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 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 become more active. To achieve this, efforts are being focused on research and development into preventive safety technologies to further improve traffic safety and convenience. Devices that provide driving assistance to prevent collisions with other vehicles (surrounding vehicles) without using map information are known. Patent Document 1 discloses a driving assistance device that registers in a storage unit position information of an intersection where the driving path of the vehicle and the driving path of another vehicle intersect, and provides driving assistance to the vehicle when passing through the intersection again. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7054636 Summary of the Invention [Problem to be solved by the invention]

[0004] A driving assistance device may identify a risk location where the host vehicle may collide with another vehicle based on the travel trajectory of the host vehicle and the travel trajectory of another vehicle, and use the risk location for driving assistance. However, even if an intersection is actually present in the direction of travel of the host vehicle, driving assistance using the risk location cannot be performed until the intersection is identified as a risk location. Some aspects of the present disclosure aim to provide an advantageous technology for appropriately providing driving assistance for the host vehicle, which in turn contributes to the development of a sustainable transportation system. [Means for solving the problem]

[0005] According to some embodiments, there is provided a driving assistance device, wherein a vehicle equipped with the driving assistance device is in a state of collision with another vehicle. risk and a notification means for issuing a notification to an occupant of the host vehicle based on a 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 trajectory of the host vehicle based on the host vehicle information, determines a predicted trajectory of the peripheral vehicle based on the peripheral vehicle information, and determines an evaluation distance for evaluating an approach situation between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle. When the evaluation distance is not included within a predetermined range, the prediction means predicts that there is no possibility of a collision between the host vehicle and the peripheral vehicle. The prediction means determines a prediction accuracy of the predicted trajectory of the host vehicle based on a vehicle speed and a yaw rate of the host vehicle, determines a prediction accuracy of the predicted trajectory of the peripheral vehicle based on a vehicle speed and a yaw rate of the peripheral vehicle, and selects a method of determining the evaluation distance from a plurality of candidate determination methods based on the prediction accuracy of the predicted trajectory of the host vehicle, a radius of curvature of the predicted trajectory of the host vehicle, the prediction accuracy of the predicted trajectory of the peripheral vehicle, and a radius of curvature of the predicted trajectory of the peripheral vehicle. , a driving assistance device is provided. [Effects of the Invention]

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

[0007] [Figure 1] FIG. 1 is a block diagram illustrating an example configuration of a vehicle according to some embodiments. [Figure 2] FIG. 10 illustrates an example of risk location information according to some embodiments. [Figure 3] 10A and 10B are schematic diagrams illustrating examples of trajectory intersections according to some embodiments. [Figure 4] FIG. 1 is a flow diagram illustrating an example of a method for registering nearby vehicles according to some embodiments. [Figure 5] FIG. 1 is a flow diagram illustrating an example method for determining risk locations according to some embodiments. [Figure 6] FIG. 10 is a schematic diagram illustrating an example of a range that includes surrounding vehicles according to some embodiments. [Figure 7] FIG. 10 is a flow diagram illustrating an example of a driving assistance operation regarding a nearby vehicle to the side, according to some embodiments. [Figure 8] 10A and 10B are schematic diagrams illustrating an example of an operation for determining an evaluation distance related to a nearby vehicle on the side according to some embodiments. [Figure 9] FIG. 10 is a diagram illustrating an example of a correspondence table between yaw angular acceleration and reliability according to some embodiments. [Figure 10] 10A and 10B are schematic diagrams illustrating an example of an operation for determining an evaluation distance related to a nearby vehicle on the side according to some embodiments. [Figure 11] 10A and 10B are schematic diagrams illustrating an example of a driving assistance 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 driving assistance operation regarding a nearby vehicle to the side according to some embodiments. [Figure 13] FIG. 10 is a flow diagram illustrating an example of a driving assistance operation regarding a nearby vehicle ahead according to some embodiments. [Figure 14] 10A and 10B are schematic diagrams illustrating an example of an operation for determining an evaluation distance related to a nearby vehicle ahead according to some embodiments. [Figure 15] 10A and 10B are schematic diagrams illustrating an example of an operation for determining an evaluation distance related to a nearby vehicle ahead according to some embodiments. [Figure 16] 10A and 10B are schematic diagrams illustrating an example of a driving assistance operation regarding a nearby vehicle ahead according to some embodiments. [Figure 17] 10A and 10B are schematic diagrams illustrating an example of a method for determining a nearby vehicle to be determined according to some embodiments. [Figure 18] FIG. 10 is a schematic diagram illustrating an example of a notification method according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any desired manner. Furthermore, the same reference numerals are used to designate identical or similar components, and redundant descriptions will be omitted.

[0009] <Vehicle configuration example> With reference to FIG. 1 , an example 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 Global Navigation Satellite System (GNSS) antenna 103, a vehicle-to-vehicle communication antenna 104, a notification device 105, a braking device 106, turn signals 107, and a control device 108. Although FIG. 1 illustrates the components referred to in the following description, the vehicle 100 may include other components for operating as a vehicle, such as a drive unit and a transmission. Additionally or alternatively, 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, a driver of the vehicle 100 may be simply referred to as a driver.

[0010] The control device 108 controls the overall operation of the vehicle 100. As will be described later, the control device 108 performs driving assistance for the vehicle 100 in which the control device 108 is installed. Therefore, the control device 108 may be referred to as a driving assistance device. The driving assistance provided by the control device 108 may be collision prevention assistance for preventing (reducing) collisions with other vehicles. In some embodiments, the control device 108 is capable of performing collision prevention assistance without using map information. In the following description, the vehicle 100 may be referred to as the host vehicle 100 to easily distinguish it from other vehicles. Furthermore, a vehicle different from the vehicle 100 may be referred to as another vehicle. Of the other vehicles, a vehicle currently present around the host vehicle 100 may be referred to as a surrounding vehicle. A 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, etc. The sensor group 101 may also include external detection sensors such as a camera, millimeter wave radar, and LIDAR (Light Detection and Ranging) that can detect objects around the vehicle 100. The sensor group 101 may also include a sensor for measuring the yaw rate (yaw angle) of the vehicle 100. The sensor group 101 outputs the detection results to the control device 108.

[0012] The turn signal lever 102 is an operator for receiving an operation to change 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 indicating the right side of the vehicle 100, a state indicating the left side of the vehicle 100, and a state indicating neither side. The control device 108 switches the indication state of the turn signal 107 in response to the operation of the turn signal lever 102 by the driver. The turn signal 107 may be located on both the right and left sides of the vehicle 100. For example, when the driver operates the turn signal lever 102 to indicate the right side, the control device 108 causes the turn signal 107 on the right side of the vehicle 100 to flash. When the driver operates the turn signal lever 102 to indicate the left side, the control device 108 causes the turn signal 107 on the left side of the vehicle 100 to flash. The control device 108 turns off the turn signals 107 on both sides of the vehicle 100 when the driver operates the turn signal lever 102 so as not to indicate either direction. The control device 108 may change the indication state of the turn signals 107 without depending on the driver's operation of the turn signal lever 102. For example, the control device 108 may turn off the blinking turn signals 107 in response to the completion of 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 can be used to acquire information about the current position and / or driving path (driving history) of the vehicle 100. The vehicle-to-vehicle communication antenna 104 is an antenna that transmits and receives various data to and from surrounding vehicles. For example, the vehicle-to-vehicle communication antenna 104 can be used to acquire information about the current position, speed, and driving path of surrounding vehicles.

[0014] The notification device 105 is a device that notifies an occupant (e.g., a driver) of the vehicle 100. When there is a possibility that the vehicle 100 will collide with a nearby vehicle, the control device 108 can notify the occupant of the vehicle 100 of the possibility of a collision with the nearby vehicle by using the notification device 105 as driving assistance. 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 that displays visual information for the occupant. For example, the MID 105a may display information indicating a possibility of a collision with another vehicle. The HUD 105b is a display device that displays visual information for the occupant. For example, the HUD 105b may display information indicating a possibility of a collision with another vehicle. The MID 105a and the HUD 105b may be provided at different positions on the vehicle 100. For example, the MID 105a may be provided on an instrument panel of the vehicle 100, and the HUD 105b may be provided on a windshield of the vehicle 100. The speaker 105c is an acoustic device for outputting audio information to the occupants. For example, the speaker 105c may output a voice or a notification sound indicating the possibility of a collision with another vehicle.

[0015] The braking device 106 is a device, such as a brake, for performing a braking operation on the vehicle 100. When there is a possibility that the vehicle 100 will collide with a nearby vehicle, the control device 108 operates the braking device 106 to assist in decelerating the vehicle 100 as driving assistance, thereby making it possible to avoid a collision with the nearby vehicle.

[0016] The control device 108 is a device (computer) that controls the vehicle 100, and can be configured, for example, by an ECU (Electric Control Unit). The control device 108 can perform driving assistance through inter-vehicle communication with other vehicles and processing within the vehicle 100. For example, the control device 108 can perform driving assistance without using map information. The control device 108 includes a processing unit 110, a storage unit 111, a GNSS module 113, and an inter-vehicle communication module 114, which 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 assistance program) for the processing unit 110 to execute driving assistance processing for the vehicle 100, a program (learning program) for the processing unit 110 to learn risk locations, various data, etc. The storage unit 111 may store risk location information 112 created based on intersections between the driving trajectory of the vehicle 100 and the driving trajectory of another vehicle. The risk location information 112 may include multiple risk locations. A risk location may be a location where there is a possibility or a high probability that the vehicle 100 will collide with another vehicle. The risk location information 112 may be managed as a database.

[0018] The GNSS module 113 receives position information and the like of the vehicle 100 from GNSS satellites via the GNSS antenna 103. The inter-vehicle communication module 114 receives various types of information from other vehicles via the inter-vehicle communication antenna 104.

[0019] The processing unit 110 may include an acquisition unit 110a, a prediction unit 110b, a support unit 110c, and an update unit 110d in order to perform 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 the units 110a to 110d. Other units may be added or some units may be omitted depending on the type of driving support to be performed by the vehicle 100.

[0020] The acquisition unit 110a acquires surrounding vehicle information indicating the current position, vehicle speed, traveling path, and blinker indication state of the surrounding vehicle from surrounding vehicles present around the vehicle 100 via the inter-vehicle communication antenna 104 (inter-vehicle communication module 114). The surrounding vehicle information may explicitly or implicitly indicate the current position, vehicle speed, traveling path, blinker indication state, and yaw rate of the surrounding vehicle. For example, the surrounding vehicle information may include the vehicle speed as is, or may include information for calculating the vehicle speed (current and immediately preceding two geographical positions and their positioning times). Furthermore, the surrounding vehicle information may include the yaw rate as is, or may include information for calculating the yaw rate (current and immediately preceding traveling directions of the surrounding vehicle). The acquisition unit 110a may acquire host vehicle information indicating the current position, speed, traveling path, blinker indication state, 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 indication state of the blinker 107 from the blinker 107, or may store the most recent change command to the blinker 107 and acquire the indication state based on the stored change command.

[0021] The prediction unit 110b predicts the possibility of the vehicle 100 colliding with another vehicle based on the host vehicle information and surrounding vehicle information acquired by the acquisition unit 110a. The prediction unit 110b may set a judgment area and predict the possibility of the vehicle 100 colliding with another vehicle in the judgment area. The prediction unit 110b may also provide driving assistance for the vehicle 100 based on the risk position information 112. For example, when at least one risk position among multiple risk positions included in the risk position information 112 is located near the host vehicle, the prediction unit 110b may set the judgment area to include the risk position.

[0022] The support unit 110c performs driving support (collision prevention support) for the host vehicle 100 based on the prediction result by the prediction unit 110b. In some embodiments, the support unit 110c may perform at least one of the following as driving support for the vehicle 100: notifying the occupants of the vehicle 100 using the notification device 105, and supporting deceleration of the vehicle 100 using the braking device 106. The deceleration support may include support for decelerating the host vehicle 100 until it stops, i.e., stopping support. The stopping support may include not only deceleration of the host vehicle 100, but also determination of a stopping position for the host vehicle 100, route planning toward the stopping position, and automatic steering along the route.

[0023] The update unit 110d identifies an intersection between the travel trajectory of the vehicle 100 and the travel trajectories of the surrounding vehicles. An intersection between the travel trajectory of the vehicle 100 and the travel trajectories of the surrounding vehicles is hereinafter referred to as a trajectory intersection. There is a possibility that a road intersection exists near the trajectory intersection. Furthermore, the update unit 110d updates the risk location information 112 stored in the memory unit 111 based on the identified trajectory intersection. 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 risk location included in the risk location information 112 based on the trajectory intersection.

[0024] 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 other formats. 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.

[0025] The risk location information 112 may include, for each risk location, information regarding a risk location ID, registration date and time, coordinates, and passing direction. 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 was 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 elevation 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 (approach 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 as 0° north, 90° east, 180° south, and 270° west.

[0026] The intersection angle is the intersection angle between the driving trajectory of the host vehicle 100 and the driving trajectory of the other 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 indicates the direction from which the other vehicle intersected with the driving trajectory of the host vehicle. The other vehicle trajectory is the driving trajectory of the other vehicle that passes through the trajectory intersection used to determine the risk position.

[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 will be described in which the vehicle 100 is located in an area where driving on the right is mandatory. In this case, of the left and right sides, the side of the road on which driving on the road is mandatory in the area where the vehicle 100 is located is the right side, and the opposite side is the left side. In addition, the oncoming lane side of the vehicle 100 is the left side of the vehicle 100. The embodiments described in this specification are also applicable to cases in which the vehicle 100 is located in an area where driving on the left is mandatory. In this case, the left and right sides in the processing described below (e.g., right and left turns of the vehicle 100 or other vehicles, and right and left sides of the turn signal indication) are reversed. Specifically, of the left and right sides, the side of the road on which driving on the road is mandatory in the area where the vehicle 100 is located is the left side, and the opposite side is the right side. Furthermore, the oncoming traffic lane of the vehicle 100 is on the right side of the vehicle 100.

[0028] In the example shown in FIG. 3(a), the position where the travel trajectory 301a of the host vehicle 100 traveling straight north and the travel trajectory 302a of the other vehicle OVa traveling straight west intersect is the trajectory intersection CPa. Note that the timing (time) at which the host vehicle 100 passes the trajectory intersection CPa is different from the timing (time) at which the other vehicle OVa passes the trajectory intersection CPa, so no collision occurs between the host vehicle 100 and the other vehicle OVa. Furthermore, the travel 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 travel 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 nearby vehicle present around the host vehicle 100 at the time of acquisition, the other vehicle information may be understood as nearby vehicle information.

[0029] 3(b), the position where a travel trajectory 301b of the host vehicle 100, which travels straight north and turns left, intersects with a travel trajectory 302b of another vehicle OVb, which travels straight south, is the trajectory intersection CPb. Note that the timing (time) at which the host vehicle 100 passes through the trajectory intersection CPb is different from the timing (time) at which the other vehicle OVb passes through the trajectory intersection CPb, and therefore no collision occurs between the host vehicle 100 and the other vehicle OVb. Furthermore, the travel trajectory 301b of the host vehicle 100, like the travel trajectory 301a, 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 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 104 (inter-vehicle communication module 114).

[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 a driving assistance program and / or a learning program as described above, or may be realized by an integrated circuit such as a programmable logic device (PLD) or an application specific integrated circuit (ASIC). In the example of FIG. 1, the control device 108 is shown as a single element, but may be divided into two or more elements as necessary.

[0031] <Management of surrounding vehicles> An example of a process for managing nearby vehicles will be described with reference to Fig. 4. The process shown in the flowchart of Fig. 4 is executed by the processing unit 110 in accordance with a learning program read from the storage unit 111. The process of Fig. 4 may be started, for example, when the ignition of the vehicle 100 is turned on. The process of Fig. 4 may be repeatedly executed until the ignition of the vehicle 100 is turned off.

[0032] In step S401, the processing unit 110 (for example, 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 S402, and otherwise transitions the process to step S404. 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 104 (vehicle-to-vehicle communication module 114).

[0033] In step S402, the processing unit 110 (for example, the acquisition unit 110a) registers the other vehicle discovered in step S401 as a nearby vehicle. For example, the memory 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 will be described later, the nearby vehicle is subject to collision possibility determination. Instead of managing the information about the nearby 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, the acquisition unit 110a) starts acquiring surrounding vehicle information from surrounding vehicles through vehicle-to-vehicle communication. As described above, the surrounding vehicle information may represent the vehicle speed, position, and travel trajectory of the surrounding vehicles. After starting to acquire surrounding vehicle information in step S402, the processing unit 110 repeatedly acquires surrounding vehicle information periodically (for example, every 100 ms) until vehicle-to-vehicle communication with the surrounding vehicles becomes impossible.

[0035] After starting to acquire the surrounding vehicle information, in step S403, the processing unit 110 (for example, the acquisition unit 110a) determines whether there is one or more registered surrounding vehicles that are no longer able to perform inter-vehicle communication. If such a vehicle is present, the processing unit 110 transitions the process to step S405, and otherwise transitions the process to step S401. For example, if a surrounding vehicle moves out of the communication range of inter-vehicle communication or if the power of the surrounding vehicle is turned off, the vehicle 100 will no longer be able to perform inter-vehicle communication with the surrounding vehicle.

[0036] In step S405, the processing unit 110 (for example, 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.

[0037] As described above, by executing the process of FIG. 4, the processing unit 110 can periodically acquire the latest nearby vehicle information from other vehicles in the vicinity of the vehicle 100 (that is, nearby vehicles).

[0038] <Driving assistance processing> The driving assistance process of some embodiments will be described with reference to Figures 6 to 18. As described with reference to Figure 3(a), when another vehicle is included in the range to the side of the host vehicle 100, if the host vehicle 100 and the other vehicle both travel straight, there is a possibility that these vehicles will collide. On the other hand, as described with reference to Figure 3(b), when the other vehicle is included in the range ahead of the host vehicle 100, there is a possibility that these vehicles will collide if the host vehicle 100 turns left and the other vehicle travels straight. In this way, the situation in which these vehicles may collide may vary depending on the position of the other vehicle relative to the host vehicle 100. Therefore, in some embodiments, the control device 108 performs different driving assistance depending on whether the surrounding vehicle is present in the range ahead of the host vehicle 100 or in the range to the side of the host vehicle 100.

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

[0040] In step S501, the processing unit 110 (for example, the support unit 110c) determines whether or not a risk position exists within a predetermined distance (for example, 100 m) in the traveling direction of the vehicle 100 by referring to the risk position information 112 stored in the memory unit 111. For example, the processing unit 110 can determine whether or not a risk position exists 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] The processing unit 110 transitions the process to step S502 if a risk position exists within a predetermined distance (e.g., 100 m) in the traveling direction of the host vehicle 100, and transitions the process to step S503 if a risk position does not exist within the predetermined distance. In step S502, the processing unit 110 determines whether to provide driving assistance using a risk position included within the predetermined distance. Details of this process will be described later. In step S503, the processing unit 110 determines whether to provide driving assistance without using a risk position. Details of this process will be described later.

[0042] With reference to FIG. 6, a range for selecting a driving assistance method when a risk location is not included within a predetermined distance in the traveling direction of the vehicle 100 will be described. The range 600 is located ahead of the vehicle 100. The range ahead of the vehicle 100 may refer to a range that includes the front of the vehicle 100. The range 600 may be a sector-shaped range as shown in FIG. 6, or may have another shape. The sector-shaped range may be defined by a predetermined distance and a predetermined angle. The predetermined distance may be, for example, between 800 m and 1000 m, for example, 900 m. The same applies to the predetermined distance of the sector-shaped range below. The range 600 may be symmetrical with respect to the direction ahead of the vehicle 100. The central angle of the range 600 may be, for example, approximately 100 to 110 degrees.

[0043] Area 601 is located on the side of vehicle 100. The side of vehicle 100 may refer to an area including a diagonally forward direction of vehicle 100. Area 601 may include a direction directly to the side of vehicle 100. Area 601 may be a sector-shaped area as shown in FIG. 6, or may have another shape. The sector-shaped area may be defined by a predetermined distance and a predetermined angle. In the example of FIG. 6, areas 601 are located on both the right and left sides of vehicle 100. The central angle of area 601 may be, for example, approximately 80 to 90 degrees.

[0044] In the example of FIG. 6, a portion of range 600 and a portion of range 601 overlap. The central angle of this overlapping portion may be, for example, approximately 10 to 20 degrees. When a nearby vehicle is present in this overlapping portion, this nearby vehicle becomes a target of driving assistance in both the situation of FIG. 3(a) and the situation of FIG. 3(b). Instead of the example of FIG. 6, range 600 and range 601 may simply touch each other or may be separated from each other. Range 600, range 601 on the right side of vehicle 100, and range 601 on the left side of vehicle 100 may all be the same size, or may have at least partially different sizes.

[0045] When the surrounding vehicle is included in the range 601, the control device 108 may collide with another vehicle by moving straight ahead as shown in FIG. 3(a). Therefore, the control device 108 predicts the possibility of a collision when the host vehicle 100 moves straight ahead. This operation will be described later with reference to FIGS. 7 to 12. On the other hand, when the surrounding vehicle is included in the range 600, the control device 108 may collide with another vehicle by turning left as shown in FIG. 3(b). Therefore, the control device 108 predicts the possibility of a collision when the host vehicle 100 moves straight ahead. This operation will be described later with reference to FIGS. 13 to 16. The positions of the ranges 600 and 601 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.

[0046] FIG. 7 illustrates an example of processing for executing driving assistance when a nearby vehicle RV (FIG. 10(a)) is present within a range 601 to the side of the host vehicle 100 in step S503 (i.e., processing when a risk position is not included within a predetermined distance in the traveling direction of the host vehicle 100). The processing shown in the flowchart in FIG. 7 is executed by the processing unit 110 in accordance with a driving assistance program read from the storage unit 111. The processing in FIG. 7 may be executed for a nearby vehicle RV, for example, each time a nearby vehicle RV is newly registered in step S702 in FIG. 7 while the driving assistance setting is on. In the processing in FIG. 7, multiple other vehicles may be registered as nearby vehicles. The processing in FIG. 7 is executed for each of these multiple nearby vehicles.

[0047] In step S701, the processing unit 110 (for example, its prediction unit 110b) determines whether the surrounding vehicle RV is present within the range 601 to the side of the host vehicle 100. If it is determined that the surrounding vehicle RV is present within the range 601 to the side of the host vehicle 100, the processing unit 110 transitions the process to step S702, and otherwise repeats step S701. 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 is present within the range 601.

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

[0049] A specific example of the processing of step S702 will be described with reference to Fig. 8. In step S801, the processing unit 110 determines a 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 greater than a threshold accuracy. If the processing unit 110 determines that the prediction accuracy of the predicted trajectory of the host vehicle 100 is equal to or greater than the threshold accuracy, the processing unit 110 transitions the processing to step S802, and if the processing unit 110 determines that the prediction accuracy of the predicted trajectory of the host vehicle 100 is less than the threshold accuracy, the processing unit transitions the processing to step S805.

[0050] The processing unit 110 may determine a predicted trajectory of the host vehicle 100 based on the host vehicle information. For example, the processing unit 110 may calculate a curvature radius at the current time based on a yaw rate included in the host vehicle information, and determine an arc having this curvature radius 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 time-differentiating the yaw rate. For example, the processing unit 110 may determine the reliability of the prediction of the predicted trajectory by referring to a correspondence table 900 shown in FIG. 9. The correspondence table 900 indicates the correspondence relationship between the yaw angular acceleration and the reliability. The correspondence table 900 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. 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, the processing unit 110 may determine the reliability of the prediction of the predicted trajectory by referring to a correspondence table 900 shown in FIG. 9. 2 more than 2° / s 2 If it is less than 70%, the confidence level of the predicted trajectory prediction is determined to be 70%.

[0052] Generally, the accuracy of measuring the radius of curvature of the host vehicle 100 is low at low vehicle speeds. Therefore, the processing unit 110 may determine that the prediction accuracy of the predicted trajectory is higher as the vehicle speed of the host vehicle 100 is higher. For example, the processing unit 110 may classify the reliability of the prediction of the predicted trajectory into two stages. 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 (e.g., 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, the processing unit 110 may determine that the prediction accuracy of the predicted trajectory of the vehicle 100 is equal to or greater than the threshold accuracy when the reliability determined based on the yaw angular acceleration is equal to or greater than a threshold reliability (e.g., 70%) and the vehicle speed is equal to or greater than a threshold vehicle speed (e.g., 20 km / h), and may otherwise determine that the prediction accuracy of the predicted trajectory of the 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 equal to or greater than a threshold radius (e.g., 3000 m). If the processing unit 110 determines that the radius of curvature of the host vehicle 100 is equal to or greater than the threshold radius, the processing unit 110 transitions the processing to step S803, and if the processing unit 110 determines that the radius of curvature of the host vehicle 100 is less than the threshold radius, the processing unit 110 transitions the processing to step S804.

[0055] In step S803, the processing unit 110 determines the intersection of the straight trajectory of the host vehicle 100 and the straight trajectory of the peripheral vehicle RV as the predicted intersection. The straight trajectory is the trajectory when it is assumed that the host vehicle 100 is traveling straight. The processing of step S803 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 (e.g., 3000 m). In this case, it is considered that the occupant of the host vehicle 100 intends to travel the host vehicle 100 straight. Therefore, the processing unit 110 determines the predicted intersection using the straight trajectory of the host vehicle 100. An example of the predicted intersection in step S803 will be described with reference to FIG. 10(a). In this example, the intersection of the straight trajectory 1000 of the host vehicle 100 and the straight trajectory 1001 of the peripheral vehicle RV is determined as the predicted intersection 1002.

[0056] In step S804, the processing unit 110 determines the intersection between the predicted trajectory of the host vehicle 100 and the straight trajectory of the surrounding vehicle RV as the predicted intersection. 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 (e.g., 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 predicted intersection using the predicted trajectory of the host vehicle 100. An example of the predicted intersection in step S804 will be described with reference to FIG. 10(b). In this example, the intersection between the predicted trajectory 1010 of the host vehicle 100 and the straight trajectory 1011 of the surrounding vehicle RV is determined as the predicted intersection 1012. The predicted trajectory 1010 may be a circular arc having the determined radius of curvature.

[0057] In step S805, the processing unit 110 determines a 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 greater than a threshold accuracy. If the processing unit 110 determines that the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is equal to or greater than the threshold accuracy, the processing unit 110 transitions the processing to step S806, and if the processing unit 110 determines 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 processing to step S809.

[0058] The processing unit 110 may determine a predicted trajectory of the nearby vehicle RV based on the nearby vehicle information. For example, the processing unit 110 may calculate a curvature radius at the current time based on a yaw rate included in the nearby vehicle information, and determine an arc having this curvature radius 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. The method of determining the prediction accuracy of the predicted trajectory of the surrounding vehicle RV may be the same as the method of determining the prediction accuracy of the predicted trajectory of the host vehicle 100 described above, and therefore, a duplicated explanation will be 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. If the processing unit 110 determines that the radius of curvature of the surrounding vehicle RV is equal to or greater than a threshold radius (e.g., 3000 m), the processing unit 110 transitions the processing to step S807, and if the processing unit 110 determines that the radius of curvature of the surrounding vehicle RV is less than the threshold radius, the processing unit 110 transitions the processing to step S808.

[0061] In step S807, the processing unit 110 determines the intersection of the straight trajectory of the host vehicle 100 and the straight trajectory of the surrounding vehicle RV as the predicted intersection. 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, and therefore, a redundant description will be omitted.

[0062] In step S808, the processing unit 110 determines the intersection between the straight trajectory of the host vehicle 100 and the predicted trajectory of the surrounding vehicle RV as the predicted intersection. The processing unit 110 may use the predicted trajectory determined in step S805. The processing of step S808 is executed when it is determined that the radius of curvature of the surrounding vehicle RV is less than a threshold radius (e.g., 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 using the predicted trajectory of the surrounding vehicle RV. An example of the predicted intersection in step S808 will be described with reference to FIG. 10(c). In this example, the intersection between the straight trajectory 1020 of the host vehicle 100 and the predicted trajectory 1021 of the surrounding vehicle RV is determined as the predicted intersection 1022. The predicted trajectory 1021 may be a circular arc having the determined radius of curvature.

[0063] After determining the predicted intersection in step S803, step S804, step S807, or step S808, the processing unit 110 determines an evaluation distance in step S809 based on the predicted intersection and the current position of the host vehicle 100. The evaluation distance may be a distance for evaluating the proximity status between the host vehicle 100 and the peripheral vehicle RV. As described above, according to the method of FIG. 8, the processing unit 110 determines an evaluation distance for evaluating the proximity status between the host vehicle 100 and the peripheral vehicle RV based on the predicted trajectory of the host vehicle 100 and the predicted trajectory of the peripheral vehicle RV. Furthermore, 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 peripheral vehicle RV, and the radius of curvature of the predicted trajectory of the peripheral vehicle RV.

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

[0065] 10(b), when the predicted intersection 1012 is not on the straight trajectory of the host vehicle 100, the processing unit 110 may determine, as the evaluation distance, a distance 1013 between the host vehicle 100 and the predicted intersection 1012. Alternatively, the processing unit 110 may determine, as the evaluation distance, the straight-line distance between the predicted intersection 1012 and a plane that passes through a part (for example, the center) of the host vehicle 100 and has the traveling direction as its normal line. Alternatively, the processing unit 110 may determine, as the evaluation distance, the distance on the predicted trajectory 1010 between the host vehicle 100 and the predicted intersection 1012.

[0066] In step S810, the processing unit 110 determines whether the evaluation distance determined in step S809 is within a predetermined range (for example, 100 m). If the processing unit 110 determines that the evaluation distance is within the predetermined range (for example, 100 m), the processing unit 110 transitions the processing to step S811, and if the processing unit 110 determines that the evaluation distance is not within the predetermined range, the processing unit 110 transitions the processing to step S812.

[0067] In step S811, the processing unit 110 determines that there is no possibility of a collision. When step S811 is executed, the processing unit 110 transitions the processing to step S707 in FIG. 7 after the processing in FIG. 8 ends. In step S812, the processing unit 110 determines that there is a possibility of a collision. When step S812 is executed, the processing unit 110 transitions the processing to step S703 in FIG. 7 after the processing in FIG. 8 ends. The determination result that there is a possibility of a collision may be changed in subsequent processing (for example, step S704 in 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 that the prediction accuracy of the predicted trajectory of the peripheral vehicle RV is less than the threshold accuracy, in step S811, the processing unit 110 may predict that there is no possibility of a collision between the host vehicle 100 and the peripheral vehicle RV. When the prediction accuracy of the predicted trajectories of the host vehicle 100 and the peripheral vehicle RV is low, there is a possibility that driving assistance (for example, a notification to the occupants) will be performed even though the two vehicles are not approaching each other. Therefore, in such a case, by predicting that there is no possibility of a collision and suppressing driving assistance (for example, a notification to the occupants), it is possible to prevent the occupants from feeling annoyed.

[0069] 10, the processing unit 110 determines the predicted intersection by using the straight-line trajectory of the surrounding vehicle RV in steps S803 and S804. Alternatively, the processing unit 110 may determine the predicted intersection by using the predicted trajectory of the surrounding vehicle RV when it is determined in steps S803 and S804 that the prediction accuracy of the predicted trajectory of the surrounding vehicle RV is equal to or greater than a threshold accuracy and that the radius of curvature of the surrounding vehicle RV is less than a threshold radius.

[0070] Returning to the description of FIG. 7, in step S703, the processing unit 110 (for example, the prediction unit 110b thereof) sets a judgment area using the predicted intersection determined by the method of FIG. 8 as a reference position, and stores the judgment area in the storage unit 111. The judgment area may be an area in which a collision possibility is predicted. With reference to FIG. 11(a), an example of the judgment area 1103 that is set using 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 trajectory 1100 of the host vehicle 100 and the straight trajectory 1101 of the surrounding vehicle RV is determined as the predicted intersection 1102. Alternatively, the description of FIG. 11 can also be applied to the case of FIG. 10(b) or FIG. 10(c).

[0071] The determination area 1103 may be a rectangle that includes the predicted intersection 1102 and has sides parallel to the straight trajectory 1100 of the host vehicle 100. Alternatively, the determination area 1103 may have another shape. The position and shape of the determination area 1103 relative to the predicted intersection 1102 may be set in advance (for example, when the vehicle 100 is manufactured or when the software is updated) and stored in the memory unit 111. When a risk position exists near the determination area 1103, the processing unit 110 may expand the determination area 1103 to include the risk position.

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

[0073] Whether the peripheral 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 farther from the host vehicle 100 and the predicted intersection 1102 may be the same (for example, approximately 1.5 m, equivalent to a half lane). As a result, a length 1106 of a portion of the determination area 1103 that is closer to the host vehicle 100 than the predicted intersection 1102 when the peripheral vehicle RV is on the right side of the host vehicle 100 is greater than a length 1106 of a portion of the determination area 1103 that is closer to the host vehicle 100 than the predicted intersection 1102 when the peripheral vehicle RV is on the left side of the host vehicle 100. When the peripheral vehicle RV is on the right side of the host vehicle 100, there is a possibility that an oncoming lane of the lane in which the peripheral 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 prevent 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. If 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 transitions the processing to step S705, and otherwise transitions the processing to step S707.

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

[0076] The processing unit 110 may predict that there is a possibility of a collision if the arrival time is equal to or less than a threshold time, and may determine that there is no possibility of a collision if the arrival time is greater than the threshold time. The threshold time may be set by an 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 stopping time of the surrounding vehicle RV. The stopping time of the surrounding vehicle RV is the time it takes for the surrounding vehicle RV to stop at a deceleration (e.g., 0.4 G) due to a typical braking operation. FIG. 12 shows a specified range (upper speed limit, lower speed limit) for the speed of the surrounding vehicle RV, and an upper time limit and a lower time limit for the time to collision (TTC). The specified range is the speed range of the surrounding vehicle RV within which driving assistance for the host vehicle 100 is performed. The upper time limit is the upper limit of the time to collision set arbitrarily by the driver or the like, and the lower time limit is the lower limit of the time to collision set based on the measurement position accuracy of the GNSS.

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

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

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

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

[0082] In step S705, the processing unit 110 (e.g., its assistance unit 110c) determines whether an assistance condition is satisfied. If it is determined that the assistance condition is satisfied, the processing unit 110 transitions the process to step S706; otherwise, the processing unit 110 transitions the process to step S707. The assistance condition may be a condition that must be satisfied in order to perform driving assistance. For example, the assistance condition may be based on whether the speed of the surrounding vehicle RV is within a specified range. The specified range may be set in advance by a lower speed limit value and an upper speed limit value for the speed of the surrounding vehicle RV. If the speed of the surrounding vehicle RV is equal to or lower than the lower speed 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. In other words, the lower speed limit value of the specified range for 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 host vehicle 100. Furthermore, if the speed of the surrounding vehicle RV is equal to or greater than the upper limit of the specified range, the surrounding vehicle RV is likely not a vehicle traveling on the road into which the host vehicle 100 is entering, such as traveling on an expressway near the road into which the host vehicle 100 is entering. In other words, the upper limit of the specified range for the speed of the surrounding vehicle RV can be set to a value that makes it possible to determine whether the surrounding vehicle RV is a vehicle traveling on the road into which the host vehicle 100 is entering, or a vehicle traveling on an expressway near the road. In this way, by performing / suppressing driving assistance depending on whether the speed of the surrounding vehicle RV is within the specified range, it is possible to reduce the annoyance felt by the driver of the host vehicle 100 due to the driving assistance.

[0083] In step S706, the processing unit 110 (for example, the 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 occupants of the host vehicle 100 of the possibility of a collision using the alarm device 105, and can perform a braking operation for the host vehicle 100 using the braking device 106.

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

[0085] Step S707 is executed when it is determined in step S704 that there is no possibility of collision or when it is determined in step S705 that the assistance condition is not satisfied. 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 of FIG. 7 has been deregistered in step S405 of FIG. 4. If it is determined that the registration of the surrounding vehicle RV has been deregistered, the processing unit 110 transitions the processing to step S708, and otherwise transitions the processing to step S702. If the registration of the surrounding vehicle RV has been deregistered, it is considered that the surrounding vehicle RV is no longer present in the vicinity of the host vehicle 100. Therefore, the processing unit 110 ends the processing without performing driving assistance regarding a collision with this surrounding vehicle RV. In this case as well, in step S708, the processing unit 110 (for example, its prediction unit 110b) deletes the unnecessary determination area from the storage unit 111.

[0086] If it is determined in step S707 that the registration of the surrounding vehicle RV has not been cancelled, the process returns to step S702. In this case, if the predicted path of the host vehicle 100 and the predicted path of the surrounding vehicle RV still intersect, a determination area is set in step S703 using the predicted intersection 1102 as a reference position. If a vehicle (host vehicle 100 or surrounding vehicle RV) changes its position within a lane or changes lanes, the position of the predicted intersection 1102 may change. Because 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) resets 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 performed based on the updated determination area. If the predicted intersection point 1102 cannot be determined in step S703, the most recently determined reference position and decision 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 change amount, the processing unit 110 may increase the time threshold used for comparison with the 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 is changing. Therefore, by increasing the time threshold, it becomes easier to predict the possibility of a collision, thereby improving safety.

[0088] According to the method of Fig. 7, when multiple peripheral vehicles are present within range 601 to the side of host vehicle 100, an individual reference position is used for each of the multiple peripheral vehicles. Specifically, the method of Fig. 7 is executed individually for each of the multiple peripheral vehicles. As a result, a predicted intersection between the predicted path of host vehicle 100 and the predicted path of each peripheral vehicle is also determined for each of the multiple peripheral vehicles. As a result, an individual judgment area is set for each of the multiple peripheral vehicles based on the individual reference position. This makes it possible to appropriately predict the possibility of a collision with each of the multiple peripheral vehicles.

[0089] FIG. 13 illustrates an example of processing for executing driving assistance when a nearby vehicle RV (FIG. 16) is present within a range 600 ahead of the host vehicle 100 in step S503 (i.e., processing when a risk position is not included within a predetermined distance in the traveling direction of the host vehicle 100). The processing shown in the flowchart in FIG. 13 is executed by the processing unit 110 in accordance with a learning program read from the memory unit 111. The processing in FIG. 13 may be started, for example, when the driving assistance setting is turned on. The processing in FIG. 13 may 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 (e.g., 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 processing proceeds to step S1302. Otherwise, the processing unit 110 proceeds 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 limit of the threshold used in step S1301 is a value below which the vehicle speed falls after the vehicle 100 decelerates to turn (e.g., turn left or turn right), and may be, for example, 20 km / h. The lower limit of the threshold used in step S1301 is a value below which the vehicle speed falls when the vehicle 100 is stopped or nearly stopped, and may be, for example, 2 km / h. The position at which the host vehicle 100 is determined to be within the threshold range is referred to as a turning preparation position 1601 (FIG. 16). It should be noted that the vehicle 100 may be within the threshold range even if it does not turn. Even in this case, the processing unit 110 detects the turning preparation position 1601 and executes the processes from step S1302 onwards.

[0091] In step S1302, the processing unit 110 (for example, the prediction unit 110b) sets a determination area using the turning preparation position 1601 as a reference position, and stores the reference position and the determination area in the storage unit 111. The determination area may be an area in which a collision possibility is predicted. With reference to FIG. 16 , an example of the determination area 1602 set using the turning preparation position 1601 as a reference position will be described. The determination area 1602 may be a rectangle centered on the left front position 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 a 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 a 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 another shape. The position of the determination area 1602 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. When a risk position exists near the determination area 1602, the processing unit 110 may expand the determination area 1602 to include the risk position. The processing unit 110 sets the determination area 1602 to include the turning preparation position 1601 (i.e., the reference position) and to be offset toward the oncoming lane (to the left in the example of FIG. 16 ) with respect to the host vehicle 100 in a direction perpendicular to the predicted path of the host vehicle 100. This makes it possible to appropriately predict the possibility of a collision that may occur when the host vehicle 100 turns left.

[0092] The processing from step S1303 onward is performed using the reference position and judgment area set in step S1302. As described above, since the method of FIG. 13 is repeatedly performed, steps S1301 and S1302 are also repeatedly performed. Therefore, while the vehicle speed of the host vehicle 100 is within a threshold range (e.g., 2 km / h or more and less than 20 km / h), the reference position and judgment area continue to be updated, and the processing from step S1303 onward is performed using the latest reference position and judgment area. When the vehicle speed of the host vehicle 100 falls outside the threshold range (e.g., less than 2 km / h or 20 km / h or more), the updating of the reference position and judgment area is stopped, and the processing from step S1303 onward is performed using the reference position and judgment area at the time the updating was stopped. If the reference position and judgment area have not been set at the time step S1303 is performed, the processing unit 110 may omit steps S1303 to S1310 and return to the processing of S1301.

[0093] In step S1303, the processing unit 110 (e.g., its prediction unit 110b) determines a predicted turning trajectory 1604 of the host vehicle 100. The predicted turning trajectory 1604 may be a turning trajectory predicted when the host vehicle 100 turns (e.g., turns left) into an oncoming lane. The predicted turning trajectory 1604 may be set in advance (e.g., when the vehicle 100 is manufactured or when the software is updated) and stored in the storage unit 111. The predicted turning trajectory 1604 set in advance in this manner may be referred to as a default predicted turning trajectory 1604.

[0094] A plurality of candidates for the predicted turning trajectory 1604 may be stored in the memory unit 111. The processing unit 110 (e.g., 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 the selected predicted turning trajectory for subsequent processing. For example, when the steering angle of the host vehicle 100 is small, the processing unit 110 may select the predicted turning trajectory 1604 with a small radius of curvature because it is considered that the host vehicle 100 is about to turn left 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 the predicted turning trajectory 1604 with a large radius of curvature because it is considered that the host vehicle 100 is about to turn left at a large intersection.

[0095] In step S1304, the processing unit 110 (for example, its prediction unit 110b) identifies a peripheral vehicle RV present within the range 600 ahead of the host vehicle 100 as a target vehicle for subsequent processing. If no peripheral vehicle RV exists within the range 600, no target vehicle is identified. If multiple peripheral vehicles RV exist within the range 600, all of these multiple peripheral vehicles RV are identified as target vehicles. This identification may be performed based on the current positions of the peripheral vehicles RV included in the latest peripheral vehicle information acquired from the peripheral vehicles RV. In the example shown in FIG. 16, one peripheral vehicle RV exists within the range 600.

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

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

[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 approaching state between the host vehicle 100 and the surrounding vehicle RV.

[0099] A specific example of a method for determining the likelihood of collision based on the evaluation distance will be described with reference to Fig. 14. Steps S1401 and S1402 may be the same as steps S801 and S802 in Fig. 8, and therefore redundant description will be omitted.

[0100] In step S1403, the processing unit 110 determines the distance between the straight trajectory of the host vehicle 100 and the surrounding vehicle RV as the evaluation distance. The straight trajectory is a trajectory when the host vehicle 100 is assumed to be traveling straight. The processing 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 (e.g., 3000 m). In this case, it is considered that the occupant of the host vehicle 100 intends to drive the host vehicle 100 straight. Therefore, the processing unit 110 determines the evaluation distance using the straight trajectory of the host vehicle 100. An example of the evaluation distance in step S1403 will be described with reference to FIG. 15(a). In this example, a distance 1501 between the straight 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 refer to the shortest distance between the trajectory and the center of the vehicle. Alternatively, another part of the vehicle may be used to determine 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 processing of step S1404 is executed when it is determined that the radius of curvature of the host vehicle 100 is less than a threshold radius (e.g., 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. An example of the evaluation distance in step S1404 will be described with reference to FIG. 15(b). In this example, a 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, and therefore redundant explanations will be omitted. In step S1407, the processing unit 110 determines the distance between the straight path 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, and therefore redundant explanations will be 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 processing of step S1408 is executed when it is determined that the radius of curvature of the surrounding vehicle RV is less than a threshold radius (e.g., 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. An example of the evaluation distance in step S1408 will be described with reference to FIG. 15(c). In this example, a 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 within a predetermined range (for example, 3 to 4 m, which is the length of one lane). If the processing unit 110 determines that the evaluation distance is not within the predetermined range, it transitions the process to step S1410, and if the processing unit 110 determines that the evaluation distance is within the predetermined range, it transitions the process to step S1411.

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

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

[0107] 14, the processing unit 110 determines an evaluation distance for evaluating the approach status between the host vehicle 100 and the peripheral vehicle RV, based on the predicted trajectory of the host vehicle 100 and the predicted trajectory of the peripheral vehicle RV. Furthermore, 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 peripheral vehicle RV, and the radius of curvature of the predicted trajectory of the peripheral vehicle RV.

[0108] Returning to the explanation of Fig. 13, in step S1307, the processing unit 110 (for example, the support unit 110c) determines whether the support condition is satisfied. If it is determined that the support condition is satisfied, the processing unit 110 transitions the process to step S1308, and otherwise transitions the process to step S1309. Step S1307 may be the same as step S705, and therefore a duplicated explanation will be omitted.

[0109] In step S1308, the processing unit 110 (for example, the 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 occupants of the host vehicle 100 of a possibility of a collision using the alarm device 105, or perform a braking operation for the host vehicle 100 using the braking device 150.

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

[0111] Step S1309 is executed when it is determined in step S1306 that there is no possibility of a collision, or when it is determined in step S1307 that the assistance condition is not satisfied. In step S1309, the processing unit 110 (e.g., its prediction unit 110b) determines whether the host vehicle 100 has moved a predetermined distance (e.g., 30 m) or more from the reference position stored in step S1302. 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 process to step S1311; otherwise, the processing unit 110 transitions the process to step S1310. If the host vehicle 100 has moved a predetermined distance or more from the reference position, it is considered that there is no possibility that the host vehicle 100 will collide with the nearby vehicle RV at that point. Therefore, the processing unit 110 ends the process without performing driving assistance for this collision with the nearby vehicle RV. In this case as well, in step S1311, the processing unit 110 (for example, the prediction unit 110b) deletes from the storage unit 111 the reference positions and determination regions that are no longer needed.

[0112] Step S1310 is executed when it is determined in step S1310 that the host vehicle 100 is not away from the reference position by a predetermined distance or more. In step S1310, the processing unit 110 (e.g., its prediction unit 110b) may update the predicted turning trajectory 1604 based on a 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 predicted turning trajectory 1604 may be updated when the current steering angle of the host vehicle 100 becomes equal to or larger 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 nearby vehicle RV that is now included in the range 600 as a target vehicle for subsequent processing. In addition, the collision possibility in step S1306 is determined based on the updated predicted turning trajectory 1604.

[0113] 13, when multiple peripheral vehicles are present within the range 600 ahead of the host vehicle 100, a common reference position (i.e., turning preparation position 1601) is used for the multiple peripheral vehicles. As a result, a common determination area is set for each of the multiple peripheral vehicles based on the common reference position. This makes it possible to appropriately estimate the possibility of a collision when the host vehicle 100 turns into the oncoming lane (for example, when turning left).

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

[0115] In the above-described driving assistance method, a nearby vehicle RV is set as a target for collision possibility prediction based on whether the nearby vehicle RV is located within range 600 or 601 in Fig. 6. The processing unit 110 may determine whether or not to set the nearby vehicle RV as a target for collision possibility prediction based on other information. An example of a method for determining a nearby vehicle RV as a target for collision possibility prediction will be described with reference to Fig. 17.

[0116] The processing unit 110 may determine whether to target the nearby vehicle RV for collision possibility prediction, further based on a rotation angle 1703 of a path vector 1702 of the nearby vehicle RV relative to a path vector 1701 of the host vehicle 100. The path vector 1701 may be a unit vector facing the vehicle's traveling direction. For the sake of explanation, the rotation angle 1703 is defined as positive in the clockwise direction and negative in the counterclockwise direction. The processing unit 110 can determine the approach direction of the nearby vehicle RV based on the direction of the nearby vehicle RV relative to the host vehicle 100 and the rotation angle 1703 of the path vector 1702 of the nearby vehicle RV relative to the path vector 1701 of the host vehicle 100.

[0117] Even if the nearby vehicle RV is included in the range 600 ahead of the host vehicle 100, if the nearby 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 nearby vehicle RV. Therefore, the processing unit 110 may treat the nearby vehicle RV as a target for determining the possibility of a collision in the processing of Figures 7 and 13 when the nearby vehicle RV is within the range 600 ahead of the host vehicle 100 and the rotation angle 1703 is within a predetermined range (for example, 160° to 200°).

[0118] Even if the nearby vehicle RV is included in the range 601 on the right side of the host vehicle 100, if the nearby vehicle RV is traveling in the same direction as the host vehicle 100 or in the opposite direction, or if the nearby vehicle RV is 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 nearby vehicle RV. Therefore, the processing unit 110 may treat the nearby vehicle RV as a target for determining the possibility of a collision in the processing of Figures 7 and 13 when the nearby vehicle RV is included in the range 601 on the right side of the host vehicle 100 and the rotation angle 1703 is included in a predetermined range (for example, -110° to -70°).

[0119] Even if the nearby vehicle RV is included in the range 601 on the left side of the host vehicle 100, if the nearby vehicle RV is traveling in the same direction as the host vehicle 100 or in the opposite direction, or if the nearby vehicle RV is 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 nearby vehicle RV. Therefore, the processing unit 110 may treat the nearby vehicle RV as a target for determining the possibility of a collision in the processing of Figures 7 and 13 when the nearby vehicle RV is included in the range 601 on the left side of the host vehicle 100 and the rotation angle 1703 is included in a predetermined range (for example, 70° to 110°).

[0120] Next, a process for determining whether to provide driving assistance using a risk position included within a predetermined distance in step S502 of Fig. 5 will be described. The processing unit 110 may predict the possibility of a collision between the host vehicle 100 and the surrounding vehicle RV based on the traveling trajectory of the other vehicle associated with the risk position in the risk position information 112 and the surrounding vehicle information. The traveling trajectory of the other vehicle included in the risk position information 112 may be a traveling trajectory 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 trajectory of the other vehicle included in the risk position information 112 instead of the predicted trajectory of the surrounding vehicle RV.

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

[0122] A specific example of display by the MID 105a and the HUD 105b will be described with reference to Fig. 18. When it is predicted that there is a possibility of a collision between the host vehicle 100 and the nearby vehicle RV, the processing unit 110 may display an icon shown in Fig. 18. Specifically, if the approaching direction of the nearby vehicle RV relative to the host vehicle 100 is within a range 600 ahead of the host vehicle 100 and the host vehicle 100 is about to turn left (for example, make a left turn), the processing unit 110 may display on the MID 105a that another vehicle is approaching from ahead of the host vehicle 100 and may display on the HUD 105b a warning to the area ahead of the host vehicle 100.

[0123] If the approaching direction of the nearby vehicle RV relative to the host vehicle 100 is within the range 601 to the right of the host vehicle 100, the processing unit 110 may display on the MID 105a that another vehicle is approaching from the right of the host vehicle 100 and display on the HUD 105b a warning to the right of the host vehicle 100. If the approaching direction of the nearby vehicle RV relative to the host vehicle 100 is within the range 601 to the left of the host vehicle 100, the processing unit 110 may display on the MID 105a that another vehicle is approaching from the left of the host vehicle 100 and display on the HUD 105b a warning to the left of the host vehicle 100.

[0124] <Summary of the embodiment> [Item 1] A driving assistance device (108), A storage means (111) for storing risk position information (112) representing a risk position where a vehicle (100) equipped with the driving assistance device may collide with another vehicle; an acquisition means (110a) for acquiring, from a surrounding vehicle (RV) present around the host vehicle, surrounding vehicle information indicating the speed, position, travel path, and yaw rate of the surrounding vehicle by vehicle-to-vehicle communication; a prediction means (110b) for predicting the possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating the speed, position, travel path, and yaw rate of the host vehicle and the surrounding vehicle information; and a notification means (110c) for notifying an occupant of the 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 determining a predicted trajectory (1010, 1510) of the host vehicle based on the host vehicle information, and determining a predicted trajectory (1021, 1520) of the surrounding vehicles based on the surrounding vehicle information; determining evaluation distances (1003, 1013, 1023, 1501, 1511, 1521) for evaluating an approaching state between the host vehicle and the peripheral vehicles based on the predicted trajectory of the host vehicle and the predicted trajectories of the peripheral vehicles; A driving assistance device that predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the evaluation distance is not within a predetermined range. According to this item, driving assistance for the vehicle can be performed appropriately. Specifically, excessive notification to the occupants can be suppressed. [Item 2] The prediction means determining a prediction accuracy of the predicted trajectory of the host vehicle based on a vehicle speed and a yaw rate of the host vehicle; determining a prediction accuracy of the predicted trajectory of the surrounding vehicle based on a vehicle speed and a yaw rate of the surrounding vehicle; 2. The driving assistance device according to claim 1, wherein a method for determining the evaluation distance is selected from a plurality of candidate determination methods based on the prediction accuracy of the predicted trajectory of the host vehicle, a radius of curvature of the predicted trajectory of the host vehicle, the prediction accuracy of the predicted trajectory of the surrounding vehicle, and a radius of curvature of the predicted trajectory of the surrounding vehicle. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 3] When the nearby vehicle is present within a first range (601) ahead of the host vehicle and the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater 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, a distance (1501) between the straight trajectory (1500) of the host vehicle and the surrounding vehicle is determined as the evaluation distance; 3. The driving assistance device according to claim 2, wherein if the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, a distance (1511) between the predicted trajectory (1510) of the host vehicle and the surrounding vehicle is determined as the evaluation distance. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 4] When the surrounding vehicle is present within the first range ahead 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 greater than the threshold accuracy, If the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or greater than the threshold radius, the distance (1501) between the straight trajectory (1500) of the host vehicle and the surrounding vehicle is determined as the evaluation distance; 4. The driving assistance device according to claim 3, wherein if the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, a 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, driving assistance for the vehicle can be performed more appropriately. [Item 5] 5. The driving assistance device according to claim 4, wherein the prediction means predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the surrounding vehicle is present within a first range ahead 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. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 6] When the surrounding vehicle is present within a second range (600) to the side of the host vehicle, the prediction means If the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than a threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is equal to or greater than a threshold radius, an intersection (1002) between the straight trajectory (1000) of the host vehicle and the straight trajectory (1001) of the surrounding vehicle is determined as a predicted intersection; If the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, an intersection (1012) between the predicted trajectory (1010) of the host vehicle and the straight trajectory (1011) of the surrounding vehicle is determined as a predicted intersection; 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 peripheral vehicle is equal to or greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the peripheral vehicle is equal to or greater than the threshold radius, determine an intersection (1002) between the straight trajectory (1000) of the host vehicle and the straight trajectory (1001) of the peripheral vehicle as a predicted intersection, 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 greater 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 (1022) of the straight trajectory (1020) of the host vehicle and the predicted trajectory (1021) of the surrounding vehicle is determined as a predicted intersection, 6. The driving assistance device according to any one of items 1 to 5, wherein the evaluation distance is determined based on the predicted intersection and a current position of the host vehicle. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 7] 7. The driving assistance device according to claim 6, wherein the prediction means predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the surrounding vehicle is present within the second range to 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. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 8] When the nearby vehicle is present within the second range to the side of the host vehicle, the prediction means determining an arrival time for the surrounding vehicle to arrive at the predicted intersection based on the surrounding vehicle information; predicting a possibility of a collision between the host vehicle and the surrounding vehicle when the arrival time is equal to or shorter than a first threshold time; 8. The driving assistance 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, driving assistance for the vehicle can be performed more appropriately. [Item 9] The prediction means repeatedly determining the predicted intersection point at predetermined time intervals; Item 9. The driving assistance device according to item 8, wherein the first threshold time is increased when the amount of change in the position of the predicted intersection is equal to or greater than a predetermined threshold change amount. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 10] The prediction means repeatedly determining at predetermined time intervals whether the nearby vehicle is present within a first range ahead of the host vehicle; 10. The driving assistance device according to any one of items 1 to 9, wherein the driving assistance device repeatedly determines at predetermined time intervals whether the nearby vehicle is present within a second range to the side of the host vehicle. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 11] The risk location information further includes a travel trajectory of another vehicle associated with the risk location, The driving assistance device according to any one of items 1 to 10, wherein the prediction means predicts the possibility of a 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 when the risk position is included within the predetermined distance in the traveling direction of the host vehicle. According to this item, driving assistance for the vehicle can be performed more appropriately. [Item 12] The notification means When a possibility of a collision between the host vehicle and the surrounding vehicle is predicted and the host vehicle performs a starting operation, a predetermined notification sound is used to notify the occupant; the host vehicle includes a first display means (105a) and a second display means (105b) provided at a position different from that of the first display means, The notification means displaying approach information including a warning to the occupant on the first display means; 12. The driving assistance device according to any one of items 1 to 11, wherein when it is predicted that there is a possibility of a collision between the host vehicle and the surrounding vehicle, the driving assistance device displays the approaching direction of the surrounding vehicle on the second display means. According to this item, the notification can be made in a way that is easy for the occupant to recognize. [Item 13] Item 13. The driving assistance device according to item 12, wherein the prediction means determines the approach direction of the peripheral vehicle based on a direction of the peripheral vehicle relative to the host vehicle and a rotation angle of a path of the peripheral vehicle relative to the path of the host vehicle. According to this item, the notification can be made in a way that is easy for the occupant to recognize. [Item 14] The right side or the left side of the road on which travel is mandatory in the area where the host vehicle is located is defined as a first side, and the opposite side to the first side is defined as a second side, and when it is predicted that there is a possibility of a collision between the host vehicle and the surrounding vehicle, the informing means If the approaching direction is within a first range ahead of the host vehicle and the host vehicle turns to the second side, displaying on the first display means that another vehicle is approaching from ahead of the host vehicle, and displaying on the second display means a warning to the area ahead of the host vehicle, If the approaching direction is within a second range on the first side of the host vehicle, displaying on the first display means that another vehicle is approaching from the first side of the host vehicle, and displaying on the second display means a warning to the first side of the host vehicle; Item 14. The driving assistance device according to item 13, wherein if the approaching direction is within a second range on the second side of the host vehicle, the first display means displays a message that another vehicle is approaching from the second side of the host vehicle, and the second display means displays a warning to the second side of the host vehicle. According to this item, the notification can be made in a way that is easy for the occupant to recognize. [Item 15] A driving assistance method, a storage step in which 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, from a surrounding vehicle (RV) present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the surrounding vehicle by vehicle-to-vehicle communication; a prediction step in which a prediction means predicts a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification step in which a notification means notifies an occupant of the host vehicle based on a prediction result by the prediction means, In the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, determining a predicted trajectory (1010, 1510) of the host vehicle based on the host vehicle information, and determining a predicted trajectory (1021, 1520) of the surrounding vehicles based on the surrounding vehicle information; determining evaluation distances (1003, 1013, 1023, 1501, 1511, 1521) for evaluating an approaching state between the host vehicle and the peripheral vehicles based on the predicted trajectory of the host vehicle and the predicted trajectories of the peripheral vehicles; A driving assistance method that predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the evaluation distance is not within a predetermined range. According to this item, driving assistance for the vehicle can be performed appropriately. Specifically, excessive notification to the occupants can be suppressed. [Item 16] On the computer, a storage step of storing risk position information (112) representing a risk position where the host vehicle (100) may collide with another vehicle; an acquisition step of acquiring, from a surrounding vehicle (RV) present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the surrounding vehicle by vehicle-to-vehicle communication; a prediction step of predicting a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification step of notifying an occupant of the host vehicle based on a 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, determining a predicted trajectory (1010, 1510) of the host vehicle based on the host vehicle information, and determining a predicted trajectory (1021, 1520) of the surrounding vehicles based on the surrounding vehicle information; determining evaluation distances (1003, 1013, 1023, 1501, 1511, 1521) for evaluating an approaching state between the host vehicle and the peripheral vehicles based on the predicted trajectory of the host vehicle and the predicted trajectories of the peripheral vehicles; The program predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the evaluation distance is not within a predetermined range. According to this item, driving assistance for the vehicle can be performed appropriately. Specifically, excessive notification to the occupants can be suppressed.

[0125] 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]

[0126] 100: vehicle, 101: sensor group, 102: turn signal lever, 103: GNSS antenna, 104: vehicle-to-vehicle communication antenna, 105: alarm device, 106: braking device, 107: turn signal, 108: control device

Claims

1. A driving assistance device, a storage means for storing risk position information indicating a risk position where a vehicle equipped with the driving assistance device is at risk of colliding with another vehicle; an acquisition means for acquiring, from a surrounding vehicle present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling path, and a yaw rate of the surrounding vehicle through vehicle-to-vehicle communication; a prediction means for predicting a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification means for notifying an occupant of the host vehicle based on a 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 determining a predicted trajectory of the host vehicle based on the host vehicle information, and determining predicted trajectories of the surrounding vehicles based on the surrounding vehicle information; determining an evaluation distance for evaluating an approach state between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle; If the evaluation distance is not within a predetermined range, it is predicted that there is no possibility of a collision between the host vehicle and the surrounding vehicle; The prediction means determining a prediction accuracy of the predicted trajectory of the host vehicle based on a vehicle speed and a yaw rate of the host vehicle; determining a prediction accuracy of the predicted trajectory of the surrounding vehicle based on a vehicle speed and a yaw rate of the surrounding vehicle; A driving assistance device that 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, a radius of curvature of the predicted trajectory of the host vehicle, the prediction accuracy of the predicted trajectory of the surrounding vehicle, and a radius of curvature of the predicted trajectory of the surrounding vehicle.

2. When the nearby vehicle is present within a first range ahead of the host vehicle and the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater 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, the distance between the straight trajectory of the host vehicle and the surrounding vehicle is determined as the evaluation distance; The driving assistance device according to claim 1 , wherein if the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, the distance between the predicted trajectory of the host vehicle and the surrounding vehicle is determined as the evaluation distance.

3. When the surrounding vehicle is present within the first range ahead 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 greater than the threshold accuracy, If the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or greater than the threshold radius, the distance between the straight trajectory of the host vehicle and the surrounding vehicle is determined as the evaluation distance; The driving assistance device according to claim 2 , wherein if the radius of curvature of the predicted trajectory of the nearby vehicle is less than the threshold radius, the distance between the predicted trajectory of the nearby vehicle and the host vehicle is determined as the evaluation distance.

4. 4. The driving assistance device according to claim 3, wherein the prediction means predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the surrounding vehicle is present within a first range ahead 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.

5. A driving assistance device, a storage means for storing risk position information indicating a risk position where a vehicle equipped with the driving assistance device is at risk of colliding with another vehicle; an acquisition means for acquiring, from a surrounding vehicle present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling path, and a yaw rate of the surrounding vehicle through vehicle-to-vehicle communication; a prediction means for predicting a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification means for notifying an occupant of the host vehicle based on a 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 determining a predicted trajectory of the host vehicle based on the host vehicle information, and determining predicted trajectories of the surrounding vehicles based on the surrounding vehicle information; determining an evaluation distance for evaluating an approach state between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle; If the evaluation distance is not within a predetermined range, it is predicted that there is no possibility of a collision between the host vehicle and the surrounding vehicle; When the nearby vehicle is present within a second range to the side of the host vehicle, the prediction means If the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than a threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is equal to or greater than a threshold radius, an intersection between the straight-line trajectory of the host vehicle and the straight-line trajectory of the surrounding vehicle is determined as a predicted intersection; if the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, determine an intersection between the predicted trajectory of the host vehicle and a straight trajectory of the surrounding vehicle as a predicted intersection; 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 greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or greater than the threshold radius, determine an intersection between the straight-line trajectory of the host vehicle and the straight-line trajectory of the surrounding vehicle as a predicted intersection; 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 greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, determine an intersection between the straight trajectory of the host vehicle and the predicted trajectory of the surrounding vehicle as a predicted intersection; A driving assistance device that determines the evaluation distance based on the predicted intersection and a current position of the host vehicle.

6. 6. The driving assistance device according to claim 5, wherein the prediction means predicts that there is no possibility of a collision between the host vehicle and the surrounding vehicle when the surrounding vehicle is present within the second range to 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.

7. When the nearby vehicle is present within the second range to the side of the host vehicle, the prediction means determining an arrival time for the surrounding vehicle to arrive at the predicted intersection based on the surrounding vehicle information; predicting a possibility of a collision between the host vehicle and the surrounding vehicle when the arrival time is equal to or shorter than a first threshold time; The driving assistance device according to claim 6 , wherein the first threshold time is determined based on a vehicle speed of the nearby vehicle.

8. The prediction means repeatedly determining the predicted intersection point at predetermined time intervals; The driving assistance device according to claim 7 , wherein the first threshold time is increased when an amount of change in the position of the predicted intersection is equal to or greater than a predetermined threshold change amount.

9. The prediction means repeatedly determining at predetermined time intervals whether the nearby vehicle is present within a first range ahead of the host vehicle; The driving assistance device according to claim 1 , wherein the device repeatedly determines at predetermined time intervals whether the nearby vehicle is present within a second range to the side of the host vehicle.

10. The risk location information further includes a travel trajectory of another vehicle associated with the risk location, 6. The driving assistance device according to claim 1, wherein the prediction means predicts the possibility of a 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 when the risk position is included within the predetermined distance in the direction of travel of the host vehicle.

11. The notification means When a possibility of a collision between the host vehicle and the surrounding vehicle is predicted and the host vehicle performs a starting operation, a predetermined notification sound is used to notify the occupant; the host vehicle includes a first display means and a second display means provided at a position different from that of the first display means, The notification means displaying approach information including a warning to the occupant on the first display means; 6. The driving assistance device according to claim 1, wherein when it is predicted that there is a possibility of a collision between the host vehicle and the nearby vehicle, the second display means displays the approaching direction of the nearby vehicle.

12. 12. The driving assistance device according to claim 11, wherein the prediction means determines the approach direction of the nearby vehicle based on a direction of the nearby vehicle relative to the host vehicle and a rotation angle of a path of the nearby vehicle relative to the path of the host vehicle.

13. The right side or the left side of the road on which travel is mandatory in the area where the host vehicle is located is defined as a first side, and the opposite side to the first side is defined as a second side, and when it is predicted that there is a possibility of a collision between the host vehicle and the nearby vehicle, the informing means If the approaching direction is within a first range ahead of the host vehicle and the host vehicle turns to the second side, displaying on the first display means that another vehicle is approaching from ahead of the host vehicle, and displaying on the second display means a warning to the area ahead of the host vehicle, If the approaching direction is within a second range on the first side of the host vehicle, displaying on the first display means that another vehicle is approaching from the first side of the host vehicle, and displaying on the second display means a warning to the first side of the host vehicle; 13. The driving assistance device according to claim 12, wherein 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 the second side of the host vehicle.

14. A driving assistance method, a storage step in which storage means stores risk position information indicating a risk position where there is a risk of the host vehicle colliding with another vehicle; an acquisition step in which an acquisition unit acquires, from a surrounding vehicle present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling path, and a yaw rate of the surrounding vehicle through vehicle-to-vehicle communication; a prediction step in which a prediction means predicts a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification step in which a notification means notifies an occupant of the host vehicle based on a prediction result by the prediction means, In the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, determining a predicted trajectory of the host vehicle based on the host vehicle information, and determining predicted trajectories of the surrounding vehicles based on the surrounding vehicle information; determining an evaluation distance for evaluating an approach state between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle; If the evaluation distance is not within a predetermined range, it is predicted that there is no possibility of a collision between the host vehicle and the surrounding vehicle; In the prediction step, determining a prediction accuracy of the predicted trajectory of the host vehicle based on a vehicle speed and a yaw rate of the host vehicle; determining a prediction accuracy of the predicted trajectory of the surrounding vehicle based on a vehicle speed and a yaw rate of the surrounding vehicle; A driving assistance method that 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, a radius of curvature of the predicted trajectory of the host vehicle, the prediction accuracy of the predicted trajectory of the surrounding vehicle, and a radius of curvature of the predicted trajectory of the surrounding vehicle.

15. A driving assistance method, comprising: a storage step in which storage means stores risk position information indicating a risk position where there is a risk of the host vehicle colliding with another vehicle; an acquisition step in which an acquisition unit acquires, from a surrounding vehicle present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling path, and a yaw rate of the surrounding vehicle through vehicle-to-vehicle communication; a prediction step in which a prediction means predicts a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification step in which a notification means notifies an occupant of the host vehicle based on a prediction result by the prediction means, In the prediction step, when the risk position is not included within a predetermined distance in the traveling direction of the host vehicle, determining a predicted trajectory of the host vehicle based on the host vehicle information, and determining predicted trajectories of the surrounding vehicles based on the surrounding vehicle information; determining an evaluation distance for evaluating an approach state between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle; If the evaluation distance is not within a predetermined range, it is predicted that there is no possibility of a collision between the host vehicle and the surrounding vehicle; In the prediction step, when the nearby vehicle is present within a second range to the side of the host vehicle, If the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than a threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is equal to or greater than a threshold radius, an intersection between the straight-line trajectory of the host vehicle and the straight-line trajectory of the surrounding vehicle is determined as a predicted intersection; if the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, determine an intersection between the predicted trajectory of the host vehicle and a straight trajectory of the surrounding vehicle as a predicted intersection; 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 greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or greater than the threshold radius, determine an intersection between the straight-line trajectory of the host vehicle and the straight-line trajectory of the surrounding vehicle as a predicted intersection; 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 greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, determine an intersection between the straight trajectory of the host vehicle and the predicted trajectory of the surrounding vehicle as a predicted intersection; The driving assistance method further comprises determining the evaluation distance based on the predicted intersection and a current position of the host vehicle.

16. On the computer, a storage step of storing risk position information indicating a risk position where there is a risk of the host vehicle colliding with another vehicle; an acquisition step of acquiring, from a surrounding vehicle present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the surrounding vehicle by vehicle-to-vehicle communication; a prediction step of predicting a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification step of notifying an occupant of the host vehicle based on a 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, determining a predicted trajectory of the host vehicle based on the host vehicle information, and determining predicted trajectories of the surrounding vehicles based on the surrounding vehicle information; determining an evaluation distance for evaluating an approach state between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle; If the evaluation distance is not within a predetermined range, it is predicted that there is no possibility of a collision between the host vehicle and the surrounding vehicle; In the prediction step, determining a prediction accuracy of the predicted trajectory of the host vehicle based on a vehicle speed and a yaw rate of the host vehicle; determining a prediction accuracy of the predicted trajectory of the surrounding vehicle based on a vehicle speed and a yaw rate of the surrounding vehicle; A program that 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, a radius of curvature of the predicted trajectory of the host vehicle, the prediction accuracy of the predicted trajectory of the surrounding vehicle, and a radius of curvature of the predicted trajectory of the surrounding vehicle.

17. A computer comprising: a storage step of storing risk position information indicating a risk position where there is a risk of the host vehicle colliding with another vehicle; an acquisition step of acquiring, from a surrounding vehicle present around the host vehicle, surrounding vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the surrounding vehicle by vehicle-to-vehicle communication; a prediction step of predicting a possibility of a collision between the host vehicle and the surrounding vehicle based on host vehicle information indicating a vehicle speed, a position, a traveling trajectory, and a yaw rate of the host vehicle and the surrounding vehicle information; a notification step of notifying an occupant of the host vehicle based on a 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, determining a predicted trajectory of the host vehicle based on the host vehicle information, and determining predicted trajectories of the surrounding vehicles based on the surrounding vehicle information; determining an evaluation distance for evaluating an approach state between the host vehicle and the peripheral vehicle based on the predicted trajectory of the host vehicle and the predicted trajectory of the peripheral vehicle; If the evaluation distance is not within a predetermined range, it is predicted that there is no possibility of a collision between the host vehicle and the surrounding vehicle; In the prediction step, when the nearby vehicle is present within a second range to the side of the host vehicle, If the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than a threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is equal to or greater than a threshold radius, an intersection between the straight-line trajectory of the host vehicle and the straight-line trajectory of the surrounding vehicle is determined as a predicted intersection; if the prediction accuracy of the predicted trajectory of the host vehicle is equal to or greater than the threshold accuracy and the radius of curvature of the predicted trajectory of the host vehicle is less than the threshold radius, determine an intersection between the predicted trajectory of the host vehicle and a straight trajectory of the surrounding vehicle as a predicted intersection; 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 greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is equal to or greater than the threshold radius, determine an intersection between the straight-line trajectory of the host vehicle and the straight-line trajectory of the surrounding vehicle as a predicted intersection; 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 greater than the threshold accuracy, and the radius of curvature of the predicted trajectory of the surrounding vehicle is less than the threshold radius, determine an intersection between the straight trajectory of the host vehicle and the predicted trajectory of the surrounding vehicle as a predicted intersection; A program that determines the evaluation distance based on the predicted intersection and the current position of the host vehicle.

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