Steering control device

Abstract

This invention relates to a steering control device. The steering control device includes a first processor (63E, 63F, 63G), a second processor (63H), a third processor (63J, 63K, 63L), and a fourth processor (63N). The first processor calculates a torque command value based on the difference between a target pinion angle and a pinion angle. The second processor calculates a compensation value to compensate for the resistance of the steering mechanism based on the difference between a target pinion angular velocity and a pinion angular velocity. The third processor limits the range of variation of the torque command value based on a limit for the torque command value, and also limits the range of variation of the compensation value based on a limit for the compensation value. The fourth processor calculates the steering torque command value by subtracting the compensation value from the torque command value. The third processor changes the limit value based on the vehicle's driving state.

Description

Technical Field

[0001] This invention relates to a steering control device. Background Technology

[0002] In related technologies, there exists an electric power steering system that assists steering wheel operation by applying the torque of a motor as a power assist to the steering shaft. The control unit of the electric power steering system calculates the current command value for the motor based on the steering torque detected by a torque sensor. The control unit then controls the power supply to the motor based on the current command value. Therefore, the motor generates torque based on the steering torque.

[0003] Recently, a so-called steer-by-wire system has emerged, in which the power transmission between the steering wheel and the steering wheels is cut off. This steering system includes: a reaction motor that generates a steering reaction force applied to the steering shaft; and a steering motor that generates a steering force to turn the steering wheels. The control unit of the steering system generates the steering reaction force by controlling the power supply to the reaction motor, and turns the steering wheels by controlling the power supply to the steering motor.

[0004] For example, the steering mechanism described in Japanese Unexamined Patent Application Publication No. 2020-82915 (JP 2020-82915A) can perform emergency avoidance support control. The steering mechanism's control unit controls the motor based on information from the main control unit. When there is a concern that the vehicle may collide with an obstacle in its direction of travel, the main control unit calculates a target steering angle to move the vehicle in the direction free of the obstacle. The steering mechanism's control unit performs feedback control to match the actual steering angle with the target steering angle.

[0005] The steering control unit sets the feedback gain value for emergency avoidance support control to, for example, a value greater than that for normal driving. This is because emergency avoidance support control requires a higher response time than normal driving control. The feedback control is PID control and includes proportional, integral, and derivative control. The feedback gain includes proportional gain, integral gain, and derivative gain.

[0006] The steering control unit calculates the difference between the target steering angle calculated by the main control unit and the actual steering angle. The control unit calculates the steering wheel angle based on the motor rotation angle detected by the rotation angle sensor. The control unit calculates the motor current command value by adding the value obtained by multiplying the proportionally processed difference by a proportional gain, the value obtained by multiplying the integrally processed difference by an integral gain, and the value obtained by multiplying the differentially processed difference by a differential gain. Summary of the Invention

[0007] The steering control unit can be configured to perform various types of compensatory control on the current command value to achieve superior steering feel. An example of compensatory control is damping control. The control unit, for instance, calculates a compensation value based on the steering speed to compensate for steering resistance and uses the calculated compensation value to correct the current command value.

[0008] The steering control unit can be configured to set limits to restrict the range of variation of values ​​calculated by performing proportional control, integral control, derivative control, and damping control. The limits include an upper and lower limit for each value. When an excessive value greater than the limit is calculated by performing control, the control unit limits the calculated excessive value to an appropriate value equal to or less than the limit.

[0009] For example, based on the limit value, the following problem exists. That is, for example, when performing an emergency avoidance maneuver via the steering wheel, the value calculated by proportional control or derivative control and the compensation value calculated by damping control may cancel each other out. Therefore, the steering wheels may not be able to be turned properly. Therefore, it is necessary to turn the steering wheels properly according to the steering wheel's steering operation state.

[0010] According to one aspect of this disclosure, a steering control device is provided for controlling a steering motor that generates steering force for the steering wheels of a vehicle. The steering control device calculates a target angle of a rotating member that rotates with the steering wheel operation based on the steering state of the steering wheel, and calculates a steering torque command value for the steering motor by executing feedback control, such that the actual angle of the rotating member matches the target angle. The steering control device includes: a first processor configured to calculate the torque command value based on the difference between the target angle and the actual angle; a second processor configured to calculate a compensation value for the torque command value based on a target angular velocity or the actual angular velocity of the rotating member, the compensation value acting in the opposite direction to the torque command value; a third processor configured to perform a limiting process to limit the range of variation of the torque command value based on a limit value of the torque command value, and to limit the range of variation of the compensation value based on a limit value of the compensation value; and a fourth processor configured to calculate the steering torque command value using the torque command value after the limiting process and the compensation value after the limiting process. The third processor is configured to increase the limit value of the torque command value and the limit value of the compensation value based on the driving state of the vehicle.

[0011] For example, when the limit is set to a fixed value, the torque command value and the compensation value may be limited to the same value depending on the vehicle's driving conditions. In this case, there is a problem that the torque command value and the compensation value may cancel each other out.

[0012] With this configuration, the limits for the torque command value and the compensation value are increased separately according to the vehicle's driving conditions. Since the ranges of variation for the torque command value and the compensation value are expanded independently based on the vehicle's driving conditions, it is possible to avoid limiting the torque command value and the compensation value to the same value, or to prevent them from canceling each other out. Therefore, the steering wheels can be turned appropriately according to the steering wheel's steering input.

[0013] In the steering control device, the third processor can be configured to increase the limit of the torque command value and the limit of the compensation value when the value of the vehicle state parameter reflecting the vehicle's driving state is greater than a predetermined threshold.

[0014] With this configuration, when the vehicle state parameter value reflecting the vehicle's driving state exceeds a threshold, the limits for the torque command value and the compensation value are increased. Since the range of variation for the torque command value and the range of variation for the compensation value are expanded independently, it is possible to avoid limiting the torque command value and the compensation value to the same value. Therefore, the cancellation of the torque command value and the compensation value can be suppressed. Thus, the steering wheel can be appropriately steered according to the steering wheel's steering input state.

[0015] In the steering control unit, the third processor can be configured to increase the limit of the torque command value and the limit of the compensation value to the same value when the value of the vehicle state parameter is greater than the threshold.

[0016] With this configuration, when the vehicle state parameter value exceeds a threshold, the limits for the torque command value and the compensation value are increased to the same value. Therefore, the range of variation for the torque command value and the range of variation for the compensation value are expanded independently. Since limiting the torque command value and the compensation value to the same value is avoided, the cancellation of the torque command value and the compensation value is prevented. Therefore, the steering wheel can be turned appropriately according to the steering wheel's steering input state.

[0017] In the steering control unit, the third processor can be configured to increase the limits of the torque command value and the compensation value to different values ​​when the value of the vehicle state parameter is greater than the threshold.

[0018] With this configuration, when the vehicle state parameter value exceeds a threshold, the limits for the torque command value and the compensation value are increased to different values. Therefore, the range of variation for the torque command value and the range of variation for the compensation value are expanded independently. Since limiting the torque command value and the compensation value to the same value is avoided, the cancellation of the torque command value and the compensation value is prevented. Therefore, the steering wheel can be turned appropriately according to the steering wheel's steering input state.

[0019] In the steering control unit, the limit of the torque command value can be greater than the limit of the compensation value. With this configuration, when the value of the vehicle state parameter is greater than the threshold, the torque command value can be better reflected in the steering torque command value.

[0020] In the steering control device, the third processor can be configured to increase the limit of the torque command value and the limit of the compensation value as the value of the vehicle state parameter increases, when the value of the vehicle state parameter is greater than the threshold.

[0021] This configuration allows for the appropriate adjustment of limits based on the values ​​of vehicle status parameters. In the steering control unit, these vehicle status parameters can be the vehicle speed detected by onboard sensors, the yaw rate, the ratio of the actual angle to the target angle, or the ratio of the actual angular velocity to the target angular velocity. The vehicle's driving state is reflected in these values.

[0022] In the steering control unit, the third processor can be configured to determine whether an emergency avoidance maneuver using the steering wheel may be performed when the value of a vehicle state parameter is greater than a threshold.

[0023] This configuration allows for the determination of whether an emergency avoidance maneuver using the steering wheel is possible by comparing vehicle state parameters with thresholds. When an emergency avoidance maneuver is performed, the steering wheels can be turned appropriately based on the steering wheel's steering input status.

[0024] In the steering control device, the third processor may include a gradient processor configured to gradually change the limits of the torque command value and the limits of the compensation value over time by performing gradient processing on the limits of the torque command value and the limits of the compensation value.

[0025] This configuration avoids sudden changes in the limits, thus suppressing sudden changes in the torque command value and compensation value, as well as sudden changes in the steering torque command value. Therefore, sudden changes in the steering force generated by the steering motor can be suppressed.

[0026] In the steering control device, the torque command value may include a first torque command value having a value proportional to the difference and a second torque command value having a value proportional to the integral of the difference. The first torque command value is calculated by performing a proportional operation on the difference, and the second torque command value is calculated by performing an integral operation on the difference. In this case, a third processor may be configured to limit the range of variation of the sum of the first and second torque command values ​​based on a limit.

[0027] With this configuration, the sum of the first and second torque command values, as well as the limit of the compensation value, increases according to the vehicle's driving conditions. Since the range of variation of the sum value and the range of variation of the compensation value expand independently, it is possible to avoid limiting the sum value and the compensation value to the same value. Therefore, it is possible to prevent the sum value and the compensation value from canceling each other out. Thus, the steering wheel can be appropriately steered according to the steering wheel's steering input.

[0028] In the steering control device, the torque command value may include a first torque command value having a value proportional to the difference and a second torque command value having a value proportional to the integral of the difference. The first torque command value is calculated by performing a proportional operation on the difference, and the second torque command value is calculated by performing an integral operation on the difference. In this case, a third processor may be configured to limit the range of variation of the first torque command value based on a limit of the first torque command value, and to limit the range of variation of the second torque command value based on a limit of the second torque command value.

[0029] With this configuration, the limits for the first torque command value, the second torque command value, and the compensation value increase according to the vehicle's driving conditions. Since the ranges for variation of the first torque command value, the second torque command value, and the compensation value are expanded independently, it is possible to avoid limiting these values ​​to the same level. Therefore, it is possible to prevent the first torque command value and the compensation value from canceling each other out, as well as the second torque command value and the compensation value from canceling each other out. Therefore, the steering wheels can be appropriately steered according to the steering wheel's steering input.

[0030] Using the steering control device according to the invention, the steering wheel can be turned appropriately according to the steering operation state of the steering wheel. Attached Figure Description

[0031] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals denote the same elements, and in the drawings:

[0032] Figure 1 This is a diagram showing the configuration of the steering operation device in which the steering control device according to the first embodiment is installed;

[0033] Figure 2 This is a block diagram showing the reaction control device and steering control device according to the first embodiment;

[0034] Figure 3 This is a block diagram showing a pinion angle feedback controller according to a first embodiment;

[0035] Figure 4 This is a block diagram showing the first to third protection processors according to the first embodiment;

[0036] Figure 5 It is a graph showing how the torque command value changes over time according to the comparison example;

[0037] Figure 6 This is a graph showing a first example of how the torque command value changes over time according to the first embodiment;

[0038] Figure 7 This is a graph showing a second example of how the torque command value changes over time according to the first embodiment;

[0039] Figure 8 This is a block diagram showing a pinion angle feedback controller according to a second embodiment;

[0040] Figure 9 It is a graph showing the first mapping used by the setting unit according to the third embodiment; and

[0041] Figure 10 This is a graph showing the second mapping used by the setting unit according to the second embodiment. Detailed Implementation

[0042] Overall configuration

[0043] The steering control device according to the first embodiment will be described below. Figure 1 As shown, the control target of the steering control device 1 is the steer-by-wire steering device 2. The steering control device 2 includes a steering mechanism 3 and a steering mechanism 4. The steering mechanism 3 is a mechanism component used by the driver to steer using the steering wheel 5. The steering mechanism 4 is a mechanism component that steers the vehicle's steering wheels 6 according to the steering operation of the steering wheel 5. The steering control device 1 includes a reaction control device 1A and a steering control device 1B. The control target of the reaction control device 1A is the steering mechanism 3. The reaction control device 1A performs reaction control. The control target of the steering control device 1B is the steering mechanism 4. The steering control device 1B performs steering control.

[0044] The steering mechanism 3 includes a steering shaft 11, a reaction motor 12, and a reduction gear 13. The steering wheel 5 is connected to the steering shaft 11 so that they can rotate together. The reaction motor 12 is the source of the steering reaction force applied to the steering shaft 11. The steering reaction force is a force in the opposite direction to the steering direction of the steering wheel 5. For example, the reaction motor 12 is a three-phase brushless motor. The reduction gear 13 reduces the rotation of the reaction motor 12 and transmits the reduced rotation to the steering shaft 11.

[0045] The steering mechanism 4 includes a pinion shaft 21, a steering shaft 22, and a housing 23. The housing 23 rotatably supports the pinion shaft 21. The housing 23 houses the steering shaft 22, allowing it to move translationally. The pinion shaft 21 is configured to connect to the steering shaft 22. The pinion teeth 21a of the pinion shaft 21 mesh with the rack teeth 22a of the steering shaft 22. A tie rod 25 is connected to both ends of the steering shaft 22 via a rack end 24 including a ball joint. The top end of the tie rod 25 is connected to a steering knuckle (not shown) fitted into the steering wheel 6.

[0046] The steering mechanism 4 includes a steering motor 31, a power transmission mechanism 32, and a conversion mechanism 33. The steering motor 31 is the source of the steering force applied to the steering shaft 22. The steering force is the force used to turn the steering wheels 6. The steering motor 31 is, for example, a three-phase brushless motor. The power transmission mechanism 32 is, for example, a belt-type power transmission mechanism. The power transmission mechanism 32 transmits the rotation of the steering motor 31 to the conversion mechanism 33. The conversion mechanism 33 is, for example, a ball screw mechanism. The conversion mechanism 33 converts the rotation transmitted from the power transmission mechanism 32 into axial movement of the steering shaft 22.

[0047] When the steering shaft 22 moves axially, the steering angle θ of the steering wheel 6... w Change. Because the pinion teeth 21a of the pinion shaft 21 mesh with the rack teeth 22a of the steering shaft 22, the pinion shaft 21 rotates as the steering shaft 22 moves. The pinion shaft 21 is a rotating component that rotates with the steering operation of the steering wheel 6.

[0048] The reaction control device 1A controls the operation of the reaction motor 12. The reaction control device 1A includes a processing circuit having one of the following configurations: A1, A2, and A3. A1. One or more processors operating according to a computer program as software. The processors include a central processing unit (CPU) and memory.

[0049] A2. One or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs) that perform at least some of various processes. ASICs include CPUs and memory.

[0050] A3. Hardware circuitry that combines configurations A1 and A2. Memory is a computer-readable medium that stores programs describing the processing or commands of a computer. In this embodiment, the computer is a CPU. Memory includes random access memory (RAM) and read-only memory (ROM). The CPU performs various types of control by executing programs stored in memory within predetermined operating cycles.

[0051] The reaction control device 1A receives detection results from onboard sensors. These sensors include a vehicle speed sensor 41, a torque sensor 42, and a rotation angle sensor 43. The vehicle speed sensor 41 detects the vehicle speed V. Vehicle speed V is a vehicle state quantity reflecting the vehicle's driving state. The torque sensor 42 is disposed in the steering shaft 11. The connection portion of the torque sensor 42 relative to the reduction gear 13 in the steering shaft 11 is located on the steering wheel 5 side. The torque sensor 42 detects the steering torque Th applied to the steering shaft 11. The steering torque Th is calculated based on the amount of torsion of the torsion bar 42a disposed in the steering shaft 11. The rotation angle sensor 43 is disposed in the reaction motor 12. The rotation angle sensor 43 detects the rotation angle θ of the reaction motor 12. a .

[0052] For example, when the steering wheel 5 is turned to the right, the steering torque Th and rotation angle θ of the reaction motor 12... a It has a positive value, and when the steering wheel 5 is turned to the left, the steering torque Th and rotation angle θ of the reaction motor 12 are positive. a It has negative values.

[0053] The reaction control device 1A uses the detection results from the vehicle speed sensor 41, torque sensor 42, and rotation angle sensor 43 to control the operation of the reaction motor 12. The reaction control device 1A controls the power supply to the reaction motor 12, so that the reaction motor 12 generates a steering reaction force corresponding to the steering torque Th.

[0054] Steering control device 1B controls the operation of steering motor 31. Steering control device 1B includes a processing circuit similar to reaction control device 1A, having one of the three configurations A1, A2, and A3 described above.

[0055] The steering control unit 1B receives detection results from onboard sensors. These sensors include a rotation angle sensor 44, which is located within the steering motor 31. The rotation angle sensor 44 detects the rotation angle θ of the steering motor 31. b For example, when the steering wheel 5 is turned to the right, the rotation angle θ of the steering motor 31... b It has a positive value, and when the steering wheel 5 is turned to the left, the rotation angle θ of the steering motor 31 is... b It has negative values.

[0056] The steering control unit 1B uses the detection results from the rotation angle sensor 44 to control the operation of the steering motor 31. The steering control unit 1B controls the power supply to the steering motor 31 so that the steering wheel 6 is turned according to the steering operation state of the steering wheel 5.

[0057] Configuration of reaction control device 1A

[0058] The configuration of the reaction control device 1A will be described below. For example... Figure 2 As shown, the reaction control device 1A includes a steering angle calculation unit 51, a reaction torque command value calculation unit 52, and a power supply controller 53.

[0059] Steering angle calculation unit 51 is based on the rotation angle θ of reaction motor 12 detected by rotation angle sensor 43. a The steering angle θs of the steering wheel 5 is calculated. The reaction torque command value calculation unit 52 calculates the reaction torque command value T based on the steering torque Th and the vehicle speed V. * Reaction torque command value T * This is the target value of the steering reaction force generated by the reaction motor 12. The steering reaction force is a torque opposite to the steering direction of the steering wheel 5. The reaction torque command value T * The absolute value of increases as the absolute value of steering torque Th increases and the vehicle speed V decreases.

[0060] The power supply controller 53 supplies the reaction torque command value T to the reaction motor 12. * The corresponding power supply. Specifically, the power supply controller 53 is based on the reaction torque command value T. * The current command value for the reaction motor 12 is calculated. The power supply controller 53 uses a current sensor 54 installed in the power supply path to the reaction motor 12 to detect the current I flowing in the power supply path. a The value of current I. a The value is the value of the current supplied to the reaction motor 12. The power supply controller 53 calculates the current command value and the current I. a The difference between the values ​​is controlled, and the power supply to the reaction motor 12 is adjusted to eliminate the difference. Therefore, the reaction motor 12 generates a reaction torque command value T. * The corresponding torque.

[0061] Configuration of steering control device 1B

[0062] The configuration of the steering control unit 1B will be described below. For example... Figure 2 As shown, the steering control device 1B includes a pinion angle calculation unit 61, a target pinion angle calculation unit 62, a pinion angle feedback controller 63, and a power supply controller 64.

[0063] The pinion angle calculation unit 61 is based on the rotation angle θ of the steering motor 31 detected by the rotation angle sensor 43. b To calculate the pinion angle θp pinion angle θ p This refers to the rotation angle of the pinion shaft 21. The steering motor 31 and the pinion shaft 21 are interlocked with each other via the power transmission mechanism 32, the conversion mechanism 33, and the steering shaft 22. Therefore, the rotation angle θ of the steering motor 31... b Angle θ with the pinion p There is a correlation between them. This correlation can be used based on the rotation angle θ of the steering motor 31. b Calculate the pinion angle θ p The pinion shaft 21 meshes with the steering shaft 22. Therefore, the pinion angle θ p There is also a correlation between the amount of movement and the steering shaft 22. That is, the pinion angle θ p It contains the steering angle θ of the steering wheel 6. w The value of .

[0064] The target pinion angle calculation unit 62 is based on the steering angle θ calculated by the steering angle calculation unit 51. s To calculate the target pinion angle θ p * The target pinion angle calculation unit 62 calculates the target pinion angle θ. p * This allows for the implementation of steering angle ratios set according to product specifications. The steering angle ratio is the steering angle θ. w With steering angle θ s than.

[0065] For example, the target pinion angle calculation unit 62 sets the steering angle ratio according to the vehicle's driving state, such as vehicle speed V, and calculates the target pinion angle θ based on the set steering angle ratio. p * The target pinion angle calculation unit 62 calculates the steering angle θ. w Relative to steering angle θ s The target pinion angle θ increases as the vehicle speed V decreases. p * The target pinion angle calculation unit 62 calculates the steering angle θ. w Relative to steering angle θ s The target pinion angle θ decreases as the vehicle speed V increases. p * The target pinion angle calculation unit 62 calculates the steering angle θ used to implement the steering angle ratio set according to the vehicle's driving state. s The correction angle is calculated by comparing the calculated correction angle with the steering angle θ. s The target pinion angle θ is calculated by adding them together based on the steering angle ratio.p * .

[0066] Based on product specifications, the target pinion angle calculation unit 62 can calculate the target pinion angle θ that ensures a steering angle ratio of "1:1" regardless of the vehicle's driving state. p * .

[0067] The pinion angle feedback controller 63 receives the target pinion angle θ calculated by the target pinion angle calculation unit 62. p * and the pinion angle θ calculated by pinion angle calculation unit 61 p The pinion angle feedback controller 63 uses the pinion angle θ... p Feedback control is used to calculate the steering torque command value T. p * This makes the pinion angle θ p Following the target pinion angle θ p * Steering torque command value T p * It is the command value of the torque generated by the steering motor 31, and the target value of the steering force.

[0068] The power supply controller 64 will be related to the steering torque command value T p * The corresponding power supply is sent to the steering motor 31. Specifically, the power supply controller 64 is based on the steering torque command value T. p * The power supply controller 64 calculates the current command value for the steering motor 31. It uses a current sensor 65 located in the power supply path to the steering motor 31 to detect the current I flowing in the power supply path. b The value of current I. b The value is the value of the current supplied to the steering motor 31. The power supply controller 64 calculates the current command value and the current I. b The difference between the values ​​is calculated, and the power supply to the steering motor 31 is controlled to eliminate the difference. Therefore, the steering motor 31 generates a steering torque command value T. p * The corresponding torque.

[0069] Configuration of pinion angle feedback controller 63

[0070] The configuration of the pinion angle feedback controller 63 will be described below. For example... Figure 3 As shown, the pinion angle feedback controller 63 includes a first subtractor 63A, a first differentiator 63B, a second differentiator 63C, and a second subtractor 63D.

[0071] The first subtractor 63A receives the target pinion angle θ calculated by the target pinion angle calculation unit 62. p * and the pinion angle θ calculated by pinion angle calculation unit 61 p The first subtractor 63A calculates the angle difference Δθ. p Angular difference Δθ p The target pinion angle θ p * Angle θ with the pinion p The difference between them.

[0072] The first differentiator 63B measures the target pinion angle θ calculated by the target pinion angle calculation unit 62. p * To calculate the angular velocity ω of the target pinion by performing differentiation. p * The second differentiator 63C measures the pinion angle θ calculated by the pinion angle calculation unit 61. p To calculate the angular velocity ω of the pinion by performing differentiation p .

[0073] The second subtractor 63D receives the target pinion angular velocity ω calculated by the first differentiator 63B. p * and the pinion angular velocity ω calculated by the second differentiator 63C p The second subtractor, 63D, calculates the angular velocity difference Δω. p Angular velocity difference Δω p The target pinion's angular velocity ω p * With the angular velocity ω of the pinion p The difference between them.

[0074] The pinion angle feedback controller 63 includes a proportional controller 63E, an integral controller 63F, a derivative controller 63G, and a damping controller 63H. The proportional controller 63E feeds the angle difference Δθ calculated by the first subtractor 63A. p Perform proportional calculations to calculate the value with angle difference Δθ. p The first torque command value T is proportional to the value of the first torque command value. p1 The proportional controller 63E measures the angle difference Δθ. p The first torque command value T is calculated by multiplying by the proportional gain. p1 The proportional gain is a constant that is tuned to achieve the control characteristics.

[0075] The integral controller 63F uses the angle difference Δθ calculated by the first subtractor 63A. pPerform integration to calculate the value with angle difference Δθ p The integral value is proportional to the second torque command value T p2 The integral controller 63F measures the angle difference Δθ. p The second torque command value T is calculated by integrating the integral over time and multiplying the integral value by the integral gain. p2 The integral gain is a constant that is tuned to achieve the desired control characteristics.

[0076] The differential controller 63G uses the angular velocity difference Δω calculated by the second subtractor 63D. p Perform differential operations to calculate the difference between the angular velocity and the angular velocity Δω. p The third torque command value T is proportional to the differential value. p3 The differential controller 63G measures the angular velocity difference Δω. p The third torque command value T is calculated by multiplying the time derivative by the derivative gain. p3 The differential gain is a constant that is tuned to achieve the desired control characteristics.

[0077] The damping controller 63H receives the pinion angular velocity ω calculated by the second differentiator 63C. p And based on the received pinion angular velocity ω p Calculate the fourth torque command value T p4 The fourth torque command value T p4 This is the compensation value used to compensate for the resistance of steering mechanism 4. Fourth torque command value T p4 This is to suppress the angular velocity ω of the pinion. p This is the compensation value calculated to suppress the steering angular velocity of steering wheel 6. Fourth torque command value T p4 This is for the first torque command value T p1 Second torque command value T P2 and the third torque command value T P3 The compensation value. The fourth torque command value T. p4 Mainly targeting the first torque command value T p1 The compensation value.

[0078] Fourth torque command value T p4 It is in relation to the first torque command value T p1 Second torque command value T p2 and the third torque command value T P3 The compensation value that acts in the opposite direction, or the first torque command value T. p1 Second torque command value T p2 and the third torque command value T p3 The sum of the values. Fourth torque command value T p4The third subtractor 63N, which will be described later, takes effect. Furthermore, the damping controller 63H can be based on the target pinion angular velocity ω calculated by the first differentiator 63B. p * To calculate the fourth torque command value T p4 .

[0079] The pinion angle feedback controller 63 includes a first adder 63I, a first protection processor 63J, a second protection processor 63K, and a third protection processor 63L. The first adder 63I receives a first torque command value T calculated by the proportional controller 63E. p1 and the second torque command value T calculated by the integral controller 63F p2 The first adder 63I inputs the first torque command value T. p1 Second torque command value T p2 The fifth torque command value T is calculated by adding them together. P5 Fifth torque command value T p5 It is the first torque command value T p1 Second torque command value T P2 The sum of values.

[0080] The first protection processor 63J receives the fifth torque command value T calculated by the first adder 63I. p5 The vehicle speed V is detected by vehicle speed sensor 41. The first protection processor 63J calculates the fifth torque command value T based on the vehicle speed V. p5 The limit. This limit includes the fifth torque command value T. p5 The upper and lower limits. The first protection processor 63J sets the fifth torque command value T based on the upper and lower limits. p5 Execution of limitation processing. The first protection processor 63J calculates the sixth torque command value T by executing limitation processing. p6 .

[0081] The first protection processor 63J will assign the fifth torque command value T. p5 Compare with the upper limit. When the fifth torque command value T p5 When the value exceeds the upper limit, the first protection processor 63J will set the fifth torque command value T. p5 The fifth torque command value T is limited to the upper limit. p5 Become the sixth torque command value T p6 .

[0082] The first protection processor 63J will assign the fifth torque command value T. p5 Compare with the lower limit. When the fifth torque command value T... p5 When the value is less than the lower limit, the first protection processor 63J will set the fifth torque command value T. p5Limit to the lower limit. The fifth torque command value T is limited to the lower limit. p5 Become the sixth torque command value T p6 .

[0083] When the fifth torque command value T p5 When the value is between the upper and lower limits, the fifth torque command value T is calculated by the first adder 63I. p5 Without any changes, it becomes the sixth torque command value T. p6 .

[0084] The second protection processor 63K receives the third torque command value T calculated by the differential controller 63G. p3 The vehicle speed V is detected by vehicle speed sensor 41. The second protection processor 63K calculates the third torque command value T based on the vehicle speed V. p3 The limit. This limit includes the third torque command value T. p3 The upper and lower limits. The second protection processor 63K bases the third torque command value T on the upper and lower limits. p3 The second protection processor 63K performs constraint processing to calculate the seventh torque command value T. p7 .

[0085] The third protection processor 63L receives the fourth torque command value T calculated by the damping controller 63H. p4 The vehicle speed V is detected by vehicle speed sensor 41. The third protection processor 63L calculates the fourth torque command value T based on the vehicle speed V. p4 The limit. This limit includes the fourth torque command value T. p4 The upper and lower limits. The third protection processor 63L adjusts the fourth torque command value T based on the upper and lower limits. p4 The third protection processor 63L performs constraint processing to calculate the eighth torque command value T. p8 .

[0086] The pinion angle feedback controller 63 includes a second adder 63M, a third subtractor 63N, and a fourth protection processor 63O. The second adder 63M receives the sixth torque command value T calculated by the first protection processor 63N. p6 and the seventh torque command value T calculated by the second protection processor 63K p7 The second adder 63M uses the sixth torque command value T. p6 and the seventh torque command value T p7 The ninth torque command value T is calculated by adding them together. p9 .

[0087] The third subtractor 63N receives the ninth torque command value T calculated by the second adder 63M. p9and the eighth torque command value T calculated by the third protection processor 63L p8 The third subtractor 63N is activated by the ninth torque command value T. p9 Subtract the eighth torque command value T p8 To calculate the tenth torque command value T p10 .

[0088] The fourth protection processor 63O receives the tenth torque command value T calculated by the third subtractor 63N. p10 The fourth protection processor 63O includes the tenth torque command value T. p10 The limit. This limit includes the tenth torque command value T. p10 The upper and lower limits. The fourth protection processor 63O bases the tenth torque command value T on the upper and lower limits. p10 The fourth protection processor 63O performs constraint processing to calculate the final steering torque command value T for controlling the steering motor 31. p * .

[0089] Target pinion angle θ p * The target angle corresponds to the rotating component that rotates with the operation of the steering wheel 6. Pinion angle θ p This corresponds to the actual angle of the rotating component. The angular velocity ω of the target pinion. p * The target angular velocity corresponds to the rotating component. The angular velocity ω of the pinion. p Corresponding to the actual angular velocity of the rotating component. The proportional controller 63E, integral controller 63F, and derivative controller 63G constitute the first processor. The damping controller 63H constitutes the second processor. The first protection processor 63J, the second protection processor 63K, and the third protection processor 63L constitute the third processor. The third subtractor 63N constitutes the fourth processor.

[0090] Configuration of the first to third protection processors 63J, 63K and 63L

[0091] The configurations of the first to third protection processors 63J, 63K, and 63L will be described below. The first to third protection processors 63J, 63K, and 63L have essentially the same configuration.

[0092] like Figure 4 As shown, the first protection processor 63J includes a setting unit 71. The setting unit 71 includes a first determining unit 71A and a first switch 71B. The first determining unit 71A receives the vehicle speed V detected by the vehicle speed sensor 41 and a first vehicle speed threshold V stored in the memory. th1 The first vehicle speed threshold Vth1 This setting pertains to the speed of vehicles that might use steering wheel 5 to perform emergency avoidance maneuvers. First vehicle speed threshold V th1 This refers to the vehicle speed within the so-called low-speed range, and is set to, for example, 20 km / h. This is because, for example, when a vehicle is traveling at a very low speed range equal to or less than 5 km / h, the likelihood of performing an emergency avoidance maneuver is low. Furthermore, the low-speed range is, for example, a speed range equal to or greater than 0 km / h and less than 40 km / h.

[0093] The first determining unit 71A is based on the vehicle speed V and the first vehicle speed threshold V. th1 The comparison result determines whether an emergency avoidance maneuver is possible. The first determining unit 71A bases the vehicle speed V on the comparison between the vehicle speed V and a first vehicle speed threshold V. th1 The comparison result is used to set the value of the first flag F1. When the vehicle speed V is less than the first vehicle speed threshold V... th1 When the first determining unit 71A determines that an emergency avoidance maneuver is unlikely, it sets the value of the first flag F1 to "0". When the vehicle speed V is greater than the first vehicle speed threshold V... th1 At that time, the first determining unit 71A determines that an emergency avoidance operation may be performed and sets the value of the first flag F1 to "1".

[0094] The first switch 71B receives a first setting value G1 stored in memory and a second setting value G2 stored in memory as data input. The first setting value G1 is a fixed value, for example, "1". The second setting value G2 is a value specific to the first protection processor 63J. The second setting value G2 is a fixed value and is set to a value greater than "1".

[0095] The first switch 71B receives the value of the first flag F1 set by the first determining unit 71A as a control input. The first switch 71B sets the value of the third setting value G3 based on the value of the first flag F1. When the value of the first flag F1 is "0", the first switch 71B selects the first setting value G1 (referred to as "1" in this document) as the third setting value G3. When the value of the first flag F1 is "1", the first switch 71B sets the second setting value G2 as the third setting value G3.

[0096] The first protection processor 63J includes a second determining unit 72, a second switch 73, a gradient processor 74, a multiplier 75, a sign inversion processor 76, and a limit processor 77. The second determining unit 72 receives the vehicle speed V detected by the vehicle speed sensor 41 and a second vehicle speed threshold V stored in the memory. th2 The second vehicle speed threshold V th2This is set regarding the speed of vehicles that might use steering wheel 5 to perform emergency avoidance maneuvers. Second vehicle speed threshold V th2 The vehicle speed is set to what is considered a low-speed range. The second vehicle speed threshold V th2 It can be related to the first vehicle speed threshold V th1 Same value.

[0097] The second determining unit 72 is based on the vehicle speed V and the second vehicle speed threshold V. th2 The comparison result determines whether an emergency avoidance maneuver is possible. The second determining unit 72 bases the vehicle speed V on the comparison between the vehicle speed V and a second vehicle speed threshold V. th2 The comparison result sets the value of the second flag F2. When the vehicle speed V is less than the second vehicle speed threshold V... th2 When the second determining unit 72 determines that an emergency avoidance maneuver is unlikely, it sets the value of the second flag F2 to "0". When the vehicle speed V is greater than the second vehicle speed threshold V... th2 At that time, the second determining unit 72 determines that an emergency avoidance operation may be performed and sets the value of the second flag F2 to "1".

[0098] The second switch 73 receives a third setting value G3 set by the first switch 71B and a fourth setting value G4 stored in the memory as data input. The fourth setting value G4 is a fixed value, and for example, "1".

[0099] The second switch 73 receives the value of the second flag F2 set by the second determining unit 72 as a control input. The second switch 73 sets the value of the fifth setting value G5 based on the value of the second flag F2. When the value of the second flag F2 is "0", the second switch 73 selects the fourth setting value G4 ("1" in this document) as the fifth setting value G5. When the value of the second flag F2 is "1", the second switch 73 sets the third setting value G3 as the fifth setting value G5.

[0100] The gradient processor 74 receives a fifth setting value G5 selected by the second switch 73. The gradient processor 74 calculates a sixth setting value G6 by performing a time-dependent gradient process on the fifth setting value G5. The gradient process is a process of gradually changing the fifth setting value G5. The gradient processor 74 is configured, for example, to perform a so-called time-varying protection process that limits the change in the fifth setting value G5 per unit time to a predetermined limit value. The sixth setting value G6 is ultimately set to the fifth setting value G5. Furthermore, a low-pass filter can be used as the gradient processor 74.

[0101] Multiplier 75 receives the basic limit value T stored in memory. pth And the sixth setting value G6 calculated by the gradient processor 74. Basic limit value T pthIt is the fifth torque command value T p5 The basic limit is set, for example, as the rated torque of the steering motor 31. Basic limit T pth The default value is stored in memory. Multiplier 75 uses the basic limit T. pth The upper limit T is calculated by multiplying by the sixth setting value G6 calculated by the gradient processor 74. pUL .

[0102] The sign inversion processor 76 receives the upper limit T calculated by the multiplier 75. pUL The sign inversion processor 76 inverts the upper limit T. pUL The sign is used to calculate the lower limit T. pLL .

[0103] The processor 77 is limited to receiving the upper limit T calculated by the multiplier 75. pUL and the lower bound T calculated by the sign inversion processor 76 pLL The processor 77 is limited to using the received upper limit T. pUL and the received lower limit T pLL To execute the fifth torque command value T p5 Restricted processing.

[0104] The processor 77 will limit the fifth torque command value T p5 and upper limit T pUL Comparison. When the fifth torque command value T... p5 Greater than the upper limit T pUL At that time, the limiting processor 77 will set the fifth torque command value T. p5 Limit to upper limit T pUL Limited to an upper limit T. pUL The fifth torque command value T p5 Become the sixth torque command value T p6 .

[0105] The processor 77 will limit the fifth torque command value T p5 and lower limit T pLL Comparison. When the fifth torque command value T p5 Less than the lower limit T pLL At that time, the limiting processor 77 will set the fifth torque command value T. p5 Limit to lower limit T pLL It is restricted to a lower bound T. pLL The fifth torque command value T p5 Become the sixth torque command value T p6 .

[0106] When the fifth torque command value T p5 At the upper limit T pUL With lower limit T pLLWhen the value is within the range specified, processor 77 does not limit the fifth torque command value T. p5 The fifth torque command value T calculated by the first adder 63I. p5 Used as the sixth torque command value T without any changes. p6 .

[0107] Limit setting mode

[0108] Upper limit T pUL and lower limit T pLL The setting mode is as follows. When the value of the second flag F2 is "0", the fourth setting value G4 is set to the fifth setting value G5. For example, the fourth setting value G4 is "1". Therefore, the fifth setting value G5 is set to "1". The fifth setting value G5 is set to the sixth setting value G6 via the gradient processor 74. Since the fifth setting value G5 is "1", the sixth setting value G6 is ultimately "1". The basic limit value T stored in memory pth Used as the upper limit T without any changes pUL By adjusting the upper limit T pUL The sign is reversed to set the lower limit T. pLL The third setting value G3 is not used to calculate the upper limit T. pUL .

[0109] When the value of the second flag F2 is "1", the third setting value G3 is set to the fifth setting value G5. When the value of the first flag F1 is "0", the first setting value G1 is set to the third setting value G3. For example, the first setting value G1 is "1". Therefore, the fifth setting value G5 is set to "1". The fifth setting value G5 is set to the sixth setting value G6 via the gradient processor 74. Since the fifth setting value G5 is "1", the sixth setting value G6 is ultimately "1". That is, the basic limit value T stored in the memory... pth Used as the upper limit T without any changes pUL By adjusting the upper limit T pUL The sign is reversed to set the lower limit T. pLL .

[0110] When the value of the second flag F2 is "1", the third setting value G3 is set to the fifth setting value G5. When the value of the first flag F1 is "1", the second setting value G2 is set to the third setting value G3. The second setting value G2 is greater than the first setting value G1. Therefore, the third setting value G3 is set to a value greater than the first setting value G1. Since the first setting value G1 is "1", the third setting value G3 is greater than "1". That is, the third setting value G3, which has a value greater than "1", is set to the fifth setting value G5. The fifth setting value G5 is set to the sixth setting value G6 via the gradient processor 74.

[0111] Since the fifth setting value G5 has a value greater than "1", the sixth setting value G6 will ultimately be a value greater than "1". Therefore, by using the basic limit value T... pth The upper limit T obtained by multiplying by the sixth setting value G6 pUL Having a value greater than the basic limit T pth The value of . By adjusting the upper limit T pUL The sign is reversed to set the lower limit T. pLL Lower limit value T pLL The absolute value is greater than the basic limit T pth The absolute value of . Therefore, with respect to the fundamental limit T pth Used as upper limit T pUL Compared to the previous situation, the fifth torque command value T p5 The range of changes has expanded.

[0112] The second protection processor 63K and the third protection processor 63L have essentially the same configuration as the first protection processor 63J. For example... Figure 4 As indicated by the reference numerals within square brackets, the second protection processor 63K uses a seventh setting value G7 instead of the second setting value G2. The seventh setting value G7 is a value specific to the second protection processor 63K. The seventh setting value G7 is a fixed value and is set to, for example, a value greater than "1". Basic limit T pth It is also used as the third torque command value T p3 The basic limits.

[0113] Therefore, when the value of the second flag F2 is "0", and when the value of the second flag F2 is "1" and the value of the first flag F1 is "0", the basic limit T pth Used as upper limit T pUL By adjusting the upper limit T pUL The sign is reversed to set the lower limit T. pLL When the value of the second flag F2 is "1" and the value of the first flag F1 is "1", it is consistent with the basic limit T. pth Used as upper limit T pUL Compared to the previous situation, the third torque command value T p3 The range of changes has expanded.

[0114] like Figure 4 As indicated by the reference numerals within square brackets, the third protection processor 63L uses the eighth setting value G8 instead of the second setting value G2. The eighth setting value G8 is a value specific to the third protection processor 63L. The eighth setting value G8 is a fixed value and is set to, for example, a value greater than "1". Basic limit T pth It is also used as the fourth torque command value T p4 The basic limits.

[0115] Therefore, when the value of the second flag F2 is "0", and when the value of the second flag F2 is "1" and the value of the first flag F1 is "0", the basic limit T pth Used as upper limit T pUL By adjusting the upper limit T pUL The sign is reversed to set the lower limit T. pLL When the value of the second flag F2 is "1" and the value of the first flag F1 is "1", it is consistent with the basic limit T. pth Used as upper limit T pUL Compared to the previous situation, the fourth torque command value T p4 The range of changes has expanded.

[0116] Operation in the first embodiment

[0117] The operation of the first embodiment will now be described. It is conceivable that the first protection processor 63J, the second protection processor 63K, and the third protection processor 63L use the basic limit T. pth Basic limit T pth This is a fixed value independent of the vehicle speed V. In this case, for example, when performing an emergency maneuver using steering wheel 5, the following concerns arise. Note in this article the fourth torque command value T. p4 and the fifth torque command value T p5 .

[0118] like Figure 5 The graph shows the fourth torque command value T calculated by the damping controller 63H. p4 The absolute value of the fifth torque command value T calculated by the first adder 63I and the fifth torque command value T p5 The absolute value increases over time and reaches the basic limit T. pth For example, the fifth torque command value T p5 The slope of the absolute value is greater than the fourth torque command value T. p4 The slope of the absolute value of the torque command value. The slope is the rate of change of the absolute value of the torque command value over time. Therefore, the fourth torque command value T p4 The absolute value reaches the basic limit T pth The time (time T1) is later than the fifth torque command value T. p5 The absolute value reaches the basic limit T pth The time.

[0119] At the fourth torque command value T p4 The absolute value reaches the basic limit T pth Then, the fifth torque command value T p5 The absolute value and the fourth torque command value T p4 The absolute values ​​of both are restricted to the basic limit T. pth In other words, the fourth torque command value Tp4 The absolute value and the fifth torque command value T p5 The absolute value becomes the same. Fourth torque command value T p4 This is the value subtracted by the third subtractor 63N. Therefore, in the fourth torque command value T... p4 The absolute value reaches the basic limit T pth Then, the fourth torque command value T p4 and the fifth torque command value T p5 They may cancel each other out. Therefore, there is a concern that steering wheel 6 may not be able to steer properly in response to an emergency avoidance maneuver using steering wheel 5.

[0120] On the other hand, according to this embodiment, when an emergency avoidance maneuver using the steering wheel 5 may be performed, the third torque command value T p3 Up to the fifth torque command value T p5 The range of variation has expanded. For example, a situation where an emergency avoidance maneuver might be required is when the vehicle is traveling at a speed exceeding the first vehicle speed threshold V. th1 Second vehicle speed threshold V th2 The speed at which it travels.

[0121] In this embodiment, consideration is given to expanding the third torque command value T. p3 Up to the fifth torque command value T p5 There are two modes for varying the range of changes. Depending on the product specifications, one of the two modes will be used.

[0122] The first mode is a mode in which the second setting value G2 used by the first protection processor 63J, the seventh setting value G7 used by the second protection processor 63K, and the eighth setting value G8 used by the third protection processor 63L are all set to the same value. In this mode, all settings of the second setting value G2, the seventh setting value G7, and the eighth setting value G8 are set to values ​​greater than "1".

[0123] The second mode is a mode in which the second setting value G2 used by the first protection processor 63J, the seventh setting value G7 used by the second protection processor 63K, and the eighth setting value G8 used by the third protection processor 63L are set to different values. In this mode, all setting values ​​of the second setting value G2, the seventh setting value G7, and the eighth setting value G8 are set to values ​​greater than "1". At least the second setting value G2 is set to a value greater than the eighth setting value G8. This is to ensure that the steering torque command value T... p * The value of the first torque command T, calculated by the proportional controller 63E, is reflected more in the value of the first torque command. p1 .

[0124] First Mode

[0125] The operation in the first mode will be described below. Note the fourth torque command value T in this document. p4 With the fifth torque command value T p5 The relationship between them. This is because of the fifth torque command value T. p5 This is achieved by adjusting the first torque command value T calculated by the proportional controller 63E. p1 The second torque command value T calculated by the integral controller 63F p2 The summation of these values ​​has a significant impact on the steering performance of steering wheel 6. For example, both the second setting value G2 and the eighth setting value G8 are set to "3".

[0126] like Figure 6 As shown in the curve, the fourth torque command value T p4 The absolute value limit and the fifth torque command value T p5 The absolute value limits for both are fundamental limits T. pth Three times the value.

[0127] Fifth torque command value T p5 The absolute value increases over time. Fifth torque command value T p5 The absolute value exceeds the basic limit T pth And eventually reach the basic limit T. pth Three times the limit. At the fifth torque command value T p5 After the absolute value reaches the limit, the fifth torque command value T p5 The absolute value remains in a state where it is restricted to the limit.

[0128] Fourth torque command value T p4 The absolute value increases over time. The fourth torque command value T p4 The absolute value exceeds the basic limit T pth And in the fourth torque command value T p4 The absolute value reaches the basic limit T pth Saturation occurs before reaching three times the limit. At the fourth torque command value T... p4 After the absolute value has saturated, the fourth torque command value T p4 The absolute value remains at the basic limit T. pth With basic limit T pth The saturation value between three times the limit.

[0129] In this way, the fourth torque command value T p4 The absolute value limit and the fifth torque command value T p5 The absolute value limits for both are increased to be greater than the basic limit T. pth The same value. Therefore, it is possible to avoid setting the fourth torque command value T to the same value. p4The absolute value and the fifth torque command value T p5 The absolute value is limited to the same value. Therefore, due to the fourth torque command value T p4 The absolute value and the fifth torque command value T p5 There is a difference between the absolute values, thus suppressing the fourth torque command value T. p4 and the fifth torque command value T p5 The offsetting effect.

[0130] Second Mode

[0131] The operation in the second mode will be described below. Also note the fourth torque command value T in this document. p4 With the fifth torque command value T p5 The relationship between them. For example, the second setting value G2 is set to "5", and the eighth setting value G8 is set to "2".

[0132] like Figure 7 As shown in the curve, the fourth torque command value T p4 The limit of the absolute value is the basic limit T. pth Double the value. Fifth torque command value T p5 The limit of the absolute value is the basic limit T. pth Five times the value.

[0133] Fifth torque command value T p5 The absolute value increases over time. The absolute value of the fifth torque command value Tp5 exceeds the basic limit T. pth And in the fifth torque command value T p5 The absolute value reaches the basic limit T pth Saturation occurs before reaching five times the limit. At the fifth torque command value T... p5 After the absolute value has saturated, the fifth torque command value T p5 The absolute value remains at the basic limit T. pth With basic limit T pth The saturation value between five times the limit.

[0134] Fourth torque command value T p4 The absolute value increases over time. The fourth torque command value T p4 The absolute value exceeds the basic limit T pth And in the fourth torque command value T p4 The absolute value reaches the basic limit T pth Saturation occurs before reaching twice the limit. At the fourth torque command value T. p4 After the absolute value has saturated, the fourth torque command value T p4 The absolute value remains at the basic limit T. pth With basic limit T pthThe saturation value between twice the limit.

[0135] In this way, the fourth torque command value T p4 The absolute value limit and the fifth torque command value T p5 The absolute value limits of both are increased to be greater than the basic limit T. pth Different values ​​of T. Therefore, it is possible to avoid setting the fourth torque command value T. p4 The absolute value and the fifth torque command value T p5 The absolute value is limited to the same value. Therefore, due to the fourth torque command value T p4 The absolute value and the fifth torque command value T p5 There is a difference between the absolute values, thus suppressing the fourth torque command value T. p4 and the fifth torque command value T p5 The offsetting effect.

[0136] Advantages of the first embodiment

[0137] According to the first embodiment, the following advantages can be achieved. Fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limit is increased individually based on the vehicle's driving conditions. For example, when an emergency avoidance maneuver might be performed using steering wheel 5, the fourth torque command value T... p4 The limit value and the fifth torque command value T p5 Both limits are increased to be greater than the basic limit T. pth The value of . That is, the fourth torque command value T. p4 Variation range and fifth torque command value T p5 The range of variation is expanded. Therefore, it is possible to avoid changing the fourth torque command value T. p4 and the fifth torque command value T p5 The limit is set to the same value. This is due to the fourth torque command value T. p4 With the fifth torque command value T p5 There is a difference between them, therefore the fourth torque command value T can be suppressed. p4 and the fifth torque command value T p5 The offset. Fifth torque command value T p5 This is achieved by adjusting the first torque command value T calculated by the proportional controller 63E. p1 The second torque command value T calculated by the integral controller 63F p2 The summation of these values ​​significantly affects the steering performance of steering wheel 6. Therefore, steering wheel 6 can be appropriately steered according to emergency avoidance maneuvers using steering wheel 5.

[0138] When multiplied by the basic limit T pthWhen the fifth setting value G5 switches between the third setting value G3 and the fourth setting value G4, the gradient processor 74 performs a gradient processing on the fifth setting value G5. Therefore, the third torque command value T can be suppressed. p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 Rapid changes in the limit value can therefore suppress the steering torque command value T. p * And rapid changes in steering force generated by steering motor 31.

[0139] When the vehicle speed V exceeds the first vehicle speed threshold V th1 And exceeds the second vehicle speed threshold V th2 At that time, the fourth torque command value T p4 The absolute value limit and the fifth torque command value T p5 The absolute value limits for both are increased to be greater than the basic limit T. pth The value. The vehicle is traveling at a speed higher than the first vehicle speed threshold V. th1 and above the second vehicle speed threshold V th2 The vehicle's speed at which it is traveling is one of the vehicle states in which emergency avoidance maneuvers may be performed. Therefore, the fourth torque command value T can be increased based on the vehicle state. p4 The absolute value limit range and the fifth torque command value T p5 The range of variation of the absolute value of.

[0140] When the second mode is used to expand the range of variation of the limit, and when the vehicle speed V exceeds the first vehicle speed threshold V... th1 And exceeds the second vehicle speed threshold V th2 At that time, the fifth torque command value T p5 The limit is set to be greater than the fourth torque command value T. p4 The limit value. Therefore, the steering torque command value T p * In addition to the fifth torque command value T calculated by the first adder 63I, p5 In addition, it can also reflect more of the first torque command value T calculated by the proportional controller 63E. p1 and the second torque command value T calculated by the integral controller 63F p2 .

[0141] Second Implementation Method

[0142] The steering control device according to the second embodiment will now be described. This embodiment basically employs the same... Figure 1 , Figure 2 and Figure 4The configuration is the same as that of the first embodiment shown. This embodiment differs from the first embodiment in the configuration of the pinion angle feedback controller 63. Therefore, the same elements as in the first embodiment will be indicated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0143] like Figure 8 As shown, the pinion angle feedback controller 63 includes a first subtractor 63A, a first differentiator 63B, a second differentiator 63C, and a second subtractor 63D. The pinion angle feedback controller 63 also includes a proportional controller 63E, an integral controller 63F, a differential controller 63G, and a damping controller 63H. The pinion angle feedback controller 63 further includes a second protection processor 63K and a third protection processor 63L.

[0144] In addition to these components, the pinion angle feedback controller 63 also includes a fifth protection processor 63P, a sixth protection processor 63Q, a calculator 63R, and a seventh protection processor 63S.

[0145] The fifth protection processor 63P and the sixth protection processor 63Q have the same characteristics as... Figure 4 The first adder 63I, the first protection processor 63J, the second protection processor 63K, and the third protection processor 63L shown have the same configuration.

[0146] The fifth protection processor 63P receives the first torque command value T calculated by the proportional controller 63E. p1 The vehicle speed V detected by vehicle speed sensor 41. The fifth protection processor 63P calculates the first torque command value T based on the vehicle speed V. p1 The limits. The limits include the first torque command value T. p1 The upper and lower limits. The fifth protection processor 63P adjusts the first torque command value T based on the upper and lower limits. p1 The fifth protection processor 63P performs constraint processing to calculate the eleventh torque command value T. p11 .

[0147] As by Figure 4 As indicated by the reference numerals within parentheses, the fifth protection processor 63P uses the ninth setting value G9 instead of the second setting value G2. The ninth setting value G9 is a value specific to the fifth protection processor 63P. The ninth setting value G9 is a fixed value and is set to, for example, a value greater than "1". Basic limit value T pth Also used as the first torque command value T p1 The basic limits.

[0148] The sixth protection processor 63Q receives the second torque command value T calculated by the integral controller 63F. p2The vehicle speed V detected by vehicle speed sensor 41. The sixth protection processor 63Q calculates the second torque command value T based on the vehicle speed V. p2 The limits. The limits include the second torque command value T. p2 The upper and lower limits. The sixth protection processor 63Q adjusts the second torque command value T based on the upper and lower limits. p2 The sixth protection processor 63Q performs constraint processing to calculate the twelfth torque command value T. p12 .

[0149] As by Figure 4 As indicated by the reference numerals within brackets, the sixth protection processor 63Q uses the tenth setting value G10 instead of the second setting value G2. The tenth setting value G10 is a value specific to the sixth protection processor 63Q. The tenth setting value G10 is a fixed value and is set to, for example, a value greater than "1". Basic limit value T pth Also used as the second torque command value T p2 The basic limits.

[0150] Calculator 63R receives the eleventh torque command value T calculated by the fifth protection processor 63P. p11 The twelfth torque command value T calculated by the sixth protection processor 63Q p12 The seventh torque command value T calculated by the second protection processor 63K p7 And the eighth torque command value T calculated by the third protection processor 63L. p8 Calculator 63R uses the eleventh torque command value T. p11 12th Torque Command Value T p12 and the seventh torque command value T p7 Summing and subtracting the eighth torque command value T from the summation value. p8 To calculate the thirteenth torque command value T p13 .

[0151] The seventh protection processor 63S receives the thirteenth torque command value T calculated by the calculator 63R. p13 The seventh protection processor 63S includes the thirteenth torque command value T. p13 The limits. The limits include the thirteenth torque command value T. p13 The upper and lower limits. The seventh protection processor 63S bases the thirteenth torque command value T on the upper and lower limits. p13 The seventh protection processor 63S performs constraint processing to calculate the final steering torque command value T for controlling the steering motor 31. p * .

[0152] The fifth protection processor 63P and the sixth protection processor 63Q constitute the third processor. The calculator 63R constitutes the fourth processor. According to the second embodiment, in addition to the advantages of the first embodiment, the following advantages can also be achieved.

[0153] First torque command value T p1 To the fourth torque command value T p4 The absolute value limit is increased individually based on the vehicle's driving conditions. For example, when an emergency avoidance maneuver may be performed using steering wheel 5, the first torque command value T... p1 To the fourth torque command value T p4 The absolute value limit is increased to be greater than the basic limit T. pth Different values. That is, the first torque command value T. p1 To the fourth torque command value T p4 The range of variation is expanded. Therefore, it is possible to avoid setting the first torque command value T... p1 To the third torque command value T p3 The absolute value and the fourth torque command value T p4 The absolute values ​​are limited to the same value. Therefore, due to the first torque command value T p1 To the third torque command value T p3 The absolute value and the fourth torque command value T p4 There is a difference between the absolute values, thus suppressing the first torque command value T. p1 To the third torque command value T p3 The absolute value and the fourth torque command value T p4 The absolute values ​​are canceled out. Specifically, this is because the first torque command value T is avoided. p1 With the fourth torque command value T p4 The offset can be achieved by turning the steering wheel 6 appropriately according to the emergency avoidance operation using the steering wheel 5.

[0154] Third Implementation Method

[0155] The steering control device according to the third embodiment will now be described. This embodiment basically employs the same... Figure 1 , Figure 2 and Figure 4 The configuration is the same as that of the first embodiment shown. This embodiment differs from the first embodiment in the configuration of the setting unit 71 of the pinion angle feedback controller 63. Therefore, the same elements as in the first embodiment will be indicated by the same reference numerals, and detailed descriptions thereof will be omitted. This embodiment can be applied to... Figure 8 The second embodiment shown.

[0156] Figure 4The setting unit 71 shown uses a mapping to calculate the third setting value G3. The mapping is stored in memory. When using the command value T for amplifying the third torque... p3 Up to the fifth torque command value T p5 When the range of changes is in the first mode, the setting unit 71 of the first protection processor 63J, the second protection processor 63K, and the third protection processor 63L uses the first mapping.

[0157] like Figure 9 As shown, the first mapping M1 is a mapping where the horizontal axis is set to the vehicle speed V and the vertical axis is set to a third setting value G3, defining the relationship between the vehicle speed V and the third setting value G3. The first mapping M1 has the following characteristics: That is, from the value of vehicle speed V "0" to the first vehicle speed threshold V... th1 Within the specified range, a quiet zone is defined by setting the third setting value G3 to "1". When the vehicle speed V is greater than the first vehicle speed threshold V... th1 At that time, the third setting value G3 increases linearly with the increase of the vehicle speed V.

[0158] Therefore, when the vehicle speed V has exceeded the first vehicle speed threshold V th1 Then, the third torque command value T p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limits have all been increased to be greater than the basic limit T. pth The same value. As the vehicle speed V increases, the third torque command value T... p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limit has been increased.

[0159] When this implementation method is applied to the second implementation method, the setting units 71 of the fifth protection processor 63P and the sixth protection processor 63Q are also used. Figure 9 The first mapping M1 is shown.

[0160] When using the command value T for amplifying the third torque p3 Up to the fifth torque command value T p5 In the second mode of varying range, the setting unit 71 of the first protection processor 63J, the second protection processor 63K, and the third protection processor 63L uses a second mapping. The second mapping used for the setting unit 71 has different characteristics.

[0161] like Figure 10As shown, the second mapping M2 is a mapping in which the horizontal axis is set to the vehicle speed V and the vertical axis is set to a third setting value G3, defining the relationship between the vehicle speed V and the third setting value G3. The second mapping M2 used by the setting unit 71 of the first protection processor 63J has the following characteristics. That is, as shown by feature line L1, the quiet zone where the third setting value G3 is "1" is set from the value of the vehicle speed V ("0") to the first vehicle speed threshold V. th1 Within the range. When the value of vehicle speed V is greater than the first vehicle speed threshold V... th1 At that time, the third setting value G3 increases linearly with the increase of the vehicle speed V.

[0162] The second mapping M2 used by the setting unit 71 of the second protection processor 63K has the following characteristics. That is, as shown by feature line L2, the quiet zone where the third setting value G3 is "1" is set from the value of vehicle speed V "0" to the first vehicle speed threshold V. th1 Within the range. When the value of vehicle speed V is greater than the first vehicle speed threshold V... th1 When the vehicle speed V increases, the third setting value G3 increases linearly. When the vehicle speed V exceeds the first vehicle speed threshold V... th1 The slope of the subsequent feature line L2 is less than the value of the vehicle speed V when it exceeds the first vehicle speed threshold V. th1 The slope of the subsequent characteristic line L1. The slope is the rate of change of the third setting value G3 relative to the vehicle speed V.

[0163] The second mapping M2 used by the setting unit 71 of the third protection processor 63L has the following characteristics. That is, as shown by feature line L3, the quiet zone where the third setting value G3 is "1" is set from the value of vehicle speed V "0" to the first vehicle speed threshold V. th1 Within the range. When the value of vehicle speed V is greater than the first vehicle speed threshold V... th1 When the vehicle speed V increases, the third setting value G3 increases linearly. When the vehicle speed V exceeds the first vehicle speed threshold V... th1 The slope of the subsequent feature line L3 is less than the value of the vehicle speed V when it exceeds the first vehicle speed threshold V. th1 The slope of the subsequent characteristic line L2.

[0164] Therefore, when the vehicle speed V has exceeded the first vehicle speed threshold V th1 Then, the third torque command value T p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limits have all been increased to be greater than the basic limit T. pthDifferent values. As the vehicle speed V increases, the third torque command value T... p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limit has been increased.

[0165] When this implementation is applied to the second implementation, the second mapping M2 used by the setting unit 71 of the fifth protection processor 63P and the sixth protection processor 63Q has, for example, Figure 10 The feature indicated by feature line L1 in the diagram.

[0166] Advantages of the third implementation method

[0167] According to the third embodiment, in addition to the advantages of the first and second embodiments, the following advantages can also be achieved.

[0168] When the vehicle speed V is greater than the first vehicle speed threshold V th1 At that time, the third torque command value T p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limit increases with the vehicle speed V. Therefore, the third torque command value T can be appropriately increased based on the vehicle speed V. p3 Limit value, fourth torque command value T p4 The limit value and the fifth torque command value T p5 The limit. As the vehicle speed V increases, the steering wheels 6 need to be turned appropriately according to the emergency avoidance operation using the steering wheel 5.

[0169] Other implementation methods

[0170] The aforementioned implementation can be modified as follows. In the second implementation, the second torque command value T calculated by the integral controller 63F is... p2 The sixth protection processor 63Q can be configured not to change the second torque command value T based on vehicle speed V. p2 The limit. In this case, the sixth protection processor 63Q, for example, uses the basic limit T. pth To limit the second torque command value T p2 Regardless of the vehicle speed V.

[0171] In the first to third embodiments, the pinion angle feedback controller 63 can be configured such that the fourth protection processor 63O is omitted. In this case, the tenth setting value G10 calculated by the third subtractor 63N serves as the final steering torque command value T for controlling the steering motor 31. p * .

[0172] In the first to third embodiments, the pinion angle feedback controller 63 can be configured such that the differential controller 63G and the second protection processor 63K are omitted. In this case, the first differentiator 63B, the second subtractor 63D, and the second adder 63M can be omitted. The third subtractor 63N receives the sixth torque command value T calculated by the first protection processor 63J. p6 .

[0173] In the first to third embodiments, the protection processors (63J, 63K, 63L, 63P, and 63Q) may be configured such that the gradient processor 74 is omitted. In this case, the multiplier 75 receives the fifth setting value G5 set by the second switch 73.

[0174] In the first to third embodiments, the first vehicle speed threshold V can be appropriately changed. th1 Second vehicle speed threshold V th2 The first vehicle speed threshold V th1 Second vehicle speed threshold V th2 This can be either a speed within the medium speed range or a speed within the high speed range. The medium speed range, for example, is a speed range equal to or higher than 40 km / h and lower than 60 km / h. The high speed range, for example, is a speed range equal to or higher than 60 km / h. In other words, the first vehicle speed threshold V can be... th1 Second vehicle speed threshold V th2 Set the speed to, for example, a range from 20 km / h to 100 km / h.

[0175] In the first to third embodiments, the vehicle speed V can be a speed calculated based on the vehicle wheel speed detected by the vehicle wheel speed sensor. The vehicle speed V can also be a speed based on a signal other than the vehicle wheel speed. For example, the vehicle speed V can be the vehicle body speed detected by the vehicle body speed sensor. The vehicle body speed is the speed of the vehicle body relative to the road surface. When using the vehicle body speed, the influence of wheel slippage can be eliminated. Figure 4 The first determining unit 71A can receive speed based on the vehicle wheel speed, and the second determining unit 72 can receive the vehicle body speed.

[0176] In the first to third embodiments, the torque command value (T) can be changed based on other vehicle state parameters B1 to B4 instead of vehicle speed V or other vehicle state parameters B1 to B4 besides vehicle speed V. p3 T p4 And T p5 or T p1 T p2 T p3 And Tp4 The vehicle's driving state is reflected in vehicle state parameters B1 to B4. The vehicle's driving state includes, for example, vehicle behavior after an emergency avoidance maneuver. In the event of an emergency avoidance maneuver, the values ​​of vehicle state parameters B1 to B4 increase. This is because the amount of steering wheel 5 operation and the steering speed increase rapidly during an emergency avoidance maneuver. For example, when the values ​​of vehicle state parameters B1 to B4 exceed a predetermined threshold, the first determining unit 71A and the second determining unit 72 determine that an emergency avoidance maneuver may be performed.

[0177] Examples of vehicle state parameters include B1. Yaw rate, B2. Lateral acceleration, and B3. Target pinion angle θ. p * Angle θ of the actual pinion p The ratio between (θ) p * / θ p B4. Target pinion angular velocity ω p * With respect to the actual angular velocity ω of the pinion p The ratio between (ω) p * / ω p For example, yaw rate is detected by a yaw rate sensor installed in the vehicle. Lateral acceleration is detected by a lateral acceleration sensor installed in the vehicle.

Claims

1. A steering control device for controlling a steering motor (31) that generates a steering force for a steering wheel (6) of a vehicle, the steering control device calculating a target angle of a rotating member (21) that rotates with the operation of the steering wheel (6) based on the steering operation state of a steering wheel (5), and calculating a steering torque command value of the steering motor (31) by performing feedback control such that the actual angle of the rotating member (21) conforms to the target angle, the steering control device being characterized by comprising: A first processor (63E, 63F, 63G) is configured to calculate a torque command value based on the difference between the target angle and the actual angle; A second processor (63H) is configured to calculate a compensation value for the torque command value based on the target angular velocity or actual angular velocity of the rotating member (21), the compensation value acting in the opposite direction to the torque command value. A third processor (63J, 63K, 63L) is configured to perform limiting processing to limit the range of variation of the torque command value based on a limit of the torque command value, and to limit the range of variation of the compensation value based on a limit of the compensation value. as well as A fourth processor (63N) is configured to calculate the steering torque command value using the torque command value after the execution of the limiting process and the compensation value after the execution of the limiting process. The third processor (63J, 63K, 63L) is configured to increase the limit of the torque command value and the limit of the compensation value based on the driving state of the vehicle.

2. The steering control device according to claim 1, characterized in that, The third processor (63J, 63K, 63L) is configured to increase the limit of the torque command value and the limit of the compensation value when the value of the vehicle status parameter is greater than a predetermined threshold. The vehicle status parameter is a parameter reflecting the driving state of the vehicle.

3. The steering control device according to claim 2, characterized in that, The third processor (63J, 63K, 63L) is configured to increase the limit of the torque command value and the limit of the compensation value to the same value when the value of the vehicle state parameter is greater than the threshold.

4. The steering control device according to claim 2, characterized in that, The third processor (63J, 63K, 63L) is configured to increase the limit of the torque command value and the limit of the compensation value to different values ​​when the value of the vehicle state parameter is greater than the threshold.

5. The steering control device according to claim 4, characterized in that, The limit of the torque command value is greater than the limit of the compensation value.

6. The steering control device according to any one of claims 2 to 5, characterized in that, The third processor (63J, 63K, 63L) is configured to increase the limit of the torque command value and the limit of the compensation value as the value of the vehicle state parameter increases when the value of the vehicle state parameter is greater than the threshold.

7. The steering control device according to any one of claims 2 to 5, characterized in that, The values ​​of the vehicle state parameters are the vehicle speed detected by the on-board sensors, the yaw rate, the ratio of the actual angle to the target angle, or the ratio of the actual angular velocity to the target angular velocity.

8. The steering control device according to any one of claims 2 to 5, characterized in that, The third processor (63J, 63K, 63L) is configured to determine that an emergency avoidance operation using the steering wheel (5) may be performed when the value of the vehicle state parameter is greater than the threshold.

9. The steering control device according to any one of claims 1 to 5, characterized in that, The third processor (63J, 63K, 63L) includes a gradient processor (74) configured to gradually change the limits of the torque command value and the compensation value over time by performing gradient processing on the limits of the torque command value and the compensation value.

10. The steering control device according to any one of claims 1 to 5, characterized in that, The torque command value includes a first torque command value having a value proportional to the difference and a second torque command value having a value proportional to the integral of the difference. The first torque command value is calculated by performing a proportional operation on the difference, and the second torque command value is calculated by performing an integral operation on the difference. The third processor (63J, 63K, 63L) is configured to limit the range of variation of the sum of the first torque command value and the second torque command value based on a limit.

11. The steering control device according to any one of claims 1 to 5, characterized in that, The torque command value includes a first torque command value having a value proportional to the difference and a second torque command value having a value proportional to the integral of the difference. The first torque command value is calculated by performing a proportional operation on the difference, and the second torque command value is calculated by performing an integral operation on the difference. The third processor (63J, 63K, 63L) is configured to limit the range of variation of the first torque command value based on a limit of the first torque command value, and to limit the range of variation of the second torque command value based on a limit of the second torque command value.

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