Steering control device and steering control method

Abstract

This invention relates to a steering control device and a steering control method. The steering torque control process (M26) includes a process of calculating an operating amount for controlling the steering torque to the target steering torque using a proportional element (M50) and a derivative element (M60) corresponding to the difference between the steering torque and the target steering torque. At least one of the proportional element and the derivative element is provided with an amplification phase controller (M54, M66), which is a controller that amplifies the advance of the phase of the derivative element relative to the phase of the proportional element.

Description

Technical Field

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

[0002] For example, Patent Document 1 describes a control device that controls the torque applied to the steering wheel, i.e. the steering torque, to a target value through feedback control.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2014-223832

[0004] When implementing the aforementioned torque feedback control, balancing stability and responsiveness becomes a challenge. Summary of the Invention

[0005] In one embodiment of the present invention, a steering control device is provided, which operates a motor mechanically connected to an operating component operated by a driver for steering the vehicle. The steering control device is configured to perform steering torque control processing and operation processing. The steering torque control processing includes a process for calculating an operating amount for controlling the steering torque to the target steering torque using a proportional element and a derivative element corresponding to the difference between the steering torque and a target steering torque. The operation processing includes a process for operating a drive circuit of the motor to control the torque of the motor according to the operating amount. The steering torque is a torque input to the operating component. At least one of the proportional element and the derivative element is provided with an amplification phase controller, which is configured to amplify the advance of the phase of the derivative element relative to the phase of the proportional element.

[0006] In other embodiments of the present invention, a steering control method is provided for operating a motor mechanically connected to an operating component operated by a driver for steering a vehicle. The steering control method includes a step of performing a steering torque control process and a step of performing an operation process. The steering torque control process includes a process of calculating an operating amount for controlling the steering torque to the target steering torque using a proportional element and a derivative element corresponding to the difference between the steering torque and a target steering torque. The operation process is a process of operating a drive circuit of the motor to control the torque of the motor according to the operating amount. The steering torque is a torque input to the operating component. The steering torque control process includes a process of increasing the advance of the phase of the derivative element relative to the phase of the proportional element by providing an amplification phase controller for at least one of the proportional element and the derivative element. Attached Figure Description

[0007] Figure 1 This is a diagram showing the structure of the steering control system according to the first embodiment.

[0008] Figure 2 This is a block diagram illustrating the processing performed by the control device in the first embodiment.

[0009] Figure 3 This is a block diagram showing the details of a portion of the processing performed by the control device in the first embodiment.

[0010] Figure 4 This is a diagram showing the characteristics of the filter according to the first embodiment.

[0011] Figure 5A as well as Figure 5B This is a timing diagram representing the response characteristics of the first embodiment.

[0012] Figure 6A as well as Figure 6B This is a diagram illustrating the effects of the first embodiment.

[0013] Figure 7A This is a timing diagram illustrating the characteristics of the first embodiment. Figure 7B This is a timing diagram representing the characteristics of the comparative example.

[0014] Figure 8A as well as Figure 8B This is a diagram illustrating the effects of the first embodiment.

[0015] Figure 9A This is a timing diagram illustrating the characteristics of the first embodiment. Figure 9B This is a timing diagram representing the characteristics of the comparative example.

[0016] Figure 10 This is a block diagram showing the details of a portion of the processing performed by the control device in the second embodiment.

[0017] Figure 11A as well as Figure 11B This is a diagram illustrating the effects of the second embodiment.

[0018] Figure 12 This is a block diagram showing the details of a portion of the processing performed by the control device in the third embodiment.

[0019] Figure 13A as well as Figure 13B This is a diagram illustrating the effects of the third embodiment.

[0020] Figure 14 This is a block diagram showing the details of a portion of the processing performed by the control device in the fourth embodiment.

[0021] Figure 15 This is a block diagram showing the details of a portion of the processing performed by the control device in the fifth embodiment. Detailed Implementation

[0022] <First Implementation>

[0023] The first embodiment of the steering control device will now be described with reference to the accompanying drawings.

[0024] "Prerequisite Structure"

[0025] like Figure 1 As shown, the vehicle's steering system 10 includes a reaction force actuator Ar and a steering actuator At. The steering system 10 of this embodiment has a structure that mechanically cuts off the power transmission path between the steering wheel 12 and the steering wheel 44. That is, the steering system 10 includes an electric steering device.

[0026] The steering wheel 12 is connected to the steering shaft 14. The reaction force actuator Ar is an actuator used to apply steering reaction force to the steering wheel 12. Steering reaction force refers to a force acting in the opposite direction to the driver's operation of the steering wheel 12. By applying steering reaction force to the steering wheel 12, a suitable responsive feel can be provided to the driver. The reaction force actuator Ar includes a reduction mechanism 16, a reaction force motor 20, and a reaction force inverter 22.

[0027] The reaction motor 20 is a three-phase brushless motor. The rotating shaft of the reaction motor 20 is connected to the steering shaft 14 via the reduction gear 16. The reaction inverter 22 is a power conversion circuit that converts the voltage of the DC voltage source, i.e., the voltage of the battery 24, into AC voltage and applies it to the reaction motor 20.

[0028] On the other hand, the steering shaft 40 along Figure 1 The steering axle 40 extends in the left-right direction, i.e., the width direction of the vehicle. Left and right steering wheels 44 are connected to both ends of the steering axle 40 via steering tie rods 42. The steering angle of the steering wheels 44 is changed by linear movement of the steering axle 40.

[0029] The steering actuator AT includes a reduction gear 56, a steering motor 60, and a steering inverter 62. The steering motor 60 is a three-phase brushless motor. The rotation shaft of the steering motor 60 is connected to a pinion shaft 52 via the reduction gear 56. The pinion teeth of the pinion shaft 52 mesh with the rack teeth 54 of the steering shaft 40. The pinion shaft 52 and the steering shaft 40 with rack teeth 54 constitute a rack and pinion mechanism. The torque of the steering motor 60 is applied to the steering shaft 40 as a steering force via the pinion shaft 52. According to the rotation of the steering motor 60, the steering shaft 40 moves along... Figure 1It moves in the left and right directions, that is, in the width direction of the vehicle.

[0030] The steering system 10 has a control device 70.

[0031] The control device 70 controls the steering mechanism. Specifically, the control device 70 controls the steering wheel 12 of the steering mechanism. To control the amount of force applied to the controlled object, i.e., the steering reaction force, the control device 70 operates the reaction force actuator Ar. Figure 1 The control unit 70 records the operation signal MSs for the inverter 22 used for reaction force. Additionally, the control unit 70 controls the steering wheel 44 of the steering mechanism. To control the amount of the controlled object, i.e., the steering angle of the steering wheel 44, the control unit 70 operates the steering actuator At. The steering angle is the rotation angle of the tires. Figure 1 The document contains the operation signal MSt for the steering inverter 62.

[0032] To control the control quantity, control device 70 refers to the input torque to steering shaft 14, i.e., the steering torque Th, detected by torque sensor 80. Torque sensor 80 includes a torsion bar connected to steering shaft 14 and a sensing element that detects the torsion angle of the torsion bar. Additionally, control device 70 refers to the rotation angle θa of the rotating shaft of reaction motor 20 detected by rotation angle sensor 82. Furthermore, control device 70 refers to the currents iu1, iv1, and iw1 flowing in reaction motor 20. Currents iu1, iv1, and iw1 are quantified as the voltage drop across the shunt resistors at each pin of the reaction inverter 22. To control the control quantity, control device 70 refers to the rotation angle θb of the rotating shaft of steering motor 60 detected by rotation angle sensor 84. Additionally, control device 70 refers to the currents iu2, iv2, and iw2 flowing in steering motor 60. The currents iu2, iv2, and iw2 are quantified as the voltage drop across the shunt resistors at each pin of the steering inverter 62. Additionally, the control device 70 references the vehicle speed V detected by the vehicle speed sensor 86.

[0033] The control device 70 includes a PU 72, a storage device 74, and peripheral circuitry 76. The PU 72 is a software processing device such as a CPU, GPU, or TPU. The storage device 74 includes electrically erasable and rewritable non-volatile memory and a disk medium. A steering control program 74a is stored in the storage device 74. The peripheral circuitry 76 includes circuitry for generating clock signals that define internal actions, a power supply circuit, and a reset circuit. The control device 70 executes the steering control program 74a stored in the storage device 74 via the PU 72 to control the control quantities.

[0034] "control"

[0035] exist Figure 2 The diagram shows a portion of the process performed by the control device 70.

[0036] The steering angle calculation process M10 calculates the steering angle θh of the steering wheel 12 by taking the rotation angle θa as input. The steering angle calculation process M10 includes, for example, counting the number of rotations of the reaction force motor 20 from the position of the steering wheel 12 at the neutral steering position when the vehicle is moving forward, and converting the rotation angle θa into a cumulative angle covering a range exceeding 360°. The steering angle calculation process M10 includes calculating the steering angle θh by multiplying the converted cumulative angle by a conversion factor based on the rotational speed ratio of the reduction gear 16. Furthermore, the steering angle θh is positive, for example, when the angle is to the right of the neutral steering position, and negative when the angle is to the left.

[0037] The pinion angle calculation process M12 calculates the rotation angle of the pinion shaft 52, i.e., the pinion angle θp, using the rotation angle θb as input. The pinion angle calculation process M12 includes, for example, counting the number of rotations of the steering motor 60 from the neutral position of the rack when the vehicle is moving forward, and converting the rotation angle θb into a cumulative angle covering a range exceeding 360°. The pinion angle calculation process M12 includes calculating the actual rotation angle of the pinion shaft 52, i.e., the pinion angle θp, by multiplying the converted cumulative angle by a conversion factor based on the rotational speed ratio of the reduction mechanism 56. Furthermore, the pinion angle θp is positive, for example, when the angle is to the right of the rack neutral position, and negative when the angle is to the left. The steering motor 60 and the pinion shaft 52 are linked via the reduction mechanism 56. Therefore, there is a one-to-one correspondence between the cumulative value of the rotation angle θb of the steering motor 60 and the pinion angle θp. This correspondence allows us to calculate the pinion angle θp based on the rotation angle θb of the steering motor 60. Furthermore, the pinion shaft 52 meshes with the steering shaft 40. Therefore, there is also a one-to-one correspondence between the pinion angle θp and the amount of movement of the steering shaft 40. That is, the pinion angle θp reflects the steering angle of the steering wheel 44.

[0038] The target pinion angle calculation process M14 takes the steering angle θh and vehicle speed V as inputs and calculates the target pinion angle θp*. The target pinion angle θp* is the target value of the pinion angle θp corresponding to the steering wheel 12 operation performed by the driver. The target pinion angle calculation process M14 includes a process that sets the steering ratio to be variable based on the vehicle speed V. Therefore, the target pinion angle θp* output by the target pinion angle calculation process M14 is a different value depending on the vehicle speed V, even if it is the same as the input steering angle θh.

[0039] The pinion angle feedback processing M16 is used to control the pinion angle θp to the target pinion angle θp*, and to calculate the command value of the torque of the steering motor 60, i.e., the steering torque command value Tt*.

[0040] The steering operation processing M18 takes the steering torque command value Tt*, currents iu2, iv2, iw2, and rotation angle θb as inputs and outputs an operation signal MSt relative to the steering inverter 62. The steering operation processing M18 includes a process for calculating the current command value of the dq axis based on the steering torque command value Tt*. Furthermore, the steering operation processing M18 includes a process for calculating the current of the dq axis based on currents iu2, iv2, iw2, and rotation angle θb. Moreover, the steering operation processing M18 includes a process for calculating the operation signal MSt that should operate the steering inverter 62, using the dq axis current as the command value.

[0041] The axial force calculation process M19 includes a process that takes the steering torque command value Tt* as input and calculates the axial force Taf. Here, the axial force Taf is the axial force applied to the steering shaft 40.

[0042] The reference target torque calculation process M20 calculates the reference value, i.e., the reference target torque Thb*, of the target steering torque Th* that the driver should input to the steering shaft 14 via the steering wheel 12, based on the axial force Taf. The axial force Taf corresponds to the lateral force acting on the steering wheel 44, so the lateral force can be controlled through the axial force Taf. On the other hand, the torque that the driver should input to the steering shaft 14 via the steering wheel 12 is preferably determined based on the lateral force. Therefore, the reference target torque calculation process M20 calculates the reference target torque Thb* based on the lateral force controlled from the axial force Taf.

[0043] In detail, the reference target torque calculation process M20 is a process that variably sets the absolute value of the reference target torque Thb* based on the vehicle speed V, even when the absolute value of the axial force Taf is the same. This process can also be configured to calculate the absolute value of the reference target torque Thb* when the vehicle speed V is low as less than the absolute value of the reference target torque Thb* when the vehicle speed V is high. This can be achieved, for example, by performing a mapping table operation on the reference target torque Thb* by the PU72 while the mapping table data is pre-stored in the storage device 74. This mapping table data is data that takes the axial force Taf, or the lateral acceleration determined based on the axial force Taf, and the vehicle speed V as input variables, and the reference target torque Thb* as the output variable.

[0044] Furthermore, the mapping table data is a set of discrete values ​​of input variables and corresponding values ​​of output variables. Mapping table operations can be performed as follows: if the value of an input variable matches any one of the input variables in the mapping table data, the value of the corresponding output variable in the mapping table data is taken as the result. Alternatively, if the value of an input variable does not match any of the input variables in the mapping table data, the value obtained by interpolation of the multiple output variables contained in the mapping table data is taken as the result. Alternatively, mapping table operations can also be performed as follows: if the value of an input variable does not match any of the input variables in the mapping table data, the value of the output variable in the mapping table data corresponding to the nearest value among the multiple output variables contained in the mapping table data is taken as the result.

[0045] The hysteresis processing M22 calculates and outputs a hysteresis correction amount Thys based on the steering angle θh, which corrects for the reference target torque Thb*. Specifically, the hysteresis processing M22 includes a process that identifies when the steering wheel 12 is turned and when it is returned to its original position based on changes in the steering angle θh, and calculates the hysteresis correction amount Thys. Specifically, the hysteresis processing M22 includes a process that calculates the hysteresis correction amount Thys in a manner that makes the absolute value of the target steering torque Th* larger when turning the wheel than when returning it to its original position. The hysteresis processing M22 includes a process that variably sets the hysteresis correction amount Thys according to the vehicle speed V.

[0046] The additive processing M24 calculates the target steering torque Th* by adding the hysteresis correction Thys to the baseline target torque Thb*.

[0047] The target reaction force calculation process M26 takes the steering torque Th and the target steering torque Th* as inputs to calculate the target reaction force Ts* corresponding to the steering reaction force applied to the steering wheel 12. The target reaction force Ts* is actually the command value relative to the reaction force motor 20. The value obtained by multiplying the target reaction force Ts* by a coefficient corresponding to the reduction ratio of the reduction mechanism 16 becomes the steering reaction force.

[0048] The reaction force operation process M30 takes the target reaction force Ts*, currents iu1, iv1, iw1, and rotation angle θa as inputs and outputs an operation signal MSs relative to the reaction force inverter 22. The reaction force operation process M30 includes a process for calculating the current command value of the dq axis based on the target reaction force Ts*. Furthermore, the reaction force operation process M30 includes a process for calculating the current of the dq axis based on the currents iu1, iv1, iw1, and rotation angle θa. Moreover, the reaction force operation process M30 includes a process for calculating the operation signal MSs of the reaction force inverter 22, using the dq axis current as the command value.

[0049] exist Figure 3 The details of the target reaction force calculation for M26 are shown.

[0050] The deviation calculation process M40 is the process of calculating the torque deviation ΔTh obtained by subtracting the target steering torque Th* from the steering torque Th.

[0051] The proportional element M50 takes the torque deviation ΔTh as input and outputs a value proportional to ΔTh. Specifically, the proportional gain multiplication process M52 multiplies the torque deviation ΔTh by the proportional gain Kp. The proportional phase controller M54 performs low-pass filtering on the output value of the proportional gain multiplication process M52. Specifically, the proportional phase controller M54 is a first-order delay filter as described below.

[0052] 1 / (Tp·s+1)

[0053] In addition, "Tp" is the time constant, and "s" is a linear operator representing the first-order time derivative.

[0054] The output value of the proportional phase controller M54 is the output value of the proportional element M50.

[0055] The differential element M60 takes the torque deviation ΔTh as input and outputs a value proportional to the time differential of the torque deviation ΔTh. Specifically, the linear operator M62 takes the torque deviation ΔTh as input and outputs the time differential of the torque deviation ΔTh. The differential gain multiplication process M64 multiplies the output value of the linear operator M62 by the differential gain Kd. The differential phase controller M66 advances the phase of a specified frequency component of the output value of the differential gain multiplication process M64. The differential phase controller M66 is a zero-order phase controller as shown below.

[0056] {ad·Td·s+1} / (Td·s+1)

[0057] Here, "Td" is the time constant. And, "ad > 1".

[0058] exist Figure 4 The diagram shows the phase line of the differential phase controller M66. (See figure.) Figure 4 As shown, the differential phase controller M66 advances the phase of frequency components near the specified center frequency f1. The output value of the differential phase controller M66 is the output value of the differential element M60.

[0059] return Figure 3 The addition process M70 is the process of adding the output value of the proportional element M50 and the output value of the differential element M60 as the output of the PD operation quantity Tpd.

[0060] The second operation calculation process M80 is a process for generating the target reaction force Ts* and calculating operation quantities other than the PD operation quantity Tpd. The second operation calculation process M80 may, for example, include at least one of the processes (A) to (H) described below.

[0061] Processing (A) is the process of calculating the operating quantity corresponding to the cumulative value obtained by subtracting the steering torque Th from the inferred axial force. The inferred axial force is the torque equivalent of the reaction force motor 20. The inferred axial force is input through PU72 and the values ​​of currents iu1, iv1, and iw1 are calculated.

[0062] Process (B) is the cumulative value of the difference between the steering torque Th and the target steering torque Th* multiplied by the integral gain, which is used as the operating quantity.

[0063] Processing (C) is the process of calculating the amount of operation used to control the steering torque inferred from the disturbance observer to the target steering torque Th*. Processing (C) takes the torque of the reaction motor 20 calculated based on the steering angle θh, current iu1, iv1, and iw1 as input.

[0064] Process (D) is the process of calculating the open-loop operating quantity with the steering torque Th as input.

[0065] Processing (E) is the process of calculating the open-loop operating quantity with the target steering torque Th* as input.

[0066] Process (F) is a process of calculating the amount of operation to apply a force to the steering shaft 14 to prevent the pinion angle θp from increasing further when the pinion angle θp is above a specified value.

[0067] Process (G) is a process that calculates the amount of operation to be applied to the steering shaft 14 to prevent the steering angle θh from increasing further when the magnitude of the steering angle θh is above a specified value.

[0068] Processing (H) is the process that calculates the amount of operation used to control the steering angle θh by feedback control to convert the pinion angle θp into the steering angle θh. Furthermore, the converted steering angle is calculated by PU72 based on the target pinion angle, and processing M14 calculates the angle ratio determined by the vehicle speed V.

[0069] The addition process M82 is a process that adds the PD operation quantity Tpd to the second operation quantity Ts2 output by the second operation quantity calculation process M80 to calculate the target reaction force Ts*.

[0070] <The function and effects of this implementation method>

[0071] exist Figure 5A as well as Figure 5B The diagram shows a Bode plot of the steering control system 10 of this embodiment, particularly the steering wheel 12, steering shaft 14, and reaction force actuator Ar. Figure 5A It is a gain graph. Figure 5B It is a phase line diagram.

[0072] like Figure 5A as well as Figure 5B As shown, in this embodiment, the device has a resonant frequency in a frequency range slightly smaller than frequency f2. Furthermore, frequency f2 is the anti-resonant frequency. The generation of both resonance and anti-resonance is due to the torque sensor 80 having a torsion bar, thus forming a dual inertial system with inertial systems connected to both sides of the torsion bar.

[0073] Resonance and anti-resonance phenomena are manifested in the region where the steering torque Th is relatively large. This is believed to be because in the region where the steering torque Th is small, the friction component becomes significant when the steering wheel 12 is shifted, making resonance and anti-resonance phenomena less noticeable. Additionally, Figure 5A as well as Figure 5B As shown in this embodiment, the device characteristics tend to become more pronounced in the case of an electric steering system. This is presumably because the load applied to the steering wheel 12 is small when the magnitude of the steering torque Th becomes sufficient to overcome the aforementioned frictional components. That is, when the steering wheel 12 and the steering wheel 44 are mechanically connected, a load torque from the steering wheel 44 side is applied to the steering wheel 12. It is presumed that this load torque tends to suppress resonance and cause anti-resonance phenomena to manifest.

[0074] At the resonant frequency, there is a concern about vibrations caused by the control of the target steering torque Th*. To address this issue, the responsiveness decreases when the proportional gain Kp is reduced.

[0075] exist Figure 6A as well as Figure 6B The Bode plot is shown when the controller of this embodiment and the comparative example are used. Figure 6A It is a gain graph. Figure 6B It's a phase line diagram. In Figure 6A as well as Figure 6B In the diagram, the solid lines represent the gain and phase plots of this embodiment. Figure 6A as well as Figure 6B In the diagram, the dashed lines represent the gain and phase plots of the comparative example. The comparative example is the case without the proportional phase controller M54 and the differential phase controller M66. The comparative example is an example of reducing the gain, such as reducing the proportional gain Kp, to suppress instability caused by resonance.

[0076] In the comparative example, a phase delay is introduced to reduce gain. In contrast, in the illustrated embodiment, the gain is increased and the phase delay is suppressed by using a proportional phase controller M54 and a differential phase controller M66.

[0077] exist Figure 7A as well as Figure 7B The above is shown in the figure. Figure 6A as well as Figure 6B The characteristics of the ramp response. Figure 7A This indicates the device response characteristics of this embodiment. Figure 7B Indicates in Figure 6A as well as Figure 6B The device response characteristics of the comparative example are shown with a single-dotted line.

[0078] like Figure 7A As shown, in this embodiment, by improving responsiveness, the steering torque Th follows the target steering torque Th*. In contrast, as... Figure 7B As shown, in the comparative example, due to the low responsiveness, the steering torque Th has a low degree of following the target steering torque Th*.

[0079] exist Figure 8A as well as Figure 8B The step response characteristics of the steering torque Th are shown in the diagram. Specifically, Figure 8A This indicates the step response characteristics of the steering torque Th in this embodiment. Figure 8B This represents the step response characteristics of the steering torque Th in the comparative example. The comparative example does not have the proportional phase controller M54 and the differential phase controller M66. Figure 8B The comparison example shown is where the gain is not compared to... Figure 6A as well as Figure 6B The lower example is shown by a single-dot dash.

[0080] like Figure 8BAs shown, in the comparative example, vibrations occur relative to the step response, and the control becomes unstable. This is due to... Figure 5A as well as Figure 5B The phenomenon caused by the characteristics of the device shown. In contrast, as... Figure 8A As shown, in this embodiment, vibration is suppressed. This is achieved by delaying the phase of the proportional element M50 by the proportional phase controller M54 and advancing the phase of the differential element M60 by the differential phase controller M66.

[0081] In other words, to suppress vibration, the phase of the proportional element M50 is delayed; on the other hand, to improve responsiveness, the phase of the differential element M60 is advanced. In other words, the actual advance of the differential element M60 relative to the proportional element M50 is expanded, relative to the phase advance of the proportional element M50, which is determined by the proportional gain Kp and the differential gain Kd. Thus, a balance between stability and responsiveness can be achieved.

[0082] exist Figure 9A as well as Figure 9B The diagram shows the shifts in the output values ​​of the column shaft torque, the proportional element M50, and the derivative element M60. The column shaft torque is the torque corresponding to the sum of the steering control torque Th and the torque of the reaction motor 20. Figure 9A This indicates a shift in relation to this implementation method. Figure 9B This indicates the shift in the comparison example. This comparison example has no gain compared to... Figure 6A as well as Figure 6B The comparative example shown is a lower-level example. In particular, the comparative example utilizes a setting that does not produce vibration in the steering system where the steering wheel 12 is mechanically connected to the steering wheel 44.

[0083] like Figure 9B As shown, in the comparative example, the output values ​​of the column shaft torque, proportional element M50, and derivative element M60 vibrate due to the increase in column shaft torque. The state where the column shaft torque is far from zero is the state where the friction generated by the steering shaft 14 has been removed. In the state where friction has been removed, the output values ​​of the column shaft torque, proportional element M50, and derivative element M60 vibrate. It is presumed that this is caused by the steering shaft 14 being in a near-unloaded state in the case of the electric steering system 10, in the state where friction has been removed.

[0084] Based on the above-described embodiment, the functions and effects described below can be further obtained.

[0085] (1-1) The differential phase controller M66 is set as a phase controller that advances the phase of a specified frequency component. Furthermore, by setting the center frequency f1 to a value near the frequency "f2" representing the anti-resonance phenomenon, the responsivity near the frequency "f2" representing the anti-resonance phenomenon can be improved, and the excessive enhancement of the responsivity in other frequency bands can be suppressed. Additionally, the center frequency f1 can also be a frequency higher than the frequency "f2" representing the anti-resonance phenomenon.

[0086] (1-2) Set the proportional phase controller M54 as a single delay element. As a result, the adjustment element based on the proportional phase controller M54 becomes a single cutoff frequency, so it is easy to reduce the responsiveness of the frequency band in which the responsiveness of the proportional element M50 is to be reduced.

[0087] (1-3) Set the differential phase controller M66 to a phase controller with a relative order of "0" and both the numerator and denominator orders of "1". This can suppress the situation where there are too many suitable parameters.

[0088] (1-4) PU72 operates the inverter 22 for the reaction force when the steering wheel 12 and steering wheel 44 are mechanically separated. In other words, in the electric steering system, the inverter 22 is used. Figure 3 Control. Even in steering systems where the steering wheel 12 is mechanically connected to the steering wheel 44, which have controllers that do not produce vibration, there are concerns about vibration occurring in electric steering systems. Therefore, Figure 3 Its control and utilization value is particularly high.

[0089] <Second Implementation>

[0090] Hereinafter, the second embodiment will be described with reference to the accompanying drawings, focusing on the differences from the first embodiment.

[0091] exist Figure 10 The details of the target reaction force calculation process M26 in this embodiment are shown. Furthermore, in Figure 10 For convenience, regarding... Figure 3 The processes shown are labeled with the same reference numerals.

[0092] like Figure 10 As shown, in this embodiment, the proportional phase controller M54 is not included. However, in this embodiment, the differential phase controller M66 is included. Therefore, compared to the case where both the proportional phase controller M54 and the differential phase controller M66 are not included, the advance of the phase of the differential element M60 relative to the phase of the proportional element M50 can be increased.

[0093] <The function and effects of the second embodiment>

[0094] exist Figure 11A as well as Figure 11B The step response characteristics of this embodiment and the comparative example are shown in the figure. In detail, Figure 11A The step response characteristics of the steering torque Th in this embodiment are shown. Figure 11B The step response characteristics of the steering torque Th in the comparative example are shown. Comparative example and... Figure 8B The situation is the same.

[0095] like Figure 11A as well as Figure 11B As shown, even in this embodiment, stability can be improved without reducing responsiveness.

[0096] <Third Implementation Method>

[0097] Hereinafter, the third embodiment will be described with reference to the accompanying drawings, focusing on the differences from the first embodiment.

[0098] exist Figure 12 The details of the target reaction force calculation process M26 in this embodiment are shown. Furthermore, in Figure 12 For convenience, regarding... Figure 3 The processes shown are labeled with the same reference numerals.

[0099] like Figure 12 As shown, in this embodiment, a differential phase controller M66 is not included. However, in this embodiment, a proportional phase controller M54 is also included. Therefore, compared to the case where both the proportional phase controller M54 and the differential phase controller M66 are not included, the advance of the phase of the differential element M60 relative to the phase of the proportional element M50 can be increased.

[0100] <The function and effects of the third embodiment>

[0101] exist Figure 13A as well as Figure 13B The step response characteristics of this embodiment and the comparative example are shown in the figure. In detail, Figure 13A The step response characteristics of the steering torque Th in this embodiment are shown. Figure 13B The step response characteristics of the steering torque Th in the comparative example are shown. Comparative example and... Figure 8B The situation is the same.

[0102] like Figure 13A as well as Figure 13B As shown, even in this embodiment, stability can be improved without reducing responsiveness.

[0103] <Fourth Implementation>

[0104] Hereinafter, the fourth embodiment will be described with reference to the accompanying drawings, focusing on the differences from the first embodiment.

[0105] exist Figure 14 The details of the target reaction force calculation process M26 in this embodiment are shown. Furthermore, in Figure 14 For convenience, regarding... Figure 3 The processes shown are labeled with the same reference numerals.

[0106] like Figure 14 As shown, in this embodiment, in addition to the first differential phase controller, namely the differential phase controller M66, a second differential phase controller, namely the differential phase controller M68, is also provided. The differential phase controller M68 is a primary delay element as described below.

[0107] 1 / (Td1·s+1)

[0108] The cutoff frequency of the differential phase controller M68 is higher than that of the phase controller M68. Figure 4 The center frequency f1 shown is a high frequency. That is, the differential phase controller M68 is a phase controller that delays the phase of the high-frequency band compared to the frequency that needs to be advanced by the differential phase controller M66.

[0109] <The function and effects of the fourth embodiment>

[0110] The differential phase controller M66 advances the phase of the frequency band that generates phase delay due to anti-resonance. However, the differential phase controller M66 also advances the phase of frequency domains higher than the frequency band that generates phase delay due to anti-resonance. Excessive advancement of the phase in higher frequency bands can easily cause noise in the steering system 10. Therefore, in this embodiment, the differential phase controller M68 advances the phase delay of the frequency domain higher than the frequency band that generates phase delay due to anti-resonance by the differential phase controller M66. This suppresses the generation of noise in the steering system 10.

[0111] <Fifth Implementation>

[0112] Hereinafter, the fifth embodiment will be described with reference to the accompanying drawings, focusing on the differences from the fourth embodiment.

[0113] exist Figure 15 The details of the target reaction force calculation process M26 in this embodiment are shown. Furthermore, in Figure 15 For convenience, regarding... Figure 14 The processes shown are labeled with the same reference numerals.

[0114] like Figure 15As shown, in this embodiment, the input to the differential element M60 is set to the steering torque Th. Therefore, the linear operator M62 becomes the process for calculating the first-order time derivative of the steering torque Th. Furthermore, the differential gain multiplication process M64 becomes the process for multiplying the first-order time derivative of the steering torque Th by the differential gain Kd. Additionally, the PD operation quantity is set to the value obtained in the subtraction process M70a by subtracting the output value of the differential element M60 from the output value of the proportional element M50.

[0115] Thus, the PD operation quantity Tpd in this embodiment is the operation quantity of the advance differential PD control.

[0116] <Other Implementation Methods>

[0117] Furthermore, this embodiment can be modified as follows. This embodiment and the following modifications can be combined with each other within the scope of technical inconsistency.

[0118] Regarding the element of proportion

[0119] For example, the ratio can also be set upstream of the proportional gain multiplication process using the phase controller M54.

[0120] "On Differential Elements"

[0121] For example, the differential phase controller M66 can be positioned between the linear operator M62 and the differential gain multiplication process M64. Furthermore, the differential phase controller M66 can also be positioned upstream of the linear operator M62.

[0122] For example, the differential phase controller M68 can be positioned between the differential phase controller M66 and the differential gain multiplication process M64. Furthermore, the differential phase controller M68 can also be positioned between the linear operator M62 and the differential gain multiplication process M64.

[0123] Regarding proportional phase controllers

[0124] • The phase controller used for proportional applications is not limited to a single-order delay element. For example, it can also be a double-order delay element. Additionally, as described below, it can also be a phase controller with a relative order of zero.

[0125] αp·(Tp2·s+1) / (Tp1·s+1)

[0126] Wherein, “αp<1”.

[0127] "Regarding a differential phase controller for advancing the phase at a specified frequency"

[0128] • The differential phase controller that advances the phase of a specified frequency is not limited to the components illustrated in the above embodiments.

[0129] Regarding the phase controller for the second differential.

[0130] • The embodiment of setting the differential phase controller M68 is not limited to the structure of setting the proportional phase controller M54 in the proportional element M50.

[0131] The differential phase controller used to delay the phase, i.e., the second differential phase controller, is not limited to a primary delay element. For example, it can also be a secondary delay element. In addition, as described below, it can also be a phase controller with a relative order of zero.

[0132] αd1·(Td2·s+1) / (Td1·s+1)

[0133] Wherein, “αd1<1”.

[0134] Regarding the phase controller for expansion

[0135] • When the PD operating quantity Tpd is the operating quantity of the advance differential PD control, the phase controller used for expansion is not limited to... Figure 15 The controller shown is an example. For example, it could also be... Figure 10 , Figure 12 Examples include phase controllers.

[0136] • The phase controller for amplification is not limited to the controllers illustrated in the above embodiments and their variations. For example, both the proportional phase controller and the differential phase controller may be configured as first-order delay elements. However, the degree of phase delay compensation caused by the proportional phase controller is made greater than the degree of phase delay compensation of the differential element. Thus, it is also possible to construct a controller that amplifies the advance of the phase of the differential element relative to the phase of the proportional element.

[0137] "Regarding the operating parameters used to control the steering torque to the target steering torque"

[0138] The operating quantity used to control the steering torque to the target steering torque is not limited to the target reaction force Ts*. In other words, it is not limited to the target value of the torque for the reaction force motor 20. For example, if the reaction force motor 20 is a surface magnet synchronous motor, it can also be set to the commanded value of the q-axis current. In addition, if the reaction force motor 20 is an embedded magnet synchronous motor, it can also be a combination of the commanded values ​​of the d-axis current and the q-axis current.

[0139] • The operating quantity used to control the steering torque to the target steering torque is not limited to the variable representing the reaction force applied to the steering wheel 12. For example, as described in the "About Steering Device" section below, in the case of a device capable of transmitting power between the steering wheel 12 and the steering wheel 44, it becomes the variable representing the torque that assists the driver in applying torque to the steering wheel 12.

[0140] Regarding steering torque control processing

[0141] • Steering torque control processing, i.e., target reaction force calculation processing M26, does not necessarily include the second operation amount calculation processing M80.

[0142] "Calculation and processing of the benchmark target torque Thb*"

[0143] The process of calculating the reference target torque Thb* by using the axial force Taf as input is not limited to the process of using the vehicle speed V as input in addition to the axial force Taf.

[0144] It is not necessary to use the axial force Taf as input to calculate the reference target torque Thb*. For example, the steering torque Th and vehicle speed V can also be used as inputs to calculate the reference target torque Thb*. This can be achieved, for example, by performing a mapping table operation on the reference target torque Thb* by PU72 while the mapping table data is stored in the storage device 74. Here, the mapping table data is data that takes the steering torque Th and vehicle speed V as input variables and sets the reference target torque Thb* as the output variable.

[0145] Regarding operational procedures

[0146] • The control method for the reaction motor 20 is not limited to current feedback processing of the dq axis. For example, if a DC motor is used as the reaction motor 20 and the drive circuit is set as an H-bridge circuit, it is sufficient to control only the current flowing in the reaction motor 20.

[0147] The operation processing is not necessarily limited to setting the command value of the motor such as the reaction motor 20 by setting the PD operation amount Tpd or the sum of the PD operation amount and the second operation amount Ts2. For example, it may also include processing to calculate the command value of the rotation angle of the reaction motor 20 by inputting the PD operation amount Tpd or the sum of the PD operation amount and the second operation amount Ts2. This can be performed, for example, as follows: PU72 calculates the torque applied to the steering shaft 14 based on the PD operation amount Tpd or the sum of the PD operation amount and the second operation amount Ts2. This calculation process may also take into account the steering torque Th. Furthermore, PU72 calculates the rotation angle of the steering shaft 14 by inputting the torque applied to the steering control device model. PU72 calculates the command value of the rotation angle of the reaction motor 20 based on this rotation angle.

[0148] "Control of steering angle"

[0149] Alternatively, instead of the pinion angle feedback processing M16, a process can be used to control the detected value of the movement of the steering shaft 40 to a target value through feedback control. In this case, compared to the above embodiment, the control quantity related to the pinion angle θp is replaced with the control quantity related to the movement of the steering shaft 40.

[0150] • Steering angle control does not necessarily include processing for calculating the operational quantity used to control the steering angle, such as the pinion angle θp, via feedback control. For example, steering angle control may also include processing for calculating the operational quantity used to control the steering angle to a target value via open-loop control. Moreover, steering angle control may also include processing for calculating the sum of the operational quantity used for open-loop control and the operational quantity used for feedback control.

[0151] • The control method for the steering motor 60 is not limited to current feedback processing of the dq axis. For example, if a DC motor is used as the steering motor 60 and the drive circuit is set as an H-bridge circuit, it is sufficient to control only the current flowing in the steering motor 60.

[0152] Regarding operating components

[0153] The control components operated by the driver to steer the vehicle are not limited to the steering wheel 12. For example, it could also be a joystick.

[0154] Regarding motors that are mechanically connected to operating components.

[0155] (a) Regarding the reaction force actuator Ar

[0156] The reaction force motor 20, which is mechanically connected to the steering wheel 12, is not limited to a three-phase brushless motor. For example, it can also be a brushed DC motor.

[0157] (b) Regarding the motor drive circuit

[0158] • The drive circuit for the motor, which is mechanically connected to the operating components, is not limited to the reaction force inverter 22. For example, it could also be an H-bridge circuit.

[0159] (c) Other

[0160] • It is not necessary to have a speed reduction mechanism 16.

[0161] Regarding the steering control device

[0162] The steering control device is not limited to a device that includes a PU72 and a storage device 74 and performs software processing. For example, it may also include dedicated hardware circuitry such as an ASIC that performs at least a portion of the processing performed in the above embodiment. That is, the control device may also include a processing circuitry having any of the following structures (a) to (c): (a) A processing circuitry having a processing device that performs all of the above processing according to a program, and a program storage device such as a storage device for storing the program. (b) A processing circuitry having a processing device that performs a portion of the above processing according to a program, a program storage device, and dedicated hardware circuitry that performs the remaining processing. (c) A processing circuitry having dedicated hardware circuitry that performs all of the above processing. Here, there may be multiple software execution devices that include processing devices and program storage devices. In addition, there may be multiple dedicated hardware circuitry.

[0163] Regarding steering actuators

[0164] • As a steering actuator At, for example, an actuator in which the steering motor 60 is mounted on the same axis as the steering shaft 40 can also be used. Moreover, for example, an actuator connected to the steering shaft 40 via a belt reducer using a ball screw mechanism can also be used.

[0165] • The steering actuator At is not limited to a structure in which the right steering wheel 44 and the left steering wheel 44 are linked. In other words, it can also be an actuator that can independently control the right steering wheel 44 and the left steering wheel 44.

[0166] Regarding the steering control system

[0167] The steering control device capable of changing the relationship between the steering angle and the steering wheel angle is not limited to a steering control device that cuts off the power transmission between the steering wheel 12 and the steering wheel 44. For example, a steering control device capable of changing the relationship between the steering angle and the steering wheel angle can be constructed by making the gear capable of transmitting power between the steering wheel 12 and the steering wheel 44 a variable gear. Furthermore, it is not limited to a steering control device capable of changing the relationship between the steering angle and the steering wheel angle. For example, a steering control device that mechanically connects the steering wheel 12 and the steering wheel 44 can also be used.

Claims

1. A steering control device, wherein the operation of a motor is mechanically connected to a control component operated by a driver for steering the vehicle, wherein... The aforementioned steering control device is configured to perform steering torque control processing and operation processing. The aforementioned steering torque control process includes calculating the operating amount for controlling the steering torque to the target steering torque using a proportional element and a differential element corresponding to the difference between the steering torque and the target steering torque. The above-described operation process is for controlling the torque of the motor based on the described operation amount, and involves operating the drive circuit of the motor. The aforementioned steering torque is the torque input to the aforementioned operating components. At least one of the aforementioned proportional element and the aforementioned differential element is provided with a phase controller for amplification. The aforementioned phase controller is configured to amplify the advance of the phase of the differential element relative to the phase of the proportional element.

2. The steering control device according to claim 1, wherein, The aforementioned scaling element includes the aforementioned amplification phase controller, i.e., the scaling phase controller. The aforementioned ratio is configured using a phase controller to delay the phase of the aforementioned ratio element. The aforementioned differential element includes the aforementioned phase controller for amplification, i.e., the phase controller for differentiation. The aforementioned differential phase controller is configured to advance the phase of the aforementioned differential element.

3. The steering control device according to claim 1, wherein, The aforementioned scaling element includes the aforementioned amplification phase controller, i.e., the scaling phase controller. The aforementioned ratio is configured using a phase controller to delay the phase of the aforementioned ratio element.

4. The steering control device according to claim 1, wherein, The aforementioned differential element includes the aforementioned phase controller for amplification, i.e., the phase controller for differentiation. The aforementioned differential phase controller is configured to advance the phase of the aforementioned differential element.

5. The steering control device according to claim 2 or 4, wherein, The aforementioned differential phase controller is configured to advance the phase of a specified frequency component.

6. The steering control device according to claim 5, wherein, The aforementioned differential phase controller is the first differential phase controller. In addition to the first differential phase controller mentioned above, the aforementioned differential element also includes a second differential phase controller. The aforementioned second differential phase controller is configured to delay the phase of the cycle component in the output of the aforementioned differential element that is higher than the aforementioned specified frequency component.

7. The steering control device according to claim 2 or 3, wherein, The above ratio is a delay element using a phase controller.

8. The steering control device according to claim 2 or 4, wherein, The aforementioned differential phase controller is a phase controller with a relative number of 0.

9. The steering control device according to claim 6, wherein, The aforementioned second differential phase controller is a primary delay element.

10. The steering control device according to any one of claims 1, 2, and 4, wherein, The aforementioned differential element input is the difference between the aforementioned steering torque and the aforementioned target steering torque.

11. The steering control device according to any one of claims 1, 2, and 4, wherein, The aforementioned differential element is input to the aforementioned steering torque.

12. The steering control device according to any one of claims 1 to 4, wherein, The above-mentioned operation process is performed while the above-mentioned operating components are mechanically separated from the steering wheels of the vehicle.

13. A steering control method comprising a steering control method for operating a motor mechanically connected to a control component operated by a driver for steering the vehicle, wherein, The aforementioned steering control method includes steps for performing steering torque control processing and steps for performing operation processing. The aforementioned steering torque control process includes calculating the operating amount for controlling the steering torque to the target steering torque using a proportional element and a differential element corresponding to the difference between the steering torque and the target steering torque. The above-described operation process is for controlling the torque of the motor based on the described operation amount, and involves operating the drive circuit of the motor. The aforementioned steering torque is the torque input to the aforementioned operating components. The aforementioned steering torque control process includes a process of increasing the advance of the phase of the differential element relative to the phase of the proportional element by setting an amplification phase controller for at least one of the two elements, the proportional element and the differential element.

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