JP2019130957A - Steer-by-wire type steering device - Google Patents

Abstract

To provide a steer-by-wire type steering device capable of facilitating releasing of steering regulation of a steering section when the steering regulation of the steering section is released after a starting switch of a vehicle drive source is on.SOLUTION: A steer-by-wire type steering device, having a structure in which a steering section and a turning section are not mechanically connected, includes: a regulation section for regulating steering of the steering section when an IGSW is off; a steering side motor 14 for applying a steering reaction against steering of the steering section; a reaction control section for increasing a steering reaction; a steering side control section 61 for controlling an operation of the steering side motor 14 so that steering reaction occurs; and a determination section 69 for determining whether or not regulation of the steering of the steering section by the regulation section is under a releasing state. The steering side control section 61, with the IGSW on and regulation of the steering of the steering section by the regulation section released, executes torque adjustment processing when the determination section 69 determines it not to be under a releasing state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a steer-by-wire type steering apparatus.

  Conventionally, it has a structure in which power transmission between a steering unit connected to a steering wheel steered by a driver and a steering unit that steers steered wheels according to steering of the steering unit by the driver is separated. Steer-by-wire steering devices (Patent Documents 1 and 2) are known.

  The steer-by-wire type steering device described in Patent Document 1 adds an end contact reaction force to the steering reaction force applied to the steering unit in accordance with the arrival of the steered wheels at the maximum steered position. The impact is suppressed.

  Further, in the steer-by-wire type steering device described in Patent Document 2, when the start switch of the vehicle drive source is in an OFF state, the steering unit and the steered unit are fastened by a clutch to regulate the steering of the steering unit. ing.

Japanese Patent Laying-Open No. 2006-164017 JP 2014-133534 A

  By the way, in the steer-by-wire steering device described above, the start switch may be turned off in a state where the steered wheels have reached the maximum steered position. In this state, when the start switch is turned on, reaction torque may be applied before the clutch is released. For this reason, an end contact reaction force acts on the clutch, and there may be a situation where the steering restriction of the steering unit is not released. Such a problem is a steer-by-wire that has a structure in which the steering unit and the steered unit are separated, and is equipped with a regulating unit that can be switched between a locked state and a unlocked state of the steering unit. This also occurs in the type steering device.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a steer-by-wire steering device that facilitates releasing the steering restriction of the steering unit when the steering restriction of the steering unit is released after the start switch of the vehicle drive source is turned on. It is to be.

The steer-by-wire type steering device that can achieve the above object has a structure in which a steering unit coupled to a steering wheel and a steered unit that steers steered wheels according to the steering of the steering unit can be mechanically coupled, or A steer-by-wire steering device having a structure that is separated and not mechanically connected is assumed. A regulating unit that regulates steering of the steering unit when a start switch of a vehicle drive source is in an off state, a motor that applies a steering reaction force against the steering of the steering unit to the steering unit, and the steering reaction force A steering-side control unit that controls the operation of the motor so that the steering is generated, and the steering-side control unit is configured such that a steering angle of the steering unit is set corresponding to a turning limit of the steered wheels. A reaction force control unit that increases the steering reaction force so as not to exceed the steering limit of the wheel, and a determination unit that determines whether or not the restriction of steering of the steering unit by the restriction unit is released The steering-side control unit is determined not to be in the release state by the determination unit when the start switch is in an on state and the restriction of steering of the steering unit by the restriction unit is released. The reaction force control Executing the steering torque adjustment process is process of suppressing the increase of the reaction force due.
According to this configuration, an increase in the steering reaction force by the reaction force control unit is suppressed before the steering restriction of the steering unit is released. Therefore, after the start switch of the vehicle drive source is turned on, it becomes easy to release the steering restriction of the steering unit when the steering restriction of the steering unit is released.

  Here, the control for increasing the steering reaction force by the reaction force control unit should be performed when the steering angle of the steering wheel is included in the limit range. Therefore, if the steering angle of the steering wheel is not included in the limit range including the steering limit before the restriction of the steering of the steering unit by the restriction unit is released, the torque adjustment process may not be performed. Good.

  Therefore, the steering side control unit executes the torque adjustment process on the condition that the steering angle when the start switch is switched from the off state to the on state is included in a limit range including the steering limit. Is preferred.

  In addition, the steering-side control unit can control the operation of the motor by the steering-side control unit using the voltage supplied to the steering-side control unit after the start switch is switched from the off state to the on state. It is preferable to execute the torque adjustment process on the condition that the steering angle when the threshold is reached is included in a limit range including the steering limit.

According to this configuration, it is possible to optimize conditions for the steering-side control device to perform the torque adjustment process.
In the steer-by-wire steering apparatus, the steering-side control unit interrupts the torque adjustment process when the determination unit determines that the release state is in effect during the torque adjustment process, It is preferable to gradually increase the steering reaction force by the reaction force control unit.

  In a state where the steering angle of the steering wheel is included in the limit range, in other words, in a state where a condition for executing the control for increasing the steering reaction force by the reaction force control unit is satisfied, When the regulation is released, it is conceivable that the steering reaction force is suddenly increased, so that the driver feels uncomfortable. In that respect, according to the above configuration, even when the regulation of the steering unit by the regulation unit is released and the reaction force control unit increases the steering reaction force, the steering reaction force may increase rapidly. Disappear. Therefore, it is possible to prevent the driver from feeling uncomfortable and to improve the steering feeling of the steering wheel.

  The steer-by-wire steering apparatus further includes a torque detection unit that detects a steering torque that acts on the steering unit, and a steering speed detection unit that detects a steering speed of the steering unit, wherein the determination unit includes the steering unit When the absolute value of the torque is greater than the torque determination value and the absolute value of the steering speed exceeds the speed determination value, it is determined that the steering unit is in the release state, and the absolute value of the steering torque is greater than the torque determination value. It is preferable to determine that the steering unit is not in the released state when the steering speed is large and the absolute value of the steering speed is equal to or less than the speed determination value.

  In the above steer-by-wire type steering device, when the start switch is turned off and torque acts on the restricting portion, the restriction of the steering portion by the restricting portion is released when the start switch is switched from the off state to the on state. However, it may not be released. In this case, torque acting on the steering unit is detected as steering torque by the torque detection unit.

  Therefore, when the determination switch determines that the steering switch is not in the release state when the start switch is switched from the OFF state to the ON state, the steering side control unit approaches the absolute value of the steering torque to “0”. Thus, it is preferable to control the operation of the motor.

  In addition, the steering-side control unit can control the operation of the motor by the steering-side control unit using the voltage supplied to the steering-side control unit after the start switch is switched from the off state to the on state. When the determination unit determines that it is not in the release state when the threshold value is reached, it is preferable to control the operation of the motor so that the absolute value of the steering torque approaches “0”.

According to the steer-by-wire type steering apparatus of the present invention, it becomes easy to release the steering restriction of the steering unit when the steering restriction of the steering unit is released after the start switch of the vehicle drive source is turned on.

(A) is a schematic block diagram of 1st Embodiment of a steer-by-wire type steering apparatus, (b) is a schematic sectional drawing in the locking device of 1st Embodiment. The block diagram of CPU of 1st Embodiment. The block diagram of the target steering angle setting part of CPU of 1st Embodiment. The control flowchart of the steering side control part of CPU of 1st Embodiment. The schematic block diagram of 2nd Embodiment of a steer-by-wire type steering apparatus.

<First Embodiment>
Hereinafter, a first embodiment of the steer-by-wire steering apparatus will be described.
As shown in FIG. 1A, the steer-by-wire steering device 2 includes a steering unit 3 connected to a steering wheel 11, and a steering unit 5 that steers the steered wheels 4 according to the steering of the steering unit 3. And a restricting portion 8 for restricting the steering of the steering portion 3. Further, the steer-by-wire steering device 2 includes a steering control device 1 that controls operations of the steering side actuator 13 provided in the steering unit 3, the steered side actuator 41 provided in the steered unit 5, and the regulating unit 8. The steer-by-wire steering device 2 is a linkless steer-by-wire steering device having a structure in which the steering unit 3 and the steered unit 5 are separated and not mechanically connected.

  The restriction unit 8 controls the steering unit 3 when an ignition switch 9 (hereinafter referred to as “IGSW9”) serving as a start switch of a vehicle drive source provided between the steering control device 1 and the in-vehicle power supply 27 is in an off state. To regulate. The vehicle drive source is, for example, a vehicle engine.

As shown in FIG.1 (b), the control part 8 is provided with the pin member 8a. When the IGSW 9 is in the off state, the restricting portion 8 inserts the pin member 8a into the through hole 12a provided so as to penetrate the inside and outside of the steering shaft 12 based on a command from the steering control device 1. Thereby, the rotation of the steering shaft 12 is restricted, and the steering of the steering unit 3 is restricted. Basically, when the IGSW 9 is switched from the off state to the on state, the restricting portion 8 causes the pin member 8a to be separated from the through hole 12a provided in the steering shaft 12 based on a command from the steering control device 1. . Thereby, the restriction | limiting of rotation of the steering shaft 12 is cancelled | released, and the restriction | limiting of steering of the steering part 3 is cancelled | released. On the other hand, when any abnormality occurs in the steer-by-wire type steering device 2 and the steer-by-wire type control cannot be executed, the regulating unit 8 moves the pin member 8a to the steering shaft 12 based on a command from the steering control device 1, for example. The state of being inserted through the through-hole 12a provided in is maintained. In the present embodiment, the restriction of the steering portion 3 by the restriction portion 8 means that there is a clearance due to tolerance that can be formed between the pin member 8a and the through hole 12a. Also includes a state where it can be rotated.
As shown in FIG. 1A, the steering unit 3 includes a steering shaft 12 to which the steering wheel 11 is fixed so as to be integrally rotatable, and a steering side actuator 13 that applies a steering reaction force to the steering shaft 12. . The steering-side actuator 13 includes a steering-side motor 14 serving as a drive source, and a steering-side speed reducer 15 that decelerates the rotation of the steering-side motor 14 and transmits it to the steering shaft 12.

  A spiral cable device 21 is connected to the steering wheel 11. The spiral cable device 21 is defined by a first housing 22 fixed to the steering wheel 11, a second housing 23 fixed to the vehicle body, a second housing 23, and a first housing 22 and a second housing 23. A cylindrical member 24 accommodated in the space formed, and a spiral cable 25 wound around the cylindrical member 24. The steering shaft 12 is inserted through the cylindrical member 24. The spiral cable 25 is an electrical wiring that connects various switches 26 including a horn switch fixed to the steering wheel 11 and an in-vehicle power source 27 fixed to the vehicle body. The length of the spiral cable 25 is set to be sufficiently longer than the distance between the various switches 26 and the in-vehicle power source 27, and the rotation of the steering wheel 11 is allowed within a range corresponding to the length.

  The steered portion 5 includes a first pinion shaft 31, a rack shaft 32 connected to the first pinion shaft 31, and a rack housing 33 that accommodates the rack shaft 32 in a reciprocating manner. The first pinion shaft 31 and the rack shaft 32 are arranged with a predetermined crossing angle. A first rack and pinion mechanism 34 is configured by meshing the first pinion teeth 31 a formed on the first pinion shaft 31 with the first rack teeth 32 a of the rack shaft 32. The rack shaft 32 is supported by the first rack and pinion mechanism 34 so that one end side in the axial direction can reciprocate. A tie rod 36 is connected to both ends of the rack shaft 32 via a ball joint 35, and a tip of the tie rod 36 is connected to a knuckle (not shown) to which the steered wheels 4 are assembled.

  Further, the steered portion 5 includes a second pinion shaft 42 and a steered side actuator 41 that applies a steered force that steers the steered wheels 4 to the rack shaft 32 via the second pinion shaft 42. Yes. The steered side actuator 41 includes a steered side motor 43 serving as a drive source and a steered side speed reducer 44 that decelerates the rotation of the steered side motor 43 and transmits it to the second pinion shaft 42. The second pinion shaft 42 and the rack shaft 32 are arranged with a predetermined crossing angle. The second rack and pinion mechanism 45 is configured by the engagement of the second pinion teeth 42 a formed on the second pinion shaft 42 and the second rack teeth 32 b formed on the rack shaft 32. The rack shaft 32 is supported by the second rack and pinion mechanism 45 so that the other axial end of the rack shaft 32 can reciprocate.

In the steer-by-wire type steering apparatus 2 configured as described above, the second pinion shaft 42 is rotationally driven by the steered side actuator 41 in accordance with the operation of the steering wheel 11 by the driver, and this rotation is the second rack and pinion mechanism. 45 is converted into a reciprocating motion in the axial direction of the rack shaft 32. As a result, the turning angle of the steered wheels 4 is changed.
The steering control device 1 includes a power supply circuit 6, a central processing unit 7 (hereinafter referred to as “CPU 7”), and a memory (not shown). The power supply circuit 6 adjusts the voltage (for example, 12V) supplied from the vehicle-mounted power supply 27 when the IGSW 9 is switched from the off state to the on state to a voltage value (for example, 5V) that allows the CPU 7 to operate appropriately. In other words, the power supply circuit 6 gradually increases the voltage V supplied from the in-vehicle power supply 27 to the steering control device 1 to a voltage value that allows the CPU 7 to operate appropriately when the IGSW 9 is turned on. When the voltage V supplied from the in-vehicle power supply 27 exceeds a voltage value at which the CPU 7 can operate properly, the steering control device 1 causes the CPU 7 to execute a program stored in the memory every predetermined calculation cycle, thereby Various controls are executed.

  The steering control device 1 is connected to a vehicle speed sensor 51 that detects a vehicle speed SPD of the vehicle and a torque sensor 52 that serves as a torque detection unit that detects a steering torque Trq applied to the steering shaft 12. The torque sensor 52 is provided closer to the steering wheel 11 than the portion of the steering shaft 12 connected to the steering-side speed reducer 15. In addition, a steering-side rotation angle sensor 53 that detects the rotation angle θs of the steering-side motor 14 and a steering-side rotation angle sensor 54 that detects the rotation angle θt of the steering-side motor 43 are connected to the steering control device 1. ing. The steering control device 1 controls the operation of the steering side motor 14 and the steered side motor 43 based on various state quantities of the vehicle speed SPD, the steering torque Trq, and the rotation angles θs and θt. The steering torque Trq and the rotation angles θs and θt are positive values when the steering wheel 11 is steered in one direction (right direction in the present embodiment), and steer in the other direction (left direction in the present embodiment). In this case, it is detected as a negative value.

The electrical configuration of the steering control device 1 will be described focusing on the configuration of the CPU 7.
As shown in FIG. 2, the CPU 7 of the steering control device 1 supplies driving power to the steering side motor 14 based on the steering side control unit 61 that outputs the steering side motor control signal Ms and the steering side motor control signal Ms. And a steering side drive circuit 62. In addition, the steering control device 1 includes a steered side control unit 63 that outputs a steered side motor control signal Mt, and a steered side that supplies driving power to the steered side motor 43 based on the steered side motor control signal Mt. And a drive circuit 64. A known PWM inverter having a plurality of switching elements is employed in the steering side drive circuit 62 and the steered side drive circuit 64 of the present embodiment. The steering side motor control signal Ms and the steered side motor control signal Mt are gate on / off signals that define the on / off states of the switching elements of the steering side drive circuit 62 and the steered side drive circuit 64. The steering control device 1 executes each calculation process shown in each control block described below for each predetermined calculation cycle, and generates a steering side motor control signal Ms and a steered side motor control signal Mt. Then, when the steering side motor control signal Ms and the steered side motor control signal Mt are output to the steering side drive circuit 62 and the steered side drive circuit 64, each switching element is turned on / off, and the steering side motor 27 14 and the steered side motor 43 are supplied with driving power, respectively. Thereby, the operation of the steering side actuator 13 and the steering side actuator 41 is controlled.

Next, the steering side control unit 61 will be described.
The steering side controller 61 receives the vehicle speed SPD, the steering torque Trq, and the rotation angle θs. Further, the steering-side control unit 61 receives a current value Is of the steering-side motor 14 detected by a current sensor 66 provided on a connection line 65 between the steering-side drive circuit 62 and the motor coil of the steering-side motor 14. Entered. The steering side control unit 61 generates and outputs a steering side motor control signal Ms based on various state quantities of the vehicle speed SPD, the steering torque Trq, the rotation angle θs, and the current value Is. The steering motor 14 is a three-phase brushless motor. Therefore, although the connection line 65 is originally connected to the motor coil of each phase of the steering side motor 14, it is collectively shown as one for convenience of explanation.

  The steering side control unit 61 includes a target steering angle setting unit 71 that generates a target steering angle θh *, a steering side target current value calculation unit 72 that calculates a steering side target current value Is * based on the target steering angle θh *, and The torque release control unit 78 for calculating the torque release current value Im * based on the steering torque Trq, and the torque release current value Im * when the switching flag ft is input, and the steering when the switching flag ft is not input. A switching unit 77 that outputs a target side current value Is *, and a steering side motor control signal generation unit 73 that generates a steering side motor control signal Ms based on the steering side target current value Is * or the torque release current value Im *. I have. Further, the steering side control unit 61 steers the steering wheel 11 by differentiating the steering angle θh and the steering angle calculation unit 74 that calculates the steering angle θh of the steering wheel 11 based on the rotation angle θs of the steering side motor 14. And a steering speed detector 76 for calculating the speed ω. The steering angle calculation unit 74 obtains the input rotation angle θs by converting it to an absolute angle in a range exceeding 360 °, for example, by counting the rotation number of the steering side motor 14 from the steering neutral of the steering wheel 11. . Then, the steering angle calculation unit 74 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 speed reducer 15. The steering angle θh is a positive value when the steering wheel 11 is steered in one direction (right direction in the present embodiment) with respect to the steering neutral of the steering wheel 11, and the steering wheel 11 is moved in the other direction (left direction in the present embodiment). ) Is detected as a negative value.

  Further, the steering-side control unit 61 includes a determination unit 69 that determines whether or not the restriction of the steering unit 3 by the restriction unit 8 is released. When the determination unit 69 determines that the restriction unit 8 is not in the release state, the determination unit 69 outputs the non-release flag foff and the switching flag ft to the target steering angle setting unit 71. Further, the determination unit 69 outputs a release flag fon to the target steering angle setting unit 71 when determining that the restriction unit 8 is in the release state.

  As shown in FIG. 3, the target steering angle setting unit 71 includes an input torque basic component calculation unit 81 to which the steering torque Trq is input, and a reaction force control unit 82 that calculates a reaction force component Fie that increases the steering reaction force. , A target steering angle calculator 83 for calculating the target steering angle θh *, a reaction force gradual increase process and a reaction force for gradually increasing the reaction force component Fie based on the input of the release flag fon, the non-release flag foff, and the steering torque Trq. And a guard processing unit 86 that performs a torque adjustment process for adjusting the component Fie. The input torque basic component calculation unit 81 calculates an input torque basic component (reaction basic component) Tb * having a larger absolute value as the absolute value of the steering torque Trq is larger. The input torque basic component Tb * is output to the adder 84. The adder 84 calculates the input torque Trq * by adding the steering torque Trq to the input torque basic component Tb *.

  The reaction force control unit 82 calculates the reaction force component Fie by referring to the map shown in the figure based on the steering angle θh. The threshold angle θen is set in the map, and the reaction force control unit 82 calculates “0” as the reaction force component Fie when the absolute value of the steering angle θh is less than or equal to the threshold angle θen, and the steering angle When θh exceeds the threshold angle θen, a reaction force component Fie whose absolute value is larger than “0” is calculated. The reaction force component Fie calculated by the reaction force control unit 82 is output to the subtracter 85. It should be noted that the reaction force component Fie is set to have an absolute value large enough that when the steering angle θh exceeds the threshold angle θen to a certain extent and the human force cannot perform further turning steering. In other words, the reaction force component Fie makes it difficult to cut the steering wheel 11 toward the steering limit as the steering wheel 11 approaches the steering limit.

  The threshold angle θen of the present embodiment is a mechanical rack in which movement of the rack shaft 32 in the axial direction is restricted by the ball joint 35 coming into contact with the rack housing 33 in relation to the mechanical configuration of the steered portion 5. A first pinion that is a rotation shaft that can be converted into a turning angle of the steered wheels 4 in the vicinity of the virtual rack end that is positioned at a steering neutral side by a predetermined angle with respect to the virtual rack end that is set on the steering neutral side relative to the end. The value corresponding to the steering response angle θp of the shaft 31 is set. Further, the threshold angle θen is set to the steering neutral side with respect to the steering angle θh of the steering wheel 11 that is maximally allowed by the spiral cable device 21 in relation to the mechanical configuration with the steering unit 3. That is, in the steer-by-wire type steering device 2 of the present embodiment, the vicinity of the virtual rack end is set as the turning limit of the steered portion 5 (steered wheel 4) and the steering wheel allowed to the maximum by the spiral cable device 21. 11 is set as the steering angle limit of the steering unit 3, and assuming that the first pinion shaft 31 is connected to the steering shaft 12, the steering angle limit of the steering unit 3 is shifted before the steering angle limit. The steered wheel 4 reaches the rudder angle limit. Note that the virtual rack end is an example of the steering limit, and a range larger than the threshold angle θen and less than or equal to the virtual rack end is an example of the limit range.

  In the guard processing unit 86, the guard value is variably set within a predetermined range. “0” is set as the minimum value of the guard value, and the maximum value Gmax is set as the maximum value of the guard value. The guard processing unit 86 outputs the reaction force component Fie to the subtractor 85 as the corrected reaction force component Fie2 when the reaction force component Fie is less than the guard value, and is set when the reaction force component Fie is equal to or greater than the guard value. The guard value is output to the subtracter 85 as the corrected reaction force component Fie2.

When the release flag fon is input, the guard processing unit 86 performs a reaction force gradual increase process for gradually increasing the guard value for gradually increasing the reaction force component Fie output to the subtractor 85. That is, when the absolute value of the steering angle θh exceeds the threshold angle θen and the absolute value of the reaction force component Fie is greater than “0”, the guard processing unit 86 has elapsed time since the release flag fon was input. The guard value is increased from “0” to the maximum value so that the reaction force component Fie output to the subtractor 85 increases as T increases and the integrated value Ti of the steering torque Trq after the release flag fon is input increases. Gradually increase towards Gmax. The elapsed time T is a time Tth (for example, 2 seconds) at which it can be determined that the steering wheel 11 is being steered, and the integrated value Ti of the steering torque Trq turns the steered wheels 4 by steering the steering wheel 11. The guard value becomes the maximum value Gmax when the threshold value Tith is greater than or equal to the threshold value Tith that can be determined. The maximum value Gmax is set to be larger than the maximum value of the reaction force component Fie that can be output from the reaction force control unit 82.
When the non-release flag foff is input, the guard processing unit 86 performs a torque adjustment process that limits the reaction force component Fie. Here, the torque adjustment process is a process for suppressing an increase in the so-called steering reaction force that does not increase the input torque Trq *. Specifically, the guard processing unit 86 sets the guard value to “0” when the non-release flag foff is input. That is, even if the reaction force control unit 82 outputs a reaction force component Fie whose absolute value is greater than “0”, the guard processing unit 86 outputs a value of “0” to the subtractor 85 as the corrected reaction force component Fie2. The

  The subtractor 85 receives the input torque Trq * together with the corrected reaction force component Fie2 output from the guard processing unit 86. In the subtractor 85, the corrected input torque Trq ** obtained by subtracting the corrected reaction force component Fie2 from the input torque Trq * is output to the target steering angle calculation unit 83.

  The target steering angle calculation unit 83 calculates the target steering angle θh * using a model equation that relates the corrected input torque Trq ** and the target steering angle θh *. This model formula expresses the relationship between the torque and the rotation angle of the rotating shaft that rotates with the rotation of the steering wheel 11 when the steering wheel 11 and the steered wheel 4 are mechanically connected. They are represented using a viscosity coefficient C that models the friction of the steer-by-wire type steering device 2 and an inertia coefficient J that models the inertia of the steer-by-wire type steering device 2. The viscosity coefficient C and the inertia coefficient J are variably set according to the vehicle speed SPD.

  As shown in FIG. 2, an angle deviation Δθh obtained by subtracting the steering angle θh from the target steering angle θh * in the subtractor 75 is input to the steering-side target current value calculation unit 72. The steering-side target current value calculation unit 72 calculates a drive current corresponding to the steering reaction force generated by the steering-side motor 14 as a control amount for feedback-controlling the steering angle θh to the target steering angle θh * based on the angle deviation Δθh. The steering side target current value Is * which is the target value is calculated.

  The steering side motor control signal generation unit 73 receives the steering side target current value Is * or the torque release current value Im *, the rotation angle θs, and the current value Is output from the switching unit 77. The steering side motor control signal generator 73 generates a steering side motor control signal Ms to be output to the steering side drive circuit 62 by executing current feedback control in the dq coordinate system based on these various state quantities. As a result, drive power corresponding to the steering motor control signal Ms is output from the steering drive circuit 62 to the steering motor 14, and the operation of the steering motor 14 is controlled.

Next, the steered side control unit 63 will be described.
A turning angle θt and a target steering angle θh * are input to the steered side control unit 63. Further, the steered side control unit 63 includes a steered side motor 43 detected by a current sensor 68 provided on a connection line 67 between the steered side drive circuit 64 and the motor coil of the steered side motor 43. The current value It is input. The steered side control unit 63 generates and outputs a steered side motor control signal Mt based on various state quantities of the rotation angle θt, the target steering angle θh *, and the current value It. The steered side motor 43 is a three-phase brushless motor. For this reason, in the case of the main body, the connection line 67 is connected to the motor coil of each phase of the steered side motor 43, but for convenience of explanation, it is shown as one.

  The steered side control unit 63 computes the steered side target current value It * based on the target steering angle θh *, and the steered side target current value It *. And a steered side motor control signal generating unit 103 that generates a steered side motor control signal Mt. Further, the steered side control unit 63 calculates a steered corresponding angle θp of the first pinion shaft 31 which is a rotational shaft that can be converted into the steered angle of the steered wheels 4 based on the rotational angle θt of the steered side motor 43. The turning corresponding angle calculation unit 101 is provided. The steered side control unit 63 converts the input rotation angle θt into an absolute angle in a range exceeding 360 °, for example, by counting the number of rotations of the steered side motor 43 from the steering neutral where the vehicle goes straight. Get. Then, the turning correspondence angle calculation unit 101 converts the rotation angle converted to the absolute angle into the rotation speed ratio of the steered side reduction gear 44 and the rotation speed ratio of the first and second rack and pinion mechanisms 34 and 45. The turning corresponding angle θp is calculated by multiplying the conversion factor Kt based on it. That is, the steering corresponding angle θp corresponds to the steering angle θh of the steering wheel 11 when the first pinion shaft 31 is assumed to be connected to the steering shaft 12.

  An angle deviation Δθp obtained by subtracting the steering response angle θp from the target steering angle θh * in the subtractor 104 is input to the turning-side target current value calculation unit 102. Then, the steered side target current value calculation unit 102 uses the steered force generated by the steered side motor 43 as a control amount for feedback control of the steered corresponding angle θp to the target steered angle θh * based on the angle deviation Δθp. The steered side target current value It * that is the target value of the drive current corresponding to is calculated. That is, in this embodiment, the target value of the steering corresponding angle θp is equal to the target steering angle θh * that is the target value of the steering angle θh, and the steering angle ratio that is the ratio of the steering angle θh and the steering corresponding angle θp. Is set constant.

  The steered side motor control signal generation unit 103 receives the steered side target current value It *, the steered corresponding angle θp, and the current value It. The steered side motor control signal generator 103 steers by performing current feedback control in the dq coordinate system based on various state quantities of the steered side target current value It *, the steered corresponding angle θp, and the current value It. A steered side motor control signal Mt to be output to the side drive circuit 64 is generated. As a result, drive power corresponding to the steered side motor control signal Mt is output from the steered side drive circuit 64 to the steered side motor 43, and the operation of the steered side motor 43 is controlled.

  Here, in the steer-by-wire steering device 2 described above, the IGSW 9 is in an off state in a state where the steering angle θh of the steering wheel 11 is included in the limit range, that is, in a state where the steering angle θh of the steering wheel 11 exceeds the threshold angle θen. It may become. When the IGSW 9 is switched to the ON state again from this state, if the configuration in which the guard processing unit 86 is omitted from the steering control device 1 is adopted, the steering angle θh calculated by the steering angle calculation unit 74 exceeds the threshold angle θen. Therefore, the reaction force control unit 82 outputs a reaction force component Fie having an absolute value greater than “0”. That is, the steering side motor 14 may be driven. When driving of the steering side motor 14 according to the reaction force component Fie occurs before the restricting portion 8 is released, a steering reaction force is applied to the steering shaft 12 of the steering portion 3, and the restricting portion 8 The pin member 8 a is pressed against the inner peripheral surface of the through hole 12 a provided in the steering shaft 12. Accordingly, it is considered that the detachment of the pin member 8a from the through hole 12a is hindered and the restriction of the steering of the steering part 3 by the restriction part 8 is not released.

  In this regard, in the present embodiment, a determination unit 69 that determines whether or not the restriction of the steering unit 3 by the restriction unit 8 is in a released state, and a torque adjustment process is performed according to the determination result of the determination unit 69. By providing the guard processing unit 86, torque is not applied to the steering shaft 12 of the steering unit 3 before the regulating unit 8 is released.

The determination unit 69 and the torque release control unit 78 will be described in detail.
The determination unit 69 not only determines whether or not the restriction of the steering of the steering unit 3 by the restriction unit 8 is released, but also determines whether or not θh of the steering wheel 11 is included in the limit range. And a function for determining whether or not the IGSW 9 has just been switched from the OFF state to the ON state, that is, whether or not the voltage V output from the power supply circuit 6 exceeds the threshold value Vth.

  As shown in FIG. 2, steering torque Trq, voltage V, steering angle θh, and steering speed ω are input to the determination unit 69. The determination unit 69 determines whether or not the voltage V supplied from the power supply circuit 6 exceeds the threshold value Vth. The threshold value Vth indicates a voltage value at which the CPU 7 can be appropriately operated as described above. In other words, the threshold value Vth indicates a voltage value at which the operation of the steering side motor 14 can be controlled by the steering side control unit 61. . When the voltage V is less than the threshold value Vth, the determination unit 69 does not output the release flag fon, the non-release flag foff, and the switching flag ft. This is because the case where the voltage V is less than the threshold value Vth, that is, the case where the reaction force component Fie is not output from the reaction force control unit 82, and the reaction force component Fie is reduced by the torque adjustment processing by the guard processing unit 86. This is because there is no need to limit. Further, when the voltage V reaches the threshold value Vth, the determination unit 69 determines whether or not the absolute value of the steering angle θh exceeds the threshold angle θen.

  Specifically, the determination unit 69 determines whether or not the steering angle θh of the steering wheel 11 is included in the limit range. When the steering angle θh of the steering wheel 11 is not included in the limit range, the determination unit 69 does not output the release flag fon, the non-release flag foff, and the switching flag ft. This is because, when the absolute value of the steering angle θh does not exceed the threshold angle θen, the reaction force component Fie calculated by the reaction force control unit 82 is “0”, and the IGSW 9 is switched from the off state to the on state. This is because the steering side motor 14 is not operated by the reaction force component Fie. Further, when the steering angle θh of the steering wheel 11 is included in the limit range, the determination unit 69 determines whether or not the restriction of the steering of the steering unit 3 by the restriction unit 8 is in a released state.

  Specifically, when the absolute value of the steering torque Trq is larger than the torque determination value Trqth and the absolute value of the steering speed ω exceeds the speed determination value ωth, the determination unit 69 determines that the restriction unit 8 is in the release state. To do. The torque determination value Trqth and the speed determination value ωth can be obtained if there is a clearance due to tolerance formed between the steering wheel 11 and the pin member 8a of the restricting portion 8 and the through hole 12a provided in the steering shaft 12. The maximum absolute value of the steering torque Trq and the maximum absolute value of the steering speed ω when the steering wheel 11 is rotated by the gap are shown. When the determination unit 69 determines that the restriction unit 8 is in the release state, the determination unit 69 outputs a release flag fon. Further, when the absolute value of the steering torque Trq is greater than the torque determination value Trqth and the absolute value of the steering speed ω is equal to or less than the speed determination value ωth, the determination unit 69 determines that the restriction unit 8 is not in the release state. When the determination unit 69 determines that the restriction unit 8 is not in the release state, the determination unit 69 outputs a non-release flag foff and a switching flag ft.

Next, the torque release control unit 78 will be described.
In the steer-by-wire steering device 2 described above, for example, when the steering angle θh of the steering wheel 11 is included in the limit range, that is, when the steering angle θh of the steering wheel 11 exceeds the threshold angle θen, the IGSW 9 is off. In some cases, the regulation of the steering unit 3 by the regulation unit 8 may not be released.

In this regard, in the present embodiment, a torque release control unit 78 having a function of releasing the regulation of the steering of the steering unit 3 by the regulation unit 8 is provided.
When the regulation of the steering unit 3 by the regulation unit 8 is not released when the IGSW 9 is in the off state, the steering torque detected by the torque sensor 52 is detected because the torque is applied to the steering shaft 12. The absolute value of Trq is larger than “0”.

  The torque release control unit 78 calculates the torque release current value Im * so that the absolute value of the steering torque Trq approaches “0”. When the switching flag ft is input, the switching unit 77 outputs the torque release current value Im * output from the torque release control unit 78 to the steering side motor control signal generation unit 73 so that the steering side motor 14 is operated. Perform punching control. When the steering side motor 14 is operated based on the torque release current value Im * and the steering torque Trq applied to the steering shaft 12 approaches “0”, the torque acting on the restriction unit 8 is eliminated. Is released according to the command from the steering control device 1. Thereafter, as a result of repeatedly performing the same control as described above, the determination unit 69 stops the output of the switching flag ft when the steering wheel 11 is steered and the determination unit 69 determines that the restriction unit 8 is in the released state. The release flag fon is output.

A control flow of the CPU 7 of the steering control device 1, that is, the steering side control unit 61 will be described.
The steering side control unit 61 determines whether or not the voltage V exceeds the threshold value Vth through the determination unit 69 (step S101). That is, the steering side control unit 61 determines whether or not the IGSW 9 has just been switched from the off state to the on state. When determining that the voltage V does not exceed the threshold value Vth (NO in step S101), the steering control device 1 ends the process (END). When determining that the voltage V exceeds the threshold value Vth (YES in step S101), the steering-side control unit 61 determines whether the absolute value of the steering angle θh exceeds the threshold angle θen through the determination unit 69. (Step S102). That is, the steering side control unit 61 determines whether or not the steering angle θh is included in the limit range. When determining that the absolute value of the steering angle θh does not exceed the threshold angle θen (NO in step S102), the steering side control unit 61 ends the process (END). When determining that the absolute value of the steering angle θh exceeds the threshold angle θen (YES in step S102), the steering-side control unit 61 determines whether the absolute value of the steering torque Trq is greater than the torque determination value Trqth and the steering. It is determined whether or not the absolute value of the speed ω is larger than the speed determination value ωth (step S103). That is, the steering side control unit 61 determines whether or not the regulation of the steering unit 3 by the regulation unit 8 is in a released state. When it is determined that the steering side control unit 61 is not in the released state (NO in step S103), the steering side control unit 61 performs torque release control through the torque release control unit 78 (step S105). At this time, the steering-side control unit 61 performs torque adjustment processing through the guard processing unit 86 based on the non-release flag foff output from the determination unit 69, and removes torque based on the switching flag ft output from the determination unit 69. Torque relief control is performed through the controller 78, and the process is terminated (END). After that, when the regulation of the steering unit 3 by the regulation unit 8 is released after the torque release control, the steering-side control unit 61 again performs the same control as described above, and determines in step S103 that the release state is established. If so, a reaction force gradual increase process is performed through the target steering angle setting unit 71 (guard processing unit 86) (step S104). That is, the steering-side control unit 61 interrupts the torque adjustment process being executed through the guard processing unit 86 based on the release flag fon output from the determination unit 69, and reacts to the target steering angle setting unit 71 (guard processing unit 86). Carry out power increase processing.

The effect of this embodiment will be described.
(1) An increase in the steering reaction force by the reaction force control unit 82 is suppressed before the steering restriction of the steering unit 3 is released. Therefore, when the regulation of the steering of the steering unit 3 is released after the IGSW 9 is turned on, the regulation of the steering of the steering unit 3 by the regulation unit 8 can be easily released.

  (2) The control for increasing the steering reaction force by the reaction force control unit 82 may be performed when the steering angle θh of the steering wheel 11 is included in the limit range including the steering limit. In this embodiment, it implements on condition that the steering angle (theta) h of the steering wheel 11 is contained in a limit range. Therefore, the conditions which the steering control apparatus 1 implements a torque adjustment process can be optimized.

  (3) In a state where the steering angle θh of the steering wheel 11 is included in the limit range, in other words, in a state where the conditions for executing the control for increasing the steering reaction force by the reaction force control unit 82 are satisfied, When 8 is in the release state, it is conceivable that the steering reaction force is suddenly increased, so that the driver feels uncomfortable. In this regard, according to the present embodiment, even if the regulation of the steering unit 3 by the regulation unit 8 is released and the steering reaction force is increased, the guard processing unit 86 performs the reaction force gradual increase process. As a result, the steering reaction force does not increase suddenly. Therefore, it is possible to suppress the driver from feeling uncomfortable and to improve the steering feeling of the steering wheel 11.

<Second Embodiment>
Hereinafter, a second embodiment of the steer via wire type steering apparatus will be described. In addition, the same code | symbol is attached | subjected and demonstrated about the structure similar to 1st Embodiment.

As shown in FIG. 5, the steer-by-wire steering device 2 in the present embodiment is provided with a clutch 131 so that the steering unit 3 and the steered unit 5 can be mechanically coupled.
The clutch 131 is connected to the steering shaft 12 via the input side intermediate shaft 132 and is connected to the first pinion shaft 31 via the output side intermediate shaft 133. Then, the clutch 131 is released by the control signal from the steering control device 1 when the IGSW 9 is turned on, and the clutch 131 is engaged by the control signal of the steering control device 1 when the IGSW 9 is turned off. Further, when the IGSW 9 is turned off, the steering control device 1 locks the drive of the steering side motor 14. That is, even when the steering unit 3 is steered via the steering wheel 11 with the IGSW 9 turned off, the steering of the steering unit 3 is regulated by the regulation unit configured by the clutch 131 and the steering side motor 14. In the present embodiment, when the steering of the steering unit 3 is regulated by the regulating unit 8, the steering unit 3 and the steering wheel 11 cannot be rotated by human steering. Although not shown, the clutch 131 uses a meshing clutch.

  In the present embodiment, as in the first embodiment, the engagement state of the clutch 131 may not be released, and the steering restriction of the steering unit 3 may not be released. In this respect as well, in this embodiment, the same effect can be obtained by performing the same control as the steering control device 1 of the first embodiment.

  In the present embodiment, similarly to the restricting portion 8 of the first embodiment, the steering side motor 14 also has a tolerance, and even if the clutch 131 is in the engaged state, the rotation shaft of the steering side motor 14 rotates by the tolerance. That is, the steering wheel 11 can also be rotated by the amount of rotation of the rotating shaft of the steering side motor 14. In the control in the present embodiment, the steering-side control unit 61 controls the steering of the steering unit 3 by the regulating unit when the absolute value of the steering torque Trq is larger than the torque determination value Trqth2 and the steering speed ω is larger than the speed determination value ωth2. It is determined that the restriction is not in a released state. The torque determination value Trqth2 and the speed determination value ωth2 are the maximum absolute value of the steering torque Trq and the absolute value of the steering speed ω when the steering wheel 11 is rotated by the tolerance of the steering motor 14. The maximum value is shown.

  The first and second embodiments can be implemented with the following modifications. This embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.

  In the first and second embodiments, step S101 in the control flow of the steering control device 1 may be “whether the IGSW 9 has been switched from the off state to the on state”. In other words, “whether or not a signal indicating the ON state of the IGSW 9 is input to the steering control device 1” may be used. The power supply circuit 6 gradually increases the voltage V supplied from the in-vehicle power supply 27 to the steering control device 1 when the IGSW 9 is turned on until the threshold Vth is reached. At this time, the steering control device 1 may function until the voltage V reaches the threshold value Vth. In this case, since the reaction force control unit 82 may function until the voltage V reaches the threshold value Vth, the determination by the determination unit 69 is performed at an earlier timing, and it is determined whether or not the torque adjustment process is to be performed. It is preferable to do.

  In the first and second embodiments, the steering control device 1 is in a state where the steering angle θh of the steering wheel 11 is included in the limit range, and when the regulation of the steering unit 3 by the regulation unit 8 is not in the released state In addition, although torque release control is performed, the present invention is not limited to this. For example, there is a possibility that a situation where the regulation of the steering unit 3 by the regulating unit 8 described in the first and second embodiments cannot be released when the steering angle θh is not included in the limit range. Therefore, step S102 may be omitted from the control flow of the steering control device 1 shown in FIG.

In the first and second embodiments, the torque release control is performed by the steering control device 1, but this control may be omitted.
In the first embodiment, the state in which the steering of the steering unit 3 is regulated by the regulating unit 8 is such that the steering wheel 11 is rotated by a clearance due to a tolerance that can be formed between the pin member 8a and the through hole 12a. Although it was possible, it is not limited to this. For example, the configuration may be such that the space between the pin member 8a and the inner peripheral surface of the through hole 12a is eliminated, and the steering wheel 11 cannot rotate. In this case, in the determination of the steering restriction of the steering part 3 by the restriction part 8 by the steering side control part 61, the absolute value of the steering torque Trq is larger than “0” and the steering speed ω of the steering wheel 11 is “0”. Sometimes, it may be determined that the regulation of the steering unit 3 by the regulating unit 8 is not in the released state. The same applies to the second embodiment.

  In the first and second embodiments, when the steering angle θh exceeds the threshold angle θen, the steering reaction force is increased based on the reaction force component Fie. When the angle θh * is input and the target steering angle θh * exceeds the threshold angle θen, the steering reaction force may be increased by the reaction force component Fie. Further, for example, when the target turning correspondence angle or the turning correspondence angle θp exceeds the threshold angle θen, the steering reaction force may be increased based on the reaction force component Fie.

  Furthermore, in the first and second embodiments, a configuration may be adopted in which the steering angle ratio between the steering angle θh and the steering corresponding angle θp is variable. In this case, the target steering angle θh * or the steering angle θh is compared with either the target steering response angle or the steering response angle θp, and the larger one exceeds the threshold angle θen. The steering reaction force may be increased by the reaction force component Fie.

  In the first and second embodiments, the threshold angle θen is set to the value of the steering corresponding angle θp in the vicinity of the virtual rack end. However, the present invention is not limited to this. For example, when the absolute value of the steering response angle θp in the vicinity of the virtual rack end is larger than the steering angle θh at the steering angle limit of the steering wheel 11, the threshold angle θen is set to the steering angle θh. You may set to steering angle (theta) h corresponding to the neutral position side rather than a steering angle limit.

  In the first and second embodiments, the steering angle θh may be directly detected by, for example, a steering angle sensor provided on the steering shaft 12, and the steering response angle θp is provided on the first pinion shaft 31, for example. You may detect directly with an angle sensor.

  In the first and second embodiments, the steering-side target current value calculation unit 72 calculates the steering-side target current value Is * based on the angle deviation Δθh, but is not limited thereto. For example, an input torque basic component (reaction force basic component) Tb * calculated by the target steering angle setting unit 71 is further input to the steering side target current value calculation unit 72 to calculate the steering side target current value Is *. Also good. Specifically, the steering-side target current value calculation unit 72 calculates a torque correction value for making the steering angle θh coincide with the target steering angle θh * based on the angle deviation Δθh. The steering-side target current value calculation unit 72 adds a torque correction value to the input input torque basic component Tb *, and calculates a new correction input torque. The steering target current value calculator 72 calculates a steering target current value Is * based on the new corrected input torque.

  In the first and second embodiments, the corrected input torque Trq ** is calculated by subtracting the corrected reaction force component Fie2 from the input torque Trq * in the steering side control unit 61. However, the present invention is not limited to this. Absent. For example, the corrected input torque Trq ** may be calculated by multiplying the input torque basic component Tb * output from the input torque basic component calculation unit 81 by a gain. In this case, the reaction force control unit 82 has a map in which a gain corresponding to the steering angle θh is set.

  In the first and second embodiments, the engine is used as the vehicle drive source and the IGSW 9 is used as the start switch. However, the present invention is not limited to this. For example, when the vehicle on which the steer-by-wire steering device 2 is mounted is an electric vehicle, the vehicle drive source is a motor, and the start switch may be a switch for driving the motor.

  In the first and second embodiments, a model equation that relates the corrected input torque Trq ** and the target steering angle θh * by the target steering angle calculation unit 83 is used, and the model equation includes the viscosity coefficient C and This is expressed using the inertia coefficient J. For example, a model equation modeled by adding a so-called spring term using a spring coefficient Kv determined by specifications such as suspension and hole alignment is used. Also good.

  In the present embodiment, the rack shaft 32 is supported by the first rack and pinion mechanism 34 so that one end in the axial direction thereof can reciprocate. For example, the first rack and pinion is omitted from the first pinion shaft 31. The mechanism 34 may be omitted. In this case, a rack bush or the like that supports the rack shaft 32 may be provided inside the rack housing 33.

DESCRIPTION OF SYMBOLS 1 ... Steering control apparatus, 2 ... Steer-by-wire type steering apparatus, 3 ... Steering part, 4 ... Steering wheel, 5 ... Steering part, 8 ... Control part, Ignition switch (IGSW), 11 ... Steering wheel, 14 ... Steering side Motor 52. Torque sensor 61. Steering side control unit 69 69 Determination unit 76 Steering speed detection unit 82 Reaction force control unit θh Steering angle Trq Steering torque ω Steering speed Vth Threshold value, Trqth, Trqth2 ... torque judgment value, ωth, ωth2 ... speed judgment value.

Claims (7)

A steer-by-wire having a structure in which a steering unit coupled to a steering wheel and a steered unit that steers steered wheels according to the steering of the steering unit can be mechanically coupled or separated and not mechanically coupled Type steering device,
A regulating unit that regulates steering of the steering unit when a start switch of a vehicle drive source is in an off state;
A motor for applying a steering reaction force against the steering of the steering unit to the steering unit;
A steering-side control unit that controls the operation of the motor so that the steering reaction force is generated,
The steering side control unit increases the steering reaction force so that a steering angle of the steering unit does not exceed a steering limit of the steering wheel set corresponding to a steering limit of the steered wheel. And a determination unit that determines whether or not the restriction of the steering of the steering unit by the restriction is released.
The steering side control unit, when the determination unit determines that the start switch is in an on state and the restriction of steering of the steering unit by the restriction unit is released; A steer-by-wire steering device that executes torque adjustment processing that is processing for suppressing an increase in the steering reaction force by the reaction force control unit. 2. The steering-side control unit executes the torque adjustment process on the condition that the steering angle when the start switch is switched from an off state to an on state is included in a limit range including the steering limit. The steer-by-wire steering device according to 1. After the start switch is switched from the off state to the on state, the steering side control unit sets the threshold voltage at which the voltage supplied to the steering side control unit can control the operation of the motor by the steering side control unit. The steer-by-wire type steering apparatus according to claim 1, wherein the torque adjustment process is executed on condition that the steering angle at the time of reaching is included in a limit range including the steering limit. The steering side control unit interrupts the torque adjustment process when the determination unit determines that the release state is established during execution of the torque adjustment process, and the steering reaction force by the reaction force control unit. The steer-by-wire steering device according to claim 2 or 3, wherein the increase in the power is gradually increased. A torque detection unit for detecting a steering torque acting on the steering unit;
A steering speed detection unit for detecting a steering speed of the steering unit;
The determination unit determines that the steering unit is in the released state when the absolute value of the steering torque is greater than the torque determination value and the absolute value of the steering speed exceeds the speed determination value, and the absolute value of the steering torque is determined. The value is larger than the said torque determination value, and it determines with the said steering part not being the said cancellation | release state when the absolute value of the said steering speed is below the said speed determination value. Steer-by-wire steering device. When the determination unit determines that the steering switch is not in the release state when the start switch is switched from the off state to the on state, the steering side control unit is configured so that the absolute value of the steering torque approaches “0”. The steer-by-wire type steering apparatus according to claim 5, which controls operation of the motor. After the start switch is switched from the off state to the on state, the steering side control unit sets the threshold voltage at which the voltage supplied to the steering side control unit can control the operation of the motor by the steering side control unit. The steer-by-wire steering according to claim 5, wherein when the determination unit determines that the release state is not established, the operation of the motor is controlled so that the absolute value of the steering torque approaches "0". apparatus.