Vehicle control device and vehicle control method

Abstract

To provide a vehicle control device and method which can prevent a crew member from feeling troublesome while securing safe distance between a vehicle and an obstruction.SOLUTION: A vehicle control device (100) comprises a camera (21) which acquires track information concerning a track (6) of a vehicle (1), a radar (22), a navigation system (30) and an ECU (10) which is configured so as to detect position of an object (OB) in front of the vehicle, to repeatedly set a target travel route in the track based upon the camera which repeatedly updates the position, the radar and the track information and the position of the object and to control the vehicle so that the vehicle travels along the target travel route. The ECU is configured so that it is difficult for a following target travel route to be set in a region closer to the object than the set target travel route if distance between the position of the object after update by the camera and the radar and the target travel route which is set based upon the position of the object before update is larger than the distance between the position of the object before update and the set target travel route.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device and a vehicle control method that set a travel path for a vehicle and control the vehicle based on this travel path. [Background technology]

[0002] Conventionally, control devices are known that perform autonomous driving of a vehicle by planning the vehicle's movement path based on the results of recognizing the vehicle's external environment, correcting the planned movement path based on the results of recognizing obstacles in the external environment, and controlling the vehicle's movement based on the corrected movement path (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-146905 [Overview of the project] [Problems that the invention aims to solve]

[0004] In conventional technologies, such as those described in Patent Document 1, obstacles are recognized using sensors such as cameras and radar, and the closer the vehicle gets to the obstacle, the more accurately its position and shape can be detected. Therefore, as the vehicle moves along a planned route and approaches an obstacle, it may be found that the distance between the obstacle and the route is closer or further than expected.

[0005] In conventional technology, when a travel path is set to avoid obstacles and follow the center position of the driving lane, if it is discovered as the vehicle progresses that the position of an obstacle is closer to the travel path than expected, the travel path is corrected to move away from the updated position of the obstacle. If it is discovered that the position of the obstacle is further from the travel path than expected, the travel path is corrected to move closer to the center position of the driving lane. In this way, if the travel path is corrected each time the position of an obstacle is updated as the vehicle progresses, vehicle control is executed in response to the travel path correction, resulting in frequent changes in the vehicle's behavior, which can be annoying for the occupants.

[0006] The present invention was made to solve these problems and aims to provide a vehicle control device and a vehicle control method that can ensure a safe distance between the vehicle and obstacles while preventing inconvenience to the occupants. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the present invention provides a vehicle control device comprising: a road information acquisition device that acquires road information relating to the road the vehicle is traveling on; an object detection device that detects the position of an object in front of the vehicle and repeatedly updates the position; and a controller configured to repeatedly set a target driving path on the road based on the road information and the position of the object, and to control the vehicle so that the vehicle travels along the target driving path. The controller is configured such that if the distance between the updated position of the object by the object detection device and the target driving path set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target driving path, it is difficult to set the next target driving path in an area closer to the object than the set target driving path.

[0008] According to the present invention configured in this manner, if the distance between the updated position of an object detected by the object detection device and the target driving path set based on the object's position before the update is greater than the distance between the object's position before the update and the set target driving path, the controller makes it difficult to set the next target driving path in an area closer to the object than the set target driving path. Therefore, when the object's position is updated in a direction away from the set target driving path, it is possible to suppress the setting of a target driving path that approaches the updated position of the object. This makes it possible to suppress frequent changes in vehicle behavior due to changes in the target driving path, ensuring a safe distance between the vehicle and obstacles while preventing occupants from feeling inconvenienced.

[0009] In other words, the present invention relates to a vehicle control device comprising: a road information acquisition device that acquires road information relating to the road a vehicle is traveling on; an object detection device that detects the position of an object in front of the vehicle and repeatedly updates the position; and a controller configured to repeatedly set a target road path on the road based on the road information and the position of the object, and to control the vehicle so that the vehicle travels along the target road path, wherein the controller is configured to exclude the area closer to the object than the set target road path from the area where the next target road path is set if the distance between the updated position of the object by the object detection device and the target road path set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target road path.

[0010] According to the present invention configured as described above, when the distance between the position of the object after update by the object detection device and the target travel route set based on the position of the object before update is greater than the distance between the position of the object before update and the set target travel route, the controller excludes an area closer to the object than the set target travel route from the area where the next target travel route is set. Therefore, when the position of the object is updated in a direction away from the set target travel route, a target travel route that approaches the position of the object after update is not set. As a result, it is possible to prevent frequent changes in the vehicle behavior associated with changes in the target travel route, and it is possible to prevent the passengers from feeling annoyance while ensuring a safe distance between the vehicle and the obstacle.

[0011] In the present invention, preferably, the controller sets a plurality of travel route candidates as candidates for setting the target travel route based on the travel route information, obtains a route cost for each of the plurality of travel route candidates based on the travel route information and the position of the object in front of the vehicle, increases the route cost of the travel route candidate as the distance between the position of the object and the travel route candidate decreases, increases the route cost of the travel route candidate as the distance between the center line of the own lane in which the vehicle travels on the travel route and the travel route candidate increases, sets the travel route candidate with the minimum route cost among the plurality of travel route candidates as the target travel route, and when the distance between the position of the object after update by the object detection device and the target travel route set based on the position of the object before update is greater than the distance between the position of the object before update and the set target travel route, the route cost of the travel route candidate passing through an area closer to the object than the set target travel route is configured to be higher than the route cost of the travel route candidate passing through the set target travel route.

[0012] According to the present invention configured as described above, when the distance between the updated position of the object by the object detection device and the target travel route set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target travel route, the path cost of the travel route candidate passing through the area closer to the object than the set target travel route is made higher than the path cost of the travel route candidate passing through the set target travel route. Therefore, when the position of the object is updated in the direction away from the set target travel route, it is difficult to set the travel route candidate approaching the updated position of the object as the next target travel route, or it can be made not to be set as the next target travel route. Thereby, it is possible to prevent frequent changes in the vehicle behavior accompanying changes in the target travel route, and it is possible to prevent the passengers from feeling annoyance while ensuring a safe distance between the vehicle and the obstacle.

[0013] From another aspect, the present invention is a vehicle control method executed by a control device including a computer, the method including: obtaining travel route information regarding the travel route of the vehicle; detecting the position of an object in front of the vehicle and repeatedly updating the position; repeatedly setting a target travel route on the travel route based on the travel route information and the position of the object; and controlling the vehicle to travel along the target travel route. The step of setting the target travel route includes making it difficult to set the next target travel route in an area closer to the object than the set target travel route when the distance between the updated position of the object in the step of repeatedly updating the position of the object and the target travel route set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target travel route. Also according to the present invention configured as described above, it is possible to prevent the passengers from feeling annoyance while ensuring a safe distance between the vehicle and the obstacle.

[0014] In other words, the present invention is a vehicle control method performed by a control device equipped with a computer, comprising the steps of: acquiring road information relating to the road the vehicle is traveling on; detecting the position of an object in front of the vehicle and repeatedly updating the position; repeatedly setting a target road path on the road based on the road information and the position of the object; and controlling the vehicle so that the vehicle travels along the target road path, wherein the step of setting the target road path includes, if the distance between the updated position of the object in the step of repeatedly updating the position of the object and the target road path set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target road path, excluding the area closer to the object than the set target road path from the area where the next target road path is set. With the present invention configured in this way, it is possible to ensure a safe distance between the vehicle and obstacles while preventing the occupants from experiencing any inconvenience. [Effects of the Invention]

[0015] According to the vehicle control device and vehicle control method of the present invention, it is possible to ensure a safe distance between the vehicle and obstacles while preventing the occupants from experiencing inconvenience. [Brief explanation of the drawing]

[0016] [Figure 1] This is an explanatory diagram of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. [Figure 2] This is a block diagram showing a schematic configuration of a vehicle control device according to an embodiment of the present invention. [Figure 3] This is an explanatory diagram illustrating the basic concept of vehicle control according to an embodiment of the present invention. [Figure 4] This is an explanatory diagram illustrating the basic concept of setting a target driving route according to an embodiment of the present invention. [Figure 5] This is a map defining the in-lane position cost according to an embodiment of the present invention. [Figure 6] This is a map that defines the obstacle location cost according to an embodiment of the present invention. [Figure 7] This is a map that defines the additional costs according to embodiments of the present invention. [Figure 8] This map shows an example of route costs according to an embodiment of the present invention. [Figure 9] This is a flowchart of the vehicle control process according to an embodiment of the present invention. [Modes for carrying out the invention]

[0017] Hereinafter, with reference to the attached drawings, a vehicle control device and method according to embodiments of the present invention will be described.

[0018] [System Configuration] First, the configuration of the vehicle control device according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is an explanatory diagram of a vehicle equipped with the vehicle control device, and Figure 2 is a block diagram of the vehicle control device.

[0019] The vehicle 1 according to this embodiment includes a drive source 2 such as an engine or electric motor that outputs driving force, a transmission 3 that transmits the driving force output from the drive source 2 to the drive wheels, brakes 4 that apply braking force to the vehicle 1, and a steering device 5 for steering the vehicle 1.

[0020] The vehicle control device 100 is configured to set a target driving path for the vehicle 1 and to control the vehicle 1 so that it drives along this target driving path (vehicle control). As shown in Figure 2, the vehicle control device 100 includes an ECU (Electronic Control Unit) 10 as a controller, a plurality of sensors, and a plurality of control systems.

[0021] Specifically, the multiple sensors include a camera 21, a radar 22, a vehicle speed sensor 23, an acceleration sensor 24, a yaw rate sensor 25, a steering angle sensor 26, an accelerator sensor 27, and a brake sensor 28 for detecting the behavior of the vehicle 1 and the driving operations of the occupants. Furthermore, the multiple sensors include a positioning system 29 and a navigation system 30 for detecting the position of the vehicle 1. The multiple control systems include a powertrain control module (PCM) 31 for controlling the drive source 2 and the transmission 3, a dynamic stability control system (DSC) 32 for controlling the drive source 2 and the brakes 4, and an electric power steering system (EPS) 33 for controlling the steering device 5.

[0022] Other sensors may include a surrounding sonar for measuring the distance and position of surrounding structures relative to the vehicle 1, corner radar for measuring the approach of surrounding structures at the four corners of the vehicle 1, and an interior camera for photographing the interior of the vehicle 1.

[0023] The ECU10 performs various calculations based on signals received from multiple sensors and transmits control signals to the PCM31, DSC32, and EPS33 to appropriately operate the drive source 2, transmission 3, brakes 4, and steering system 5. The ECU10 is composed of a computer equipped with one or more processors (typically CPUs), memory for storing various programs (ROM, RAM, etc.), input / output devices, and the like.

[0024] Camera 21 photographs the area around vehicle 1 and outputs image data. Based on the image data received from camera 21, ECU 10 identifies objects (for example, preceding vehicles, parked vehicles, pedestrians, roads, lane markings (lane boundaries, white lines, yellow lines), traffic signals, traffic signs, stop lines, intersections, obstacles, etc.). ECU 10 may also acquire information about objects from external sources, such as through traffic infrastructure or vehicle-to-vehicle communication. This allows for the identification of the type of object, its relative position, direction of movement, etc. Camera 21 corresponds to an example of a "road information acquisition device" and an "object detection device" in this invention.

[0025] Radar 22 measures the position and speed of objects (especially preceding vehicles, parked vehicles, pedestrians, objects on the road, etc.). For example, millimeter-wave radar can be used as radar 22. Radar 22 transmits radio waves in the direction of travel of vehicle 1 and receives reflected waves generated when the transmitted waves are reflected by the object. Based on the transmitted and received waves, radar 22 measures the distance between vehicle 1 and the object (e.g., inter-vehicle distance) and the relative speed of the object with respect to vehicle 1. In this embodiment, instead of radar 22, a laser radar or ultrasonic sensor may be used to measure the distance to the object and the relative speed. Alternatively, a position and speed measuring device may be configured using multiple sensors. Note that radar 22 corresponds to an example of an "object detection device" in the present invention.

[0026] The vehicle speed sensor 23 detects the speed of the vehicle 1 based on, for example, the rotational speed of the wheels or drive shaft. The acceleration sensor 24 detects the acceleration of the vehicle 1. This acceleration includes the acceleration in the longitudinal direction of the vehicle 1 and the acceleration in the lateral direction (i.e., lateral acceleration). In this specification, acceleration includes not only the rate of change of speed in the direction in which the speed increases, but also the rate of change of speed in the direction in which the speed decreases (i.e., deceleration).

[0027] The yaw rate sensor 25 detects the yaw rate of vehicle 1. The steering angle sensor 26 detects the rotation angle (steering angle) of the steering wheel of vehicle 1. The accelerator sensor 27 detects the amount the accelerator pedal is pressed. The brake sensor 28 detects the amount the brake pedal is pressed.

[0028] The positioning system 29 is a GPS system and / or a gyro system, and detects the position of vehicle 1 (current vehicle position information). The navigation system 30 stores map information internally and can provide map information to the ECU 10. Based on the map information and current vehicle position information, the ECU 10 identifies roads, intersections, traffic signals, buildings, etc., that exist around vehicle 1 (especially in the direction of travel). The map information may also be stored within the ECU 10. The navigation system 30 is also an example of a "road information acquisition device" in the present invention.

[0029] The PCM31 controls the power source 2 of the vehicle 1 to adjust the driving force of the vehicle 1. For example, the PCM31 controls the engine's spark plugs, fuel injectors, throttle valves, variable valve timing mechanism, transmission 3, and inverter that supplies power to the electric motor. When the ECU10 needs to accelerate or decelerate the vehicle 1, it sends a control signal to the PCM31 to adjust the driving force.

[0030] The DSC32 controls the vehicle's drive source 2 and brake 4 to perform deceleration control and attitude control. For example, the DSC32 controls the hydraulic pump and valve unit of the brake 4 and controls the drive source 2 via the PCM31. When the ECU10 needs to perform deceleration control or attitude control of the vehicle 1, it sends control signals to the DSC32 to adjust the drive force or generate braking force.

[0031] The EPS33 controls the steering system 5 of the vehicle 1. For example, the EPS33 controls an electric motor that applies torque to the steering shaft of the steering system 5. When the ECU10 needs to change the direction of travel of the vehicle 1, it sends a control signal to the EPS33 to change the steering direction.

[0032] [Basic Concepts of Vehicle Control] Next, with reference to Figure 3, the basic concepts of vehicle control performed by the ECU 10 described above in this embodiment will be explained. Figure 3 shows the vehicle 1 traveling along a target driving path set to avoid an object in front of the vehicle 1, with (a) showing the state at time t0, and (b) and (c) showing the state at time t1 after a predetermined time has elapsed from time t1.

[0033] First, the ECU 10 acquires road information from the camera 21, positioning system 29, navigation system 30, etc., and detects the position of an object OB (in the example of Figure 3, a truck parked on the road) in front of the vehicle 1 using the camera 21 and radar 22. The road information is information about the road, and includes information such as the shape of the road (straight, curve, curve curvature), road width, number of lanes, lane width, etc. This road information and the position of the object OB are repeatedly updated.

[0034] Next, the ECU 10 sets a target driving path on the road based on the road information and the position of object OB. The setting of the target driving path is performed repeatedly. Then, the ECU 10 sends control signals to at least one of the PCM 31, DSC 32, and EPS 33 so that vehicle 1 drives along the set target driving path.

[0035] In the example shown in Figure 3(a), at time t0, the ECU 10 acquires road information and detects the position of object OB. Based on this road information and the position of object OB, it sets the target road path R. t0 Set the target driving route R. t0 The system is set so that vehicle 1 moves forward while turning to the right so that it moves away from object OB, and the position of object OB and the set target travel path R t0 The distance to is d0. Next, the ECU10 sets the target driving path R as described above. t0 Vehicle 1 is controlled so that it travels along the designated path.

[0036] Figure 3(b) shows the target travel path R after time t0. t0The vehicle 1 turns right and moves forward while moving away from the object OB along [specific path], and shows the state when the ECU 10 acquires the road travel information and updates the position of the object OB at time t1. Specifically, as the vehicle 1 moves forward and approaches the object OB, the position detection accuracy of the object OB by the camera 21 and the radar 22 improves. As a result, the position of the object OB updated at time t1 is closer to the target travel route R than the position of the object OB before the update. t0 That is, based on the position of the object OB updated at time t1 and the position of the object OB at time t0, the distance d1 between the target travel route R t0 is smaller than the distance d0 between the position of the object OB detected at time t0 and the target travel route R t0 (d1 < d0). In this case, based on the road travel information and the position of the object OB updated at time t1, the ECU 10 sets a new target travel route R t1 (shown by the dotted line in Fig. 3(b)) that moves away from the updated position of the object OB.

[0037] Fig. 3(c) also shows the state when the vehicle 1 moves forward along the target travel route R t0 after time t0, and the ECU 10 acquires the road travel information and updates the position of the object OB at time t1. In the example of Fig. 3(c), different from Fig. 3(b), as the vehicle 1 moves forward and approaches the object OB, the position detection accuracy of the object OB by the camera 21 and the radar 22 improves. As a result, the position of the object OB updated at time t1 is farther from the target travel route R than the position of the object OB before the update. t0 That is, based on the position of the object OB updated at time t1 and the position of the object OB at time t0, the distance d1 between the target travel route R t0 is larger than the distance d0 between the position of the object OB detected at time t0 and the target travel route R t0 (d1 > d0). In this case, similar to the situation at time t0, when the ECU 10 sets a new target travel route based on the road travel information and the position of the object OB updated at time t1, the next target travel route R' t0 is closer to the object OB than the target travel route R t1This will be set (shown by the dashed line in Figure 3(c)). In this case, the target travel path R' t1 The system is set to move forward while turning to the left so that vehicle 1 approaches object OB. In other words, vehicle 1, which had started turning to the right between time t0 and t1, is then made to turn to the left again, resulting in frequent changes in the behavior of vehicle 1, which may be bothersome to the occupants.

[0038] Therefore, the ECU 10 in this embodiment sets the target travel path R based on the position of object OB at time t0. t0 This makes it less likely for the next target driving path to be set in an area closer to object OB. As a result, in the example in Figure 3(c), the ECU 10 sets the target driving path R based on the position of object OB at time t0. t0 A new target driving path R that causes vehicle 1 to travel to the same position as before. t1 Set the (shown by the dotted line in Figure 3(c)) as shown.

[0039] [Basic Concepts of Setting Target Driving Routes] Next, with reference to Figure 4, the basic concept of target driving path setting performed by the ECU 10 described above in this embodiment will be explained. Figure 4 shows vehicle 1 driving on the driving path 6.

[0040] First, the ECU 10 performs calculations to determine the vehicle's position on the road 6 based on the road information. The road information is information about the road 6 on which the vehicle 1 is traveling, and is acquired by cameras 21, radar 22, navigation system 30, etc. The road information includes, for example, information about the shape of the road (straight, curve, curve curvature), road width, number of lanes, lane width, etc.

[0041] Next, the ECU 10 calculates based on the road information and places multiple virtual grid points G on the road 6 located in front of the vehicle 1 in the direction of travel. n Set (n=1,2,···N). Define the direction in which the road 6 extends as the x-direction, and the width direction of the road 6 as the y-direction, then grid point G nThese are arranged in a grid pattern along the x and y directions. The origin of the x and y coordinates is set to the point corresponding to the position of vehicle 1.

[0042] ECU10 is at grid point G n The range for setting the grid points G extends along the travel path 6, over a distance L in front of the vehicle 1. The distance L is calculated based on the speed of the vehicle 1 at the time of calculation. In this embodiment, the distance L is the distance that the vehicle is expected to travel in a predetermined fixed time t (e.g., 3 seconds) at the speed (V) at the time of calculation (L = V × t). However, the distance L may be a predetermined fixed distance (e.g., 100 m) or may be a function of speed (and acceleration). Also, grid point G n The width W of the range in which the grid points G are set is set to a value approximately equal to the width of the travel path 6. n This setting makes it possible to determine the position on the travel path 6.

[0043] Note that the track 6 shown in Figure 4 is a straight section, therefore grid point G n They are arranged in a rectangular shape. However, grid point G n Since the grid points are positioned along the direction in which the track extends, if the track includes a curved section, then grid point G n It is positioned along the curve of the curved section.

[0044] Next, the ECU 10 performs calculations to set candidate driving paths RC (i.e., candidate target driving paths that vehicle 1 can actually travel) based on the driving path information. For example, the ECU 10 sets multiple candidate driving path RC by using the state lattice method for path searching. According to the state lattice method, grid points G located in the direction of travel of vehicle 1 from the position of vehicle 1. n Multiple candidate driving path RCs are set up so that they branch out toward the same direction. Figure 4 shows some of the candidate driving path RCs set by the ECU 10. a RC b RC c This indicates that.

[0045] In addition to the road information, the ECU 10 may also set candidate road paths RC based on obstacle information. This obstacle information includes information about the presence or absence of obstacles (e.g., preceding vehicles, parked vehicles, pedestrians, fallen objects, etc.) on the road 6 in the direction of travel of the vehicle 1, as well as their direction of movement and speed of movement, and is acquired by the camera 21 and radar 22.

[0046] Next, as shown in Figure 4, the ECU 10 sets up multiple sampling points SP along each candidate travel route RC and calculates the route cost at each sampling point SP. These sampling points SP are discrete points (locations) on the route of each candidate travel route RC for which the route cost is calculated. Specifically, the ECU 10 calculates the route cost for each of the multiple sampling points SP for each of the multiple candidate travel route RCs.

[0047] Next, based on the route costs of the multiple candidate driving routes RC calculated in this way, the ECU 10 selects the route with the minimum route cost from among the multiple candidate driving routes RC and sets this route as the target driving route. Then, the ECU 10 sends control signals to at least one of the PCM 31, DSC 32, and EPS 33 so that vehicle 1 travels along the set target driving route.

[0048] [Calculating route costs] Next, the path cost according to an embodiment of the present invention will be described. Basically, the path cost includes costs that are determined according to multiple factors such as speed, longitudinal acceleration, lateral acceleration, rate of change of path, and obstacles. In this embodiment, as one of these multiple path costs, the path cost is basically determined according to the position on the road 6 (specifically, the position of the sampling point SP on the candidate road RC) so that the vehicle 1 travels in a position close to the center line of its own lane (the lane in which the vehicle 1 travels on the road 6) while ensuring a safe distance from obstacles. The path cost will be described in detail below.

[0049] The route cost according to this embodiment will be explained in detail with reference to Figures 5 to 8.

[0050] First, Figure 5 is a map that defines the route cost (in-lane position cost C1) according to the distance from the center line. In Figure 5, the horizontal axis represents the distance from the center line of the vehicle's lane, specifically the distance between the sampling point SP on the candidate driving path RC and the center line, and the vertical axis represents the in-lane position cost C1 (the route cost to be set for each sampling point SP) according to this distance from the center line. Also, in Figure 5, "W1" represents the width of the vehicle's lane. That is, the distance from the center line of the vehicle's lane to the end in the width direction is "W1 / 2". The ECU 10 refers to the map shown in Figure 5 and determines the in-lane position cost C1 according to the distance between the sampling point SP and the center line for which the route cost should be calculated.

[0051] As shown in Figure 5, in this embodiment, the in-lane position cost C1 of the sampling point SP is basically lowered as the distance between the center line and the sampling point SP decreases, and the in-lane position cost C1 of the sampling point SP is increased as the distance between the center line and the sampling point SP increases. This makes it possible to set a driving path in which the vehicle 1 travels in a position close to the center line of its own lane.

[0052] Furthermore, in this embodiment, when the distance between the center line and the sampling point SP is less than "W1 / 2", the rate of change of the in-lane position cost C1 with respect to the distance between the center line and the sampling point SP is made larger than when the distance between the center line and the sampling point SP is "W1 / 2" or greater. That is, when the sampling point SP is within the vehicle's lane, the rate of change of the in-lane position cost C1 is made larger than when the sampling point SP is within the vehicle's lane. By doing this, when the sampling point SP is within the vehicle's lane, the influence of the in-lane position cost C1 related to lane centering on route selection is increased, and when the sampling point SP is outside the vehicle's lane, the influence of the in-lane position cost C1 related to lane centering on route selection is reduced.

[0053] Figure 6 is a map that defines the path cost (obstacle location cost C2) according to the distance from the position of an object OB (obstacle) in front of vehicle 1. In Figure 6, the horizontal axis represents the distance from the obstacle, specifically the distance between the sampling point SP on the candidate driving path RC and the detection position of object OB, and the vertical axis represents the obstacle location cost C2 (path cost to be set for each sampling point SP) according to the distance from the position of object OB. Also in Figure 6, "SD" represents the safety distance that should be maintained between object OB and vehicle 1 in the width direction of the vehicle lane. The ECU 10 refers to the map shown in Figure 6 and determines the obstacle location cost C2 according to the distance between the sampling point SP and the position of object OB for which the path cost should be calculated.

[0054] As shown in Figure 6, in this embodiment, if the distance from the object OB is less than or equal to SD, the obstacle position cost C2 is set to a predetermined maximum value MAX. This maximum value MAX is set in advance to be significantly higher (for example, two orders of magnitude higher) than the route cost of the target travel path that is ultimately set. As a result, if the distance between the sampling point SP included in the candidate travel path RC and the object OB is less than or equal to SD, the route cost will always be higher than that of other candidate travel path RCs, and the candidate travel path RC containing that sampling point SP will not be selected as the target travel path. In other words, a distance of SD is ensured between the target travel path and the object OB.

[0055] Furthermore, if the distance from the object OB is greater than SD, the obstacle position cost C2 at the sampling point SP is increased as the distance between the object OB and the sampling point SP decreases, and decreased as the distance between the object OB and the sampling point SP increases. This allows for the setting of a driving path in which vehicle 1 travels at a distance from the object OB.

[0056] Figure 7 is a map that defines the additional route cost (additional cost C3) to be added according to the distance from the set target route when the distance between the updated position of object OB at a certain time and the target route set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target route. In Figure 7, the horizontal axis shows the distance from the set target route, specifically the distance between the sampling point SP on the candidate route RC and the set target route. The center of the horizontal axis is the origin, with the left side being closer to object OB than the target route (obstacle side) and the right side being further from object OB than the target route (anti-obstacle side). The vertical axis shows the additional cost C3 (route cost to be added for each sampling point SP) according to the distance from the set target route. The ECU 10 refers to a map like the one shown in Figure 7 to determine the additional cost C3 for each sampling point SP for which the route cost should be calculated, according to the distance between the sampling point SP and the set target route.

[0057] As shown in Figure 7, in this embodiment, the additional cost C3 is set to the maximum value MAX on the side closer to object OB (obstacle side) than the set target travel path. As a result, if the distance between the updated position of object OB at a certain time and the target travel path set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target travel path, the route cost of the candidate travel path RC in the region closer to object OB than the set target travel path will always be higher than the route cost of the candidate travel path RC that passes through the set target travel path and the candidate travel path RC in the region further from object OB. In other words, the region closer to object OB than the set target travel path is excluded from the region for which the next target travel path is set.

[0058] Furthermore, the additional cost C3 on the side closer to the object OB (obstacle side) than the set target driving path may be set to a value smaller than the maximum value MAX, and although it has a similar number of orders of magnitude to the lane position cost C1 and obstacle position cost C2 mentioned above, it may be set to a value larger than these costs C1 and C2. In this way, if the distance between the updated position of the object OB at a certain time and the target driving path set based on the position of the object OB before the update is greater than the distance between the position of the object OB before the update and the set target driving path, the path cost of the candidate driving path RC in the area closer to the object OB than the set target driving path is likely to be higher than the path cost of the candidate driving path RC that passes through the set target driving path and the candidate driving path RC in the area further from the object OB. In other words, it becomes less likely that the next target driving path will be set in an area closer to the object OB than the set target driving path.

[0059] Furthermore, on the side further from the object OB (the side opposite the obstacle) than the set target travel path, the additional cost C3 is increased as the distance between the set target travel path and the sampling point SP increases, and the additional cost C3 of the sampling point SP is decreased as the distance between the object OB and the sampling point SP decreases. In this way, the next target travel path is set at a position close to the set target travel path.

[0060] Figure 8 is a map showing an example of the route cost calculated using the lane position cost C1, obstacle position cost C2, and additional cost C3 described above, when the distance between the updated position of object OB at a certain time and the target driving path set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target driving path. In Figure 8, the horizontal axis shows the distance from the center line of the vehicle's lane, specifically the distance between the sampling point SP on the candidate driving path RC and the center line, and the vertical axis shows the route cost set for the sampling point SP. Also in Figure 8, "W1" indicates the width of the vehicle's lane, and P SD In the example in Figure 8, the position where the distance from the position of object OB is SD is P TIn the example in Figure 8, this shows the position of the target travel path set based on the position of object OB before the update.

[0061] The dashed line in Figure 8 shows the case where the route cost is calculated without adding the additional cost C3. If the updated position of object OB is farther from the target travel path set based on the position of object OB before the update, and the route cost is calculated by adding the lane position cost C1 and the obstacle position cost C2 without adding the additional cost C3, then, as shown by the dashed line in Figure 8, the position Pm where the route cost is minimized is the position P on the set target travel path. T This position is closer to object OB and also closer to the center line. This is because, as the position of object OB moves away from the set target driving path toward the center line, the obstacle position cost C2 on the center line side of the target driving path decreases, and the position where the sum of the lane position cost C1 and the obstacle position cost C2 is minimized moves toward the center line. Therefore, if the candidate driving path RC that minimizes the calculated path cost without adding the additional cost C3 is set as the next target driving path, the next target driving path will be set in an area closer to object OB than the target driving path set based on the position of object OB before the update. In this case, the target driving path R' is shown by the dashed line in Figure 3(c). t1 As a result, the behavior of vehicle 1 changes frequently, causing annoyance to the occupants.

[0062] On the other hand, the solid line in Figure 8 shows the case where the route cost is calculated by adding the additional cost C3 according to this embodiment. In this case, the position P of the set target travel route is T On the side closer to object OB (the obstacle side), the additional cost C3 is set to its maximum value MAX, so as shown by the solid line in Figure 8, the position P of the set target travel path T The path cost on the side closer to object OB will be the maximum value MAX. Therefore, the position P of the set target travel path will be the maximum value MAX. TIn areas closer to object OB, the next target travel path will not be set. Also, the position P of the set target travel path will not be set. T In areas where the distance from the center line is greater than the distance from the center line, the path cost increases with increasing distance from the center line. This is because the in-lane position cost C1 and additional cost C3 increase with increasing distance from the center line, and the rate of change is greater than the rate of change when the obstacle position cost C2 decreases with increasing distance from the center line. As a result, the next target driving path is the position P of the target driving path set based on the position of object OB before the update. T It is set to the same position as the target driving path R shown by the dotted line in Figure 3(c). t1 As shown above, a new target driving path is set so that vehicle 1 travels to the same location as the target driving path that was set based on the position of object OB before the update.

[0063] [Vehicle control processing] Next, with reference to Figure 9, the flow of the vehicle control process in this embodiment will be described. Figure 9 is a flowchart of the vehicle control process. This process is repeatedly executed by the ECU 10 at a predetermined interval (for example, every 0.05 to 0.2 seconds).

[0064] First, the ECU 10 acquires road information from the camera 21, radar 22, and navigation system 30 (step S1).

[0065] Next, the ECU 10 uses the camera 21 and radar 22 to detect the position of object OB in front of the vehicle 1, and updates the position of any object OB that has already been detected (step S2).

[0066] Next, the ECU 10 determines whether or not there is a target driving path already set on the current driving path (step S3). If there is a target driving path already set (step S3: Yes), the ECU 10 determines whether the distance between the updated position of object OB in step S2 and the target driving path set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target driving path.

[0067] As a result, if the distance between the updated object OB position and the target travel path set based on the object OB position before the update is greater than the distance between the object OB position before the update and the set target travel path (Step S4: Yes), the ECU 10 sets multiple candidate travel path RCs based on the travel path information (Step S5). For example, the ECU 10 sets multiple candidate travel path RCs by using a state lattice method for path searching and sets multiple sampling points SP along each candidate travel path RC.

[0068] Next, the ECU 10 calculates the route cost for each of the multiple candidate driving routes RC (step S6). Specifically, for each of the multiple candidate driving routes RC, the ECU 10 calculates the route cost for each of the multiple sampling points SP. At this time, the ECU 10 calculates the route cost using the lane position cost C1 and the obstacle position cost C2, along with the additional cost C3. For example, the ECU 10 calculates the sum of the lane position cost C1, the obstacle position cost C2, and the additional cost C3 for each of the multiple sampling points SP. Then, the ECU 10 calculates the route cost to apply to a candidate driving route RC from the multiple route costs calculated for the multiple sampling points SP of that candidate driving route RC. For example, the ECU 10 takes the average of the multiple route costs at the multiple sampling points SP as the route cost for a candidate driving route RC. In this way, the ECU 10 calculates the route cost for all of the multiple candidate driving route RCs.

[0069] Next, the ECU 10 sets the target driving route (step S7). Specifically, based on the route costs of each of the multiple candidate driving route RCs calculated as described above, the ECU 10 selects the one route with the minimum route cost from among the multiple candidate driving route RCs and sets this route as the target driving route.

[0070] Furthermore, in the determination in step S3, if there is no target driving path already set (step S3: No), or in the determination in step S4, if the distance between the updated object OB position and the target driving path set based on the object OB position before the update is less than or equal to the distance between the object OB position before the update and the set target driving path (step S4: No), the ECU 10 sets multiple candidate driving path RCs based on the driving path information (step S8). For example, similar to the case in step S5, the ECU 10 sets multiple candidate driving path RCs by path search using the state lattice method and sets multiple sampling points SP along each candidate driving path RC.

[0071] Next, the ECU 10 calculates the route cost for each of the multiple candidate driving routes RC (step S9). Specifically, for each of the multiple candidate driving routes RC, the ECU 10 calculates the route cost for each of the multiple sampling points SP. At this time, the ECU 10 calculates the route cost using the lane position cost C1 and the obstacle position cost C2, without using the additional cost C3. For example, the ECU 10 calculates the sum of the lane position cost C1 and the obstacle position cost C2 for each of the multiple sampling points SP. Then, the ECU 10 calculates the route cost to apply to a candidate driving route RC from the multiple route costs calculated for the multiple sampling points SP of that candidate driving route RC. For example, the ECU 10 takes the average of the multiple route costs at the multiple sampling points SP as the route cost for one candidate driving route RC. In this way, the ECU 10 calculates the route cost for all of the multiple candidate driving route RC. Next, the ECU 10 sets the target driving route (step S7).

[0072] After setting the target driving path in step S7, the ECU 10 performs driving control, including speed control and / or steering control of the vehicle 1, so that the vehicle 1 travels along the target driving path (step S10). Specifically, the ECU 10 sends control signals to at least one of the PCM 31, DSC 32, and EPS 33 to control at least one of the power source 2, transmission 3, brakes 4, and steering device 5. Then, the ECU 10 returns to step S1 and repeats the processes from steps S1 to S10.

[0073] In the embodiments described above, the case in which the ECU 10 sets the target driving route by pathfinding using the state lattice method was explained as an example. However, the present invention can also be applied to cases in which the target driving route is set using other known driving route generation algorithms, such as the A-STER method or Dijkstra's algorithm.

[0074] [Mechanism of Action and Effects] Next, the effects and advantages of the vehicle control device 100 of this embodiment described above will be explained.

[0075] If the distance between the updated position of object OB (Obstruction Obstruction) by camera 21 or radar 22 and the target driving path set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target driving path, the ECU 10 makes it difficult to set the next target driving path in an area closer to object OB than the set target driving path. This suppresses the setting of a target driving path that approaches the updated position of object OB when the position of object OB is updated in a direction away from the set target driving path. As a result, frequent changes in vehicle behavior due to changes in the target driving path can be suppressed, ensuring a safe distance between vehicle 1 and obstacles while preventing occupants from feeling inconvenienced.

[0076] Alternatively, if the distance between the updated position of object OB by camera 21 or radar 22 and the target driving path set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target driving path, the ECU 10 excludes the area closer to object OB than the set target driving path from the area where the next target driving path is set. Therefore, if the position of object OB is updated in a direction away from the set target driving path, a target driving path that approaches the updated position of object OB will not be set. This prevents frequent changes in vehicle behavior due to changes in the target driving path, ensuring a safe distance between the vehicle 1 and obstacles while preventing occupants from feeling inconvenienced.

[0077] Furthermore, if the distance between the updated position of object OB by camera 21 or radar 22 and the target driving path set based on the position of object OB before the update is greater than the distance between the position of object OB before the update and the set target driving path, the ECU 10 sets the path cost of a candidate driving path RC that passes through an area closer to object OB than the set target driving path to be higher than the path cost of a candidate driving path RC that passes through the set target driving path. Therefore, if the position of object OB is updated in a direction away from the set target driving path, it becomes difficult, or even impossible, to set a candidate driving path RC that approaches the updated position of object OB as the next target driving path. This prevents frequent changes in vehicle behavior due to changes in the target driving path, ensuring a safe distance between the vehicle 1 and obstacles while preventing occupants from feeling inconvenienced. [Explanation of symbols]

[0078] 1 vehicle 6. Driving Route 10 ECU 21 Cameras 22 Radar 30 Navigation System 100 Vehicle control device OB object R Target driving route RC driving route candidates

Claims

1. A vehicle travel information acquisition device that acquires travel information about the vehicle's travel path, An object detection device that detects the position of an object in front of the vehicle and repeatedly updates that position, A controller configured to repeatedly set a target driving path on the driving path based on the driving path information and the position of the object, and to control the vehicle so that the vehicle drives along the target driving path, The controller is configured such that, if the distance between the updated position of the object detected by the object detection device and the target travel path set based on the object's position before the update is greater than the distance between the object's position before the update and the set target travel path, it becomes difficult to set the next target travel path in an area closer to the object than the set target travel path. Vehicle control system.

2. A vehicle travel information acquisition device that acquires travel information about the vehicle's travel path, An object detection device that detects the position of an object in front of the vehicle and repeatedly updates that position, A controller configured to repeatedly set a target driving path on the driving path based on the driving path information and the position of the object, and to control the vehicle so that the vehicle drives along the target driving path, The controller is configured such that, if the distance between the updated position of the object detected by the object detection device and the target travel path set based on the object's position before the update is greater than the distance between the object's position before the update and the set target travel path, it excludes the area closer to the object than the set target travel path from the area where the next target travel path is set. Vehicle control system.

3. The aforementioned controller, Based on the aforementioned route information, a plurality of candidate routes are set to determine the target route. Based on the aforementioned road information and the position of the object in front of the vehicle, the route cost is calculated for each of the plurality of candidate routes. The smaller the distance between the object's position and the candidate travel path, the higher the route cost of the candidate travel path. The greater the distance between the center line of the vehicle's lane on the aforementioned road and the candidate travel route, the higher the route cost of the candidate travel route. Among the multiple candidate routes, the route with the lowest route cost is set as the target route. If the distance between the updated position of the object detected by the object detection device and the target travel path set based on the object's position before the update is greater than the distance between the object's position before the update and the set target travel path, the system is configured to set the route cost of a candidate travel path that passes through an area closer to the object than the set target travel path to be higher than the route cost of a candidate travel path that passes through the set target travel path. The vehicle control device according to claim 1 or 2.

4. A vehicle control method performed by a control device equipped with a computer, Steps include obtaining road information regarding the vehicle's travel path, The steps include detecting the position of an object in front of the vehicle and repeatedly updating that position, The steps include repeatedly setting a target driving path on the driving path based on the driving path information and the position of the object, The process includes the step of controlling the vehicle so that it travels along the target travel path, The step of setting the target travel path includes, if the distance between the updated position of the object in the step of repeatedly updating the position of the object and the target travel path set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target travel path, a step that makes it difficult to set the next target travel path in an area closer to the object than the set target travel path. Vehicle control method.

5. A vehicle control method performed by a control device equipped with a computer, Steps include obtaining road information regarding the vehicle's travel path, The steps include detecting the position of an object in front of the vehicle and repeatedly updating that position, The steps include repeatedly setting a target driving path on the driving path based on the driving path information and the position of the object, The process includes the step of controlling the vehicle so that it travels along the target travel path, The step of setting the target travel path includes, if the distance between the updated position of the object in the step of repeatedly updating the position of the object and the target travel path set based on the position of the object before the update is greater than the distance between the position of the object before the update and the set target travel path, the step of excluding the area closer to the object than the set target travel path from the area where the next target travel path is set. Vehicle control method.

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