Vehicle control device

Abstract

Provided is a vehicle control device capable of realizing robust vehicle control capable of coping with unpredictable risks when making a trajectory plan when a vehicle is automatically driven. The present disclosure relates to a control device for a vehicle that automatically travels along a prescribed target route, comprising: a trajectory plan determination unit that determines which trajectory plan is taken as a future travel trajectory of the vehicle among a target route maintenance trajectory, a left avoidance trajectory, and a right avoidance trajectory; a motion plan determination unit that determines, as a future motion pattern of the vehicle, which motion plan is to be taken among normal motion in accordance with the trajectory plan and emergency retreat motion in which the trajectory plan is temporarily invalidated; and a vehicle control unit that controls the vehicle such that the traveling state of the vehicle at each time point conforms to the motion plan, the trajectory plan determination unit and the motion plan determination unit sequentially update the trajectory plan and the motion plan, respectively, and the update frequency of the motion plan determination unit is higher than the update frequency of the trajectory plan determination unit.

Description

TECHNICAL FIELD

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

[0002] In recent years, the development of ADAS (ADVANCED DRIVER ASSISTANCE SYSTEM) and automatic driving related technologies in the automobile field has been rapid. For example, as a function that automates a part of the driving operation, adaptive cruise control, a lane keeping assist system, emergency automatic braking, and the like have been put into practical use.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-62261

[0006] NON-PATENT DOCUMENTS

[0007] Non-Patent Document 1: Keisuke Yoneda, et al. "Trajectory optimization and state selection for urban automated driving", Artificial Life and Robotics, Volume 23, pages 474-480, (2018), Published: 22 September 2018.

[0008] Non-Patent Document 2: Pedro Bautista-Camino, et al. "Local Path Planning for Autonomous Vehicles Based on the Natural Behavior of the Biological Action- Perception Motion", Energies 2022, 15(5), 1769, Published: 27 February 2022.

[0009] 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. SUMMARY

[0010] Problem to be solved by the Invention

[0011] However, in such automatic driving related technology, a control system has been developed which is capable of acquiring object information around a host vehicle, generating a track plan of the host vehicle based on the acquired object information and map information, and causing the vehicle to travel in a manner following the track plan (for example, refer to Patent Literature 1).

[0012] However, in the vehicle control device of the prior art such as Patent Literature 1, the calculation time at the time of generating a track plan is long, and in the event of a risk that is unpredictable at the time of formulating a track plan, it is sometimes difficult to avoid danger. In addition, the calculation load in the track plan and the track following control is high, and it is sometimes difficult to update the instruction value of the vehicle motion at a high frequency required for automatic driving.

[0013] The present invention was made in view of the above problems, and aims to provide a control device of a vehicle capable of realizing a robust vehicle control that can cope with a risk that is unpredictable at the time of formulating a track plan.

[0014] Solution to Problem

[0015] The main content of the present invention, which solves the above technical problems, is a control device for a vehicle that automatically travels along a prescribed target path, the control device including:

[0016] a track plan decision section that decides which one of a track maintaining track on a target path, a left evasive track, and a right evasive track is adopted as a future travel track of the vehicle based on surrounding information of the vehicle;

[0017] a motion plan decision section that decides which one of a normal motion in accordance with the track plan and an emergency retreat motion that temporarily invalidates the track plan is adopted as a future motion pattern of the vehicle based on the surrounding information; and

[0018] a vehicle control section that controls the vehicle in a manner such that the travel state of the vehicle at each time point conforms to the motion plan based on the motion plan and information related to the travel state of the vehicle,

[0019] the track plan decision section and the motion plan decision section sequentially update the track plan and the motion plan, respectively, and the update frequency of the motion plan decision section is higher than that of the track plan decision section.

[0020] The vehicle control device according to the present invention enables robust vehicle control that can cope with unforeseen risks when formulating track plans. Furthermore, it reduces the computational load on the control system when enabling autonomous vehicle movement and allows for high-frequency vehicle motion control. Attached Figure Description

[0021] Figure 1 It is a diagram showing the structure of a vehicle.

[0022] Figure 2 It is a block diagram representing the functional structure of the control device.

[0023] Figure 3 This diagram illustrates an example of a vehicle's movement mode, where it automatically travels along a predetermined target path set in a driving schedule.

[0024] Figure 4 (A) is the orbital plan decided by the orbital planning department. Figure 4 (B) is a diagram illustrating the sports plan decided by the sports planning department.

[0025] Figure 5 This is a flowchart illustrating an example of the actions taken by the track planning decision-making department.

[0026] Figure 6 This is a flowchart illustrating an example of the actions performed by the action planning decision-making department.

[0027] Explanation of reference numerals in the attached figures

[0028] 1 vehicle

[0029] 10. Control device

[0030] 11. Track Planning Decision Department

[0031] 12 Sports Planning Decision-Making Department

[0032] 13 Vehicle Control Department

[0033] 20 Vehicle drive unit

[0034] 30 Driving Status Detection Device

[0035] 40 Location information acquisition device

[0036] 50 Surrounding Information Acquisition Devices

[0037] 70 Storage devices

[0038] 70a Map Information

[0039] 70b Driving Plan Information

[0040] 70c orbital model

[0041] 70d motion model Detailed Implementation

[0042] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, structural elements having substantially the same function are omitted from repeated description by using the same reference numerals.

[0043] [Vehicle Structure]

[0044] First, an example of the structure of a vehicle (hereinafter referred to as "vehicle 1") according to one embodiment of the present invention will be described. It should be noted that vehicle 1 of this embodiment is a vehicle equipped with a control device capable of performing automatic driving.

[0045] Figure 1 This is a diagram showing the structure of vehicle 1.

[0046] Vehicle 1 may be equipped with, for example, a vehicle drive unit 20, a driving status detection unit 30, a location information acquisition unit 40, a surrounding information acquisition unit 50, an HMI (Human Machine Interface) 60, a storage unit 70, and a control unit 10.

[0047] The vehicle drive unit 20 is a drive unit that moves the vehicle 1, and is configured to include, for example, a drive motor, a power transmission mechanism, a braking device, and a steering device. The vehicle drive unit 20 generates power, for example, through a drive motor, and transmits this power to the wheels via a power transmission mechanism (such as a helical shaft, differential gear, and drive shaft) to move the vehicle 1. It should be noted that the operation of the vehicle drive unit 20 is controlled by the control device 10.

[0048] The driving state detection device 30 comprises various sensors that detect the driving state of the vehicle 1. The driving state detection device 30 includes, for example, an accelerator opening sensor for detecting the accelerator opening degree; a steering angle sensor for detecting the steering angle of the steering system; an acceleration sensor for detecting the acceleration acting on the vehicle 1 in the forward and backward direction; a torque sensor for detecting the torque acting on the power transmission mechanism between the wheels and the engine of the vehicle 1; and a vehicle speed sensor for detecting the vehicle speed of the vehicle 1.

[0049] The location information acquisition device 40 detects the current location of the vehicle 1. The location information acquisition device 40, for example, has a GPS antenna that periodically receives GPS signals from multiple GPS satellites, determines the current location of the vehicle 1 using the GPS signals, and sends the location information of the vehicle 1 to the control device 10.

[0050] It should be noted that the location information acquisition device 40 can also detect the current position of the vehicle 1 as its relative position to surrounding objects. In this case, the location information acquisition device 40 can also be composed of an onboard camera, an infrared sensor, sonar, or radar, etc.

[0051] The surrounding information acquisition device 50 is a sensor that detects the position of objects existing around the vehicle 1, and may include, for example, an onboard camera, an infrared sensor, sonar, or radar. The surrounding information acquisition device 50 is, for example, disposed at the four corners of the vehicle 1 so as to detect objects in all directions around the vehicle 1. The surrounding information acquisition device 50 outputs the detected information about objects around the vehicle 1 to the control device 10.

[0052] It should be noted that, more preferably, both radar and a vehicle-mounted camera are used as the surrounding information acquisition device 50. The vehicle-mounted camera is preferably used to determine the two-dimensional position of surrounding objects. In addition, the radar is preferably used to accurately detect the distance between itself and surrounding objects.

[0053] The surrounding information acquired by the surrounding information acquisition device 50 (equivalent to the "surrounding information" of the present invention) includes, for example, attribute information of pedestrians, bicycles, vehicles, etc., as well as their current position and current velocity vector.

[0054] HMI60 is a user interface, such as a touchscreen or keyboard, that accepts input from a user (hereinafter referred to as "user") riding in vehicle 1. HMI60 is configured, for example, to accept input such as commands to be executed during autonomous driving.

[0055] Storage device 70 may be an auxiliary storage device such as an HDD (hard disk drive), SSD (solid state drive), or USB memory. Storage device 70 may store, for example, control program 70e for enabling vehicle 1 to drive automatically, as well as data such as map information 70a, driving plan information 70b, track model 70c, and motion model 70d.

[0056] Map information 70a is, for example, a database that stores road maps and their coordinates in association with map data. The road map in map information 70a is composed of road information such as the location of intersections, the location of traffic lights, and the number of lanes. The coordinates of the road map are set based on latitude and longitude, and a specified location (e.g., intersections surrounding vehicle 1).

[0057] It should be noted that, for example, map information 70a can be referred to in order to determine the target path when the vehicle 1 is driving automatically, or to determine the reference path when changing lanes from the current driving lane.

[0058] The driving schedule information 70b is, for example, information set at the start of driving of vehicle 1 related to the target path from the starting point to the destination. The target path of the driving schedule information 70b is stored, for example, in association with the road map of map information 70a, and specifies the target location on the road map that vehicle 1 should travel to at each point in time during driving. It should be noted that, in cases where the driving path has multiple lanes, the target path also includes settings such as which lane to travel in. Furthermore, the legal speed stipulated by road regulations, such as the target speed under normal circumstances (hereinafter referred to as the "schedule setting speed"), is also stored in association with the target path of the driving schedule information 70b.

[0059] It should be noted that the driving plan information 70b is generated, for example, by the driving plan generation function of the control device 10, based on the driving start location and driving destination location input by the user. Since this driving plan generation function is a known technology, its description is omitted here. However, the driving plan information 70b may also be a driving plan generated by an external device (not shown) obtained via a communication circuit or the like.

[0060] The track model 70c is model data used to generate the track plan of the vehicle 1, which is referenced by the track planning determination unit 11 of the control device 10 (described later). The track model 70c stores, for example, track models related to the target path maintaining track, the left avoidance track, and the right avoidance track (see [reference]). Figure 4 ).

[0061] The motion model 70d is model data used to generate the motion plan of the vehicle 1 referenced by the motion plan determination unit 12 of the control device 10 (described later). As the motion model 70d, for example, it stores motion models (see [reference]) related to emergency avoidance movements (here, emergency stop movements or emergency steering avoidance movements) that temporarily invalidate the normal movement or track plan according to the track plan. Figure 4 ).

[0062] It should be noted that 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.

[0063] The control unit 10 is an electronic control unit that provides unified control over all parts of the vehicle 1. While referring to sensor information from the driving state detection device 30, the control unit 10 controls various parts of the vehicle drive system 20 (e.g., the output of the drive motor, the engagement and disengagement of the clutch, the gear shifting of the automatic transmission, and the steering angle of the steering device) to optimize the driving state of the vehicle 1. It should be noted that the control unit 10 is configured to control the vehicle drive system 20 to perform automatic driving (meaning autonomous driving, the same applies hereinafter) of the vehicle 1.

[0064] The control device 10 is configured to include, for example, a CPU (Central Processing Unit) 10a, a ROM (Read-Only Processor) 10b, a RAM (Random Access Memory) 10c, an input port (not shown), and an output port (not shown). The CPU 10a in the control device 10 reads a program corresponding to the processing content from the ROM 10b or the storage device 70, expands it in the RAM 10b, and coordinates with the expanded program to centrally control the operation of each block. At this time, various data stored in the storage device 70 are referenced.

[0065] In addition, the control device 10 is interconnected with the vehicle drive unit 20, driving status detection device 30, location information acquisition device 40, surrounding information acquisition device 50, HMI 60 and storage device 70 via an in-vehicle network (e.g., a communication network based on the CAN communication protocol), and is able to send and receive necessary data and control signals to each other.

[0066] [Structure of the vehicle's control system]

[0067] Next, the structure of the control device 10 of this embodiment will be described. It should be noted that, here, only the structure described is that the control device 10 of this embodiment enables the vehicle 1, which travels automatically along a target path set as a driving schedule, to avoid surrounding objects existing at each location.

[0068] Figure 2 This is a block diagram illustrating the functional structure of the control device 10. It should be noted that... Figure 2 The arrows in the diagram indicate the signal transmission path.

[0069] Figure 3 This diagram illustrates an example of the movement mode of vehicle 1, which automatically travels along a target path defined in a driving schedule.

[0070] Figure 4 The orbital plan decided by the Orbital Planning Decision-Making Department 11 ( Figure 4 (A) and the sports plan decided by the sports planning decision-making department 12 ( Figure 4 The diagram (B) is used to illustrate this.

[0071] The control device 10 has the functions of a track planning decision unit 11, a motion planning decision unit 12, and a vehicle control unit 13, which enable the vehicle 1 to move automatically.

[0072] As described above, the vehicle 1 in this embodiment is configured to automatically travel along a predetermined target path set in a driving schedule under the control of the control device 10. However, in actual driving of the vehicle 1, if... Figure 3As shown, various obstacles exist along the driving path, so the control device 10 needs to move the vehicle 1 while avoiding these obstacles. These obstacles include, for example, pedestrians, other vehicles, and objects that have fallen onto the driving path.

[0073] It should be explained that Figure 3 In this context, LL represents the road that vehicle 1 is traveling on (e.g., a 2-lane road), L1 represents the target path, L2 represents other drivable paths on roads adjacent to the target path (e.g., lanes different from the lanes of the target path L1), and B1 represents obstacles present on the target path (e.g., other vehicles stopped on the road).

[0074] The track planning and decision unit 11 is a function used to stably guide vehicle 1 along a target path while avoiding obstacles, based on information about objects surrounding vehicle 1. That is, in situations such as... Figure 4 In the case shown in (A), the track planning decision unit 11 generates a track plan to avoid such obstacles.

[0075] It should be noted that, Figure 4 (A) shows a pattern that generates a track plan (i.e., a right avoidance track) to avoid an obstacle B1 detected ahead of the driving path (i.e., the target path L1), causing the vehicle 1 to change its lane from the target path L1 to another drivable path L2 (e.g., a lane different from the lane of the target path L1) adjacent to the right side of the target path.

[0076] Here, the track planning decision unit 11 is input with successively detected vehicle 1 driving status information (information from driving status detection device 30), vehicle 1 current position information (information from position information acquisition device 40), and vehicle 1 surrounding object information (information from surrounding information acquisition device 50). Based on this information, information related to the driving schedule (here, the target path and the speed of the vehicle are set) 70b, map information 70a, and track models 70c for each mode, the track planning decision unit 11 generates a track plan (hereinafter referred to as "track plan") that serves as the driving track of vehicle 1 for a predetermined period starting from the next moment.

[0077] It should be noted that, for example, the "track plan" refers to the time-series data related to the target driving position and target speed of vehicle 1 at each point in time during a predetermined period (e.g., 10 seconds after the current time) starting from the next time. (e.g., time-series points of target driving position and target speed at 100 points every 0.1 seconds starting from the next time). It should also be noted that in this embodiment, the track plan set by the track plan determination unit 11 is not directly used as the indication value for vehicle motion control. Therefore, to reduce computational load, it is preferable to generate the track plan based on future predictions of the vehicle position using a kinematic model that has a lower computational load in the vehicle motion model.

[0078] Specifically, firstly, the track planning decision unit 11 uses a predetermined cost function based on the surrounding object information of the vehicle 1 to determine which track plan to adopt among the target path maintaining track, the left avoidance track, and the right avoidance track. For example, if no obstacle is detected in the surrounding object information around the vehicle 1 (e.g., in front), the track planning decision unit 11 selects the target path maintaining track. On the other hand, if an obstacle is detected in the surrounding object information around the vehicle 1 (e.g., in front), the track planning decision unit 11 selects either the left avoidance track or the right avoidance track as the track plan. In this case, whether to adopt the left avoidance track or the right avoidance track depends on the drivable path adjacent to the target path.

[0079] Here, "target path maintaining track" refers to the track that travels on the target path, "left avoidance track" refers to the track that changes lanes by shifting left from the target path to the travel position, and "right avoidance track" refers to the track that changes lanes by shifting right from the target path to the travel position. These track models 70c are pre-stored in the storage device 70, and the track planning decision unit 11 generates a track plan based on the track models 70c.

[0080] For example, in the "target path maintenance track", the track planning decision unit 11 generates a track plan based on the track model 70c used for the "target path maintenance track" so that the vehicle travels on the target path set as the travel schedule at the speed set in the schedule (e.g., the legal speed).

[0081] On the other hand, in the "left avoidance track" or "right avoidance track," the track planning and determination unit 11 refers to a drivable path adjacent to the target path and calculates a track profile according to the track model 70c for the "left avoidance track" or "right avoidance track" to make the movement trajectory from the current position of vehicle 1 to the drivable path an appropriate movement trajectory. This track profile set on the track model 70c is not particularly limited; for example, it can be a trajectory that draws a spline curve from the current position to the target position. For example, in the case where the "left avoidance track" or "right avoidance track" is a lane change starting from the current position of vehicle 1, the movement trajectory becomes a spline curve that smoothly connects the centerline of the lane change destination lane from the current position. The target vehicle speed can also be set to a value different from the speed set in the plan table to facilitate a smooth lane change.

[0082] It should be noted that the track planning decision unit 11 may also use, for example, the well-known Frenet Frame (refer to Non-Patent Document 1) or the well-known Attractor Dynamic Approach (refer to Non-Patent Document 2) as a method for calculating the track profile of the track plan.

[0083] It should be noted, for example, that drivable paths adjacent to the target path can be determined based on map information 70a. For example, such as... Figure 4 As shown in (A), on map information 70a, the road on which vehicle 1 travels is a two-lane road, and when the target path is set as one lane (e.g., left lane L1), the other lane (e.g., right lane L2) is identified as a drivable path. By matching the map with the current location of vehicle 1, the road information of the current location of vehicle 1 (map information 70a) can be obtained.

[0084] On the other hand, even when the driving path of vehicle 1 is not specified on map information 70a, a drivable path can be determined using surrounding condition information from the surrounding information acquisition device 50. Furthermore, in off-road environments (where a drivable path is not specified on map information 70a and a drivable path cannot be determined using surrounding condition information from the surrounding information acquisition device 50), a new drivable path from the current vehicle position to the target location that will not collide with obstacles can be planned and used as the target path. Such path planning can also be implemented at a lower update frequency than track planning.

[0085] The track planning decision unit 11 updates the track plan sequentially. The update frequency of the track plan in the track planning decision unit 11 depends on the performance of the CPU 10a constituting the control device 10, and is preferably 5 Hz or higher.

[0086] It should be noted that during the period before vehicle 1 crosses the obstacle, the track planning determination unit 11 maintains and updates the track plan related to the "left avoidance track" or "right avoidance track". Then, if it is detected from the surrounding object information that vehicle 1 has crossed the obstacle, the track planning determination unit 11 selects the "target path maintenance track" as the track plan. When returning vehicle 1 from the position where the lane has changed to the target path, the track planning determination unit 11 can also return to the target path through feedback control performed by the vehicle control unit 13 (motion planning determination unit 12). However, in this case, the track planning determination unit 11 preferably generates a track plan that makes the movement trajectory of vehicle 1 from the position where the lane has changed to the target path a spline curve. In this case, for example, a track model 70c for the "return track" is prepared in advance, and the track planning determination unit 11 is set to select the "return track" after the "left avoidance track" or "right avoidance track".

[0087] As described above, the function of the track planning and decision unit 11 enables vehicle 1 to travel stably along the target path while avoiding obstacles. However, in actual operation of vehicle 1, such as... Figure 4 As shown in (B), there may also be an obstacle B2 that suddenly and rapidly approaches vehicle 1. In this case, the calculation time for formulating the track plan is long, and in the event of unforeseen risks during the track planning process, it may be difficult to avoid the danger.

[0088] The motion plan determination unit 12 is designed to temporarily invalidate the track plan generated in the track plan determination unit 11 and cause the vehicle 1 to take an emergency avoidance maneuver when an obstacle suddenly and rapidly approaches the vehicle 1 is detected. That is, the motion plan determination unit 12 can generate a motion plan to avoid a collision with such an obstacle and cause the vehicle 1 to travel according to that motion plan. It should be noted that in... Figure 4 (B) shows a pattern for generating a motion plan that causes vehicle 1, which is traveling on a right-avoidance track, to come to an emergency stop in order to avoid an obstacle B2 that is rapidly approaching vehicle 1.

[0089] Here, the motion planning decision unit 12 is input with successively detected vehicle 1 driving status information (information from driving status detection device 30), vehicle 1 current position information (information from position information acquisition device 40), vehicle 1 surrounding object information (information from surrounding information acquisition device 50), and track planning information from track planning decision unit 11. Then, based on this information and motion model 70d, the motion planning decision unit 12 generates a motion plan (hereinafter referred to as "motion plan") that is the motion mode of vehicle 1 for a predetermined period from the next moment.

[0090] It should be noted that, for example, a "motion plan" refers to time-series data related to the target acceleration / deceleration and target yaw rate of vehicle 1 at various points in time during a specified period (e.g., 1 second later) starting from the next moment from the current moment (e.g., time points of target acceleration / deceleration and target yaw rate at 10 points every 0.1 seconds starting from the next moment). It should be noted that since the motion plan set by the motion plan determination unit 12 is directly adopted as the indication value for vehicle motion control, it is preferable to generate the motion plan based on a future prediction of the vehicle position using a vehicle motion model, i.e., a dynamic model, which is more detailed than a kinematic model.

[0091] Specifically, firstly, the motion planning decision unit 12 uses a prescribed cost function based on information about the surrounding objects of the vehicle 1 to determine which motion plan to adopt among normal motion according to the track plan, emergency stop motion that temporarily invalidates the track plan, and emergency turning avoidance motion.

[0092] "Normal movement" refers to movement according to the planned trajectory. "Emergency stop movement" and "emergency turning avoidance movement" refer to movements that temporarily invalidate the planned trajectory and initiate pre-set emergency avoidance movements. "Emergency stop movement" is a movement that stops vehicle 1 by accelerating or decelerating the target on the current travel track. On the other hand, "emergency turning avoidance movement" is a movement that avoids a collision between vehicle 1 and an approaching obstacle B2 if an emergency stop on the current travel track might cause vehicle 1 to collide with the obstacle B2.

[0093] That is, when no rapidly approaching obstacle is detected around vehicle 1, the motion planning decision unit 12 selects "normal motion". In this case, the motion planning decision unit 12 calculates the motion profile of the motion plan (i.e., the target acceleration / deceleration and target yaw rate at each time point) based on the driving state information and the current position information of vehicle 1, so as to satisfy the target driving position and target speed of vehicle 1 at each time point set in the track plan.

[0094] On the other hand, when the surrounding object information detects a rapidly approaching obstacle in the surrounding object information of vehicle 1, the motion planning decision unit 12 switches from "normal motion" to "emergency stop motion" or "emergency steering avoidance motion". When the motion planning decision unit 12 selects "emergency stop motion" as the motion plan, it sets the motion profile of the emergency stop motion based on the motion model 70d for "emergency stop motion". For example, in emergency stop motion, based on the current vehicle speed, a deceleration motion profile is set to bring vehicle 1 to an emergency stop without applying excessive G-force to the occupants. In addition, when "emergency steering avoidance motion" is selected as the motion plan, the motion profile of the emergency steering avoidance motion is set based on the motion model 70d for "emergency steering avoidance motion". For example, in emergency steering avoidance motion, based on the current vehicle speed, a motion profile is set to decelerate without applying excessive G-force to the occupants and turn to avoid the obstacle by drawing a spline curve to the left or right. It should be noted that since emergency turning avoidance is a highly risky avoidance action, the preferred motion planning decision unit 12 first studies whether it is possible to avoid the obstacle by braking (emergency stop) and implements emergency turning avoidance as a last resort.

[0095] It should be noted that the motion planning decision unit 12 may, for example, use the well-known dynamic window approach (refer to Non-Patent Document 3) as a method for calculating the motion profile of the motion plan.

[0096] The motion planning decision unit 12 determines whether to choose "emergency stop motion" or "emergency turn avoidance motion" as the motion plan based on the distance between vehicle 1 and the rapidly approaching obstacle, the predicted trajectories of both, or information on drivable paths around vehicle 1.

[0097] 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 constituting the control device 10, and is preferably 10Hz 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. As a result, even if an obstacle rapidly approaches the vehicle 1 (i.e., an unforeseen risk when formulating the track plan), danger can be avoided.

[0098] The vehicle control unit 13 acquires the motion plan generated by the motion plan determination unit 12 and the driving status information of the vehicle 1 output from the driving status detection device 30. Then, the vehicle control unit 13 performs feedback control on the vehicle drive unit 20 to ensure that the driving status of the vehicle 1 at each time point conforms to the motion plan.

[0099] Figure 5This is a flowchart illustrating an example of the actions of the track planning decision-making unit 11.

[0100] In step S1, the track planning determination unit 11 first determines whether there is an obstacle ahead on the target path based on surrounding object information. If there is an obstacle ahead (step S1: Yes), the track planning determination unit 11 proceeds to step S3. Conversely, if there is no obstacle ahead (step S1: No), the track planning determination unit 11 selects a target path maintaining track as the track plan (step S2). It should be noted that, in this target path maintaining track, for example, a track outline is set so that the vehicle 1 travels on the target path at the speed set in the plan.

[0101] In step S3, while driving vehicle 1 on the target path, the track planning determination unit 11 determines whether it is necessary to steer to avoid the obstacle detected in step S1. If steering is not required (step S3: No), the track planning determination unit 11 selects the target path maintaining track as the track plan (step S4). Here, if the speed of the obstacle detected in step S1 is sufficiently high, the track planning determination unit 11 maintains the target path maintaining track without taking unnecessary avoidance actions. Furthermore, the track planning determination unit 11 refers to map information 70a and, if lane changing is not possible, selects the target path maintaining track as the track plan, for example, setting the track outline of the track plan by slowing vehicle 1 on the target path to avoid collision with the obstacle ahead.

[0102] On the other hand, when a turning maneuver is required to avoid a lane (step S3: Yes), and the driving path that can be changed to the left according to map information 70a is on the left, the track planning determination unit 11 selects a left avoidance track as the track plan (step S5). Additionally, when a turning maneuver is required to avoid a lane (step S3: Yes), and the driving path that can be changed to the right according to map information 70a is on the right, the track planning determination unit 11 selects a right avoidance track as the track plan (step S6). When selecting either a left or right avoidance track, the track planning determination unit 11 sets the track profile of the track plan based on the track model 70c so that the movement trajectory from the current position of vehicle 1 to the driving path becomes an appropriate movement trajectory.

[0103] The track planning decision unit 11 repeatedly performs the above-described process at a predetermined interval (5 Hz in this case).

[0104] Figure 6 This is a flowchart illustrating an example of the action content of the motion planning decision section 12.

[0105] In step S11, the motion plan determination unit 12 first determines, based on surrounding object information, whether there is an obstacle that could potentially collide with vehicle 1. If an obstacle that could potentially collide is present (step S11: Yes), the motion plan determination unit 12 proceeds to step S13. Alternatively, if no obstacle that could potentially collide is present (step S11: No), the motion plan determination unit 12 selects normal motion as the motion plan (step S12). It should be noted that normal motion refers to motion according to the track plan. 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 time point) based on the vehicle 1's driving state information and current position information to satisfy the target driving position and target speed of vehicle 1 at each time point set in the track plan.

[0106] In step S13, the motion plan determination unit 12 determines whether the collision between vehicle 1 and the obstacle detected in step S11 cannot be avoided by braking. If it can be avoided by braking (step S13: no), the motion plan determination unit 12 selects an emergency stop motion as the motion plan (step S14). It should be noted that when an emergency stop motion is selected, the motion plan determination unit 12 invalidates the currently set track plan and sets a motion plan based on the motion model 70d for "emergency stop motion" so that vehicle 1 comes to an emergency stop at a specified deceleration.

[0107] On the other hand, if braking is not an option to avoid the situation (step S13: Yes), the motion planning unit 12 selects an emergency steering avoidance motion 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 planning unit 12 performs an emergency steering avoidance motion towards the right lane. If the drivable path is in the left lane relative to the current position, the motion planning unit 12 performs an emergency steering avoidance motion towards the left lane. It should be noted that when an emergency steering avoidance motion is selected, the motion planning unit 12 invalidates the currently set track plan and sets a steering avoidance motion profile based on the motion model 70d used for "emergency steering avoidance motion," so that the vehicle 1 decelerates at a predetermined deceleration while simultaneously drawing a spline curve to the left or right.

[0108] The motion planning decision unit 12 repeatedly performs the above-described process at predetermined intervals (20 Hz in this case).

[0109] [Effect]

[0110] As described above, this embodiment discloses a control device for a vehicle that automatically travels along a predetermined target path. The control device includes:

[0111] The track planning decision unit, based on information about objects surrounding the vehicle, determines which track plan among the target path maintaining track, the left avoidance track, and the right avoidance track to adopt as the future driving track of the vehicle.

[0112] The motion planning decision unit, based on the surrounding object information, determines which motion plan to adopt as the vehicle's future motion mode: normal motion according to the track plan, or emergency retreat motion that temporarily invalidates the track plan; and

[0113] The vehicle control unit controls the vehicle in a manner that, based on the motion plan and information related to the vehicle's driving state at each point in time, the driving state of the vehicle conforms to the motion plan.

[0114] The track planning decision unit and the motion planning decision unit update the track plan and the motion plan sequentially, respectively, with the motion planning decision unit updating more frequently than the track planning decision unit.

[0115] The vehicle control device according to this embodiment, by using a hierarchical planning approach, can sequentially control vehicle movement based on a shorter motion plan rather than a long-calculation-time track plan. Furthermore, this enables robust driving plans, such as planning evasive movements to address unforeseen risks during track planning. Moreover, by implementing the long-calculation-time track plan with a low cycle and the short-calculation-time motion plan with a high cycle, the computational load on the control system when enabling autonomous vehicle movement is reduced compared to implementing the track plan itself with a high cycle.

[0116] The above description details specific examples of the present invention, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes techniques that have undergone various modifications and alterations to the specific examples described above.

[0117] This application is based on U.S. Patent Application No. 63 / 705,132, filed on October 9, 2024, and Japanese Patent Application No. 2025-012996, filed on January 29, 2025, the contents of which are incorporated herein by reference.

[0118] Industrial applicability

[0119] The vehicle control device according to the present invention enables robust vehicle control that can cope with unforeseen risks when formulating track plans.

Claims

1. A control device for a vehicle that automatically travels along a predetermined target path, the control device comprising: The track planning decision unit, based on the surrounding information of the vehicle, decides which track plan to adopt as the future travel track of the vehicle among the target path maintaining track, the left avoidance track, and the right avoidance track. The motion planning decision unit, based on the surrounding information, determines which motion plan to adopt as the future motion mode of the vehicle, either the normal motion according to the track plan or the emergency retreat motion that temporarily invalidates the track plan. as well as The vehicle control unit controls the vehicle in a manner that, based on the motion plan and information related to the vehicle's driving state at each point in time, the driving state of the vehicle conforms to the motion plan. The track planning decision unit and the motion planning decision unit update the track plan and the motion plan sequentially, respectively, with the motion planning decision unit updating more frequently than the track planning decision unit.

2. The control device as claimed in claim 1, wherein, The trajectory plan includes time-series data relating to the vehicle's target travel position and target speed at various future points in time. The motion plan includes time-series data relating to the vehicle’s target acceleration / deceleration and target yaw rate at various future points in time.

3. The control device as described in claim 1, wherein, The track planning and decision-making unit is input with successively detected vehicle driving status information, vehicle current location information, and vehicle surrounding information. Based on this information, the track planning decision unit calculates the track profile of the determined track plan, including the target path and the set speed, map information, and track models of various modes.

4. The control device as described in claim 3, wherein, When the track planning decision unit does not detect an obstacle in front of the vehicle in the surrounding information, does not need to turn to avoid the obstacle in front of the vehicle, or cannot turn to avoid the obstacle in front of the vehicle, it adopts the track plan related to the target path maintaining track. When an obstacle in front of the vehicle is detected in the surrounding information and it is possible to turn to avoid the obstacle, and it is necessary to turn to avoid the obstacle, it adopts the track plan related to the left avoidance track or the right avoidance track.

5. The control device as claimed in claim 1, wherein, The motion planning decision unit is input with successively detected vehicle driving status information, vehicle current position information, vehicle surrounding information, and track planning decision unit information related to the track plan. The motion planning decision unit calculates the motion profile of the motion plan based on this information and the motion models of each mode.

6. The control device as claimed in claim 1, wherein, When the motion planning decision unit does not detect the approach of any obstacle that could potentially collide with the vehicle in the surrounding information, it adopts the motion plan related to the normal motion; when the approach of any obstacle that could potentially collide with the vehicle is detected in the surrounding information, it adopts the motion plan related to the emergency retreat motion.

7. The control device as claimed in claim 6, wherein, The emergency retreat movement includes emergency stopping movement and emergency turning avoidance movement. When the motion planning decision unit can avoid a collision between the vehicle and the obstacle by braking, it adopts the motion plan related to the emergency stop motion; when it cannot avoid a collision between the vehicle and the obstacle by braking, it adopts the motion plan related to the emergency steering avoidance motion.

8. The control device as claimed in claim 4, wherein, When the track planning decision unit adopts the track plan related to the left avoidance track or the right avoidance track, it determines the drivable path that exists adjacent to the target path based on the surrounding information or the map information, and formulates the track profile corresponding to the drivable path.

9. The control device as claimed in claim 8, wherein, When the track planning decision unit adopts the track plan related to the left avoidance track or the right avoidance track, if no drivable path adjacent to the target path is determined based on the surrounding information and the map information, the track planning decision unit replans and corrects the target path according to the current vehicle position and the final target arrival position of the target path to formulate the track profile.

10. The control device as claimed in claim 1, wherein, The track planning decision unit calculates the track profile of the track plan based on the kinematic model of the vehicle motion model.

11. The control device as claimed in claim 1, wherein, The motion planning decision unit calculates the motion profile of the motion plan based on the dynamic model of the vehicle motion model.

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