Steering wheel position adjustment device

Abstract

To facilitate the adjustment of a longitudinal position or a tilt angle of a steering wheel by using an existing sensor provided on the steering wheel.SOLUTION: A steering wheel position adjustment device includes sensors 12 and 13 acquiring steering information showing a steering state of a steering wheel 10, first electric motors 70 and 80 for adjusting at least one of a vertical position of the steering wheel 10 or a longitudinal position of the steering wheel, and a control unit 7 for changing at least one of the vertical position and the longitudinal position by driving the first electric motors 70 and 80 based on the steering information acquired from the sensors 12 and 13.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a steering wheel position adjustment device. [Background technology]

[0002] Electric steering column devices are known that can change the fore-aft and up-down positions (i.e., tilt angle) of a steering wheel using an electric motor. In conventional electric steering column devices, for example, when a specific lever is tilted in the fore-aft and up-down directions, the fore-aft and up-down positions change at a constant speed in the direction of the lever tilt. However, such user interface operation is not intuitive, making it difficult to operate. Furthermore, because the device cannot be operated while in the driving position, the adjusted position may not suit the driver, requiring readjustment.

[0003] For this reason, Patent Document 1 below proposes a technology in which a pressure sensor detects the vertical and longitudinal loads applied to the steering wheel, and an electric motor is driven based on the detection signal from the pressure sensor to adjust the vertical and longitudinal positions of the steering wheel. Furthermore, Patent Document 2 listed below proposes a technology for adjusting the longitudinal and vertical positions of a steering wheel by driving an electric motor based on the detection output of a load sensor provided in the grip portion of the steering wheel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-098189 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-190524 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technologies of Patent Documents 1 and 2 require the installation of new dedicated sensors to adjust the longitudinal and vertical positions of the steering wheel, which increases the number of parts, resulting in increased costs and failure rates. The present invention has been made in response to the above-mentioned problems, and aims to make it easier to adjust the forward / backward or upward / downward position of the steering wheel using existing sensors installed on the steering wheel. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a steering wheel position adjustment device according to one aspect of the present invention includes a sensor that acquires steering information indicating the steering state of the steering wheel, a first electric motor for adjusting at least one of the vertical position of the steering wheel or the longitudinal position of the steering wheel, and a control unit that changes at least one of the vertical position or the longitudinal position by driving the first electric motor based on the steering information acquired from the sensor. [Effects of the Invention]

[0007] According to the present invention, the position of the steering wheel in the forward / backward direction or the up / down direction can be easily adjusted using an existing sensor provided on the steering wheel. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing an overview of an example of a steer-by-wire system according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram illustrating the configuration of an electric tilt-telescopic mechanism. [Figure 3] FIG. 2 is a block diagram illustrating an example of a functional configuration of a control unit. [Figure 4] FIG. 10 is a control block diagram of the tilt angle and telescopic position by the micro control unit. [Figure 5]6(a) to 6(c) are schematic diagrams showing examples of setting a tilt target speed or a telescopic target speed according to steering information. [Figure 6] FIG. 1( a) is a block diagram of an example of the functional configuration of a steering angle feedback control unit that stops the rotation of the steering wheel while adjusting the tilt angle and telescopic position, and FIG. 1( b) is a block diagram of an example of a steering reaction force control unit that generates a steering reaction force while adjusting the tilt angle and telescopic position. [Figure 7] 4 is a flowchart of a first example of a steering wheel position adjusting method according to the first embodiment. [Figure 8] 6 is a flowchart of a second example of the steering wheel position adjusting method according to the first embodiment. [Figure 9] FIG. 4 is a configuration diagram showing an outline of an example of an electric power steering device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments of the present invention shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the configuration, arrangement, etc. of component parts to those described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims.

[0010] (First embodiment) (composition) 1 is a configuration diagram showing an overview of an example of a steer-by-wire (SBW) device 1 according to a first embodiment. The steer-by-wire device 1 is a system that transmits the operation of a steering device including a steering wheel 10 to a steering device that steers steered wheels WL and WR by means of an electric signal. The steer-by-wire system 1 includes a steering device 2, a turning device 3, tie rods 4a and 4b, hub units 5a and 5b, a vehicle speed sensor 6, a control unit 7, and a human machine interface (HMI) 8.

[0011] The steering device 2 includes a steering wheel 10 and a steering shaft (steering shaft, handle shaft, column shaft) 11, and the steering shaft 11 connected to the steering wheel 10 is provided with a steering angle sensor 12, a torque sensor 13, and a reduction gear 14. The steering angle sensor 12 detects an actual steering angle θs (hereinafter, sometimes simply referred to as “steering angle θs”), which is the actual steering angle of the steering shaft 11, and outputs information on the detected steering angle θs to the control unit 7.

[0012] The torque sensor 13 detects the steering torque Th of the steering shaft 11 and outputs information on the detected steering torque Th to the control unit 7. The steering device 2 further includes a reaction motor 15 connected to the steering shaft 11 via a reduction gear 14, a rotational position sensor 16, and a current sensor 30. The reaction motor 15 generates a steering reaction force to be applied to the steering shaft 11 in accordance with a control signal output from the control unit 7. The rotational position sensor 16 detects the rotational position of the rotational shaft of the reaction motor 15 and outputs information on the detected rotational position to the control unit 7. The current sensor 30 detects the reaction motor current flowing through the reaction motor 15 and outputs information on the detected value Im to the control unit 7. The reaction motor 15 is an example of a "second electric motor" as defined in the claims.

[0013] Furthermore, the steering device 2 is equipped with an electric tilt-telescopic mechanism 17 for adjusting the longitudinal and vertical positions of the steering wheel 10. In the following description, the longitudinal position of the steering wheel 10 may be referred to as the "telescopic position." Also, the vertical position of the steering wheel 10 may be simply referred to as the "tilt angle."

[0014] 2 is a schematic diagram of the electric tilt-telescopic mechanism 17. The electric tilt-telescopic mechanism 17 includes three steering columns (i.e., an upper column 40, a movable column 50, and a lower column 60) that hold the steering shaft 11 rotatably around its axis. The upper column 40 houses a universal joint (not shown) of the steering shaft 11 in its internal space. The upper column 40 is tiltably attached to a fork portion 51 formed at the rear end of a movable column 50 via a tilt hinge pin 52. The tilt angle can be adjusted by appropriately swinging the upper column 40 around the tilt hinge pin 52 as a fulcrum.

[0015] The tilt angle is adjusted by a tilt motor 70 and an extendable rod device 72 driven by the tilt motor 70 via a gearbox 71. The extendable rod device 72 may be, for example, a feed screw mechanism driven by the tilt motor 70. An actuator rod 72a extending from the extendable rod device 72 advances and retreats in response to the rotation of the tilt motor 70. The tilt motor 70 is an example of a "first electric motor" recited in the claims. The tilt motor 70 is provided with a rotational position sensor 73 that detects the rotational position of the rotational shaft of the tilt motor 70 , and the rotational position sensor 73 outputs information on the detected rotational position to the control unit 7 .

[0016] The front end of the telescopic rod device 72 is pivotally attached to a bracket 55 fixed to the movable column 50 by a pin 56, thereby forming a hinge. The rear end of the actuator rod 72a is pivotally attached to a bracket 41 fixed to the upper column 40 by a pin 42, thereby forming a hinge. By extending the actuator rod 72a from the telescopic rod device 72, the upper column 40 swings around the tilt hinge pin 52 as a fulcrum, making it possible to change the tilt angle of the steering wheel 10. In the configuration of FIG. 2, the steering wheel 10 swings upward. Conversely, by storing the actuator rod 72a inside the telescopic rod device 72, the upper column 40 can be swung in the opposite direction. In the configuration of FIG. 2, the steering wheel 10 swings downward.

[0017] The movable column 50 is fitted into and supported by the lower column 60, and is slidable in the axial direction together with the fork portion 51 that supports the upper column 40. By moving the movable column 50 back and forth relative to the lower column 60, the upper column 40 moves in the axial direction together with the steering shaft 11, and the telescopic position can be adjusted. The telescopic position is adjusted by a telescopic motor 80 and an extendable rod device 82 driven by the telescopic motor 80 via a gear box 81. The extendable rod device 82 may be, for example, a feed screw mechanism driven by the telescopic motor 80. An actuator rod 82a extending from the extendable rod device 82 advances and retreats in accordance with the rotation of the telescopic motor 80. The telescopic motor 80 is provided with a rotational position sensor 83 that detects the rotational position of the rotary shaft of the telescopic motor 80, and the rotational position sensor 83 outputs information on the detected rotational position to the control unit 7. The telescopic motor 80 is an example of a "first electric motor" as defined in the claims.

[0018] The front end of the telescopic rod device 82 is pivotally attached to a bracket 61 fixed to the lower column 60 by a pin 62, thereby forming a hinge. The rear end of the actuator rod 82a is pivotally attached to a bracket 53 fixed to the movable column 50 by a pin 54, thereby forming a hinge. By extending the actuator rod 82a from the telescopic rod device 82, the movable column 50 is extended from the lower column 60, and the steering wheel 10 can be moved backward. Conversely, by storing the actuator rod 82a inside the telescopic rod device 82, the movable column 50 is extended into the lower column 60, and the steering wheel 10 can be moved forward.

[0019] The mechanism for moving the upper column 40 and the movable column 50 by the tilt motor 70 and the telescopic motor 80 is not limited to the above mechanism, and various mechanisms may be adopted. For example, the tilt motor 70 and the telescopic motor 80 may directly drive the telescopic rod devices 72 and 82 without providing gearboxes 71 and 81. There is also no limitation on the type of the tilt motor 70 and the telescopic motor 80, and various types of motors such as brushed motors and brushless motors may be adopted. There is also no limitation on the type of the rotational position sensors 73 and 83, and various types of sensors such as hall sensors, resolvers, and encoders may be adopted.

[0020] Referring again to Figure 1, steering device 3 is equipped with pinion shaft 20 mechanically separated from steering shaft 11 of steering device 2, and rack-and-pinion mechanism 21. Steering device 3 further comprises steering motor 24 connected to pinion shaft 20 via reduction gear 23, rotational position sensor 25, and current sensor 31. Steering motor 24 generates a steering force for turning steered wheels WL and WR in accordance with a control signal output from control unit 7. Rotational position sensor 25 detects the rotational position of the rotary shaft of steering motor 24, and outputs information about the detected rotational position to control unit 7. Current sensor 31 detects the steering motor current flowing through steering motor 24, and outputs information about the detected value to control unit 7.

[0021] Rack and pinion mechanism 21 has pinion 21a connected to pinion shaft 20 and rack 21b meshing with pinion 21a, and rack 21b is connected to steered wheels WL and WR via tie rods 4a, 4b and hub units 5a, 5b. Rotational motion transmitted from steering motor 24 to pinion 21a is converted by rack 21b into linear motion in the vehicle width direction, thereby steering the steered wheels WL and WR.

[0022] The pinion shaft 20 is further provided with a steering angle sensor 22 and a torque sensor 26 . The steering angle sensor 22 detects the rotation angle of the pinion shaft 20 as the actual steering angle θt (hereinafter simply referred to as “steering angle θt”) of the steered wheels WL and WR, and outputs information on the detected steering angle θt to the control unit 7. Torque sensor 26 detects the steering torque of pinion shaft 20 and outputs information on the detected steering torque to control unit 7.

[0023] The vehicle speed sensor 6 detects the vehicle speed Vs of the vehicle, and outputs information on the detected vehicle speed to the control unit 7. The control unit 7 is an electronic control unit (ECU) including a processor such as a microcontrol unit (MCU) and peripheral components such as a storage device. Instead of the MCU, other types of processors such as a microprocessor unit (MPU) or a central processing unit (CPU) may be provided.

[0024] The control unit 7 has a plurality of operation modes including at least a normal steering mode, a tilt angle adjustment mode for adjusting the tilt angle, and a telescopic position adjustment mode for adjusting the telescopic position. The telescopic position adjustment mode and the telescopic position adjustment mode are examples of the "up-down position adjustment mode" and the "front-rear position adjustment mode" respectively described in the claims. In the normal steering mode, the control unit 7 performs steering control to control the steering angle θt of the steered wheels WL and WR in response to the steering operation of the steering wheel 10 by the driver, and steering reaction force control to control the steering reaction force generated in the steering shaft 11 of the steering wheel 10.

[0025] In the tilt angle adjustment mode, the control unit 7 controls the tilt angle in response to the steering operation of the steering wheel 10. In the telescopic position adjustment mode, the control unit 7 controls the telescopic position in response to the steering operation of the steering wheel 10. The detailed configuration and operation of the control unit 7 will be described later.

[0026] The human-machine interface 8 is an interface device that exchanges information between the control unit 7 and the user. The human-machine interface 8 is equipped with an operator that accepts operational inputs from the user. The operator may be a mechanical interface device such as a button, switch, lever, dial, or keyboard, or may be a touch panel provided on a car navigation device or the like. The human-machine interface 8 may also be equipped with a speaker or buzzer for outputting alarm sounds, notification sounds, and audio information.

[0027] Next, a detailed description will be given of the configuration and operation of the control unit 7. Figure 3 is a block diagram showing an example of the functional configuration of the control unit 7. The control unit 7 includes an MCU 100, a power supply circuit 101 to which battery voltage is input from a battery 200 mounted on the vehicle, a memory device 102, motor drive circuits 110, 120, 130 and 140, and position detection circuits 111, 121, 131 and 141.

[0028] The power supply circuit 101 generates a power supply voltage from the battery voltage of the battery 200 and supplies the power supply voltage to the MCU 100 . The storage device 102 stores programs executed by the MCU 100 and various data required for the execution of the programs (i.e., the operation of the control unit 7). The functions of the control unit 7 described below are realized by the MCU 100 executing the programs stored in the storage device 102.

[0029] In response to an operation of the human-machine interface 8 by a user, the MCU 100 switches the operation mode of the control unit 7 between a normal steering mode, a tilt angle adjustment mode, and a telescopic position adjustment mode.

[0030] In the normal steering mode, MCU 100 controls the turning angle θt of the steered wheels WL and WR based on the steering angle θs detected by steering angle sensor 12. Specifically, MCU 100 calculates the target turning angle θttrg of the steered wheels WL and WR based on the steering angle θs. MCU 100 outputs a drive signal to motor drive circuit 140 to drive and control steering motor 24 so as to reduce the difference between the turning angle θt detected by steering angle sensor 22 and the target turning angle θttrg. Motor drive circuit 140 drives and controls steering motor 24 based on a drive signal from MCU 100. For example, MCU 100 may use PWM control to control the torque of steering motor 24. "Torque control" refers to control in which a target torque for the electric motor is set and the torque generated by the electric motor is brought closer to the target torque. Position detection circuit 141 detects the rotational position of the rotary shaft of steering motor 24 based on the detection signal of rotational position sensor 25 provided in steering motor 24, and outputs information on the detected rotational position to MCU 100.

[0031] Furthermore, in the normal steering mode, the MCU 100 performs steering reaction force control to control the steering reaction force generated in the steering shaft 11 of the steering wheel 10. The steering reaction force control performed in the normal steering mode is hereinafter referred to as "first steering reaction force control." Specifically, the MCU 100 calculates a target reaction force torque Tref based on the steering angle θs and the vehicle speed Vs detected by the vehicle speed sensor 6. The MCU 100 outputs a drive signal to the motor drive circuit 130 to drive and control the reaction force motor 15 so as to reduce the difference between the steering torque Th detected by the torque sensor 13 and the target reaction force torque Tref. For example, the MCU 100 may use PWM control to control the torque of the reaction motor 15. The position detection circuit 131 detects the rotational position of the rotary shaft of the reaction motor 15 based on the detection signal of the rotational position sensor 16 provided in the reaction motor 15, and outputs information on the detected rotational position to the MCU 100.

[0032] In the tilt angle adjustment mode, the MCU 100 outputs a drive signal to the motor drive circuit 110 to drive and control the tilt motor 70 based on steering information of the steering wheel 10. The steering information of the steering wheel 10 may be, for example, the steering torque Th detected by the torque sensor 13 or the steering angle θs detected by the steering angle sensor 12. The motor drive circuit 110 drives the tilt motor 70 based on a drive signal from the MCU 100 to change the tilt angle of the steering wheel 10 . Furthermore, the position detection circuit 111 detects the rotational position of the rotation shaft of the tilt motor 70 based on the detection signal of the rotational position sensor 73 provided on the tilt motor 70 , and outputs information on the detected rotational position to the MCU 100 .

[0033] In addition, in the telescopic position adjustment mode, the MCU 100 outputs a drive signal for controlling the drive of the telescopic motor 80 to the motor drive circuit 120 based on steering information of the steering wheel 10. The motor drive circuit 120 drives the telescopic motor 80 based on the drive signal from the MCU 100, thereby changing the telescopic position of the steering wheel 10. Furthermore, the position detection circuit 121 detects the rotational position of the rotary shaft of the telescopic motor 80 based on a detection signal from a rotational position sensor 83 provided on the telescopic motor 80, and outputs information on the detected rotational position to the MCU 100.

[0034] 4 is a control block diagram of the tilt angle and telescopic position by the MCU 100. The MCU 100 includes a target speed setting unit 150, a tilt speed control unit 151, motor speed calculation units 152 and 154, and a telescopic speed control unit 153. In the tilt angle adjustment mode, the target speed setting unit 150 sets a tilt target speed Vtiref, which is a target value for the rotation speed of the tilt motor 70, according to the steering information (i.e., the steering torque Th or the steering angle θs), and outputs it to the tilt speed control unit 151. In addition, in the telescopic position adjustment mode, the target speed setting unit 150 sets a telescopic target speed Vteref, which is a target value for the rotation speed of the telescopic motor 80, according to the steering information, and outputs it to the telescopic speed control unit 153.

[0035] The target speed setting unit 150 includes a noise removal unit 160, a tilt target speed setting unit 161, limiters 162 and 165, multipliers 163 and 166, a telescopic target speed setting unit 164, a vehicle speed determination unit 167, a mode determination unit 168, and selectors 169 and 170. The noise removal unit 160 removes noise contained in the steering information (i.e., the steering torque Th detected by the torque sensor 13 or the steering angle θs detected by the steering angle sensor 12). For example, the noise removal unit 160 may be a low-pass filter that removes high-frequency signals.

[0036] Tilt target speed setting unit 161 sets a tilt target speed Vtiref according to the steering information and outputs it to limiter 162. For example, tilt target speed setting unit 161 may set a higher tilt target speed Vtiref as the value of the steering information (i.e., steering torque Th or steering angle θs) increases. 5(a) to 5(c) are schematic diagrams showing examples of setting the tilt target speed Vtiref according to steering information.

[0037] For example, tilt target velocity setting unit 161 may set tilt target velocity Vtiref so that it monotonically increases as the steering information value increases, as shown in Figures 5(a) and 5(b). The tilt target velocity Vtiref shown in Figure 5(a) increases nonlinearly with an increase in the steering information value, and the larger the absolute value of the steering information, the larger the absolute value of the rate of change of tilt target velocity Vtiref with respect to the steering information (Vtiref / steering information). The tilt target velocity Vtiref shown in Figure 5(b) increases linearly with an increase in the steering information value.

[0038] Furthermore, tilt target speed setting unit 161 may set a constant tilt target speed Vtiref regardless of the magnitude of the steering information value. For example, tilt target speed Vtiref shown in Fig. 5(c) is a positive fixed value "V1" when the steering information value is greater than "0", and is a negative fixed value "-V1" when the steering information value is less than "0". 4 again, limiter 162 limits the upper and lower limits of tilt target velocity Vtiref output from tilt target velocity setting unit 161, and then inputs the result to multiplier 163.

[0039] The telescoping target speed setting unit 164 sets a telescoping target speed Vteref according to the steering information and outputs it to the limiter 165. For example, the telescoping target speed setting unit 164 may set a higher telescoping target speed Vteref as the value of the steering information increases. Alternatively, the telescoping target speed setting unit 164 may set a constant telescoping target speed Vteref regardless of the magnitude of the value of the steering information. An example of setting the telescoping target speed Vteref according to the steering information is the same as the tilt target speed Vtiref described with reference to FIGS. 5(a) to 5(c).

[0040] The limiter 165 limits the upper and lower limits of the telescopic target speed Vteref output from the telescopic target speed setting unit 164 and then inputs the limit value to a multiplier 166 . Multipliers 163 and 166 and a vehicle speed determination unit 167 prohibit the output of tilt target speed Vtiref and telescopic target speed Vteref based on the vehicle speed Vs detected by the vehicle speed sensor 6.

[0041] For example, output of the tilt target speed Vtiref and the telescopic target speed Vteref may be prohibited when the vehicle speed Vs is greater than the threshold Vt. For example, by setting the threshold Vt to "0" or an extremely low speed (for example, 5 km / h), it is possible to prevent the tilt angle and telescopic position from changing due to operation of the steering wheel 10 while the vehicle is moving. Specifically, the vehicle speed determination unit 167 outputs a vehicle speed determination signal Sv that indicates the result of comparing the vehicle speed Vs with the threshold value Vt. The vehicle speed determination signal Sv has a value of "0" when the vehicle speed Vs is greater than the threshold value Vt, and has a value of "1" when the vehicle speed Vs is equal to or less than the threshold value Vt.

[0042] Multipliers 163 and 166 multiply the tilt target speed Vtiref and the telescopic target speed Vteref output from the limiters 162 and 165 by the vehicle speed determination signal Sv, and output the multiplication results to selectors 170 and 169. As a result, when the vehicle speed Vs is equal to or less than the threshold value Vt, the tilt target speed Vtiref and the telescopic target speed Vteref are input to the selectors 170 and 169. On the other hand, when the vehicle speed Vs is greater than the threshold value Vt, the value "0" is input to the selectors 170 and 169, prohibiting the output of the tilt target speed Vtiref and the telescopic target speed Vteref.

[0043] The mode determination unit 168 receives the mode signal Sm from the human-machine interface 8. The mode signal Sm is a signal that indicates whether the operation mode of the control unit 7 is the normal steering mode, the tilt angle adjustment mode, or the telescopic position adjustment mode. The mode determination unit 168 generates the selection signals Sti and Ste based on the mode signal Sm and outputs the selection signals Sti and Ste to the selectors 170 and 169.

[0044] The selection signal Sti is a binary signal that indicates whether the operation mode is the tilt angle adjustment mode. For example, the selection signal Sti may be a signal that has a value of "1" when the operation mode is the tilt angle adjustment mode, and a value of "0" when the operation mode is the normal steering mode or the telescopic position adjustment mode. The selection signal Ste is a binary signal that indicates whether the operation mode is the telescopic position adjustment mode or not. For example, the selection signal Ste may have a value of "1" when the operation mode is the telescopic position adjustment mode, and a value of "0" when the operation mode is the normal steering mode or the tilt angle adjustment mode.

[0045] When the selection signal Sti is "1" (i.e., when the operation mode is the tilt angle adjustment mode), selector 170 selects tilt target velocity Vtiref and outputs it to tilt velocity control unit 151. When the selection signal Sti is "0" (i.e., when the operation mode is not the tilt angle adjustment mode), selector 170 selects the value "0" and outputs it to tilt velocity control unit 151. As a result, when the operation mode is the tilt angle adjustment mode, tilt target velocity Vtiref is output from target velocity setting unit 150 to tilt velocity control unit 151.

[0046] When the selection signal Ste is "1" (i.e., when the operation mode is the telescopic position adjustment mode), the selector 169 selects the telescopic target speed Vteref and outputs it to the telescopic speed control unit 153. When the selection signal Ste is "0" (i.e., when the operation mode is not the telescopic position adjustment mode), the selector 169 selects the value "0" and outputs it to the telescopic speed control unit 153. As a result, when the operation mode is the telescopic position adjustment mode, the telescopic target speed Vteref is output from the target speed setting unit 150 to the telescopic speed control unit 153.

[0047] The motor speed calculation unit 152 calculates the rotation speed of the rotation shaft of the tilt motor 70 based on the rotation position of the rotation shaft of the tilt motor 70 input from the position detection circuit 111. For example, the rotation speed is calculated by differentiating the rotation position. The tilt speed control unit 151 calculates the speed deviation between the rotation speed calculated by the motor speed calculation unit 152 and the tilt target speed Vtiref. The tilt speed control unit 151 outputs a drive signal for driving and controlling the tilt motor 70 to the motor drive circuit 110 based on the calculated speed deviation. For example, the tilt speed control unit 151 multiplies the speed deviation by a speed loop gain to calculate a current command value for the motor current. The tilt speed control unit 151 outputs a PWM signal for controlling the on / off of a switching element of the motor drive circuit 110 based on the calculated current command value.

[0048] On the other hand, the motor speed calculation unit 154 calculates the rotation speed of the rotation shaft of the telescopic motor 80 based on the rotation position of the rotation shaft of the telescopic motor 80 input from the position detection circuit 121. For example, the rotation speed is calculated by differentiating the rotation position. The telescopic speed control unit 153 calculates the speed deviation between the rotation speed calculated by the motor speed calculation unit 154 and the telescopic target speed Vteref. The telescopic speed control unit 153 outputs a drive signal for driving and controlling the telescopic motor 80 to the motor drive circuit 120 based on the calculated speed deviation. For example, the telescopic speed control unit 153 multiplies the speed deviation by a speed loop gain to calculate a current command value for the motor current. The telescopic speed control unit 153 outputs a PWM signal for controlling the on / off of a switching element of the motor drive circuit 120 based on the calculated current command value.

[0049] In the above description, a drive signal for driving and controlling the tilt motor 70 is generated by speed feedback control based on the speed deviation between the rotation speed calculated by the motor speed calculation unit 152 and the tilt target speed Vtiref, and a drive signal for driving and controlling the telescopic motor 80 is generated by speed feedback control based on the speed deviation between the rotation speed calculated by the motor speed calculation unit 154 and the telescopic target speed Vteref, but the present invention is not limited to this. The MCU 100 may use other control methods that control the rotation speeds of the tilt motor 70 and the telescopic motor 80 so that the rotation speeds become higher as the value of the steering information becomes larger. For example, the tilt speed control unit 151 and the telescopic speed control unit 153 may generate drive signals for driving and controlling the tilt motor 70 and the telescopic motor 80 by open-loop control based on the tilt target speed Vtiref and the telescopic target speed Vteref.

[0050] Furthermore, when the operation mode of the control unit 7 is the tilt angle adjustment mode or the telescopic position adjustment mode, the MCU 100 controls the reaction motor 15 to apply a rotational driving force in the direction opposite to the steering direction of the steering wheel 10 by the user. For example, when the steering information of the steering wheel 10 used for adjusting the tilt angle or the telescopic position is the steering torque Th, a steering angle feedback control that maintains the steering angle θs at the target steering angle θsr causes the reaction motor 15 to generate a steering reaction torque so that the steering wheel 10 does not rotate while the user is adjusting the tilt angle or the telescopic position.

[0051] 6(a) is a block diagram of an example of the functional configuration of a steering angle feedback control unit that stops the rotation of the steering wheel 10 when the steering information used to adjust the tilt angle or telescopic position is the steering torque Th. The steering angle feedback control unit 180 includes subtractors 181, 184, and 186, a position controller 182, a differentiator 183, a speed controller 185, and a current controller 187. The subtractor 181 calculates the position deviation between the actual steering angle θs detected by the steering angle sensor 12 and the target steering angle θsr. For example, the steering angle feedback control unit 180 may set the steering angle θs detected by the steering angle sensor 12 as the target steering angle θsr when the tilt angle adjustment mode or the telescopic position adjustment mode is started.

[0052] The position controller 182 outputs a speed command value ωr for the steering angular velocity based on the position deviation detected by the subtractor 181. For example, the position controller 182 may calculate the speed command value ωr by multiplying the position deviation by a position loop gain. A differentiator 183 differentiates the actual steering angle θs to calculate a steering angular velocity ωs of the steering wheel 10. A subtractor 184 calculates a velocity deviation between the steering angular velocity ωs and the velocity command value ωr.

[0053] Based on the speed deviation, the speed controller 185 calculates a current command value Ir for the reaction motor current of the reaction motor 15. For example, the speed controller 185 may calculate the current command value Ir by multiplying the speed deviation by a speed loop gain. Subtractor 186 calculates the current deviation between reaction force motor current Im detected by motor current sensor 30 and current command value Ir.

[0054] The current controller 187 calculates a voltage command value by PI control or the like to make the current deviation zero, and based on the calculated voltage command value, outputs a PWM signal that controls the on / off of the switching element of the motor drive circuit 130 that drives the reaction force motor 15. As a result, the reaction force motor 15 generates a steering reaction force to maintain the actual steering angle θs at the target steering angle θsr, thereby preventing the steering wheel 10 from rotating while the user is adjusting the tilt angle or telescopic position. It is also possible to provide a mechanical stop mechanism that restricts the rotation of the steering wheel 10 or the steering shaft 11, thereby prohibiting the steering wheel 10 from rotating while the user is adjusting the tilt angle or telescopic position.

[0055] On the other hand, when the steering information of the steering wheel 10 used for adjusting the tilt angle or the telescopic position is the steering angle θs, the MCU 100 generates a steering reaction torque according to the steering angle θs and controls the reaction motor 15 by implementing soft end stop control so that the steering can be performed up to a certain steering angle. The "soft end stop control" is a control that generates a large steering reaction torque when the steering angle θs reaches a threshold value θth or -θth, thereby simulating the feeling of the steering wheel 10 hitting the end. Note that the steering angle θs at the time of switching from the normal steering mode to the tilt angle adjustment mode or the telescopic position adjustment mode is considered to be 0°, and the tilt target speed Vtiref or the telescopic target speed Vteref is set based on Fig. 5. This prevents the steering wheel position adjustment from starting suddenly if the steering angle θs is not 0° when switching from the normal steering mode to the tilt angle adjustment mode or the telescopic position adjustment mode. If the steering angle θs exceeds a predetermined angle when switching from the normal steering mode to the tilt angle adjustment mode or the telescopic position adjustment mode, the user is notified that the tilt angle adjustment mode or the telescopic position adjustment mode cannot be selected by the human-machine interface 8. Examples of the predetermined angle include a threshold value θth-10° or -θth+10°.

[0056] 6(b) is a block diagram of an example of a steering reaction force control unit that generates a steering reaction force during adjustment of the tilt angle and telescopic position when the steering information used for adjusting the tilt angle or telescopic position is the steering angle θs. The steering reaction force control performed by the steering reaction force control unit 190 will be referred to as "second steering reaction force control" below. The steering reaction force control unit 190 includes a basic reaction torque setting unit 191 , an end contact reaction torque setting unit 192 , an adder 193 , a subtractor 194 , and a current controller 195 .

[0057] The basic reaction torque setting unit 191 calculates a basic reaction torque Trb that increases as the steering angle θs increases. For example, the basic reaction torque Trb is calculated by simulating the static characteristics of the steering reaction. In order to simulate the feeling of end contact of the steering wheel 10, the end contact reaction torque setting unit 192 sets an end contact reaction torque Tre, which is a reaction torque in the opposite direction to the steering direction when the steering angle θs reaches the threshold value θth or −θth. An adder 193 calculates the sum of the basic reaction torque Trb set by the basic reaction torque setting unit 191 and the end contact reaction torque Tre set by the end contact reaction torque setting unit 192 as target steering reaction torque Tr=Trb+Tre.

[0058] The subtractor 194 calculates the torque deviation between the target steering reaction force Tr output from the adder 193 and the steering torque Th detected by the torque sensor 13 . The current controller 195 calculates a voltage command value by PI control or the like to make the torque deviation zero, and outputs a PWM signal that controls the on / off of the switching element of the motor drive circuit 130 that drives the reaction force motor 15 based on the calculated voltage command value.

[0059] (operation) Fig. 7 is a flowchart of a first example of the steering wheel position adjustment method of the first embodiment. The flowchart in Fig. 7 shows the steering wheel position adjustment method when the steering information used to adjust the tilt angle or telescopic position is the steering torque Th.

[0060] In step S10, the MCU 100 determines whether the operation mode of the control unit 7 is the tilt angle adjustment mode or the telescopic position adjustment mode. If the operation mode is the tilt angle adjustment mode or the telescopic position adjustment mode (step S10: Y), the process proceeds to step S12. If the operation mode is the normal steering mode (step S10: N), the process proceeds to step S11. In step S11, the MCU 100 executes the first steering reaction force control, and then the process ends.

[0061] On the other hand, in step S12, the steering angle feedback control unit 180 performs steering angle feedback control to stop the rotation of the steering wheel 10. In step S13, the mode determination unit 168 determines whether the operation mode of the control unit 7 is the telescopic position adjustment mode. If the operation mode is the telescopic position adjustment mode (step S13: Y), the process proceeds to step S14. If the operation mode is the tilt angle adjustment mode (step S13: N), the process proceeds to step S17.

[0062] In step S14, the telescopic target speed setting unit 164 and the limiter 165 set the telescopic target speed Vteref. In step S15, the telescopic speed control section 153 outputs a drive signal to the motor drive circuit 120 to drive and control the telescopic motor 80 so that the rotation speed of the telescopic motor 80 becomes the telescopic target speed Vteref. In step S16, the motor drive circuit 120 drives the telescopic motor 80 based on the drive signal output from the telescopic speed control unit 153. Thereafter, the process ends.

[0063] On the other hand, in step S17, tilt target speed setting unit 161 and limiter 162 set tilt target speed Vtiref. In step S18, tilt speed control section 151 outputs a drive signal to motor drive circuit 110 to drive and control tilt motor 70 so that the rotation speed of tilt motor 70 becomes tilt target speed Vtiref. In step S19, motor drive circuit 110 drives tilt motor 70 based on the drive signal output from tilt speed control section 151. Thereafter, the process ends.

[0064] Fig. 8 is a flowchart of a second example of the steering wheel position adjustment method according to the first embodiment. The flowchart in Fig. 8 shows the steering wheel position adjustment method when the steering information used to adjust the tilt angle or telescopic position is the steering angle θs. The processes of steps S20 and S21 are the same as the processes of steps S10 and S11 shown in Fig. 7. If the operation mode is the tilt angle adjustment mode or the telescopic position adjustment mode (step S20: Y), the process proceeds to step S22. In step S22, the steering reaction force control unit 190 performs the second steering reaction force control. The processing in steps S23 to S29 is the same as the processing in steps S13 to S19 shown in FIG.

[0065] (Second embodiment) The steering wheel position adjusting device and steering wheel position adjusting method of the present invention can also be applied to electric power steering (EPS). 9 is a configuration diagram showing an overview of an example of an electric power steering device 300 according to the second embodiment. The electric power steering device 300 according to the second embodiment has the same components as the steer-by-wire device 1 according to the first embodiment. Therefore, the same components are denoted by the same reference numerals.

[0066] In the electric power steering device 300, an assist motor 18 that assists the steering force of the steering wheel 10 is connected to the steering shaft 11 via a reduction gear 14, and the assist motor 18 is provided with a rotational position sensor 19 and a current sensor 32. The rotational position sensor 19 detects the rotational position of the rotary shaft of the assist motor 18 and outputs information on the detected rotational position to the control unit 7. The current sensor 32 detects the assist motor current flowing through the assist motor 18 and outputs information on the detected value Im2 to the control unit 7. Note that FIG. 9 shows an example of a column assist type electric power steering device, also known as an upstream assist type, in which the assist motor 18 is connected to the steering shaft 11 to provide assisting power, but the present invention can also be applied to downstream assist type electric power steering devices such as a single pinion assist type in which the assist motor is connected to the pinion shaft to provide assisting power, a rack assist type in which the assist motor is connected to a rack to provide assisting power, or a dual pinion assist type in which the assist motor is connected to an assist pinion shaft provided separately from the pinion shaft to provide assisting power.

[0067] 9, a clutch 27 may be provided to transmit and interrupt rotational motion between the steering wheel 10 and the pinion shaft 20. The clutch 27 is disposed between the steering shaft 11 and a lower shaft 28. The lower shaft 28 is connected to the pinion shaft 20 via a universal joint 29a of an intermediate shaft 29, a shaft member 29c, and a universal joint 29b.

[0068] When the operation mode of the control unit 7 is the normal steering mode, the MCU 100 calculates a steering assist command value of the assist command using an assist map or the like based on the steering torque Th detected by the torque sensor 13 and the vehicle speed Vs detected by the vehicle speed sensor 6. The MCU 100 controls the drive of the assist motor 18 based on the steering assist command value. As a result, the torque generated by the assist motor 18 is applied to the steering system as an assist force (steering assist force) for the driver's steering operation.

[0069] On the other hand, when the operation mode of the control unit 7 is the tilt angle adjustment mode, the MCU 100 controls the tilt motor 70 in response to the steering operation of the steering wheel 10 to control the tilt angle. Also, when the operation mode is the telescopic position adjustment mode, the MCU 100 controls the telescopic position by controlling the telescopic motor 80 in response to the steering operation of the steering wheel 10. The control of the tilt motor 70 and the telescopic motor 80 is the same as the control in the first embodiment.

[0070] Furthermore, when the operation mode is the tilt angle adjustment mode or the telescopic position adjustment mode, the MCU 100 may release the clutch 27. By releasing the clutch 27, even if the user steers the steering wheel 10 in the tilt angle adjustment mode or the telescopic position adjustment mode, the steered wheels WL and WR can be prevented from being turned.

[0071] Furthermore, similar to the first embodiment, when the operation mode is the tilt angle adjustment mode or the telescopic position adjustment mode, the MCU 100 controls the assist motor 18 to apply a rotational driving force in the direction opposite to the steering direction of the steering wheel 10 by the user. The assist motor 18 is an example of a "second electric motor" as defined in the claims. 6(a) may drive the assist motor 18 instead of the reaction motor 15, thereby causing the assist motor 18 to generate a steering reaction torque so that the steering wheel 10 does not rotate while the user is adjusting the tilt angle or the telescopic position. In this case, the subtractor 186 calculates the current deviation between the current command value Ir and the assist motor current Im2 detected by the current sensor 32 instead of the reaction motor current Im.

[0072] Further, for example, the steering reaction force control unit 190 in FIG. 6(b) may drive the assist motor 18 instead of the reaction force motor 15 to generate a steering reaction force torque according to the steering angle θs, and may also perform a soft end stop control to perform a second steering reaction force control so that steering is possible up to a certain steering angle.

[0073] 1 may also be provided with a backup clutch that transmits and interrupts rotational motion between the steering wheel 10 and the pinion shaft 20. By engaging and disengaging the backup clutch, it is possible to switch between a steer-by-wire mode in which the system operates as a steer-by-wire system and an electric power steering mode in which the system operates as an electric power steering system.

[0074] When the backup clutch is engaged and the steer-by-wire system 1 is used as an electric power steering system, either or both of the reaction motor 15 and the steering motor 24 are used as assist motors to generate an assisting steering torque that assists the steering force of the steering wheel 10. Even when steer-by-wire system 1 is used as an electric power steering system in this way, MCU 100 can adjust the tilt angle and telescopic position in response to the steering operation of steering wheel 10, as in the first and second embodiments. Furthermore, when the operation mode is the tilt angle adjustment mode or the telescopic position adjustment mode, MCU 100 can generate a rotational drive force in the direction opposite to the steering direction of steering wheel 10 by the user, using either or both of reaction force motor 15 and steering motor 24.

[0075] (Effects of the embodiment) (1) The steering angle sensor 12 or the torque sensor 13 acquires the steering angle θs or the steering torque Th as steering information indicating the steering state of the steering wheel 10. The tilt angle of the steering wheel 10 is adjusted by the tilt motor 70. The telescopic position of the steering wheel 10 is adjusted by the telescopic motor 80. The control unit 7 changes the tilt angle or the telescopic position by driving the tilt motor 70 or the telescopic motor 80 based on the steering information acquired from the steering angle sensor 12 or the torque sensor 13. This allows the tilt angle and telescopic position to be adjusted using existing sensors provided on the steering wheel 10. Also, since the operation can be performed while in the driving position, the tilt angle and telescopic position can be easily adjusted.

[0076] (2) The human-machine interface 8 may accept a user operation to select between a tilt angle adjustment mode for adjusting the tilt angle and a telescopic position adjustment mode for adjusting the telescopic position. When the human-machine interface 8 accepts an operation to select the tilt angle adjustment mode, the control unit 7 may change the tilt angle based on the steering information. When the human-machine interface 8 accepts an operation to select the telescopic position adjustment mode, the control unit 7 may change the telescopic position based on the steering information. This allows the user to select and adjust the tilt angle and telescopic position.

[0077] (3) The steering information may be the steering torque Th applied to the steering wheel 10 or the steering angle θs of the steering wheel 10. This allows the tilt angle and telescopic position to be adjusted using the existing torque sensor 13 and steering angle sensor 12 provided on the steering wheel. (4) The control unit 7 may perform control such that the rotation speed of the tilt motor 70 or the telescopic motor 80 increases as the steering torque Th or the steering angle θs increases. This allows the user to make a rough adjustment by increasing the steering torque Th or the steering angle θs, and to make a fine adjustment by decreasing the steering torque Th or the steering angle θs.

[0078] (5) The control unit 7 may limit the rotation speed of the first electric motor to a predetermined upper limit value or less. This makes it possible to prevent the rate of change of the tilt angle and telescopic position from becoming excessive. (6) The reaction motor 15 applies a rotational driving force to the steering shaft 11 to which the steering wheel 10 is connected. When changing at least one of the tilt angle and the telescopic position based on the steering information, the control unit 7 may control the reaction motor 15 to apply a rotational driving force in the direction opposite to the steering direction of the steering wheel 10. This prevents the steering wheel 10 from easily rotating when adjusting the tilt angle or telescopic position, thereby preventing the tilt angle or telescopic position from changing excessively.

[0079] (7) When the control unit 7 changes at least one of the tilt angle or the telescopic position based on the steering torque Th applied to the steering wheel as steering information, the control unit 7 may control the reaction motor 15 so that the steering wheel 10 does not rotate even when the steering wheel 10 is operated. This makes it easier for the user to increase or decrease the steering torque Th on the steering wheel 10 when adjusting the tilt angle or telescopic position.

[0080] (8) When the control unit 7 changes at least one of the tilt angle and the telescopic position based on the steering information, the control unit 7 may release the clutch 27 provided between the steering wheel 10 and the steered wheels WL and WR. This prevents the steered wheels WL and WR from being steered even if the user turns the steering wheel 10. [Explanation of symbols]

[0081] 1...steer-by-wire device, 2...steering device, 3...turning device, 4a, 4b...tie rod, 5a, 5b...hub unit, WL, WR...steered wheels, 6...vehicle speed sensor, 7...control unit, 8...human-machine interface, 10...steering wheel, 11...steering shaft, 12...steering angle sensor, 13, 26...torque sensor, 14, 23...reduction gear, 15...reaction motor, 16, 19, 25, 73, 83...rotational position sensor, 17...electric tilt-telescopic mechanism, 18...assist motor, 20...pinion shaft, 21...rack-and-pinion mechanism, 22...steering angle sensor, 24...steering motor, 27...clutch, 28...lower shaft, 29...intermediate shaft, 70...tilt motor, 80...telescopic motor, 100...microcontrol unit, 101...power supply circuit, 102...storage device, 110, 120, 130, 140... Motor drive circuit, 111, 121, 131, 141... Position detection circuit, 150... Target speed setting unit, 151... Tilt speed control unit, 152, 154... Motor speed calculation unit, 153... Telescopic speed control unit, 160... Noise removal unit, 161... Tilt target speed setting unit, 162, 165... Limiter, 163, 166... ​​Multiplier, 164... Telescopic target speed setting unit, 167... Vehicle speed determination unit, 168... Mode determination unit, 169, 170... selector, 180... steering angle feedback control unit, 181, 184, 186, 194... subtractor, 182... position controller, 183... differentiator, 185... speed controller, 187... current controller, 190... steering reaction force control unit, 191... basic reaction force torque setting unit, 192... reaction force torque setting unit, 193... adder, 195... current controller, 200... battery, 300... electric power steering device

Claims

1. a sensor for acquiring steering information indicating the steering state of a steering wheel; a first electric motor for adjusting at least one of a vertical position and a longitudinal position of the steering wheel; a control unit that changes at least one of the vertical position and the longitudinal position by driving the first electric motor based on the steering information acquired from the sensor; a second electric motor that applies a rotational driving force to a steering shaft to which the steering wheel is connected; Equipped with A steering wheel position adjustment device characterized in that the control unit controls the second electric motor to apply a rotational driving force in the direction opposite to the steering direction of the steering wheel when changing at least one of the vertical position or the longitudinal position based on the steering information.

2. a user interface that accepts a user's operation to select a vertical position adjustment mode for adjusting the vertical position and a front-rear position adjustment mode for adjusting the front-rear position, the control unit changes the vertical direction position based on the steering information when the user interface receives an operation to select the vertical direction position adjustment mode, and changes the longitudinal direction position based on the steering information when the user interface receives an operation to select the longitudinal direction position adjustment mode.

2. The steering wheel position adjusting device according to claim 1.

3. 3. The steering wheel position adjusting device according to claim 1, wherein the steering information is a steering torque applied to the steering wheel or a steering angle of the steering wheel.

4. 4. The steering wheel position adjusting device according to claim 3, wherein the control unit controls the first electric motor so that the rotation speed of the first electric motor increases as the steering torque or the steering angle increases.

5. 5. The steering wheel position adjusting device according to claim 4, wherein the control unit limits the rotation speed of the first electric motor to a predetermined upper limit value or less.

6. The steering wheel position adjustment device according to claim 1, characterized in that when the control unit changes at least one of the vertical position or the longitudinal position based on the steering torque applied to the steering wheel as the steering information, it controls the second electric motor so that the steering wheel does not rotate even when operated.

7. A sensor for acquiring steering information indicating the steering state of a steering wheel; a first electric motor for adjusting at least one of a vertical position and a longitudinal position of the steering wheel; a control unit that changes at least one of the vertical position and the longitudinal position by driving the first electric motor based on the steering information acquired from the sensor; Equipped with A steering wheel position adjustment device characterized in that the control unit releases a clutch provided between the steering wheel and steered wheels when changing at least one of the vertical position or the longitudinal position based on the steering information.

Images