Vehicle control system

Abstract

To provide a vehicle control device that enables robust vehicle control capable of addressing risks that could not be foreseen during track planning when operating a vehicle autonomously. [Solution] The control device for the vehicle 1 of the present invention comprises: a trajectory plan determination unit 11 that determines which trajectory plan to adopt as the future travel trajectory of the vehicle 1 is a target path maintenance trajectory, a left avoidance trajectory, or a right avoidance trajectory; a motion plan determination unit 12 that determines which motion plan to adopt as the future motion mode of the vehicle 1 is a normal motion in accordance with the trajectory plan or an emergency evasive motion that temporarily disables the trajectory plan; and a vehicle control unit 13 that controls the vehicle 1 so that the running state of the vehicle 1 at each point in time conforms to the motion plan. The trajectory plan determination unit 11 and the motion plan determination unit 12 update the trajectory plan and the motion plan sequentially, respectively, and the update frequency of the motion plan determination unit 12 is higher than the update frequency of the trajectory plan determination unit 11.

Description

Technical Field

[0001] The present disclosure relates to a control device for a vehicle.

Background Art

[0002] In recent years, the development of ADAS (Advanced Driver Assistance Systems) and autonomous driving related technologies in automobiles has been advancing rapidly. For example, as functions for automating part of driving operations, Adaptive Cruise Control, Lane Keep Assist System, Emergency Automatic Braking, etc. have reached practical use.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

[0005]

Non-Patent Document 2

[0006] [Non-Patent Document 3] D. Fox, et al. "The dynamic window approach to collision avoidance", IEEE Robotics & Automation Magazine, Volume 4, Issue 1, Page 23 - 33, Published: 06 August 2002 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, in this type of autonomous driving technology, a control system has been developed that acquires information about objects around the vehicle, generates a trajectory plan for the vehicle based on the acquired object information and map information, and then drives the vehicle automatically to follow that plan (see, for example, Patent Document 1).

[0008] However, in conventional vehicle control devices such as those described in Patent Document 1, the calculation time required to generate the track plan is long, which can make it difficult to avoid danger when risks that could not be anticipated during track planning occur. In addition, the computational load for track planning and track following control is high, which can make it difficult to update the vehicle motion instruction values ​​at the high frequency required for automated driving.

[0009] This invention has been made in view of the above-mentioned problems, and aims to provide a vehicle control device that can achieve robust vehicle control capable of dealing with risks that could not be foreseen during track planning. [Means for solving the problem]

[0010] The main present invention that solves the aforementioned problems is: A control device for a vehicle that automatically travels along a predetermined target path, A track planning determination unit determines, based on the surrounding information of the vehicle, which track plan to adopt as the future travel trajectory of the vehicle is a target path maintenance track, a left avoidance track, or a right avoidance track. A motion plan determination unit determines, based on the surrounding object information, which motion plan to adopt as the future motion mode of the vehicle is either normal motion in accordance with the trajectory plan or emergency evasive motion that temporarily disables the trajectory plan. A vehicle control unit controls the vehicle so that the vehicle's driving state at each point in time conforms to the motion plan, based on the motion plan and information relating to the vehicle's driving state. Equipped with, The trajectory planning unit and the motion planning unit update the trajectory plan and motion plan sequentially, respectively, and the update frequency of the motion planning unit is higher than that of the trajectory planning unit. It is a control device. [Effects of the Invention]

[0011] The vehicle control device according to the present invention enables robust vehicle control that can address risks that could not be anticipated during track planning. In addition, it reduces the computational load on the control system when the vehicle is autonomously driven, and enables vehicle motion control to be performed at a high frequency. [Brief explanation of the drawing]

[0012] [Figure 1] Diagram showing the vehicle configuration [Figure 2] Block diagram showing the functional configuration of the control unit. [Figure 3] This diagram shows an example of how a vehicle moves automatically along a predetermined target route set as a driving schedule. [Figure 4]A diagram for explaining the trajectory plan (Fig. 4A) determined by the trajectory plan determination unit and the motion plan (Fig. 4B) determined by the motion plan determination unit [Figure 5] A flowchart showing an example of the operation content of the trajectory plan determination unit [Figure 6] A flowchart showing an example of the operation content of the motion plan determination unit

Embodiments for Carrying out the Invention

[0013] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same function are denoted by the same reference numerals, and redundant description is omitted.

[0014] [Configuration of the Vehicle] First, an example of the configuration of a vehicle (hereinafter referred to as "vehicle 1") according to an embodiment of the present invention will be described. The vehicle 1 according to the present embodiment is a vehicle equipped with a control device capable of executing autonomous driving.

[0015] Fig. 1 is a diagram showing the configuration of vehicle 1.

[0016] Vehicle 1 is equipped with, for example, a vehicle drive device 20, a traveling state detection device 30, a position information acquisition device 40, a surrounding information acquisition device 50, an HMI (Human Machine Interface) 60, a storage device 70, and a control device 10.

[0017] The vehicle drive device 20 is a drive unit that causes vehicle 1 to travel, and includes, for example, a drive motor, a power transmission mechanism, a brake device, a steering device, and the like. The vehicle drive device 20 generates power with, for example, a drive motor, and transmits the power to the wheels via a power transmission mechanism (propeller shaft, differential gear, drive shaft, etc.) to cause vehicle 1 to travel. The operation of the vehicle drive device 20 is controlled by the control device 10.

[0018] The driving state detection device 30 is a set of sensors that detect the driving state of the vehicle 1. For example, the driving state detection device 30 includes an accelerator opening sensor that detects the accelerator opening, a steering angle sensor that detects the steering angle of the steering device, an acceleration sensor that detects the acceleration acting on the vehicle 1 in the longitudinal direction, a torque sensor that detects the torque acting on the power transmission mechanism between the wheels and the engine of the vehicle 1, and a vehicle speed sensor that detects the vehicle speed of the vehicle 1.

[0019] The location information acquisition device 40 detects the current location of the vehicle 1. The location information acquisition device 40 has, for example, a GPS antenna that periodically receives GPS signals from multiple GPS satellites, determines the current location of the vehicle 1 from the GPS signals, and transmits the location information of the vehicle 1 to the control device 10.

[0020] Furthermore, the position information acquisition device 40 may detect the current position of the vehicle 1 as its relative position to objects around the vehicle 1. In that case, the position information acquisition device 40 may be composed of an on-board camera, an infrared sensor, sonar, or radar, etc.

[0021] The surrounding information acquisition device 50 is a sensor that detects the position of objects present around the vehicle 1, and is composed of, for example, an on-board camera, an infrared sensor, sonar, or radar. The surrounding information acquisition device 50 is, for example, installed at each of the four corners of the vehicle 1 so that it can detect objects in each direction around the vehicle 1. The surrounding information acquisition device 50 outputs the information on objects around the vehicle 1 that it has detected to the control device 10.

[0022] Furthermore, the surrounding information acquisition device 50 more preferably uses both radar and an on-board camera. The on-board camera can be suitably used to determine the two-dimensional position of surrounding objects. Radar can be suitably used to accurately detect the distance to surrounding objects.

[0023] The surrounding object information acquired by the surrounding information acquisition device 50 includes, for example, attribute information of pedestrians, bicycles, vehicles, etc., as well as their current position and current velocity vectors.

[0024] HMI60 is a user interface that accepts input operations from a user (hereinafter referred to as "user") riding in vehicle 1, such as a touch panel or keyboard. HMI60 is configured to accept input operations such as execution commands when performing autonomous driving.

[0025] The storage device 70 is, for example, an auxiliary storage device such as an HDD, SSD, or USB memory. The storage device 70 stores, for example, a control program 70e for automatically driving the vehicle 1, as well as data such as map information 70a, driving schedule information 70b, track model 70c, and motion model 70d.

[0026] Map information 70a is a database relating to map data that stores, for example, road maps and the coordinates of said road maps in association. The road maps in map information 70a consist of road information such as the location of intersections, the location of traffic lights, and the number of lanes. The coordinates of the road maps are set based on, for example, latitude and longitude or a predetermined location (for example, an intersection around vehicle 1).

[0027] Furthermore, map information 70a is referenced, for example, to identify a target route when automatically driving vehicle 1, or to identify a reference route when changing lanes from the current driving lane.

[0028] The driving schedule information 70b is, for example, information relating to the target route from the starting point to the target destination set when starting the vehicle 1 to drive. The target route in the driving schedule information 70b is stored in association with the road map in the map information 70a, for example, and defines the target position on the road map that vehicle 1 should travel to at each point during driving. In addition, if the driving route has multiple lanes, the system also sets which lane to use. Furthermore, the target route in the driving schedule information 70b is stored in association with the target speed under normal conditions (hereinafter referred to as the "scheduled speed"), for example, the legal speed limit under road regulations.

[0029] Furthermore, the driving schedule information 70b is generated, for example, by the driving schedule generation function of the control device 10 based on the driving start point and driving target point input by the user. Since the driving schedule generation function is a well-known technology, its explanation is omitted here. However, the driving schedule information 70b may also be obtained by acquiring a driving schedule generated by an external device (not shown) via a communication circuit or the like.

[0030] The track model 70c is model data used to generate the track plan for vehicle 1, which is referenced by the track plan determination unit 11 of the control device 10, described later. For example, the track model 70c stores track models related to the target path maintenance track, the left avoidance track, and the right avoidance track (see Figure 4).

[0031] The motion model 70d is model data used to generate the motion plan of the vehicle 1, which is referenced by the motion plan determination unit 12 of the control device 10, described later. The motion model 70d stores, for example, motion models related to normal motion along the trajectory plan or emergency evasive maneuvers that temporarily disable the trajectory plan (in this case, emergency stop maneuvers or emergency steering avoidance maneuvers) (see Figure 4).

[0032] Furthermore, some or all of the data stored in the storage device 70 may also be stored in the ROM 10b or the like of the control device 10.

[0033] The control device 10 is an electronic control unit that provides comprehensive control over all parts of the vehicle 1. The control device 10 controls each part of the vehicle drive system 20 (for example, the output of the drive motor, the engagement and disengagement of the clutch, the gear of the automatic transmission, and the steering angle of the steering system) so that the driving state of the vehicle 1 is optimized, while referring to sensor information from the driving state detection device 30. The control device 10 is configured to control the vehicle drive system 20 so that the vehicle 1 can perform automatic driving (meaning autonomous driving; the same applies hereinafter).

[0034] The control device 10 is composed of, for example, a CPU 10a, a ROM 10b, a RAM 10c, an input port (not shown), and an output port (not shown). The control device 10's CPU 10a reads a program corresponding to the processing content from the ROM 10b and the storage device 70, expands it into the RAM 10b, and centrally controls the operation of each block in cooperation with the expanded program. At this time, various data stored in the storage device 70 are referenced.

[0035] Furthermore, the control device 10 is interconnected with the vehicle drive unit 20, the driving state detection unit 30, the position information acquisition unit 40, the surrounding information acquisition unit 50, the HMI 60, and the storage device 70 via an in-vehicle network (for example, a communication network compliant with the CAN communication protocol), enabling the mutual transmission and reception of necessary data and control signals.

[0036] [Configuration of the vehicle's control system] Next, the configuration of the control device 10 according to this embodiment will be described. Here, only the configuration of the control device 10 according to this embodiment that causes the vehicle 1 to automatically travel along a predetermined target route set as a travel schedule, while avoiding surrounding objects present at each point, will be described.

[0037] Figure 2 is a block diagram showing the functional configuration of the control device 10. The arrows in Figure 2 represent the signal transmission paths.

[0038] Figure 3 shows an example of the movement pattern of vehicle 1 as it automatically travels along a predetermined target route set as a travel schedule.

[0039] Figure 4 illustrates the trajectory plan determined by the trajectory planning unit 11 (Figure 4A) and the motion plan determined by the motion planning unit 12 (Figure 4B).

[0040] The control device 10 has the functions of a track plan determination unit 11, a motion plan determination unit 12, and a vehicle control unit 13 in order to automatically drive the vehicle 1.

[0041] As described above, the vehicle 1 according to this embodiment is configured to automatically travel along a predetermined target route set as a travel schedule under the control of the control device 10. However, while the vehicle 1 is actually traveling, various obstacles exist on the travel route, as shown in Figure 3, so the control device 10 needs to make the vehicle 1 travel while avoiding such obstacles. Examples of such obstacles include pedestrians, other vehicles, and fallen objects on the travel route.

[0042] In Figure 3, LL represents the road on which Vehicle 1 is traveling (e.g., a two-lane road), L1 represents the target route, L2 represents other traversable routes on the road adjacent to the target route (e.g., lanes different from the target route L1), and B1 represents obstacles present on the target route (e.g., other vehicles stopped on the road).

[0043] The trajectory planning unit 11 is a function that, based on information about objects surrounding the vehicle 1, causes the vehicle 1 to travel stably along a target path while avoiding such obstacles. In other words, under the circumstances shown in Figure 4A, the trajectory planning unit 11 generates a trajectory plan that avoids such obstacles.

[0044] Furthermore, Figure 4A shows an embodiment in which a trajectory plan (i.e., a rightward avoidance trajectory) is generated in which vehicle 1 changes lanes from the target trajectory L1 to another trajectory L2 adjacent to the right side of the target trajectory (for example, a different lane from the lane of the target trajectory L1) in order to avoid an obstacle B1 detected in front of the travel path (i.e., the target trajectory L1).

[0045] Here, the track planning unit 11 receives sequentially detected driving status information of the vehicle 1 (representing information from the driving status detection device 30), the current location information of the vehicle 1 (representing information from the location information acquisition device 40), and information on objects surrounding the vehicle 1 (representing information from the surrounding information acquisition device 50). Based on this information, along with information related to the driving schedule (here, the target route and scheduled vehicle speed) 70b, map information 70a, and track models 70c for each configuration, the track planning unit 11 generates a track plan (hereinafter abbreviated as "track plan") as the driving path of the vehicle 1 from one time point in the future to a predetermined period in the future.

[0046] Furthermore, the "track plan" is, for example, time-series data relating to the target driving position and target vehicle speed of vehicle 1 at each point in time from one time point ahead to a predetermined period ahead (for example, 10 seconds ahead) (for example, 100 time-series points of target driving position and target vehicle speed at 0.1-second intervals from one time point ahead). In this embodiment, since the track plan set by the track plan determination unit 11 is not directly used as an instruction value for vehicle motion control, it is desirable to generate the track plan based on a future prediction of the vehicle position using a kinematic model, which has a low computational load among vehicle motion models, in order to reduce the computational load.

[0047] Specifically, the trajectory planning unit 11 first determines which trajectory plan to adopt—a target path maintenance trajectory, a left avoidance trajectory, or a right avoidance trajectory—using a predetermined cost function based on surrounding object information for the vehicle 1. For example, if no obstacles are detected around the vehicle 1 (e.g., in front) in the surrounding object information, the trajectory planning unit 11 selects the target path maintenance trajectory. On the other hand, if obstacles are detected around the vehicle 1 (e.g., in front) in the surrounding object information, the trajectory planning unit 11 selects either a left avoidance trajectory or a right avoidance trajectory as the trajectory plan. In this case, whether to adopt a left avoidance trajectory or a right avoidance trajectory depends on the traversable path adjacent to the target path.

[0048] Here, "target path maintenance trajectory" refers to a trajectory that travels along the target path, "left avoidance trajectory" refers to a trajectory that changes lanes to a path shifted to the left of the target path, and "right avoidance trajectory" refers to a trajectory that changes lanes to a path shifted to the right of the target path. These trajectory models 70c are stored in the memory device 70 in advance, and the trajectory planning unit 11 generates a trajectory plan based on these trajectory models 70c.

[0049] For example, in the case of a "target path maintenance track," the track plan determination unit 11 generates a track plan based on the track model 70c for the "target path maintenance track" so that the vehicle travels along the target path set as the travel schedule at the scheduled speed (e.g., legal speed).

[0050] On the other hand, for a "left avoidance trajectory" or a "right avoidance trajectory," the trajectory planning unit 11 refers to a drivable path adjacent to the target path and calculates a trajectory profile according to the trajectory model 70c for the "left avoidance trajectory" or "right avoidance trajectory" so that the movement trajectory from the vehicle 1's current position to the drivable path is appropriate. The trajectory profile set on the trajectory model 70c is not particularly limited, but for example, it may be a trajectory that draws a spline curve from the current position to the target position. For example, if the "left avoidance trajectory" or "right avoidance trajectory" is a lane change from the vehicle 1's current position, this movement trajectory will be a spline curve that smoothly connects from the current position to the centerline of the lane to which the vehicle will change. In this case, the target vehicle speed may be set to a value different from the scheduled vehicle speed so that the lane change can be performed smoothly.

[0051] Furthermore, the trajectory planning unit 11 may use, for example, the known Frenet Frame method (see Non-Patent Document 1) or the known Attractor Dynamic Approach method (see Non-Patent Document 2) as a method for calculating the trajectory profile of the trajectory plan.

[0052] Furthermore, drivable routes adjacent to the target route can be identified, for example, from map information 70a. For example, as shown in Figure 4A, the road on which vehicle 1 travels can be identified as having two lanes on the map information 70a, and if the target route is set to one lane (e.g., left lane L1), the other lane (e.g., right lane L2) is identified as a drivable route. In this case, the road information (map information 70a) of vehicle 1's current location can be obtained by map matching with vehicle 1's current location.

[0053] On the other hand, if the route that vehicle 1 will travel is not defined on the map information 70a, the traversable route can also be identified by the surrounding conditions information from the surrounding conditions information acquisition device 50. Furthermore, in off-road environments (where the traversable route is not defined on the map information 70a and cannot be identified by the surrounding conditions information from the surrounding conditions information acquisition device 50), it is also possible to plan a new traversable route from the current vehicle position to the target destination without colliding with obstacles, and to set this route as the target route. Such route planning may be carried out even less frequently than the update frequency of the track plan.

[0054] The trajectory planning unit 11 updates the trajectory plan sequentially. The frequency of trajectory plan updates in the trajectory planning unit 11 depends on the performance of the CPU 10a that constitutes the control device 10, but it is desirable to have a frequency of 5 Hz or higher, for example.

[0055] Furthermore, while vehicle 1 has passed the obstacle, the trajectory planning unit 11 maintains and updates the trajectory plan related to the "left avoidance trajectory" or "right avoidance trajectory". Then, when the trajectory planning unit 11 detects that vehicle 1 has passed the obstacle based on the surrounding object information, it selects the "target path maintenance trajectory" as the trajectory plan. When returning vehicle 1 from the position where it changed lanes to the target path, the trajectory planning unit 11 may return it to the target path through feedback control in the vehicle control unit 13 (motion planning unit 12), but even in this case, it is desirable for the trajectory planning unit 11 to generate a trajectory plan such that the movement trajectory of vehicle 1 from the position where it changed lanes to the target path is a spline curve. In this case, for example, a trajectory model 70c for the "return trajectory" is prepared, and the trajectory planning unit 11 is set to select the "return trajectory" after the "left avoidance trajectory" or "right avoidance trajectory".

[0056] As described above, the functions of the track planning unit 11 make it possible to stably drive the vehicle 1 along the target path while avoiding obstacles. However, while the vehicle 1 is actually running, there may be obstacles B2 that suddenly approach the vehicle 1, as shown in Figure 4B. In such cases, the calculation time for generating the track plan is long, and it may become difficult to avoid danger when risks that could not be anticipated during track planning occur.

[0057] The motion plan determination unit 12 has the function of temporarily invalidating the trajectory plan generated by the trajectory plan determination unit 11 when an obstacle suddenly approaches the vehicle 1, causing the vehicle 1 to take an emergency evasive maneuver. In other words, the motion plan determination unit 12 generates a motion plan that avoids a collision with such an obstacle, and makes it possible to drive the vehicle 1 along that motion plan. Figure 4B shows an example in which a motion plan is generated to bring the vehicle 1, which is traveling along a trajectory plan that avoids obstacle B2 rapidly approaching the vehicle 1, to an emergency stop.

[0058] Here, the motion plan determination unit 12 receives sequentially detected driving state information of the vehicle 1 (information from the driving state detection device 30), the current position information of the vehicle 1 (information from the position information acquisition device 40), and information on objects surrounding the vehicle 1 (information from the surrounding information acquisition device 50), as well as trajectory plan information from the trajectory plan determination unit 11. Based on this information and the motion model 70d, the motion plan determination unit 12 generates a motion plan (hereinafter abbreviated as "motion plan") representing the motion of the vehicle 1 from one time point in the future to a predetermined period in the future.

[0059] Furthermore, the "motion plan" is, for example, time-series data relating to the target acceleration / deceleration and target yaw rate of vehicle 1 at each point in time from one time point ahead to a predetermined period ahead (for example, one second ahead) (for example, time-series points of target acceleration / deceleration and target yaw rate at 0.1-second intervals from one time point ahead). Furthermore, since the motion plan set by the motion plan determination unit 12 is directly adopted as the instruction value for vehicle motion control, it is desirable to generate the motion plan based on a future prediction of the vehicle position using a dynamics model, which is a more detailed vehicle motion model than the kinematics model.

[0060] Specifically, first, the motion plan determination unit 12 uses a predetermined cost function based on information about objects surrounding the vehicle 1 to determine whether to adopt a normal motion in line with the trajectory plan, or an emergency stop motion or emergency steering avoidance motion that temporarily disables the trajectory plan.

[0061] "Normal motion" refers to motion in accordance with the track plan, while "emergency stop motion or emergency steering avoidance motion" refers to temporarily disabling the track plan and adopting a pre-set emergency evasive maneuver. "Emergency stop motion" is a motion to reduce the target acceleration / deceleration on the current track and bring vehicle 1 to a stop. On the other hand, "emergency steering avoidance motion" is a motion to move vehicle 1 to the opposite side from the approaching obstacle B2 when an emergency stop on the current track would result in a collision with an obstacle B2 rapidly approaching vehicle 1.

[0062] In other words, the motion plan determination unit 12 selects "normal motion" when no obstacles rapidly approaching the vehicle 1 are detected in the surrounding object information. In this case, the motion plan determination unit 12 calculates the motion profile of the motion plan (i.e., the target acceleration / deceleration and target yaw rate at each point in time) based on the vehicle 1's driving state information and the vehicle 1's current position information, in order to satisfy the target driving position and target vehicle speed of the vehicle 1 at each point in time set in the trajectory plan.

[0063] On the other hand, if the motion plan determination unit 12 detects an obstacle rapidly approaching the vehicle 1 in the surrounding object information, it switches from "normal motion" to "emergency stop motion" or "emergency steering avoidance motion". If the motion plan determination unit 12 selects "emergency stop motion" as the motion plan, it sets the motion profile for the emergency stop motion based on the motion model 70d for "emergency stop motion". In emergency stop motion, for example, a motion profile is set that determines the degree of deceleration until the vehicle 1 is brought to a sudden stop without applying excessive G-forces to the occupants, based on the current vehicle speed. Also, if the motion plan determination unit 12 selects "emergency steering avoidance motion" as the motion plan, it sets the motion profile for emergency steering avoidance motion based on the motion model 70d for "emergency steering avoidance motion". In emergency steering avoidance motion, for example, a motion profile is set that determines the degree of deceleration while avoiding the obstacle by drawing a spline curve to the left or right, based on the current vehicle speed, without applying excessive G-forces to the occupants. Furthermore, since emergency steering avoidance is a fairly high-risk evasive maneuver, it is desirable that the motion plan determination unit 12 first consider whether avoidance is possible by braking (emergency stop), and only implement emergency steering avoidance as a last resort.

[0064] Furthermore, the exercise planning unit 12 may use, for example, a known dynamic window approach method (see Non-Patent Literature 3) as a method for calculating the exercise profile of the exercise plan.

[0065] The motion plan determination unit 12 determines whether to select "emergency stop motion" or "emergency steering avoidance motion" as the motion plan, based on the distance between the vehicle 1 and the rapidly approaching obstacle, the predicted trajectories of both, or information on possible routes around the vehicle 1.

[0066] Here, the motion plan determination unit 12 updates the motion plan sequentially. The update frequency of the motion plan in the motion plan determination unit 12 depends on the performance of the CPU 10a that constitutes the control device 10, but it is desirable to have a frequency of 10 Hz or higher. However, the update frequency of the motion plan determination unit 12 is set to be at least higher than the update frequency of the track plan determination unit 11. This makes it possible to avoid danger even when an obstacle rapidly approaches the vehicle 1 (i.e., a risk that could not be anticipated during track planning) appears.

[0067] The vehicle control unit 13 acquires the motion plan generated by the motion plan determination unit 12 and the vehicle's driving state information output from the driving state detection device 30. The vehicle control unit 13 then provides feedback control to the vehicle drive unit 20 so that the vehicle's driving state at each point in time conforms to the motion plan.

[0068] Figure 5 is a flowchart showing an example of the operation of the trajectory planning unit 11.

[0069] In step S1, the trajectory planning unit 11 first determines, based on surrounding object information, whether or not there is an obstacle ahead on the target path. If an obstacle is found ahead (step S1: YES), the trajectory planning unit 11 proceeds to step S3. On the other hand, if no obstacle is found ahead (step S1: NO), the trajectory planning unit 11 selects the target path maintenance trajectory as the trajectory plan (step S2). In this target path maintenance trajectory, for example, the trajectory profile of the trajectory plan is set so that vehicle 1 travels along the target path at the scheduled speed.

[0070] In step S3, the trajectory planning unit 11 determines whether steering avoidance is necessary for the obstacle detected in step S1 when the vehicle 1 travels along the target path. If steering avoidance is not necessary (step S3: NO), the trajectory planning unit 11 selects a target path maintenance trajectory as the trajectory plan (step S4). Here, if the speed of the obstacle detected in step S1 is sufficiently fast, the trajectory planning unit 11 does not take unnecessary avoidance action and maintains the target path maintenance trajectory. Also, the trajectory planning unit 11 refers to the map information 70A and, if lane changes are not possible, selects a target path maintenance trajectory as the trajectory plan, and sets the trajectory profile of the trajectory plan so that, for example, the vehicle 1 decelerates along the target path so as not to collide with an obstacle ahead.

[0071] On the other hand, if steering avoidance is required (Step S3: YES) and the map information 70A indicates that the driving path where lane changes are possible is on the left, the trajectory planning unit 11 selects a left avoidance trajectory as the trajectory plan (Step S5). Also, if steering avoidance is required (Step S3: YES) and the map information 70A indicates that the driving path where lane changes are possible is on the right, the trajectory planning unit 11 selects a right avoidance trajectory as the trajectory plan (Step S6). When selecting a left avoidance trajectory or a right avoidance trajectory, the trajectory planning unit 11 sets a trajectory profile for the trajectory plan based on the trajectory model 70c such that the movement trajectory from the vehicle 1's current position to the drivable path is appropriate.

[0072] The trajectory planning unit 11 repeatedly performs the above processing at predetermined intervals (in this case, 5 Hz).

[0073] Figure 6 is a flowchart showing an example of the operation of the motion planning unit 12.

[0074] In step S11, the motion plan determination unit 12 first determines, based on the surrounding object information, whether or not there is an obstacle approaching that could cause collision with the vehicle 1. If there is an obstacle approaching that could cause collision (step S11: YES), the motion plan determination unit 12 proceeds to step S13. On the other hand, if there is no obstacle approaching that could cause collision (step S11: NO), the motion plan determination unit 12 selects normal motion as the motion plan (step S12). Normal motion means moving along the trajectory plan, and the motion plan determination unit 12 calculates the motion profile of the motion plan (i.e., the target acceleration / deceleration and target yaw rate at each point in time) based on the vehicle's driving state information and the vehicle's current position information, in order to satisfy the target driving position and target vehicle speed of the vehicle 1 at each point in time set in the trajectory plan.

[0075] In step S13, the motion plan determination unit 12 determines whether a collision between the vehicle 1 and the obstacle detected in step S11 is unavoidable by braking. If the collision is unavoidable by braking (step S13: NO), the motion plan determination unit 12 selects an emergency stop motion as the motion plan (step S14). When an emergency stop motion is selected, the motion plan determination unit 12 invalidates the currently set trajectory plan and sets a motion plan to bring the vehicle 1 to an emergency stop at a predetermined deceleration based on the motion model 70d for "emergency stop motion".

[0076] On the other hand, if avoidance is not possible by braking (Step S13: YES), the motion plan determination unit 12 selects emergency steering avoidance maneuver as the motion plan (Step S15). In this case, if the drivable path is in the right lane relative to the current position, the motion plan determination unit 12 performs emergency steering avoidance to the right lane. If the drivable path is in the right lane relative to the current position, the motion plan determination unit 12 performs emergency steering avoidance to the left lane. When emergency steering avoidance maneuver is selected, the motion plan determination unit 12 invalidates the currently set trajectory plan and sets a motion profile based on the motion model 70d for "emergency steering avoidance maneuver" that steers the vehicle 1 to the left or right while decelerating it at a predetermined deceleration rate.

[0077] The motion planning unit 12 repeatedly performs the above processing at predetermined intervals (in this case, 20 Hz).

[0078] [effect] As described above, in this embodiment, A control device for a vehicle that automatically travels along a predetermined target path, A trajectory planning determination unit determines, based on information about objects surrounding the vehicle, which trajectory plan to adopt as the future trajectory of the vehicle is a target path maintenance trajectory, a left avoidance trajectory, or a right avoidance trajectory. A motion plan determination unit determines, based on the surrounding object information, which motion plan to adopt as the future motion mode of the vehicle is either normal motion in accordance with the trajectory plan or emergency evasive motion that temporarily disables the trajectory plan. A vehicle control unit controls the vehicle so that the vehicle's driving state at each point in time conforms to the motion plan, based on the motion plan and information relating to the vehicle's driving state. Equipped with, The trajectory planning unit and the motion planning unit update the trajectory plan and motion plan sequentially, respectively, and the update frequency of the motion planning unit is higher than that of the trajectory planning unit. The control device was disclosed.

[0079] According to the vehicle control device of this embodiment, by using hierarchical planning, vehicle motion can be sequentially controlled based on a motion plan with a shorter computation time, rather than a trajectory plan with a longer computation time. Furthermore, this enables a robust driving plan, such as planning motion to avoid dangers that could not be anticipated during trajectory planning. In addition, by performing trajectory planning, which has a longer computation time, at a low cycle and motion planning, which has a shorter computation time, at a high cycle, it is possible to reduce the computational load on the control system when the vehicle is autonomously driven compared to when trajectory planning itself is performed at a high cycle.

[0080] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. [Industrial applicability]

[0081] The vehicle control device according to the present invention makes it possible to achieve robust vehicle control that can address risks that could not be anticipated during track planning. [Explanation of Symbols]

[0082] 1 vehicle 10 Control device 11. Trajectory Planning Department 12. Exercise Planning Department 13. Vehicle Control Unit 20 Vehicle drive system 30. Driving condition detection device 40 Location information acquisition device 50 Surrounding Information Acquisition Device 70 Storage device 70a Map Information 70b Driving Schedule Information 70c orbit model 70d motion model

Claims

1. A control device for a vehicle that automatically travels along a predetermined target path, A track planning determination unit determines, based on the surrounding information of the vehicle, which track plan to adopt as the future travel trajectory of the vehicle is a target path maintenance track, a left avoidance track, or a right avoidance track. A motion plan determination unit determines, based on the surrounding information, whether to adopt a normal motion in accordance with the trajectory plan or an emergency evasive motion that temporarily disables the trajectory plan as the future motion mode of the vehicle, A vehicle control unit controls the vehicle so that the vehicle's driving state at each point in time conforms to the motion plan, based on the motion plan and information relating to the vehicle's driving state. Equipped with, The trajectory planning unit and the motion planning unit update the trajectory plan and motion plan sequentially, respectively, and the update frequency of the motion planning unit is higher than that of the trajectory planning unit. Control device.

2. The aforementioned track plan includes time-series data relating to the target travel position and target speed of the vehicle at each future point in time. The motion plan includes time-series data relating to the target acceleration / deceleration and target yaw rate at each future point in time for the vehicle. The control device according to claim 1.

3. The track planning unit receives sequentially detected vehicle driving status information, vehicle current location information, and vehicle surrounding information. Based on this information, driving schedule information including the target route and set vehicle speed, map information, and track models for each configuration, the track planning unit calculates the track profile of the determined track plan. The control device according to claim 1.

4. The trajectory planning unit adopts the trajectory plan relating to the target path maintenance trajectory if no obstacle is detected in front of the vehicle in the surrounding information, and if it is not necessary to steer away from the obstacle or if it is not possible to steer away from the obstacle. If an obstacle is detected in front of the vehicle in the surrounding information, and it is possible to steer away from the obstacle, and it is necessary to steer away from the obstacle, the trajectory plan relating to the left avoidance trajectory or the right avoidance trajectory adopts the trajectory plan relating to the left avoidance trajectory or the right avoidance trajectory. The control device according to claim 3.

5. The motion plan determination unit receives sequentially detected vehicle driving state information, vehicle current position information, vehicle surrounding information, and information related to the trajectory plan from the trajectory plan determination unit. Based on this information and the motion model for each aspect, the motion plan determination unit calculates the motion profile of the motion plan. The control device according to claim 1.

6. The motion plan determination unit adopts the motion plan for normal motion if no obstacles that pose a collision risk are detected approaching the vehicle in the surrounding information, and adopts the motion plan for emergency evacuation motion if obstacles that pose a collision risk are detected approaching the vehicle in the surrounding information. The control device according to claim 1.

7. The aforementioned emergency evacuation maneuver includes an emergency stop maneuver and an emergency steering avoidance maneuver. The motion plan determination unit adopts the motion plan relating to the emergency stop motion when it is possible to avoid a collision between the vehicle and the obstacle by braking, and adopts the motion plan relating to the emergency steering avoidance motion when it is impossible to avoid a collision between the vehicle and the obstacle by braking. The control device according to claim 6.

8. When the trajectory planning unit adopts the trajectory plan relating to the left avoidance trajectory or the right avoidance trajectory, it identifies a traversable path adjacent to the target path based on the surrounding information or the map information, and creates the trajectory profile corresponding to that traversable path. The control device according to claim 4.

9. When the track planning unit adopts the track plan relating to the left avoidance track or the right avoidance track, if a drivable path adjacent to the target path is not identified by the surrounding information and the map information, it plans a new modified target path from the current vehicle position and the final target arrival position of the target path and creates the track profile. The control device according to claim 8.

10. The track planning unit calculates the track profile of the track plan based on the kinematic model of the vehicle motion model. The control device according to claim 1.

11. The motion planning unit calculates the motion profile of the motion plan based on the dynamics model of the vehicle motion model. The control device according to claim 1.

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