Vehicle control device, vehicle control method, and vehicle control computer program

Abstract

To provide a vehicle controller capable of setting a target traveling track with high safety.SOLUTION: A vehicle controller comprises: a storage part (4, 22) for storing traveling track distribution information indicating a traveling track distribution for every lane in a predetermined section of a road; a track setting part 32 for setting a target traveling track of a vehicle 10 by referring to the traveling track distribution information about another lane different from one's own lane on which the vehicle 10 travels, when the vehicle 10 travels in the predetermined section; and a vehicle control part 33 by which the vehicle 10 is made to travel along the target traveling track.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a computer program for vehicle control.

Background Art

[0002] In a system for automatically controlling a vehicle, a technique has been proposed in which a travel locus when the vehicle actually travels during manual driving is recorded, and during automatic driving, the vehicle is caused to travel with reference to the recorded travel locus (see Patent Document 1).

[0003] The vehicle travel control device disclosed in Patent Document 1 creates a travel locus of the host vehicle from the history of the position of the host vehicle during manual driving, and sets the created travel locus as the target locus of the host vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, a vehicle under manual driving control does not always travel so as to draw an ideal travel locus. Depending on the road section, the vehicle may travel so as to draw a travel locus that deviates from the lane in which the vehicle is traveling, or the travel locus of each vehicle may vary. Therefore, even if a target travel locus (hereinafter simply referred to as a target travel locus) is set based on the travel locus of a vehicle under manual driving control, there is a risk that the set target locus may not be a safe locus.

[0006] Therefore, an object of the present invention is to provide a vehicle control device capable of setting a highly safe target travel locus.

Means for Solving the Problems

[0007] According to one embodiment, a vehicle control device is provided. This vehicle control device includes a storage unit that stores travel trajectory distribution information representing the distribution of travel trajectories for each lane in a predetermined section of a road, and a trajectory setting unit that refers to the travel trajectory distribution information for lanes other than the own lane on which the vehicle travels when the vehicle travels in the predetermined section, and sets a target travel trajectory of the vehicle, and a vehicle control unit that causes the vehicle to travel along the target travel trajectory.

[0008] In this vehicle control device, the travel trajectory distribution information includes a plurality of travel trajectories for each lane in a predetermined section, and it is preferable that the trajectory setting unit sets the target travel trajectory so as to be separated from any of the plurality of travel trajectories included in the travel trajectory distribution information for other lanes by a predetermined interval or more.

[0009] Alternatively, in this vehicle control device, the travel trajectory distribution information includes a reference travel trajectory and a variation index value representing the degree of variation of the travel trajectories, and it is preferable that the trajectory setting unit sets the target travel trajectory so as to be farther away from the reference travel trajectory of other lanes as the variation index value included in the travel trajectory distribution information for other lanes becomes larger.

[0010] In this case, it is preferable that the trajectory setting unit refers to the travel trajectory distribution information, identifies the lane in which the variation index value is the smallest in a predetermined section, and sets the target travel trajectory from the current position of the vehicle until it reaches the predetermined section so that the vehicle moves to the identified lane before reaching the predetermined section.

[0011] According to another embodiment, a vehicle control device is provided. This vehicle control device includes a storage unit that stores a reference travel trajectory for each lane in a predetermined section of a road, and a selection unit that selects the lane in which the most safe reference travel trajectory is shown among the reference travel trajectories of each lane in the traveling direction of the vehicle when the vehicle travels in the predetermined section, and a vehicle control unit that causes the vehicle to travel along the reference travel trajectory of the selected lane.

[0012] In this vehicle control device, it is preferable that the selection unit determines that the safety of the reference driving trajectory in which the position of the lane when entering a predetermined section is the same as the position of the lane when exiting the predetermined section is higher than the safety of the reference driving trajectory in which the position of the lane when entering the predetermined section is different from the position of the lane when exiting the predetermined section among the reference driving trajectories of each lane in the traveling direction of the vehicle.

[0013] Moreover, it is preferable that this vehicle control device further includes a self-lane detection unit that detects the self-lane in which the vehicle is traveling. And when the self-lane is different from the selected lane, it is preferable that the vehicle control unit controls the vehicle to move to the selected lane before the vehicle reaches a predetermined section.

[0014] According to still another embodiment, a vehicle control method is provided. This vehicle control method includes, when the vehicle travels through a predetermined section of a road, setting a target driving trajectory of the vehicle by referring to the driving trajectory distribution information about other lanes different from the self-lane in which the vehicle is traveling among the driving trajectory distribution information representing the distribution of driving trajectories for each lane in the predetermined section, and causing the vehicle to travel along the target driving trajectory.

[0015] According to still another embodiment, a vehicle control computer program is provided. This vehicle control computer program includes instructions for causing a processor mounted on the vehicle to set a target driving trajectory of the vehicle by referring to the driving trajectory distribution information about other lanes different from the self-lane in which the vehicle is traveling among the driving trajectory distribution information representing the distribution of driving trajectories for each lane in a predetermined section when the vehicle travels through the predetermined section of the road, and causing the vehicle to travel along the target driving trajectory.

Advantages of the Invention

[0016] The vehicle control device according to the present disclosure has an effect that a highly safe target driving trajectory can be set.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0018] Hereinafter, with reference to the drawings, a vehicle control device, a vehicle control method executed on the vehicle control device, and a vehicle control computer program will be described. This vehicle control device uses driving trajectory distribution information representing the distribution of driving trajectories for each lane when various vehicles actually travel on a predetermined section of a road for setting the target driving trajectory of the vehicle. The distribution of driving trajectories may include non-ideal driving trajectories for various reasons. By setting the target driving trajectory in this way, this vehicle control device can perform automatic driving control of the vehicle in consideration of information on non-ideal driving trajectories in order to make the vehicle travel more safely. Alternatively, this vehicle control device refers to the reference driving trajectories for each lane, selects the lane in which the reference driving trajectory with the highest safety is shown, and makes the vehicle travel along the reference driving trajectory of the selected lane.

[0019] FIG. 1 is a schematic configuration diagram of a vehicle control system in which a vehicle control device is implemented. FIG. 2 is a hardware configuration diagram of an electronic control unit which is an embodiment of the vehicle control device. In the present embodiment, a vehicle control system 1 mounted on a vehicle 10 and controlling the vehicle 10 includes a camera 2, a GPS receiver 3, a storage device 4, and an electronic control unit (ECU) 5 which is an example of the vehicle control device. The camera 2, the GPS receiver 3, the storage device 4, and the ECU 5 are communicably connected via an in-vehicle network conforming to a standard such as a controller area network. Note that the vehicle control system 1 may further include a distance measuring sensor (not shown) such as LiDAR or radar for measuring the distance from the vehicle 10 to an object existing around the vehicle 10. Further, the vehicle control system 1 may include a wireless communication terminal (not shown) for wirelessly communicating with a device outside the vehicle 10. Furthermore, the vehicle control system 1 may include a navigation device (not shown) for searching for a planned travel route to a destination.

[0020] The camera 2 is an example of a sensor that generates a sensor signal representing the surroundings of the vehicle 10, and includes a two-dimensional detector composed of an array of photoelectric conversion elements sensitive to visible light, such as a CCD or a C-MOS, and an imaging optical system that forms an image of an area to be photographed on the two-dimensional detector. The camera 2 is attached, for example, inside the passenger compartment of the vehicle 10 so as to face the front of the vehicle 10. The camera 2 photographs the front area of the vehicle 10 at a predetermined photographing cycle (for example, 1 / 30 second to 1 / 10 second), and generates an image in which the front area is shown. The image obtained by the camera 2 is an example of a sensor signal. Note that the vehicle 10 may be provided with a plurality of cameras having different photographing directions or focal lengths.

[0021] Each time the camera 2 generates an image, the generated image is output to the ECU 5 via the in-vehicle network.

[0022] The GPS receiver 3 receives GPS signals from GPS satellites at a predetermined cycle, and determines the vehicle 10's own position based on the received GPS signals. Then, the GPS receiver 3 outputs positioning information representing the result of determining the vehicle 10's own position based on the GPS signals to the ECU 5 via the in-vehicle network at a predetermined cycle. Note that the vehicle 10 may have a receiver that receives positioning signals from satellites by another satellite positioning system instead of the GPS receiver to determine the vehicle 10's own position.

[0023] The storage device 4 is an example of a storage unit and includes, for example, a hard disk device, a non-volatile semiconductor memory, or an optical recording medium and its access device. Then, the storage device 4 stores a highly accurate map used for the automatic driving control of the vehicle 10. The highly accurate map includes, for example, information representing the number of lanes, road markings such as lane dividing lines or stop lines, for each road section included in a predetermined area represented by the highly accurate map. Further, the highly accurate map includes, for each road section, information for determining whether it corresponds to a predetermined section, such as the curvature of the road section, the presence or absence of intersections, merging points, or branching points, and points where the vehicle enters or exits. Further, the highly accurate map includes, for a predetermined section, running trajectory distribution information for each lane of the road section. The running trajectory distribution information includes information representing a plurality of running trajectories for each lane. Further, the running trajectory distribution information may include information representing a reference running trajectory for each lane and a variation index value representing the degree of variation of the running trajectories for each lane.

[0024] Note that the reference driving trajectory for each individual lane is the standard trajectory that a vehicle passes through when driving in that lane, provided there are no special circumstances. For example, the reference driving trajectory is set as the average of the driving trajectories of a plurality of vehicles that have actually driven in that lane. Alternatively, the reference driving trajectory may be set to pass through the center of that lane. Also, the variation index value can be the variance value in the width direction of the lane for a plurality of driving trajectories in one lane. Alternatively, the variation index value may be the maximum value of the differences in positions in the width direction of the lane between those plurality of driving trajectories, or the distance between the driving trajectory that is farthest from the reference driving trajectory in the width direction of the lane and the reference driving trajectory among the plurality of driving trajectories.

[0025] Also, as in the case where an intersection is included in a predetermined section, even if vehicle 10 enters the predetermined section from the same side, there may be a plurality of selectable exit destinations from the predetermined section. In such a case, the reference driving trajectory and the variation index value are set for each exit destination. For example, assume that an intersection which is a crossroads is included in a predetermined section, and at one end of the predetermined section, there are lanes where straight-ahead and left-turn are possible, a lane where only straight-ahead is possible, and a lane where straight-ahead and right-turn are possible. In this case, the high-precision map includes information representing the reference driving trajectory for a vehicle going straight and information representing the reference driving trajectory for a vehicle turning left, and the corresponding variation index values, for the lane where straight-ahead and left-turn are possible. Also, for the lane where only straight-ahead is possible, the high-precision map includes information representing the reference driving trajectory for a vehicle going straight and the variation index value. Further, for the lane where straight-ahead and right-turn are possible, the high-precision map includes information representing the reference driving trajectory for a vehicle going straight and information representing the reference driving trajectory for a vehicle turning right, and the corresponding variation index values. Similarly, when the predetermined section includes a branching point, the high-precision map includes information representing the reference driving trajectory and the variation index value for each possible direction of travel at that branching point for each lane.

[0026] Furthermore, the storage device 4 may have a processor for executing processes such as the update process of the high-precision map and the process related to the read request of the high-precision map from the ECU 5. And the storage device 4 may, for example, transmit a request for acquiring a high-precision map together with the current position of the vehicle 10 to a map server (not shown) via a wireless communication terminal (not shown) every time the vehicle 10 moves a predetermined distance. Also, the storage device 4 may receive a high-precision map for a predetermined area around the current position of the vehicle 10 from the map server via the wireless communication terminal. Furthermore, when receiving a read request for the high-precision map from the ECU 5, the storage device 4 cuts out a range relatively narrower than the above-mentioned predetermined area including the current position of the vehicle 10 from the stored high-precision map and outputs it to the ECU 5 via the in-vehicle network.

[0027] The ECU 5 controls the automatic driving of the vehicle 10. In the present embodiment, the ECU 5 sets a target travel trajectory with reference to the travel trajectory distribution information of a predetermined section in the traveling direction of the vehicle 10, and causes the vehicle 10 to travel along the set target travel trajectory.

[0028] As shown in FIG. 2, the ECU 5 includes a communication interface 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 may each be configured as separate circuits, or may be integrally configured as one integrated circuit.

[0029] The communication interface 21 has an interface circuit for connecting the ECU 5 to the in-vehicle network. And every time the communication interface 21 receives an image from the camera 2, it passes the received image to the processor 23. Also, every time the communication interface 21 receives positioning information from the GPS receiver 3, it passes the positioning information to the processor 23. Furthermore, the communication interface 21 passes the high-precision map read from the storage device 4 to the processor 23.

[0030] The memory 22 is another example of the storage unit and has, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in the vehicle control process executed by the processor 23. For example, the memory 22 stores parameters of the camera 2 such as the focal length, shooting direction, and mounting position of the camera 2, and various parameters for specifying an identifier for object detection used for detecting ground features and the like. Further, the memory 22 stores the positioning information of the vehicle 10, images around the vehicle 10, and a high-precision map. Furthermore, the memory 22 temporarily stores various data generated during the vehicle control process.

[0031] The processor 23 includes one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logical arithmetic unit, a numerical arithmetic unit, or a graphic processing unit. And the processor 23 executes vehicle control processing for the vehicle 10 at a predetermined cycle.

[0032] (First Embodiment) Hereinafter, the vehicle control process according to the first embodiment will be described. In the vehicle control process according to the first embodiment, the processor 23 sets a target driving trajectory by referring to the driving trajectory distribution information of other lanes different from the own lane in which the vehicle 10 is traveling. More specifically, based on the driving trajectory distribution information of other lanes, the processor 23 sets a target driving trajectory to move away from other lanes when it is assumed that other vehicles (hereinafter sometimes referred to as surrounding vehicles) traveling in other lanes approach or protrude into the own lane.

[0033] FIG. 3 is a functional block diagram of the processor 23 related to vehicle control processing according to the first embodiment. The processor 23 includes a host lane detection unit 31, a trajectory setting unit 32, and a vehicle control unit 33. Each of these units included in the processor 23 is a functional module realized by, for example, a computer program operating on the processor 23. Alternatively, each of these units included in the processor 23 may be a dedicated arithmetic circuit provided in the processor 23.

[0034] The host lane detection unit 31 detects the host lane by comparing an image representing the surroundings of the vehicle 10 (hereinafter sometimes simply referred to as an image) generated by the camera 2 with a high-precision map. For example, the host lane detection unit 31 projects the features on or around the road detected from the image onto the high-precision map assuming the position and orientation of the vehicle 10, or projects the features on or around the road around the vehicle 10 represented in the high-precision map onto the image. Note that the features on or around the road can be, for example, road markings such as lane dividing lines or stop lines, or curbstones. Then, the host lane detection unit 31 estimates the position and orientation of the vehicle 10 when the features detected from the image and the features represented on the high-precision map match the most as the self-position of the vehicle 10.

[0035] The host lane detection unit 31 may determine the position where the features are projected on the high-precision map or the image using the initial values of the assumed position and orientation of the vehicle 10 and the parameters of the camera 2 such as the focal length, installation height, and shooting direction. Note that as the initial values of the position and orientation of the vehicle 10, the position of the vehicle 10 measured by the GPS receiver 3, or the position and orientation of the vehicle 10 estimated at the previous host lane detection corrected using the odometry information is used. Then, the host lane detection unit 31 calculates the degree of coincidence (for example, the reciprocal of the sum of the squares of the distances between the corresponding features) between the features on or around the road detected from the image and the corresponding features represented on the high-precision map.

[0036] The own-lane detection unit 31 repeats the above processing while changing the assumed position and orientation of the vehicle 10. Then, the own-lane detection unit 31 may estimate the assumed position and orientation at the time when the degree of coincidence is maximized as the actual self-position of the vehicle 10. Then, the own-lane detection unit 31 may specify, with reference to the high-precision map, the lane including the self-position of the vehicle 10 as the own-lane on which the vehicle 10 is traveling.

[0037] Note that the own-lane detection unit 31 may detect the object to be detected, for example, by inputting an image into a discriminator pre-trained to detect the object from the image. As such a discriminator, the own-lane detection unit 31 can use a deep neural network (DNN) having a convolutional neural network (CNN)-type architecture such as Single Shot MultiBox Detector or Faster R-CNN. Alternatively, the own-lane detection unit 31 may use a DNN having a self attention network (SAN)-type architecture such as Vision Transformer as such a discriminator.

[0038] The own-lane detection unit 31 notifies the trajectory setting unit 32 of the information representing the detected own-lane.

[0039] The trajectory setting unit 32 sets a target travel trajectory with reference to the travel trajectory distribution information for a predetermined section existing between the current position of the vehicle 10 and a point ahead by a predetermined distance (for example, several hundred meters to several kilometers) in the traveling direction of the vehicle 10.

[0040] The predetermined section may be, for example, a curve section having a curvature equal to or greater than a predetermined value, or a road section including an intersection. Alternatively, the predetermined section may be a road section including a merging point where the vehicle merges with another road, or a road section facing a vehicle entrance such as an entrance and exit of a parking lot. Note that the predetermined section is not limited to these road sections and may be a simple straight road section. Alternatively, the road section itself in which the travel trajectory distribution information is included in the high-precision map may be the predetermined section.

[0041] The trajectory setting unit 32 refers to the high-precision map and identifies a predetermined section existing between the current position of the vehicle 10 and a point at a predetermined distance ahead along the traveling direction of the vehicle 10. Then, the trajectory setting unit 32 refers to the traveling trajectory distribution information of other lanes than the own lane, particularly the traveling trajectory distribution information of the adjacent lane adjacent to the own lane, among the traveling trajectory distribution information of the predetermined section included in the high-precision map. Note that the adjacent lane is not limited to a parallel lane through which surrounding vehicles traveling in the same direction as the traveling direction of the vehicle 10 can pass, and may be an oncoming lane. Then, the trajectory setting unit 32 sets a target traveling trajectory so as to be separated from any of the plurality of traveling trajectories of other lanes by a predetermined interval or more. Further, the trajectory setting unit 32 sets a target traveling trajectory so that the deviation amount from the center of the own lane or the reference traveling trajectory is minimized as long as it is separated from any of the plurality of traveling trajectories of other lanes by a predetermined interval or more.

[0042] In the traveling trajectory distribution information of other lanes, if there are abnormal traveling trajectories that are close to the own lane or protrude into the own lane, it is assumed that surrounding vehicles traveling in other lanes may approach or protrude into the own lane. Therefore, by setting the target traveling trajectory as described above, it is possible to maintain a certain distance from such surrounding vehicles even if they exist.

[0043] FIG. 4(a) and FIG. 4(b) are diagrams each showing an example of the relationship between the distribution of traveling trajectories in the adjacent lane and the target traveling trajectory. In the examples shown in FIG. 4(a) and FIG. 4(b), the vehicle 10 is traveling in the right lane 402 out of the two lanes 401 and 402 provided on the road 400. That is, the lane 402 is the own lane. Therefore, in order to set the target traveling trajectory, the traveling trajectory distribution information of the left lane 401 is referred to.

[0044] In the example shown in FIG. 4(a), the variation of the plurality of travel trajectories 410 included in the travel trajectory distribution information of lane 401 is relatively small, and each travel trajectory passes near the center of lane 401. Therefore, the target travel trajectory 420 set to be separated from each travel trajectory by a predetermined interval or more is also set to pass near the center of the own lane 402.

[0045] In the example shown in FIG. 4(b), among the plurality of travel trajectories 410 included in the travel trajectory distribution information of lane 401, the travel trajectory 410a passes through a position close to the boundary between the own lane 402 and lane 401. Therefore, the closer the travel trajectory 410a is to the own lane 402, the more the target travel trajectory 430 is set to pass through a position farther from the center of the own lane 402 and away from lane 401.

[0046] As described above, in the travel trajectory distribution information, for each lane, a reference travel trajectory for that lane and a variation index value representing the degree of variation of the travel trajectories may be included. In this case, the trajectory setting unit 32 may set the target travel trajectory to be farther from the reference travel trajectory of the other lane as the variation index value of the other lane becomes larger. For example, when the variation index value of the adjacent lane is equal to or less than a predetermined variation threshold, the trajectory setting unit 32 sets the reference travel trajectory of the own lane as the target trajectory. Also, when the variation index value of the adjacent lane becomes larger than a predetermined variation index value, the trajectory setting unit 32 sets the target travel trajectory to pass through a position shifted by an offset distance corresponding to the variation index value of the adjacent lane in a direction away from the adjacent lane compared to the reference travel trajectory of the own lane. Thereby, the target travel trajectory is set to be farther from the reference travel trajectory of the adjacent lane with a large variation index value. Also in this case, similar to the above example, the trajectory setting unit 32 can set a target travel trajectory that can maintain a certain distance from the vehicle 10 even when a surrounding vehicle traveling in another lane approaches or protrudes into the own lane.

[0047] In addition, there may be multiple possible traveling directions for the own lane and other lanes, such as when an intersection is included in a predetermined section. In such a case, the trajectory setting unit 32 may execute the above processing by referring to the reference driving trajectory and the variation index value set for the other lane in the same direction (in the case of a parallel lane) or the opposite direction (in the case of an oncoming lane) as the direction in which the vehicle 10 travels in the own lane. Note that the trajectory setting unit 32 may identify the direction in which the vehicle 10 travels in a predetermined section by referring to the planned driving route of the vehicle 10 received from a navigation device (not shown).

[0048] When the trajectory setting unit 32 sets the target driving trajectory, it notifies the set target driving trajectory to the vehicle control unit 33.

[0049] The vehicle control unit 33 controls each part of the vehicle 10 so that the vehicle 10 travels along the target driving trajectory received from the trajectory setting unit 32. For this purpose, the vehicle control unit 33 measures the position of the vehicle 10 at a predetermined cycle and compares the measured position of the vehicle 10 with the target driving trajectory. Note that the vehicle control unit 33 may measure the accurate position of the vehicle 10 by collating the image obtained by the camera 2 with the high-precision map in the same manner as described for the own lane detection unit 31. Then, if the measured position of the vehicle 10 is on the target driving trajectory, the vehicle control unit 33 determines the steering angle of the vehicle 10 so that the vehicle 10 travels along the target driving trajectory, and controls the steering of the vehicle 10 to the determined steering angle. Also, if the measured position of the vehicle 10 is away from the target driving trajectory, the vehicle control unit 33 determines the steering angle of the vehicle 10 so that the vehicle 10 approaches the target driving trajectory, and controls the steering of the vehicle 10 to the determined steering angle.

[0050] Further, the vehicle control unit 33 sets the acceleration and deceleration of the vehicle 10 so that the inter-vehicle distance between the vehicle 10 and another vehicle traveling ahead thereof is maintained at a certain distance or more. To this end, the vehicle control unit 33 inputs the image obtained by the camera 2 or the distance measurement signal obtained by a distance measurement sensor (not shown) into a discriminator that has been pre-trained to detect other vehicles, thereby detecting other vehicles. Then, the vehicle control unit 33 estimates the distance between the vehicle 10 and the other vehicle based on the size of the other vehicle in the image, or based on the position of the lower end of the area representing the other vehicle, or based on the distance indicated in the distance measurement signal in the direction of the detected other vehicle. When the inter-vehicle distance between the vehicle 10 and the other vehicle becomes less than a predetermined distance threshold, the vehicle control unit 33 sets the acceleration and deceleration of the vehicle 10 so as to decelerate the vehicle 10. On the other hand, if the inter-vehicle distance between the vehicle 10 and the other vehicle is equal to or greater than the predetermined distance threshold, the vehicle control unit 33 maintains the speed of the vehicle 10 constant or sets the acceleration and deceleration of the vehicle 10 so as to approach the speed limit of the road on which the vehicle 10 is traveling or the target speed set by the driver. Then, the vehicle control unit 33 sets the accelerator opening or the brake amount according to the set acceleration and deceleration. The vehicle control unit 33 obtains the fuel injection amount according to the set accelerator opening and outputs a control signal corresponding to the fuel injection amount to the fuel injection device of the engine of the vehicle 10. Alternatively, the vehicle control unit 33 obtains the amount of electric power supplied to the motor according to the set accelerator opening and controls the drive circuit of the motor so that the amount of electric power is supplied to the motor. Alternatively, the vehicle control unit 33 outputs a control signal corresponding to the set brake amount to the brake of the vehicle 10.

[0051] FIG. 5 is an operation flowchart of vehicle control processing according to the first embodiment, which is executed by the processor 23. The processor 23 may execute the vehicle control processing according to the following operation flowchart at a predetermined cycle.

[0052] The own-lane detection unit 31 of the processor 23 detects the own lane in which the vehicle 10 is traveling (step S101).

[0053] Also, the trajectory setting unit 32 of the processor 23 refers to the driving trajectory distribution information of other lanes than the own lane for a predetermined section existing up to a point at a predetermined distance ahead in the traveling direction of the vehicle 10, and sets a target driving trajectory in the own lane so as to be separated from any driving trajectory of other lanes by a predetermined interval or more (step S102). Note that, as described above, the trajectory setting unit 32 may set the target driving trajectory so as to be separated from the reference driving trajectory of other lanes as the variation index value in other lanes becomes larger.

[0054] The vehicle control unit 33 of the processor 23 controls each part of the vehicle 10 so that the vehicle 10 travels along the target driving trajectory (step S103). Then, the processor 23 ends the vehicle control process.

[0055] As described above, this vehicle control device uses the driving trajectory distribution information of other lanes for setting the target driving trajectory of the vehicle. Therefore, this vehicle control device can set a highly safe target driving trajectory in consideration of the possible trajectories of surrounding vehicles traveling in other lanes.

[0056] Note that in the driving trajectory distribution information, in a section where it is shown that the degree of variation of the driving trajectories of other lanes is large, it is assumed that surrounding vehicles traveling in other lanes may inadvertently approach the own lane. Therefore, according to a modification example, the vehicle control unit 33 gives a warning indicating that there is a possibility that surrounding vehicles approach the vehicle 10 in a section where the variation index value in other lanes than the own lane is equal to or more than a predetermined threshold value, to the driver via a display device (not shown) or a speaker (not shown) provided in the vehicle interior.

[0057] Also, for a section where it is shown that the degree of variation in the driving trajectory for the own lane is large in the driving trajectory distribution information, it is assumed that there is a possibility that some disturbance is applied during the driving of the vehicle 10. Therefore, the vehicle control unit 33 may notify the driver via a display device or a speaker provided in the vehicle interior of a warning indicating a warning about the driving of the vehicle 10 also for a section where the variation index value in the own lane is equal to or greater than a predetermined threshold value.

[0058] According to another modification, the trajectory setting unit 32 may set a target driving trajectory so that a lane with a smaller variation index value is prioritized among the lanes in the traveling direction of the vehicle 10 in a predetermined section. For example, the trajectory setting unit 32 identifies a lane with the smallest variation index value among the lanes in which the vehicle 10 can move until the vehicle 10 reaches a predetermined section among the lanes in the traveling direction of the vehicle 10. Then, the trajectory setting unit 32 sets a target driving trajectory from the current position of the vehicle 10 represented by the latest positioning information until the vehicle 10 reaches a predetermined section so that the vehicle 10 moves to the identified lane until the vehicle 10 reaches the predetermined section. Then, for a predetermined section, the trajectory setting unit 32 may set a target driving trajectory according to the above-described embodiment or modification. Note that the distance required for one lane change (hereinafter referred to as the lane change distance) may be stored in advance in the memory 22. Then, the trajectory setting unit 32 refers to the high-precision map to obtain the distance from the current position of the vehicle 10 to a predetermined section, and sets the number obtained by dividing the distance by the lane change distance as the maximum number of lane changes that can be executed until the vehicle 10 reaches the predetermined section. The trajectory setting unit 32 may set the individual lanes that can be moved by lane changes within the maximum number of lane changes from the own lane as the lanes in which the vehicle 10 can move until the vehicle 10 reaches a predetermined section. According to this modification, the trajectory setting unit 32 can set a target driving trajectory so that the vehicle 10 can travel while avoiding a lane where a disturbance is likely to occur.

[0059] (Second Embodiment) Next, the vehicle control process according to the second embodiment will be described. In the vehicle control process according to the second embodiment, the processor 23 refers to the reference driving trajectory for each lane and selects the lane in which the reference driving trajectory with the highest safety is shown as the target lane. Then, the processor 23 drives the vehicle 10 along the reference driving trajectory of the selected target lane.

[0060] The vehicle control process according to the second embodiment is different in part from the vehicle control process according to the first embodiment in the process executed by the processor 23. Therefore, the differences from the first embodiment will be described below.

[0061] In the second embodiment, the high-precision map includes information representing the reference driving trajectory for each lane for a predetermined section. Note that the predetermined section in the second embodiment can be the same road section as the predetermined section in the first embodiment. Also, in the second embodiment, the road section itself in which the high-precision map includes information representing the reference driving trajectory of each lane may be the predetermined section.

[0062] FIG. 6 is a functional block diagram of the processor 23 related to the vehicle control process according to the second embodiment. The processor 23 includes a host lane detection unit 31, a selection unit 34, and a vehicle control unit 33. Each of these units included in the processor 23 is, for example, a functional module realized by a computer program operating on the processor 23. Alternatively, each of these units included in the processor 23 may be a dedicated arithmetic circuit provided in the processor 23.

[0063] The host lane detection unit 31 detects the host lane in which the vehicle 10 is traveling, in the same manner as in the first embodiment. Then, the host lane detection unit 31 notifies the detected host lane to the selection unit 34.

[0064] The selection unit 34 refers to the high-precision map and identifies a predetermined section existing between the current position of the vehicle 10 and a point a predetermined distance ahead along the traveling direction of the vehicle 10. Then, the selection unit 34 sets a target traveling trajectory based on the reference traveling trajectories of each lane in the predetermined section. In the present embodiment, when the vehicle 10 travels in the predetermined section, the selection unit 34 selects, as the target lane, the lane in which the reference traveling trajectory with the highest safety is shown among the reference traveling trajectories of each lane in the traveling direction of the vehicle 10. At this time, like the above-described modification example, the selection unit 34 may use, as the lanes to be selected, the lanes in which the vehicle 10 can move until the vehicle 10 reaches the predetermined section. Alternatively, when the predetermined section includes an intersection or a branch point, the selection unit 34 may use, as the lanes to be selected, the lanes among the plurality of lanes in the predetermined section that enable the vehicle 10 to reach the destination of the vehicle 10, with reference to the planned traveling route of the vehicle 10 received from a navigation device (not shown).

[0065] For example, the selection unit 34 determines that the lane with a smaller deviation amount from the center of the lane to the reference traveling trajectory for each lane to be selected is safer. Alternatively, the selection unit 34 may determine that the lane with a smaller maximum value of the angular change in the traveling direction per unit distance in the reference traveling trajectory is safer.

[0066] Also, when a predetermined section includes an intersection, for the reference driving trajectory at that intersection, the relative position of the lane with respect to the road edge may be different when entering the intersection and when exiting the intersection. For example, when entering an intersection with a lane number of three or more lanes on one side, the reference driving trajectory of the second lane from the center side may move to the leftmost lane when turning right at the intersection and exiting the intersection. In such a case, there is a possibility that a vehicle turning right at the intersection along the reference driving trajectory of the second lane from the center side and another vehicle entering the intersection from the oncoming lane and turning left at the intersection may travel in the same lane when exiting the intersection. On the other hand, if the reference driving trajectory for the lane on the very center side maintains the rightmost lane even after a right turn, it is assumed that the possibility of the above situation occurring is low. Also, if there are multiple lanes where left turns are possible at an intersection, and for the reference driving trajectory of any one of those lanes, it moves to the right lane when exiting the intersection, it is assumed that when vehicle 10 travels along that lane, it will be necessary to move to the right lane after a left turn. In contrast, if the reference driving trajectory of the rightmost lane among those lanes where left turns are possible maintains the rightmost lane even after exiting the intersection, it is assumed that vehicle 10 does not need to change lanes after a left turn when traveling along that rightmost lane. Therefore, the selection unit 34 determines that the safety of the reference driving trajectory where the position of the lane including the entry point of the predetermined section is the same as the position of the lane including the exit point of the predetermined section is higher than the safety of the reference driving trajectory where the position of the lane including the entry point of the predetermined section and the position of the lane including the exit point of the predetermined section are different. As a result, since the lane indicated by the reference driving trajectory that maintains the lane is prioritized, the selection unit 34 can select the target lane so as to suppress the implementation of inadvertent lane changes.

[0067] The selection unit 34 may select a target lane according to any one or more of the above-described selection criteria for each lane. When a plurality of selection criteria are used, the selection unit 34 preferentially selects, for example, the lane in which the reference travel trajectory maintained in the lane is shown during a predetermined section. When there are a plurality of such lanes, the selection unit 34 evaluates, for the plurality of lanes, either the deviation amount of the reference travel trajectory from the center of the lane or the maximum value of the angular change in the traveling direction per unit distance as the second criterion and the other as the third criterion to select the target lane. Alternatively, when there are a plurality of lanes prioritized according to any of the above selection criteria, the selection unit 34 may select, as the target lane, the lane closest to the own lane among the plurality of lanes.

[0068] The selection unit 34 sets the reference travel trajectory of the target lane determined to be the safest for a predetermined section as the target travel trajectory. Further, when the target lane is different from the own lane, the selection unit 34 sets the target travel trajectory for the section from the current position of the vehicle 10 until reaching the predetermined section so that the vehicle 10 moves from the own lane to the target lane until reaching the predetermined section.

[0069] FIG. 7 is a diagram showing an example of safety among the reference travel trajectories of each lane. In the example shown in FIG. 7, the predetermined section includes an intersection 700. Among the plurality of lanes included in a road 710 which is one of the roads entering the intersection 700, left turns are possible at the intersection 700 for two lanes 711 and 712. Further, on a road 720 located on the left side as viewed from the road 710, three lanes 721, 722, and 723 for exiting from the intersection 700 are provided.

[0070] Here, in the reference driving trajectory 711a for making a left turn from the leftmost lane 711 on road 710, it is shown that even when exiting intersection 700, it passes through the leftmost lane 721. That is, in the reference driving trajectory 711a, when entering and exiting a predetermined section, the position of the lane relative to the road edge does not change. In contrast, in the reference driving trajectory 712a for making a left turn from the second leftmost lane 712 on road 710, it is shown that when exiting intersection 700, it passes through the centermost lane 723 on road 720. That is, in the reference driving trajectory 712a, when entering and exiting a predetermined section, the relative position of the lane with respect to the road edge changes. Therefore, it is determined that the reference driving trajectory 711a for lane 711 is safer than the reference driving trajectory 712a for lane 712. Therefore, when vehicle 10 enters intersection 700 from road 710 and makes a left turn at intersection 700, lane 711 is selected as the target lane.

[0071] When the selection unit 34 sets a target driving trajectory until passing through a predetermined section from the current position of vehicle 10, it notifies the set target driving trajectory to the vehicle control unit 33.

[0072] The vehicle control unit 33 controls each part of vehicle 10 so that vehicle 10 travels along the target driving trajectory, in the same manner as the vehicle control unit 33 according to the first embodiment. Note that when the target lane and the own lane are different, the vehicle control unit 33 controls each part of vehicle 10 so that vehicle 10 moves from the own lane to the target lane along the target driving trajectory before reaching a predetermined section.

[0073] FIG. 8 is an operation flowchart of vehicle control processing according to the second embodiment. The processor 23 may execute vehicle control processing according to the following operation flowchart at a predetermined cycle.

[0074] The own lane detection unit 31 of the processor 23 detects the own lane in which vehicle 10 is traveling (step S201).

[0075] Also, the selection unit 34 of the processor 23 selects, as the target lane, the lane in which the safest reference driving trajectory among the reference driving trajectories of each lane in a predetermined section of the destination of the vehicle 10 is shown (step S202). Then, the selection unit 34 sets a target driving trajectory so that the vehicle 10 moves from the own lane to the target lane in the section until reaching the predetermined section from the current position of the vehicle 10 (step S203). Further, the selection unit 34 sets the reference driving trajectory of the target lane as the target driving trajectory for the predetermined section (step S204).

[0076] The vehicle control unit 33 of the processor 23 controls each part of the vehicle 10 so that the vehicle 10 travels along the target driving trajectory (step S205). Then, the processor 23 ends the vehicle control process.

[0077] As described above, the vehicle control device according to the second embodiment selects, as the target lane, the lane in which the safest reference driving trajectory is shown by referring to the reference driving trajectories for each lane for a predetermined section of the destination of the vehicle. And this vehicle control device makes the vehicle travel along the reference driving trajectory of the selected lane. Therefore, this vehicle control device can guide the host vehicle to a safer lane.

[0078] According to a modification, the vehicle control unit 33 may execute follow-up control for controlling the vehicle 10 to travel following a preceding vehicle traveling ahead of the vehicle 10. In this case, when the predetermined section is a section including an intersection and, after a right turn or a left turn at the intersection, the reference driving trajectory of the own lane is a trajectory that moves to an adjacent lane, the preceding vehicle is likely to move to the adjacent lane after a right turn or a left turn at the intersection. Therefore, in such a predetermined section including an intersection, when follow-up control is applied to the vehicle 10, the vehicle control unit 33 may lower the priority of the follow-up control. The vehicle control unit 33 may, for example, control each part of the vehicle 10 so that the vehicle 10 does not follow the preceding vehicle and maintains traveling in the own lane even if the preceding vehicle moves to an adjacent lane.

[0079] Further, the processor 23 may be configured to be capable of executing both the vehicle control according to the first embodiment and the vehicle control according to the second embodiment. For example, the processor 23 may select a target lane in a predetermined section and set a target travel trajectory from the current position of the vehicle 10 to the predetermined section by executing the vehicle control process according to the second embodiment. Then, the processor 23 may set a target travel trajectory in a predetermined section by executing the vehicle control process according to the first embodiment for the predetermined section.

[0080] A computer program for realizing the functions of the processor 23 of the ECU 5 according to the above embodiment or modification example may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium.

[0081] As described above, those skilled in the art can make various changes according to the implemented forms within the scope of the present invention.

Explanation of Reference Numerals

[0082] 1 Vehicle control system 10 Vehicle 2 Camera 3 GPS receiver 4 Storage device 5 Electronic control unit (ECU) 21 Communication interface 22 Memory 23 Processor 31 Own-lane detection unit 32 Trajectory setting unit 33 Vehicle control unit 34 Selection unit

Claims

1. A storage unit that stores driving trajectory distribution information representing the distribution of driving trajectories for each lane in a predetermined section of a road; A trajectory setting unit that sets a target driving trajectory of the vehicle by referring to the driving trajectory distribution information for other lanes different from the lane in which the vehicle is driving when the vehicle drives through the predetermined section; A vehicle control unit that drives the vehicle along the target driving trajectory; comprising: The driving trajectory distribution information includes a plurality of driving trajectories for each lane in the predetermined section; The trajectory setting unit sets the target driving trajectory so as to be separated from any of the plurality of driving trajectories included in the driving trajectory distribution information for the other lanes by a predetermined interval or more; A vehicle control device.

2. A storage unit that stores driving trajectory distribution information representing the distribution of driving trajectories for each lane in a predetermined section of a road; A trajectory setting unit that sets a target driving trajectory of the vehicle by referring to the driving trajectory distribution information for other lanes different from the lane in which the vehicle is driving when the vehicle drives through the predetermined section; A vehicle control unit that drives the vehicle along the target driving trajectory; comprising: The driving trajectory distribution information includes a reference driving trajectory and a variation index value representing the degree of variation of the driving trajectory; The trajectory setting unit sets the target driving trajectory so as to be separated from the reference driving trajectory of the other lane as the variation index value included in the driving trajectory distribution information for the other lane becomes larger. A vehicle control device.

3. The trajectory setting unit refers to the driving trajectory distribution information, identifies the lane in which the variation index value is minimized in the predetermined section, and moves the vehicle to the identified lane until the vehicle reaches the predetermined section. The vehicle control device according to claim 2, wherein a target driving trajectory from the current position of the vehicle to the predetermined section is set.

4. When a vehicle drives through a predetermined section of a road, referring to the driving trajectory distribution information for other lanes different from the lane in which the vehicle is driving among the driving trajectory distribution information representing the distribution of driving trajectories for each lane in the predetermined section, setting a target driving trajectory of the vehicle; Driving the vehicle along the target driving trajectory; including: The driving trajectory distribution information includes a plurality of driving trajectories for each lane in the predetermined section; Setting the target driving trajectory of the vehicle includes setting the target driving trajectory so as to be separated from any of the plurality of driving trajectories included in the driving trajectory distribution information for the other lane by a predetermined interval or more. Vehicle control method.

5. When the vehicle travels through a predetermined section of a road, referring to the driving trajectory distribution information for other lanes different from the own lane in which the vehicle travels among the driving trajectory distribution information representing the distribution of driving trajectories for each lane in the predetermined section, setting the target driving trajectory of the vehicle, and driving the vehicle along the target driving trajectory. This includes wherein the driving trajectory distribution information includes a reference driving trajectory and a variation index value representing the degree of variation of the driving trajectory. Setting the target driving trajectory of the vehicle includes setting the target driving trajectory so as to be separated from the reference driving trajectory of the other lane as the variation index value included in the driving trajectory distribution information for the other lane increases. Vehicle control method.

6. When the vehicle travels through a predetermined section of a road, referring to the driving trajectory distribution information for other lanes different from the own lane in which the vehicle travels among the driving trajectory distribution information representing the distribution of driving trajectories for each lane in the predetermined section, setting the target driving trajectory of the vehicle, and driving the vehicle along the target driving trajectory. This is caused to be executed by a processor mounted on the vehicle. The driving trajectory distribution information includes a plurality of driving trajectories for each lane in the predetermined section. Setting the target driving trajectory of the vehicle includes setting the target driving trajectory so as to be separated from any of the plurality of driving trajectories included in the driving trajectory distribution information for the other lane by a predetermined interval or more. Vehicle control computer program.

7. When the vehicle travels through a predetermined section of a road, referring to the driving trajectory distribution information for other lanes different from the own lane in which the vehicle travels among the driving trajectory distribution information representing the distribution of driving trajectories for each lane in the predetermined section, setting the target driving trajectory of the vehicle, and driving the vehicle along the target driving trajectory. This is caused to be executed by a processor mounted on the vehicle. The driving trajectory distribution information includes a reference driving trajectory and a variation index value representing the degree of variation of the driving trajectory. Setting the target travel trajectory of the vehicle includes setting the target travel trajectory to be farther from the reference travel trajectory of the other lane as the variation index value included in the travel trajectory distribution information for the other lane becomes larger. A computer program for vehicle control.

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