Steering equipment

Abstract

The present invention discloses a steering device (10). The steering device (10) includes: a steering mechanism including a rotating shaft; a motor configured to apply a driving force to the steering mechanism; and a controller (50; 200) configured to control the motor based on a command value. The controller (50; 200) includes a first calculation circuit (81, 82, 83), a second calculation circuit (84) and a third calculation circuit (85). The first calculation circuit (81, 82, 83) is configured to calculate an axial force acting on the rotating shaft. The second calculation circuit (84) is configured to calculate a value indicating the degree of intervention of the main controller in the steering control, so that the value changes gradually with respect to time. The third calculation circuit (85) is configured to calculate a final axial force by reflecting the value indicating the degree of intervention into the axial force.

Description

Technical Field

[0001] The present invention relates to a steering device. Background Art

[0002] A so-called steer-by-wire type steering device is known in which power transmission between a steering wheel and a rotating wheel is mechanically isolated. The steering device includes a reaction motor, which is a source of generating a steering reaction force applied to a steering shaft, and a rotation motor, which is a source of generating a rotation force for rotating the rotating wheel. When the vehicle is running, a control device of the steering device performs reaction force control to generate a steering reaction force through the reaction motor, and performs rotation control to rotate the rotating wheel through the rotation motor.

[0003] In a steering device of the steer-by-wire type, since the power transmission between the steering wheel and the rotating wheel is mechanically isolated, it is difficult to transmit the road surface reaction force acting on the rotating wheel to the steering wheel. Therefore, it is difficult for the driver to feel the road surface condition through the steering wheel in the form of the steering reaction force on the driver's hand (feeling in the driver's hand).

[0004] Therefore, for example, the steering control device described in Japanese Patent Application Publication No. 2014-148299 calculates a feedforward axial force as an ideal rack axial force based on the steering angle, and calculates a feedback axial force as an estimated axial force based on the state quantity of the vehicle (lateral acceleration, rotational current, and yaw angular velocity). The steering control device calculates the final axial force by adding the values ​​obtained by multiplying the feedforward axial force and the feedback axial force by a predetermined distribution ratio, and controls the reaction motor based on the final axial force. Since the feedback axial force reflects the road surface state, the steering reaction force generated by the reaction motor also reflects the road surface state. Therefore, the driver can feel the road surface state in the form of a steering reaction force. Summary of the invention

[0005] The development of a driving assistance system that implements various driving assistance functions for improving the safety or convenience of a vehicle has been carried out. In recent years, the development of an automatic driving system that implements an automatic driving function by which the system performs driving instead of the driver has been actively carried out. The control device of the driving assistance system or the automatic driving system (hereinafter referred to as the "main control device") determines the optimal control method based on the state of the vehicle at that time, and commands the control device of the on-board system to perform separate control according to the determined control method. The steering control device controls the drive of the reaction motor and the turning motor based on the command value generated by the main control device.

[0006] In the case where a driving assistance system or an automatic driving system is equipped in a vehicle, there are the following concerns. For example, the steering reaction force generated by the reaction motor has an influence on the behavior of the steering wheel. Therefore, there is sometimes a difference in the demand for reaction force control performed by the steering control device between when the driver performs manual driving and when driving assistance or automatic driving is performed. For example, there may be a difference in the steering reaction force generated by the reaction motor between when the driver performs manual driving and when driving assistance or automatic driving is performed. Due to this difference, when the steering mode of the vehicle is switched between manual driving and driving assistance or between manual driving and automatic driving, there is a concern that the driver may feel unfamiliar due to, for example, a sudden change in the feeling of the driver's hands through the steering wheel.

[0007] In the case where a driving assist function or an automatic driving function is equipped in an electric power steering device (EPS) in which the torque of a motor is applied as an assist force to a steering mechanism of a vehicle, there are the same problems as those in the steering control device of a steer-by-wire type steering device.

[0008] The present invention reduces the driver's unfamiliarity when switching from automatic steering control to manual steering control.

[0009] One aspect of the present invention is a steering device. The steering device includes: a steering mechanism including a rotating shaft, through which a rotating wheel is rotated; a motor configured to apply a driving force to the steering mechanism; and a controller configured to control the motor based on a command value calculated according to a steering state. The controller includes a first calculation circuit, a second calculation circuit, and a third calculation circuit. The first calculation circuit is configured to calculate an axial force acting on the rotating shaft to be reflected in the command value according to the steering state. The second calculation circuit is configured to: calculate a value indicating the degree of intervention of the main controller in the steering control by performing a gradual change process on the value of the distribution command generated when the main controller installed on the vehicle intervenes in the steering control, so that the value gradually changes with respect to time. The third calculation circuit is configured to calculate the final axial force to be reflected in the command value by reflecting the value indicating the degree of intervention calculated by the second calculation circuit in the axial force calculated by the first calculation circuit.

[0010] There may be a difference in the demand for the driving force generated by the motor between when the main controller intervenes in the steering control and when the main controller does not intervene in the steering control. Therefore, when switching is performed between the state in which the main controller intervenes in the steering control and the state in which the main controller does not intervene in the steering control, there is a concern that the driver may feel unfamiliar due to a sudden change in the feeling of the driver's hands through the steering wheel, for example.

[0011] In this regard, using the above configuration, for example, when the main controller intervenes in the steering control, a value indicating the degree to which the main controller intervenes in the steering control is calculated by performing a gradient process on the assigned command by the second calculation circuit so that the value changes gradually with respect to time. Then, the gradually changing value indicating the degree of intervention is reflected in the axial force calculated by the first calculation circuit by the third calculation circuit, thereby calculating the final axial force to be reflected in the command value. Therefore, the final axial force gradually changes according to the gradually changing value indicating the degree of intervention. That is, the rapid change of the final axial force is suppressed, and further, the rapid change of the command value reflecting the final axial force is suppressed. Therefore, the rapid change of the driving force applied to the steering mechanism is suppressed, and therefore the driver is less likely to feel unfamiliar due to the change in the driving force applied to the steering mechanism.

[0012] In the steering device, the second calculation circuit may be configured to calculate an automatic driving rate as a value indicating a degree of intervention of the main controller in the steering control. The third calculation circuit may be configured to calculate a final axial force to be reflected in the command value by reflecting the automatic driving rate or a gain corresponding to the automatic driving rate in the axial force calculated by the first calculation circuit.

[0013] In the steering device, the controller may include a fourth calculation circuit, a fifth calculation circuit, a sixth calculation circuit, and a seventh calculation circuit. The fourth calculation circuit may be configured to calculate the target rotation angle of the shaft rotated according to the operation of the steering wheel based on the steering state and the final axial force calculated by the third calculation circuit. The fifth calculation circuit is configured to calculate the first distribution ratio of the main command value generated when the main controller intervenes in the steering control and the second distribution ratio for the target rotation angle calculated by the fourth calculation circuit by performing a gradual change process on the value of the distribution command, so that the first distribution ratio and the second distribution ratio gradually change with respect to time. The sixth calculation circuit is configured to use the value obtained from the first distribution ratio and the main command value and the value obtained from the second distribution ratio and the target rotation angle calculated by the fourth calculation circuit to calculate the final target rotation angle of the shaft. The seventh calculation circuit is configured to calculate the command value component to be reflected in the command value by feedback control so that the actual rotation angle of the shaft is consistent with the final target rotation angle of the shaft calculated by the sixth calculation circuit.

[0014] With the above configuration, for example, when the main controller intervenes in the steering control, the rapid change of the first distribution ratio and the second distribution ratio is suppressed by performing a gradual change process on the distribution command by the fifth calculation circuit. Therefore, the rapid change of the final target rotation angle used in the sixth calculation circuit is suppressed, and the rapid change of the driving force applied to the steering mechanism is further suppressed. That is, the driving force applied to the steering mechanism changes gradually. Therefore, the driver is less likely to feel unfamiliar due to the change of the driving force applied to the steering mechanism.

[0015] In the steering device, the steering mechanism may include a steering shaft that rotates together with the operation of the steering wheel, and the power transmission between the steering wheel and the rotating shaft is isolated. The motor may be a reaction motor that generates a steering reaction force as a driving force applied to the steering shaft, and the steering reaction force is a torque in the opposite direction of the steering direction.

[0016] In the steering device, the steering mechanism may include a shaft that rotates together with the operation of the steering wheel and that serves as a power transmission path between the steering wheel and the rotating shaft. The motor may be an auxiliary motor that generates a steering assist force as a driving force applied to the shaft or the rotating shaft, the steering assist force being a torque in the same direction as the steering direction.

[0017] By utilizing the steering device of the present invention, the unfamiliar feeling of the driver when switching from automatic steering control to manual steering control can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0019] Figure 1 is a configuration diagram of a steering device of a steer-by-wire type equipped with a first embodiment of a steering control device;

[0020] Figure 2 is a control block diagram of a first embodiment of a steering control device;

[0021] Figure 3 is a control block diagram of a steering reaction force command value calculation unit in the first embodiment;

[0022] Figure 4 is a control block diagram of the axial force calculation unit in the first embodiment;

[0023] Figure 5 is a control block diagram of an axial force calculation unit in a second embodiment of a steering control device;

[0024] Figure 6 is a control block diagram of an arrangement processing unit in a third embodiment of a steering control device;

[0025] Figure 7 is a control block diagram of an arrangement processing unit in a fourth embodiment of a steering control device;

[0026] Figure 8 is a front view showing the movement change of the steering wheel in the fifth embodiment of the steering control device; and

[0027] Fig. 9It is a control block diagram of a sixth embodiment of a steering control device provided in an electric power steering apparatus. DETAILED DESCRIPTION

[0028] A first embodiment in which the steering control device is applied to a steering apparatus of the steer-by-wire type will be described below.

[0029] like Figure 1 As shown, the steering device 10 of the vehicle includes a steering shaft 12 connected to a steering wheel 11. The steering shaft 12 constitutes a steering mechanism. In addition, the steering device 10 includes a Figure 1 The left and right rotating wheels 16 are connected to both ends of the rotating shaft 14 through the pull rods 15. The rotation angle θ of the rotating wheel 16 is w The change is made by the linear movement of the rotating shaft 14 .

[0030] The steering device 10 includes a reaction motor 31, a speed reducer 32, a rotation angle sensor 33, and a torque sensor 34 as a configuration for generating a steering reaction force. Incidentally, the steering reaction force is a force (torque) acting in a direction opposite to the direction in which the driver operates the steering wheel 11. By applying the steering reaction force to the steering wheel 11, a moderate feeling can be generated in the driver's hand.

[0031] The reaction motor 31 is a generation source of the steering reaction force. As the reaction motor 31, for example, a brushless motor having three phases (U, V, and W) is adopted. The reaction motor 31 (more precisely, the rotating shaft of the reaction motor 31) is connected to the steering shaft 12 through a speed reducer 32. The torque of the reaction motor 31 is applied to the steering shaft 12 as the steering reaction force.

[0032] The rotation angle sensor 33 is provided on the reaction motor 31. The rotation angle sensor 33 detects the rotation angle θ of the reaction motor 31. a The rotation angle θ of the reaction motor 31 a Used to calculate the steering angle (steering angle) θ s The reaction motor 31 and the steering shaft 12 are interlocked with each other through the speed reducer 32. Therefore, the rotation angle θ of the reaction motor 31 a The rotation angle of the steering shaft 12 is related to the steering angle θ which is the rotation angle of the steering wheel 11. s Therefore, the rotation angle θ of the reaction motor 31 can be used to determine the rotation angle θ of the reaction motor 31. a To determine the steering angle θ s .

[0033] The torque sensor 34 detects the steering torque T applied to the steering shaft 12 by the rotation operation of the steering wheel 11. hThe torque sensor 34 is provided at a portion located on the steering shaft 12 and closer to the steering wheel 11 than the speed reducer 32 .

[0034] The steering apparatus 10 includes a turning motor 41 , a speed reducer 42 , and a rotation angle sensor 43 as a configuration for generating a turning force, which is a power for turning the turning wheel 16 .

[0035] The rotary motor 41 is a source of rotational force. As the rotary motor 41, for example, a brushless motor having three phases is used. The rotary motor 41 (more precisely, the rotating shaft of the rotary motor 41) is connected to the pinion shaft 44 through the reducer 42. The pinion teeth 44a of the pinion shaft 44 mesh with the rack teeth 14b of the rotary shaft 14. The torque of the rotary motor 41 is applied to the rotary shaft 14 as a rotational force through the pinion shaft 44. As the rotary motor 41 rotates, the rotary shaft 14 moves in the vehicle width direction (the left-right direction in the figure).

[0036] The rotation angle sensor 43 is provided on the rotary motor 41. The rotation angle sensor 43 detects the rotation angle θ of the rotary motor 41. b . Incidentally, the steering device 10 includes a pinion shaft 13. The pinion shaft 13 is arranged to intersect with the rotating shaft 14. The pinion teeth 13a of the pinion shaft 13 are meshed with the rack teeth 14a of the rotating shaft 14. The reason for providing the pinion shaft 13 is that the pinion shaft 13 supports the rotating shaft 14 in the housing (not shown) together with the pinion shaft 44. That is, by a supporting mechanism (not shown) provided in the steering device 10, the rotating shaft 14 is supported so that the rotating shaft 14 can move along the axial direction of the rotating shaft 14 and is pressed toward the pinion shafts 13, 44. Therefore, the rotating shaft 14 is supported in the housing. However, another supporting mechanism may be provided that supports the rotating shaft 14 in the housing without using the pinion shaft 13.

[0037] The steering apparatus 10 includes a control device 50. The control device 50 controls the reaction motor 31 and the rotary motor 41 based on the detection results of various sensors. As a sensor, in addition to the above-mentioned rotation angle sensor 33, torque sensor 34, and rotation angle sensor 43, there is a vehicle speed sensor 501. The vehicle speed sensor 501 is provided in the vehicle, and detects a vehicle speed V as a vehicle travel speed.

[0038] The control device 50 performs reaction force control by driving the reaction motor 31 to generate a reaction force corresponding to the steering torque T h The control device 50 is based on the steering torque T h and vehicle speed V to calculate the target steering reaction force, and based on the calculated target steering reaction force, steering torque T hThe control device 50 calculates the target steering angle of the steering wheel 11 by using the steering angle θ and the vehicle speed V. s The feedback control is used to calculate the steering angle correction amount so that the actual steering angle θ s The target steering angle is followed, and the control device 50 calculates a steering reaction force command value by adding the calculated steering angle correction amount to the target steering reaction force. The control device 50 supplies the reaction motor 31 with a current required to generate a steering reaction force corresponding to the steering reaction force command value.

[0039] The control device 50 performs rotation control by driving control of the rotation motor 41 to rotate the rotation wheel 16 according to the rotation state. The control device 50 performs rotation control based on the rotation angle θ of the rotation motor 41 detected by the rotation angle sensor 43. b To calculate the pinion angle θ p , the pinion angle θ p is the actual rotation angle of the pinion shaft 44. The pinion angle θ p is the rotation angle θ of the rotating wheel 16 w The control device 50 uses the above-mentioned target steering angle to calculate the target pinion angle. Then, the control device 50 determines the target pinion angle and the actual pinion angle θ p and controls the power supply to the rotary motor 41 so that the deviation is eliminated.

[0040] Vehicles are sometimes equipped with a driving assistance system that assists the driver's driving operation to achieve safe and better driving, or an automatic driving system that implements an automatic driving function, through which the automatic driving function system performs driving instead of the driver. In this case, in the vehicle, cooperative control between the control device 50 and the control device of another vehicle-mounted system is performed. Cooperative control is a technology in which the control devices of multiple vehicle-mounted systems cooperate with each other to control the actions of the vehicle. For example, the vehicle is equipped with a main control device 500, which controls the various vehicle-mounted control devices of the vehicle-mounted system as a whole. The main control device 500 determines the optimal control method based on the state of the vehicle at that time, and commands each control device to perform separate control according to the determined control method.

[0041] The main control device 500 intervenes in the steering control through the control device 50. The main control device 500 switches the driving assistance control function or the automatic driving control function of the main control device 500 between an on state (enabled) and an off state (disabled) by operating a switch not shown provided at a driver's seat or the like.

[0042] For example, the main control device 500 calculates the additional angle command value as the command value S *, which is used to make the vehicle travel in the target lane. The additional angle command value is the target value of the steering angle (the angle to be added to the current steering angle) required to make the vehicle travel along the lane according to the vehicle's current driving state. The control device 50 uses the command value S calculated by the main control device 500. * To control the reaction motor 31 and the rotation motor 41.

[0043] In addition, the main control device 500 generates a flag as an allocation command S for the control device 50 r . The flag is information indicating whether the driving assistance control function or the automatic driving control function is in an on state or an off state. When the driving assistance control function or the automatic driving control function is in an on state, the main control device 500 sets the value of the flag to "1". When the driving assistance control function or the automatic driving control function is in an off state, the main control device 500 sets the value of the flag to "0".

[0044] Next, the control device 50 will be described in detail. Figure 2 As shown, the control device 50 includes a reaction force control unit 50a that performs reaction force control and a rotation control unit 50b that performs rotation control.

[0045] The reaction force control unit 50 a includes a steering angle calculation unit 51 , a steering reaction force command value calculation unit 52 , and an energization control unit 53 .

[0046] The steering angle calculation unit 51 calculates the steering angle based on the rotation angle θ of the reaction motor 31 detected by the rotation angle sensor 33. a To calculate the steering angle θ of the steering wheel 11 s The steering reaction force command value calculation unit 52 calculates the steering reaction force command value based on the steering torque Th, the vehicle speed V and the steering angle θ. s To calculate the steering reaction force command value T * When the absolute value of the steering torque Th is large and the vehicle speed V is low, the steering reaction force command value calculation unit 52 calculates the steering reaction force command value T having a large absolute value. * Incidentally, the steering reaction force command value calculation unit 52 calculates the steering reaction force command value T * The target steering angle θ of the steering wheel 11 is calculated in the process * The steering reaction force command value calculation unit 52 will be described in detail later.

[0047] The energization control unit 53 provides the reaction motor 31 with a steering reaction force command value T * Specifically, the energization control unit 53 determines the steering reaction force command value T based on the steering reaction force command value T. *The current command value for the reaction motor 31 is calculated. In addition, the energization control unit 53 detects the actual current value I generated in the power supply path to the reaction motor 31 through the current sensor 54 provided on the power supply path. a Current value I a is the value of the actual current supplied to the reaction motor 31. Then, the energization control unit 53 determines the current command value and the actual current value I a and controls the power supply to the reaction motor 31 so that the deviation is eliminated (the current value I a Thus, the reaction motor 31 generates a steering reaction force command value T * The corresponding torque can produce a moderate feeling corresponding to the reaction force of the road surface in the driver's hands.

[0048] The steering control unit 50 b includes a pinion angle calculation unit 61 , a pinion angle feedback control unit 62 , and an energization control unit 63 .

[0049] The pinion angle calculation unit 61 calculates the rotation angle θ of the rotary motor 41 based on the rotation angle θ detected by the rotation angle sensor 43 . b To calculate the pinion angle θ p , the pinion angle θ p is the actual rotation angle of the pinion shaft 44. The rotary motor 41 and the pinion shaft 44 are interlocked with each other through the speed reducer 42. Therefore, at the rotation angle θ of the rotary motor 41 b and the pinion angle θ p By using this correlation, the rotation angle θ of the rotary motor 41 can be b Determine the pinion angle θ p In addition, the pinion shaft 44 meshes with the rotating shaft 14. Therefore, at the pinion angle θ p There is a correlation between the angle θ and the movement amount of the rotating shaft 14. p is the rotation angle θ of the rotating wheel 16 w The value of .

[0050] The pinion angle feedback control unit 62 receives the target steering angle θ calculated by the steering reaction force command value calculation unit 52. * As the target pinion angle θ p * In addition, the pinion angle feedback control unit 62 receives the actual pinion angle θ calculated by the pinion angle calculation unit 61. p The pinion angle feedback control unit 62 uses the pinion angle θ p Feedback control (PID control) is used to calculate the pinion angle command value T p* , so that the actual pinion angle θ p Follow the target pinion angle θ p * (In this embodiment, the target pinion angle θ p * Equal to the target steering angle θ * ).

[0051] The energization control unit 63 provides the rotary motor 41 with the pinion angle command value T p * Specifically, the energization control unit 63 controls the power supply based on the pinion angle command value T p * The current command value for the rotary motor 41 is calculated. In addition, the energization control unit 63 detects the actual current value I generated in the power supply path to the rotary motor 41 through the current sensor 64 provided on the power supply path. b Current value I b is the value of the actual current supplied to the rotary motor 41. Then, the energization control unit 63 determines the current command value and the actual current value I b and controls the power supply to the rotary motor 41 so that the deviation is eliminated (the current value I b Thus, the rotary motor 41 rotates with the pinion angle command value T p * The corresponding angle.

[0052] Next, the steering reaction force command value calculation unit 52 will be described in detail. Figure 3 As shown, the steering reaction force command value calculation unit 52 includes an adder 70, a target steering torque calculation unit 71, a torque feedback control unit 72, an axial force calculation unit 73, a target steering angle calculation unit 74, a steering angle feedback control unit 75 and an arrangement processing unit 76.

[0053] The adder 70 adds the steering torque T detected by the torque sensor 34 h and the first steering reaction force command value T1 calculated by the torque feedback control unit 72 * Add together to calculate the input torque T in * As the torque applied to the steering shaft 12 .

[0054] The target steering torque calculation unit 71 calculates the target steering torque based on the input torque T calculated by the adder 70. in * To calculate the target steering torque T h * Target steering torque T h* is the steering torque T to be applied to the steering wheel 11 h When the input torque T in * When the absolute value of is larger, the target steering torque calculation unit 71 calculates the target steering torque T having a larger absolute value. h * .

[0055] The torque feedback control unit 72 receives the steering torque T detected by the torque sensor 34. h and the target steering torque T calculated by the target steering torque calculation unit 71 h * The torque feedback control unit 72 uses the steering torque T h The first steering reaction force command value T1 is calculated by feedback control (PID control) * , so that the steering torque T detected by the torque sensor 34 h Following target steering torque T h * .

[0056] The axial force calculation unit 73 receives the target steering angle θ calculated by the target steering angle calculation unit 74. * As the target pinion angle θ p * In addition, the axial force calculation unit 73 receives the current value I of the rotary motor 41 detected by the current sensor 64. b and the vehicle speed V detected by the vehicle speed sensor 501. The axial force calculation unit 73 calculates the target pinion angle θ based on the target pinion angle θ. p * , the current value I of the rotating motor 41 b and the vehicle speed V to calculate the axial force F acting on the rotating shaft 14 through the rotating wheel 16 ax The axial force calculation unit 73 will be described in detail later.

[0057] The target steering angle calculation unit 74 receives the steering torque T detected by the torque sensor 34. h , the first steering reaction force command value T1 calculated by the torque feedback control unit 72 * , the axial force F calculated by the axial force calculation unit 73 ax and the vehicle speed V detected by the vehicle speed sensor 501. The target steering angle calculation unit 74 calculates the target steering angle based on the received steering torque T h , first steering reaction force command value T1 * , axial force F ax and the vehicle speed V to calculate the target steering angle θ of the steering wheel 11 * . The details are as follows.

[0058] The target steering angle calculation unit 74 calculates the target steering angle by calculating the input torque T in * Subtract the axial force F from ax The torque conversion value (steering reaction force corresponding to the axial force) obtained by converting the torque into the final input torque T for the steering wheel 11 is determined. in * , input torque T in * is the first steering reaction force command value T1 * and steering torque T h The target steering angle calculation unit 74 calculates the target steering angle from the final input torque T based on the ideal model represented by the following expression (A): in * Calculate the target steering angle θ * (Target steering angle). For the ideal model, under the premise that the steering wheel 11 and the rotating wheel 16 are mechanically connected to the steering device, according to the input torque T in * The steering angle (steering angle) of the steering wheel 11 corresponding to the ideal rotation angle is modeled in advance through experiments or the like.

[0059] T in * =Jθ * ″+Cθ * ′+Kθ * ...(A)

[0060] Among them, "J" is the inertia coefficient corresponding to the inertia moment of the steering wheel 11 and the steering shaft 12, "C" is the viscosity coefficient (friction coefficient) corresponding to the friction between the rotating shaft 14 and the housing, and "K" is the spring modulus when each of the steering wheel 11 and the steering shaft 12 is regarded as a spring. The viscosity coefficient C and the inertia coefficient J are values ​​that depend on the vehicle speed V. In addition, "θ * "" is the target steering angle θ * The second-order time differential value of "θ * '" is the target steering angle θ * The first-order time differential of .

[0061] Incidentally, in the case where the additional angle command value is calculated as the command value S by executing the driving assist control or the automatic driving control by the main control device 500, * In the case of * is added to the target steering angle θ calculated by the target steering angle calculation unit 74. * . Add the command value S * The final target steering angle θ *is supplied to each of the axial force calculation unit 73 and the steering angle feedback control unit 75 .

[0062] The steering angle feedback control unit 75 receives the steering angle θ calculated by the steering angle calculation unit 51. s and the target steering angle θ calculated by the target steering angle calculation unit 74 * The steering angle feedback control unit 75 uses the steering angle θ s The feedback control is used to calculate the second steering reaction force command value T2 * , so that the actual steering angle θ calculated by the steering angle calculation unit 51 s Following the target steering angle θ * .

[0063] The arrangement processing unit 76 receives the first steering reaction force command value T1 calculated by the torque feedback control unit 72. * , the second steering reaction force command value T2 calculated by the steering angle feedback control unit 75 * and the distribution command S calculated by the main control device 500 r The arrangement processing unit 76 allocates the command S r , based on the first steering reaction force command value T1 * and the second steering reaction force command value T2 * To calculate the steering reaction force command value T * As the arrangement processing unit 76, one of three configurations (a1) to (a3) ​​described below is adopted.

[0064] (a1) The arrangement processing unit 76 arranges the r The value of the sign is the first steering reaction force command value T1 * and the second steering reaction force command value T2 * One of them is set as the steering reaction force command value T * When used as the allocation command S r When the flag value of is "0", the arrangement processing unit 76 sets the first steering reaction force command value T1 * Set to the final steering reaction force command value T * When used as the allocation command S r When the flag value of is "1" (more precisely, when the flag value is not "0"), the arrangement processing unit 76 sets the second steering reaction force command value T2 * Set to the steering reaction force command value T * .

[0065] (a2) Arrangement processing unit 76 by adjusting the second steering reaction force command value T2 *The first steering reaction force command value T1 * Add to calculate the steering reaction force command value T * , or based on the assignment command S r The value of the sign is the first steering reaction force command value T1 * Set unchanged to the steering reaction force command value T * When used as the allocation command S r When the flag value of is "0", the arrangement processing unit 76 sets the first steering reaction force command value T1 * Set unchanged to the steering reaction force command value T * When used as the allocation command S r When the flag value of is "1", the arrangement processing unit 76 sets the first steering reaction force command value T1 * and the second steering reaction force command value T2 * Add to calculate the steering reaction force command value T * .

[0066] (a3) First, the arrangement processing unit 76 performs the allocation according to the allocation command S r The value of the sign is used to calculate the first steering reaction force command value T1 * The first distribution ratio and the second steering reaction force command value T2 * The first distribution ratio and the second distribution ratio may be set in consideration of state variables reflecting vehicle behavior, road surface conditions, or steering conditions. Next, the arrangement processing unit 76 calculates the steering reaction force command value T by adding the following values: * :By setting the first steering reaction force command value T1 * The value obtained by multiplying the first distribution ratio and the second steering reaction force command value T2 * Multiply the value obtained by the second distribution ratio.

[0067] Next, the axial force calculation unit 73 will be described in detail. Figure 4 As shown, the axial force calculation unit 73 includes an ideal axial force calculation unit 81 , an estimated axial force calculation unit 82 , a distribution calculation unit 83 , a gradual change processing unit 84 , and a multiplier 85 .

[0068] The ideal axial force calculation unit 81 calculates the target pinion angle θ based on the target pinion angle θ. p * The ideal axial force F1 is calculated by the vehicle speed V and the ideal axial force F1 is an ideal value of the axial force acting on the rotating shaft 14 by the rotating wheel 16. The ideal axial force calculation unit 81 calculates the ideal axial force F1 using an ideal axial force map stored in a storage device (not shown) of the control device 50. p *(or by changing the target pinion angle θ p * As the absolute value of the target rotation angle (obtained by multiplying the predetermined conversion factor) increases and the vehicle speed V is lower, the ideal axial force F1 is set to a value having a larger absolute value. The vehicle speed V does not always need to be considered.

[0069] The estimated axial force calculation unit 82 calculates the estimated axial force based on the current value I of the rotary motor 41. b The estimated axial force F2 acting on the rotating shaft 14 is calculated. The disturbance corresponding to the road surface state (friction resistance of the road surface) acts on the rotating wheel 16, thereby generating the target pinion angle θ p * and the actual pinion angle θ p The difference between the current value I of the rotating motor 41 b That is, the current value I of the rotating motor 41 is changed. b The actual road surface reaction force acting on the rotating wheel 16 is reflected. Therefore, the current value I of the rotating motor 41 can be used to b The axial force reflecting the influence of the road surface state is calculated by changing the current value I of the rotary motor 41 to b The estimated axial force F2 is determined by multiplying by a gain, which is a coefficient depending on the vehicle speed V.

[0070] The distribution calculation unit 83 sets a distribution ratio (gain) for the ideal axial force F1 and a distribution ratio for the estimated axial force F2, respectively. The distribution calculation unit 83 calculates the mixed axial force F3 by adding the values ​​obtained by multiplying the ideal axial force F1 and the estimated axial force F2 by the individually set distribution ratios, respectively. The distribution ratio is set according to various state variables reflecting vehicle behavior, road surface conditions, or steering conditions.

[0071] The gradient processing unit 84 receives the distribution command S generated by the main control device 500. r The gradient processing unit 84 performs the following operations by assigning the command S r The flag value (in the embodiment, "0" or "1") performs a gradual change process (a process for gradual change) with respect to time to calculate the automatic driving rate DR a For example, when the driving assistance control function or the automatic driving control function is switched from the off state to the on state, the main control device 500 will be used as the distribution command S r The flag value is switched from "0" to "1". At this time, the gradual change processing unit 84 changes the automatic driving rate DR to "0.1", for example. a The value of gradually changes from "0" to "1".

[0072] By the way, the autonomous driving rate DR ais a value indicating the degree to which the system participates in the driving of the vehicle (the degree to which the main control device 500 in this embodiment intervenes in the steering control). As the driving assistance system becomes more complex or is enhanced due to the improvement of the technical level, the degree to which the system participates in the driving increases. For example, when the automatic driving rate DR a When the automatic driving rate DR is 100%, the system completely replaces the driver to perform driving. a When it is 0%, the driver performs all driving environment recognition, risk judgment and driving operations (steering, acceleration, deceleration, etc.) of the vehicle.

[0073] As the gradation processing unit 84, one of the two configurations (b1), (b2) described below is adopted.

[0074] (b1) The gradual change processing unit 84 has a so-called time-dependent change amount protection function for protecting the amount of change per unit time as the distribution command S. r The amount of change in the value of the flag is limited to a predetermined limit value. The gradual change processing unit 84 may change the limit value according to the steering speed, the target steering speed, the steering torque, or the steering torque differential value.

[0075] (b2) A low-pass filter is used as the gradual change processing unit 84. The low-pass filter can change the cutoff frequency according to the steering speed, the target steering speed, the steering torque, or the steering torque differential value.

[0076] The multiplier 85 multiplies the mixed axial force F3 calculated by the distribution calculation unit 83 by the automatic driving rate DR calculated by the gradual change processing unit 84. a Multiply to calculate the axial force F ax Therefore, with the first embodiment, the following operations and effects can be obtained.

[0077] There may be a difference in the demand for the steering reaction force (driving force) generated by the reaction motor 31 between when the main control device 500 intervenes in the steering control and when the main control device 500 does not intervene in the steering control. In this case, when the driving assist control function or the automatic driving control function is switched between the on state and the off state, there is a concern that the driver may feel unfamiliar due to a sudden change in the feeling of the driver's hands through the steering wheel, for example.

[0078] In this regard, the axial force calculation unit 73 in the present embodiment is provided with a gradual change processing unit 84, which changes the distribution command S generated by the main control device 500. r Then, the axial force calculation unit 73 calculates the mixed axial force F3 calculated by the distribution calculation unit 83 by the automatic driving rate DR. a To calculate the final axial force F ax , autonomous driving rate DRa is calculated by the gradient processing unit 84 through gradient processing.

[0079] Therefore, when the driving assistance control function or the automatic driving control function is switched between the on state and the off state, the allocation ratio S is adjusted by the gradual change processing unit 84. r Perform gradual change processing to suppress the final axial force F ax That is, suppress the rapid change of the target steering angle θ * (Target pinion angle θ p * ) changes rapidly, the second steering reaction force command value T2 * The rapid change of the steering reaction force command value T * The driver is less likely to feel unfamiliar due to the change in the steering reaction force. In addition, the switching between manual driving and driving assistance or the switching between manual driving and automatic driving can be smoothly performed.

[0080] Next, a second embodiment of the steering control device will be described. Basically, the second embodiment has the same Figures 1 to 4 The second embodiment is different from the first embodiment in the configuration of the axial force calculation unit 73 .

[0081] like Figure 5 As shown in FIG. 1 , the axial force calculation unit 73 includes, in addition to the ideal axial force calculation unit 81, the estimated axial force calculation unit 82, the distribution calculation unit 83, the gradient processing unit 84, and the multiplier 85, a gain calculation unit 86. The gain calculation unit 86 is provided on the calculation path between the gradient processing unit 84 and the multiplier 85. The gain calculation unit 86 is based on the automatic driving rate DR calculated by the gradient processing unit 84. a , calculates the gain G for the hybrid axial force F3 calculated by the distribution calculation unit 83 f Gain G f The combined axial force F3 and the final axial force F ax For example, when the automatic driving rate DR a When the value of is large, the gain calculation unit 86 calculates the gain G with a smaller value. f The multiplier 85 multiplies the mixed axial force F3 calculated by the distribution calculation unit 83 by the gain G calculated by the gain calculation unit 86. f Multiply to calculate the final axial force F ax .

[0082] Therefore, according to the second embodiment, in addition to the effects of the first embodiment, the following effects can be obtained. ax The hybrid shaft force F3 is multiplied by the automatic driving rate DR a The corresponding gain G f By adjusting the gain G f For the autonomous driving rate DR a The changing characteristics of the axial force F ax In addition, a more appropriate axial force F can be calculated ax .

[0083] Next, a third embodiment of the steering control device will be described. Basically, the third embodiment has the same Figures 1 to 4 The third embodiment has the same configuration as the first embodiment shown, but is different from the first embodiment in the configuration of the steering reaction force command value calculation unit 52. The third embodiment can be applied to the second embodiment.

[0084] like Figure 3 As shown by the double-dashed line in FIG. 5 , in the steering reaction force command value calculation unit 52, a layout processing unit 90 is provided on the calculation path between the target steering angle calculation unit 74 and the steering angle feedback control unit 75. The layout processing unit 90 receives the target steering angle θ calculated by the target steering angle calculation unit 74. * , the command value S calculated by the main control device 500 * (additional angle command value in this embodiment) and the distribution command S r The arrangement processing unit 90 allocates the command S r Based on the target steering angle θ * and command value S * Calculate the final target steering angle θ * .

[0085] like Figure 6 As shown, the arrangement processing unit 90 includes a gradient processing unit 91, a multiplier 92, a subtractor 93, a multiplier 94, and an adder 95. The gradient processing unit 91 receives the allocation command S generated by the main control device 500. r The gradient processing unit 91 assigns the command S r The distribution ratio DR1 is calculated by performing a gradual change process with respect to time based on the value of the flag (in this embodiment, "0" or "1"). The distribution ratio DR1 is used for the command value S calculated by the main control device 500. * In addition, the allocation ratio DR1 can be regarded as an automatic driving rate indicating the degree to which the system participates in the driving of the vehicle (the degree to which the main control device 500 in the embodiment intervenes in the steering control).

[0086] The multiplier 92 converts the command value S * The command value S1 corresponding to the distribution ratio DR1 is calculated by multiplying the distribution ratio DR1 by * . The subtractor 93 calculates the distribution ratio DR2 by subtracting the value of the distribution ratio DR1 from "1", which is a fixed value stored in the storage device of the control device 50. Therefore, when the value of the distribution ratio DR1 is "1 (100%)", the value of the distribution ratio DR2 is "0 (0%)". When the value of the distribution ratio DR1 is "0", the value of the distribution ratio DR2 is "1". The distribution ratio DR2 is used for the target steering angle θ calculated by the target steering angle calculation unit 74. * distribution ratio.

[0087] The multiplier 94 is configured to multiply the target steering angle θ calculated by the target steering angle calculation unit 74 by * The target steering angle θ1 corresponding to the distribution ratio DR2 is calculated by multiplying the distribution ratio DR2 by * The adder 95 adds the command value S1 corresponding to the distribution ratio DR1 and calculated by the multiplier 92. * The target steering angle θ1 calculated by the multiplier 94 corresponding to the distribution ratio DR2 is * The final target steering angle θ is calculated by adding the values ​​of * .

[0088] Therefore, with the third embodiment, in addition to the effects in the first embodiment, the following effects can be obtained. The arrangement processing unit 90 calculates the final target steering angle θ for the steering angle feedback control unit 75 by adding the following values: * :Set the command value S * multiplied by the distribution command S from the main control device 500 r The value obtained by the distribution ratio DR1 is equal to the target steering angle θ calculated by the target steering angle calculation unit 74. * The value obtained by multiplying the distribution ratio DR2 based on the distribution ratio DR1. In addition, the arrangement processing unit 90 is provided with a gradual change processing unit 91, which processes the distribution command S from the main control device 500. r Performs a gradient process with respect to time.

[0089] Therefore, when the driving assistance control function or the automatic driving control function is switched between the on state and the off state, the gradient processing unit 91 allocates the command S r The gradual change process is performed to suppress the rapid change of the two distribution ratios DR1 and DR2. Therefore, the final target steering angle θ used in the steering angle feedback control unit 75 is suppressed. *The rapid change of the steering reaction force applied to the steering wheel 11 is further suppressed. Therefore, the steering reaction force applied to the steering wheel 11 changes gradually, so that the driver is less likely to feel strange due to the change of the steering reaction force. In addition, the switching between manual driving and driving assistance or the switching between manual driving and automatic driving can be smoothly performed.

[0090] Next, a fourth embodiment of the steering control device will be described. Basically, the fourth embodiment has the same Figures 1 to 4 The fourth embodiment has the same configuration as the first embodiment shown, but is different from the first embodiment in the configuration of the steering reaction force command value calculation unit 52. The fourth embodiment can be applied to the second embodiment and the third embodiment.

[0091] like Figure 2 As shown by the double-dashed line in FIG. 1 , the rotation control unit 50b is provided with a placement processing unit 100. The placement processing unit 100 is provided on a calculation path between the steering reaction force command value calculation unit 52 of the reaction force control unit 50a and the pinion angle feedback control unit 62 of the rotation control unit 50b. The placement processing unit 100 receives the information generated by Figure 3 The target steering angle θ calculated by the target steering angle calculation unit 74 of the steering reaction force command value calculation unit 52 is shown as * As the target pinion angle θ p * In addition, the placement processing unit 100 receives the allocation command S r and the command value S calculated by the main control device 500 * (Additional angle command value in this embodiment) The arrangement processing unit 100 arranges the target pinion angle θ according to the distribution command Sr. p * and command value S * Calculate the final target steering angle θ * .

[0092] like Figure 7 As shown, the arrangement processing unit 100 includes a gradient processing unit 101, a multiplier 102, a subtractor 103, a multiplier 104, and an adder 105. The gradient processing unit 101 receives the allocation command S generated by the main control device 500. r The gradient processing unit 101 assigns the command S r The distribution ratio DR is calculated by performing a gradual change process with respect to time by using the flag value (“0” or “1” in the embodiment). 11 . Allocation ratio DR 11 is the command value S calculated by the main control device 500 * In addition, the distribution ratio DR11 The automatic driving rate can be regarded as indicating the degree to which the system is involved in the driving of the vehicle (in this embodiment, the degree to which the main control device 500 intervenes in the steering control).

[0093] The multiplier 102 converts the command value S * Multiply by the distribution ratio DR 11 To calculate the distribution ratio DR 11 The command value S 11 * The subtractor 103 subtracts the distribution ratio DR from "1". 11 The value of the distribution ratio DR is calculated 22 , "1" is a fixed value stored in the storage device of the control device 50. Therefore, when the distribution ratio DR 11 When the value is "1 (100%)", the allocation ratio DR 22 The value of is "0 (0%)". 11 When the value is "0", the allocation ratio DR 22 The value of is "1".

[0094] The multiplier 104 is obtained by calculating the target steering angle by the target steering angle calculation unit 74 (see Figure 3 ) Calculate the target pinion angle θ p * (In this embodiment, it is equal to the target steering angle θ * ) multiplied by the distribution ratio DR 22 , to calculate the distribution ratio DR 22 The target pinion angle θ p1 * .

[0095] The adder 105 is configured to divide the distribution ratio DR by 11 The command value S calculated by the multiplier 102 is 11 * and corresponds to the distribution ratio DR 22 The target pinion angle θ calculated by the multiplier 104 is p1 * The final target pinion angle θ is calculated by adding the pinion angle feedback control unit 62. p * .

[0096] Therefore, according to the fourth embodiment, in addition to the effects of the first embodiment, the following effects can be obtained. The arrangement processing unit 100 arranges the arrangement processing unit 100 by assigning the allocation command S based on the allocation command S from the main control device 500. r The distribution ratio DR 11 Multiply by the command value S * The resulting value will be based on the allocation ratio DR 11The distribution ratio DR 22 multiplied by the target pinion angle θ from the target steering angle calculation unit 74 p * The obtained values ​​are added to calculate the final target pinion angle θ used in the pinion angle feedback control unit 62. p * In addition, the arrangement processing unit 100 is provided with a gradual change processing unit 101, which processes the distribution command S from the main control device 500. r Performs a gradient process with respect to time.

[0097] Therefore, when the driving assistance control function or the automatic driving control function is switched between the on state and the off state, the gradient processing unit 101 allocates the command S r Perform gradient processing to suppress the two distribution ratios DR 11 ,DR 22 Therefore, the final target pinion angle θ used in the pinion angle feedback control unit 62 is suppressed. p * The rapid change of the rotation angle θ w Therefore, the rotation angle θ of the rotating wheel 16 w gradually changes, so that the driver is less likely to turn the angle θ w In addition, the switch between manual driving and driving assistance or the switch between manual driving and automatic driving can be performed smoothly.

[0098] Next, a fifth embodiment of the steering control device will be described. The fifth embodiment differs from the third embodiment in that Figure 6 The operation of the gradient processing unit 91 is shown.

[0099] The steering wheel 11 is arranged so that it can be moved between an operation position and a predetermined storage position suitable for the operation of the steering wheel 11 by the action of a drive mechanism not shown. The action of the drive mechanism is controlled by the control device 50.

[0100] When recognizing that the automatic driving control function has been switched from the off state to the on state by the operation of a switch provided at the driver's seat or the like, the control device 50 withdraws the steering wheel 11 from the operating position to the storage position through the drive mechanism. Conversely, when recognizing that the automatic driving control function has been switched from the on state to the off state by the operation of a switch provided at the driver's seat or the like, the control device 50 returns the steering wheel 11 from the storage position to the operating position through the drive mechanism.

[0101] When the automatic driving control is executed, the control device 50 executes the rotation control to rotate the rotating wheel 16, and does not execute the reaction force control to generate the steering reaction force by the reaction motor 31. That is, when the automatic driving is executed, the rotating wheel 16 is automatically rotated, but the steering wheel 11 does not operate.

[0102] When the distribution command S from the main control device 500 is r When recognizing that the automatic driving control function has been switched from the off state to the on state, the arrangement processing unit 90 forcibly sets "0" as the target steering angle θ provided to the steering angle feedback control unit 75. * The arrangement processing unit 90, for example, calculates the final target steering angle θ calculated by the adder 95 by * The value "0" is multiplied as a coefficient to set "0" as the target steering angle θ provided to the steering angle feedback control unit 75. * The value of .

[0103] The arrangement processing unit 90 sends the axial force calculation unit 73 (see Figure 3 ) and the pinion angle feedback control unit 62 (see Figure 2 ) provides the final target steering angle θ calculated by adder 95 unchanged * As the target pinion angle θ p * Therefore, the wheel 16 is rotated according to the target pinion angle θ p * Perform a rotation motion.

[0104] When the distribution command S from the main control device 500 is r When recognizing that the automatic driving control function has been switched from the on state to the off state, the processing unit 90 calculates the target steering angle θ calculated by the adder 95 * is provided to the steering angle feedback control unit 75. Naturally, the target steering angle θ calculated by the adder 95 is * The target pinion angle θ is taken as p * It is also provided to the axial force calculation unit 73 and the pinion angle feedback control unit 62 .

[0105] Since the storage structure for the steering wheel 11 is adopted, the following configuration is used as the gradient processing unit 91 of the arrangement processing unit 90. Figure 6 As shown by the double-dashed line in FIG. 1 , the gradient processing unit 91 includes a counter 91 a. r When recognizing that the automatic driving control function has been switched from the on state to the off state, the gradual change processing unit 91 drives the counter 91a.r When recognizing that the automatic driving control function has been switched from the on state to the off state, the gradual change processing unit 91 executes the allocation command S r The execution state of the gradual change process of the flag value is switched to wait for the assignment command S r The execution of the gradual change process of the flag value starts in the waiting state.

[0106] When the time measured by the counter 91a reaches the predetermined waiting time, the gradient processing unit 91 starts to process the distribution command S as r The gradient processing is performed based on the value of the flag of the storage position. The waiting time is set based on the time required for the steering wheel 11 to move from the storage position to the operation position. When the gradient processing unit 91 remains in the waiting state, as the allocation command S r In this embodiment, although when the automatic driving control function is switched from the on state to the off state, as the allocation command S r The flag value of is switched from "1 (100%)" to "0 (0%)", but since the gradient processing unit 91 remains in the waiting state, the allocation command S r The value of the flag is maintained at "1". After the waiting state of the gradual change processing unit 91 is canceled because the waiting time has passed since the automatic driving control function is switched from the on state to the off state, the gradual change processing unit 91 responds to the allocation command S r The flag value performs a gradient process so that as the assignment command S r The value of the flag gradually changes from "1" to "0".

[0107] Next, the operation of the fifth embodiment will be described. Figure 8 As shown in “During Automatic Driving” in FIG. 1 , when the automatic driving control is executed, the steering wheel 11 is maintained in the following state: the steering wheel 11 is withdrawn to a predetermined storage position in the vehicle cabin.

[0108] like Figure 8 As shown in "Automatic Driving Cancellation (Initial)" in FIG. 1 , when the automatic driving control is canceled by operating a switch provided at the driver's seat or the like, the steering wheel 11 begins to return from the storage position to the operating position in response to the cancellation. Note that the steering wheel 11 does not rotate at this time.

[0109] The reason is as follows. That is, since the gradient processing unit 91 is in a waiting state, the allocation command S r The flag value remains at "1". Therefore, the command value S * The value of the distribution ratio DR1 is "1 (100%)", and is used for the target steering angle θ calculated by the target steering angle calculation unit 74. *The value of the distribution ratio DR2 is "0". In addition, since the automatic driving control function has been switched from the on state to the off state, the command value S calculated by the main control device 500 * The value of is "0". Incidentally, when the command value S * When the main control device 500 is not configured to calculate, when the automatic driving control function is in the off state, the multiplier 92 of the processing unit 90 is arranged to convert the command value S * The value of is processed as "0". Therefore, while the gradual change processing unit 91 remains in the waiting state, the final target steering angle θ calculated by the adder 95 * The value of is "0".

[0110] like Figure 8 As shown in the "Automatic Driving → Manual Driving Transition Period" in FIG. 1 , at the time when the time measured by the counter 91a reaches the waiting time, the steering wheel 11 is returned to the operating position. In addition, since the waiting state of the gradual change processing unit 91 is canceled when the time measured by the counter 91a reaches the waiting time, the gradual change processing unit 91 starts to process the assigned command S r The flag value performs the gradient processing. With the assignment command S r The flag value gradually changes from "1" to "0" for the command value S * The value of the distribution ratio DR1 gradually decreases from "1" to "0", and the target steering angle θ calculated by the target steering angle calculation unit 74 is * The distribution ratio DR2 of the steering wheel 11 gradually increases from "0" to "1". s From the target steering angle θ during autonomous driving * (=0) gradually approaches the target steering angle θ during manual driving * (In this embodiment, the target steering angle θ calculated by the target steering angle calculation unit 74) * ).

[0111] Then, if Figure 8 The "manual driving transition is completed" is shown in the command value S * The value of the distribution ratio DR1 reaches "0", and the target steering angle θ calculated by the target steering angle calculation unit 74 is * The distribution ratio DR2 reaches a value of "1". Thus, the transition from automatic driving control to manual driving control is completed. At the moment of completion of the transition, the steering angle θ of the steering wheel 11 s The target steering angle θ during manual driving * (In this embodiment, the target steering angle θ calculated by the target steering angle calculation unit 74) * ) are consistent.

[0112] Therefore, with the fifth embodiment, the following effects can be obtained. In the case of adopting a configuration in which the steering wheel 11 is withdrawn from the operating position to the storage position when the automatic driving control function is executed, when the automatic driving control function has been switched from the on state to the off state, the final target steering angle θ is set to the same value as the target steering angle θ in the period before the steering wheel 11 is returned from the storage position to the operating position. * Maintained at “0”. Therefore, even in the case where the steering wheel 11 is not operated, the steering wheel 11 is restricted from rotating unnecessarily.

[0113] In addition, when the automatic driving control function has been switched from the on state to the off state, after the steering wheel 11 completes the return from the storage position to the operating position, the gradient processing unit 91 starts to process the automatic driving control function as the assigned command S. r The flag value performs the gradient processing. With the assignment command S r The value of the flag gradually changes from "1" to "0" for the target steering angle θ calculated by the target steering angle calculation unit 74. * The distribution ratio DR2 of the steering wheel 11 gradually changes from "0" to "1". s gradually approaches the target steering angle θ calculated by the target steering angle calculation unit 74 * . Therefore, switching from automatic driving control to manual driving control can be performed smoothly.

[0114] Next, a sixth embodiment will be described in which the steering control device is implemented as a control device of an electric power steering apparatus (EPS). The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description of the components is omitted.

[0115] In EPS, Figure 1 The steering wheel 11 and the rotating wheel 16 are shown to be mechanically coupled to each other. That is, the steering shaft 12, the pinion shaft 13, and the rotating shaft 14 serve as a power transmission path between the steering wheel 11 and the rotating wheel 16. The rotating shaft 14 moves linearly due to the rotation operation of the steering wheel 11, so that the rotation angle θ of the rotating wheel 16 is w In addition, the EPS includes an auxiliary motor which is arranged at Figure 1 The reaction motor 31 is shown at the same position as one of the rotary motors 41. The assist motor generates a steering assist force (assist force).

[0116] like Fig. 9 As shown, the control device 201 of the EPS 200 performs assist control to generate a torque corresponding to the steering torque T by controlling the energization of the assist motor 202. hThe control device 201 is based on the steering torque T detected by the torque sensor 34. h , the vehicle speed V detected by the vehicle speed sensor 501 and the rotation angle θ detected by the rotation angle sensor 203 provided on the assist motor 202 m To control the power supply to the assist motor 202.

[0117] The control device 201 includes a pinion angle calculation unit 211, an assist command value calculation unit 212, and an energization control unit 213. The pinion angle calculation unit 211 receives a rotation angle θ of the assist motor 202. m , and based on the received rotation angle θ m Calculate the pinion angle θ p , pinion angle θ p is the rotation angle of the pinion shaft 13. The assist command value calculation unit 212 calculates the assist command value based on the steering torque T h and vehicle speed V to calculate the assist command value T as * . Auxiliary command value T as * is a command value indicating an assist torque which is a rotational force to be generated by the assist motor 202. The energization control unit 213 provides the assist motor 202 with a torque corresponding to the assist command value T as * The current sensor 214 is provided on the power supply path to the auxiliary motor 202. The current sensor 214 detects the current value I m As the actual current value supplied to the assist motor 202.

[0118] Next, the configuration of the assist command value calculation unit 212 will be described in detail. The assist command value calculation unit 212 includes an assist torque calculation unit 221, an axial force calculation unit 222, a target pinion angle calculation unit 223, a pinion angle feedback control unit (pinion angle F / B control unit) 224, and an arrangement processing unit 225.

[0119] The assist torque calculation unit 221 calculates the steering torque T h Calculate the first assist torque T as1 * The assist torque calculation unit 221 includes an adder 231, a target steering torque calculation unit 232, and a torque feedback control unit 233. The adder 231 calculates the steering torque T detected by the torque sensor 34. h and the first assist torque T calculated by the torque feedback control unit 233 as1 * Add together to calculate the input torque T in *The target steering torque calculation unit 232 calculates the target steering torque T based on the input torque T calculated by the adder 231. in * To calculate the target steering torque T h * When the input torque T in * When the absolute value of is larger, the target steering torque calculation unit 232 calculates the target steering torque T having a larger absolute value. h * The torque feedback control unit 233 receives the steering torque T detected by the torque sensor 34. h and the target steering torque T calculated by the target steering torque calculation unit 232 h * The torque feedback control unit 233 uses the steering torque T h The first assist torque T is calculated by feedback control (PID control) as1 * , so that the steering torque T detected by the torque sensor 34 h Following target steering torque T h * .

[0120] Incidentally, the following configuration may be adopted as the assist torque calculation unit 221. That is, the assist torque calculation unit 221 uses the steering torque T specified according to the vehicle speed V. h and the first assist torque T as1 * The three-dimensional diagram of the relationship between the steering torque T h The first assist torque T is calculated by feedback control as1 * When the steering torque T h When the absolute value of is large and the vehicle speed V is low, the assist torque calculation unit 221 calculates the first assist torque T as1 * Set the absolute value of to a larger value.

[0121] The axial force calculation unit 222 has Figure 4 The axial force calculation unit 222 has the same function as the axial force calculation unit 73 in the first embodiment shown in the figure. The axial force calculation unit 222 receives the current value I of the assist motor 202 detected by the current sensor 214. m , the target pinion angle θ calculated by the target pinion angle calculation unit 223 p * The axial force calculation unit 222 calculates the vehicle speed V detected by the vehicle speed sensor 501 based on the current value I of the assist motor 202. m 、Target pinion angle θ p* and the vehicle speed V to calculate the axial force F acting on the rotating shaft 14 ax In addition, the axial force calculation unit 222 includes a gradient processing unit 222a. The gradient processing unit 222a has Figure 4 The gradient processing unit 222a performs gradient processing (processing for gradual change) with respect to time for the value of a flag ("0" or "1" in the embodiment) of the distribution command Sr.

[0122] The target pinion angle calculation unit 223 has Figure 3 The target steering angle calculation unit 223 has the same function as the target steering angle calculation unit 74 in the first embodiment shown in the figure. The target pinion angle calculation unit 223 uses the first assist torque T calculated by the assist torque calculation unit 221. as1 * , the steering torque T detected by the torque sensor 34 h and the axial force F calculated by the axial force calculation unit 222 ax The target pinion angle θ is calculated based on the ideal model represented by expression (A) p * .

[0123] The pinion angle feedback control unit 224 has Figure 3 The pinion angle feedback control unit 224 receives the target pinion angle θ calculated by the target pinion angle calculation unit 223. p * and the actual pinion angle θ calculated by the pinion angle calculation unit 211 p The pinion angle feedback control unit 224 performs PID control (proportional control, integral control or differential control) as the pinion angle θ p The feedback control makes the actual pinion angle θ p Follow the target pinion angle θ p * That is, the pinion angle feedback control unit 224 determines the target pinion angle θ p * and the actual pinion angle θ p The deviation between the two, and calculate the second assist torque T as2 * so that the deviation is eliminated.

[0124] The arrangement processing unit 225 has Figure 3The arrangement processing unit 225 has the same function as the arrangement processing unit 76 in the first embodiment shown. The arrangement processing unit 225 receives the first assist torque T calculated by the torque feedback control unit 233. as1 * , the second assist torque T calculated by the pinion angle feedback control unit 224 as2 * and the distribution command S calculated by the main control device 500 r The arrangement processing unit 225 allocates the command S r Based on the first assist torque T as1 * and the second assist torque T as2 * Calculate the auxiliary command value T as * .

[0125] The energization control unit 213 is based on the assist command value T as * The current command value for assisting the motor 202 is calculated. In addition, the energization control unit 213 receives the current value I detected by the current sensor 214. m Then, the power-on control unit 213 determines the current command value and the actual current value I m The power supply to the assist motor 202 is controlled so that the deviation is eliminated. As a result, the assist motor 202 generates a power corresponding to the assist command value T as * That is, steering assist corresponding to the steering state is performed.

[0126] In the control device 201, the following configuration may be provided instead of the gradual change processing unit 222a of the axial force calculation unit 222, or in addition to the gradual change processing unit 222a. Fig. 9 As shown by the double-dotted line in FIG. 2 , the control device 201 may include a layout processing unit 241. The layout processing unit 241 has Figure 6 The arrangement processing unit 241 has the same functions as the arrangement processing unit 90 in the third embodiment shown in the figure. The arrangement processing unit 241 receives the target pinion angle θ calculated by the target pinion angle calculation unit 223. p * , the command value S calculated by the main control device 500 * And the assignment command S r The arrangement processing unit 241 allocates the command S r Based on the target pinion angle θ p * and command value S * Calculate the final target pinion angle θ p * .

[0127] Therefore, with the sixth embodiment, the following effects can be obtained. When the driving assistance control function or the automatic driving control function is switched between the on state and the off state, the allocation ratio S is adjusted by the gradual change processing unit 222a. r Perform a gradual change to suppress the final axial force F ax That is, suppress the target pinion angle θ p * The rapid change of the second auxiliary torque T as2 * Rapid changes in auxiliary command value T as * The driver is less likely to feel unfamiliar due to the change in the assist force. In addition, the switching between manual driving and driving assistance or the switching between manual driving and automatic driving can be smoothly performed.

[0128] In the case where the control device 201 includes the arrangement processing unit 241, the following effects can also be obtained. That is, when the driving assistance control function or the automatic driving control function is switched between the on state and the off state, the allocation ratio S is allocated by the arrangement processing unit 241. r Gradient processing is performed to suppress the use of the command value S * The rapid change of the distribution ratio and the target pinion angle θ calculated by the target pinion angle calculation unit 223 p * Therefore, the final target pinion angle θ used in the pinion angle feedback control unit 224 is suppressed. p * The rapid change of the assist force applied to the steering wheel 11 is further suppressed. Therefore, the assist force applied to the steering wheel 11 changes gradually, whereby the driver is less likely to feel strange due to the change of the assist force. In addition, the switching between manual driving and driving assistance or the switching between manual driving and automatic driving can be smoothly performed.

[0129] The above-described embodiment may be implemented while being modified as follows. In the first to fifth embodiments, a clutch may be provided in the steering device 10. In this case, as Figure 1As shown by the double-dotted line in FIG, the steering shaft 12 and the pinion shaft 13 are connected by a clutch 21. An electromagnetic clutch that connects and disconnects power by electrically connecting and disconnecting an excitation coil is used as the clutch 21. The control device 50 performs a connect-disconnect control to switch the clutch 21 between connection and disconnection. When the clutch 21 is disconnected, the power transmission between the steering wheel 11 and the rotating wheel 16 is mechanically disconnected. When the clutch 21 is connected, the power transmission between the steering wheel 11 and the rotating wheel 16 is mechanically connected.

[0130] In the first to fifth embodiments, in addition to or instead of the estimated axial force F2, at least one of the axial forces (c1) to (c4) described below may be used as the estimated axial force calculated by the axial force calculation unit 73. The same is true for the axial force calculation unit 222 in the sixth embodiment.

[0131] (c1) An estimated axial force calculated based on at least one of the lateral acceleration and the yaw rate

[0132] (c2) Axial force detected by the axial force sensor

[0133] (c3) Tire force detected by a tire force sensor, or tire axle force calculated based on the tire force

[0134] (c4) An estimated axial force obtained by adding values ​​obtained by multiplying the estimated axial force F2, the mixed axial force F3, and the estimated axial force F4 by individually set predetermined distribution ratios.

[0135] In the first to sixth embodiments, one of the forces (c1) to (c4), the estimated axial force F2, and the ideal axial force F1 may be used as the final axial force F ax .

[0136] In the first to sixth embodiments, the main control device 500 may calculate an additional torque command value instead of the additional angle command value as the command value S * In this case, the steering reaction force command value calculation unit 52 in the first to fifth embodiments and the assist command value calculation unit 212 in the sixth embodiment may convert the additional torque command value into the additional angle command value, and may use the converted additional angle command value. Each of the steering reaction force command value calculation unit 52 and the assist command value calculation unit 212 is provided with a conversion unit that converts the additional torque command value into the additional angle command value.

[0137] In the first to fifth embodiments, it is possible to adopt a method not including Figure 3The arrangement processing unit 76 is configured as the steering reaction force command value calculation unit 52. In this case, the second steering reaction force command value T2 calculated by the steering angle feedback control unit 75 is * Used as the steering reaction force command value T * In addition, in the sixth embodiment, it is possible to adopt a method that does not include Fig. 9 The arrangement processing unit 225 is configured as the assist command value calculation unit 212. In this case, the second assist torque T calculated by the pinion angle feedback control unit 224 is as2 * Used as auxiliary command value T as * .

[0138] In the first embodiment, the target pinion angle θ may be used as the state variable for calculating the ideal axial force F1 or the estimated axial force F2 instead of the mixed axial force F3 calculated by the distribution calculation unit 83. p * The target steering angle θ * Or the current value I of the rotating motor 41 b , to execute the automatic driving rate DR calculated by the gradient processing unit 84 of the axial force calculation unit 73 a For the gain G calculated by the gain calculation unit 86 in the second embodiment, f The above description can be similarly applied to the axial force calculation unit 222 in the sixth embodiment.

Claims

1. A steering device (10), characterized in that include: A steering mechanism including a rotating shaft, through which the rotating wheel is rotated; a motor configured to apply a driving force to the steering mechanism; as well as A controller (50; 200) configured to control the motor based on a command value calculated according to a steering state, wherein The controller (50; 200) comprises a first calculation circuit (81, 82, 83), a second calculation circuit (84), a third calculation circuit (85), a fourth calculation circuit (74; 223), a fifth calculation circuit (91, 93), a sixth calculation circuit (92, 94, 95) and a seventh calculation circuit (75, 224), The first calculation circuit (81, 82, 83) is configured to calculate an axial force acting on the rotating shaft to be reflected in the command value according to the steering state, The second calculation circuit (84) is configured to calculate a value indicating a degree of intervention of the main controller with respect to the steering control by performing a gradual change process on a value of an allocation command generated when the main controller mounted on the vehicle intervenes in the steering control so that the value gradually changes with respect to time, The third calculation circuit (85) is configured to calculate a final axial force to be reflected in the command value by reflecting the value indicating the degree of intervention calculated by the second calculation circuit (84) in the axial force calculated by the first calculation circuit (81, 82, 83), The fourth calculation circuit (74; 223) is configured to calculate a target rotation angle of the shaft rotated according to the operation of the steering wheel based on the steering state and the final axial force calculated by the third calculation circuit (85), The fifth calculation circuit (91, 93) is configured to calculate a first distribution ratio for a main command value generated when the main controller intervenes in steering control and a second distribution ratio for a target rotation angle calculated by the fourth calculation circuit (74; 223) by performing a gradual change process on the value of the distribution command so that the first distribution ratio and the second distribution ratio gradually change with respect to time, a sixth calculation circuit (92, 94, 95) configured to calculate a final target rotation angle of the shaft using a value obtained from the first distribution ratio and the main command value and a value obtained from the second distribution ratio and the target rotation angle calculated by the fourth calculation circuit (74; 223); and The seventh calculation circuit (75, 224) is configured to calculate a command value component to be reflected in the command value by feedback control so that the actual rotation angle of the shaft coincides with the final target rotation angle of the shaft calculated by the sixth calculation circuit (92, 94, 95).

2. The steering device (10) according to claim 1, characterized in that: The second calculation circuit (84) is configured to calculate an automatic driving rate as a value indicating a degree of intervention of the main controller on steering control; and The third calculation circuit (85) is configured to calculate a final axial force to be reflected in the command value by reflecting the automatic driving rate or a gain corresponding to the automatic driving rate in the axial force calculated by the first calculation circuit (81, 82, 83).

3. The steering device (10) according to claim 1 or 2, characterized in that: The steering mechanism comprises a steering shaft (12) that rotates together with the operation of a steering wheel (11), and the power transmission between the steering wheel and the rotating shaft is isolated; as well as The motor is a reaction motor (31) that generates a steering reaction force as a driving force applied to the steering shaft (12), the steering reaction force being a torque in a direction opposite to a steering direction.

4. The steering device (10) according to claim 1 or 2, characterized in that: The steering mechanism includes a shaft which rotates together with the operation of the steering wheel (11) and which serves as a power transmission path between the steering wheel (11) and the rotating shaft; as well as The motor is an assist motor (202) that generates a steering assist force as a driving force applied to the shaft or the rotating shaft, the steering assist force being a torque in the same direction as a steering direction.

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