Steering control device

Abstract

A steering control device (1) controls a steering device (2) that has a motor (31, 12) that generates torque that is applied to an operation element (5) of a vehicle. The steering control device controls the motor on the basis of a torque command value that is computed in accordance with the operation state of the operation element. The steering control device has a disturbance estimator (65) that uses a model that simulates the steering device to compute a disturbance torque that is a torque that affects a steered wheel (6) of the vehicle but is not the torque generated by the motor (31), a first processing unit (62B, 62D, 82) that generates an adjustment amount (F2, F5) for adjusting the torque command value on the basis of the disturbance torque computed by the disturbance estimator, and a second processing unit (62E, 62F, 71, 83) that causes the adjustment amount calculated by the first processing unit to be reflected in a state variable that is the basis for computation of the torque command value.

Description

Steering control device

[0001] The present disclosure relates to a steering control device.

[0002] Conventionally, there has been known a so-called steer-by-wire steering device in which the steering wheel and the steered wheels are mechanically separated so that mechanical power transmission between them is not possible. This steering device has a reaction motor, a turning motor, and a control device. The reaction motor generates a steering reaction force that is applied to the steering shaft. The turning motor generates a steering force that steers the steered wheels. When the vehicle is traveling, the control device controls the reaction motor to generate the steering reaction force, and controls the turning motor to turn the steered wheels.

[0003] For example, the control device in Patent Document 1 calculates an angle axial force and a current axial force. The angle axial force and the current axial force are axial forces acting on a steering shaft that steers the steered wheels. The angle axial force is an axial force that corresponds to a target rotation angle of a pinion shaft that rotates in conjunction with the steered wheels, and is an axial force that does not reflect road surface conditions. The current axial force is an axial force that corresponds to the current value of a steering motor, and is an axial force that reflects road surface conditions.

[0004] The control device calculates the final axial force by multiplying the angular axial force and the current axial force by a distribution ratio that is individually set according to factors such as vehicle speed, and then adding the results. The control device uses the final axial force to control the reaction motor. Because the road surface condition is reflected in the road axial force, the road surface condition is also reflected in the steering reaction force generated by the reaction motor. Therefore, the driver can recognize the road surface condition by the feel via the steering wheel.

[0005] Japanese Patent Application Laid-Open No. 2022-155295

[0006] A steering control device is required to give a vehicle driver a more appropriate steering feel via an operator such as a steering wheel.

[0007] A steering control device according to one aspect of the present disclosure is configured to control a steering device having a motor that generates torque to be applied to an operator of a vehicle, and to control the motor based on a torque command value calculated in accordance with an operation state of the operator. The steering control device includes: a disturbance estimator configured to calculate, using a model simulating the steering device, a disturbance torque that affects steered wheels of the vehicle and is torque other than the torque generated by the motor, a first processing unit configured to generate an adjustment amount for adjusting the torque command value based on the disturbance torque calculated by the disturbance estimator, and a second processing unit configured to reflect the adjustment amount generated by the first processing unit in a state variable that is a basis for calculating the torque command value.

[0008] FIG. 1 is a configuration diagram of a steering device equipped with a steering control device according to a first embodiment. FIG. 2 is a block diagram of the steering control device in FIG. 1. FIG. 3 is a block diagram of an axial force torque calculation unit in FIG. 2. FIG. 4 is a block diagram showing main parts of a steering control device according to a second embodiment. FIG. 5 is a block diagram showing main parts of a steering control device according to a third embodiment. FIG. 6 is a block diagram showing main parts of a steering control device according to a fourth embodiment. FIG. 7 is a block diagram showing main parts of a steering control device according to a fifth embodiment. FIG. 8 is a block diagram showing main parts of a steering control device according to a sixth embodiment. FIG. 9 is a block diagram showing main parts of a steering control device according to a seventh embodiment. FIG. 10 is a block diagram showing main parts of a steering control device according to an eighth embodiment. FIG. 11 is a configuration diagram of a steering device equipped with a steering control device according to a ninth embodiment. FIG. 12 is a block diagram showing main parts of a steering control device according to a ninth embodiment. FIG. 13 is a block diagram showing main parts of a steering control device according to a tenth embodiment. FIG. 14 is a block diagram showing main parts of a steering control device according to an eleventh embodiment. FIG. 15 is a block diagram showing main parts of a steering control device according to a twelfth embodiment.

[0009] <First embodiment> A steering control device according to the first embodiment will be described. <Configuration of steering device 2> As shown in Fig. 1 , the control target of the steering control device 1 is a vehicle steering device 2. The steering device 2 is, for example, an electric power steering device, and has a steering mechanism 3 and a turning mechanism 4. The steering mechanism 3 is a mechanical part that is steered by the driver via a steering wheel 5. The turning mechanism 4 is a mechanical part that steers steered wheels 6 of the vehicle in response to steering of the steering wheel 5. The steering wheel 5 is an operator that is operated by the driver when changing the traveling direction of the vehicle.

[0010] The steering mechanism 3 has a steering shaft 11. The steering wheel 5 is connected to a first end of the steering shaft 11 so as to be rotatable together with the steering mechanism 4. The steering mechanism 4 has a pinion shaft 21, a steered shaft 22, and a housing 23. The housing 23 rotatably supports the pinion shaft 21. The pinion shaft 21 is arranged to intersect with the steered shaft 22. The first end of the pinion shaft 21 is connected to a second end of the steering shaft 11 so as to be rotatable together with the steering mechanism 4. The second end of the pinion shaft 21 is provided with pinion teeth 21a.

[0011] The housing 23 also accommodates the steered shaft 22 so that it can reciprocate. The steered shaft 22 has rack teeth 22a. The rack teeth 22a mesh with the pinion teeth 21a. Tie rods 25 are connected to both ends of the steered shaft 22 via rack ends 24 made up of ball joints. The ends of the tie rods 25 are connected to knuckles (not shown) to which the steered wheels 6 are attached. In other words, the steering wheel 5 and the steered wheels 6 are connected so that power can be transmitted between them.

[0012] The steering mechanism 4 includes a steering motor 31, a transmission mechanism 32, and a conversion mechanism 33. The steering motor 31 functions as an assist motor that generates an assist force to be applied to the steering shaft 22. The assist force is a force that assists in steering the steering wheel 5. The steering motor 31 is, for example, a three-phase brushless motor. The transmission mechanism 32 is, for example, a belt transmission mechanism. The 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 via the transmission mechanism 32 into axial movement of the steering shaft 22.

[0013] The steered shaft 22 moves in the axial direction, and the steered angle θ of the steered wheels 6 ｗ The pinion teeth 21 a of the pinion shaft 21 mesh with the rack teeth 22 a of the steered shaft 22. Therefore, the pinion shaft 21 rotates in conjunction with the movement of the steered shaft 22. The pinion shaft 21 is a rotating body that rotates in conjunction with the steering operation of the steered wheels 6.

[0014] The steering control device 1 executes assist control. The assist control is performed by the steering motor 31 applying a steering torque T ｈ This is a control for supplying power to the steering motor 31 so as to generate an assist torque according to the steering control device 1. The steering control device 1 has a processing circuit including any one of the following three configurations A1, A2, and A3.

[0015] A1. One or more processors that operate according to a computer program, which is software. The processor includes a CPU (Central Processing Unit) and memory. A2. One or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), that execute at least some of the various processes. The ASIC includes a CPU and memory.

[0016] A3. A hardware circuit that combines configurations A1 and A2. The memory is a computer-readable medium that stores a program that describes processes or instructions for the computer. In this embodiment, the computer is a CPU. The memory includes RAM (Random Access Memory) and ROM (Read Only Memory). The CPU performs various controls by executing the program stored in the memory at a predetermined calculation cycle.

[0017] The steering control device 1 receives detection results from sensors mounted on the vehicle. The 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. The vehicle speed V is a state variable that reflects the running state of the vehicle. The torque sensor 42 is provided on the steering shaft 11. The torque sensor 42 detects the steering torque T applied to the steering shaft 11. ｈ Detects the steering torque T ｈ is calculated based on the amount of twist of the torsion bar 42a provided on the steering shaft 11. ｈ is a state variable that reflects the steering state of the steering wheel 5. The rotation angle sensor 43 is provided in the steering motor 31. The rotation angle sensor 43 detects the rotation angle θ of the steering motor 31. ｂ Detect.

[0018] Steering torque T ｈ , and the rotation angle θ of the steering motor 31 ｂ is a positive value when the steering wheel 5 is steered to the right, and is a negative value when the steering wheel 5 is steered to the left, for example.

[0019] The steering control device 1 uses the detection results of the vehicle speed sensor 41, the torque sensor 42, and the rotation angle sensor 43 to control the operation of the steering motor 31. The steering control device 1 controls the steering torque T ｈ The power supply to the steering motor 31 is controlled so that the steering motor 31 generates an assist torque corresponding to the torque.

[0020] <Configuration of Steering Control Device 1> Next, the configuration of the steering control device 1 will be described. As shown in Fig. 2, the steering control device 1 has a target steering torque calculation unit 51, a torque feedforward control unit 52, a torque feedback control unit 53, a first disturbance estimator 54, a first calculator 55, and a second calculator 56. The steering control device 1 also has a target angle calculation unit 61, an axial force torque calculation unit 62, an angle feedforward control unit 63, an angle feedback control unit 64, a second disturbance estimator 65, and a third calculator 66. The steering control device 1 also has an energization control unit 67, a current sensor 68, and an angle calculation unit 69.

[0021] The target steering torque calculation unit 51 calculates the axial force torque T ａｆ The target steering torque calculation unit 51 takes in the axial torque T ａｆ Based on the target steering torque T ｈ ＊ Calculate the axial torque T ａｆ is the axial force acting on the steered shaft 22 converted into torque acting on the steering shaft 11. ａｆ The larger the absolute value of the target steering torque T ｈ ＊ The absolute value of becomes larger.

[0022] The torque feedforward control unit 52 performs processing to compensate for a delay in response due to the inertia of the steering device 2 and improve the response of the control. ｈ ＊ The torque feedforward control unit 52 takes in the target steering torque T ｈ ＊ Through the execution of the feedforward control based on ｆｆ１ The torque feedforward control unit 52 calculates, for example, the target steering torque T ｈ ＊ is differentiated twice and multiplied by the inertia of the steering device 2, thereby obtaining the first feedforward control torque T ｆｆ１The first feedforward control torque T ｆｆ１ is an inertia compensation value. The inertia is determined, for example, from a physical model of the steering device 2.

[0023] The torque feedback control unit 53 receives the steering torque T detected through the torque sensor 42. ｈ and the target steering torque T calculated by the target steering torque calculation unit 51. ｈ ＊ The torque feedback control unit 53 receives the steering torque T detected through the torque sensor 42. ｈ is the target steering torque T ｈ ＊ The steering torque T ｈ By executing the feedback control of the first feedback control torque T ｆｂ１ Calculate the following.

[0024] The first disturbance estimator 54 is for estimating and compensating for disturbance torque. The disturbance torque is a nonlinear torque that occurs as a disturbance in the steering device 2, which is an actual plant, and is a steering torque T other than the torque generated by the steering motor 31. ｈ The first disturbance estimator 54 is, for example, an Extended State Observer. The first disturbance estimator 54 derives a first disturbance torque T ｏｂ１ The nominal plant is a model that simulates the actual plant that is the actual control target, that is, the steering device 2. The first disturbance estimator 54 estimates the steering torque T ｈ and the assist torque T calculated by the first calculator 55. ａｓ The first disturbance estimator 54 takes in the steering torque T ｈ and assist torque T ａｓ Based on this, the first disturbance torque T ｏｂ１ Calculate the following.

[0025] The first calculator 55 calculates the first feedforward control torque T ｆｆ１and the first feedback control torque T calculated by the torque feedback control unit 53. ｆｂ１ and the first disturbance torque T calculated by the first disturbance estimator 54. ｏｂ１ The first computing unit 55 takes in the first feedforward control torque T ｆｆ１ and the first feedback control torque T ｆｂ１ and the first disturbance torque T ｏｂ１ By subtracting the assist torque T ａｓ Calculate the following.

[0026] The second calculator 56 calculates the steering torque T ｈ and the assist torque T calculated by the first calculator 55. ａｓ The second calculator 56 calculates the steering torque T ｈ and assist torque T ａｓ By adding these, the input torque T ｉｎ Calculate the input torque T ｉｎ is the torque applied to the steering shaft 11.

[0027] The target angle calculation unit 61 calculates the input torque T ｉｎ and the axial torque T calculated by the axial torque calculation unit 62. ａｆ The target angle calculation unit 61 takes in the input torque T ｉｎ and axial torque T ａｆ Based on the target pinion angle θ ｐ ＊ Calculate the target pinion angle θ ｐ ＊ is the pinion angle θ, which is the rotation angle of the pinion shaft 21 ｐ This is the target value.

[0028] The target angle calculation unit 61 calculates the input torque T ｉｎ The axial torque T calculated by the axial torque calculation unit 62 from ａｆ By subtracting the ｉｎThe target angle calculation unit 61 calculates the target pinion angle θ using a model expressed by the following equation (1), for example. ｐ ＊ The model calculates the input torque T ｉｎ The ideal pinion angle θ when a torque equivalent to ｐ This is a model of the above.

[0029] T ｉｎ = J θ ｐ ＊ ''+C・θ ｐ ＊ '+K・θ ｐ ＊ ... (1) where "J" is an inertia coefficient that models the moment of inertia of the steering device 2. "C" is a viscosity coefficient that models the friction of the steering device 2. "K" is a spring coefficient that models the specifications of the suspension and wheel alignment of the vehicle on which the steering device 2 is mounted, assuming them as springs. The inertia coefficient J, viscosity coefficient C, and spring coefficient K are values ​​that correspond to the vehicle speed V detected by the vehicle speed sensor 41. "θ ｐ ＊ '' is the target pinion angle θ ｐ ＊ is the second time derivative of θ ｐ ＊ ' is the target pinion angle θ ｐ ＊ The symbol "·" in equation (1) indicates multiplication.

[0030] The current sensor 68 is provided on the power supply path between the current control unit 67 and the steering motor 31. The current sensor 68 detects the current I supplied to the steering motor 31. ｂ The axial force torque calculation unit 62 detects the target pinion angle θ calculated by the target angle calculation unit 61. ｐ ＊ and the current I of the steering motor 31 detected through the current sensor 68. ｂ and the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２ The axial force torque calculation unit 62 takes in the target pinion angle θ ｐ ＊ and the current I of the steering motor 31ｂ and the second disturbance torque T ｏｂ２ The axial force torque calculation unit 62 calculates the axial force acting on the steered shaft 22 based on the calculated axial force. The axial force torque calculation unit 62 converts the calculated axial force into a torque acting on the steering shaft 11, thereby calculating the axial force torque T ａｆ The axial force torque calculation unit 62 will be described in detail later.

[0031] The angle feedforward control unit 63 performs processing to compensate for a delay in response due to the inertia of the steering device 2 and improve the response of the control. ｐ ＊ The angle feedforward control unit 63 takes in the target pinion angle θ ｐ ＊ Through the execution of feedforward control based on ｆｆ２ The angle feedforward control unit 63 calculates, for example, the target pinion angle θ ｐ ＊ is differentiated twice and multiplied by the inertia of the steering device 2, thereby obtaining the second feedforward control torque T ｆｆ２ The second feedforward control torque T ｆｆ２ is an inertia compensation value. The inertia is determined, for example, from a physical model of the steering device 2.

[0032] The angle calculation unit 69 calculates the rotation angle θ of the steering motor 31 detected by the rotation angle sensor 43. ｂ Based on this, the pinion angle θ ｐ Calculate the pinion angle θ ｐ is the rotation angle of the pinion shaft 21. The angle calculation unit 69 calculates, for example, the rotation angle θ ｂ is divided by the reduction ratio from the pinion shaft 21 to the transmission mechanism 32 to obtain the pinion angle θ ｐ Calculate the following.

[0033] The angle feedback control unit 64 receives the target pinion angle θ calculated by the target angle calculation unit 61. ｐ ＊ and the pinion angle θ calculated by the angle calculation unit 69.ｐ The angle feedback control unit 64 receives the pinion angle θ calculated by the angle calculation unit 69. ｐ is the target pinion angle θ ｐ ＊ The pinion angle θ ｐ By executing the feedback control of the second feedback control torque T ｆｂ２ Calculate the following.

[0034] The second disturbance estimator 65 is for estimating and compensating for disturbance torque. The disturbance torque is a nonlinear torque that occurs as a disturbance in the steering device 2, which is an actual plant, and is a torque other than the torque generated by the steering motor 31 and the torque generated by the pinion angle θ ｐ , and thus the steering angle θ ｗ The second disturbance estimator 65 is, for example, an extended state observer. The second disturbance estimator 65 derives a second disturbance torque T based on the nominal plant. ｏｂ２ The nominal plant is a model that simulates the actual plant that is the actual control target, that is, the steering device 2. The second disturbance estimator 65 estimates the pinion angle θ calculated by the angle calculation unit 69. ｐ and the assist torque command value T calculated by the third calculator 66. ａｓ ＊ The second disturbance estimator 65 takes in the pinion angle θ ｐ and the assist torque command value T ａｓ ＊ Based on this, the second disturbance torque T ｏｂ２ Calculate the following.

[0035] The third calculator 66 calculates the second feedforward control torque T ｆｆ２ and the second feedback control torque T calculated by the angle feedback control unit 64. ｆｂ２ and the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２ The third calculator 66 calculates the second feedforward control torque T ｆｆ２ and the second feedback control torque T ｆｂ２ and the second disturbance torque Tｏｂ２ The assist torque command value T ａｓ ＊ Assist torque command value T ａｓ ＊ is the target value of the torque to be generated by the steering motor 31.

[0036] The power supply control unit 67 receives the assist torque command value T ａｓ ＊ The power supply control unit 67 receives the assist torque command value T ａｓ ＊ That is, the power supply control unit 67 supplies the steering motor 31 with electric power according to the assist torque command value T ａｓ ＊ The current command value is a target value of the current to be supplied to the steering motor 31. The current control unit 67 calculates a current command value based on the current I ｂ and the detected current I ｂ The current control unit 67 executes a feedback control based on the current command value and the current I detected by the current sensor 68. ｂ The power supply to the steering motor 31 is controlled so as to eliminate the calculated deviation. ａｓ ＊ A torque corresponding to the

[0037] <Configuration of Axial Force Torque Calculation Unit 62> Next, a detailed description will be given of the configuration of the axial force torque calculation unit 62. As shown in Fig. 3, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, a current axial force calculation unit 62C, a second filter 62D, a fourth calculator 62E, a fifth calculator 62F, and a mixed axial force calculation unit 62G.

[0038] The angle axial force calculation unit 62A calculates the target pinion angle θ calculated by the target angle calculation unit 61. ｐ ＊ The angle axial force calculation unit 62A takes in the target pinion angle θ ｐ ＊The angular axial force F1 is calculated based on the target pinion angle θ ｐ ＊ This is an ideal axial force that does not reflect the road surface condition or the force acting on the steered shaft 22 via the steered wheels 6. ｐ ＊ The absolute value of the angular axial force F1 may be set to increase as the absolute value of the target pinion angle θ increases. ｐ ＊ The angular axial force F1 increases linearly with an increase in the absolute value of the target pinion angle θ ｐ ＊ However, the angular axial force calculation unit 62A calculates the angular axial force F1 as a value converted into torque on the steering shaft 11.

[0039] The angular axial force calculation unit 62A may calculate the angular axial force F1 taking into consideration the vehicle speed V. In this case, the absolute value of the angular axial force F1 is calculated based on the target pinion angle θ ｐ ＊ The angle axial force calculation unit 62A may be configured to increase as the absolute value of the target pinion angle θ increases or as the vehicle speed V decreases. ｐ ＊ Instead, the pinion angle θ ｐ or steering angle θ ｓ The pinion angle θ ｐ or steering angle θ ｓ The angular axial force F1 may be calculated using the

[0040] The first filter 62B is a filter for estimating the second disturbance torque T ｏｂ２ The disturbance torque T ｏｂ２ The first filter 62B includes, for example, a band-pass filter. The first filter 62B includes, for example, a frequency component of various vibrations depending on the road surface condition. ｏｂ２ That is, the first filter 62B performs the first signal processing on the second disturbance torque T ｏｂ２The first filter 62B extracts frequency components that are important for the steering feel from the first filter 62B. The frequency components that are important for the steering feel are, for example, frequency components of vibrations that occur between the road surface and the steered wheels 6 that are necessary for the driver of the vehicle to recognize the road surface condition or the grip state of the steered wheels 6 on the road surface. The frequency components extracted by the first filter 62B are the first adjustment amount F2 for adjusting the angular axial force F1.

[0041] The fourth calculator 62E takes in the angular axial force F1 calculated by the angular axial force calculator 62A and the first adjustment amount F2, which is a frequency component extracted by the first filter 62B. The fourth calculator 62E adds the first adjustment amount F2 to the angular axial force F1 to calculate a final angular axial force F3. The final angular axial force F3 is calculated based on the axial force torque T ａｆ This is the final angular axial force used in the calculation of (a) and is the angular axial force that reflects the road surface condition that the driver of the vehicle should recognize.

[0042] The current axial force calculation unit 62C calculates the current I of the steering motor 31 detected through the current sensor 68. ｂ The current axial force calculation unit 62C takes in the current I of the steering motor 31. ｂ The current axial force F4 is calculated based on the value of the current I of the steering motor 31. ｂ This is an axial force that reflects the road surface condition or the force acting on the steering shaft 22 via the steering wheels 6. ｂ The value of the target pinion angle θ is determined based on disturbances depending on the road surface condition, such as road friction resistance acting on the steered wheels 6. ｐ ＊ and the actual pinion angle θ ｐ That is, the current I of the steering motor 31 ｂ The value of reflects the actual road surface condition acting on the steered wheels 6. Therefore, the current I of the steering motor 31 ｂ The current axial force calculation unit 62C calculates an axial force that reflects the influence of the road surface condition based on the value of the current I of the steering motor 31. The current axial force calculation unit 62C calculates a gain, which is a coefficient corresponding to the vehicle speed V, based on the value of the current I of the steering motor 31. ｂThe current axial force F4 is calculated by multiplying the value of the current axial force F4 by the value of the torque acting on the steering shaft 11. However, the current axial force F4 includes a viscosity component and a friction component of the steering device 2. The friction and viscosity of the steering device 2 are information that does not need to be transmitted to the driver of the vehicle. Furthermore, the current axial force calculation unit 62C calculates the current axial force F4 as a value converted into torque acting on the steering shaft 11.

[0043] The second filter 62D is a filter for estimating the second disturbance torque T ｏｂ２ The disturbance torque T ｏｂ２ The second filter 62D includes frequency components related to the friction and viscosity of the steering device 2 in addition to frequency components of various vibrations depending on the road surface condition. The second filter 62D has, for example, a low-pass filter. The second filter 62D filters out the second disturbance torque T ｏｂ２ That is, the second filter 62D performs second signal processing on the second disturbance torque T ｏｂ２ The second filter 62D extracts frequency components unnecessary for the steering feel from the second filter 62D. The frequency components unnecessary for the steering feel are, for example, frequency components related to the friction and viscosity of the steering device 2. The frequency component extracted by the second filter 62D is a second adjustment amount F5 for adjusting the current axial force F4.

[0044] The fifth calculator 62F receives the current axial force F4 calculated by the current axial force calculator 62C and the second adjustment amount F5, which is an unnecessary frequency component extracted by the second filter 62D. The fifth calculator 62F calculates a final current axial force F6 by subtracting the second adjustment amount F5 from the current axial force F4. The final current axial force F6 is calculated based on the axial torque T ａｆ This is the final current axial force used in the calculation of (a), and is the current axial force from which the viscous component and the friction component of the steering device 2 have been removed.

[0045] The mixed axial force calculation unit 62G takes in the final angular axial force F3 calculated by the fourth calculator 62E and the final current axial force F6 calculated by the fifth calculator 62F. The mixed axial force calculation unit 62G calculates a mixed axial force obtained by mixing the final angular axial force F3 and the final current axial force F6 at a predetermined ratio as an axial force torque T ａｆThe mixed axial force calculation unit 62G individually sets the distribution ratios for the final angular axial force F3 and the final current axial force F6 in accordance with various state variables that reflect the vehicle behavior, road surface conditions, or steering state. The state variables include, for example, the steering angle θ ｓ Alternatively, the vehicle speed V is included. The mixed axial force calculation unit 62G calculates the axial force torque T ａｆ The allocation ratio is set within the range of 0% to 100%. The sum of the allocation ratio for the final angular axial force F3 and the allocation ratio for the final current axial force F6 is 100%.

[0046] <Functions and Effects of the First Embodiment> The first embodiment provides the following functions and effects: (1-1) Target Pinion Angle θ ｐ ＊ The angular axial force F1 calculated based on the second disturbance estimator 65 is a robust axial force that is not easily affected by external disturbances, that is, an axial force that does not include road information to be transmitted to the driver of the vehicle. The road information is information that indicates the state of the road surface. In addition, the second disturbance torque T ｏｂ２ The road information includes road information to be transmitted to the driver of the vehicle. The road information includes, for example, information required for the driver of the vehicle to recognize the road surface condition or the grip state of the steered wheels 6 on the road surface.

[0047] Therefore, the second disturbance torque T ｏｂ２ The road information to be transmitted to the driver of the vehicle is extracted from the final angular axial force F3, and the extracted road information is added to the angular axial force F1. This makes it possible to superimpose only the road information to be transmitted to the driver of the vehicle on the robust angular axial force F1. By using the final angular axial force F3 that includes the road information, the assist torque command value T ａｓ ＊ Therefore, the assist torque command value T ａｓ＊ By applying an assist force to the steering wheel 5 according to the road surface condition, the driver of the vehicle can feel an appropriate response according to the road surface condition. Also, the driver of the vehicle can recognize the road surface condition as a response via the steering wheel 5.

[0048] The second disturbance torque T ｏｂ２ Extracting the frequency components important to the steering feel from the second disturbance torque T ｏｂ２ The addition of the first adjustment amount F2 to the angular axial force F1 corresponds to the extraction of road information to be transmitted to the driver of the vehicle. ｏｂ２ and adding a frequency component important to the steering feel extracted from the second disturbance torque T ｏｂ２ The load information extracted from the equation (1) is applied to the angular axial force F1.

[0049] (1-2) Current I of the steering motor 31 ｂ The current axial force F4 calculated based on the value of includes road information that should be transmitted to the vehicle driver and unnecessary information that does not need to be transmitted to the vehicle driver. The unnecessary information is, for example, the viscosity component and friction component of the steering device 2. The friction and viscosity of the steering device 2 are information that does not need to be transmitted to the vehicle driver. In addition, the second disturbance torque T calculated by the second disturbance estimator 65 ｏｂ２ includes the viscous component and the friction component of the steering device 2.

[0050] Therefore, the second disturbance torque T ｏｂ２ The viscosity component and the friction component of the steering device 2 are extracted from the current axial force F4, and the extracted viscosity component and friction component are subtracted from the current axial force F4, thereby removing unnecessary information from the current axial force F4. By using the final current axial force F6 from which unnecessary information has been removed, the assist torque command value T ａｓ ＊ Therefore, the assist torque command value T ａｓ ＊By applying an assist force to the steering wheel 5 according to the road surface condition, it is possible to suppress the feeling of viscosity and friction of the steering device 2 from being transmitted to the driver of the vehicle. This makes it possible to provide the driver of the vehicle with a smooth steering feel according to the road surface condition.

[0051] The second disturbance torque T ｏｂ２ Extracting the viscous component and the friction component of the steering device 2 from the ｏｂ２ Extracting unnecessary frequency components for the steering feel from the current axial force F4 corresponds to extracting unnecessary information that does not need to be transmitted to the driver of the vehicle from the disturbance torque. Subtracting the second adjustment amount F5 from the current axial force F4 corresponds to subtracting the viscosity component and friction component of the steering device 2 from the current axial force F4, and corresponds to removing unnecessary road information from the current axial force F4.

[0052] (1-3) The mixed axial force calculation unit 62G calculates the axial force torque T ａｆ The final angular axial force F3 is an axial force obtained by adding road information to be transmitted to the vehicle driver to the angular axial force F1, which does not include road information to be transmitted to the vehicle driver. The final current axial force F6 is an axial force obtained by removing unnecessary information that does not need to be transmitted to the vehicle driver from the current axial force F4, which includes unnecessary information that does not need to be transmitted to the vehicle driver. Therefore, no matter what ratio the final angular axial force F3 and the final current axial force F6 are mixed in, the axial force torque T ａｆ Also, the axial torque T ａｆ does not include unnecessary information that does not need to be transmitted to the driver of the vehicle. ａｆ The assist torque command value T ａｓ ＊ By applying an assist force to the steering wheel 5 according to the road surface condition, the driver of the vehicle can be given an appropriate steering feel according to the road surface condition.

[0053] Incidentally, if the angular axial force F1 and the current axial force F4 are used as they are to control the steering motor 31, the following concerns arise. ｐ ＊ On the other hand, the angular axial force F1 acts to cancel out the road information. For this reason, for example, if the distribution ratio of the angular axial force F1 is "100%" and the distribution ratio of the current axial force F4 is "0%," even if reverse input vibration occurs due to the road surface condition or a disturbance such as braking, the actual steering angle θ ｗ is the target pinion angle θ ｐ ＊ The corresponding steering angle θ ｗ That is, the steering of the steering wheel 5 is assisted in a direction that cancels the reverse input vibration, thereby suppressing the transmission of the reverse input vibration to the steering wheel 5. Therefore, it becomes difficult for the driver of the vehicle to recognize the road surface condition through the steering wheel 5.

[0054] The current axial force F4 is used to transmit road information to the driver of the vehicle. However, the current axial force F4 includes unnecessary information that does not need to be transmitted to the driver of the vehicle, such as the friction component and the viscosity component of the steering device 2. For this reason, for example, if the distribution ratio of the angle axial force F1 is "0%" and the distribution ratio of the current axial force F4 is "100%," there is a risk that the driver of the vehicle will be given a sense of viscosity and friction as information via the steering wheel 5.

[0055] Therefore, the axial force torque T is a mixed axial force in which the angular axial force F1 and the current axial force F4 are mixed together. ａｆ is used to control the steering motor 31, the following phenomenon may occur. That is, if the distribution ratio of the angular axial force F1 is larger than the distribution ratio of the current axial force F4, it may be difficult to transmit road information to the driver of the vehicle. Conversely, if the distribution ratio of the current axial force F4 is larger than the distribution ratio of the angular axial force F1, it may be possible to transmit unnecessary information to the driver of the vehicle. According to this embodiment, it is possible to solve such a trade-off.

[0056] (1-4) The axial force torque calculation unit 62 calculates the second disturbance torque T ｏｂ２ The angle axial force F1 and the current axial force F4 are adjusted using the above formula. Therefore, unlike when the steering control device 1 has an individual compensation function for the current axial force F4, complicated constant design is not required. The compensation function includes a friction compensation function and a viscosity compensation function. Furthermore, since the steering control device 1 does not have an individual compensation function for the current axial force F4, it is advantageous in terms of CPU resources.

[0057] Second Embodiment Next, a second embodiment of the steering control device will be described. This embodiment differs from the first embodiment in the configuration of the axial force torque calculation unit 62. Therefore, the same members and configurations as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0058] 4, a configuration is adopted in which the current axial force calculation section 62C, the second filter 62D, the fifth calculator 62F, and the mixed axial force calculation section 62G are omitted as the axial force torque calculation section 62. That is, the axial force torque calculation section 62 has an angle axial force calculation section 62A, a first filter 62B, and a fourth calculator 62E.

[0059] The angle axial force calculation unit 62A calculates the target pinion angle θ ｐ ＊ The first filter 62B calculates the angular axial force F1 based on the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２ The fourth calculator 62E extracts a frequency component that is important for the steering feel from the angle axial force F1 and sets it as a first adjustment amount F2 for the angle axial force F1. The fourth calculator 62E calculates the final angle axial force F3 by adding the first adjustment amount F2 to the angle axial force F1. ａｆ It is calculated as:

[0060] The target steering torque calculation unit 51 receives the angular axial force F1 calculated by the angular axial force calculation unit 62A, and calculates the target steering torque T ｈ ＊ However, the target steering torque calculation unit 51 calculates the axial torque T ａｆThe target steering torque T is calculated based on the final angular axial force F3 as ｈ ＊ may be calculated.

[0061] According to this embodiment, the same effects as those of the first embodiment (1-1) can be obtained. <Third embodiment> Next, a third embodiment of the steering control device will be described. In this embodiment, the configuration of the axial force torque calculation unit 62 differs from that of the first embodiment. For this reason, the same members and configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0062] 5, a configuration is adopted in which the angle axial force calculation section 62A, the first filter 62B, the fourth calculator 62E, and the mixed axial force calculation section 62G are omitted as the axial force torque calculation section 62. That is, the axial force torque calculation section 62 has a current axial force calculation section 62C, a second filter 62D, and a fifth calculator 62F.

[0063] The current axial force calculation unit 62C calculates the current I of the steering motor 31. ｂ The second filter 62D calculates the current axial force F4 based on the value of the second disturbance torque T ｏｂ２ The fifth calculator 62F extracts frequency components unnecessary for the steering feel from the current axial force F4 and sets the extracted frequency components as a second adjustment amount F5 for the current axial force F4. The fifth calculator 62F calculates the final current axial force F6 by subtracting the second adjustment amount F5 from the current axial force F4. ａｆ It is calculated as:

[0064] The target steering torque calculation unit 51 receives the current axial force F4 calculated by the current axial force calculation unit 62C, and calculates the target steering torque T ｈ ＊ However, the target steering torque calculation unit 51 calculates the axial torque T ａｆ The target steering torque T ｈ ＊ may be calculated.

[0065] According to this embodiment, the same effect as that of (1-2) in the first embodiment can be obtained. <Fourth embodiment> Next, a fourth embodiment of the steering control device will be described. In this embodiment, the configuration of the axial force torque calculation unit 62 and the second disturbance torque T ｏｂ２ The second embodiment differs from the first embodiment in that the state variables corrected based on the state variables are different from the first embodiment. Therefore, the same members and configurations as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0066] 6, the axial force torque calculation unit 62 has a configuration in which the first filter 62B, the current axial force calculation unit 62C, the second filter 62D, the fourth calculator 62E, the fifth calculator 62F, and the mixed axial force calculation unit 62G are omitted. That is, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A. The first filter 62B is not a component of the axial force torque calculation unit 62, but exists as a component of the steering control device 1.

[0067] The angle axial force calculation unit 62A calculates the target pinion angle θ ｐ ＊ Based on this, the angular axial force F1 is converted into the axial torque T ａｆ The target steering torque calculation unit 51 calculates the axial force torque T calculated by the angle axial force calculation unit 62A. ａｆ The angular axial force F1 is taken in as the target steering torque T ｈ ＊ The first filter 62B calculates the second disturbance torque T ｏｂ２ The frequency components important to the steering feel are extracted from the target steering torque T ｈ ＊ is defined as the first adjustment amount F2.

[0068] The steering control device 1 has a sixth calculator 71. The sixth calculator 71 calculates the target steering torque T ｈ ＊ and the first adjustment amount F2, which is the frequency component extracted by the first filter 62B. ｈ ＊By adding the first adjustment amount F2 to the final target steering torque T ｈｈ ＊ The final target steering torque T ｈｈ ＊ is the final target steering torque used to control the steering motor 31, and is the target steering torque that reflects the road surface condition that the driver of the vehicle should recognize.

[0069] The torque feedforward control unit 52 receives the final target steering torque T ｈｈ ＊ The torque feedforward control unit 52 takes in the final target steering torque T ｈｈ ＊ A first feedforward control torque T ｆｆ１ Calculate the following.

[0070] The torque feedback control unit 53 receives the steering torque T detected through the torque sensor 42. ｈ and the final target steering torque T calculated by the sixth calculator 71. ｈｈ ＊ The torque feedback control unit 53 receives the steering torque T detected through the torque sensor 42. ｈ is the final target steering torque T ｈｈ ＊ The steering torque T ｈ By executing the feedback control of the first feedback control torque T ｆｂ１ Calculate the following.

[0071] This embodiment has the following functions and effects: (2-1) Target pinion angle θ ｐ ＊ The angular axial force F1 calculated based on the angle axial force F1 is a robust axial force that is not easily affected by external disturbances, that is, an axial force that does not include road information to be transmitted to the driver of the vehicle. ｈ ＊ In contrast, the second disturbance torque T calculated by the second disturbance estimator 65 does not include road information to be transmitted to the driver of the vehicle.ｏｂ２ The second disturbance torque T ｏｂ２ The road information to be transmitted to the driver of the vehicle is extracted from the target steering torque T ｈ ＊ As a result, the target steering torque T ｈ ＊ Only the road information to be transmitted to the driver of the vehicle can be superimposed on the final target steering torque T ｈｈ ＊ By using the above, the assist torque command value T ａｓ ＊ Therefore, the assist torque command value T ａｓ ＊ By applying an assist force to the steering wheel 5 according to the road surface condition, the driver of the vehicle can feel an appropriate response according to the road surface condition. Also, the driver of the vehicle can recognize the road surface condition as a response via the steering wheel 5.

[0072] <Fifth embodiment> Next, a fifth embodiment of the steering control device will be described. This embodiment differs from the fourth embodiment in the configuration of the axial force torque calculation unit 62. Therefore, the same members and configurations as those in the fourth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0073] 7, the axial force torque calculation unit 62 has a current axial force calculation unit 62C instead of the angle axial force calculation unit 62A. Also, the steering control device 1 has a second filter 62D instead of the first filter 62B.

[0074] The current axial force calculation unit 62C calculates the current I of the steering motor 31. ｂ Based on the value of ａｆ The target steering torque calculation unit 51 calculates the axial force torque T ａｆThe current axial force F4 is taken in as the target steering torque T ｈ ＊ The second filter 62D calculates the second disturbance torque T ｏｂ２ The frequency components unnecessary for the steering feel are extracted from the target steering torque T ｈ ＊ is the second adjustment amount F5.

[0075] The sixth calculator 71 calculates the target steering torque T ｈ ＊ and a second adjustment amount F5, which is a frequency component extracted by the second filter 62D. ｈ ＊ By subtracting the second adjustment amount F5 from the ｈｈ ＊ The final target steering torque T ｈｈ ＊ is the final target steering torque used to control the steering motor 31, and is the target steering torque from which the viscous component and friction component of the steering device 2 have been removed.

[0076] <Functions and Effects of Fifth Embodiment> The fifth embodiment provides the following functions and effects. (3-1) Current I of the steering motor 31 ｂ The current axial force F4 calculated based on the value of the current axial force F4 includes road information that should be transmitted to the vehicle driver and unnecessary information that does not need to be transmitted to the vehicle driver. ｈ ＊ The second disturbance torque T calculated by the second disturbance estimator 65 includes road information that should be transmitted to the vehicle driver and unnecessary information that does not need to be transmitted to the vehicle driver. The unnecessary information is, for example, the viscosity component and friction component of the steering device 2. ｏｂ２ contains the viscous component and the friction component of the steering device 2. Therefore, the second disturbance torque T ｏｂ２The viscosity component and friction component of the steering device 2 are extracted from the target steering torque T ｈ ＊ This subtracts the target steering torque T ｈ ＊ The target steering torque T from which unnecessary information has been removed can be calculated. ｈ ＊ By using the above, the viscosity component and the friction component of the steering device 2 are reduced, and the assist torque command value T ａｓ ＊ Therefore, the assist torque command value T ａｓ ＊ By applying an assist force to the steering wheel 5 according to the road surface condition, it is possible to suppress the feeling of viscosity and friction of the steering device 2 from being transmitted to the driver of the vehicle. This makes it possible to provide the driver of the vehicle with a smooth steering feel according to the road surface condition.

[0077] <Sixth embodiment> Next, a sixth embodiment of the steering control device will be described. This embodiment differs from the first embodiment in the configuration of the steering control device 1. Therefore, the same members and configurations as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0078] 8, the steering control device 1 has an assist torque calculation unit 81, a third filter 82, a seventh calculator 83, and a second disturbance estimator 65. The second disturbance estimator 65 is the same as that in the first embodiment.

[0079] The assist torque calculation unit 81 calculates the steering torque T ｈ The assist torque calculation unit 81 takes in the steering torque T ｈ Based on the assist torque T ａｓ Assist torque T ａｓ is the assist torque command value T ａｓ ＊ The assist torque T is the basis for calculating the torque in the same direction as the steering direction of the steering wheel 5. ａｓ The absolute value of the steering torque Tｈ The larger the absolute value of

[0080] The assist torque calculation unit 81 calculates the assist torque T ａｓ In this case, the assist torque T ａｓ The absolute value of the steering torque T ｈ The larger the absolute value of , or the slower the vehicle speed V, the larger the value may be.

[0081] The third filter 82 filters the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２ The first signal processing is performed on the second disturbance torque T ｏｂ２ The frequency components that are important for the steering feel are extracted from the ａｓ The second signal processing is a process of adjusting the second disturbance torque T ｏｂ２ frequency components that are unnecessary for the steering feel are extracted from the ａ This is a process of setting the second adjustment amount F5 for the above.

[0082] When the third filter 82 performs the first signal processing, the seventh calculator 83 calculates the assist torque T ａｓ and the first adjustment amount F2. The seventh calculator 83 calculates the assist torque T ａｓ By adding the first adjustment amount F2 to the assist torque command value T ａｓ ＊ As a result, the assist torque command value T ａｓ ＊ is obtained.

[0083] When the third filter 82 performs the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ and the second adjustment amount F5. The seventh calculator 83 calculates the assist torque T ａｓ By subtracting the second adjustment amount F5 from ａｓ ＊As a result, unnecessary information, i.e., the viscous component and the friction component of the steering device 2 are reduced, and the assist torque command value T ａｓ ＊ is obtained.

[0084] When the third filter 82 performs both the first signal processing and the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ The seventh calculator 83 receives the first adjustment amount F2 and the second adjustment amount F5. ａｓ The assist torque command value T ａｓ ＊ However, the seventh calculator 83 calculates the assist torque T ａｓ The assist torque command value T ａｓ ＊ In this way, the assist torque command value T ａｓ ＊ is obtained.

[0085] <Functions and Effects of the Sixth Embodiment> The sixth embodiment provides the following functions and effects: (4-1) The steering torque T detected by the torque sensor 42 ｈ does not include road information to be transmitted to the driver of the vehicle. When the third filter 82 performs the first signal processing, the seventh calculator 83 calculates the assist torque T ａｓ and the first adjustment amount F2. The first adjustment amount F2 is calculated by subtracting the second disturbance torque T ｏｂ２ The seventh calculator 83 extracts and calculates the frequency components that are important for the steering feel from the assist torque T ａｓ By adding the first adjustment amount F2 to the assist torque command value T ａｓ ＊ As a result, the assist torque command value T ａｓ ＊ Therefore, the assist torque command value Tａｓ ＊ By applying an assist force to the steering wheel 5 according to the road surface condition, the driver of the vehicle can feel an appropriate response according to the road surface condition. Also, the driver of the vehicle can recognize the road surface condition as a response via the steering wheel 5.

[0086] (4-2) Steering torque T detected through torque sensor 42 ｈ The seventh calculator 83 calculates the assist torque T ａｓ and the second adjustment amount F5. The second adjustment amount F5 is calculated by subtracting the second disturbance torque T ｏｂ２ The seventh calculator 83 calculates the assist torque T ａｓ By subtracting the second adjustment amount F5 from ａｓ ＊ As a result, unnecessary information, i.e., the viscous component and the friction component of the steering device 2 are reduced, and the assist torque command value T ａｓ ＊ Therefore, the assist torque command value T ａｓ ＊ By applying an assist force to the steering wheel 5 according to the road surface condition, it is possible to suppress the feeling of viscosity and friction of the steering device 2 from being transmitted to the driver of the vehicle. This makes it possible to provide the driver of the vehicle with a smooth steering feel according to the road surface condition.

[0087] (4-3) When the third filter 82 performs both the first signal processing and the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ The seventh calculator 83 receives the first adjustment amount F2 and the second adjustment amount F5. ａｓ The assist torque command value T ａｓ ＊As a result, the assist torque command value T ａｓ ＊ Therefore, the assist torque command value T ａｓ ＊ By applying an assist force to the steering wheel 5 according to the assist torque command value T ａｓ ＊ By applying an assist force to the steering wheel 5 according to the steering force, it is possible to prevent the viscous and frictional sensations of the steering device 2 from being transmitted to the driver of the vehicle.

[0088] <Seventh embodiment> Next, a seventh embodiment of a steering control device will be described. This embodiment differs from the sixth embodiment in the configuration of the steering control device 1. Therefore, the same members and configurations as those in the sixth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0089] As shown in FIG. 9 , the steering control device 1 has an assist torque calculation unit 81, an eighth calculator 84, a target angle calculation unit 61, an axial force torque calculation unit 62, an angle feedforward control unit 63, an angle feedback control unit 64, a second disturbance estimator 65, and a third calculator 66.

[0090] The assist torque calculation unit 81 is the same as that of the sixth embodiment shown in Fig. 8. The third filter 82 in the sixth embodiment is omitted. The target angle calculation unit 61, the angle feedforward control unit 63, the angle feedback control unit 64, the second disturbance estimator 65, and the third calculator 66 are the same as those of the first embodiment shown in Fig. 2.

[0091] The assist torque calculation unit 81 calculates the steering torque T ｈ Based on the assist torque T ａｓ The eighth calculator 84 calculates the assist torque T ａｓ and the steering torque T detected by the torque sensor 42. ｈThe eighth calculator 84 calculates the assist torque T ａｓ and steering torque T ｈ By adding these, the input torque T ｉｎ Calculate the following.

[0092] The axial force torque calculation unit 62 is similar to that of the second embodiment shown in Fig. 4. That is, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, and a fourth calculator 62E.

[0093] The angle axial force calculation unit 62A calculates the target pinion angle θ ｐ ＊ The first filter 62B calculates the angular axial force F1 based on the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２ The fourth calculator 62E extracts a frequency component that is important for the steering feel from the angle axial force F1 and sets it as a first adjustment amount F2 for the angle axial force F1. The fourth calculator 62E calculates the final angle axial force F3 by adding the first adjustment amount F2 to the angle axial force F1. ａｆ It is calculated as:

[0094] The target angle calculation unit 61 calculates the input torque T ｉｎ and the axial torque T calculated by the axial torque calculation unit 62. ａｆ The target angle calculation unit 61 takes in the input torque T ｉｎ and axial torque T ａｆ Based on the target pinion angle θ ｐ ＊ Calculate the following.

[0095] According to this embodiment, the same effects as those of the first embodiment (1-1) can be obtained. <Eighth embodiment> Next, an eighth embodiment of a steering control device will be described. This embodiment differs from the seventh embodiment in the configuration of the axial force torque calculation unit 62. For this reason, the same members and configurations as those of the seventh embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0096] As shown in FIG. 10, the axial force torque calculation unit 62 has a current axial force calculation unit 62C, a second filter 62D, and a fifth calculator 62F, similar to the third embodiment shown in FIG.

[0097] The current axial force calculation unit 62C calculates the current I of the steering motor 31. ｂ The second filter 62D has the same function as the third filter 82 of the sixth embodiment shown in FIG. 8. That is, the second filter 62D calculates the current axial force F4 based on the value of the second disturbance torque T ｏｂ２ The first signal processing is performed on the second disturbance torque T ｏｂ２ The frequency components that are important for the steering feel are extracted from the ａｓ The second signal processing is a process of adjusting the second disturbance torque T ｏｂ２ frequency components that are unnecessary for the steering feel are extracted from the ａ This is a process of setting the second adjustment amount F5 for the above.

[0098] The fifth calculator 62F has the same calculation function as the seventh calculator 83 of the sixth embodiment shown in Fig. 8. That is, when the second filter 62D performs the first signal processing, the fifth calculator 62F takes in the current axial force F4 and the first adjustment amount F2. The fifth calculator 62F calculates the final current axial force F6 as the axial torque T by adding the first adjustment amount F2 to the current axial force F4. ａｆ As a result, the assist torque command value T ａｓ ＊ is obtained.

[0099] When the second filter 62D performs the second signal processing, the fifth calculator 62F takes in the current axial force F4 and the second adjustment amount F5. The fifth calculator 62F calculates the final current axial force F6 as the axial torque T by subtracting the second adjustment amount F5 from the current axial force F4. ａｆ As a result, unnecessary information, i.e., the assist torque command value T ａｓ ＊ is obtained.

[0100] When the second filter 62D performs both the first signal processing and the second signal processing, the fifth calculator 62F takes in the current axial force F4, the first adjustment amount F2, and the second adjustment amount F5. The fifth calculator 62F calculates the final current axial force F6 as the axial torque T by subtracting the second adjustment amount F5 from the value obtained by adding the first adjustment amount F2 to V. ａｆ However, the fifth calculator 62F calculates the final current axial force F6 as the axial torque T by adding the first adjustment amount F2 to the value obtained by subtracting the second adjustment amount F5 from the current axial force F4. ａｆ In this way, the road information is amplified and the viscous and frictional components of the steering device 2 are reduced to obtain the assist torque command value T ａｓ ＊ is obtained.

[0101] The target angle calculation unit 61 calculates the input torque T ｉｎ and the axial torque T calculated by the axial torque calculation unit 62. ａｆ The target angle calculation unit 61 takes in the input torque T ｉｎ and axial torque T ａｆ Based on the target pinion angle θ ｐ ＊ Calculate the following.

[0102] According to this embodiment, the same effects as those of (4-1), (4-2), and (4-3) of the sixth embodiment shown in Fig. 8 can be obtained. The eighth embodiment may be implemented in combination with the seventh embodiment. In this case, the axial force torque calculator 62 has a configuration similar to that of the first embodiment shown in Fig. 3. That is, the axial force torque calculator 62 has an angle axial force calculator 62A, a first filter 62B, a current axial force calculator 62C, a second filter 62D, a fourth calculator 62E, a fifth calculator 62F, and a mixed axial force calculator 62G.

[0103] <Ninth embodiment> Next, a ninth embodiment of the steering control device will be described. This embodiment differs from the first embodiment in that the steering device 2 that is the control target of the steering control device 1 is not an electric power steering device, but a steer-by-wire steering device 2. The steer-by-wire steering device 2 basically has the same configuration as the electric power steering device shown in Fig. 1. For this reason, the same members and configurations as those in the first embodiment are assigned the same reference numerals, and detailed description thereof will be omitted.

[0104] <Configuration of steering device 2> As shown in Fig. 11, the steer-by-wire steering device 2 has a steering mechanism 3 and a turning mechanism 4. However, the steering mechanism 3 and the turning mechanism 4 are mechanically separated so that mechanical power transmission is not possible.

[0105] The steering mechanism 3 has a steering shaft 11, a reaction motor 12, and a reducer 13. The reaction motor 12 is a source of a steering reaction force applied to the steering shaft 11. The steering reaction force is a force in a direction opposite to the steering direction of the steering wheel 5. The reaction motor 12 is, for example, a three-phase brushless motor. The reducer 13 is provided closer to the second end of the steering shaft 11 than the torque sensor 42. The second end is an end opposite to the first end of the steering shaft 11 to which the steering wheel 5 is connected. The reducer 13 reduces the speed of rotation of the reaction motor 12 and transmits the reduced rotation to the steering shaft 11.

[0106] Similar to the first embodiment, the steering mechanism 4 has a pinion shaft 21, a steered shaft 22, and a housing 23. However, the pinion shaft 21 and the steering shaft 11, i.e., the steering wheel 5 and the steered wheels 6, are mechanically separated so that mechanical power transmission is not possible. Also, similar to the first embodiment, the steering mechanism 4 has a steering motor 31, a transmission mechanism 32, and a conversion mechanism 33. However, the steering motor 31 is a source of the steering force applied to the steered shaft 22. The steering force is a force for steering the steered wheels 6.

[0107] The steering control device 1 receives detection results from sensors mounted on the vehicle. The sensors include a vehicle speed sensor 41, a torque sensor 42, and two rotation angle sensors 43 and 44. The rotation angle sensor 44 is provided on the reaction force motor 12. The rotation angle sensor 44 detects the rotation angle θ of the reaction force motor 12. ａ The rotation angle θ of the reaction motor 12 is detected. ａ is a positive value when the steering wheel 5 is steered to the right, and is a negative value when the steering wheel 5 is steered to the left, for example.

[0108] The steering control device 1 executes reaction force control. The steering control device 1 controls the operation of the reaction force motor 12 using the detection results of the vehicle speed sensor 41, the torque sensor 42, and the rotation angle sensor 44. The steering control device 1 controls the steering torque T ｈ The power supply to the reaction force motor 12 is controlled so that the reaction force motor 12 generates a steering reaction force corresponding to the steering reaction force.

[0109] The steering control device 1 executes steering control. The steering control device 1 controls the operation of the steering motor 31 using the detection result of the rotation angle sensor 43. The steering control device 1 controls the power supply to the steering motor 31 so that the steered wheels 6 are steered in accordance with the steering state of the steering wheel 5.

[0110] <Configuration of steering control device 1> As shown in Fig. 12, the steering control device 1 has a reaction force control unit 1A and a turning control unit 1B. The control object of reaction force control unit 1A is the steering mechanism 3. Reaction force control unit 1A executes reaction force control. The control object of turning control unit 1B is the steering mechanism 4. Turning control unit 1B executes steering control.

[0111] <Reaction Force Control Unit 1A> The reaction force control unit 1A basically has the same configuration as the first embodiment shown in Fig. 2. That is, the reaction force control unit 1A has a target steering torque calculation unit 51, a torque feedforward control unit 52, a torque feedback control unit 53, a first disturbance estimator 54, a first calculator 55, and a second calculator 56. The reaction force control unit 1A also has a target angle calculation unit 61, an axial force torque calculation unit 62, an angle feedforward control unit 63, an angle feedback control unit 64, a second disturbance estimator 65, and a third calculator 66. The steering control device 1 also has an energization control unit 67, a current sensor 68, and an angle calculation unit 69. The reaction force control unit 1A further has a target pinion angle calculation unit 70.

[0112] The target steering torque calculation unit 51 calculates the target steering torque T based on the angle axial force F1 calculated by the axial force torque calculation unit 62. ｈ ＊ However, the target steering torque calculation unit 51 calculates the axial force torque T ａｆ Based on the target steering torque T ｈ ＊ The following may be calculated.

[0113] The torque feedforward control unit 52 calculates the target steering torque T ｈ ＊ Through the execution of the feedforward control based on ｆｆ１ The torque feedback control unit 53 calculates the steering torque T ｈ is the target steering torque T ｈ ＊ The steering torque T ｈ By executing the feedback control of the first feedback control torque T ｆｂ１ Calculate the following.

[0114] The first disturbance estimator 54 calculates the steering torque T ｈ and assist torque T ａｓ Based on this, the first disturbance torque T ｏｂ１The first calculator 55 calculates the first feedforward control torque T ｆｆ１ and the first feedback control torque T ｆｂ１ and the first disturbance torque T ｏｂ１ By subtracting the assist torque T ａｓ Calculate the following.

[0115] The second calculator 56 calculates the steering torque T ｈ and assist torque T ａｓ By adding these, the input torque T ｉｎ The target angle calculation unit 61 calculates the input torque T ｉｎ and axial torque T ａｆ Based on this, the target steering angle θ ｓ ＊ Calculate the target steering angle θ ｓ ＊ is the steering angle θ, which is the rotation angle of the steering wheel 5 ｓ The target angle calculation unit 61 calculates the input torque T ｉｎ The axial torque T calculated by the axial torque calculation unit 62 from ａｆ By subtracting the ｉｎ The target angle calculation unit 61 calculates the final input torque T based on the ideal model expressed by the following equation (2): ｉｎ to target steering angle θ ｓ ＊ In the ideal model, when it is assumed that the steering wheel 5 and the steered wheels 6 are mechanically connected, the input torque T ｉｎ The ideal steering angle θ ｗ The steering angle θ of the steering wheel 5 corresponding to ｓ This is a model of the above.

[0116] T ｉｎ = J θ ｓ ＊ ''+C・θ ｓ ＊ '+K・θ ｓ ＊... (2) where "J" is an inertia coefficient that models the moment of inertia of the steering device 2. "C" is a viscosity coefficient that models the friction of the steering device 2. "K" is a spring coefficient that models the specifications of the suspension and wheel alignment of the vehicle on which the steering device 2 is mounted, assuming them as springs. The inertia coefficient J, viscosity coefficient C, and spring coefficient K are values ​​that correspond to the vehicle speed V detected by the vehicle speed sensor 41. "θ ｓ ＊ '' is the target steering angle θ ｓ ＊ is the second time derivative of θ ｓ ＊ ' is the target steering angle θ ｓ ＊ The symbol "·" in equation (2) indicates multiplication.

[0117] The target pinion angle calculation unit 70 calculates the target steering angle θ calculated by the target angle calculation unit 61. ｓ ＊ The target pinion angle calculation unit 70 takes in the target steering angle θ ｓ ＊ Based on the target pinion angle θ ｐ ＊ The target pinion angle calculation unit 70 calculates the target pinion angle θ so as to realize a steering angle ratio set according to product specifications, etc. ｐ ＊ The steering angle ratio is calculated by the steering angle θ ｓ steering angle θ ｗ is the ratio of

[0118] The axial force torque calculation unit 62 has a configuration similar to that of the second embodiment shown in Fig. 4. That is, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, and a fourth calculator 62E. The angle axial force calculation unit 62A calculates the target pinion angle θ ｐ ＊ The first filter 62B calculates the angular axial force F1 based on the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２The fourth calculator 62E extracts a frequency component that is important for the steering feel from the angle axial force F1 and sets it as a first adjustment amount F2 for the angle axial force F1. The fourth calculator 62E calculates the final angle axial force F3 by adding the first adjustment amount F2 to the angle axial force F1. ａｆ It is calculated as:

[0119] The angle feedforward control unit 63 performs processing to compensate for a delay in response due to the inertia of the steering device 2 and improve the response of the control. ｐ ＊ The angle feedforward control unit 63 takes in the target pinion angle θ ｐ ＊ Through the execution of feedforward control based on ｆｆ２ Calculate the following.

[0120] The angle calculation unit 69 calculates the rotation angle θ of the reaction force motor 12 detected by the rotation angle sensor 44. ａ Based on this, the steering angle θ of the steering wheel 5 ｓ Calculate the steering angle θ ｓ is the rotation angle of the steering wheel 5. The angle calculation unit 69 calculates, for example, the rotation angle θ ａ is divided by the reduction ratio of the reducer 13 to obtain the steering angle θ ｓ Calculate the following.

[0121] The angle feedback control unit 64 controls the target steering angle θ calculated by the target angle calculation unit 61. ｓ ＊ and the steering angle θ calculated by the angle calculation unit 69. ｓ The angle feedback control unit 64 receives the steering angle θ calculated by the angle calculation unit 69. ｓ is the target steering angle θ ｓ ＊ The steering angle θ ｓ By executing the feedback control of the second feedback control torque T ｆｂ２ Calculate the following.

[0122] The second disturbance estimator 65 is for estimating and compensating for disturbance torque. The disturbance torque is a nonlinear torque that occurs as a disturbance in the steering device 2, which is an actual plant, and is a torque other than the torque generated by the reaction motor 12 when the steering angle θ ｓ The second disturbance estimator 65 is, for example, an extended state observer. The second disturbance estimator 65 derives a second disturbance torque T based on the nominal plant. ｏｂ２ The nominal plant is a model that simulates the actual plant that is the actual control target, that is, the steering device 2. The second disturbance estimator 65 estimates the steering angle θ calculated by the angle calculation unit 69. ｓ and the reaction torque command value T calculated by the third calculator 66. ｓ ＊ The second disturbance estimator 65 takes in the steering angle θ ｓ and the reaction torque command value T ｓ ＊ Based on this, the second disturbance torque T ｏｂ２ Calculate the following.

[0123] The third calculator 66 calculates the second feedforward control torque T ｆｆ２ and the second feedback control torque T ｆｂ２ and the second disturbance torque T ｏｂ２ By subtracting the reaction torque command value T ｓ ＊ The reaction torque command value T ｓ ＊ is the torque to be generated by the reaction motor 12, i.e., the target value of the steering reaction force.

[0124] The current sensor 68 is provided on the power supply path between the current control unit 67 and the reaction motor 12. The current sensor 68 detects the current I supplied to the reaction motor 12. ａ The current control unit 67 detects the reaction torque command value T ｓ ＊ The power supply control unit 67 receives the reaction torque command value T ｓ ＊ That is, the power supply control unit 67 supplies the reaction motor 12 with electric power according to the reaction torque command value T ｓ＊ The current command value is a target value of the current to be supplied to the reaction motor 12. The current control unit 67 calculates a current I ａ and the detected current I ａ The current control unit 67 executes a feedback control based on the current command value and the current I detected by the current sensor 68. ａ The reaction force motor 12 is controlled to supply power to the reaction force motor 12 so as to eliminate the calculated deviation. ｓ ＊ A torque corresponding to the

[0125] <Steering control section 1B> Steering control section 1B has a second angle feedforward control section 91, a second angle feedback control section 92, a third disturbance estimator 93, and a ninth calculator 94. Steering control section 1B also has an energization control section 95, a current sensor 96, and an angle calculation section 97.

[0126] The second angle feedforward control unit 91 performs processing to compensate for a delay in response due to the inertia of the steering device 2 and improve the response of the control. The second angle feedforward control unit 91 performs processing to compensate for a delay in response due to the inertia of the steering device 2 and improve the response of the control. ｐ ＊ The second angle feedforward control unit 91 takes in the target pinion angle θ ｐ ＊ Through the execution of the feedforward control based on ｆｆ３ Calculate the following.

[0127] The angle calculation unit 97 calculates the rotation angle θ of the steering motor 31 detected by the rotation angle sensor 43. ｂ Based on this, the pinion angle θ ｐ The second angle feedback control unit 92 calculates the target pinion angle θ calculated by the target pinion angle calculation unit 70. ｐ ＊ and the pinion angle θ calculated by the angle calculation unit 97. ｐThe second angle feedback control unit 92 receives the pinion angle θ calculated by the angle calculation unit 97. ｐ is the target pinion angle θ ｐ ＊ The pinion angle θ ｐ By executing the feedback control of the third feedback control torque T ｆｂ３ Calculate the following.

[0128] The third disturbance estimator 93 is for estimating and compensating for disturbance torque. The disturbance torque is a nonlinear torque that occurs as a disturbance in the steering device 2, which is an actual plant, and is a torque other than the torque generated by the steering motor 31, which is a torque that is generated by the pinion angle θ ｐ The third disturbance estimator 93 is, for example, an extended state observer. The third disturbance estimator 93 derives a third disturbance torque T based on the nominal plant. ｏｂ３ The nominal plant is a model that simulates the actual plant that is the actual control target, that is, the steering device 2. The third disturbance estimator 93 estimates the pinion angle θ calculated by the angle calculation unit 97. ｐ and the steering torque command value T calculated by the ninth calculator 94. w ＊ The third disturbance estimator 93 takes in the pinion angle θ ｐ and the steering torque command value T w ＊ Based on this, the third disturbance torque T ｏｂ３ Calculate the following.

[0129] The ninth calculator 94 calculates the third feedforward control torque T ｆｆ３ and the third feedback control torque T calculated by the second angle feedback control unit 92. ｆｂ３ and the third disturbance torque T calculated by the third disturbance estimator 93. ｏｂ３ The ninth calculator 94 calculates the third feedforward control torque T ｆｆ３ and the third feedback control torque T ｆｂ３ and the third disturbance torque T ｏｂ３The steering torque command value T w ＊ The steering torque command value T w ＊ is the torque to be generated by the steering motor 31, i.e., the target value of the steering force.

[0130] The current sensor 96 is provided on the power supply path between the current supply control unit 95 and the steering motor 31. The current sensor 96 detects the current I supplied to the steering motor 31. ｂ The current supply control unit 95 detects the turning torque command value T w ＊ The current supply control unit 95 receives the steering torque command value T w ＊ That is, the power supply control unit 95 supplies the steering motor 31 with electric power according to the steering torque command value T w ＊ The current command value is a target value of the current to be supplied to the steering motor 31. The current control unit 95 calculates a current command value based on the current I ｂ and the detected current I ｂ The current control unit 95 executes a feedback control based on the current command value and the current I detected by the current sensor 96. ｂ The power supply to the steering motor 31 is controlled so as to eliminate the deviation. w ＊ A torque corresponding to the

[0131] <Functions and Effects of the Ninth Embodiment> (5-1) The axial force torque calculation unit 62 has the same configuration as that of the second embodiment shown in Fig. 4. That is, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, and a fourth calculator 62E. Therefore, the following effects can be obtained.

[0132] Target pinion angle θ ｐ ＊The angular axial force F1 calculated based on the third disturbance estimator 93 is a robust axial force that is not easily affected by external disturbances, that is, an axial force that does not include road information to be transmitted to the driver of the vehicle. The road information is information that indicates the state of the road surface. In contrast, the third disturbance torque T ｏｂ３ The third disturbance torque T ｏｂ３ The road information to be transmitted to the driver of the vehicle is extracted from the angular axial force F1, and the extracted road information is added to the angular axial force F1. This makes it possible to superimpose only the road information to be transmitted to the driver of the vehicle on the robust angular axial force F1. The final angular axial force F3 including the road information is added to the axial torque T ａｆ By using it as a reaction torque command value T ｓ ＊ Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force according to the road surface condition to the steering wheel 5, the driver of the vehicle can be given an appropriate sense of response according to the road surface condition. Also, the driver of the vehicle can recognize the road surface condition as a response via the steering wheel 5.

[0133] (5-2) Depending on the product use, the axial force torque calculation unit 62 may have a configuration similar to that of the third embodiment shown in Fig. 5. In this case, the axial force torque calculation unit 62 has a current axial force calculation unit 62C, a second filter 62D, and a fifth calculator 62F. In this way, the following effects can be obtained.

[0134] That is, the current I of the steering motor 31 ｂThe current axial force F4 calculated based on the value of includes road information that should be transmitted to the vehicle driver and unnecessary information that does not need to be transmitted to the vehicle driver. The unnecessary information is, for example, the viscosity component and friction component of the steering device 2. The friction and viscosity of the steering device 2 are information that does not need to be transmitted to the vehicle driver. In addition, the third disturbance torque T calculated by the third disturbance estimator 93 ｏｂ３ contains the viscous component and the friction component of the steering device 2. Therefore, the third disturbance torque T ｏｂ３ The viscosity component and the friction component of the steering device 2 are extracted from the current axial force F4, and the extracted viscosity component and friction component are subtracted from the current axial force F4, thereby removing unnecessary information from the current axial force F4. The final current axial force F6 from which unnecessary information has been removed is calculated as the axial torque T ａｆ By using the reaction torque command value T ｓ ＊ Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force according to the road surface condition to the steering wheel 5, it is possible to prevent the driver of the vehicle from feeling the viscosity and friction of the steering mechanism 4. This makes it possible to provide the driver of the vehicle with a smooth steering feel according to the road surface condition.

[0135] (5-3) Depending on the product use, the axial force torque calculation unit 62 may have a configuration similar to that of the first embodiment shown in Fig. 3. In this case, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, a current axial force calculation unit 62C, a second filter 62D, a fourth calculator 62E, a fifth calculator 62F, and a mixed axial force calculation unit 62G. In this way, the following effects can be obtained.

[0136] That is, the mixed axial force calculation unit 62G calculates the axial force torque T ａｆThe final angular axial force F3 is an axial force obtained by adding road information to be transmitted to the vehicle driver to the angular axial force F1, which does not include road information to be transmitted to the vehicle driver. The final current axial force F6 is an axial force obtained by removing unnecessary information that does not need to be transmitted to the vehicle driver from the current axial force F4, which includes unnecessary information that does not need to be transmitted to the vehicle driver. Therefore, no matter what ratio the final angular axial force F3 and the final current axial force F6 are mixed in, the axial force torque T ａｆ Also, the axial torque T ａｆ does not include unnecessary information that does not need to be transmitted to the driver of the vehicle. ａｆ The reaction torque command value T ｓ ＊ By applying a steering reaction force to the steering wheel 5 according to the road surface condition, the driver of the vehicle can be given an appropriate steering feel according to the road surface condition.

[0137] (5-4) Depending on product use, the axial force torque calculation unit 62 may have a configuration similar to that of the fourth embodiment shown in FIG. 6. In this case, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A. The first filter 62B is not a component of the axial force torque calculation unit 62, but exists as a component of the reaction force control unit 1A. The reaction force control unit 1A also has a sixth calculator 71. The sixth calculator 71 calculates the target steering torque T ｈ ＊ By adding the first adjustment amount F2 to the final target steering torque T ｈｈ ＊ The first adjustment amount F2 is a frequency component that is important for the steering feel, and is, for example, a frequency component, among vibrations generated between the road surface and the steered wheels 6, that is required for the driver of the vehicle to recognize the road surface condition or the grip state of the steered wheels 6 on the road surface. In this way, it is possible to obtain the same effect as in (2-1) of the fourth embodiment shown in FIG. 6. Specifically, it is as follows.

[0138] That is, the target steering torque T ｈ＊ Only the road information to be transmitted to the driver of the vehicle can be superimposed on the final target steering torque T ｈｈ ＊ By using the above, the reaction torque command value T ｓ ＊ Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force according to the road surface condition to the steering wheel 5, the driver of the vehicle can be given an appropriate sense of response according to the road surface condition. Also, the driver of the vehicle can recognize the road surface condition as a response via the steering wheel 5.

[0139] (5-5) Depending on the product use, the axial force torque calculation unit 62 may have a configuration similar to that of the fifth embodiment shown in FIG. 7. In this case, the axial force torque calculation unit 62 has a current axial force calculation unit 62C. The reaction force control unit 1A also has a second filter 62D and a sixth calculator 71. The second filter 62D is not a component of the axial force torque calculation unit 62, but exists as a component of the reaction force control unit 1A. The sixth calculator 71 calculates the target steering torque T ｈ ＊ By subtracting the second adjustment amount F5 from the ｈｈ ＊ The second adjustment amount F5 is a frequency component that is unnecessary for the steering feel, for example, a frequency component related to the friction and viscosity of the steering device 2. In this way, it is possible to obtain the same effect as that of (3-1) of the fifth embodiment shown in FIG. 7. Specifically, it is as follows.

[0140] That is, the target steering torque T ｈ ＊ The target steering torque T from which unnecessary information has been removed can be calculated. ｈ ＊ By using the reaction torque command value T ｓ ＊Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force according to the road surface condition to the steering wheel 5, it is possible to suppress the feeling of viscosity and friction of the steering device 2 from being transmitted to the driver of the vehicle. This makes it possible to provide the driver of the vehicle with a smooth steering feel according to the road surface condition.

[0141] <Tenth embodiment> Next, a tenth embodiment of a steering control device will be described. This embodiment differs from the ninth embodiment in the configuration of a reaction force control unit 1A. Therefore, the same members and configurations as those in the ninth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0142] 13, the reaction force control unit 1A has an assist torque calculation unit 81, a third filter 82, and a seventh calculator 83. The reaction force control unit 1A also has a target pinion angle calculation unit 70, an angular axial force calculation unit 62A, and a tenth calculator 101.

[0143] The assist torque calculation unit 81 is the same as that of the sixth embodiment shown in FIG. ｈ Based on the assist torque T ａｓ The third filter 82 is the same as that in the sixth embodiment shown in FIG. 8. The third filter 82 calculates the second disturbance torque T ｏｂ２ The first signal processing is performed on the second disturbance torque T ｏｂ２ The frequency components that are important for the steering feel are extracted from the ａｓ The second signal processing is a process of adjusting the second disturbance torque T ｏｂ２ frequency components that are unnecessary for the steering feel are extracted from the ａｓ This is a process of setting the second adjustment amount F5 for the above.

[0144] The seventh calculator 83 is the same as that in the sixth embodiment shown in Fig. 8. When the third filter 82 performs the first signal processing, the seventh calculator 83 calculates the assist torque Tａｓ and the first adjustment amount F2. The seventh calculator 83 calculates the assist torque T ａｓ By adding the first adjustment amount F2 to the ａｓｓ As a result, the final assist torque T ａｓｓ The final assist torque T ａｓｓ is the reaction torque command value T ｓ ＊ The final assist torque T used in the calculation ａｓ is.

[0145] When the third filter 82 performs the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ and the second adjustment amount F5. The seventh calculator 83 calculates the assist torque T ａｓ By subtracting the second adjustment amount F5 from ａｓｓ As a result, unnecessary information, i.e., the final assist torque T ａｓｓ is obtained.

[0146] When the third filter 82 performs both the first signal processing and the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ The seventh calculator 83 receives the first adjustment amount F2 and the second adjustment amount F5. ａｓ The final assist torque T is calculated by adding the first adjustment amount F2 to the value obtained by subtracting the second adjustment amount F5. ａｓｓ However, the seventh calculator 83 calculates the assist torque T ａｓ The final assist torque T is calculated by subtracting the second adjustment amount F5 from the torque V and adding the first adjustment amount F2 to the result. ａｓｓ As a result, the final assist torque T ａｓｓ is obtained.

[0147] The target pinion angle calculation unit 70 is basically the same as that of the ninth embodiment shown in Fig. 12. However, the target pinion angle calculation unit 70 calculates the steering angle θ of the steering wheel 5 calculated by the angle calculation unit 69. ｓ The steering angle θ ｓ Based on the target pinion angle θ ｐ ＊ The angle calculation unit 69 is the same as that in the ninth embodiment shown in Fig. 12. However, for the sake of convenience, the angle calculation unit 69 is not shown in Fig. 13.

[0148] The angle axial force calculation unit 62A is the same as that of the ninth embodiment shown in Fig. 12. However, the angle axial force calculation unit 62A calculates the target pinion angle θ calculated by the target pinion angle calculation unit 70. ｐ ＊ The angle axial force calculation unit 62A takes in the target pinion angle θ ｐ ＊ Based on this, the angular axial force F1 is converted into the axial torque T ａｆ The angle axial force calculation unit 62A constitutes the axial force torque calculation unit 62.

[0149] The tenth calculator 101 calculates the final assist torque T ａｓｓ and the axial force torque T calculated by the angle axial force calculation unit 62A. ａｆ The tenth calculator 101 calculates the final assist torque T ａｓｓ From the axial torque T ａｆ By subtracting ｓ ＊ Calculate the following.

[0150] The reaction force control unit 1A has a current control unit 67. The current control unit 67 is the same as that of the ninth embodiment shown in FIG. 12. However, the current control unit 67 is configured to control the reaction force torque command value T ｓ ＊ The reaction torque command value T ｓ ＊ 13, the power according to the current sensor 68 is not shown in the figure.

[0151] Steering control unit 1B is similar to the ninth embodiment shown in Figure 12. Steering control unit 1B has a second angle feedforward control unit 91, a second angle feedback control unit 92, a third disturbance estimator 93, and a ninth calculator 94. For the sake of convenience of explanation, illustration of energization control unit 95, current sensor 96, angle calculation unit 97, and steering motor 31 is omitted in Figure 13.

[0152] <Operations and Effects of the Tenth Embodiment> The tenth embodiment has the following operations and effects: (6-1) The steering torque T detected by the torque sensor 42 ｈ does not include road information to be transmitted to the driver of the vehicle. When the third filter 82 performs the first signal processing, the seventh calculator 83 calculates the assist torque T ａｓ and the first adjustment amount F2. The first adjustment amount F2 is calculated by subtracting the second disturbance torque T ｏｂ２ The seventh calculator 83 extracts and calculates the frequency components that are important for the steering feel from the assist torque T ａｓ By adding the first adjustment amount F2 to the ａｓｓ The final assist torque T ａｓｓ is the assist torque T with road information ａｓ The tenth calculator 101 calculates the final assist torque T ａｓｓ From the axial torque T ａｆ By subtracting ｓ ＊ As a result, the reaction torque command value T ｓ ＊ Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force according to the road surface condition to the steering wheel 5, the driver of the vehicle can be given an appropriate sense of response according to the road surface condition. Also, the driver of the vehicle can recognize the road surface condition as a response via the steering wheel 5.

[0153] (6-2) Steering torque T detected through torque sensor 42ｈ The seventh calculator 83 calculates the assist torque T ａｓ and the second adjustment amount F5. The second adjustment amount F5 is calculated by subtracting the second disturbance torque T ｏｂ２ The seventh calculator 83 calculates the assist torque T ａｓ By subtracting the second adjustment amount F5 from ａｓｓ The final assist torque T ａｓｓ is the assist torque T with unnecessary information removed. ａｓ The tenth calculator 101 calculates the final assist torque T ａｓｓ From the axial torque T ａｆ By subtracting ｓ ＊ As a result, unnecessary information, i.e., the reaction torque command value T ｓ ＊ Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force according to the road surface condition to the steering wheel 5, it is possible to suppress the feeling of viscosity and friction of the steering device 2 from being transmitted to the driver of the vehicle. This makes it possible to provide the driver of the vehicle with a smooth steering feel according to the road surface condition.

[0154] (6-3) When the third filter 82 performs both the first signal processing and the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ The seventh calculator 83 receives the first adjustment amount F2 and the second adjustment amount F5. ａｓ The final assist torque T is calculated by adding the first adjustment amount F2 to the value obtained by subtracting the second adjustment amount F5. ａｓｓ The final assist torque T ａｓｓis the assist torque T ａｓ The tenth calculator 101 calculates the final assist torque T ａｓｓ From the axial torque T ａｆ By subtracting ｓ ＊ As a result, the reaction torque command value T ｓ ＊ Therefore, the reaction torque command value T ｓ ＊ By applying a steering reaction force to the steering wheel 5 according to the reaction torque command value T ｓ ＊ By applying an assist force to the steering wheel 5 according to the steering force, it is possible to prevent the viscous and frictional sensations of the steering device 2 from being transmitted to the driver of the vehicle.

[0155] (6-4) Depending on the product use, the angle axial force calculation unit 62A may be replaced with a current axial force calculation unit 62C. The current axial force calculation unit 62C is the same as that in the first embodiment shown in FIG. 3. The current axial force calculation unit 62C calculates the current I of the steering motor 31. ｂ Based on the value of ａｆ The tenth calculator 101 calculates the final assist torque T ａｓｓ From the axial torque T ａｆ By subtracting ｓ ＊ Even in this way, the reaction torque command value T ｓ ＊ , and the reaction torque command value T ｓ ＊ At least one of the above can be obtained.

[0156] <Eleventh embodiment> Next, an eleventh embodiment of a steering control device will be described. This embodiment differs from the tenth embodiment in the configuration of a reaction force control unit 1A. Therefore, the same members and configurations as those in the tenth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0157] 14, the reaction force control unit 1A has an assist torque calculation unit 81, a third filter 82, and a seventh calculator 83. The reaction force control unit 1A also has a target pinion angle calculation unit 70, an angle axial force calculation unit 62A, and a tenth calculator 101. The third filter 82, the angle axial force calculation unit 62A, and the seventh calculator 83 configure the axial force torque calculation unit 62.

[0158] The assist torque calculation unit 81 calculates the steering torque T ｈ Based on the assist torque T ａｓ The third filter 82 calculates the second disturbance torque T ｏｂ２ The first signal processing is performed on the second disturbance torque T ｏｂ２ The frequency components that are important for the steering feel are extracted from the ａｓ The second signal processing is a process of adjusting the second disturbance torque T ｏｂ２ frequency components that are unnecessary for the steering feel are extracted from the ａｓ This is a process of setting the second adjustment amount F5 for the above.

[0159] The target pinion angle calculation unit 70 calculates the steering angle θ of the steering wheel 5 calculated by the angle calculation unit 69. ｓ The steering angle θ ｓ Based on the target pinion angle θ ｐ ＊ Calculate the following.

[0160] The angle axial force calculation unit 62A calculates the target pinion angle θ calculated by the target pinion angle calculation unit 70. ｐ ＊ The target pinion angle θ ｐ ＊The angular axial force F1 is calculated based on the above.

[0161] When the third filter 82 performs the first signal processing, the seventh calculator 83 takes in the angular axial force F1 and the first adjustment amount F2. The seventh calculator 83 adds the first adjustment amount F2 to the angular axial force F1 to calculate the final angular axial force F3 as the axial force torque T ａｆ It is calculated as:

[0162] The tenth calculator 101 calculates the assist torque T ａｓ and axial torque T ａｆ The tenth computing unit 101 takes in the assist torque T ａｓ From the axial torque T ａｆ By subtracting ｓ ＊ As a result, the reaction torque command value T ｓ ＊ is obtained.

[0163] When the third filter 82 performs the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓ and the second adjustment amount F5. The seventh calculator 83 calculates the assist torque T ａｓ By subtracting the second adjustment amount F5 from the ａｆ It is calculated as:

[0164] The tenth calculator 101 calculates the assist torque T ａｓ and axial torque T ａｆ The tenth computing unit 101 takes in the assist torque T ａｓ From the axial torque T ａｆ By subtracting ｓ ＊ As a result, unnecessary information, i.e., the reaction torque command value T ｓ ＊ is obtained.

[0165] When the third filter 82 performs both the first signal processing and the second signal processing, the seventh calculator 83 calculates the assist torque T ａｓThe seventh calculator 83 receives the first adjustment amount F2 and the second adjustment amount F5. ａｓ The final angular axial force F3 is calculated by subtracting the second adjustment amount F5 from the value obtained by adding the first adjustment amount F2 to the torque T ａｆ However, the seventh calculator 83 calculates the assist torque T ａｓ The final angular axial force F3 is adjusted to the axial force torque T by adding the first adjustment amount F2 to the value obtained by subtracting the second adjustment amount F5 from the ａｆ It is calculated as:

[0166] The tenth calculator 101 calculates the assist torque T ａｓ and axial torque T ａｆ The tenth computing unit 101 takes in the assist torque T ａｓ From the axial torque T ａｆ By subtracting ｓ ＊ As a result, the reaction torque command value T ｓ ＊ is obtained.

[0167] Therefore, according to this embodiment, the same effects as those of (6-1) to (6-3) of the tenth embodiment can be obtained. Note that, depending on the product usage, the angle axial force calculation unit 62A may be replaced with the current axial force calculation unit 62C. In this case, the same effects as those of (6-4) of the tenth embodiment can be obtained.

[0168] <Twelfth embodiment> Next, a twelfth embodiment of the steering control device will be described. This embodiment differs from the ninth embodiment shown in Fig. 12 in the method of calculating the input torque Tin. Therefore, the same members and configurations as those in the ninth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0169] 15, the reaction force control unit 1A has an assist torque calculation unit 81 and an eighth calculator 84. The reaction force control unit 1A also has a target angle calculation unit 61, an axial force torque calculation unit 62, an angle feedforward control unit 63, an angle feedback control unit 64, a second disturbance estimator 65, and a third calculator 66. The reaction force control unit 1A further has a target pinion angle calculation unit 70.

[0170] The assist torque calculation unit 81 is the same as that of the sixth embodiment shown in FIG. ｈ Based on the assist torque T ａｓ The eighth calculator 84 calculates the assist torque T ａｓ and the steering torque T detected by the torque sensor 42. ｈ The eighth calculator 84 calculates the assist torque T ａｓ and steering torque T ｈ By adding these, the input torque T ｉｎ Calculate the following.

[0171] The axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, and a fourth calculator 62E. The angle axial force calculation unit 62A calculates the target pinion angle θ ｐ ＊ The first filter 62B calculates the angular axial force F1 based on the second disturbance torque T calculated by the second disturbance estimator 65. ｏｂ２ The fourth calculator 62E extracts a frequency component that is important for the steering feel from the angle axial force F1 and sets it as a first adjustment amount F2 for the angle axial force F1. The fourth calculator 62E calculates the final angle axial force F3 by adding the first adjustment amount F2 to the angle axial force F1. ａｆ It is calculated as:

[0172] The target angle calculation unit 61 calculates the input torque T ｉｎ and the axial torque T calculated by the axial torque calculation unit 62. ａｆ The target angle calculation unit 61 takes in the input torque T ｉｎ and axial torque T ａｆ Based on this, the target steering angle θ ｓ＊ Calculate the following.

[0173] According to this embodiment, the same effect as that of (5-1) of the ninth embodiment can be obtained. Note that, depending on the product use, the axial force torque calculation unit 62 may have a configuration similar to that of the third embodiment shown in FIG. 5. In this case, the axial force torque calculation unit 62 has a current axial force calculation unit 62C, a second filter 62D, and a fifth calculator 62F. In this way, the same effect as that of (5-2) of the ninth embodiment can be obtained.

[0174] Depending on the product use, the axial force torque calculation unit 62 may have a configuration similar to that of the first embodiment shown in Fig. 3. In this case, the axial force torque calculation unit 62 has an angle axial force calculation unit 62A, a first filter 62B, a current axial force calculation unit 62C, a second filter 62D, a fourth calculator 62E, a fifth calculator 62F, and a mixed axial force calculation unit 62G. In this way, the same effect as that of (5-3) of the ninth embodiment can be obtained.

[0175] Other Embodiments Each embodiment may be modified as follows: The target angle calculation unit 61 and the target pinion angle calculation unit 70 may calculate the target pinion angle θ ｐ ＊ The target steering angle may be calculated instead of the steering angle θ ｗ The target point steering angle is, for example, a target pinion angle θ ｐ ＊ is obtained by multiplying by a predetermined conversion coefficient.

[0176] The first disturbance estimator 54, the second disturbance estimator 65, and the third disturbance estimator 93 do not need to be extended state observers. The first disturbance estimator 54, the second disturbance estimator 65, and the third disturbance estimator 93 may estimate disturbances based on other models, such as an extended Kalman filter or an internal control model. For example, the extended Kalman filter can compensate for the viscosity and stiffness of the steering device 2.

[0177] The steering control device 1 may change the magnitudes of the first adjustment amount F2 and the second adjustment amount F5 used for control by multiplying the first adjustment amount F2 and the second adjustment amount F5 by, for example, a gain. The value of the gain may change depending on the vehicle speed V or the steering angular velocity. The first adjustment amount F2 is calculated based on the second disturbance torque T ｏｂ２ The second adjustment amount F5 is a frequency component extracted from the second disturbance torque T ｏｂ２ These are frequency components extracted from the steering wheel, which are unnecessary for the steering feel. In this way, the steering feel given to the driver of the vehicle can be adjusted.

[0178] The filter constants of the first filter 62B, the second filter 62D, and the third filter 82 may vary depending on the vehicle speed V or the steering angular velocity. If the vehicle has an automatic driving function, the steering feel provided to the driver of the vehicle may be adjusted between automatic driving and manual driving. For example, in the first embodiment, during automatic driving, the first adjustment amount F2 and the second adjustment amount F5 are multiplied by a gain of "0." This causes the amount of road information added to the angular axial force F1 to be "0." Furthermore, the amount of unnecessary information subtracted from the current axial force F4 to be "0." Incidentally, the automatic driving function includes a driving assistance function. During driving assistance, the gain values ​​by which the first adjustment amount F2 and the second adjustment amount F5 are multiplied may be changed within a range of "0" to "1." The gain values ​​are changed, for example, based on the degree of system intervention in steering.

[0179] The shape of the steering wheel 5, which is an operator, is not limited to a circular shape. The steering wheel 5 may be, for example, D-shaped or U-shaped. In the ninth to twelfth embodiments, the operator is not limited to the steering wheel 5. The operator may be, for example, a lever. The steering control device 1 controls the steering angle θ according to the tilt angle of the lever. ｗ The steering control device 1 controls the steering motor 31 so as to realize the above. The steering control device 1 also controls an actuator that applies a reaction force to the lever in response to the operation of the lever.

[0180] The ninth to twelfth embodiments are not limited to front-wheel steering devices, and may be applied to rear-wheel steering devices or four-wheel steering devices.Furthermore, the ninth to twelfth embodiments may be applied to a front-wheel independent steering device that independently controls the left and right front wheels, or a four-wheel independent steering device that independently controls four wheels.

[0181] In this specification, "at least one of A and B" means "A only, B only, or both A and B." <Notes> The steering control device 1 described in each embodiment can be understood, for example, as follows.

[0182] 1. A steering control device (1) according to a first aspect controls a steering device (2) having a motor (31, 12) that generates torque to be applied to an operator (5) of a vehicle, and calculates a torque command value (T ａｓ ＊ , T ｓ ＊ The steering control device is configured to control the motor based on a disturbance estimator (65), a first processing unit (62B, 62D, 82), and a second processing unit (62E, 62F, 71, 83). The disturbance estimator uses a model simulating the steering device to estimate a disturbance torque (T ｏｂ２ The first processing unit is configured to generate adjustment amounts (F2, F5) for adjusting the torque command value based on the disturbance torque calculated by the disturbance estimator. The second processing unit is configured to apply the adjustment amounts generated by the first processing unit to state variables (F1, F4, T ｈ ＊ , T ａｓ ) is configured to reflect the

[0183] According to this configuration, the torque command value is adjusted by reflecting the adjustment amount calculated based on the disturbance torque in the state variables that are the basis for calculating the torque command value. By controlling the motor based on this torque command value, an appropriate torque is applied to the operator. In other words, an appropriate steering feel can be given to the driver of the vehicle via the operator.

[0184] Steering wheel 5 corresponds to an operator. First filter 62B, second filter 62D, and third filter 83 correspond to a first processing unit. Fourth calculator 62E, fifth calculator 62F, sixth calculator 71, and seventh calculator 83 correspond to a second processing unit. Steering motor 31 corresponds to a motor that affects the steered wheels.

[0185] Angle axial force F1, current axial force F4, target steering torque T ｈ ＊ , assist torque T ａｓ is a state variable that is the basis for calculating the torque command value. ｈ is a state variable that reflects the operation state of the operator. ａｓ ＊ and the reaction torque command value T ｓ ＊ correspond to torque command values.

[0186] 2. A steering control device according to a second aspect is based on the steering control device according to the first aspect. The operating element and the steered wheels are connected so as to be capable of transmitting power. The motor is a steering motor (31) that generates an assist force to be applied to a steering shaft (22) that steers the steered wheels.

[0187] With this configuration, the torque command value is adjusted by reflecting the adjustment amount calculated based on the disturbance torque in the state variables that form the basis for calculating the torque command value. By controlling the steering motor based on this torque command value, an appropriate torque is applied to the operator. In other words, an appropriate steering feel can be given to the driver of the vehicle via the operator.

[0188] 3. A steering control device according to a third aspect is based on the steering control device according to the second aspect, and the state variables are axial forces (F1, F4) acting on the steered shaft, which are calculated based on the steered state of the steered wheels.

[0189] Target pinion angle θ ｐ ＊ and the current I of the steering motor 31 ｂ The values ​​of are state variables that reflect the steering state of the steered wheels. With this configuration, the adjustment amount calculated based on the disturbance torque is reflected in the axial force calculated based on the steering state of the steered wheels, thereby adjusting the torque command value.

[0190] 4. A steering control device according to a fourth aspect is based on the steering control device according to the third aspect. The axial force is a target rotation angle (θ ｐ ＊ ) and the current (I ｂ and a current axial force (F4) calculated based on the value of the current axial force (F5).

[0191] According to this configuration, the adjustment amount calculated based on the disturbance torque is reflected in at least one of the angular axial force and the current axial force, thereby adjusting the torque command value. 5. A steering control device according to a fifth aspect is based on the steering control device according to the fourth aspect. The first processing unit is configured to determine the adjustment amount by extracting, from the disturbance torque, a frequency component that is important for steering feel, when the state variable includes the angular axial force. The second processing unit is configured to add the adjustment amount to the angular axial force when the state variable includes the angular axial force.

[0192] According to this configuration, road information to be transmitted to the vehicle driver is extracted from the disturbance torque, and the extracted road information is imparted to the angular axial force. This makes it possible to superimpose only the road information to be transmitted to the vehicle driver on the angular axial force. By using this angular axial force, it is possible to obtain a torque command value to which road information is imparted. Note that extracting frequency components important to the steering feel from the disturbance torque means extracting road information to be transmitted to the vehicle driver from the disturbance torque. Adding an adjustment amount to the angular axial force means imparting the road information extracted from the disturbance torque to the angular axial force.

[0193] 6. A steering control device according to a sixth aspect is based on the steering control device according to the fourth aspect. The first processing unit is configured to calculate the adjustment amount by extracting, from the disturbance torque, frequency components unnecessary for steering feel when the state variable includes the current axial force. The second processing unit is configured to subtract the adjustment amount from the current axial force when the state variable includes the current axial force.

[0194] According to this configuration, unnecessary information that does not need to be transmitted to the vehicle driver is extracted from the disturbance torque, and the extracted unnecessary road information is removed from the current axial force. By using this current axial force, it is possible to obtain a torque command value in which unnecessary information is reduced. Note that extracting frequency components that are unnecessary for steering feel from the disturbance torque means extracting unnecessary information from the disturbance torque that does not need to be transmitted to the vehicle driver. Subtracting the adjustment amount from the current axial force means removing unnecessary road information from the current axial force.

[0195] 7. A steering control device according to a seventh aspect is based on the steering control device according to the second aspect. The state variable is a target steering torque of the operator calculated based on an axial force acting on the steered shaft. The axial force is an angular axial force calculated based on a target rotation angle of a pinion shaft that rotates in conjunction with the steered shaft. The first processing unit is configured to determine the adjustment amount by extracting, from the disturbance torque, frequency components that are important for steering feel. The second processing unit is configured to add the adjustment amount to the target steering torque.

[0196] With this configuration, road information to be communicated to the vehicle driver can be imparted to the target steering torque. 8. A steering control device according to an eighth aspect is based on the steering control device according to the second aspect. The state variable is the target steering torque of the operator calculated based on the axial force acting on the steered shaft. The axial force is a current axial force calculated based on the value of the current of the steering motor. The first processing unit is configured to determine the adjustment amount by extracting frequency components unnecessary for steering feel from the disturbance torque. The second processing unit is configured to subtract the adjustment amount from the target steering torque.

[0197] According to this configuration, it is possible to remove unnecessary information that does not need to be communicated to the driver of the vehicle from the target steering torque. 9. A steering control device according to a ninth aspect is based on the steering control device according to the second aspect. The state variable is an assist torque, which is a torque in the same direction as the operation direction of the operator, calculated based on the operation state of the operator. The first processing unit is configured to execute at least one of first signal processing that determines the adjustment amount by extracting frequency components that are important for the steering feel from the disturbance torque, and second signal processing that determines the adjustment amount by extracting frequency components that are unnecessary for the steering feel from the disturbance torque. The second processing unit is configured to add the adjustment amount to the assist torque when the first signal processing is executed, and to subtract the adjustment amount from the assist torque when the second signal processing is executed.

[0198] With this configuration, it is possible to obtain at least one of an assist torque to which road information to be transmitted to the vehicle driver has been added and an assist torque from which unnecessary information that does not need to be transmitted to the vehicle driver has been removed. By calculating a torque command value using this assist torque, it is possible to obtain at least one of a torque command value to which road information to be transmitted to the vehicle driver has been added and a torque command value from which unnecessary information that does not need to be transmitted to the vehicle driver has been removed.

[0199] 10. A steering control device according to a tenth aspect is based on the steering control device according to the first aspect. The operator (5) and the steered wheels (6) are mechanically separated so that mechanical power transmission is not possible. The motor includes a reaction motor (12) that generates a steering reaction force to be applied to the operator (5), and a steering motor (31) that generates a steering force to be applied to a steering shaft (22) that steers the steered wheels (6). The steering control device is configured to generate a reaction torque command value (T ｓ ＊ ) and a steering torque command value (T ｗ ＊ and a steering control unit (1B) configured to control the steering motor based on the disturbance torque (T ｏｂ２ ) is a torque that affects the steered wheels and is other than the torque generated by the steering motor. The reaction force control unit has the first processing unit (62B, 62D, 82) and the second processing unit (62E, 62F, 71, 83). The first processing unit is configured to generate adjustment amounts (F2, F5) for adjusting the reaction torque command value based on the disturbance torque calculated by the disturbance estimator. The second processing unit is configured to reflect the adjustment amounts generated by the first processing unit in state variables that are the basis for calculating the reaction torque command value.

[0200] According to this configuration, the reaction torque command value is adjusted by reflecting the adjustment amount calculated based on the disturbance torque in the state variables that are the basis for calculating the reaction torque command value. By controlling the reaction motor based on this reaction torque command value, an appropriate reaction torque is applied to the operator. In other words, a more appropriate steering feel can be given to the driver of the vehicle via the operator.

[0201] 11. A steering control device according to an eleventh aspect is based on the steering control device according to the tenth aspect. The state variable is an axial force acting on the steered shaft, and is calculated based on the steered state of the steered wheels.

[0202] According to this configuration, the adjustment amount calculated based on the disturbance torque is reflected in the axial force calculated based on the steered state of the steered wheels, thereby making it possible to adjust the reaction torque command value.

[0203] 12. A steering control device according to a twelfth aspect is based on the steering control device according to the eleventh aspect. The axial force includes at least one of an angle axial force calculated based on a target rotation angle of a pinion shaft that rotates in conjunction with the steered shaft, and a current axial force calculated based on a value of a current of the steered motor.

[0204] According to this configuration, the adjustment amount calculated based on the disturbance torque is reflected in at least one of the angular axial force and the current axial force, thereby adjusting the reaction torque command value. 13. A steering control device according to a thirteenth aspect is based on the steering control device according to the twelfth aspect. The first processing unit is configured to determine the adjustment amount by extracting, from the disturbance torque, a frequency component that is important for steering feel, when the state variable includes the angular axial force. The second processing unit is configured to add the adjustment amount to the angular axial force when the state variable includes the angular axial force.

[0205] According to this configuration, road information to be transmitted to the vehicle driver is extracted from the disturbance torque, and the extracted road information is imparted to the angular axial force. This makes it possible to superimpose only the road information to be transmitted to the vehicle driver on the angular axial force. By using this angular axial force, it is possible to obtain a reaction torque command value to which the road information has been imparted.

[0206] 14. A steering control device according to a fourteenth aspect is based on the steering control device according to the twelfth aspect. The first processing unit is configured to, when the state variable includes the current axial force, calculate the adjustment amount by extracting, from the disturbance torque, frequency components unnecessary for steering feel. The second processing unit is configured to, when the state variable includes the current axial force, subtract the adjustment amount from the current axial force.

[0207] According to this configuration, unnecessary information that does not need to be transmitted to the vehicle driver is extracted from the disturbance torque, and the extracted unnecessary road information is removed from the current axial force. By using this current axial force, it is possible to obtain a reaction torque command value with reduced unnecessary information.

[0208] 15. A steering control device according to a fifteenth aspect is based on the steering control device according to the tenth aspect. The reaction torque command value is calculated by subtracting an axial force acting on the steered shaft from an assist torque. The assist torque is a torque in the same direction as the operation direction of the operator and is calculated based on the operation state of the operator. The axial force is calculated based on the steered state of the steered wheels. The first processing unit is configured to execute at least one of first signal processing that determines the adjustment amount by extracting, from the disturbance torque, frequency components that are important for the steering feel, and second signal processing that determines the adjustment amount by extracting, from the disturbance torque, frequency components that are unnecessary for the steering feel. The second processing unit is configured to add the adjustment amount to the assist torque when the first signal processing is executed, and to subtract the adjustment amount from the assist torque when the second signal processing is executed.

[0209] With this configuration, it is possible to obtain at least one of an assist torque to which road information to be transmitted to the vehicle driver has been added and an assist torque from which unnecessary information that does not need to be transmitted to the vehicle driver has been removed. By calculating a reaction torque command value using this assist torque, it is possible to obtain at least one of a reaction torque command value to which road information to be transmitted to the vehicle driver has been added and a reaction torque command value from which unnecessary information that does not need to be transmitted to the vehicle driver has been removed.

[0210] 16. A steering control device according to a sixteenth aspect is based on the steering control device according to the tenth aspect. The reaction torque command value is calculated by subtracting an axial force acting on the steered shaft from an assist torque. The assist torque is a torque in the same direction as the operation direction of the operator and is calculated based on the operation state of the operator. The axial force is calculated based on the steered state of the steered wheels. The first processing unit is configured to execute at least one of first signal processing that determines the adjustment amount by extracting, from the disturbance torque, frequency components that are important for the steering feel, and second signal processing that determines the adjustment amount by extracting, from the disturbance torque, frequency components that are unnecessary for the steering feel. The second processing unit is configured to add the adjustment amount to the axial force when the first signal processing is executed, and to subtract the adjustment amount from the axial force when the second signal processing is executed.

[0211] With this configuration, it is possible to obtain at least one of an axial force to which road information to be transmitted to the vehicle driver has been added and an axial force from which unnecessary information that does not need to be transmitted to the vehicle driver has been removed. By calculating a reaction torque command value using this axial force, it is possible to obtain at least one of a reaction torque command value to which road information to be transmitted to the vehicle driver has been added and a reaction torque command value from which unnecessary information that does not need to be transmitted to the vehicle driver has been removed.

Claims

1. A steering control device that controls a steering device having a motor that generates torque applied to an operator of a vehicle, and is configured to control the motor based on a torque command value calculated according to an operation state of the operator, wherein a disturbance estimator is configured to calculate a disturbance torque that affects the steered wheels of the vehicle and is a torque other than the torque generated by the motor, using a model that simulates the steering device; a first processing unit is configured to generate an adjustment amount for adjusting the torque command value based on the disturbance torque calculated by the disturbance estimator; and a second processing unit is configured to reflect the adjustment amount generated by the first processing unit in a state variable that is the basis for calculating the torque command value.

2. The steering control device according to claim 1, wherein the operator and the steered wheels are connected so as to be able to transmit power, and the motor is a steering motor that generates an assist force applied to a steering shaft that steers the steered wheels.

3. The steering control device according to claim 2, wherein the state variable is an axial force acting on the steering shaft, and is an axial force calculated based on a steering state of the steered wheels.

4. The steering control device according to claim 3, wherein the axial force includes at least one of an angular axial force calculated based on a target rotation angle of a pinion shaft that rotates in conjunction with the steering shaft, and a current axial force calculated based on a value of a current of the steering motor.

5. The steering device according to claim 4, wherein when the state variable includes the angular axial force, the first processing unit is configured to obtain the adjustment amount by extracting a frequency component important for steering feel from the disturbance torque, and the second processing unit is configured to add the adjustment amount to the angular axial force.

6. The steering device according to claim 4, wherein when the state variable includes the current axial force, the first processing unit is configured to obtain the adjustment amount by extracting a frequency component unnecessary for steering feel from the disturbance torque, and the second processing unit is configured to subtract the adjustment amount from the current axial force.

7. The state variable is the target steering torque of the operator calculated based on the axial force acting on the steering shaft, the axial force is the angular axial force calculated based on the target rotation angle of the pinion shaft that rotates in conjunction with the steering shaft, the first processing unit is configured to obtain the adjustment amount by extracting a frequency component important for steering feel from the disturbance torque, and the second processing unit is configured to add the adjustment amount to the target steering torque. The steering control device according to claim 2.

8. The state variable is the target steering torque of the operator calculated based on the axial force acting on the steering shaft, the axial force is the current axial force calculated based on the value of the current of the steering motor, the first processing unit is configured to obtain the adjustment amount by extracting a frequency component unnecessary for steering feel from the disturbance torque, and the second processing unit is configured to subtract the adjustment amount from the target steering torque. The steering control device according to claim 2.

9. The state variable is an assist torque that is a torque in the same direction as the operation direction of the operator, calculated based on the operation state of the operator. The first processing unit is configured to execute at least one of first signal processing for obtaining the adjustment amount by extracting a frequency component important for steering feel from the disturbance torque and second signal processing for obtaining the adjustment amount by extracting a frequency component unnecessary for steering feel from the disturbance torque. The second processing unit is configured to add the adjustment amount to the assist torque when the first signal processing is executed, and subtract the adjustment amount from the assist torque when the second signal processing is executed. The steering control device according to claim 2.

10. The operator and the steering wheel are mechanically separated so that mechanical power transmission is impossible. The motor includes a reaction force motor that generates a steering reaction force applied to the operator, and a steering motor that generates a steering force applied to a steering shaft that steers the steering wheel. The steering control device includes a reaction force control unit configured to control the reaction force motor based on a reaction torque command value calculated according to an operation state of the operator, and a steering control unit configured to control the steering motor based on a steering torque command value calculated according to the operation state of the operator. The steering control unit has the disturbance estimator, and the disturbance torque calculated by the disturbance estimator is a torque that affects the steering wheel and is other than the torque generated by the steering motor. The reaction force control unit includes the first processing unit and the second processing unit. The first processing unit is configured to generate an adjustment amount for adjusting the reaction torque command value based on the disturbance torque calculated by the disturbance estimator. The second processing unit is configured to reflect the adjustment amount generated by the first processing unit in a state variable that is the basis for calculating the reaction torque command value. The steering control device according to claim 1.

11. The state variable is an axial force acting on the steering shaft and is an axial force calculated based on a steering state of the steering wheel. The steering control device according to claim 10.

12. The axial force includes at least one of an angular axial force calculated based on a target rotation angle of a pinion shaft that rotates in conjunction with the steering shaft, and a current axial force calculated based on a value of a current of the steering motor. The steering control device according to claim 11.

13. When the state variable includes the angular axial force, the first processing unit is configured to obtain the adjustment amount by extracting a frequency component important for steering feel from the disturbance torque. When the state variable includes the angular axial force, the second processing unit is configured to add the adjustment amount to the angular axial force. The steering device according to claim 12.

14. When the state variable includes the current axial force, the first processing unit is configured to obtain the adjustment amount by extracting frequency components unnecessary for steering feel from the disturbance torque. The second processing unit is configured to subtract the adjustment amount from the current axial force when the state variable includes the current axial force. The steering apparatus according to claim 12.

15. The reaction torque command value is calculated by subtracting the axial force acting on the steering shaft from the assist torque. The assist torque is a torque in the same direction as the operation direction of the operator and is calculated based on the operation state of the operator. The axial force is calculated based on the steering state of the steering wheel. The first processing unit is configured to execute at least one of a first signal processing for obtaining the adjustment amount by extracting frequency components important for steering feel from the disturbance torque and a second signal processing for obtaining the adjustment amount by extracting frequency components unnecessary for steering feel from the disturbance torque. When the first signal processing is executed, the second processing unit is configured to add the adjustment amount to the assist torque, and when the second signal processing is executed, the second processing unit is configured to subtract the adjustment amount from the assist torque. The steering control apparatus according to claim 10.

16. The reaction torque command value is calculated by subtracting the axial force acting on the steering shaft from the assist torque. The assist torque is a torque in the same direction as the operation direction of the operator and is calculated based on the operation state of the operator. The axial force is calculated based on the steering state of the steering wheel. The first processing unit is configured to execute at least one of a first signal processing for obtaining the adjustment amount by extracting frequency components important for steering feel from the disturbance torque and a second signal processing for obtaining the adjustment amount by extracting frequency components unnecessary for steering feel from the disturbance torque. When the first signal processing is executed, the second processing unit is configured to add the adjustment amount to the axial force, and when the second signal processing is executed, the second processing unit is configured to subtract the adjustment amount from the axial force. The steering control apparatus according to claim 10.

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