Steering device control device, steering device control method, and steering system

Abstract

To provide a control device for a steering device, a control method for a steering mechanism and a steering system capable of suppressing the deterioration of a vehicle behavior while suppressing the discomfort feeling of a driver.SOLUTION: A control device according to the present invention is provided for a vehicle that includes a steering device configured to be able to independently control the turning angle of a wheel relative to the operated amount of a steering operation input member, and inputs, regardless of the operated amount of the steering operation input member, a control signal for returning the turning angle of the wheel to a neutral position or therearound to a steering actuator when a physical quantity relating to the actual yaw rate of the vehicle is greater than a physical quantity relating to an estimated yaw rate based on the operated amount of the steering operation input member and of the running state of the vehicle.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] The vehicle attitude control device of Patent Document 1 controls the attitude of a vehicle in order to control the angle of the vehicle's traveling direction relative to a predetermined target direction, and the difference between the target slip angle β* and the vehicle body slip angle β (β*-β) is set to an angle difference Δβ, and at least one of the front wheels and rear wheels of the vehicle is controlled according to the relationship between the sign of the angle difference Δβ and the sign of the actual yaw rate γ. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5817359 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are cases where a difference occurs between the standard yaw rate (in other words, the estimated yaw rate) based on information such as the steering angle of the wheels (steered wheels) and the vehicle speed, and the actual yaw rate, and the steering angle of the wheels is controlled based on this difference. For example, it is conceivable that the driver may operate the steering wheel from a counter-steer state in which the steering angle of the wheels is pointing in the opposite direction, even though the driver is operating in the turning direction, which may cause discomfort to the driver and confusion in the driver's steering wheel operation.

[0005] The present invention has been made in consideration of the current situation, and its purpose is to provide a steering device control device, a steering device control method, and a steering system that can prevent deterioration of vehicle behavior while suppressing discomfort felt by the driver. [Means for solving the problem]

[0006] According to one aspect of the present invention, when a physical quantity relating to an actual yaw rate of a vehicle is larger than a physical quantity relating to an estimated yaw rate based on an operation amount of a steering operation input member and a running state of the vehicle, the steering angle of the wheels is adjusted to a predetermined value regardless of the operation amount of the steering operation input member. neutral position A control signal for steering back to the steering position is output to the steering actuator. Furthermore, according to another aspect of the present invention, when a physical quantity related to the actual yaw rate of the vehicle is greater than a physical quantity related to an estimated yaw rate based on the amount of operation of a steering operation input member and the running state of the vehicle, a control signal is output to a steering actuator to displace the steering angle of the wheels beyond the neutral position to the opposite side in accordance with the operation direction of the steering operation input member, regardless of the amount of operation of the steering operation input member. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress deterioration of vehicle behavior while suppressing the driver's sense of discomfort. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing one aspect of a steering system of a vehicle. [Figure 2] 1 is a flowchart illustrating an embodiment of a steering control process. [Figure 3] 4 is a time chart showing one aspect of the correlation between the operation angle of the steering wheel, the steering angle of the front wheels, and the yaw rate. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a steering device control device, a steering device control method, and a steering system according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of a steering system 200 mounted on a vehicle 100. As shown in FIG. The vehicle 100 is a four-wheeled vehicle having four wheels 101-104.

[0010] The steering system 200 includes a steering device 300 and a control device 400 for controlling an actuator of the steering device 300 . The steering device 300 has a steering wheel 301 which is a steering operation member operated by the driver, a reaction force actuator 302 which applies a reaction torque to the steering wheel 301, and a steering device 305 which can change the steering angle of the front wheels 101, 102 which are the steered wheels of the vehicle 100. The steering device 305 includes a steering actuator 304 that applies a steering torque (in other words, a steering force) to the front wheels 101 and 102 via a steering member 303 .

[0011] The steering device 300 uses, for example, electric motors as the reaction force actuator 302 and the steering actuator 304 . The steering device 300 is a steer-by-wire type steering device in which the steering wheel 301 and the front wheels 101, 102, which are the steered wheels, i.e., the steering device 305, are mechanically separated, and the steering angles (in other words, tire angles) of the front wheels 101, 102 can be independently controlled in response to the operation angle (in other words, the operation amount) of the steering wheel 301.

[0012] The control device 400 is an electronic control device including an MCU (Micro Controller Unit) 401 and the like. When the steering actuator 304 is an electric motor, the control device 400 can be provided with a pre-driver and an inverter for controlling the supply of electricity to the electric motor, together with the MCU 401, and can also be a system provided with a drive circuit including a pre-driver and an inverter, separate from the control device 400.

[0013] The MCU 401 can also be referred to as a microcomputer, a processor, a processing unit, an arithmetic unit, or the like. The MCU 401 of the control device 400 acquires status information, which is information about the status of the vehicle 100 and the steering device 300, from various sensors, calculates a control signal for the reaction force actuator 302 and a control signal for the steering actuator 304 based on the acquired status information, and controls the reaction force torque and steering torque, i.e., the steering angle σ of the front wheels 101, 102, by outputting the calculated control signals.

[0014] Vehicle 100 is equipped with sensors that detect the driving state of vehicle 100, such as wheel speed sensors 403-406 that detect the wheel speed of each of wheels 101-104, a yaw rate sensor 407 that detects the yaw rate γ of vehicle 100, and an acceleration sensor 408 that detects the longitudinal acceleration and lateral acceleration of vehicle 100. The steering device 300 also includes, as sensors for detecting the operating state of the steering device 300, an operation angle sensor 411 for detecting an operation angle θ of the steering wheel 301, and a steering angle sensor 412 for detecting a steering angle σ of the front wheels 101, 102.

[0015] The operation angle sensor 411 detects the neutral position of the steering wheel 301 as 0 degrees. The operation angle sensor 411 detects the operation angle θ as a positive angle when the steering wheel 301 is operated to the left from the neutral position, and detects the operation angle θ as a negative angle when the steering wheel 301 is operated to the right from the neutral position. Similarly, the steering angle sensor 412 detects the neutral position of the front wheels 101, 102 as 0 degrees. The steering angle sensor 412 detects the steering angle σ as a positive angle when the front wheels 101, 102 are steered to the left from the neutral position, and detects the steering angle σ as a negative angle when the front wheels 101, 102 are steered to the right from the neutral position.

[0016] The neutral position of the front wheels 101, 102, which are steered wheels, is a position where the front wheels 101, 102 are not steered to either the left or right, and the vehicle 100 travels straight ahead. The neutral position of the steering wheel 301 is a position where the steering wheel 301 is not operated to either the left or right and the front wheels 101, 102 are in a neutral position. The yaw rate sensor 407 detects the rate of change as a positive value when a left yaw occurs, and detects the rate of change as a negative value when a right yaw occurs.

[0017] Here, the MCU 401 acquires information such as the operation angle θ of the steering wheel 301, and calculates the target steering angle σtg of the front wheels 101, 102 based on the acquired information. Then, the MCU 401 calculates a control signal for the steering actuator 304 so that the actual steering angle σ detected by the steering angle sensor 412 approaches the target steering angle σtg, and outputs the calculated control signal to the steering actuator 304 . In other words, the MCU 401 constitutes a control unit that outputs a control signal to the steering actuator 304 based on a physical quantity related to the operation angle θ of the steering wheel 301 . When the steering actuator 304 is an electric motor, the steering actuator 304 is controlled and driven by, for example, the MCU 401, a pre-driver, and an inverter.

[0018] Furthermore, when the vehicle 100 behaves unstable, the MCU 401 performs steering control to stabilize the behavior of the vehicle 100 by correcting the steering angle σ of the front wheels 101, 102 regardless of the operation angle θ of the steering wheel 301. In detail, when the vehicle 100 is in an oversteer state, the MCU 401 outputs a control signal to the steering actuator 304 to return the steering angle σ of the front wheels 101, 102 to near the neutral position, independently of the driver's operation of the steering wheel 301. As a result, before the driver senses the oversteer state and operates the steering wheel 301, the steering angle σ is corrected and the increase in yaw rate is suppressed, making it easier for the driver to respond to the oversteer state and stabilizing the behavior of the vehicle 100.

[0019] FIG. 2 is a flowchart showing a steering control process for stabilizing the behavior of the vehicle 100. In step S501, the MCU 401 calculates a target steering angle σtg_a (basic steering angle command value) of the front wheels 101, 102 based on information about the steering angle θ of the steering wheel 301 detected by the steering angle sensor 411. In detail, the MCU 401 multiplies the operation angle θ by the steering gear ratio to obtain the target steering angle σtg_a.

[0020] Next, in step S502, the MCU 401 estimates the yaw rate of the vehicle 100 from the steering angle σ of the front wheels 101, 102 detected by the steering angle sensor 412 and the running state of the vehicle 100, and performs processing to set the estimation result as an estimated yaw rate γi. The estimated yaw rate γi is a standard yaw rate that occurs when the vehicle 100 is not in an oversteer state.

[0021] As a method for estimating the yaw rate of the vehicle 100 from the steering angle σ and the running state of the vehicle 100, various known methods can be applied. For example, the MCU 401 can calculate the estimated yaw rate γi according to Equation 1 based on the steering angle σ of the front wheels 101, 102 detected by the steering angle sensor 412 and the vehicle speed V of the vehicle 100 calculated from the output signals of the wheel speed sensors 403-406.

number

[0022] Next, in step S503, the MCU 401 compares the actual yaw rate γ detected by the yaw rate sensor 407 with the estimated yaw rate γi obtained in step S502. Specifically, the MCU 401 determines whether the absolute value of the actual yaw rate γ is greater than the value obtained by adding a threshold value α (α≧0) to the absolute value of the estimated yaw rate γi.

[0023] In other words, in step S503, the MCU 401 determines whether the actual yaw rate γ is greater than the estimated yaw rate γi and the difference between the actual yaw rate γ and the estimated yaw rate γi is greater than the threshold value α. The actual yaw rate γ is not limited to the value detected by the yaw rate sensor 407, and the MCU 401 can obtain the actual yaw rate γ based on a physical quantity related to the running state of the vehicle 100. For example, the MCU 401 can obtain the actual yaw rate γ from the detected value of the lateral acceleration (centripetal acceleration) of the vehicle 100 and the vehicle speed V.

[0024] Here, if the vehicle 100 is not in an oversteer state, the actual yaw rate γ is close to the estimated yaw rate γi, and therefore (|γi|+α)<|γ| does not hold. Therefore, if (|γi|+α)<|γ| is not true, MCU 401 determines that the vehicle 100 is in a stable state where its behavior is commensurate with the steering angle σ, and that there is no need to modify the steering angle σ to stabilize the behavior, and proceeds to step S504.

[0025] In step S504, the MCU 401 sets the correction steering angle σ_c, which is a correction value for correcting the target steering angle σtg_a, to zero, and cancels the correction process for the target steering angle σtg_a. That is, as will be described in detail later, the MCU 401 subtracts the correction steering angle σ_c from the absolute value of the target steering angle σtg_a and sets the result as the final target steering angle σtg. Therefore, if the corrective steering angle σ_c is zero, the target steering angle σtg_a=the target steering angle σtg, and the target steering angle σtg_a is not substantially corrected.

[0026] On the other hand, when the vehicle 100 is in an oversteer state, the actual yaw rate γ becomes larger than the estimated yaw rate γi, and (|γi|+α)<|γ| holds. Therefore, if (|γi|+α)<|γ| is established, the MCU 401 proceeds to step S505 to perform processing to correct the target steering angle σtg_a in order to suppress an increase in the yaw rate.

[0027] In step S505, the MCU 401 calculates a correction steering angle σ_c for returning the steering angle σ of the front wheels 101, 102 to near the neutral position, regardless of the operation angle θ of the steering wheel 301. In other words, when the actual yaw rate γ becomes larger than the estimated yaw rate γi, the MCU 401 controls the steering angle σ of the front wheels 101, 102 to return to near the neutral position, thereby suppressing deterioration of the behavior and posture of the vehicle 100 (increase in yaw rate).

[0028] In step S505, the MCU 401 calculates a correction steering angle σ_c for correcting the target steering angle σtg_a in accordance with Equations 2 to 4.

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[0029] The MCU 401 uses Equation 2 to calculate a first correction steering angle σ_c1 that is proportional to the difference between the actual yaw rate γ and the estimated yaw rate γi. In addition, in Equation 2, the sign of the first corrected steering angle σ_c1 is determined depending on the sign of the actual yaw rate γ and the sign of the estimated yaw rate γi.

[0030] In other words, if the sign of the actual yaw rate γ and the sign of the estimated yaw rate γi are the same, in other words, if the yaw generation direction of the actual yaw rate γ and the yaw generation direction of the estimated yaw rate γi are the same, the first correction steering angle σ_c1 is calculated as a positive value. Conversely, if the sign of the actual yaw rate γ differs from the sign of the estimated yaw rate γi, in other words, if the yaw generation direction of the actual yaw rate γ differs from the yaw generation direction of the estimated yaw rate γi, the first correction steering angle σ_c1 is calculated as a negative value.

[0031] In addition, when the actual yaw rate γ is larger than the estimated yaw rate γi and the difference between the actual yaw rate γ and the estimated yaw rate γi is larger than the threshold value α, the MCU 401 proceeds to step S505, so the difference between the actual yaw rate γ and the estimated yaw rate γi in equation 2 is larger than the threshold value α. That is, the MCU 401 corrects the target steering angle σtg_a when the difference between the actual yaw rate γ and the estimated yaw rate γi is greater than the threshold value α. Then, when the difference between the actual yaw rate γ and the estimated yaw rate γi becomes smaller than the threshold value α due to the correction of the target steering angle σtg_a, in other words, when the yaw rate difference converges, the MCU 401 sets the correction steering angle σ_c to zero and returns to a state in which the steering angle σ is controlled to the target steering angle σtg_a based on the operating angle θ of the steering wheel 301.

[0032] Furthermore, the MCU 401 sets the larger value of the first corrected steering angle σ_c1 or 0 deg as the second corrected steering angle σ_c2 using Equation 3. Therefore, when the first correction steering angle σ_c1>0 is established, the second correction steering angle σ_c2 is set to the second correction steering angle σ_c2=the first correction steering angle σ_c1. On the other hand, when the first correction steering angle σ_c1≦0 holds, the second correction steering angle σ_c2 is set to the second correction steering angle σ_c2=0 deg.

[0033] Furthermore, the MCU 401 determines the smaller of the second correction steering angle σ_c2 and the absolute value of the target steering angle σtg_a as the correction steering angle σ_c using Equation 4. As will be described later, the MCU 401 performs a correction to reduce the absolute value of the target steering angle σtg_a by using the corrected steering angle σ_c, and obtains the final target steering angle σtg. Therefore, when the corrective steering angle σ_c is the same angle as the absolute value of the target steering angle σtg_a, the target steering angle σtg is 0 deg, that is, the neutral position.

[0034] On the other hand, when the corrective steering angle σ_c is set to an angle greater than the absolute value of the target steering angle σtg_a, the target steering angle σtg exceeds the neutral position and becomes an angle opposite to the target steering angle σtg_a. Here, in Equation 4, the process of setting the smaller of the second correction steering angle σ_c2 and the absolute value of the target steering angle σtg_a as the correction steering angle σ_c is a process of setting the correction steering angle σ_c to be equal to or smaller than the absolute value of the target steering angle σtg_a.

[0035] Therefore, in the correction process using the correction steering angle σ_c, the target steering angle σtg is prevented from exceeding the neutral position and becoming an angle on the opposite side, and the target steering angle σtg is corrected in a direction approaching the neutral position within a range that does not exceed the neutral position. The MCU 401 sets a predetermined range on the left and right including the neutral position as the correction tolerance range, and can allow the target steering angle σtg to be corrected to slightly exceed the neutral position.

[0036] After setting the correction steering angle σ_c in step S504 or step S505, the MCU 401 proceeds to step S506, where it corrects the target steering angle σtg_a with the correction steering angle σ_c according to Equation 5 to obtain the final target steering angle σtg. Then, the MCU 401 outputs a control signal to the steering actuator 304 to set the steering angle σ of the front wheels 101, 102 to the target steering angle σtg.

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[0037] According to equation 5, the absolute value of the target steering angle σtg_a corresponding to the operating angle θ of the steering wheel 301 is subtracted by the absolute value of the correction steering angle σ_c, and the result of multiplying the subtraction result by the sign of the target steering angle σtg_a indicating the steering angle direction is set to the final target steering angle σtg. In this way, in an oversteer state in which the actual yaw rate γ is greater than the estimated yaw rate γi, the MCU 401 performs steering control to return the steering angle σ of the front wheels 101, 102 to near the neutral position regardless of the operation angle θ of the steering wheel 301.

[0038] According to this steering control, it is possible to prevent the vehicle behavior from deteriorating while suppressing the driver's sense of discomfort. In other words, when the steering angle σ of the front wheels 101, 102 changes beyond the neutral position due to steering angle control based on a comparison between the actual yaw rate γ and the estimated yaw rate γi, the vehicle enters a counter-steer state in which the steering angle σ of the front wheels 101, 102 points in the opposite direction even though the driver is operating the vehicle in the turning direction, and furthermore, the driver is unable to recognize that the vehicle is in a counter-steer state. Therefore, operating the steering wheel 301 by the driver in such a state may give the driver an uncomfortable feeling and may cause confusion in the driver's steering operation.

[0039] In response to this, the MCU 401 corrects the target steering angle σtg within a range that does not exceed the neutral position, thereby preventing the direction in which the driver operates the steering wheel 301 from being reversed to the direction in which the front wheels 101, 102 are steered. Therefore, the MCU 401 can suppress an increase in the yaw rate and prevent the vehicle behavior from deteriorating while minimizing the driver's sense of discomfort.

[0040] Furthermore, even if the driver performs an operation to change the operating angle θ of the steering wheel 301 after starting to modify the target steering angle σtg based on the yaw rate difference, the MCU 401 continues to modify the target steering angle σtg based on the yaw rate difference until the yaw rate difference falls below the threshold value α (in other words, until the yaw rate difference converges). Therefore, even if the driver senses that the vehicle 100 is oversteering and turns the steering wheel 301 in the opposite direction to the turning direction, if the operation is insufficient and the yaw rate difference does not decrease, the MCU 401 will intervene to correct the steering angle σ, thereby enabling the yaw rate difference to converge quickly.

[0041] Then, when the yaw rate difference decreases due to the correction of the target steering angle σtg (in other words, when the yaw rate difference converges), the MCU 401 sets the correction steering angle σ_c to zero, thereby restoring the steering angle σ of the front wheels 101, 102 to a state in which it is controlled to an angle corresponding to the operating angle θ of the steering wheel 301. Therefore, after the yaw rate difference has converged, the steering angle is controlled to correspond to the operation angle θ of the steering wheel 301, thereby suppressing any sense of discomfort felt by the driver.

[0042] In the present invention, the steering device 305 is controlled to perform steering control to prevent the vehicle behavior from deteriorating. Therefore, the steering angle of the wheels can be actually changed, and the convergence of the yaw rate difference can be achieved more quickly than in the case where the yaw rate difference is converged by controlling the braking device.

[0043] FIG. 3 is a time chart showing changes in the steering angle θ of the steering wheel 301, the steering angle σ of the front wheels 101, 102, and the yaw rate when the MCU 401 performs control to correct the steering angle σ of the front wheels 101, 102 based on a comparison between the actual yaw rate γ and the estimated yaw rate γi.

[0044] At time t1 in FIG. 3, when the actual yaw rate γ becomes larger than the estimated yaw rate γi, the MCU 401 starts corrective control of the steering angle σ according to the yaw rate difference, and performs control to return the steering angle σ of the front wheels 101, 102 to near the neutral position. This correction control of the steering angle σ prevents an increase in the actual yaw rate γ and reduces the yaw rate difference. When the yaw rate difference converges at time t2, the MCU 401 stops the correction control of the steering angle σ according to the yaw rate difference and returns to a state in which the steering angle is controlled according to the operating angle of the steering wheel 301.

[0045] In addition, when the actual yaw rate γ is larger than the estimated yaw rate γi and the driver turns the steering wheel 301 in the direction opposite to the turning direction, the MCU 401 can correct the target steering angle σtg beyond the neutral position to the opposite side by canceling the processing of Equation 4. In other words, when the driver senses that the vehicle 100 is oversteering and operates the steering wheel 301 in the direction opposite to the turning direction, even if the MCU 401 corrects the target steering angle σtg beyond the neutral position to the opposite side, the driver's sense of discomfort is reduced and the driver's operation of the steering wheel 301 is assisted.

[0046] Therefore, the MCU 401 outputs a control signal to the steering actuator 304 to turn the steering angle σ of the front wheels 101, 102 beyond the neutral position to the opposite side in accordance with the direction of operation of the steering wheel 301 by the driver. On the other hand, when the actual yaw rate γ is larger than the estimated yaw rate γi, if the driver is turning the steering wheel 301 in the same direction as the turning direction or is keeping the steering angle θ of the steering wheel 301 constant, the MCU 401 performs the processing of Equation 4 to prevent the target steering angle σtg from being corrected beyond the neutral position to the opposite side.

[0047] Furthermore, the condition under which the MCU 401 cancels the correction control of the target steering angle σtg based on the correction steering angle σ_c and returns to steering control based on the target steering angle σtg_a corresponding to the operation amount of the steering wheel 301 is not limited to the convergence of the yaw rate difference. For example, the MCU 401 determines the target steering angle σtg_a when the actual yaw rate γ becomes larger than the estimated yaw rate γi and starts to correct the target steering angle σtg based on the yaw rate difference as the reference target steering angle σtg_ab, and then the MCU 401 corrects the reference target steering angle σtg_ab with the correction steering angle σ_c to obtain the target steering angle σtg.

[0048] Then, when the target steering angle σtg obtained by correcting the reference target steering angle σtg_ab using the corrective steering angle σ_c becomes equal to the target steering angle σtg_a based on the operation amount of the steering wheel 301, the MCU 401 cancels the correction control of the target steering angle σtg using the corrective steering angle σ_c and returns to steering control in which the target steering angle σtg_a is unchanged as the target steering angle σtg. In other words, after starting correction control of the target steering angle σtg using the correction steering angle σ_c, when the steering angle σ of the front wheels 101, 102 becomes a value corresponding to the operating angle θ of the steering wheel 301, the MCU 401 can switch to outputting a control signal to the steering actuator 304 based on the operating angle of the steering wheel 301.

[0049] For example, after the MCU 401 starts corrective control of the target steering angle σtg using the correction steering angle σ_c based on the occurrence of a yaw rate difference, if the driver senses an oversteer state and operates the steering wheel 301, causing the steering angle σ of the front wheels 101, 102 to reach a value corresponding to the operating angle θ of the steering wheel 301, the steering angle σ will then be controlled to a value corresponding to the operating angle θ of the steering wheel 301.

[0050] According to this configuration, the MCU 401 corrects the target steering angle σtg based on the occurrence of a yaw rate difference, thereby suppressing an increase in the yaw rate from the beginning of the occurrence of the yaw rate difference, and also, when the driver senses the oversteer state late, operates the steering wheel 301, a smooth transition can be made to a state in which the steering angle σ is controlled in accordance with the original operating angle of the steering wheel 301. In addition, if the yaw rate difference converges before the steering angle σ of the front wheels 101, 102 reaches a value corresponding to the operating angle θ of the steering wheel 301, the MCU 401 cancels the correction control of the target steering angle σtg using the correction steering angle σ_c based on the convergence of the yaw rate difference.

[0051] The technical ideas explained in the above embodiments can be used in appropriate combinations 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 idea and teachings of the present invention.

[0052] For example, the steer-by-wire steering device 300 may be a steering device equipped with a backup mechanism that mechanically couples the steering wheel 301 and the front wheels 101, 102 with a clutch or the like. Furthermore, the reaction force actuator 302 or the steering actuator 304 is not limited to an electric motor, but may be, for example, a steering device that uses a solenoid as an actuator. Furthermore, the steering operation input member is not limited to the steering wheel 301, and the steering device may employ, for example, a joystick as the steering operation input member.

[0053] In addition, the MCU 401 determines the threshold value α of the difference between the actual yaw rate γ and the estimated yaw rate γi and the control gain K (V) can be changed based on the coefficient of friction of the road surface on which the vehicle 100 is traveling, the vehicle's load weight, the degree of tire wear, the vehicle speed, the curvature of the curve, the driver's driving proficiency, and the like. In other words, when the vehicle 100 is in a condition that makes it easy for the vehicle 100 to oversteer or when the driver has low driving proficiency, the MCU 401 can start correcting the steering angle σ based on the yaw rate difference at an earlier timing and / or can increase the correction range of the steering angle σ relative to the yaw rate difference. [Explanation of symbols]

[0054] 100...vehicle, 101, 102...front wheels (steering wheels), 200...steering system, 300...steering device (steer-by-wire), 301...steering wheel (steering operation input member), 303...steering member, 304...steering actuator, 305...steering device, 400...control device, 401...MCU (control unit), 407...yaw rate sensor, 411...operation angle sensor, 412...steering angle sensor

Claims

1. A steering device for a vehicle, the steering device including a steering operation input member and a steering actuator that applies a steering force to wheels of the vehicle, the steering device being configured to be able to independently control the steering angle of the wheels in response to an operation amount of the steering operation input member, A control device for a steering device, comprising: a control unit that outputs a control signal to the steering actuator based on a physical quantity related to an operation amount of the steering operation input member, The control unit A physical quantity relating to an actual yaw rate of the vehicle is acquired; acquiring a physical quantity related to an estimated yaw rate based on an operation amount of the steering operation input member and a running state of the vehicle; when the physical quantity related to the actual yaw rate is greater than the physical quantity related to the estimated yaw rate, a control signal for returning the steering angle of the wheels to a neutral position is output to the steering actuator regardless of the operation amount of the steering operation input member. A control device for a steering device.

2. 2. The steering device control device according to claim 1, The control unit when the steering angle of the wheels reaches a value corresponding to the operation amount of the steering operation input member, switching is performed so that a control signal is output to the steering actuator based on the operation amount of the steering operation input member. A control device for a steering device.

3. A steering device for a vehicle, the steering device including a steering operation input member and a steering actuator that applies a steering force to wheels of the vehicle, the steering device being configured to be able to independently control the steering angle of the wheels in response to an operation amount of the steering operation input member, A control device for a steering device, comprising: a control unit that outputs a control signal to the steering actuator based on a physical quantity related to an operation amount of the steering operation input member, The control unit A physical quantity relating to an actual yaw rate of the vehicle is acquired; acquiring a physical quantity related to an estimated yaw rate based on an operation amount of the steering operation input member and a running state of the vehicle; when the physical quantity related to the actual yaw rate is greater than the physical quantity related to the estimated yaw rate, a control signal is output to the steering actuator to displace the steering angle of the wheels beyond the neutral position to the opposite side in accordance with the operation direction of the steering operation input member, regardless of the operation amount of the steering operation input member. A control device for a steering device.

4. A method for controlling a steering device executed by a control device mounted on a vehicle equipped with a steering device, comprising: the steering device includes a steering operation input member and a steering actuator that applies a steering force to wheels of the vehicle, and is configured to be able to independently control the steering angle of the wheels in response to an operation amount of the steering operation input member; The steering device control method includes: acquiring a physical quantity related to an actual yaw rate of the vehicle; acquiring a physical quantity related to an estimated yaw rate based on an operation amount of the steering operation input member and a running state of the vehicle; when the physical quantity related to the actual yaw rate is greater than the physical quantity related to the estimated yaw rate, outputting a control signal to the steering actuator to return the steering angle of the wheels to a neutral position regardless of the operation amount of the steering operation input member; Including, A method for controlling a steering device.

5. A method for controlling a steering device executed by a control device mounted on a vehicle equipped with a steering device, comprising: the steering device includes a steering operation input member and a steering actuator that applies a steering force to wheels of the vehicle, and is configured to be able to independently control the steering angle of the wheels in response to an operation amount of the steering operation input member; The steering device control method includes: acquiring a physical quantity related to an actual yaw rate of the vehicle; acquiring a physical quantity related to an estimated yaw rate based on an operation amount of the steering operation input member and a running state of the vehicle; when the physical quantity related to the actual yaw rate is greater than the physical quantity related to the estimated yaw rate, outputting a control signal to the steering actuator to displace the steering angle of the wheels beyond a neutral position to an opposite side in accordance with an operation direction of the steering operation input member, regardless of an operation amount of the steering operation input member; Including, A method for controlling a steering device.

6. a steering operation input member attached to the vehicle; a steering device including a steering actuator that applies a steering force to wheels of the vehicle; a control device including a control unit that outputs a control signal to the steering actuator based on a physical quantity related to an operation amount of the steering operation input member; and A steering system configured to be able to independently control the steering angle of the wheels in response to the operation amount of the steering operation input member, The control unit A physical quantity relating to an actual yaw rate of the vehicle is acquired; acquiring a physical quantity related to an estimated yaw rate based on an operation amount of the steering operation input member and a running state of the vehicle; when the physical quantity related to the actual yaw rate is greater than the physical quantity related to the estimated yaw rate, a control signal for returning the steering angle of the wheels to a neutral position is output to the steering actuator regardless of the operation amount of the steering operation input member. Steering system.

7. a steering operation input member attached to the vehicle; a steering device including a steering actuator that applies a steering force to wheels of the vehicle; a control device including a control unit that outputs a control signal to the steering actuator based on a physical quantity related to an operation amount of the steering operation input member; and A steering system configured to be able to independently control the steering angle of the wheels in response to the operation amount of the steering operation input member, The control unit A physical quantity relating to an actual yaw rate of the vehicle is acquired; acquiring a physical quantity related to an estimated yaw rate based on an operation amount of the steering operation input member and a running state of the vehicle; when the physical quantity related to the actual yaw rate is greater than the physical quantity related to the estimated yaw rate, a control signal is output to the steering actuator to displace the steering angle of the wheels beyond the neutral position to the opposite side in accordance with the operation direction of the steering operation input member, regardless of the operation amount of the steering operation input member. Steering system.

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