Vehicle control device, vehicle control method, and vehicle control system

Abstract

In this aspect, the vehicle control device, vehicle control method, and vehicle control system according to the present invention acquire information related to a difference of position in the left–right direction between a target path and an actual path of a vehicle, use information related to the difference of position in the left–right direction to estimate a disturbance corresponding to the difference of position in the left–right direction, and use the disturbance to obtain a control command for causing the vehicle to follow the target path. With this arrangement, the disturbance can be estimated accurately and the ability to follow the target path can be increased.

Description

[Technical field]

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a vehicle control system. [Background technology]

[0002] Patent Document 1 discloses a cant estimation method for estimating the cant of a road on which a vehicle is traveling. This cant estimation method includes the steps of acquiring vehicle information including information on speed, lateral acceleration, steering angle, yaw rate and position of a plurality of vehicles including a first vehicle, estimating a cant of a road on which the first vehicle is traveling based on the vehicle information, and storing the estimated cant in a cant angle database available to the plurality of vehicles in association with information on the position of the first vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-172220 A Summary of the Invention [Problem to be solved by the invention]

[0004] In autonomous driving, in which the vehicle's actual trajectory follows a target trajectory, for example, when the vehicle travels on a road with a left-right gradient (in other words, a transverse gradient), gravity can cause the actual trajectory to shift toward the lower gradient, reducing the ability of the actual trajectory to track the target trajectory. In addition, crosswinds can also apply external forces to the vehicle that deflect the vehicle, causing the actual trajectory to deviate from the target trajectory, and vehicle characteristics such as alignment that contribute to the deflection of the vehicle 10 can also cause the actual trajectory to deviate from the target trajectory.

[0005] Here, in order to prevent a decrease in tracking to the target trajectory due to disturbances such as the lateral gradient of the road or crosswinds, it is necessary to estimate the amount of disturbance with high accuracy and to make control commands such as steering control commands commensurate with the amount of disturbance. However, in a process of estimating the amount of disturbance based on information related to vehicle movement such as vehicle speed, lateral acceleration, and yaw rate, it is difficult to estimate the amount of disturbance with high accuracy, and even if a vehicle control device controls the vehicle based on the results of estimating the amount of disturbance, it is not possible to sufficiently prevent the trackability of the actual trajectory relative to the target trajectory from being reduced due to disturbances.

[0006] The present invention has been made in consideration of the conventional situation, and an object of the present invention is to provide a vehicle control device, a vehicle control method, and a vehicle control system that can accurately estimate a disturbance amount and improve tracking to a target trajectory. [Means for solving the problem]

[0007] According to one aspect of the present invention, information regarding a difference in lateral position between a target trajectory of a vehicle and an actual trajectory of the vehicle is acquired, and a disturbance amount corresponding to the difference in lateral position is estimated using the information regarding the difference in lateral position, and a control command for causing the vehicle to follow the target trajectory is obtained using the disturbance amount. The amount of disturbance is estimated using information regarding the past difference in position in the left-right direction and information regarding the current difference in position in the left-right direction. In addition, according to the present invention, in another aspect, the present invention is configured to obtain information regarding the difference in lateral position between a target trajectory of a vehicle and an actual trajectory of the vehicle, estimate an amount of disturbance equivalent to the difference in lateral position using the information regarding the difference in lateral position, and use the amount of disturbance to obtain a control command for causing the vehicle to follow the target trajectory, wherein a control command for the lateral acceleration of the vehicle is obtained as the control command so as to reduce the difference in lateral position, and the control command for the lateral acceleration is obtained so as to compensate for the difference between the lateral gradient of the road surface on the target trajectory and the lateral gradient of the road surface on the actual trajectory. Effect of the Invention

[0008] According to the present invention, the amount of disturbance can be estimated with high accuracy, and the ability to follow the target trajectory can be improved. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a first embodiment of a vehicle control system. [Diagram 2] FIG. 4 is a diagram showing one aspect of various variables and a coordinate system used in calculating a lateral acceleration command; [Diagram 3] FIG. 13 is a diagram showing the left-right deviation as a straight-line distance. [Figure 4] FIG. 13 illustrates the lateral deviation as a length along the road surface. [Diagram 5] FIG. 13 is a diagram showing a state in which a lateral deviation occurs due to a lateral gradient. [Figure 6] 13 is a time chart illustrating changes in a lateral deviation and a lateral gradient estimated value, showing a state in which the change in the lateral gradient estimated value is not limited; [Figure 7] 13 is a time chart illustrating an example of changes in a lateral deviation and a lateral gradient estimated value, showing a state in which the change in the lateral gradient estimated value is limited; [Figure 8] FIG. 4 is a block diagram showing a second embodiment of a vehicle control system. [Figure 9] FIG. 11 is a block diagram showing a third embodiment of a vehicle control system. [Figure 10] 5A and 5B are diagrams for explaining a process of estimating a lateral gradient based on a yaw rate, a vehicle speed, and a lateral acceleration. [Figure 11] FIG. 2 is a block diagram showing a system for performing steering control and braking force control in response to a lateral acceleration command. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a vehicle control device, a vehicle control method, and a vehicle control system according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a vehicle control system 100. As shown in FIG.

[0011] The vehicle control system 100 is mounted on a vehicle 10 such as a four-wheeled automobile. Then, the vehicle control system 100 controls the steering angle by the electronically controlled power steering device 600 so that the vehicle 10 follows a target trajectory (in other words, a target path) during automatic driving.

[0012] The vehicle control system 100 includes a vehicle state detection device 200, an external environment recognition device 300, an automatic driving control device 400, a vehicle motion control device 500, an electronically controlled power steering device 600, and an ESC (Electric Stability Control) unit 700. The automatic driving control device 400, the vehicle motion control device 500, and the ESC unit 700 are electronic control devices mainly including microcomputers 400A, 500A, and 700A that perform calculations based on input information and output the results of the calculations.

[0013] The microcomputers 400A, 500A, and 700A each include a microprocessor unit (MPU), a read only memory (ROM), a random access memory (RAM), and the like. The microcomputer 400A of the automatic driving control device 400 has a function of a trajectory generating unit 410 that calculates a target trajectory.

[0014] The trajectory generation unit 410 uses the vehicle state detection device 200 and the external environment recognition device 300 to acquire position information of the vehicle 10 (in other words, information on the vehicle's position), vehicle driving state information, and surrounding information, and calculates a target trajectory based on the acquired information. Then, the microcomputer 500A of the vehicle motion control device 500 calculates a steering control command, more specifically, a steering angle control command or a steering torque control command, for causing the vehicle 10 to follow the target trajectory calculated by the automatic driving control device 400, and outputs the calculated steering control command to the electronic control power steering device 600.

[0015] The electronically controlled power steering device 600 is a steering device that changes the angle of the front wheels 11L, 11R of the vehicle 10 to change the traveling direction of the vehicle 10. The electronically controlled power steering device 600 includes a steering actuator 601 such as a motor that changes the angle of the front wheels 11L, 11R, which are steered wheels, and a steering control unit 602 that is an actuator control device that controls the steering actuator 601.

[0016] The steering control unit 602 controls the steering actuator 601 based on a steering control command obtained from the vehicle motion control device 500, and realizes a steering angle or steering torque according to the steering control command. In other words, in the vehicle control system 100, the automatic driving control device 400 generates a target trajectory for the vehicle 10, the vehicle motion control device 500 obtains control commands for causing the vehicle 10 to follow the target trajectory, and the steering control unit 602 acquires the control commands and controls the steering actuator 601.

[0017] The vehicle condition detection device 200 includes a wheel speed / vehicle speed sensor 210 that detects the wheel speed or vehicle speed, a yaw rate sensor 220 that detects the yaw rate of the vehicle 10, a lateral G sensor 230 that detects the lateral acceleration of the vehicle 10, and a steering angle sensor 240 that detects the steering angle of the front wheels 11L, 11R. The external environment recognition device 300 also includes a stereo camera 310, a navigation system 320, an inter-vehicle communication device 330, a radar 340, and an omnidirectional camera 350.

[0018] The stereo camera 310 detects and identifies objects around the vehicle 10, and determines the distance to the objects, etc. That is, the stereo camera 310 measures the parallax from the difference in how the left and right cameras see things, and calculates the distance to the object using the principles of triangulation.

[0019] The navigation system 320 includes a GPS (Global Positioning System) receiver and a map database, and acquires information on the current position of the vehicle 10, information on the route to the destination, and the like. The GPS receiver of the navigation system 320 measures the latitude and longitude of the position of the vehicle 10 by receiving signals from GPS satellites.

[0020] The map database of the navigation system 320 is a database formed in a storage device mounted on the vehicle 10, and the map information includes information on road positions, road shapes, intersection positions, and the like. The inter-vehicle communication device 330 obtains road traffic information, behavior information of other vehicles, position information of other vehicles, and the like from other vehicles through wireless communication between vehicles.

[0021] The radar 340 detects an obstacle ahead of the vehicle 10, and further measures the distance to the obstacle ahead and the speed of the obstacle ahead, and outputs the information relating to the obstacle ahead. The omnidirectional camera 350 is a device that converts the viewpoint of images obtained from multiple cameras mounted on the front, rear, left and right sides of the vehicle 10, and obtains an image as if the vehicle were being looked down on from above, that is, an overhead image.

[0022] The automatic driving control device 400 recognizes the situation around the vehicle based on the vehicle position and information on objects around the vehicle obtained from the external environment recognition device 300, and generates a target trajectory, which is the goal of the driving route of the vehicle 10, based on the recognition result. Here, the automatic driving control device 400 acquires the position information of the vehicle 10 based on the results of recognition of the surrounding conditions by GPS positioning, dead reckoning, stereo camera 310, etc., and also based on information obtained from other vehicles traveling in the vicinity via vehicle-to-vehicle communication.

[0023] A method of acquiring position information of the vehicle 10 using positioning by dead reckoning or the results of recognition of the surrounding conditions by the stereo camera 310 or the like is a method of acquiring information regarding the position of the vehicle 10 based on signals from on-board sensors. In dead reckoning, the position of the vehicle 10 is estimated based on, for example, the vehicle speed and yaw angle of the vehicle 10.

[0024] On the other hand, a method of acquiring location information of the vehicle 10 based on GPS positioning or information obtained from other vehicles traveling nearby via vehicle-to-vehicle communication is a method of acquiring information regarding the location of the vehicle 10 based on a signal received from outside the vehicle 10. In GPS positioning, the signals received from outside the vehicle 10 are signals received from GPS satellites, specifically, time data, satellite orbit information, and the like. In addition, in positioning using vehicle-to-vehicle communication, the signal received from outside the vehicle 10 is a signal received from another vehicle via vehicle-to-vehicle communication.

[0025] When the ESC unit 700 detects a slipping behavior of the vehicle 10, it performs control to keep the posture of the vehicle 10 stable by controlling the output of the drive system of the vehicle 10 and / or the brake pressure of each wheel in the braking system of the vehicle 10. The ESC unit 700 acquires information such as the vehicle speed, lateral acceleration, steering angle, and yaw rate of the vehicle 10 from the vehicle state detection device 200, and monitors the driver's driving operation and the movement of the vehicle 10 based on the acquired vehicle information. Then, the ESC unit 700 activates a function for keeping the posture of the vehicle 10 stable based on the driver's driving operation and the movement of the vehicle 10. Furthermore, the ESC unit 700 estimates the lateral gradient of the road on which the vehicle 10 is traveling based on the acquired vehicle information, and outputs information on the estimated lateral gradient to the vehicle motion control device 500.

[0026] The vehicle motion control device 500 includes a vehicle model 510 , a control unit 520 , a look-ahead compensation unit 530 , a gradient correction value creation unit 540 , a gradient correction unit 550 , a control amount correction value creation unit 560 , and an actuator control unit 570 . Here, the vehicle model 510, the control unit 520, and the look-ahead compensation unit 530 constitute a tracking control unit 501 that determines a control command for making the vehicle 10 track the target trajectory.

[0027] The following control unit 501 calculates a lateral acceleration command, which is a control command for making the vehicle 10 follow the target trajectory generated by the automatic driving control device 400, by using model predictive control. Model predictive control is a known control method that predicts future behavior using a model of a controlled object and determines the manipulated variable of the controlled object while solving an optimization problem at each time.

[0028] In the model predictive control in the vehicle motion control device 500 (more specifically, the tracking control unit 501), a vehicle model 510 is used to predict a response after a predetermined prediction time (for example, 500 ms), and a lateral acceleration command yd2c (in other words, a target value of the lateral acceleration) that reduces the tracking error in the prediction interval is searched for. By utilizing such model predictive control, it is possible to prevent a decrease in the ability of the vehicle 10 to track the target trajectory due to factors such as a delayed response of the steering actuator 601 of the electronically controlled power steering device 600, and also to realize natural trajectory control through feedforward control.

[0029] The vehicle motion control device 500 acquires information on the difference in left-right position (hereinafter referred to as "left-right deviation"), which is the distance between the vehicle 10 (in other words, the actual trajectory of the vehicle 10) and the target trajectory, the orientation of the vehicle 10 (in other words, the traveling direction of the vehicle 10 relative to the target trajectory), and the curvature of the target trajectory. Then, the vehicle motion control device 500 calculates the lateral acceleration command yd2c based on the left-right deviation (in other words, the lateral position deviation), the direction of the vehicle 10, and the curvature of the target trajectory so as to reduce the left-right deviation. In other words, the vehicle motion control device 500 has a function as a lateral difference acquisition unit that acquires information regarding the lateral difference between the target trajectory of the vehicle 10 and the actual trajectory of the vehicle 10 .

[0030] FIG. 2 is a diagram showing one embodiment of various variables and a coordinate system used in calculating the lateral acceleration command yd2c. It should be noted that the closest point P in FIG. 2 is the position of the vehicle 10 on the target trajectory, specifically, the point closest to the center of gravity CG of the vehicle 10.

[0031] 2 is a virtual line that is parallel to the tangent direction of the target trajectory at the closest point P and passes through the center of gravity CG of the vehicle 10. A coordinate system is used in which the center of gravity CG of the vehicle 10 is the origin, the track tangent direction is the x-axis, and the direction from the center of gravity CG toward the closest point P is the y-axis.

[0032] Equation 1 is a calculation formula for the lateral acceleration command yd2c.

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[0033] The lateral deviation Δy is acquired as a different physical quantity depending on the method of measuring the vehicle position. For example, the lateral deviation Δy is acquired as a lateral deviation on an actual road surface having a lateral gradient, that is, information on a length along the road surface. Alternatively, the lateral deviation Δy is acquired as a lateral deviation on a virtual plane that is assumed to have no lateral gradient, that is, information on a straight-line distance. FIG. 3 shows the left-right deviation Δy as information on the straight-line distance, and FIG. 4 shows the left-right deviation Δy as information on the length along the road surface. 3 and 4, the direction penetrating the paper surface is the traveling direction of the vehicle 10.

[0034] For example, when the vehicle control system 100 detects the vehicle position using the GPS receiver of the navigation system 320, the vehicle position is detected using GPS coordinates of latitude and longitude, and therefore the left and right gradients of the road surface are not taken into consideration, and the left and right deviation Δy is calculated as straight-line distance information, as shown in FIG. 3. On the other hand, when the vehicle control system 100 detects the vehicle position by dead reckoning based on information on the vehicle motion, the vehicle position is estimated taking into account the influence of the road surface gradient, and therefore the lateral deviation Δy is calculated as information on the length along the road surface, as shown in FIG. 4.

[0035] Furthermore, when the vehicle control system 100 detects the vehicle position based on the results of external environment recognition by the stereo camera 310, the radar 340, the omnidirectional camera 350, etc., the external environment of the vehicle 10 actually traveling on the road surface is recognized, so that the lateral deviation Δy is obtained as information of the length along the road surface, as shown in FIG. 4. However, in a case where the information on the vehicle position calculated based on the result of the external environment recognition is corrected in accordance with the lateral gradient of the road surface, or in a case where the vehicle position is estimated by referring to map data based on the result of the external environment recognition, the lateral deviation Δy is calculated as information on the straight-line distance as shown in FIG. 3.

[0036] The actuator control unit 570 converts the lateral acceleration command yd2c acquired from the following control unit 501 into a steering control command which is a control command for the steering angle or steering torque, and outputs the steering control command to a steering control unit 602 of the electronically controlled power steering device 600. Then, the steering control unit 602 realizes the lateral acceleration command yd2c by controlling the steering actuator 601 based on the acquired steering control command.

[0037] On the other hand, the gradient correction value creation unit 540, the gradient correction unit 550, and the control amount correction value creation unit 560 estimate the amount of disturbance that deflects the trajectory of the vehicle 10 in the left-right direction using information on the left-right deviation Δy, and correct the lateral acceleration command yd2c (or the steering control command) using the estimated amount of disturbance. In other words, the vehicle motion control device 500 has the functions of a disturbance estimation unit that estimates a disturbance amount equivalent to the left-right deviation Δy using information on the left-right deviation Δy, and a tracking control unit that uses the estimated disturbance amount to obtain a control command for causing the vehicle 10 to track the target trajectory.

[0038] Here, the disturbances that cause the trajectory of the vehicle 10 to deviate left and right include external forces acting on the vehicle 10, such as the left and right gradient of the road and crosswinds, that cause the trajectory of the vehicle 10 to deviate left and right, and vehicle characteristics, such as wheel alignment, that cause the trajectory of the vehicle 10 to deviate left and right. For example, if the road has a left-right gradient, gravity may cause the actual trajectory of the vehicle 10 to deviate from the target trajectory to the side with a lower gradient, reducing the ability to follow the target trajectory. Furthermore, when a crosswind is blowing in a direction perpendicular to the traveling direction of the vehicle 10, the actual trajectory of the vehicle 10 may deviate downwind from the target trajectory due to wind pressure, reducing the ability to track the target trajectory.

[0039] FIG. 5 shows a state in which a lateral deviation Δy occurs on a road having a lateral gradient. In the case of Figure 5, the road has a lateral gradient with the right side of the vehicle 10 in the traveling direction being higher and the left side being lower, so gravity causes the trajectory of the vehicle 10 to shift to the left of the target trajectory (in other words, to the side with the lower gradient), resulting in a lateral deviation Δy.

[0040] If a lateral deviation Δy occurs due to a lateral gradient or disturbance such as wind, the lateral acceleration command yd2c calculated by the tracking control unit 501 using Equation 1 is changed in a direction that reduces the lateral deviation Δy. However, since the calculation process of the lateral acceleration command yd2c using Equation 1 is suitable for reducing the left-right deviation Δy in an undisturbed state, even if steering control is performed according to the lateral acceleration command yd2c calculated from Equation 1, there may be cases where convergence to the target trajectory is delayed or steady-state deviation occurs.

[0041] Therefore, the vehicle motion control device 500 estimates the amount of disturbance such as lateral gradient and crosswind, and corrects the lateral acceleration command yd2c (or the steering control command) calculated according to Equation 1 based on the estimated amount of disturbance, thereby preventing the tracking ability to the target trajectory from being reduced due to disturbance. Note that, when only the lateral gradient is considered, Equation 1 is an equation for deriving the lateral acceleration command yd2c on the assumption that the lateral gradient of the road surface on which the vehicle 10 runs is zero. Therefore, the vehicle motion control device 500 corrects the lateral acceleration command yd2c (or the steering control command) so as to compensate for the difference between the lateral gradient of the road surface on the target trajectory and the lateral gradient of the road surface on the actual trajectory of the vehicle 10.

[0042] In the vehicle control system 100 shown in FIG. 1, the vehicle motion control device 500 acquires information on an estimated value of the lateral gradient from the ESC unit 700. However, the estimated value of the lateral gradient has low accuracy for use in control for preventing a decrease in follow-up ability to external disturbances. Therefore, the gradient correction value generating unit 540 obtains a left / right gradient correction value ΔLRG for correcting the left / right gradient estimated value LRG1 [deg] estimated by the ESC unit 700, using the left / right deviation Δy.

[0043] Then, the gradient correction section 550 corrects the left / right gradient estimated value LRG1 estimated by the ESC unit 700 with the left / right gradient correction value ΔLRG created by the gradient correction value creation section 540 to obtain a final left / right gradient estimated value LRG. As a result, the lateral gradient estimated value LRG becomes a value that reflects with high accuracy various disturbances that cause the vehicle 10 to deflect, such as the lateral gradient, crosswind, and further vehicle characteristics. The control amount correction value creation unit 560 calculates a control amount correction value based on the left-right gradient estimated value LRG (in other words, an estimated value of the disturbance amount), and corrects the lateral acceleration command yd2c calculated according to equation 1 (or a steering control command based on the lateral acceleration command yd2c calculated according to equation 1) with the calculated control amount correction value.

[0044] For example, when vehicle 10 travels on a road with a lateral gradient, a gravitational component force is generated in the direction of the lower lateral gradient, and vehicle 10 is pulled by this component force, resulting in a lateral deviation Δy between the target trajectory and the actual trajectory. Therefore, the gradient correction value generating unit 540 calculates the lateral gradient correction value ΔLRG on the assumption that the lateral acceleration controlled based on the lateral deviation Δy and the component force of the gravitational acceleration are balanced.

[0045] If it is assumed that the lateral acceleration controlled based on the lateral deviation Δy and the component of the gravitational acceleration are balanced, then Equation 2 can be derived from Equation 1.

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[0046] Here, assuming that the left-right deviation Δy is constant and the angle θ and the curvature R are zero, Equation 2 is transformed into Equation 3.

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[0047] Therefore, if the gain G1 is 1, the left / right gradient correction value ΔLRG can be calculated from Equation 4.

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[0048] For example, if the lateral deviation Δy is 0.2 m, the lateral gradient correction value ΔLRG is ΔLRG=1.169 [deg] as shown in Equation 5.

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[0049] The gradient correction unit 550 acquires information on the left / right gradient correction value ΔLRG calculated by the gradient correction value creation unit 540 and the left / right gradient estimated value LRG1 estimated by the ESC unit 700, and calculates the final left / right gradient estimated value LRG [deg] according to Equation 6.

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[0050] For example, when the lateral deviation Δy is zero and the actual trajectory of the vehicle 10 is able to track the target trajectory, the gradient correction value creation unit 540 calculates the lateral gradient correction value ΔLRG to be 0 [deg], and the gradient correction unit 550 sets the lateral gradient estimation value LRG1 estimated by the ESC unit 700 as the final lateral gradient estimation value LRG as is. On the other hand, when the vehicle 10 is traveling on a side with a lower lateral gradient with respect to the target trajectory, the gradient correction value creation unit 540 calculates a lateral gradient correction value ΔLRG that increases the lateral gradient estimated value LRG1, and the gradient correction unit 550 sets the result of increasing the lateral gradient estimated value LRG1 estimated by the ESC unit 700 by the lateral gradient correction value ΔLRG as the final lateral gradient estimated value LRG.

[0051] Furthermore, when the vehicle 10 is traveling along a lateral gradient that is greater than the target trajectory, the gradient correction value generating unit 540 calculates a lateral gradient correction value ΔLRG that reduces and corrects the lateral gradient estimated value LRG1. The gradient correction section 550 reduces the left / right gradient estimated value LRG1 estimated by the ESC unit 700 by the left / right gradient correction value ΔLRG and sets the result as the final left / right gradient estimated value LRG. That is, the lateral deviation Δy is generated due to the influence of the estimation error of the lateral gradient estimated value LRG1 by the ESC unit 700, crosswinds, variations in vehicle characteristics, etc. Therefore, the lateral gradient estimated value LRG obtained by correcting the lateral gradient estimated value LRG1 with the lateral gradient correction value ΔLRG based on the lateral deviation Δy becomes information that represents the amount of disturbance such as the lateral gradient and the crosswind with high accuracy.

[0052] The control amount correction value creation unit 560 obtains information on the left / right gradient estimated value LRG from the gradient correction unit 550, and calculates a control amount correction value that suppresses the occurrence of the left / right deviation Δy due to the left / right gradient, based on the left / right gradient estimated value LRG. In the above-mentioned formula 1, the lateral acceleration command yd2c is calculated to reduce the lateral deviation Δy without taking into account disturbances that deflect the vehicle 10, such as lateral gradients and crosswinds, so that the tracking ability to the target trajectory decreases when a disturbance occurs.

[0053] Therefore, the control amount correction value generating unit 560 corrects the lateral acceleration command yd2c calculated according to Equation 1 in accordance with the disturbance amount (that is, the lateral gradient estimated value LRG), thereby correcting the lateral acceleration command yd2c to a value that takes the disturbance amount into account. By correcting the lateral acceleration command yd2c in accordance with the lateral gradient estimated value LRG, a decrease in the ability to follow the target trajectory is prevented even if a disturbance occurs.

[0054] In addition, when the vehicle 10 starts, a large lateral deviation Δy may be detected. If the lateral gradient correction value ΔLRG is calculated based on such lateral deviation Δy, this may reduce the ability to track the target trajectory. Therefore, when the lateral deviation Δy is greater than the upper limit, the gradient correction value preparation unit 540 sets the lateral gradient correction value ΔLRG to zero, so that the lateral acceleration command yd2c is corrected using the lateral gradient estimated value LRG1 as is.

[0055] Here, the upper limit value is set as a value that the lateral deviation Δy exceeds only when the vehicle 10 starts moving, etc. In other words, when the lateral deviation Δy is outside the predetermined range, the vehicle motion control device 500 does not estimate the disturbance amount using information on the lateral deviation Δy. Furthermore, when the vehicle 10 is traveling without using the target trajectory, the gradient correction value generating unit 540 and the gradient correcting unit 550 stop correcting the lateral gradient estimated value LRG1.

[0056] Furthermore, because the lateral gradient of a road does not change suddenly due to the road structure, the gradient correction value creation unit 540 or the gradient correction unit 550 gradually changes the lateral gradient correction value ΔLRG or the final lateral gradient estimated value LRG even when the lateral deviation Δy changes suddenly, and thus limits the rate of change of the lateral acceleration command yd2c to within a predetermined range. 6 and 7 are diagrams showing changes in the lateral gradient estimated value LRG (or the lateral gradient correction value ΔLRG) in response to a sudden change in the lateral deviation Δy. Fig. 6 shows a case in which a sudden change in the lateral deviation Δy is directly reflected in the final lateral gradient estimated value LRG. Fig. 7 shows a case in which the final lateral gradient estimated value LRG is gradually made to follow a sudden change in the lateral deviation Δy.

[0057] In the case of Fig. 6, the final lateral gradient estimate value LRG changes suddenly in response to a sudden change in the lateral deviation Δy. In contrast, in the case of Fig. 7, the amount of change in the lateral gradient estimate value LRG or the lateral gradient correction value ΔLRG per calculation cycle is limited based on an upper limit value, so that even if the lateral deviation Δy changes suddenly, the final lateral gradient estimate value LRG changes gradually. In this manner, if the final lateral gradient estimated value LRG is gradually changed even if the lateral deviation Δy changes suddenly, a sudden change in the lateral acceleration command yd2c due to a sudden change in the lateral deviation Δy is prevented, and a sudden change in the steering angle is prevented, thereby achieving smooth vehicle motion.

[0058] Furthermore, when the tracking control unit 501 performs model predictive control as described above, the gradient correction value creation unit 540 can calculate the lateral gradient correction value ΔLRG from the difference between the predicted value and the actual value of the lateral deviation Δy, in other words, the difference between the predicted value at a past point in time and the current actual value. For example, the tracking control unit 501 detects a left / right deviation Δy z-50 When estimating, the gradient correction value generating unit 540 uses the lateral deviation Δy z-50 A lateral gradient correction value ΔLRG is calculated based on the difference between the lateral deviation Δy, which is the current actual value (in other words, the prediction error).

[0059]

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[0060] Incidentally, in the vehicle control system 100 shown in FIG. 1, the vehicle motion control device 500 acquires information on the lateral gradient estimated value LRG1 estimated by the ESC unit 700, but the external electronic control device that estimates the lateral gradient is not limited to the ESC unit 700. For example, if the vehicle 10 is equipped with an active suspension, the vehicle motion control device 500 can acquire information on the left and right gradients estimated by the electronic control device of the active suspension based on the detection output of a G sensor (acceleration sensor), and correct the acquired left and right gradient estimates based on the left and right deviation Δy.

[0061] An active suspension is a device that applies hydraulic force to the suspension to control the movement of the vehicle 10. Such an active suspension generally has an acceleration sensor that detects vibrations and shaking that occur in response to unevenness of the road surface and the running state of the vehicle 10. The electronic control device for the active suspension can then estimate the lateral gradient from the detection output of the acceleration sensor.

[0062] In addition, in an image processing device for the stereo camera 310 or an automatic driving control device 400 that acquires images from the stereo camera 310, information on the left and right gradients calculated from the images from the stereo camera 310 can be acquired by a vehicle motion control device 500 as a system. Furthermore, instead of obtaining information on the left / right gradient estimation value LRG used in the tracking control by correcting information on the left / right gradient estimation value LRG1 acquired from outside based on the left / right deviation Δy, the vehicle motion control device 500 can directly determine information on the left / right gradient estimation value LRG used in the tracking control from information on the left / right deviation Δy.

[0063] FIG. 8 is a block diagram showing a second embodiment of the vehicle control system 100. A vehicle motion control device 500 shown in FIG. 8 directly calculates information on a lateral gradient estimation value LRG used for tracking control from information on the lateral deviation Δy. The vehicle motion control device 500 in FIG. 8 has a gradient estimator 580 instead of the gradient correction value generator 540 and the gradient corrector 550 in the vehicle motion control device 500 in FIG.

[0064] The gradient estimator 580 acquires information on the lateral deviation Δy, and outputs information on the lateral gradient estimated value LRG. In detail, the gradient estimator 580 directly sets the angle information calculated according to the formula 4 or the formula 7 as the left / right gradient estimated value LRG, and outputs it to the control amount correction value generator 560. Then, the control amount correction value generating unit 560 calculates a correction value for correcting the lateral acceleration command yd2c in accordance with the disturbance that causes the vehicle 10 to deflect, based on the lateral gradient estimated value LRG obtained from the gradient estimating unit 580.

[0065] In the vehicle control system 100 of FIG. 8 as well, the lateral acceleration command yd2c can be set in anticipation of disturbance amounts including lateral gradients, and a decrease in tracking ability to the target trajectory due to disturbances can be prevented. In addition, in the vehicle control system 100 of FIG. 8, the vehicle motion control device 500 does not need to acquire information about the left / right gradient estimated value LRG1 from an external source, and correction processing of the left / right gradient estimated value is also not required in the vehicle motion control device 500, so that the configuration and processing of the vehicle motion control device 500 can be simplified.

[0066] In addition, the vehicle motion control device 500 can have a function of estimating the lateral gradient from vehicle motion information such as the lateral acceleration, yaw rate, and vehicle speed of the vehicle 10, and further a function of correcting the lateral gradient estimated value based on the lateral deviation Δy. FIG. 9 is a block diagram showing a vehicle control system 100 according to a third embodiment. 9 calculates a lateral gradient estimated value LRG2 from the lateral acceleration, yaw rate, and vehicle speed, while calculating a lateral gradient correction value ΔLRG based on information on the lateral deviation Δy. The vehicle motion control device 500 then performs tracking control based on the lateral gradient estimated value LRG obtained by correcting the lateral gradient estimated value LRG2 with the lateral gradient correction value ΔLRG.

[0067] 9 is obtained by adding a gradient estimation unit 590 that estimates left and right gradients based on information about the vehicle motion state obtained from the vehicle state detection device 200 to the vehicle motion control device 500 in FIG. FIG. 10 is a diagram for explaining the process of calculating the lateral gradient estimated value LRG2 in gradient estimation section 590 based on information on the vehicle motion state, specifically, the yaw rate, the vehicle speed, and the lateral acceleration.

[0068] First, the gradient estimation unit 590 determines the centrifugal force acting on the vehicle 10 based on the detected value of the yaw rate and the detected value of the vehicle speed. Centrifugal force = yaw rate x vehicle speed

[0069] Next, gradient estimation unit 590 determines the force acting in the lateral direction on vehicle 10 based on the calculation result of centrifugal force and the detected value of lateral acceleration. Lateral force [G] = Lateral acceleration - Centrifugal force

[0070] Then, gradient estimation unit 590 obtains a left / right gradient estimated value LRG2 based on the calculation result of the force applied in the lateral direction. Left-right gradient estimate LRG2=sin -1 (Lateral force)

[0071] On the other hand, the gradient correction value generating unit 540, like the gradient correction value generating unit 540 of the vehicle control system 100 shown in FIG. 1, calculates the lateral gradient correction value ΔLRG based on the lateral deviation Δy according to Equation 4 or 7. The gradient correction unit 550 acquires the left / right gradient estimated value LRG2 calculated by the gradient estimation unit 590 and the left / right gradient correction value ΔLRG calculated by the gradient correction value creation unit 540, and sets the result of correcting the left / right gradient estimated value LRG2 with the left / right gradient correction value ΔLRG as the final left / right gradient estimated value LRG.

[0072] In other words, the vehicle motion control device 500 shown in FIG. 9 estimates the amount of disturbance that will deflect the vehicle 10 using information on the lateral acceleration of the vehicle 10, information on the yaw rate of the vehicle 10, and information on the vehicle speed of the vehicle 10, along with information on the left-right deviation Δy. In the vehicle control system 100 of FIG. 9 as well, the lateral acceleration command yd2c can be set in anticipation of disturbance amounts including lateral gradients, and a decrease in tracking ability to the target trajectory due to disturbances can be prevented.

[0073] Meanwhile, the vehicle motion control device 500 (more specifically, the actuator control unit 570) can have a function to control steering by the electronically controlled power steering device 600 as a control for making the actual trajectory of the vehicle 10 follow the target trajectory, as well as a control function to change the left / right distribution of the braking force command in the braking device (in other words, the left / right difference in braking force). FIG. 11 is a block diagram showing a vehicle control system 100 in which a vehicle motion control device 500 has a steering control function and a braking control function. An actuator control section 570 shown in FIG. 11 controls the steering by an electronically controlled power steering device 600, which is a steering device, and the braking force by a braking device 900, in order to make the actual trajectory of the vehicle 10 follow the target trajectory.

[0074] The braking device 900 is a braking device capable of individually adjusting the braking force of each wheel of the vehicle 10, and is, for example, a hydraulic braking device capable of individually adjusting the brake fluid pressure supplied to each wheel. Then, actuator control unit 570 converts lateral acceleration command yd2c into a steering control command, which is a command for steering angle or steering torque, and a brake fluid pressure command (more specifically, a left / right brake fluid pressure distribution command), and outputs the steering control command to electronically controlled power steering device 600 and outputs the brake fluid pressure command to braking device 900.

[0075] In other words, the vehicle motion control device 500 can realize the lateral acceleration command yd2c by controlling at least one of the steering by the electronically controlled power steering device 600 and the braking force by the braking device 900. For example, the vehicle motion control device 500 mainly controls steering by the electronically controlled power steering device 600 to make the actual trajectory of the vehicle 10 follow the target trajectory, and can fine-tune the deviation between the target trajectory and the actual trajectory by changing the difference in braking force between the left and right sides.

[0076] Further, the actuator control section 570 of the vehicle motion control device 500 has a function of controlling the steering by the electronically controlled power steering device 600, as well as a function of controlling the difference in driving force between the left and right wheels by the drive device of the vehicle . Actuator control section 570 can realize lateral acceleration command yd2c by controlling at least one of the steering by electronically controlled power steering device 600 and the driving force by the driving device.

[0077] Furthermore, the actuator control section 570 of the vehicle motion control device 500 can realize the lateral acceleration command yd2c by controlling the steering by the electronically controlled power steering device 600, the braking force by the braking device 900, and the driving force by the driving device. That is, the actuator control unit 570 of the vehicle motion control device 500 can realize the lateral acceleration command yd2c by controlling at least one of the steering device and the braking / driving device of the vehicle 10.

[0078] The technical ideas described in the above embodiments can be used in any suitable combination as long as no contradiction occurs. Furthermore, although the contents of the present invention have been specifically described with reference to preferred embodiments, it is obvious that a person skilled in the art can adopt various modified embodiments based on the basic technical concept and teachings of the present invention.

[0079] For example, a system may be constructed in which a single control device creates a target trajectory for the vehicle 10 and creates a control command for causing the actual trajectory of the vehicle 10 to follow the target trajectory. Furthermore, the calculation process of the lateral acceleration command yd2c in the vehicle motion control device 500 is not limited to the process using model predictive control, but may be a process that does not use model predictive control. In addition, the left-right deviation Δy can be, for example, the left-right deviation at the forward gaze point, or the distance from the vehicle 10 to the target trajectory in the left-right direction of the vehicle 10, and is not limited to the left-right deviation Δy shown in Figure 2. [Explanation of symbols]

[0080] 10...vehicle, 100...vehicle control system, 200...vehicle state detection device, 300...external environment recognition device, 400...automatic driving control device (first control device), 500...vehicle motion control device (second control device, vehicle control device), 600...electronically controlled power steering device (steering device), 602...steering control unit (actuator control device), 700...ESC unit

Claims

1. a lateral difference acquisition unit that acquires information regarding a lateral difference between a target trajectory of a vehicle and an actual trajectory of the vehicle; a disturbance estimation unit that estimates an amount of disturbance corresponding to the difference in the left-right position by using information regarding the difference in the left-right position acquired by the left-right direction difference acquisition unit; a tracking control unit that uses the disturbance amount estimated by the disturbance estimation unit to obtain a control command for causing the vehicle to track the target trajectory; Equipped with The disturbance estimation unit is estimating the amount of disturbance using information regarding the past difference in the left-right position and information regarding the current difference in the left-right position; Vehicle control device.

2. The vehicle control device according to claim 1, the information regarding the past difference in left-right position is a predicted value, and the information regarding the current difference in left-right position is an actual value; The disturbance estimation unit is estimating the amount of disturbance using a result of changing the actual value based on a difference between the predicted value and the actual value; Vehicle control device.

3. a lateral difference acquisition unit that acquires information regarding a lateral difference between a target trajectory of a vehicle and an actual trajectory of the vehicle; a disturbance estimation unit that estimates an amount of disturbance corresponding to the difference in the left-right position by using information regarding the difference in the left-right position acquired by the left-right direction difference acquisition unit; a tracking control unit that uses the disturbance amount estimated by the disturbance estimation unit to obtain a control command for causing the vehicle to track the target trajectory; Equipped with The tracking control unit is a control command for a lateral acceleration of the vehicle as the control command is obtained so as to reduce a difference in the position in the left-right direction, and the control command for the lateral acceleration is obtained so as to compensate for a difference between a left-right gradient of a road surface on the target trajectory and a left-right gradient of a road surface on the actual trajectory. Vehicle control device.

4. The vehicle control device according to claim 3, The tracking control unit is limiting a rate of change of the lateral acceleration control command within a predetermined range; Vehicle control device.

5. The vehicle control device according to claim 3, The tracking control unit is The control command for the lateral acceleration is made smaller when the actual trajectory is at a higher position in the lateral gradient of the road surface than the target trajectory, compared with when the actual trajectory is at a lower position. Vehicle control device.

6. The vehicle control device according to claim 3, The tracking control unit is The control command for the lateral acceleration is obtained using information on the difference in the left-right position as well as at least one of information on the orientation of the vehicle and information on the curvature of the target trajectory. Vehicle control device.

7. A vehicle control method executed by a vehicle control device mounted on a vehicle, comprising: obtaining information regarding a lateral position difference between a target trajectory of the vehicle and an actual trajectory of the vehicle; estimating an amount of disturbance corresponding to the difference in the left-right position using the acquired information on the difference in the left-right position; determining a control command for causing the vehicle to follow the target trajectory using the estimated disturbance amount; Equipped with The step of estimating the disturbance amount includes: estimating the amount of disturbance using information regarding the past difference in the left-right position and information regarding the current difference in the left-right position; A vehicle control method.

8. A vehicle control method executed by a vehicle control device mounted on a vehicle, comprising: obtaining information regarding a lateral position difference between a target trajectory of the vehicle and an actual trajectory of the vehicle; estimating an amount of disturbance corresponding to the difference in the left-right position using the acquired information on the difference in the left-right position; determining a control command for causing the vehicle to follow the target trajectory using the estimated disturbance amount; Equipped with The step of obtaining a control command includes: a control command for a lateral acceleration of the vehicle as the control command is obtained so as to reduce a difference in the position in the left-right direction, and the control command for the lateral acceleration is obtained so as to compensate for a difference between a left-right gradient of a road surface on the target trajectory and a left-right gradient of a road surface on the actual trajectory. A vehicle control method.

9. A vehicle control system mounted on a vehicle, comprising: A first control device, a second control device, and an actuator control device, The first control device is generating a target trajectory for the vehicle; The second control device is a lateral difference acquisition unit that acquires information regarding a difference in lateral positions between the target trajectory and an actual trajectory of the vehicle; a disturbance estimation unit that estimates an amount of disturbance corresponding to the difference in the left-right position by using information regarding the difference in the left-right position acquired by the left-right direction difference acquisition unit; a tracking control unit that uses the disturbance amount estimated by the disturbance estimation unit to obtain a control command for causing the vehicle to track the target trajectory; Equipped with The disturbance estimation unit is The disturbance amount is estimated using information regarding a difference in the left-right position in the past and information regarding a difference in the left-right position in the current state, The actuator control device includes: Obtaining the control command; Vehicle control system.

10. A vehicle control system mounted on a vehicle, comprising: A first control device, a second control device, and an actuator control device, The first control device is generating a target trajectory for the vehicle; The second control device is a lateral difference acquisition unit that acquires information regarding a difference in lateral positions between the target trajectory and an actual trajectory of the vehicle; a disturbance estimation unit that estimates an amount of disturbance corresponding to the difference in the left-right position by using information regarding the difference in the left-right position acquired by the left-right direction difference acquisition unit; a tracking control unit that uses the disturbance amount estimated by the disturbance estimation unit to obtain a control command for causing the vehicle to track the target trajectory; Equipped with The tracking control unit is a control command for a lateral acceleration of the vehicle as the control command is obtained so as to reduce a difference in the position in the left-right direction, and the control command for the lateral acceleration is obtained so as to compensate for a difference between a left-right gradient of a road surface on the target trajectory and a left-right gradient of the road surface on the actual trajectory, The actuator control device includes: Obtaining the control command; Vehicle control system.

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