Vehicle control device

Abstract

To provide a vehicle control system capable of controlling a wobble of a vehicle.SOLUTION: A vehicle control system of an embodiment includes a lateral position acquisition unit that acquires a lateral position of a vehicle, a feedforward control unit that determines a feedforward steering angle associated with a target yaw rate, a feedback control unit that determines a feedback steering angle on the basis of a yaw rate measured by a yaw rate sensor and a steering angle measured by a steering angle sensor, a steering angle determination unit that determines a steering angle of the vehicle on the basis of the feedforward steering angle and feedback steering angle, a wobble decision unit that detects a wobble of the vehicle on the basis of a change in the lateral position of the vehicle due to passage of time, and a correction unit that, when a wobble of the vehicle is detected by the wobble decision unit, corrects the feedback steering angle so that a variation quantity of the feedback steering angle relative to an average value over an immediate certain period of time is dwindle.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device that controls the steering angle of a vehicle.

Background Art

[0002] A vehicle control device that controls the steering angle of a vehicle is known. For example, Patent Document 1 below describes a travel control device mounted on a vehicle that towes a trailer and calculates a target steering angle for following a target route. When this travel control device detects the roll vibration of the trailer, it calculates a correction steering angle that reduces the roll vibration, and performs steering correction in accordance with the period and phase of the roll vibration of the trailer with the calculated correction steering angle as a base point for the target steering angle, thereby reducing the roll vibration of the trailer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The device described in Patent Document 1 calculates the target steering angle by adding the steering angle calculated from the curvature of the target route by feedforward control and the steering angle calculated from the lateral position deviation and yaw angle deviation with respect to the target route by feedback control. In such feedback control, depending on the characteristics of the vehicle, the feedback amount of the steering angle may vary greatly, and the vehicle may wobble. In particular, a coupled vehicle that towes a trailer has a more complex behavior than an uncoupled vehicle such as a truck, so in general feedback control, the feedback amount of the steering angle becomes excessive and wobbling is likely to occur.

[0005] Therefore, an object of the present disclosure is to provide a vehicle control device that can suppress the wobbling of a vehicle.

Means for Solving the Problem

[0006] In one aspect, there is provided a vehicle control device mounted on a vehicle having a yaw rate sensor for measuring a yaw rate and a steering angle sensor for measuring a steering angle, and controlling the steering angle of the vehicle so that the yaw rate of the vehicle becomes a target yaw rate. This vehicle control device includes a lateral position acquisition unit that acquires the lateral position of the vehicle, a feedforward control unit that determines a feedforward steering angle corresponding to the target yaw rate, a feedback control unit that determines a feedback steering angle based on the yaw rate of the vehicle measured by the yaw rate sensor and the steering angle of the vehicle measured by the steering angle sensor, a target steering angle determination unit that determines a target steering angle of the vehicle based on the feedforward steering angle and the feedback steering angle, a wobbling determination unit that detects the wobbling of the vehicle based on the change over time of the lateral position of the vehicle, and a correction unit that corrects the feedback steering angle so that the amount of variation with respect to the average value of the feedback steering angle in a recent fixed period becomes small when the wobbling of the vehicle is detected.

[0007] In this aspect, when the wobbling of the vehicle is detected, the feedback steering angle is corrected so that the amount of variation with respect to the average value of the feedback steering angle in a recent fixed period becomes small. In this way, by reducing the amount of variation of the feedback steering angle, the variation of the target steering angle also becomes small, so that the wobbling of the vehicle can be suppressed.

[0008] In one embodiment, the wobbling determination unit may determine that wobbling has occurred in the vehicle when the number of times the amount of variation of the lateral position exceeds a first threshold within a predetermined period is equal to or greater than a second threshold. In this way, by determining the wobbling of the vehicle using the amount of variation of the lateral position of the vehicle, the wobbling of the vehicle can be appropriately detected.

[0009] In one embodiment, the correction unit may stop correcting the feedback steering angle when the amount of change in the curvature of the vehicle's driving lane becomes equal to or greater than a third threshold value. When the curvature of the driving lane changes, the average value of the feedback steering angle changes, making it difficult to appropriately correct the feedback steering angle. In this embodiment, since the correction of the feedback steering angle is stopped when the amount of change in the curvature of the driving lane becomes large, appropriate steering angle control according to the driving environment can be performed.

[0010] In one embodiment, the correction unit may stop correcting the feedback steering angle when the amount of change in the inclination angle in the width direction of the vehicle's driving lane becomes equal to or greater than a fourth threshold value. When the inclination angle in the width direction of the driving lane changes, the average value of the feedback steering angle changes, making it difficult to appropriately correct the feedback steering angle. In this embodiment, since the correction of the feedback steering angle is stopped when the amount of change in the inclination angle in the width direction of the driving lane becomes large, appropriate steering angle control according to the driving environment can be performed.

[0011] In one embodiment, the correction unit may stop correcting the feedback steering angle when the amount of change in the lateral position of the vehicle becomes equal to or greater than a fifth threshold value. When the amount of change in the lateral position of the vehicle is large, there is a possibility that the steering angle control is not being performed appropriately. In this embodiment, since the correction of the feedback steering angle is stopped when the amount of change in the lateral position of the vehicle becomes large, appropriate steering angle control can be performed.

Advantages of the Invention

[0012] According to one aspect and various embodiments of the present invention, vehicle wobbling can be suppressed.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the vehicle control device according to various embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals, and duplicate descriptions of the same or corresponding parts will be omitted.

[0015] FIG. 1 is a block diagram showing the functional configuration of a vehicle equipped with a vehicle control device according to an embodiment. The vehicle control device 10 shown in FIG. 1 is mounted on the vehicle 1 and controls the steering angle of the vehicle 1 so that the vehicle 1 travels along the driving lane.

[0016] The vehicle 1 equipped with the vehicle control device 10 is, for example, a freight vehicle for loading goods. In one embodiment, the vehicle 1 may be a coupled vehicle including a trailer connected to the tractor at a connection point. The connection point is constituted by, for example, a coupler provided on the tractor side and a pin provided on the trailer side. The trailer of the vehicle 1 turns around the connection point as the yaw angle of the tractor changes.

[0017] As shown in FIG. 1, the vehicle 1 includes an external sensor 2, a steering angle sensor 3, a yaw rate sensor 4, a vehicle speed sensor 5, a steering actuator 6, and a vehicle control device 10. The external sensor 2 detects information on the external environment of the vehicle 1. As the external sensor 2, for example, a camera is used. The camera captures an image in front of the vehicle 1. The camera may be a monocular camera or a stereo camera. The stereo camera has two imaging units arranged to reproduce binocular parallax. The imaging information of the stereo camera also includes information in the depth direction.

[0018] The steering angle sensor 3 measures the steering angle (the amount of rotation of the steering shaft) of the vehicle 1. The yaw rate sensor 4 measures the yaw rate of the vehicle 1. The yaw rate is the rotational angular velocity around the vertical axis of the vehicle 1. As the yaw rate sensor 4, for example, a gyro sensor is used. The vehicle speed sensor 5 detects the speed of the vehicle 1. As the vehicle speed sensor 5, for example, a wheel speed sensor provided on the drive shaft of the vehicle 1 and detecting the rotational speed of the wheels is used. The steering angle sensor 3, the yaw rate sensor 4, and the vehicle speed sensor 5 output information indicating the measured steering angle, yaw rate, and speed of the vehicle 1 to the vehicle control device 10.

[0019] The steering actuator 6 controls the drive of the electric power steering system according to a control signal from the vehicle control device 10. By controlling the drive of the electric power steering system, the steering angle of the vehicle 1 is controlled.

[0020] The vehicle control device 10 is an electronic control unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a CAN (Controller Area Network) communication circuit, etc. The vehicle control device 10 is connected to a network that communicates using, for example, a CAN communication circuit, and is communicably connected to each component of the vehicle 1. The vehicle control device 10 realizes various functions described later, for example, by operating the CAN communication circuit to input and output data based on a signal output by the CPU, storing the data in the RAM, loading the program stored in the ROM into the RAM, and executing the program loaded into the RAM. The vehicle control device 10 may be composed of a plurality of electronic control units.

[0021] The vehicle control device 10 controls the steering angle of the vehicle 1 so that the yaw rate of the vehicle 1 becomes the target yaw rate. As shown in FIG. 1, the vehicle control device 10 functionally includes a lateral position acquisition unit 11, a feedforward control unit 12, a feedback control unit 13, a wobbling determination unit 14, an average feedback steering angle calculation unit 15, a correction unit 16, and a target steering angle determination unit 17.

[0022] The lateral position acquisition unit 11 acquires the lateral position of the vehicle 1 (the position of the vehicle 1 in the width direction within the driving lane) based on the information output from the external sensor 2. For example, the lateral position acquisition unit 11 extracts the lane dividing line (white line) of the driving lane from the image captured by the camera, and detects the lateral position of the vehicle 1 based on the positional relationship between the vehicle and the dividing line.

[0023] The feedforward control unit 12 determines the feedforward steering angle δ t corresponding to the target yaw rate γ ff As shown in FIG. 1, the feedforward control unit 12 includes a target yaw rate setting unit 21 and a feedforward steering angle determination unit 22. The target yaw rate setting unit 21 detects, for example, the curvature of the driving lane in front of the vehicle 1 from the image captured by the external sensor 2, and determines the target yaw rate γ t corresponding to the curvature. The target yaw rate γ t is the yaw rate at which the vehicle 1 travels along the driving lane having the detected curvature.

[0024] The feedforward steering angle determination unit 22 determines the feedforward steering angle δ t corresponding to the target yaw rate γ ff The feedforward steering angle δ ff is the steering angle that makes the yaw rate of the vehicle 1 the target yaw rate γ t For example, the feedforward steering angle determination unit 22 calculates the feedforward steering angle δ ff by solving the following equation (1).

[0025]

Equation

[0026] In Equation (1), P is a conversion formula for converting the yaw rate into the steering angle. The conversion formula P is expressed, for example, as the following equation (2).

[0027]

Number

[0028] In Equation (2), l represents the wheelbase, Ks represents the stability factor, and V represents the speed of Vehicle 1. The wheelbase l and the stability factor Ks are preset values.

[0029] The feedback control unit 13 determines the feedback steering angle δ based on the yaw rate γ of Vehicle 1 measured by the yaw rate sensor 4 m and the steering angle δ of Vehicle 1 measured by the steering angle sensor 3. m As shown in FIG. 1, the feedback control unit 13 includes a filter 23, a steering angle conversion unit 24, and a differentiator 25. The filter 23 performs a filtering process on the steering angle δ of Vehicle 1 measured by the steering angle sensor 3 according to the following Equation (3) fb to calculate the steering angle δ1. In Equation (3), a represents the cut-off frequency, and s represents the Laplace operator. m

[0030]

Number

[0031] The steering angle conversion unit 24 calculates a steering angle δ2 corresponding to the yaw rate γ of Vehicle 1 measured by the yaw rate sensor 4. m For example, the steering angle conversion unit 24 converts the yaw rate γ into the steering angle δ2 according to the following Equation (4). m

[0032]

Number

[0033] In Equation (4), τ represents the response delay of the vehicle. The term (1 + τs) / P in Equation (4) corresponds to the reciprocal of the plant model of the first-order lag system. That is, the feedback control unit 13 assumes the plant model of the vehicle 1 as a first-order lag system and the yaw rate γ m is converted into the steering angle δ2.

[0034] The differentiator 25 outputs the difference between the steering angle δ1 output from the filter 23 and the steering angle δ2 output from the steering angle conversion unit 24 as the feedback steering angle δ fb . As described above, the feedforward steering angle δ ff determined by the feedforward control unit 12 is the steering angle corresponding to the target yaw rate γ t . However, in reality, disturbances such as a cant (gradient in the width direction) and a crosswind act on the vehicle 1. Therefore, if the steering angle of the vehicle 1 is set to the feedforward steering angle δ ff , a deviation will occur between the yaw rate of the vehicle 1 and the target yaw rate. The feedback steering angle δ fb is the steering angle for suppressing the disturbance acting on the vehicle 1.

[0035] Here, in a articulated vehicle, the tractor and the trailer affect each other, so it moves in a complex manner. For this reason, when the feedback steering angle δ fb according to the plant model of a general first-order lag system is fed back, the steering angle of the vehicle 1 may become excessive compared to the steering angle that should be given to cancel the disturbance. When feedback processing is performed using an excessive feedback steering angle δ fb , the vehicle 1 may wobble and the behavior of the vehicle 1 may become unstable.

[0036] The wobbling determination unit 14 detects the wobbling of the vehicle 1 based on the change over time of the lateral position of the vehicle 1. For example, the wobbling determination unit 14 generates time-series data indicating the change over time of the lateral position of the vehicle 1 acquired by the lateral position acquisition unit 11. FIG. 2 shows an example of the time-series data indicating the change over time of the lateral position of the vehicle 1. The wobbling determination unit 14 measures the number of times the amplitude (the variation value between adjacent peaks) AMP of the time-series data of the lateral position exceeds a first threshold value, and determines that wobbling has occurred in the vehicle 1 when the number of times the amplitude AMP exceeds the first threshold value within a predetermined period is equal to or greater than a second threshold value.

[0037] That is, the wobbling determination unit 14 determines that wobbling has occurred in the vehicle when the number of times the amount of variation in the lateral position of the vehicle 1 exceeds the first threshold value within a predetermined period is equal to or greater than the second threshold value. On the other hand, the wobbling determination unit 14 determines that no wobbling has occurred in the vehicle 1 when the number of times the amount of variation in the lateral position of the vehicle 1 exceeds the first threshold value within a predetermined period is less than the second threshold value. The wobbling determination unit 14 outputs information indicating the presence or absence of wobbling to the correction unit 16.

[0038] The average feedback steering angle calculation unit 15 calculates the average value of the feedback steering angle δ fb output from the feedback control unit 13. For example, the average feedback steering angle calculation unit 15 generates time-series data of the feedback steering angle δ fb and calculates the average value of the feedback steering angle δ fb in a recent fixed period. Then, the calculated average value of the feedback steering angle δ fb is output to the correction unit 16 as the average feedback steering angle δ avr .

[0039] When the wobbling of the vehicle 1 is detected by the wobbling determination unit 14, the correction unit 16 corrects the feedback steering angle δ avr so that the amount of variation with respect to the average feedback steering angle δ fb becomes smaller. FIG. 3 is a block diagram showing the functional configuration of the correction unit 16. As shown in FIG. 3, the correction unit 16 includes a differentiator 31, a yaw rate conversion unit 32, a corrected steering angle calculation unit 33, and an adder 34.

[0040] The differentiator 31 outputs the difference between the feedback rudder angle δ determined by the feedback control unit 13 and the average feedback rudder angle δ output from the average feedback rudder angle calculation unit 15 as the rudder angle Δδ. The rudder angle Δδ is the amount of variation of the feedback rudder angle δ with respect to the average feedback rudder angle δ. fb and the average feedback rudder angle δ output from the average feedback rudder angle calculation unit 15 as the rudder angle Δδ. avr and outputs the difference as the rudder angle Δδ. The rudder angle Δδ is the amount of variation of the feedback rudder angle δ with respect to the average feedback rudder angle δ. avr with respect to the average feedback rudder angle δ fb of the feedback rudder angle δ.

[0041] The yaw rate conversion unit 32 converts the rudder angle Δδ into a yaw rate Δγ using the conversion formula P. For example, the yaw rate conversion unit 32 calculates the yaw rate Δγ according to the following formula (5).

[0042]

Equation

[0043] The corrected rudder angle calculation unit 33 multiplies the yaw rate Δγ by a gain and then converts the yaw rate back into a rudder angle using the conversion formula P to calculate the corrected rudder angle Δδ. For example, the corrected rudder angle calculation unit 33 calculates the corrected rudder angle Δδ according to the following formula (6). c and calculates the corrected rudder angle Δδ. For example, the corrected rudder angle calculation unit 33 calculates the corrected rudder angle Δδ according to the following formula (6). c to calculate.

[0044]

Equation

[0045] Here, in formula (6), G represents the gain. When correcting the feedback rudder angle δ, the corrected rudder angle calculation unit 33 sets the gain G to a value smaller than 1. For example, the gain G is set to be 0.3 or more and 0.7 or less. The gain G may be set to 0.5. By setting the gain G to a value smaller than 1, the corrected rudder angle Δδ becomes smaller than the rudder angle Δδ. As will be described later, the corrected rudder angle Δδ is the average feedback rudder angle δ fb when correcting, the gain G is set to a value smaller than 1. For example, the gain G is set to be 0.3 or more and 0.7 or less. The gain G may be set to 0.5. By making the gain G smaller than 1, the corrected rudder angle Δδ c becomes smaller than the rudder angle Δδ. As will be described later, the corrected rudder angle Δδ c is the average feedback rudder angle δ avrSince it is the amount of change in the rudder angle with respect to, by making the gain G smaller than 1, the amount of change in the target rudder angle δ t becomes smaller. The correction rudder angle calculation unit 33 outputs the calculated correction rudder angle Δδ c to the adder 34.

[0046] The adder 34 adds (1 - G)·δ c to the correction rudder angle Δδ avr output from the correction rudder angle calculation unit 33, and outputs it as the correction feedback rudder angle δ cfb . The correction feedback rudder angle δ cfb is the feedback rudder angle corrected by the correction unit 16. FIG. 4 is a diagram showing the feedback rudder angle δ fb before correction and the correction feedback rudder angle δ cfb arranged on the same time axis. As shown in FIG. 4, by adding (1 - G)·δ c to the correction rudder angle Δδ avr , the average value of the correction feedback rudder angle δ cfb becomes equal to the average feedback rudder angle δ avr . Since the average value of the correction feedback rudder angle δ cfb coincides with the average value of the feedback rudder angle δ fb before correction, even when a disturbance such as a gust acts on the vehicle 1, a rudder angle that cancels out the disturbance can be fed back.

[0047] As described above, the correction feedback rudder angle δ cfb is the correction rudder angle Δδ which is the amount of change in the rudder angle c added to the average feedback rudder angle δ avr . Since the correction rudder angle Δδ c is smaller than the rudder angle Δδ before correction, the correction feedback rudder angle δ cfb can be said to be a rudder angle with a smaller amount of change with respect to the average feedback rudder angle δ fb than the feedback rudder angle δ avr .

[0048] As shown in FIG. 1, the correction feedback rudder angle δ cfbis output to the target rudder angle determination unit 17. Note that the corrected feedback rudder angle δ cfb may be output to the target rudder angle determination unit 17 after performing saturation control so that sudden changes in the rudder angle do not occur.

[0049] On the other hand, when the fluctuation determination unit 14 determines that the vehicle 1 is not fluctuating, the correction unit 16 outputs the feedback rudder angle δ fb to the target rudder angle determination unit 17 without correction. For example, the correction unit 16 outputs the uncorrected feedback rudder angle δ fb to the target rudder angle determination unit 17 by setting the gain G to 1.

[0050] In addition, when a change occurs in the driving environment of the vehicle 1, the correction unit 16 may stop correcting the feedback rudder angle δ fb because it is highly likely to vary greatly from the average feedback rudder angle δ avr . For example, when the amount of change in the curvature of the driving lane, the amount of change in the cant angle (the inclination angle in the width direction of the driving lane), or the amount of change in the lateral position of the vehicle becomes equal to or greater than a threshold value, the correction unit 16 stops correcting the feedback rudder angle δ fb and may output the feedback rudder angle δ fb to the target rudder angle determination unit 17. Note that the amount of change in curvature means, for example, the difference between the curvature of the driving lane at the time when the correction of the feedback rudder angle δ fb is started by the correction unit 16 and the curvature of the most recent driving lane. The amount of change in the cant angle means, for example, the difference between the cant angle of the driving lane at the time when the correction of the feedback rudder angle δ fb is started by the correction unit 16 and the cant angle of the most recent driving lane. The amount of change in the lateral position means, for example, the difference between the lateral position of the vehicle at the time when the correction of the feedback rudder angle δ fb is started by the correction unit 16 and the lateral position of the most recent vehicle. fb The amount of change in the lateral position means, for example, the difference between the lateral position of the vehicle at the time when the correction of the feedback rudder angle δ

[0051] Based on the feedforward rudder angle δ ff and the corrected feedback rudder angle δ cfb , the target rudder angle determination unit 17 determines the target rudder angle δ of the vehicle.t Determine it. For example, when the vehicle 1 is wobbling, the target steering angle determination unit 17 sets the feedforward steering angle δ ff and the correction feedback steering angle δ cfb and outputs the sum as the target steering angle δ t to the steering actuator 6. The target steering angle δ t is the steering angle that makes the yaw rate of the vehicle 1 the target yaw rate γ t . When the vehicle 1 is not wobbling, the target steering angle determination unit 17 outputs the sum of the feedforward steering angle δ ff and the feedback steering angle δ fb before correction as the target steering angle δ t to the steering actuator 6.

[0052] The steering actuator 6 controls the drive of the electric power steering system so that the steering angle of the vehicle 1 becomes the target steering angle δ t . By controlling the steering angle of the vehicle 1 to approach the target steering angle δ t , the vehicle 1 can be made to travel along the driving lane. Also, since the variation amount of the correction feedback steering angle δ cfb with respect to the average feedback steering angle δ fb is smaller than that of the feedback steering angle δ avr , the target steering angle δ t is a steering angle with a small variation amount. By controlling the steering angle of the vehicle 1 so as to become such a target steering angle δ t , the wobbling of the vehicle 1 can be suppressed.

[0053] Next, with reference to FIG. 5, the operation of the vehicle control device 10 will be described. FIG. 5 is a flowchart showing the operation flow of the vehicle control device 10. As shown in FIG. 5, first, the vehicle control device 10 acquires various sensor information measured by the external sensor 2, the steering angle sensor 3, the yaw rate sensor 4, and the vehicle speed sensor 5 (step ST1). For example, the vehicle control device 10 acquires the image information in front of the vehicle 1, the steering angle δ m , the yaw rate γ m , and the vehicle speed.

[0054] Next, the feedforward control unit 12 of the vehicle control device 10 calculates a target yaw rate γ corresponding to the curvature of the lane in which the vehicle is traveling. t and determines a feedforward steering angle δ corresponding to the target yaw rate γ (step ST2). t ff ff ff

[0055] Next, the feedback control unit 13 of the vehicle control device 10 determines a feedback steering angle δ based on the steering angle δ and yaw rate γ of the vehicle 1 (step ST3). The feedback steering angle δ is determined based on, for example, the difference between a steering angle δ1 obtained from the steering angle δ of the vehicle 1 and a steering angle δ2 corresponding to the yaw rate γ of the vehicle 1. m m m fb fb fb fb fb m m m m

[0056] Next, the wobbling determination unit 14 determines whether wobbling has occurred in the vehicle 1 (step ST4). The wobbling determination unit 14 determines that wobbling has occurred in the vehicle 1, for example, when the number of times the fluctuation amount of the lateral position of the vehicle 1 exceeds a first threshold within a predetermined period is equal to or greater than a second threshold.

[0057] When it is determined that wobbling has occurred in the vehicle 1, the correction unit 16 corrects the feedback steering angle δ to a corrected feedback steering angle δ (step ST5). The corrected feedback steering angle δ is a steering angle with a smaller variation amount with respect to the average feedback steering angle δ than the feedback steering angle δ. Also, the average value of the corrected feedback steering angle δ coincides with the average feedback steering angle δ. fb cfb cfb cfb cfb cfb fb fb avr avr cfb cfb avr avr

[0058] Next, the correction unit 16 determines whether or not the amount of change in the curvature of the driving lane over a certain period is less than a third threshold value (step ST6). If the amount of change in the curvature is less than the third threshold value, the correction unit 16 determines whether or not the amount of change in the cant angle of the driving lane over a certain period is less than a fourth threshold value (step ST7). If the amount of change in the cant angle is less than the fourth threshold value, the correction unit 16 determines whether or not the amount of change in the lateral position of the vehicle 1 within the driving lane over a certain period is less than a fifth threshold value (step ST8).

[0059] If the amount of change in the lateral position of the vehicle 1 is less than the fifth threshold value, the target steering angle determination unit 17 determines the target steering angle δ ff based on the feedforward steering angle δ cfb and the corrected feedback steering angle δ t (step ST9). For example, the target steering angle δ t is the steering angle obtained by adding the feedforward steering angle δ ff and the corrected feedback steering angle δ cfb . Next, the steering actuator 6 controls the steering device so that the steering angle of the vehicle 1 becomes the target steering angle δ t (step ST10). Then, the processing of steps ST5 to ST10 is repeatedly executed at a predetermined cycle until the correction of the feedback steering angle δ fb is stopped.

[0060] On the other hand, when the amount of change in the curvature of the driving lane is greater than or equal to the third threshold value, the amount of change in the cant angle is greater than or equal to the fourth threshold value, or the amount of change in the lateral position of the vehicle 1 is greater than or equal to the fifth threshold value, the correction unit 16 stops the correction of the feedback steering angle δ fb . Then, the target steering angle determination unit 17 determines the target steering angle δ ff based on the feedforward steering angle δ fb and the uncorrected feedback steering angle δ t (step ST11). In this case, the target steering angle δ t is the steering angle obtained by adding the feedforward steering angle δ ff and the feedback steering angle δ fb . Next, the steering actuator 6 controls the steering device so that the steering angle of the vehicle 1 becomes the target steering angle δ tControl the steering device so as to achieve this (step ST12).

[0061] As described above, in the vehicle control device 10 of one embodiment, when the vehicle 1 is detected to be swaying, the feedback steering angle δ in the most recent fixed period fb The average feedback steering angle δ which is the average value of avr The feedback steering angle δ is corrected so that the amount of variation with respect to becomes small fb As a result, the variation of the feedback steering angle becomes small, and accordingly, the variation of the target steering angle δ of the vehicle 1 t Also becomes small. Therefore, it becomes possible to reduce the swaying of the vehicle 1. Further, the average value of the corrected feedback steering angle δ cfb Coincides with the average feedback steering angle δ avr Therefore, even when a disturbance such as a cant acts on the vehicle 1, the vehicle can be made to travel along the traveling lane.

[0062] Although the vehicle control device 10 according to various embodiments has been described above, various modifications can be configured without being limited to the above-described embodiments and without changing the gist of the invention.

Explanation of Reference Numerals

[0063] 1... Vehicle, 3... Steering angle sensor, 4... Yaw rate sensor, 10... Vehicle control device, 11... Lateral position acquisition unit, 12... Feedforward control unit, 13... Feedback control unit, 14... Determination unit, 16... Correction unit, 17... Target steering angle determination unit, γ t ... Target yaw rate, δ fb ... Feedback steering angle, δ ff ... Feedforward steering angle, δ t ... Target steering angle.

Claims

1. A vehicle control device mounted on a vehicle having a yaw rate sensor for measuring a yaw rate and a rudder angle sensor for measuring a rudder angle, the vehicle control device controlling the rudder angle of the vehicle so that the yaw rate of the vehicle becomes a target yaw rate, a lateral position acquisition unit that acquires the lateral position of the vehicle, a feedforward control unit that determines a feedforward rudder angle corresponding to the target yaw rate, a feedback control unit that determines a feedback rudder angle based on the yaw rate of the vehicle measured by the yaw rate sensor and the rudder angle of the vehicle measured by the rudder angle sensor, a target rudder angle determination unit that determines a target rudder angle of the vehicle based on the feedforward rudder angle and the feedback rudder angle, a wobbling determination unit that detects wobbling of the vehicle based on a change over time of the lateral position of the vehicle, a correction unit that corrects the feedback rudder angle so that a variation amount with respect to an average value of the feedback rudder angle in a recent fixed period becomes small when wobbling of the vehicle is detected, A vehicle control device comprising:

2. The vehicle control device according to claim 1, wherein the wobbling determination unit determines that wobbling has occurred in the vehicle when the number of times the variation amount of the lateral position exceeds a first threshold within a predetermined period is equal to or greater than a second threshold.

3. The vehicle control device according to claim 1 or 2, wherein the correction unit stops correcting the feedback rudder angle when a change amount of a curvature of a travel lane of the vehicle becomes equal to or greater than a third threshold.

4. The vehicle control device according to any one of claims 1 to 3, wherein the correction unit stops correcting the feedback rudder angle when a change amount of an inclination angle in a width direction of a travel lane of the vehicle becomes equal to or greater than a fourth threshold.

5. The vehicle control device according to any one of claims 1 to 4, wherein the correction unit stops correcting the feedback rudder angle when a change amount of the lateral position of the vehicle becomes equal to or greater than a fifth threshold.

Images