines whether or not there is a vehicle that is no longer able to perform inter-vehicle communication among one or more registered surrounding vehicles. If such a vehicle is present, the processing unit 110 transitions the process to step S605, and otherwise transitions the process to step S601. For example, if a surrounding vehicle goes out of the communication range of inter-vehicle communication or is powered off, the vehicle 100 will no longer be able to perform inter-vehicle communication with the surrounding vehicle.

[0045] In step S605, the processing unit 110 (e.g., the acquisition unit 110a) cancels the registration of the nearby vehicle with which inter-vehicle communication is no longer possible. In other words, the processing unit 110 does not treat the vehicle with which inter-vehicle communication is no longer possible as a nearby vehicle. For example, the processing unit 110 deletes information about the nearby vehicle with which inter-vehicle communication is no longer possible from the list of nearby vehicles stored in the memory unit 111.

[0046] As described above, the processing unit 110 can periodically acquire the latest nearby vehicle information from other vehicles (that is, nearby vehicles) in the vicinity of the host vehicle 100 by executing the process in FIG.

[0047] Next, a method of learning a risk position using the surrounding vehicle information thus acquired will be described. As described with reference to FIG. 3(a), when the other vehicle is included in the range to the side of the host vehicle 100, if the host vehicle 100 and the other vehicle both move straight, these vehicles may collide. On the other hand, as described with reference to FIG. 3(b), when the other vehicle is included in the range in front of the host vehicle 100, if the host vehicle 100 turns left and the other vehicle moves straight, these vehicles may collide. In this way, the position where these vehicles may collide (i.e., the risk position) may differ depending on the position of the other vehicle relative to the host vehicle 100. Therefore, in some embodiments, the control device 106 learns the risk position differently depending on whether the surrounding vehicle is present in the range in front of the host vehicle 100 or in the range to the side.

[0048] With reference to FIG. 7, a range for selecting a risk position learning method will be described. The range 700 is located in front of the vehicle 100. The front of the vehicle 100 may be a range including the front of the vehicle 100. The range 700 may be a sector-shaped area as shown in FIG. 7, or may have another shape. The range 700 may be symmetrical with respect to the front direction of the vehicle 100. The central angle of the range 700 may be, for example, about 100 degrees to 110 degrees. The range 701 is located on the side of the vehicle 100. The side of the vehicle 100 may be a range including the diagonally forward direction of the vehicle 100. The range 701 may include a direction directly to the side of the vehicle 100. The range 701 may be a sector-shaped area as shown in FIG. 7, or may have another shape. In the example of FIG. 7, the ranges 701 are located on the right and left sides of the vehicle 100. The central angle of the range 701 may be, for example, about 80 degrees to 90 degrees. In the example of Fig. 7, a part of the range 700 and a part of the range 701 overlap. The central angle of this overlapping part may be, for example, about 10 degrees to 20 degrees. When a nearby vehicle is present in this overlapping part, this nearby vehicle becomes a target of both an intersection point identification operation (described later) for identifying the trajectory intersection CPa in Fig. 3(a) and an intersection point identification operation (described later) for identifying the trajectory intersection CPb in Fig. 3(b). Instead of the example of Fig. 7, the range 700 and the range 701 may simply be in contact with each other, or may be separated from each other.

[0049] When the surrounding vehicle is included in the range 701, the control device 106 may generate a trajectory intersection CPa by the host vehicle 100 going straight as shown in FIG. 3(a). Therefore, the control device 106 executes an intersection specifying operation so as to appropriately specify the trajectory intersection CPa. This operation will be described later with reference to FIG. 8 and FIG. 9. On the other hand, when the surrounding vehicle is included in the range 700, the control device 106 may generate a trajectory intersection CPb by the host vehicle 100 turning left as shown in FIG. 3(b). Therefore, the control device 106 executes an intersection specifying operation so as to appropriately specify the trajectory intersection CPb. This operation will be described later with reference to FIG. 10 and FIG. 11. The positions of the ranges 700 and 701 relative to the host vehicle 100 may be set in advance (for example, when the vehicle 100 is manufactured or when the software is updated) and stored in the storage unit 111.

[0050] FIG. 8 describes an example of processing for performing an intersection identification operation when a nearby vehicle RV (FIG. 9(a)) is present within a range 701 to the side of the vehicle 100. The processing shown in the flowchart of FIG. 8 is executed by the processing unit 110 in accordance with a learning program read from the memory unit 111. The processing of FIG. 8 may be executed for a nearby vehicle RV, for example, each time the nearby vehicle RV is newly registered in step S602 of FIG. 6. In the processing of FIG. 6, multiple other vehicles may be registered as nearby vehicles. The processing of FIG. 8 is executed for each of these multiple nearby vehicles.

[0051] In step S801, the processing unit 110 (e.g., its identification unit 110c) determines whether the surrounding vehicle RV is present within the range 701 to the side of the host vehicle 100. If it is determined that the surrounding vehicle RV is present within the range 701 to the side of the host vehicle 100, the processing unit 110 transitions the process to step S802, and otherwise repeats step S801. 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. 9(a), the surrounding vehicle RV is present within the range 701.

[0052] In step S802, the processing unit 110 (for example, the identification unit 110c) judges whether the predicted path of the host vehicle 100 and the predicted path of the surrounding vehicle RV intersect. If it is judged that these predicted paths intersect, the processing unit 110 transitions the process to step S803, and otherwise repeats step S802. The predicted path may be a half line extending from the vehicle to the front. In the example shown in FIG. 9(a), the predicted path 900 of the host vehicle 100 and the predicted path 901 of the surrounding vehicle RV intersect. The intersection of the predicted path 900 of the host vehicle 100 and the predicted path 901 of the surrounding vehicle RV is represented as a predicted intersection 902. The predicted path 900 of the host vehicle 100 may be determined based on host vehicle information (specifically, the current position and the driving trajectory). The processing unit 110 may acquire the latest host vehicle information at this point. The predicted course 901 of the surrounding vehicle RV may be determined based on the latest surrounding vehicle information (specifically, the current position and traveling trajectory).

[0053] In step S803, the processing unit 110 (for example, the identification unit 110c) sets a judgment area using the predicted intersection 902 as a reference position, and stores the reference position and the judgment area in the storage unit 111. The judgment area may be an area used for determining the start of execution of an intersection identification operation described later. With reference to FIG. 9(a), an example of the judgment area 903 set using the predicted intersection 902 as a reference position will be described. The judgment area 903 may be a square centered on the predicted intersection 902 and including sides parallel to the predicted path 900 of the vehicle 100. One side of the square may have a length equivalent to three lanes (for example, about 9 m to 11 m). The judgment area 903 is a planar area including the predicted intersection 902. Alternatively, the judgment area 903 may have another shape.

[0054] In the example of FIG. 9(a), the determination area 903 is a planar area. Alternatively, as shown in FIG. 9(b), the determination area 903 may be a linear area. In the example of FIG. 9(b), the determination area 903 is an L-shaped area that is centered on the predicted intersection 902 and includes a side parallel to the predicted path 900 of the vehicle 100, and is configured by a side far from the vehicle 100 and a side on the oncoming lane side (the left side in this example). The position of the determination area 903 relative to the reference position may be set in advance (for example, when the vehicle 100 is manufactured or when the software is updated) and stored in the storage unit 111.

[0055] In step S806, the processing unit 110 (for example, the identification unit 110c) determines whether or not both the surrounding vehicle RV and the host vehicle 100, which are the subject of the processing in FIG. 8, have passed through the judgment area 903. The processing unit 110 transitions the processing to step S808 when it is determined that both the surrounding vehicle RV and the host vehicle 100 have passed through the judgment area 903, and transitions the processing to step S807 otherwise. This determination may be made based on the latest host vehicle information (specifically, the current position and the traveling trajectory) and the latest surrounding vehicle information (specifically, the current position and the traveling trajectory). Passing through the judgment area 903 may mean that the current position of the vehicle comes to have a common portion with the judgment area 903 and then no longer has a common portion with the judgment area 903.

[0056] In step S808, the processing unit 110 (for example, the identification unit 110c) executes an intersection identifying operation. Specifically, the processing unit 110 identifies an intersection (i.e., a trajectory intersection) between the travel trajectory of the host vehicle 100 after the judgment area is set in step S803 and the travel trajectory of the surrounding vehicle RV. The intersection identifying operation may be performed based on the latest host vehicle information and the latest surrounding vehicle information. In this manner, the intersection identifying operation is performed based on the judgment area set with the predicted intersection 902 as the reference position. Therefore, the intersection identifying operation can be considered to be performed with the predicted intersection 902 as the reference position. In step S808, the travel trajectory of the host vehicle 100 and the travel trajectory of the surrounding vehicle RV may not have an intersection. In this case, even if the intersection identifying operation is performed, the trajectory intersection is not identified.

[0057] In step S809, the processing unit 110 (for example, its update unit 110d) updates the risk location information 112 based on the trajectory intersection identified by the intersection identification operation in step S808. For example, when the risk location information 112 does not include a risk location near (for example, within 20 m) a trajectory intersection, the processing unit 110 may include this trajectory intersection as a new risk location in the risk location information 112. When the risk location information 112 includes a risk location near (for example, within 20 m) a trajectory intersection, the processing unit 110 may correct this risk location based on the trajectory intersection. This correction may be, for example, a weighted average of the risk location and the trajectory intersection. The weight of the risk location may be the number of trajectory intersections used to determine the risk location. When updating the risk location information 112, the processing unit 110 also registers information of each column shown in FIG. 2. If a trajectory intersection is not identified by the intersection identifying operation (that is, if the travel trajectory of the host vehicle 100 and the travel trajectory of the surrounding vehicle RV do not intersect), step S809 is skipped (the risk position information 112 is not updated).

[0058] In step S810, the processing unit 110 (for example, the identification unit 110c) deletes the reference position and the determination area (the reference position and the determination area stored in step S803) that are no longer necessary due to the end of the intersection identification operation from the storage unit 111. This prevents the capacity of the storage unit 111 from being consumed by unnecessary information.

[0059] If it is determined in step S806 that at least one of the surrounding vehicle RV and the host vehicle 100 has not passed through the judgment area 903, step S807 is executed. In step S807, the processing unit 110 (for example, the identification unit 110c) determines whether the host vehicle 100 has moved a predetermined distance (for example, 30 m) or more from the reference position stored in step S803. If it is determined that the host vehicle 100 has moved a predetermined distance or more from the reference position, the processing unit 110 transitions the processing to step S810, and otherwise transitions the processing to step S804. If the host vehicle 100 has moved a predetermined distance or more from the reference position before both the surrounding vehicle RV and the host vehicle 100 have passed through the judgment area 903, for example, there is a possibility that the surrounding vehicle RV or the host vehicle 100 has turned around without passing through the judgment area 903. Therefore, the processing unit 110 ends the processing without performing the intersection identification operation. In this case as well, in step S810, the processing unit 110 (eg, the specifying unit 110c) deletes from the storage unit 111 the reference positions and determination regions that are no longer necessary.

[0060] If it is determined in step S807 that the host vehicle 100 is not at a distance greater than a predetermined distance from the reference position, step S804 is executed. In step S804, the processing unit 110 (for example, the identification unit 110c) re-determines the predicted intersection 902 and determines whether the position has changed. If it is determined that the position of the predicted intersection 902 has changed, the processing unit 110 transitions the process to step S805, and otherwise transitions the process to step S806. For example, when a vehicle (host vehicle 100 or surrounding vehicle RV) changes its position within a lane or changes lanes, the position of the predicted intersection 902 may change. Since surrounding vehicle information is repeatedly acquired, the processing unit 110 can detect such a change in the position of the predicted intersection 902. Therefore, in step S805, the processing unit 110 (for example, the identification unit 110c) updates the reference position stored in the storage unit 111 based on the newly acquired surrounding vehicle information, and accordingly updates the judgment area stored in the storage unit 111. As a result, the determination in step S806 is made based on the updated determination area. Also, the determination in step S807 is made based on the updated reference position. If the predicted intersection 902 cannot be re-determined in step S804 (for example, if the predicted path 900 of the vehicle 100 and the predicted path 901 of the surrounding vehicle RV no longer intersect), the most recently determined reference position and determination area are maintained.

[0061] In the method of Fig. 8, unless it is determined in step S801 that a nearby vehicle is present within the range 701, it is determined in step S802 that the predicted path of the nearby vehicle and the predicted path of the vehicle 100 intersect, and it is determined in step S806 that these vehicles have passed through the judgment area, the intersection identification operation of step S808 is not executed. This makes it possible to prevent the risk position information from being inappropriately updated. When the registration of the nearby vehicle that is the target of the processing of Fig. 8 is cancelled by step S605 of Fig. 6, the processing unit 110 may stop the processing of Fig. 8.

[0062] According to the method of FIG. 8, when multiple surrounding vehicles are present within the range 701 to the side of the vehicle 100, an individual reference position is used for each of the multiple surrounding vehicles. Specifically, the method of FIG. 8 is executed for each of the multiple surrounding vehicles individually. As a result, a predicted intersection between the predicted path of the vehicle 100 and the predicted path of the surrounding vehicle is also determined for each of the multiple surrounding vehicles. As a result, an individual judgment area is set for each of the multiple surrounding vehicles based on the individual reference position. This makes it possible to appropriately estimate the position of an intersection where multiple lanes intersect, etc.

[0063] FIG. 10 describes an example of processing for performing an intersection identification operation when a nearby vehicle RV (FIG. 11(a)) is present within a range 700 ahead of the host vehicle 100. The processing shown in the flowchart of FIG. 10 is executed by the processing unit 110 in accordance with a learning program read from the storage unit 111. The processing of FIG. 10 may be started, for example, in response to the ignition of the vehicle 100 being turned on. The processing of FIG. 10 may be repeatedly executed until the ignition of the vehicle 100 is turned off.

[0064] In step S1001, the processing unit 110 (for example, the identification unit 110c) judges whether the host vehicle 100 accelerates or stops after decelerating to a threshold value or less. If it is judged that the host vehicle 100 accelerates or stops after decelerating to a threshold value or less, the processing unit 110 transitions the process to step S1002, and otherwise repeats step S1001. This judgment may be made based on the vehicle speed and acceleration of the host vehicle 100 included in the latest host vehicle information. The threshold used in step S1001 is a value below which the vehicle speed after decelerating to turn (for example, turn left or turn right) is lowered, and may be, for example, 20 km per hour. The position where the host vehicle 100 accelerates or stops after decelerating to a threshold value or less is represented as a turning preparation position 1101 (FIG. 11(a)). Note that the host vehicle 100 may accelerate or stop after decelerating to a threshold value or less even if it does not turn. Even in this case, the processing unit 110 detects the turning preparation position 1101 and executes the processes from step S1002 onwards.

[0065] In step S1002, the processing unit 110 (for example, the identification unit 110c) sets a judgment area using the turning preparation position 1101 as a reference position, and stores the reference position and the judgment area in the storage unit 111. The judgment area may be an area used to determine the start of execution of an intersection identification operation described later. With reference to FIG. 11(a), an example of the judgment area 1102 set using the turning preparation position 1101 as a reference position will be described. The judgment area 1102 may be a square centered on the left front position of the turning preparation position 1101 and including a side parallel to the predicted path 900 of the host vehicle 100. One side of the square may have a length equivalent to, for example, three lanes (for example, about 9 m to 11 m). The judgment area 1102 is a planar area. Alternatively, the judgment area 1102 may have another shape. For example, the judgment area 1102 may be a rectangle with a side parallel to the predicted path 900 of the host vehicle 100 as the long side. The processing unit 110 sets a determination region 1102 so as to include a turning preparation position 1101 (i.e., a reference position) and to offset the determination region 1102 toward the oncoming lane (the left side in the example of FIG. 11(a)) relative to the vehicle 100 in a direction perpendicular to the predicted path 900 of the vehicle 100. This makes it possible to appropriately identify a trajectory intersection that occurs when the vehicle 100 turns left.

[0066] In the example of FIG. 11(a), the determination area 1102 is a planar area. Alternatively, as shown in FIG. 11(b), the determination area 1102 may be a linear area. In the example of FIG. 11(b), the determination area 1102 is a U-shaped area centered on the left front position of the turning preparation position 1101 and configured by three sides of a square including sides parallel to the predicted path 900 of the vehicle 100, other than the side farthest from the vehicle 100. The position of the determination area 1102 relative to the reference position may be set in advance (for example, when the vehicle 100 is manufactured or when the software is updated) and stored in the storage unit 111.

[0067] In step S1003, the processing unit 110 (e.g., its identification unit 110c) identifies a surrounding vehicle RV present within the range 700 in front of the host vehicle 100 as a target vehicle for subsequent processing. If there is no surrounding vehicle RV within the range 700, no target vehicle is identified. If there are multiple surrounding vehicles RV within the range 700, all of these multiple surrounding vehicles RV are identified as target vehicles. This identification 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. 11(a), one surrounding vehicle RV exists within the range 700.

[0068] In step S1004, the processing unit 110 (e.g., the identification unit 110c) determines whether the host vehicle 100 has passed through the judgment area 1102. If it is determined that the host vehicle 100 has passed through the judgment area 1102, the processing unit 110 transitions the process to step S1006, and otherwise transitions the process to step S1005. This determination may be made based on the latest host vehicle information (specifically, the current position and traveling trajectory). Passing through the judgment area 1102 may mean that the current position of the vehicle has a common portion with the judgment area 1102 and then no longer has a common portion with the judgment area 1102.

[0069] In step S1006, the processing unit 110 (for example, the identification unit 110c) executes an intersection identifying operation for each of the vehicles that have passed through the judgment area 1102 among all the target vehicles identified in S1003. Specifically, the processing unit 110 identifies an intersection (i.e., a trajectory intersection) between the traveling trajectory of the host vehicle 100 after the judgment area is set in step S1002 and the traveling trajectory of the target vehicle. The intersection identifying operation may be performed based on the latest host vehicle information and the latest surrounding vehicle information. In this manner, the intersection identifying operation is performed based on the judgment area set with the turning preparation position 1101 as the reference position. Therefore, the intersection identifying operation may be considered to be performed with the turning preparation position 1101 as the reference position. In step S1006, the traveling trajectory of the host vehicle 100 and the traveling trajectory of the surrounding vehicle RV may not have an intersection. In this case, even if the intersection identifying operation is performed, the trajectory intersection is not identified.

[0070] In step S1007, the processing unit 110 (for example, the update unit 110d) updates the risk position information 112 based on the trajectory intersection identified by the intersection identification operation in step S1007. The process of step S1007 may be the same as the process of step S809, so a duplicated description will be omitted.

[0071] If there is no surrounding vehicle RV identified as a target vehicle in step S1004, or if there is no target vehicle that has passed through the determination area 1102, steps S1006 and S1007 are skipped.

[0072] The process of step S1008 may be similar to the process of step S810, and therefore a duplicated description will be omitted.

[0073] If it is determined in step S1004 that the host vehicle 100 has not passed through the judgment area 1102, step S1005 is executed. In step S1005, the processing unit 110 (for example, the identification unit 110c) determines whether the host vehicle 100 has moved a predetermined distance (for example, 30 m) or more from the reference position (i.e., the turning preparation position 1101) stored in step S1002. If it is determined that the host vehicle 100 has moved a predetermined distance or more from the reference position, the processing unit 110 transitions the processing to step S1008, and otherwise transitions the processing to step S1003. If the host vehicle 100 has moved a predetermined distance or more from the reference position before passing through the judgment area 1102, for example, there is a possibility that the host vehicle 100 has turned without passing through the judgment area 1102. Therefore, the processing unit 110 ends the processing without performing the intersection identification operation. Also in this case, in step S1008, the processing unit 110 (for example, the specifying unit 110c) deletes from the storage unit 111 the reference positions and determination regions that are no longer necessary.

[0074] If it is determined in step S1005 that the vehicle 100 is not at least a predetermined distance away from the reference position, step S1003 is executed again. In step S1003, the processing unit 110 (e.g., the identification unit 110c) identifies the surrounding vehicle RV that is newly included in the range 700 as a target vehicle for subsequent processing. Even if a new surrounding vehicle is present in the range 700, the processing unit 110 does not execute step S1002 (i.e., does not set a new judgment area 1102) until the judgment area 1102 is set in step S1002 and deleted in step S1008.

[0075] 10, the intersection identification operation in step S1006 is not executed unless it is determined in step S1001 that the vehicle 100 has accelerated again or stopped temporarily, and it is determined in step S1004 that the surrounding vehicle RV and the vehicle 100 present within the range 700 have passed through the judgment area. This makes it possible to prevent the risk position information from being inappropriately updated.

[0076] 10, when multiple surrounding vehicles are present within the range 700 ahead of the vehicle 100, a common reference position (i.e., turning preparation position 1101) is used for the multiple surrounding vehicles. As a result, a common judgment area is set for each of the multiple surrounding vehicles based on the common reference position. This allows the position of the intersection when the vehicle 100 turns to the oncoming lane (for example, when turning left) to be appropriately estimated.

[0077] In the above-described driving assistance method, the surrounding vehicle RV is set as a target for learning the risk position based on the fact that the surrounding vehicle RV is located within the range 700 or 701 in Fig. 7. The processing unit 110 may determine whether or not to set the surrounding vehicle RV as a target for learning the risk position based on other information. With reference to Fig. 12, an example of a method for determining the surrounding vehicle RV as a target for learning the risk position will be described.

[0078] The processing unit 110 may determine whether the surrounding vehicle RV is to be a target for learning the risk position, further based on a rotation angle 1203 of the course vector 1202 of the surrounding vehicle RV relative to the course vector 1201 of the host vehicle 100. The course vector 1201 may be a unit vector facing the traveling direction of the vehicle. For the sake of explanation, the rotation angle 1203 is positive in the clockwise direction and negative in the counterclockwise direction. The processing unit 110 can determine the approach direction of the surrounding vehicle RV based on the direction of the surrounding vehicle RV relative to the host vehicle 100 and the rotation angle 1203 of the course vector 1202 of the surrounding vehicle RV relative to the course vector 1201 of the host vehicle 100.

[0079] Even if the surrounding vehicle RV is included in the range 700 in front of the host vehicle 100, if the surrounding vehicle RV is traveling in the same direction as the host vehicle 100 or traveling to the right or left of the host vehicle 100, it is considered that there is no possibility of a collision between the host vehicle 100 and the surrounding vehicle RV. Therefore, the processing unit 110 may treat the surrounding vehicle RV as a target for learning the risk position in the process of FIG. 4 when the surrounding vehicle RV is within the range 700 in front of the host vehicle 100 and the rotation angle 1203 is within a predetermined range (for example, 160° to 200°).

[0080] Even if the surrounding vehicle RV is included in the range 701 on the right side of the host vehicle 100, if the surrounding vehicle RV is traveling in the same direction as the host vehicle 100 or in the opposite direction, or traveling to the right of the host vehicle 100, it is considered that there is no possibility of a collision between the host vehicle 100 and the surrounding vehicle RV. Therefore, the processing unit 110 may treat the surrounding vehicle RV as a target for learning the risk position in the process of FIG. 4 when the surrounding vehicle RV is included in the range 701 on the right side of the host vehicle 100 and the rotation angle 1203 is included in a predetermined range (for example, −110° to −70°).

[0081] Even if the surrounding vehicle RV is included in the range 701 on the left side of the host vehicle 100, if the surrounding vehicle RV is traveling in the same direction as the host vehicle 100 or in the opposite direction, or traveling to the left of the host vehicle 100, it is considered that there is no possibility of a collision between the host vehicle 100 and the surrounding vehicle RV. Therefore, the processing unit 110 may treat the surrounding vehicle RV as a target for learning the risk position in the processing of FIG. 4 when the surrounding vehicle RV is within the range 701 on the left side of the host vehicle 100 and the rotation angle 1203 is within a predetermined range (for example, 70° to 110°).

[0082] According to the above-described embodiment, since an appropriate intersection identifying operation is performed according to the positions of the surrounding vehicles, risk position information can be determined with high accuracy. As a result, driving assistance for the host vehicle 100 can be performed appropriately.

[0083] <Summary of the embodiment> [Item 1] A driving assistance device (106), A storage means (111) for storing risk position information (112) representing a position where a host vehicle (100) equipped with the driving assistance device may collide with another vehicle (RV); an assistance means (110b) for providing driving assistance to the host vehicle based on the risk position information; An acquisition means (111a) for acquiring surrounding vehicle information indicating a vehicle speed, a position, and a traveling path of the surrounding vehicle from surrounding vehicles existing around the host vehicle by vehicle-to-vehicle communication; A specifying means (110c) for executing an intersection specifying operation for specifying an intersection (CPa, CPb) between the travel path of the host vehicle and the travel path of the surrounding vehicle; and an update means (110d) for updating the risk location information based on the intersection identified by the intersection identifying operation, The identification means is When the surrounding vehicle is present within a first range (700) ahead of the host vehicle, the intersection identification operation is executed with a position where the host vehicle accelerates after decelerating to a threshold value or below, or a position where the host vehicle stops, as a first reference position (1101); A driving assistance device that, when the surrounding vehicle is present within a second range (701) to the side of the vehicle, executes the intersection identification operation using the intersection between the predicted path (900) of the vehicle and the predicted path (901) of the surrounding vehicle as a second reference position (902). According to this item, risk location information can be appropriately updated, and as a result, driving assistance can be appropriately provided. [Item 2] The identification means is When a plurality of surrounding vehicles are present within the first range, the first reference position is used common to the plurality of surrounding vehicles; 2. The driving assistance device according to item 1, wherein, when a plurality of peripheral vehicles are present within the second range, an individual second reference position is used for each of the plurality of peripheral vehicles. This item allows risk location information to be updated more appropriately. [Item 3] The identification means is When the surrounding vehicle is present within the first range, a first judgment area (1102) is set for the first reference position, and when both the surrounding vehicle and the host vehicle have passed through the first judgment area, the intersection identification operation is executed; 3. The driving assistance device according to claim 1, further comprising: a second judgment area (903) set for the second reference position when the surrounding vehicle is present within the second range; and when both the surrounding vehicle and the host vehicle have passed through the second judgment area, the intersection identification operation is performed. This item allows risk location information to be updated more appropriately. [Item 4] The driving assistance device according to item 3, wherein the identification means sets the first judgment area so as to include the first reference position and to be offset toward an oncoming lane relative to the host vehicle in a direction perpendicular to the predicted path of the host vehicle. This item allows risk location information to be updated more appropriately. [Item 5] 5. The driving assistance device according to claim 3, wherein the identification means sets the second judgment region so as to include the second reference position. This item allows risk location information to be updated more appropriately. [Item 6] The acquisition means repeatedly acquires the surrounding vehicle information from the surrounding vehicles, The identification means is When a new surrounding vehicle different from the surrounding vehicle is present within the first range and the first judgment area has been set, the first judgment area is not newly set, 6. The driving assistance device according to any one of claims 3 to 5, wherein, when the surrounding vehicle is present within the second range, the second reference position is updated based on newly acquired surrounding vehicle information, and the second judgment area is updated accordingly. This item allows risk location information to be updated more appropriately. [Item 7] The identification means is After the first judgment area is set, when the intersection identifying operation is completed or when the host vehicle is moved away from the first reference position by a predetermined distance or more, the first judgment area is deleted; 7. The driving assistance device according to any one of claims 3 to 6, wherein after the second judgment area is set, when the intersection identification operation is completed or when the host vehicle moves away from the updated second reference position by a predetermined distance or more, the second judgment area is deleted. According to this item, the capacity of the storage unit can be used appropriately. [Item 8] A driving assistance method executed by a vehicle (100), comprising: The host vehicle includes a storage means (111) for storing risk position information (112) representing a position where the host vehicle may collide with another vehicle (RV), and the driving assistance method includes: An assistance step (S409) of providing driving assistance to the host vehicle based on the risk position information; An acquisition step (S603) of acquiring surrounding vehicle information indicating a vehicle speed, a position, and a traveling trajectory of the surrounding vehicle from a surrounding vehicle (RV) existing around the host vehicle by vehicle-to-vehicle communication; A determination step (S808, S1006) of performing an intersection determination operation for determining an intersection (CPa, CPb) between the travel trajectory of the host vehicle and the travel trajectory of the surrounding vehicle; An update process (S809, S1007) for updating the risk location information based on the intersection identified by the intersection identifying operation, The identifying step includes: When the surrounding vehicle is present within a first range (700) ahead of the host vehicle, the node identification operation is executed using a position where the host vehicle accelerates after decelerating to a threshold value or below, or a position where the host vehicle stops, as a first reference position (1101); and executing the intersection identification operation using an intersection between a predicted path (900) of the vehicle and a predicted path (901) of the surrounding vehicle as a second reference position (902) when the surrounding vehicle is present within a second range (701) to the side of the vehicle. According to this item, risk location information can be appropriately updated, and as a result, driving assistance can be appropriately provided. [Item 9] A program for causing a computer mounted on a host vehicle (100) to execute each step of a driving assistance method, the host vehicle including a storage means (111) for storing risk position information (112) representing a position where the host vehicle may collide with another vehicle (RV), and the driving assistance method includes: An assistance step (S409) of providing driving assistance to the host vehicle based on the risk position information; An acquisition step (S603) of acquiring surrounding vehicle information indicating a vehicle speed, a position, and a traveling trajectory of the surrounding vehicle from a surrounding vehicle (RV) existing around the host vehicle by vehicle-to-vehicle communication; A determination step (S808, S1006) of performing an intersection determination operation for determining an intersection (CPa, CPb) between the travel trajectory of the host vehicle and the travel trajectory of the surrounding vehicle; An update process (S809, S1007) for updating the risk location information based on the intersection identified by the intersection identifying operation, The identifying step includes: When the surrounding vehicle is present within a first range (700) ahead of the host vehicle, the node identification operation is executed using a position where the host vehicle accelerates after decelerating to a threshold value or below, or a position where the host vehicle stops, as a first reference position (1101); and when the surrounding vehicle is present within a second range (701) to the side of the vehicle, executing the intersection identifying operation using an intersection between a predicted path (900) of the vehicle and a predicted path (901) of the surrounding vehicle as a second reference position (902). According to this item, risk location information can be appropriately updated, and as a result, driving assistance can be appropriately provided.

[0084] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0085] 100: vehicle, 101: sensor group, 102: GNSS antenna, 103: vehicle-to-vehicle communication antenna, 104: notification device, 105: braking device, 106: control device

Claims

1. A driving assistance device, A storage means for storing risk position information indicating a position where a vehicle equipped with the driving support device may collide with another vehicle; an assistance means for providing driving assistance to the host vehicle based on the risk position information; an acquisition means for acquiring surrounding vehicle information indicating a vehicle speed, a position, and a traveling path of the surrounding vehicle from surrounding vehicles present around the host vehicle through vehicle-to-vehicle communication; a specifying means for executing an intersection specifying operation for specifying an intersection between a travel path of the host vehicle and a travel path of the surrounding vehicle; and an update means for updating the risk position information based on the intersections identified by the intersection identifying operation, The identification means is When the surrounding vehicle is present within a first range ahead of the host vehicle, the intersection identifying operation is executed using a position where the host vehicle has decelerated to a threshold value or below and then accelerated or a position where the host vehicle has stopped as a first reference position; A driving assistance device that, when the surrounding vehicle is present within a second range to the side of the vehicle, executes the intersection identification operation using an intersection between the predicted path of the vehicle and the predicted path of the surrounding vehicle as a second reference position.

2. The identification means is When a plurality of surrounding vehicles are present within the first range, the first reference position is used common to the plurality of surrounding vehicles; The driving assistance device according to claim 1 , wherein, when a plurality of peripheral vehicles are present within the second range, an individual second reference position is used for each of the plurality of peripheral vehicles.

3. The identification means is when the surrounding vehicle is present within the first range, a first determination area is set with respect to the first reference position, and when both the surrounding vehicle and the host vehicle have passed through the first determination area, the intersection identifying operation is executed; 2. The driving assistance device according to claim 1, wherein when the surrounding vehicle is present within the second range, a second judgment area is set for the second reference position, and when both the surrounding vehicle and the host vehicle pass through the second judgment area, the intersection identification operation is performed.

4. 4. The driving assistance device according to claim 3, wherein the specifying means sets the first determination area so as to include the first reference position and to be offset toward an oncoming lane relative to the host vehicle in a direction perpendicular to a predicted path of the host vehicle.

5. The driving assistance device according to claim 3 , wherein the specifying means sets the second determination region so as to include the second reference position.

6. The acquisition means repeatedly acquires the surrounding vehicle information from the surrounding vehicles, The identification means is When a new surrounding vehicle different from the surrounding vehicle is present within the first range and the first determination area has been set, the first determination area is not newly set, 4. The driving assistance device according to claim 3, wherein when the surrounding vehicle is present within the second range, the second reference position is updated based on newly acquired surrounding vehicle information, and the second judgment area is updated accordingly.

7. The identification means is After the first judgment area is set, when the intersection identifying operation is completed or when the host vehicle is moved away from the first reference position by a predetermined distance or more, the first judgment area is deleted; 4. The driving assistance device according to claim 3, wherein after the second judgment area is set, when the intersection identification operation is completed, or when the host vehicle moves away from the updated second reference position by a predetermined distance or more, the second judgment area is deleted.

8. A driving assistance method executed by a vehicle, comprising: The host vehicle includes a storage means for storing risk position information indicating a position where the host vehicle may collide with another vehicle, and the driving assistance method includes: an assistance step of providing driving assistance to the host vehicle based on the risk position information; an acquisition step of acquiring surrounding vehicle information indicating a vehicle speed, a position, and a traveling trajectory of the surrounding vehicle from surrounding vehicles existing around the host vehicle through vehicle-to-vehicle communication; a specifying step of executing an intersection specifying operation for specifying an intersection between a travel trajectory of the host vehicle and a travel trajectory of the surrounding vehicle; An updating step of updating the risk location information based on the intersections identified by the intersection identifying operation, The identifying step includes: When the surrounding vehicle is present within a first range ahead of the host vehicle, the node identifying operation is executed using a position where the host vehicle decelerates to a threshold value or below and then accelerates, or a position where the host vehicle stops, as a first reference position; A driving assistance method comprising: when the surrounding vehicle is present within a second range to the side of the vehicle, executing the intersection identification operation using an intersection between the predicted path of the vehicle and the predicted path of the surrounding vehicle as a second reference position.

9. A program for causing a computer mounted on a vehicle to execute each step of a driving assistance method, the vehicle including a storage means for storing risk position information indicating a position where the vehicle may collide with another vehicle, the driving assistance method including: an assistance step of providing driving assistance to the host vehicle based on the risk position information; an acquisition step of acquiring surrounding vehicle information indicating a vehicle speed, a position, and a traveling trajectory of the surrounding vehicle from surrounding vehicles existing around the host vehicle through vehicle-to-vehicle communication; a specifying step of executing an intersection specifying operation for specifying an intersection between a travel trajectory of the host vehicle and a travel trajectory of the surrounding vehicle; An updating step of updating the risk location information based on the intersections identified by the intersection identifying operation, The identifying step includes: When the surrounding vehicle is present within a first range ahead of the host vehicle, the node identifying operation is executed using a position where the host vehicle decelerates to a threshold value or below and then accelerates, or a position where the host vehicle stops, as a first reference position; and when the surrounding vehicle is present within a second range to the side of the vehicle, executing the intersection identification operation using an intersection between the predicted path of the vehicle and the predicted path of the surrounding vehicle as a second reference position.

Images