JP2020001657A - Steering control device - Google Patents

Abstract

To provide a steering control device capable of changing a switching mode of an electromagnetic clutch.SOLUTION: A clutch control signal output unit 142 executes PI control as a current feedback control to thereby calculate a clutch voltage command value Vc*, and outputs a clutch control signal Scl based on the clutch voltage command value Vc*. In a clutch proportional tool 152 of the clutch control signal output unit 142, an engagement-time proportional gain is set as a proportional gain Gpc used in an SBW mode, and an opening-time proportional gain is set as a proportional gain Gpc used in an EPS mode. In a clutch integrator 153, an engagement-time integral gain is set as an integral gain Gic used in the EPS mode, and an opening-time integral gain is set as an integral gain Gic used in the SBW mode.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a steering control device.

  2. Description of the Related Art Conventionally, as one type of steering device, there is a steer-by-wire type in which power transmission between a steering unit steered by a driver and a steering unit that steers steered wheels in accordance with the steering of the driver is separated. . For example, Patent Document 1 discloses a steering control device that controls a steering device in which a steering unit and a turning unit can be mechanically connected and disconnected by an electromagnetic clutch.

  In the steering control device of this document, normally, a steer-by-wire mode (SBW mode) in which power transmission between the steering section and the steered section is cut off by opening the electromagnetic clutch. In the SBW mode, a steering-side actuator having a steering-side motor applies a steering reaction force against the steering of the driver to the steering section, and a steered wheel is turned to the steering section by a steering-side actuator having the steering-side motor. The traveling direction of the vehicle is changed by applying a turning force to be turned. Also, for example, when the drive voltage of the turning-side actuator is reduced, an electric power steering mode (EPS mode) is established in which the electromagnetic clutch is engaged so that power can be transmitted between the steering section and the turning section. The steering side actuator changes the traveling direction of the vehicle by applying an assisting force for assisting the driver in steering.

JP 2018-52205 A

  By the way, the above-described conventional configuration does not disclose a switching mode of a speed or the like when switching the engagement / disengagement state of the electromagnetic clutch. For this reason, the switching mode of the electromagnetic clutch cannot be changed according to, for example, the specifications of the vehicle, and there is still room for improvement in this respect.

  An object of the present invention is to provide a steering control device capable of changing a switching mode of an electromagnetic clutch.

  A steering control device that solves the above problem includes a steering unit, a steering unit that steers steered wheels in accordance with steering input to the steering unit, and mechanically disconnects the steering unit and the steering unit. A steering device having a contactable electromagnetic clutch as a control target, and supplying a drive current to the electromagnetic clutch to thereby transmit the power of the electromagnetic clutch from the steering section to the steering section; A clutch control unit that switches between an open state in which power transmission from the unit to the steering unit is interrupted. The clutch control unit sets an actual clutch current command value that is a target value of a drive current supplied to the electromagnetic clutch. A current feedback control for following a clutch current which is a drive current is performed, and the clutch control unit includes a control gain used for a current feedback control of the electromagnetic clutch. And gain when engaged to be used when switching from the engaged state to the open state, the gain at the open used in case of switching from the open state to the engagement state is set, respectively.

  According to the above configuration, the control gain used for the current feedback control of the drive current (clutch current) supplied to the electromagnetic clutch is set according to whether the clutch is in the engaged state or the released state. The mode of switching between the engaged and released states can be suitably adjusted.

  The steering control device further includes a steering-side control unit that controls an operation of a steering-side motor capable of applying a steering reaction force against the steering input to the steering unit, and the steering-side control unit includes the steering-side motor. And a current feedback control that causes a steering-side motor current that is an actual drive current to follow a steering-side current command value that is a target value of the drive current supplied to the steering-side control unit. It is preferable that a gain at the time of engagement used in the engagement state and a gain at the time of release used in the release state are set as control gains used for the current feedback control of the side motor.

According to the above configuration, it is possible to suitably control the operation of the steering motor in accordance with whether the electromagnetic clutch is in the engaged state or the released state.
In the steering control device, further includes a turning control unit that controls the operation of a turning motor that can apply a turning force to turn the steered wheels to the turning unit, and the turning control unit includes: Performing a current feedback control for following a turning-side motor current that is an actual driving current to a turning-side current command value that is a target value of a driving current supplied to the turning-side motor; In the side control unit, a gain at the time of engagement used in the engaged state and a gain at the time of opening used in the released state are set as control gains used for current feedback control of the turning side motor. preferable.

  According to the above configuration, it is possible to suitably control the operation of the steering-side motor according to whether the electromagnetic clutch is in the engaged state or the released state.

  According to the present invention, the switching mode of the electromagnetic clutch can be changed.

FIG. 1 is a schematic configuration diagram of a steer-by-wire steering device. FIG. 2 is a block diagram of a steering control device. FIG. 4 is a block diagram of a steering microcomputer and a turning microcomputer in an SBW mode. FIG. 4 is a block diagram of a steering-side microcomputer (steering-side microcomputer) in an EPS mode. FIG. 2 is a block diagram of a clutch microcomputer. 5 is a graph showing an example of a change in a clutch current command value.

Hereinafter, an embodiment of a steering control device will be described with reference to the drawings.
As shown in FIG. 1, a steer-by-wire type steering device 2 to be controlled by a steering control device 1 includes a steering unit 3 steered by a driver, and steered wheels 4 according to steering of the steering unit 3 by the driver. , And an electromagnetic clutch 6 capable of mechanically connecting and disconnecting the steering unit 3 and the steering unit 5.

  The steering section 3 includes a steering shaft 12 to which a steering wheel 11 is fixed. The steering shaft 12 is configured by connecting a column shaft 13 and an input intermediate shaft 14 in order from the steering wheel 11 side. The input intermediate shaft 14 is connected to an input side plate 42 of the electromagnetic clutch 6 described later.

  The steering section 3 is provided with a steering actuator 16 capable of applying a steering force to the steering shaft 12. The steering-side actuator 16 includes a steering-side motor 17 serving as a driving source, and a steering-side reducer 18 that reduces the rotation of the steering-side motor 17 and transmits the rotation to the column shaft 13. It should be noted that a three-phase brushless motor is employed as the steering side motor 17 of the present embodiment.

  The steering unit 5 includes a first pinion shaft 21 and a rack shaft 22 connected to the first pinion shaft 21. An output intermediate shaft 24 is connected to an upper end of the first pinion shaft 21, and the output intermediate shaft 24 is connected to an output plate 43 of the electromagnetic clutch 6 described later. The first pinion shaft 21 and the rack shaft 22 are arranged at a predetermined intersection angle, and the first pinion teeth 21a formed on the first pinion shaft 21 and the first rack teeth 22a formed on the rack shaft 22 are formed. The first rack-and-pinion mechanism 25 is configured by meshing the two. A tie rod 26 is connected to both ends of the rack shaft 22, and a tip of the tie rod 26 is connected to a knuckle (not shown) to which the steered wheels 4 are attached.

  The turning portion 5 is provided with a turning-side actuator 31 for applying a turning force for turning the steered wheels 4 to the rack shaft 22 via a second pinion shaft 32. The turning-side actuator 31 includes a turning-side motor 33 serving as a drive source, and a turning-side reduction gear 34 that reduces the rotation of the turning-side motor 33 and transmits the rotation to the second pinion shaft 32. It should be noted that a three-phase brushless motor is employed as the steering-side motor 33 of the present embodiment. The second pinion shaft 32 and the rack shaft 22 are arranged at a predetermined intersection angle, and a second pinion tooth 32a formed on the second pinion shaft 32 and a second rack tooth 22b formed on the rack shaft 22 are provided. The second rack-and-pinion mechanism 35 is configured by meshing with.

  The electromagnetic clutch 6 is configured such that the input side plate 42 and the output side plate 43 are brought into contact with and separated from each other in accordance with a magnetic attraction force generated by energization of the coil 41, thereby switching between an engaged state and a released state. ing. The electromagnetic clutch 6 of the present embodiment employs a so-called normally closed electromagnetic clutch which is engaged when the coil 41 is not energized and is released when the coil 41 is energized.

  In the steering device 2 configured as described above, the steer-by-wire (SBW) mode is set when the electromagnetic clutch 6 is released. In the SBW mode, the second pinion shaft 32 is rotationally driven by the turning-side actuator 31 in response to the driver's steering, and this rotation is converted into the axial movement of the rack shaft 22 by the second rack and pinion mechanism 35. Thus, the steered angle of the steered wheels 4 is changed. At this time, a steering reaction force against the driver's steering is applied to the steering wheel 11 from the steering-side actuator 16.

  The steering device 2 is in an electric power steering (EPS) mode when the electromagnetic clutch 6 is engaged. In the EPS mode, the rotation of the steering shaft 12 accompanying the steering operation is converted into the axial movement of the rack shaft 22 by the first rack and pinion mechanism 25, and this axial movement is transmitted to the knuckle via the tie rod 26. Thus, the steered angle of the steered wheels 4 is changed. At this time, an assist force for assisting the driver in steering is applied from at least one of the steering-side actuator 16 and the turning-side actuator 31.

Next, the electrical configuration of the present embodiment will be described.
The steering control device 1 includes a steering-side ECU 51 as a steering-side control unit that controls the operation of the steering-side actuator 16 (the steering-side motor 17), and a steering control that controls the operation of the steering-side actuator 31 (the steering-side motor 33). A turning-side ECU 52 as a rudder-side control unit and a clutch ECU 53 as a clutch control unit for controlling the operation of the electromagnetic clutch 6 are provided. Each of the ECUs 51 to 53 includes a central processing unit (CPU) and a memory (not shown), and various controls are executed by the CPU executing a program stored in the memory at each predetermined calculation cycle.

  A vehicle speed sensor 54 for detecting a vehicle speed SPD of the vehicle and a torque sensor 55 for detecting a steering torque Th applied to the steering shaft 12 are connected to the steering-side ECU 51 and the turning-side ECU 52, respectively. The torque sensor 55 is provided closer to the steering wheel 11 than the portion of the column shaft 13 connected to the steering-side actuator 16 (steering-side speed reducer 18), and outputs the steering torque Th based on the torsion of the torsion bar 56. To detect. The steering-side ECU 51 is connected to a steering-side rotation sensor 57 that detects the rotation angle θs of the steering-side motor 17 as a detection value indicating the steering amount of the steering unit 3. A turning-side rotation sensor 58 that detects the rotation angle θt of the turning-side motor 33 as a detection value indicating the turning amount of the turning-side is connected. Further, the steering-side ECU 51, the turning-side ECU 52, and the clutch ECU 53 are connected to each other. The steering-side ECU 51 and the turning-side ECU 52 control the operations of the steering-side motor 17 and the turning-side motor 33, respectively, based on the various state quantities detected by the respective sensors. Alternatively, the operation of the electromagnetic clutch 6 is controlled based on a signal output from the turning-side ECU 52.

  As shown in FIG. 2, the steering-side ECU 51 includes a steering-side microcomputer 61 that outputs a steering-side motor control signal Sms, and a steering-side drive circuit that supplies driving power to the steering-side motor 17 based on the steering-side motor control signal Sms. 62. The steering-side microcomputer 61 detects a steering-side motor current Is that is a phase current value of each phase of the steering-side motor 17 flowing through a connection line 63 between the steering-side drive circuit 62 and the motor coil of each phase of the steering-side motor 17. Current sensor 64 is connected. In FIG. 2, the connection line 63 of each phase and the current sensor 64 of each phase are collectively shown as one for convenience of explanation.

  The turning-side ECU 52 includes a turning-side microcomputer 65 that outputs a turning-side motor control signal Smt, and a turning-side drive circuit 66 that supplies driving power to the turning-side motor 33 based on the turning-side motor control signal Smt. And The turning-side microcomputer 65 includes, on the turning-side microcomputer 33, a current value of each phase of the turning-side motor 33 flowing through the connection line 67 between the turning-side drive circuit 66 and the motor coil of each phase of the turning-side motor 33. A current sensor 68 for detecting the motor current It is connected. In FIG. 2, the connection line 67 of each phase and the current sensor 68 of each phase are collectively shown as one for convenience of explanation.

  The clutch ECU 53 includes a clutch microcomputer 71 that outputs a clutch control signal Scl, and a clutch drive circuit 72 that supplies drive power to the electromagnetic clutch 6 based on the clutch control signal Scl. A current sensor 74 that detects a clutch current Ic flowing through a connection line 73 between the clutch drive circuit 72 and the coil 41 of the electromagnetic clutch 6 is connected to the clutch microcomputer 71.

  A well-known three-phase inverter having a plurality of switching elements (for example, FETs) is adopted as each of the steering-side drive circuit 62 and the steered-side drive circuit 66 of the present embodiment. A known drive circuit having the following is employed. The steering-side motor control signal Sms and the turning-side motor control signal Smt are gate on / off signals that specify the on / off state of each switching element. Then, the steering-side motor control signal Sms is output to the steering-side drive circuit 62 and the steering-side motor control signal Smt is output to the steering-side drive circuit 66, so that the steering-side motor 17 and the steering-side motor 33 are output. Are supplied with drive power according to the motor control signals Sms and Smt, respectively, and the operations of the steering actuator 16 and the turning actuator 31 are controlled. The operation of the electromagnetic clutch 6 is controlled by outputting the clutch control signal Scl to the clutch drive circuit 72.

  Here, the steering device 2 is normally set in the SBW mode. At this time, the steering microcomputer 61 determines the load condition of the steering motor 17 based on the steering motor current Is while controlling the operation of the steering motor 17. Then, when the load on the steering side motor 17 becomes large, the switching signal Sch1 for setting the EPS mode is output to the steering side ECU 52 and the clutch ECU 53, and the steering side motor 17 is stopped. In the SBW mode, the turning-side microcomputer 65 determines the load condition of the turning-side motor 33 based on the turning-side motor current It while controlling the operation of the turning-side motor 33. Then, when the load on the steering-side motor 33 is increased, a switching signal Sch2 for setting the EPS mode in which the electromagnetic clutch 6 is engaged is output to the steering-side ECU 51 and the clutch ECU 53, and the steering-side motor 33 is stopped. . In the present embodiment, both when the load on the steering-side motor 17 is increased to enter the EPS mode, and when the load on the steering-side motor 33 is increased and the EPS mode is entered, the electromagnetic force is increased after a predetermined protection period has elapsed. The clutch 6 is released and returns to the SBW mode, and the steering microcomputer 61 and the turning microcomputer 65 operate in the SBW mode. Note that the predetermined protection period is a period until the temperatures of the steering-side motor 17 and the turning-side motor 33 are sufficiently reduced in consideration of heat radiation characteristics and the like, and is set in advance based on experiments and the like.

  More specifically, the steering-side microcomputer 61 receives the vehicle speed SPD, the steering torque Th, the rotation angle θs, the steering-side motor current Is, and the switching signal Sch2. Then, in the SBW mode, the steering-side microcomputer 61 outputs a steering-side motor control signal Sms for applying a steering reaction force based on each input state quantity. On the other hand, when the switching signal Sch2 is input and the mode is switched to the EPS mode, the steering-side microcomputer 61 outputs a steering-side motor control signal for providing an assist force to assist the driver in steering based on the input state quantities. Outputs Sms.

  The turning-side microcomputer 65 receives the vehicle speed SPD, the steering torque Th, the rotation angle θt, the turning-side motor current It, the switching signal Sch1, and a target steering angle θh * described later. Then, in the SBW mode, the turning-side microcomputer 65 outputs a turning-side motor control signal Smt for applying a turning force based on each input state quantity. On the other hand, when the switching signal Sch1 is input and the mode is switched to the EPS mode, the turning-side microcomputer 65 outputs a turning-side motor control signal Smt for applying an assist force based on the input state quantities.

  Switching signals Sch1, Sch2 are input to the clutch microcomputer 71. Then, when the switching signal Sch1 or the switching signal Sch2 is input, the clutch microcomputer 71 outputs a clutch control signal Scl for bringing the electromagnetic clutch 6 into an engaged state, thereby setting the EPS mode. Then, when a predetermined protection period has elapsed since the input of the switching signal Sch1 or the switching signal Sch2, the clutch microcomputer 71 outputs a clutch control signal Scl for disengaging the electromagnetic clutch 6 to switch to the SBW mode.

Next, the configurations of the steering microcomputer 61 and the turning microcomputer 65 in the SBW mode will be described.
As shown in FIG. 3, the steering-side microcomputer 61 receives the vehicle speed SPD, the steering torque Th, the rotation angle θs, the steering-side motor current Is, and the switching signal Sch2. Then, the steering-side microcomputer 61 generates and outputs a steering-side motor control signal Sms based on each of these state quantities.

  Specifically, in the SBW mode, the steering-side microcomputer 61 calculates the steering angle θh of the steering wheel 11 based on the rotation angle θs of the steering-side motor 17, and the force for rotating the steering wheel 11. An input torque basic component calculation unit 82 for calculating the input torque basic component Tb * is provided. Further, the steering microcomputer 61 includes a target steering angle calculation unit 83 that calculates a target steering angle θh * based on the steering torque Th, the vehicle speed SPD, and the input torque basic component Tb *, and a steering angle θh and a target steering angle θh *. A steering-side current command value calculation unit 84 that calculates a steering-side current command value Is * corresponding to the target reaction force torque. Further, the steering-side microcomputer 61 includes a steering-side motor control signal output unit 85 that outputs a steering-side motor control signal Sms by executing current feedback control that causes the steering-side motor current Is to follow the steering-side current command value Is *. I have.

  The steering angle calculator 81 converts the input rotation angle θs into an absolute angle including a range exceeding 360 ° by counting the number of rotations of the steering motor 17 from the steering neutral position, for example, and acquires the rotation angle θs. Then, the steering angle calculation unit 81 calculates the steering angle θh by multiplying the rotation angle converted into the absolute angle by a conversion coefficient Ks based on the rotation speed ratio of the steering-side reduction gear 18. The steering angle θh calculated in this manner is output to the subtractor 86.

  The steering torque Th is input to the input torque basic component calculation unit 82. The input torque basic component calculator 82 calculates an input torque basic component (reaction basic component) Tb * having a larger absolute value as the absolute value of the steering torque Th is larger. The input torque basic component Tb * calculated in this way is output to the target steering angle calculation unit 83 and the steering current command value calculation unit 84.

  The target steering angle calculation unit 83 receives the steering torque Th, the vehicle speed SPD, and the input torque basic component Tb *. The target steering angle calculation unit 83 calculates the target steering angle θh * by using a model formula relating the input torque, which is a value obtained by adding the steering torque Th to the input torque basic component Tb *, to the target steering angle θh *. I do. As a model formula, for example, in a case where the steering wheel 11 and the steered wheels 4 are mechanically connected, the relationship between the torque acting on the rotating shaft which can be converted into the steered angle of the steered wheels 4 and the rotation angle is determined. Can be used. The target steering angle θh * calculated in this manner is output to the subtractor 86 and the turning microcomputer 65.

  The steering-side current command value calculation unit 84 receives, in addition to the input torque basic component Tb *, an angle deviation Δθs obtained by subtracting the steering angle θh from the target steering angle θh * in the subtractor 86. Based on the angle deviation Δθs, the steering-side current command value calculation unit 84 calculates a basic reaction that is the basis of the steering reaction force applied by the steering-side motor 17 as a control amount for feedback-controlling the steering angle θh to the target steering angle θh *. Calculate the force torque. Subsequently, the steering-side current command value calculation unit 84 adds the input torque basic component Tb * to the basic reaction force torque to calculate a target reaction force torque serving as a target value of the steering reaction force applied by the steering-side motor 17. Calculate. Then, the steering-side current command value calculator 84 calculates the steering-side current command value Is * based on the target reaction torque. Specifically, the steering-side current command value calculation unit 84 calculates the steering-side current command value Is * having a larger absolute value as the absolute value of the target reaction torque increases.

  The rotation angle θs and the steering motor current Is are input to the steering motor control signal output unit 85 in addition to the steering current command value Is *. In the present embodiment, the current command values on the d-axis and the q-axis in the d / q coordinate system are converted to the actual current values on the d-axis and the q-axis obtained by d / q conversion of the steering-side motor current Is in the orthogonal coordinate system. , The current feedback control is executed, but in this specification, for convenience of description, the coordinate system conversion is omitted.

  The steering-side motor control signal output unit 85 of this embodiment calculates a steering-side voltage command value Vs * by executing PI (proportional-integral) control as current feedback control, and calculates the steering-side voltage command value Vs *. And outputs a steering-side motor control signal Sms.

  Specifically, the steering-side motor control signal output unit 85 includes a subtractor 91 to which the steering-side current command value Is * and the steering-side motor current Is are input. The steering-side motor control signal output unit 85 calculates the current deviation ΔIs by subtracting the steering-side motor current Is from the steering-side current command value Is * in the subtractor 91. The steering-side motor control signal output unit 85 includes a steering-side proportional unit 92 and a steering-side integrator 93.

  The open proportional gain Gpso is set in the steering-side proportional unit 92 as the proportional gain Gps in the SBW mode, and the open-time integral gain Giso is set in the steering-side integrator 93 as the integral gain Gis in the SBW mode. I have. The steering side proportional unit 92 receives the current deviation ΔIs as it is, and the steering side proportional unit 92 outputs to the adder 94 a value obtained by multiplying the current deviation ΔIs by the open-time proportional gain Gpso. On the other hand, a value obtained by integrating the current deviation ΔIs is input to the steering-side integrator 93, and the steering-side integrator 93 outputs to the adder 94 a value obtained by multiplying the integrated value of the current deviation ΔIs by the open-time integration gain Giso. . The steering-side motor control signal output unit 85 outputs a value obtained by adding the output value from the steering-side proportional unit 92 and the output value from the steering-side integrator 93 in the adder 94 as the steering-side voltage command value Vs *. Output to the generation unit 95. The control signal generation unit 95 generates a steering-side motor control signal Sms having a duty ratio based on the steering-side voltage command value Vs *, and outputs it to the steering-side drive circuit 62 (see FIG. 2). As a result, the driving power corresponding to the steering-side motor control signal Sms is output to the steering-side motor 17, and its operation is controlled.

  Further, the steering-side microcomputer 61 includes a steering-side motor load determination unit 87. The steering-side motor current Is is input to the steering-side motor load determination unit 87. Then, the steering-side motor load determination unit 87 determines the load state of the steering-side motor 17 based on the steering-side motor current Is. Specifically, the steering-side motor load determination unit 87 of the present embodiment determines that the load on the steering-side motor 17 is large when the absolute value of the steering-side motor current Is is equal to or greater than the predetermined current value for a predetermined time or more. And outputs the switching signal Sch1 to the turning microcomputer 65 and the clutch microcomputer 71 (see FIG. 2). The predetermined current value is, for example, a large value capable of smoothly turning the steered wheel 4 unless it hits an obstacle or the like, and is determined in advance by experiments or the like. The predetermined time is a time during which the steering-side motor 17 may be overheated when a current equal to or greater than the predetermined current value is continuously supplied to the steering-side motor 17, and is set in advance by experiments or the like.

Next, the turning-side microcomputer 65 will be described.
The turning-side microcomputer 65 receives the rotation angle θt, the target steering angle θh *, the turning-side motor current It, and the switching signal Sch1. Then, the turning-side microcomputer 65 generates and outputs a turning-side motor control signal Smt based on each of these state quantities.

  More specifically, the turning-side microcomputer 65 in the SBW mode includes a turning-related angle calculation unit 101 that calculates a turning-corresponding angle θp corresponding to the rotation angle (pinion angle) of the first pinion shaft 21. Further, the turning-side microcomputer 65 calculates a turning-side current command value It * corresponding to the target turning torque based on the turning angle θp and the target steering angle θh *. It has. Further, the turning-side microcomputer 65 outputs a turning-side motor control signal Smt by executing current feedback control for causing the turning-side motor current It to follow the turning-side current command value It *. A section 103 is provided. In the steering device 2 of the present embodiment, the steering angle ratio, which is the ratio between the steering angle θh and the steering angle θp, is set to be constant, and the target steering angle is equal to the target steering angle θh *. .

  The turning angle calculation unit 101 obtains the input rotation angle θt by converting the rotation angle of the turning-side motor 33 from the neutral position where the vehicle goes straight, for example, to the absolute angle by counting. Then, the turning-related angle calculation unit 101 converts the rotation angle converted into the absolute angle based on the rotation speed ratio of the turning-side reduction gear 34 and the rotation speed ratio of the first and second rack and pinion mechanisms 25 and 35. The steering angle θp is calculated by multiplying the coefficient Kt. That is, the steering angle θp corresponds to the steering angle θh of the steering wheel 11 on the assumption that the first pinion shaft 21 is connected to the steering shaft 12. The steering angle θp thus calculated is output to the subtractor 104. The subtractor 104 receives the target steering angle θh * (target steering corresponding angle) in addition to the steering corresponding angle θp.

  The turning-side current command value calculation unit 102 receives an angle deviation Δθp obtained by subtracting the turning angle θp from the target steering angle θh * (target turning angle) in the subtractor 104. Based on the angle deviation Δθp, the turning-side current command value calculation unit 102 calculates the steering force applied by the turning-side motor 33 as a control amount for feedback-controlling the turning-corresponding angle θp to the target steering angle θh *. A target steering torque that is a target value is calculated. Then, the turning-side current command value calculation unit 102 calculates the turning-side current command value It * based on the target turning torque. Specifically, the turning-side current command value calculation unit 102 calculates a turning-side current command value It * having a larger absolute value as the absolute value of the target turning torque is larger.

  The turning angle θt and the turning side motor current It are input to the turning side motor control signal output unit 103 in addition to the turning side current command value It *. The turning-side motor control signal output unit 103 of the present embodiment calculates the turning-side voltage command value Vt * by executing PI control as current feedback control, and based on the turning-side voltage command value Vt *. A steering-side motor control signal Smt is output.

  Specifically, the turning-side motor control signal output unit 103 includes a subtractor 111 to which the turning-side current command value It * and the turning-side motor current It are input. The turning-side motor control signal output unit 103 calculates a current deviation ΔIt by subtracting the turning-side motor current It from the turning-side current command value It * in the subtractor 111. The turning-side motor control signal output unit 103 includes a turning-side proportional unit 112 and a turning-side integrator 113.

  The open-side proportional gain Gpto is set in the turning-side proportional unit 112 as the proportional gain Gpt in the SBW mode, and the open-time integral gain Gito is set in the turning-side integrator 113 as the integral gain Git in the SBW mode. Have been. Then, the current deviation ΔIt is directly input to the turning-side proportional unit 112, and the turning-side proportional unit 112 outputs to the adder 114 a value obtained by multiplying the current deviation ΔIt by the open-time proportional gain Gpto. On the other hand, a value obtained by integrating the current deviation ΔIt is input to the turning-side integrator 113, and the turning-side integrator 113 adds a value obtained by multiplying the integrated value of the current deviation ΔIt by the open-time integration gain Gito to the adder 114. Output to The turning-side motor control signal output unit 103 uses an adder 114 to add a value obtained by adding the output value from the turning-side proportional unit 112 and the output value from the turning-side integrator 113 to the turning-side voltage command value Vt. It is output to the control signal generator 115 as *. The control signal generation unit 115 generates a turning-side motor control signal Smt having a duty ratio based on the turning-side voltage command value Vt *, and outputs it to the turning-side drive circuit 66 (see FIG. 2). As a result, the driving power according to the turning-side motor control signal Smt is output to the turning-side motor 33, and its operation is controlled.

  The turning microcomputer 65 includes a turning motor load determination unit 105. The turning-side motor current It is input to the turning-side motor load determination unit 105. Then, the turning-side motor load determination unit 105 determines the load condition of the turning-side motor 33 in the same manner as the steering-side motor load determination unit 87 based on the turning-side motor current It, and steers the switching signal Sch2. It is output to the side microcomputer 61 and the clutch microcomputer 71 (see FIG. 2).

Next, the configurations of the steering microcomputer 61 and the turning microcomputer 65 in the EPS mode will be described.
As shown in FIG. 4, the steering-side microcomputer 61 executes control in the EPS mode when the switching signal Sch2 is input. Specifically, the steering-side microcomputer 61 receives the vehicle speed SPD, the steering torque Th, the rotation angle θs, and the steering-side motor current Is. Then, the steering-side microcomputer 61 generates and outputs a steering-side motor control signal Sms based on each of these state quantities.

  More specifically, the steering-side microcomputer 61 in the EPS mode calculates a steering-side current command value calculation unit 121 that calculates the steering-side current command value Is *, and a current that causes the steering-side motor current Is to follow the steering-side current command value Is *. A steering-side motor control signal output unit 122 that outputs a steering-side motor control signal Sms by executing the feedback control.

  The vehicle speed SPD and the steering torque Th are input to the steering-side current command value calculation unit 121. The steering-side current command value calculation unit 121 calculates the steering-side current command value Is * based on these state quantities. Specifically, the steering-side current command value calculation unit 121 calculates the steering-side current command value Is * having a larger absolute value as the absolute value of the steering torque Th is larger and the vehicle speed SPD is larger.

  The rotation angle θs and the steering-side motor current Is are input to the steering-side motor control signal output unit 122 in addition to the steering-side current command value Is *. The steering-side motor control signal output unit 122 includes a subtractor 131, a proportional unit 132, an integrator 133, an adder 134, and a control signal generation unit 135. The steering-side motor control signal output unit 85 in the SBW mode (see FIG. As in the case of 3), the steering-side motor control signal Sms is output by executing the PI control. However, the proportionality device 132 is set with the engagement-time proportional gain Gpse as the proportional gain Gps in the EPS mode, and the integrator 133 is set with the engagement-time integral gain Gise as the integration gain Gis in the EPS mode. I have. It should be noted that the on-engagement proportional gain Gpse and the on-engagement integral gain Gise may be different from or the same as the above-mentioned disengagement proportional gain Gpso and disengagement integral gain Giso. When the steering-side motor control signal Sms is output from the steering-side motor control signal output unit 122 to the steering-side drive circuit 62 (see FIG. 2), the drive power corresponding to the steering-side motor control signal Sms is output. 17 and its operation is controlled.

  The turning-side microcomputer 65 executes control in the EPS mode when the switching signal Sch1 is input. Specifically, the turning-side microcomputer 65 in the EPS mode is configured similarly to the steering-side microcomputer 61 in the EPS mode. In FIG. 4, the state quantities calculated by the turning-side microcomputer 65 are shown in parentheses. However, in the proportional unit 132, the on-engagement proportional gain Gpte is set as the proportional gain Gpt in the EPS mode, and in the integrator 133, the on-engagement integral gain Gite is set as the integral gain Git in the EPS mode. I have. It should be noted that the on-engagement proportional gain Gpte and the on-engagement integral gain Gite may be different values or the same values as the above-mentioned disengagement proportional gain Gpto and disengagement integral gain Gito. Then, the turning-side motor control signal Smt is output from the turning-side motor control signal output unit to the turning-side drive circuit 66 (see FIG. 2), so that the driving power according to the turning-side motor control signal Smt is generated. The output is output to the steering-side motor 33, and its operation is controlled.

Next, the configuration of the clutch microcomputer 71 will be described.
As shown in FIG. 5, the switching signals Sch1, Sch2 and the clutch current Ic are input to the clutch microcomputer 71. Then, the clutch microcomputer 71 generates and outputs a clutch control signal Scl based on each of these state quantities.

  More specifically, the clutch microcomputer 71 in the EPS mode executes the clutch current command value calculation unit 141 for calculating the clutch current command value Ic * and the current feedback control for causing the clutch current Ic to follow the clutch current command value Ic *. A clutch control signal output unit 142 for outputting the control signal Scl.

  The switching signals Sch1 and Sch2 are input to the clutch current command value calculation unit 141. When either of the switching signals Sch1 and Sch2 is input, the clutch current command value calculation unit 141 changes the clutch current command value Ic * to a predetermined engagement current in order to bring the electromagnetic clutch 6 into the engaged state. Ice. Further, the clutch current command value calculation unit 141 sets the clutch current command value Ic * in advance so that the electromagnetic clutch 6 is released after a predetermined protection period has elapsed after either of the switching signals Sch1 and Sch2 is input. It is assumed that the attraction current Icd is obtained. Then, the clutch current command value calculation unit 141 sets the clutch current command value Ic * to a preset holding current Ick after a predetermined suction time has elapsed since the clutch current command value Ic * was set to the suction current Icd.

  The engagement current Ice is a current value at which an electromagnetic attraction force does not substantially occur in the coil 41, and is set to, for example, zero. The attraction current Icd is a current value that can surely separate the input side plate 42 and the output side plate 43 engaged with each other, and is set in advance by an experiment or the like. The holding current Ick is a current value that can be held while keeping the input side plate 42 and the output side plate 43 separated from each other, is smaller than the attraction current Icd, and is set in advance by an experiment or the like.

  The clutch control signal output unit 142 receives the clutch current Ic in addition to the clutch current command value Ic *. The clutch control signal output unit 142 of the present embodiment calculates a clutch voltage command value Vc * by executing PI control as current feedback control, and outputs a clutch control signal Scl based on the clutch voltage command value Vc *. .

  Specifically, the clutch control signal output unit 142 includes a subtractor 151 to which the clutch current command value Ic * and the clutch current Ic are input. The clutch control signal output unit 142 calculates the current deviation ΔIc by subtracting the clutch current Ic from the clutch current command value Ic * in the subtractor 151. In addition, the clutch control signal output unit 142 includes a clutch proportional unit 152 and a clutch integrator 153. The clutch proportional unit 152 receives the current deviation ΔIc and the switching signals Sch1 and Sch2, and the clutch integrator 153 receives the integrated value of the current deviation ΔIc and the switching signals Sch1 and Sch2.

  In the clutch proportional unit 152, the on-engagement proportional gain Gpce is set as the proportional gain Gpc in the EPS mode, and the disengagement proportional gain Gpco is set as the proportional gain Gpc in the SBW mode. The clutch proportional unit 152 uses the on-engagement proportional gain Gpce during a predetermined protection period after either of the switching signals Sch1 and Sch2 is input, and uses the on-opening proportional gain Gpco during the other periods. Similarly, in the clutch integrator 153, the integral gain Gice during engagement is set as the integral gain Gic in the EPS mode, and the integral gain Gico during release is set as the integral gain Gic in the SBW mode. Then, the clutch integrator 153 uses the integrated gain Gice during engagement for a predetermined protection period after either of the switching signals Sch1 and Sch2 is input, and uses the integrated gain Gico during disengagement during other periods. In the present embodiment, the on-engagement proportional gain Gpce and the on-engagement integral gain Gice are set to small values at which the followability of the clutch current Ic to the clutch current command value Ic * decreases. In addition, the release-time proportional gain Gpco and the release-time integral gain Gico are set to large values that increase the followability of the clutch current Ic with the clutch current command value Ic *.

  It should be noted that the values of the on-engagement proportional gain Gpce, on-release proportional gain Gpco, on-engagement integral gain Gice, and on-release integral gain Gico can be changed as appropriate. For example, the on-engagement proportional gain Gpce and the on-engagement integral gain Gice may be set to large values, and the disengagement proportional gain Gpco and the on-release integral gain Gico may be set to large values. Also, for example, the engagement-time proportional gain Gpce and the engagement-time integral gain Gice may be set to large values, and the release-time proportional gain Gpco and the release-time integral gain Gico may be set to small values. Further, for example, the engagement-time proportional gain Gpce and the engagement-time integral gain Gice may be set to small values, and the release-time proportional gain Gpco and the release-time integral gain Gico may be set to small values.

  Then, in the EPS mode, the clutch proportional unit 152 outputs a value obtained by multiplying the current deviation ΔIc by the on-engagement proportional gain Gpce to the adder 154, and the clutch integrator 153 outputs the value when the integrated value of the current deviation ΔIc is engaged. The value multiplied by the integral gain Gice is output to the adder 154. On the other hand, in the SBW mode, the clutch proportional unit 152 outputs a value obtained by multiplying the current deviation ΔIc by the release proportional gain Gpco to the adder 154, and the clutch integrator 153 outputs the integrated value of the current deviation ΔIc to the release integral gain. The value multiplied by Gico is output to the adder 154. The clutch control signal output unit 142 outputs a value obtained by adding the output value from the clutch integrator 153 and the output value from the clutch integrator 153 in the adder 154 to the control signal generation unit 155 as a clutch voltage command value Vc *. I do. The control signal generator 155 generates a clutch control signal Scl having a duty ratio based on the clutch voltage command value Vc *, and outputs it to the clutch drive circuit 72 (see FIG. 2). As a result, drive power corresponding to the clutch control signal Scl is output to the electromagnetic clutch 6, and its operation is controlled.

Next, an operation of switching the engaged / disengaged state of the electromagnetic clutch 6 will be described.
For example, it is assumed that the electromagnetic clutch 6 switches from the engaged state to the released state, and then switches to the engaged state again. At this time, the clutch current command value Ic * becomes the engagement current Ice when the electromagnetic clutch 6 is engaged, as shown in FIG. Subsequently, when the electromagnetic clutch 6 enters the disengaged state after the elapse of the predetermined protection period, the current changes to the attraction current Icd, and after the elapse of the predetermined attraction time, the clutch current command value Ic * becomes the holding current Ick. Thereafter, when the load on the steering-side motor 17 or the turning-side motor 33 increases and the electromagnetic clutch 6 switches to the engaged state, the clutch current command value Ic * becomes the engagement current Ice.

  Here, when the electromagnetic clutch 6 switches from the engaged state to the released state, the on-engagement proportional gain Gpce and the on-engagement integral gain Gice of the clutch control signal output unit 142 of the present embodiment are set to small values. The response of the clutch current Ic to a change in the clutch current command value Ic * is low and changes gently. Thereby, since the electromagnetic clutch 6 is slowly switched from the engaged state to the released state, generation of abnormal noise or the like when the electromagnetic clutch 6 is switched from the engaged state to the released state is suppressed. Further, when the electromagnetic clutch 6 is switched from the disengaged state to the engaged state, since the disengagement proportional gain Gpco and the disengagement integral gain Gico of the clutch control signal output unit 142 of this embodiment are set to large values, the clutch current The responsiveness of the clutch current Ic to a change in the command value Ic * is high and changes sharply. As a result, the electromagnetic clutch 6 is quickly switched from the disengaged state to the engaged state, so that, for example, the steering-side motor 17 or the turning-side motor 33 with a large load is stopped immediately.

  When the on-engagement proportional gain Gpce and the on-engagement integral gain Gice are set to large values, the responsiveness of the clutch current Ic to a change in the clutch current command value Ic * is high and changes sharply. Thus, for example, the mode can be quickly switched from the SBW mode to the EPS mode. When the open-time proportional gain Gpco and the open-time integral gain Gico are set to small values, the responsiveness of the clutch current Ic to a change in the clutch current command value Ic * is low and changes gently. When the electromagnetic clutch 6 switches from the disengaged state to the engaged state, generation of abnormal noise and the like is suppressed.

The operation and effect of the present embodiment will be described.
(1) Regarding the proportional gain Gpc and the integral gain Gic used for the current feedback control of the electromagnetic clutch 6, the on-engagement proportional gain Gpce and the on-engagement integral gain Gice used when switching from the engaged state to the released state, and from the released state The open-time proportional gain Gpco and the open-time integral gain Gico used for switching to the engaged state were set. Therefore, it is possible to suitably adjust the manner of switching between the engaged and released states of the electromagnetic clutch.

  (2) Regarding the proportional gain Gps and the integral gain Gis used for the current feedback control of the steering side motor 17, the engaged proportional gain Gpse and the integrated gain Gise used in the engaged state, and the released proportional gain Gise used in the released state. Gpso and the open-time integral gain Giso were set respectively. Therefore, the operation of the steering side motor 17 can be suitably controlled according to whether the electromagnetic clutch 6 is in the engaged state or the released state.

  (3) Regarding the proportional gain Gpt and the integral gain Git used for the current feedback control of the steered motor 33, the engaged proportional gain Gpte and the integrated gain Gite used in the engaged state, and the released proportional used in the released state. The gain Gpto and the open-time integral gain Gito were set respectively. Therefore, the operation of the steered motor 33 can be suitably controlled depending on whether the electromagnetic clutch 6 is in the engaged state or the released state.

This embodiment can be implemented with the following modifications. The present embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.
In the above embodiment, the load state of the steering motor 17 or the turning motor 33 is determined based on the steering motor current Is or the turning motor current It, and the SBW mode is changed to the EPS mode according to the determination result. Switched. However, the present invention is not limited to this. For example, the temperature of the steering-side motor 17 or the turning-side motor 33 may be detected, and the SBW mode may be switched to the EPS mode in accordance with the detected temperature. Can be changed as appropriate.

  In the above-described embodiment, the mode is switched to the EPS mode after a predetermined protection period has elapsed after the SBW mode. However, the present invention is not limited to this. For example, the temperature of the steering motor 17 or the turning motor 33 is equal to or less than a preset threshold. May be switched from the SBW mode to the EPS mode, and the mode of switching from the SBW mode to the EPS mode can be changed as appropriate.

  In the above embodiment, the same gain is used as the control gain used for the current feedback control of the turning-side motor 33 without distinguishing the engaged gain used in the engaged state and the released gain used in the released state. May be used.

  In the above embodiment, the same gain is used as the control gain used for the current feedback control of the steering side motor 17 without distinguishing the engaged gain used in the engaged state and the released gain used in the released state. May be.

  In the above embodiment, the clutch control signal output unit 142 executes the PI control as the current feedback control. However, the present invention is not limited to this. For example, a differential element obtained by multiplying a differential value of the current deviation ΔIc by a differential gain is added. PID (proportional-integral-derivative) control may be executed, and the mode of current feedback control can be changed as appropriate. Similarly, the steering-side motor control signal output units 85 and 122 and the steering-side motor control signal output unit 103 may execute, for example, PID control as current feedback control.

  In the above-described embodiment, a so-called normally open type electromagnetic clutch which is opened when the coil 41 is not energized and is engaged when the coil 41 is energized may be employed as the electromagnetic clutch 6.

  In the above-described embodiment, a clutch control unit that outputs the clutch control signal Scl, a steering control unit that outputs the steering motor control signal Sms, and a steering control unit that outputs the steering motor control signal Smt are provided. The steering control device 1 may be configured by a single ECU.

Next, technical ideas that can be grasped from the above embodiments and modified examples will be additionally described below.
(A) The steering control device, wherein the control gain used for the current feedback control of the electromagnetic clutch is a proportional gain and an integral gain.

(B) The steering control device, wherein the control gain used for the current feedback control of the steering side motor is a proportional gain and an integral gain.
(C) The steering control device, wherein the control gain used for the current feedback control of the steered motor is a proportional gain and an integral gain.

  DESCRIPTION OF SYMBOLS 1 ... Steering control device, 2 ... Steering device, 3 ... Steering part, 4 ... Steering wheel, 5 ... Steering part, 6 ... Electromagnetic clutch, 17 ... Steering side motor, 31 ... Steering side actuator, 51 ... Steering side ECU , 52: turning side ECU, 53: clutch ECU, 61: steering side microcomputer (steering side control unit), 65: turning side microcomputer (turning side control unit), 71: clutch microcomputer (clutch control unit), 84 , 121: Steering-side current command value calculation unit, 85, 122: Steering-side motor control signal output unit, 92: Steering-side proportional unit, 93: Steering-side integrator, 102: Steering-side current command value calculation unit, 103 ... Turning-side motor control signal output unit, 112: turning-side proportional unit, 113: turning-side integrator, 132: proportional unit, 133: integrator, 141: clutch current command value calculating unit, 142: clutch control signal output Part, 152 ... clutch proportional unit 153: clutch integrator, Gic, Gis, Git: integral gain, Gice, Gise, Gite: engaged integral gain, Gico, Giso, Gito: released integral gain, Gpc, Gps, Gpt: proportional gain, Gpce, Gpse , Gpte: proportional gain at engagement, Gpco, Gpso, Gpto: proportional gain at release, Ic: clutch current, Ic *: clutch current command value, It *: steering current command value, Is: steering motor current, Is *: steering-side current command value, It: turning-side motor current, Sch1, Sch2: switching signal, Scl: clutch control signal, Sms: steering-side motor control signal, Smt: turning-side motor control signal, ΔIc, ΔIs , ΔIt... Current deviation.

Claims (3)

A steering unit including: a steering unit; a steering unit that steers a steered wheel in accordance with steering input to the steering unit; and an electromagnetic clutch that can mechanically connect and disconnect the steering unit and the steering unit. The device to be controlled,
By supplying a drive current to the electromagnetic clutch, an engagement state in which the electromagnetic clutch transmits power from the steering section to the steering section, and an open state in which power transmission from the steering section to the steering section is interrupted. Equipped with a clutch control unit for switching between
The clutch control unit executes current feedback control for causing a clutch current that is an actual drive current to follow a clutch current command value that is a target value of a drive current supplied to the electromagnetic clutch,
The clutch control unit includes, as a control gain used for current feedback control of the electromagnetic clutch, a gain at the time of engagement used when switching from the engaged state to the released state, and switching from the released state to the engaged state. A steering control device in which the open gain used in each case is set. The steering control device according to claim 1,
A steering-side control unit that controls the operation of a steering-side motor capable of providing a steering reaction force against steering input to the steering unit;
The steering-side control unit executes current feedback control that causes a steering-side motor current that is an actual drive current to follow a steering-side current command value that is a target value of a drive current supplied to the steering-side motor, ,
In the steering-side control unit, a control gain used for the current feedback control of the steering-side motor is set to a gain at the time of engagement used in the engagement state and a gain at the time of release used in the release state. Control device. The steering control device according to claim 1 or 2,
A turning-side control unit that controls the operation of a turning-side motor that can apply a turning force to turn the steered wheels to the turning unit;
The turning-side control unit executes a current feedback control that causes a turning-side motor current, which is an actual driving current, to follow a turning-side current command value that is a target value of the driving current supplied to the turning-side motor. Thing,
In the turning-side control unit, a gain at the time of engagement used in the engaged state and a gain at the time of opening used in the released state are set as control gains used for current feedback control of the turning-side motor. Steering control device.