JP2022188815A - Vehicular steering column device - Google Patents

Abstract

To provide a vehicular steering column device capable of suppressing position adjustment action which a driver does not intend, and capable of intuitively adjusting a position of a steering wheel.SOLUTION: A vehicular steering column device is equipped with a load sensor that detects a load applied to a steering wheel, a position adjusting mechanism that moves the steering wheel according to the load, an actuator that drives the position adjusting mechanism, a control portion that generates a target current value to be supplied to the actuator on the basis of the load and the moving amount of the steering wheel, and a drive portion that drive-controls the actuator on the basis of the target current value. The control portion controls to make the moving speed of the steering wheel become zero, in a first area where the load is less than a first value, and controls to increase the moving speed of the steering wheel as the load increases, in a second area where the load is the first value or more and is less than a second value that is larger than the first value.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a vehicle steering column device.

As a vehicle steering column device, a vehicle steering column device equipped with a tilt mechanism for adjusting the angle (height) of the steering wheel and a telescopic mechanism for adjusting the front-rear position of the steering wheel is known. ing. For example, in Japanese Unexamined Patent Application Publication No. 2002-100000, pressure sensors are provided to detect vertical and longitudinal loads applied to a steering wheel, and based on the detection output of these pressure sensors, a motor for a tilt mechanism and a telescopic mechanism are operated. A technique is disclosed in which the motors are respectively driven to adjust the position of the steering wheel along the load acting direction.

JP 2015-98189 A

In the prior art described above, when adjusting the position of the steering wheel, the driver needs to operate the steering wheel adjustment start switch in order to prevent the position adjustment operation not intended by the driver. For this reason, when the driver feels uncomfortable with the steering position, there is a possibility that this may hinder the driver from adjusting the position of the steering wheel intuitively.

The present disclosure has been made in view of the above problems, and is a steering column device for a vehicle that can suppress unintended position adjustment operations by a driver and that can intuitively adjust the position of a steering wheel. is intended to provide

In order to achieve the above object, a vehicle steering column device according to an aspect of the present disclosure includes a load sensor that detects a load applied to a steering wheel, A position adjusting mechanism that moves in either the vertical direction, an actuator that drives the position adjusting mechanism, and a control unit that generates a target current value to be supplied to the actuator based on the load and the amount of movement of the steering wheel. and a driving unit that drives and controls the actuator based on the target current value, wherein the control unit controls the moving speed of the steering wheel to be zero in a first region where the load is less than a first value. and in a second region where the load is equal to or greater than the first value and is less than a second value larger than the first value, the movement speed increases as the load increases Control to grow.

According to the above configuration, the first region in which the load is less than the first value is a dead zone region in which the steering wheel does not move, and the second region in which the load is greater than or equal to the first value and less than the second value is It can be a transition region in which the speed of movement of the steering wheel increases as the load increases. As a result, it is possible to prevent erroneous operation due to steering operation and erroneous operation due to slight vibration such as road noise while driving. In addition, it is possible to suppress unintentional position adjustment operations by the driver, and to intuitively adjust the position of the steering wheel.

As a preferred aspect of the vehicle steering column device, it is preferable that the control unit controls the movement speed to increase at a predetermined slope in accordance with the increase in the load in the second region.

Thus, in the second region (transition region), the moving speed of the steering wheel linearly increases as the load increases.

As a preferred aspect of the vehicle steering column device, it is preferable that the control unit controls the slope of the moving speed in the second region so that the slope of the moving speed increases as the load increases.

According to the above configuration, in the second region (transition region), the rate of increase in the moving speed of the steering wheel gradually increases as the load increases. As a result, the optimum steering position can be obtained without being conscious of the boundary (first value) between the first region (dead band region) and the second region (transition region).

As a preferred aspect of the vehicle steering column device, the control section may perform control so that the gradient of the moving speed decreases in the second region as the vehicle speed increases.

As a desirable aspect of the vehicle steering column device, the control unit may perform control so that the slope of the moving speed increases in the second region as the time rate of change of the load increases.

As a desirable aspect of the vehicle steering column device, the control unit controls the slope of the moving speed to increase in the second area when the load exceeds a predetermined threshold value twice consecutively within a predetermined period. can be controlled to

As a preferred aspect of the vehicle steering column device, it is preferable that the control section controls the movement speed to a constant movement speed limit value in a third region where the load is equal to or greater than the second value.

As a result, the third region in which the load is equal to or greater than the second value can be set as the restricted region in which the steering wheel has a constant movement speed limit value. As a result, in the third region (restricted region), it is possible to prevent the moving speed of the steering wheel from becoming greater than the moving speed limit value.

As a preferred aspect of the vehicle steering column device, the control unit may control the movement speed limit value to decrease as the vehicle speed increases.

As a desirable aspect of the vehicle steering column device, the control unit may perform control so that the moving speed limit value increases as the time rate of change of the load increases.

As a preferred aspect of the steering column device for a vehicle, the control unit may perform control so that the moving speed limit value increases when the load exceeds a predetermined value consecutively twice within a predetermined period. .

As a preferred aspect of the steering column device for a vehicle, the position adjusting mechanism is a telescopic mechanism that moves the steering wheel in the front-rear direction by the driving force of the actuator, and the control unit controls the first position against the load in the pulling direction. It is preferable to control the value to be smaller than the first value for the load in the pushing direction.

This makes it possible to reduce the first area (dead zone area) in the pulling direction, where the load tends to be small.

As a desirable aspect of the steering column device for a vehicle, the position adjustment mechanism is a tilt mechanism for moving the steering wheel in the vertical direction by driving force of the actuator, and the control unit is configured to control the first tilt mechanism against the load in the upward direction. It is preferable to control the value to be smaller than the first value for the load in the downward direction.

This makes it possible to reduce the first area (dead zone area) in the lifting direction where the load tends to be small.

As a preferred aspect of the vehicle steering column device, it is preferable that the control section further includes a phase lead compensation section for the input of the load.

Thereby, the response speed of the position adjusting mechanism to the input of the load can be improved.

As a preferred aspect of the vehicle steering column device, the control section further includes a friction compensation section that compensates for friction of an inertial system including the actuator and the position adjustment mechanism.

This makes it possible to compensate for friction in the inertial system including the actuator and the position adjustment mechanism.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a vehicle steering column device that can suppress unintended position adjustment operations by the driver and that can intuitively adjust the position of the steering wheel.

FIG. 1 is a diagram showing the overall configuration of a steering column device for a vehicle according to Embodiment 1. FIG. FIG. 2 is a schematic diagram showing the hardware configuration of the control unit. FIG. 3 is a diagram showing an example of a control system of the vehicle steering column device according to the first embodiment. FIG. 4 is a diagram showing a first example of a speed conversion map of the vehicle steering column device according to the first embodiment. FIG. 5 is a diagram showing a second example of the speed conversion map of the vehicle steering column device according to the first embodiment. FIG. 6 is a diagram showing a third example of the speed conversion map of the vehicle steering column device according to the first embodiment. FIG. 7A is a timing chart showing a first example of changing the slope of the target speed in the second area. FIG. 7B is a timing chart showing a first example of changing the slope of the target speed in the second region. FIG. 7C is a timing chart showing a first example of changing the slope of the target speed in the second region. FIG. 8A is a timing chart showing a second example of changing the slope of the target speed in the second region. FIG. 8B is a timing chart showing a second example of changing the slope of the target speed in the second region. FIG. 9 is a diagram showing a third example of the speed conversion map of the vehicle steering column device according to the first embodiment. FIG. 10 is a diagram showing a fourth example of the speed conversion map of the vehicle steering column device according to the first embodiment. FIG. 11 is a diagram showing a fifth example of the speed conversion map of the vehicle steering column device according to the first embodiment. FIG. 12 is a diagram showing an example of a control system of the vehicle steering column device according to the second embodiment. FIG. 13 is a diagram showing an example of a control system of the vehicle steering column device according to the third embodiment. FIG. 14 is a diagram showing an example of a friction compensator.

EMBODIMENT OF THE INVENTION Hereinafter, it demonstrates in detail, referring drawings for the form (henceforth embodiment) for implementing invention. It should be noted that the present disclosure is not limited by the following embodiments. In addition, components in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that fall within a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be combined as appropriate.

(Embodiment 1)
FIG. 1 is a diagram showing the overall configuration of a steering column device for a vehicle according to Embodiment 1. FIG. As shown in FIG. 1, a vehicle steering column device 100 has a steering column 3 that rotatably supports a steering shaft 2 . A steering wheel 1 is attached to the end of the steering column 3 .

In the present disclosure, the vehicle steering column device 100 includes a load sensor 7 that detects the load applied to the steering wheel 1 by the driver, and the steering wheel 1 at least in the front-rear direction ( It has a position adjusting mechanism 4 for moving in the solid line arrow direction in the drawing) and the vertical direction (broken line arrow direction in the drawing). The load sensor 7 is exemplified by a load cell, for example. The load sensor 7 detects a load (force) applied to the steering wheel 1 and converts it into an electric signal Fh (hereinafter also simply referred to as "load Fh").

In the present disclosure, the terms “longitudinal direction” and “vertical direction” are defined based on the state in which the driver sits in the driver's seat of the vehicle facing the steering wheel 1 and looks at the steering wheel 1 . That is, the direction in which the driver pushes the steering wheel 1 forward is called the "push direction", and the direction in which the driver pulls the steering wheel 1 forward is called the "pull direction". Further, the direction in which the driver pushes up the steering wheel 1 is called the "upward direction", and the direction in which the driver pushes down the steering wheel 1 is called the "downward direction".

The position adjusting mechanism 4 is driven by the driving force of the motor 5 . In the present disclosure, motor 5 is illustrated as an example of an actuator. The position adjusting mechanism 4 may be, for example, a telescopic mechanism that moves the steering wheel 1 in the front-rear direction, or a tilt mechanism that moves the steering wheel 1 in the vertical direction. Alternatively, the position adjusting mechanism 4 may be configured to have both functions of a telescopic mechanism and a tilt mechanism. Here, the steering wheel 1 is moved in the longitudinal direction (the direction indicated by the solid line arrow in the figure) or in the vertical direction (the direction indicated by the broken line arrow in the figure). A mode in which the steering wheel 1 is moved in the vertical direction and, as a result, the steering wheel 1 is moved in the front-rear direction or the vertical direction is also possible.

In the present disclosure, as shown in FIG. 1 , the load applied to the steering wheel 1 in the pushing direction is “load Fh_Push”, the load in the pulling direction applied to the steering wheel 1 is “load Fh_Pull”, and the load applied to the steering wheel 1 is “load Fh_Pull”. The load in the direction is also referred to as "load Fh_Down", and the load in the upward direction applied to the steering wheel 1 is also referred to as "load Fh_Up".

The motor 5 is provided with an angle sensor 5a. The angle sensor 5a detects the rotation angle of the motor 5 and converts it into an electric signal θm (hereinafter also simply referred to as "motor rotation angle θm").

Further, the motor 5 is provided with a current sensor 5b. The current sensor 5b detects an actual current value flowing through the motor 5 and converts it into an electric signal Iact (hereinafter also simply referred to as "actual current value Iact").

The vehicle steering column device 100 includes a control unit 10 (hereinafter also referred to as “ECU 10 ”) and a motor driver 20 as a control entity for the position adjustment mechanism 4 . In the present disclosure, the ECU 10 corresponds to a "control section". Also, in the present disclosure, the motor driver 20 corresponds to a "driving section". The ECU 10 may control, for example, a power steering device other than the vehicle steering column device 100 .

The ECU 10 generates a target current value Iref to be supplied to the motor 5 based on the load Fh detected by the load sensor 7 and the amount of movement of the steering wheel 1 . The amount of movement of the steering wheel 1 is, for example, the amount of movement of the steering wheel 1 in the telescopic mechanism in the front-rear direction (the direction indicated by the solid line arrow in the drawing). Further, the amount of movement of the steering wheel 1 is, for example, the amount of movement of the steering wheel 1 in the vertical direction (in the direction of the dashed arrow in the figure) in the tilt mechanism. The amount of movement of the steering wheel 1 is calculated from the motor rotation angle θm detected by the angle sensor 5 a of the motor 5 .

The motor driver 20 drives and controls the motor 5 based on the target current value Iref output from the ECU 10 . Specifically, the motor driver 20 generates a PWM signal that causes the actual current value Iact flowing through the motor 5 to approach the target current value Iref, and supplies it to the motor 5 .

The ECU 10 is mainly composed of a CPU (including MCU, MPU, etc.). FIG. 2 is a schematic diagram showing the hardware configuration of the control unit.

A control computer 1100 constituting the ECU 10 includes a CPU (Central Processing Unit) 1001, a ROM (Read Only Memory) 1002, a RAM (Random Access Memory) 1003, an EEPROM (Electrically Erasable Programmable ROM) 1004, and the like. It is connected.

The CPU 1001 is a processing device that controls the vehicle steering column device 100 by executing a computer program for controlling the vehicle steering column device 100 (hereinafter referred to as a control program).

ROM 1002 stores a control program for controlling vehicle steering column device 100 . Also, the RAM 1003 is used as a work memory for operating the control program. The EEPROM 1004 stores control data and the like input/output by the control program. The control data is used in the control computer program developed in the RAM 1003 after the ECU 10 is powered on, and overwritten in the EEPROM 1004 at a predetermined timing.

A ROM 1002, a RAM 1003, an EEPROM 1004, and the like are storage devices that store information, and are storage devices (primary storage devices) that the CPU 1001 can directly access.

FIG. 3 is a diagram showing an example of a control system of the vehicle steering column device according to the first embodiment.

The ECU 10 includes a target speed generator 11, converters 13 and 14, a limiter 16, a converter 21, a limiter 22, and a duty ratio converter 26 as internal block configurations. The conversion unit 13 is, for example, a differentiator. As the differentiator, instead of using a pure differentiator, an approximate differentiator, for example, a pseudo differentiator combining a pure differentiation and a first-order lag transfer function can be used. The converter 14 is, for example, a PID controller. The converter 21 is, for example, a PI controller. The duty ratio converter 26 outputs a PWM command value corresponding to the input value that is output from the limiter 22 .

The motor driver 20 has a PWM generator 23 as an internal block configuration.

A load Fh detected by the load sensor 7 is input to the target speed generator 11 . The target speed generation unit 11 generates a target speed Vref, which is a target value of the movement speed when the position adjustment mechanism 4 moves the steering wheel 1, using a speed conversion map, which will be described later. The conversion unit 13 time-differentiates the movement amount Xact of the steering wheel 1 to calculate the actual speed Vact. The speed conversion map is stored in the ROM 1002, for example. Note that the target speed generation unit 11 may be configured to calculate the target speed Vref using, for example, a formula stored in the ROM 1002 without using the speed conversion map.

The target speed Vref is input to the converter 14 after subtracting the actual speed Vact. The converter 14 performs PID control on the input value to convert it into a current value, and outputs the current value to the limiter 16 .

An upper limit value and a lower limit value for the output value of the conversion unit 14 are preset in the limiter 16 . A limiting unit 16 limits the upper and lower limits of the output value of the converting unit 14 and outputs a target current value Iref.

The target current value Iref output from the ECU 10 is subtracted by the actual current value Iact and is input to the conversion unit 21 . The conversion unit 21 PI-controls the input value to convert it into a voltage value, and outputs the voltage value to the limiter 22 .

The limiter 22 is preset with an upper limit value and a lower limit value for the output value of the converter 21 . Limiting unit 22 limits upper and lower limit values for the output value of converting unit 21 and outputs a voltage command value. The duty ratio conversion unit 26 converts the voltage command value into the duty ratio of the PWM command value based on a predetermined conversion map or formula, and outputs the duty ratio to the PWM generation unit 23 . The PWM generator 23 generates a PWM control signal to be output to the motor 5 based on the PWM command value output from the duty ratio converter 26 .

Motor 5 is driven by a PWM control signal output from motor driver 20 . L shown in FIG. 3 indicates the inductor component of the windings of the motor 5 and R indicates the resistance component of the windings of the motor 5 .

The position adjusting mechanism 4 is applied with a motor driving force Fm obtained by multiplying the actual current value Iact of the motor 5 by a predetermined coefficient K, and a load Fh detected by the load sensor 7 . The coefficient K is a constant determined by the torque constant and specific stroke of the motor 5, and is stored in the ROM 1002, for example.

Assuming that the mass of the inertial system including the position adjustment mechanism 4 is M and the coefficient of viscosity is D, the following relational expression (1) is obtained from Newton's equation of motion.

M(d ² x/dt ² )=−D(dx/dt)+Fm+Fh (1)

The above formula (1) can be transformed into the following formula (2).

Fh=M(d ² x/dt ² )+D(dx/dt)−Fm (2)

By Laplace transforming the above equation (2), the following equation (3) is obtained.

Fh(s)=(Ms ² +Ds)×X(s)−Fm(s) (3)

From the above equation (3), the movement amount X(s)=Xact of the steering wheel 1 is expressed by the following equation (4).

X(s)=Xact=(Fm(s)+Fh(s))/(Ms ² +Ds) (4)

FIG. 4 is a diagram showing a first example of a speed conversion map of the vehicle steering column device according to the first embodiment.

In FIG. 4, the horizontal axis indicates the load Fh applied to the steering wheel 1, and the vertical axis indicates the target speed Vref. In the first example of the speed conversion map shown in FIG. 4, the first value Fh_Pull_th1 for the pull direction load Fh_Pull is equal to the first value Fh_Pull_th1 for the push direction load Fh_Push. In the example shown in FIG. 4, the second value Fh_Pull_th2 for the pull direction load Fh_Pull is equal to the second value Fh_Pull_th2 for the push direction load Fh_Push. Here, a telescopic mechanism for moving the steering wheel 1 in the front-rear direction (the direction indicated by the solid line arrow in FIG. 1) will be described.

In the present disclosure, the target speed Vref is zero in the first region where the push direction load Fh_Push is less than the first value Fh_Push_th1. In addition, the target speed Vref is zero in the first region where the pull-direction load Fh_Pull is less than the first value Fh_Pull_th1. In other words, a first region in which the load Fh_Push in the push direction is less than the first value Fh_Push_th1 and a first region in which the load Fh_Pull in the pull direction is less than the first value Fh_Pull_th1 are defined as dead zone regions. The steering wheel 1 does not move in this first area (dead zone area).

Further, in the present disclosure, the target speed Vref_Push is constant at the target speed limit value Vref_Push_lim in the third region where the push direction load Fh_Push is equal to or greater than the second value Fh_Push_th2 larger than the first value Fh_Push_th1. In the third region where the pull direction load Fh_Pull is equal to or greater than the second value Fh_Pull_th2 larger than the first value Fh_Pull_th1, the target speed Vref_Pull is constant at the target speed limit value Vref_Pull_lim. In other words, the third region where the push direction load Fh_Push is equal to or greater than the second value Fh_Push_th2 is defined as the limit region where the target speed Vref_Push is constant at the target speed limit value Vref_Push_lim. A third region in which the pull-direction load Fh_Pull is equal to or greater than the second value Fh_Pull_th2 is defined as a restriction region in which the target speed Vref_Pull is constant at the target speed limit value Vref_Pull_lim. In this third area (restricted area), the steering wheel 1 moves at a constant speed. In this way, by providing a limit region for the push direction load Fh_Push and the pull direction load Fh_Pull, the target It is possible to prevent the speed Vref_Push from becoming larger than the target speed limit value Vref_Push_lim. In addition, it is possible to prevent the target speed Vref_Pull from becoming larger than the target speed limit value Vref_Pull_lim in the third region (restricted region) where the pull direction load Fh_Pull is equal to or greater than the second value Fh_Pull_th2.

In the example shown in FIG. 4, in the second region where the push-direction load Fh_Push is greater than or equal to the first value Fh_Push_th1 and less than the second value Fh_Push_th2, the target speed Vref_Push increases with a predetermined slope as the push-direction load Fh_Push increases. Become. In other words, the second region in which the pushing direction load Fh_Push is greater than or equal to the first value Fh_Push_th1 and less than the second value Fh_Push_th2 is the transition region in which the target speed Vref_Push increases with a predetermined slope as the pushing direction load Fh_Push increases. and In the second region where the pull direction load Fh_Pull is equal to or greater than the first value Fh_Pull_th1 and less than the second value Fh_Pull_th2, the target speed Vref_Pull increases at a predetermined slope as the pull direction load Fh_Pull increases. In other words, the second region in which the pull-direction load Fh_Pull is greater than or equal to the first value Fh_Pull_th1 and less than the second value Fh_Pull_th2 is the transition region in which the target speed Vref_Pull increases at a predetermined slope as the pull-direction load Fh_Pull increases. and That is, in the example shown in FIG. 4, in the second region (transition region), the target speed Vref_Push increases linearly as the push direction load Fh_Push increases, and the target speed Vref_Push increases as the pull direction load Fh_Pull increases. Velocity Vref_Pull increases linearly.

In the present disclosure, as shown in FIG. 4, by providing a dead zone region for the load Fh_Push in the push direction and the load Fh_Pull in the pull direction, for example, malfunction due to steering operation, road noise during driving, etc. Malfunction due to vibration can be prevented.

In addition, the driver intentionally activates the telescopic mechanism (position adjusting mechanism 4) by applying a push-direction load Fh_Push equal to or greater than the first value Fh_Push_th1 or applying a pull-direction load Fh_Pull equal to or greater than the first value Fh_Pull_th1. can be operated. As a result, when the driver feels uncomfortable with the steering position while driving, the position of the steering wheel 1 can be adjusted intuitively without requiring an additional operation such as operating the adjustment start switch.

FIG. 5 is a diagram showing a second example of the speed conversion map of the vehicle steering column device according to the first embodiment.

In the example shown in FIG. 5, in the second region (transition region), the slope of the target speed Vref_Push increases as the load Fh_Push in the pushing direction increases. In addition, the slope of the target speed Vref_Push increases as the pull-direction load Fh_Pull increases. In other words, in the second region (transition region), the target speed Vref_Push increases nonlinearly as the push direction load Fh_Push increases, and the target speed Vref_Pull increases nonlinearly as the pull direction load Fh_Pull increases. To increase. Specifically, in the second region (transition region), as shown in FIG. 5 , when the load Fh_Push in the pushing direction becomes equal to or greater than the first value Fh_Push_th1, the target speed Vref_Push is gradually reduced in accordance with the increase in the load Fh_Push in the pushing direction. Increases rate of increase. When the pull-direction load Fh_Pull becomes equal to or greater than the first value Fh_Push_th1, the increase rate of the target speed Vref_Pull gradually increases as the pull-direction load Fh_Pull increases. As a result, the optimum steering position can be obtained without paying attention to the boundaries (first values Fh_Push_th1, Fh_Pull_th1) between the first region (dead band region) and the second region (transition region).

FIG. 6 is a diagram showing a third example of the speed conversion map of the vehicle steering column device according to the first embodiment.

In the example shown in FIG. 6, in the second region (transition region), the slopes of the target speeds Vref_Push and Vref_Pull are changed according to predetermined conditions.

For example, the slopes of the target speeds Vref_Push and Vref_Pull may be changed according to the vehicle speed S output from the vehicle speed sensor 6 . Specifically, for example, as the vehicle speed S increases, the slopes of the target speeds Vref_Push and Vref_Pull may be made smaller.

Further, for example, the slopes of the target speeds Vref_Push and Vref_Pull may be changed according to the time rate of change (time differential value) of the load Fh. Specifically, for example, the gradients of the target speeds Vref_Push and Vref_Pull may be increased as the time rate of change (time differential value) of the load Fh increases.

7A, 7B, and 7C are timing charts showing a first example of changing the slope of the target speed in the second region. FIG. 7A shows the time transition of the load Fh, FIG. 7B shows the time transition of the value dFh/dt obtained by time-differentiating the load Fh, and FIG. 7C shows the time transition of the target speed Vref. A dashed line shown in FIG. 7C indicates the target speed Vref when the first example of the speed conversion map shown in FIG. 4 is applied. In the examples shown in FIGS. 7A, 7B, and 7C, the threshold dFh/dt_th for the time differential value dFh/dt of the load Fh is stored in the ROM 1002, for example. Note that in FIGS. 7A, 7B, and 7C, the first values Fh_Push_th1 and Fh_Pull_th1 are the first value Fh_th1.

In the first example shown in FIGS. 7A, 7B, and 7C, when the time-differentiated value dFh/dt of the load Fh becomes equal to or greater than the threshold value dFh/dt_th, the slope of the target speed Vref is changed, and the load Fh becomes the first Maintain the modified slope until it is less than the values Fh_Push_th1, Fh_Pull_th1. Specifically, FIGS. 7A, 7B, and 7C show examples in which the time differential value dFh/dt of the load Fh is greater than or equal to the threshold value dFh/dt_th at time t1. In this case, at time t1 when the time differential value dFh/dt of the load Fh becomes equal to or greater than the threshold value dFh/dt_th, the slope of the target speed Vref is changed, and until time t2 when the load Fh becomes less than the first values Fh_Push_th1 and Fh_Pull_th1, During period T, the modified slope is maintained. As a result, during a period T from time t1 when the time differential value dFh/dt of the load Fh becomes equal to or greater than the threshold value dFh/dt_th to time t2 when the load Fh is less than the first values Fh_Push_th1 and Fh_Pull_th1, the target speed Vref is: As indicated by the solid line, it is higher than the target speed Vref when the first example (FIG. 4) of the speed conversion map indicated by the dashed line is applied.

Further, for example, when the load Fh exceeds a predetermined threshold value twice consecutively within a predetermined period, the slopes of the target speeds Vref_Push and Vref_Pull may be changed. Specifically, for example, when the load Fh exceeds a predetermined threshold value twice consecutively within a predetermined period, the gradients of the target speeds Vref_Push and Vref_Pull may be increased.

8A and 8B are timing charts showing a second example of changing the slope of the target speed in the second region. FIG. 8A shows the time transition of the load Fh, and FIG. 8B shows the time transition of the target speed Vref. A dashed line shown in FIG. 8B indicates the target speed Vref when the first example of the speed conversion map shown in FIG. 4 is applied. In the example shown in FIGS. 8A and 8B, the threshold Fh_th for the load Fh and the period Tth during which it is determined that the load Fh has continuously exceeded the threshold Fh_th are stored in the ROM 1002, for example. The threshold Fh_th for the load Fh may be equal to the first values Fh_Push_th1 and Fh_Pull_th1 described above. Note that in FIGS. 8A and 8B, the first values Fh_Push_th1 and Fh_Pull_th1 are the first value Fh_th1.

In the second example shown in FIGS. 8A and 8B, when the period from when the load Fh becomes equal to or greater than the threshold Fh_th to when the load Fh next becomes equal to or greater than the threshold Fh_th is equal to or less than the period Tth, the slope of the target speed Vref is is changed, and the changed slope is maintained until the load Fh becomes less than the threshold value Fh_th. Specifically, in the examples shown in FIGS. 8A and 8B, the period T1 from time t1 when the load Fh becomes equal to or greater than the threshold Fh_th to time t2 when the load Fh next becomes equal to or greater than the threshold Fh_th is longer than the period Tth. Large (T1>Tth). In this case, the slope of the target speed Vref is not changed. In the example shown in FIGS. 8A and 8B, a period T3 from time t2 when the load Fh becomes equal to or greater than the threshold Fh_th to time t3 when the load Fh next becomes equal to or greater than the threshold Fh_th is equal to or shorter than the period Tth. (T2≦Tth). In this case, the slope of the target speed Vref is changed at time t3, and the changed slope is maintained for a period t3 until time t4 when the load Fh becomes less than the threshold value Fh_th. As a result, in a period T3 from time t3 when the load Fh becomes equal to or greater than the threshold value Fh_th to time t4 when the load Fh is less than the first value Fh_th1, the target speed Vref changes as indicated by the solid line and the speed conversion indicated by the dashed line. It is greater than the target speed Vref when the first example of the map (FIG. 4) is applied.

FIG. 9 is a diagram showing a third example of the speed conversion map of the vehicle steering column device according to the first embodiment.

In the example shown in FIG. 9, in the second region (transition region), the target speed limit values Vref_Push_lim and Vref_Pull_lim are changed according to predetermined conditions.

For example, the target speed limit values Vref_Push_lim and Vref_Pull_lim may be changed according to the vehicle speed S output from the vehicle speed sensor 6 . Specifically, for example, as the vehicle speed S increases, the target speed limit values Vref_Push_lim and Vref_Pull_lim may be decreased.

Further, for example, the target speed limit values Vref_Push_lim and Vref_Pull_lim may be changed according to the time rate of change (time differential value) of the load Fh. Specifically, for example, the target speed limit values Vref_Push_lim and Vref_Pull_lim may be increased as the time rate of change (time differential value) of the load Fh increases.

Further, for example, the target speed limit values Vref_Push_lim and Vref_Pull_lim may be changed when the load Fh exceeds a predetermined threshold value twice consecutively within a predetermined period. Specifically, for example, the target speed limit values Vref_Push_lim and Vref_Pull_lim may be increased when the load Fh exceeds a predetermined threshold value twice consecutively within a predetermined period.

FIG. 10 is a diagram showing a fourth example of the speed conversion map of the vehicle steering column device according to the first embodiment. In FIG. 10, the broken line shown in the third quadrant is the same as the third quadrant of the first example of the speed conversion map (FIG. 4). That is, the first value Fh_Pull_th1 for the pull-direction load Fh_Pull on the broken line shown in the third quadrant is equal to the first value Fh_Push_th1 for the push-direction load Fh_Push on the solid line shown in the first quadrant. Also, the second value Fh_Pull_th2 for the pull-direction load Fh_Pull on the dashed line shown in the third quadrant is equal to the second value Fh_Push_th2 for the push-direction load Fh_Push on the solid line shown in the first quadrant.

In a telescopic mechanism that moves the steering wheel 1 in the front-rear direction (the direction indicated by the solid arrow in FIG. 1), the pull-direction load Fh_Pull tends to be smaller than the push-direction load Fh_Push. For this reason, for example, as shown in FIG. 10, it is desirable that the first value Fh_Pull_th1 for the pull direction load Fh_Pull be smaller than the first value Fh_Push_th1 for the push direction load Fh_Push. Specifically, in the example shown in FIG. 10, the first value Fh_Pull_th1 for the pulling direction load Fh_Pull on the solid line shown in the third quadrant is set to It is smaller than the first value Fh_Pull_th1 for Fh_Pull. Similarly, it is desirable to make the second value Fh_Pull_th2 for the pull direction load Fh_Pull smaller than the second value Fh_Push_th2 for the push direction load Fh_Push. Specifically, in the example shown in FIG. 10, the second value Fh_Pull_th2 for the pull-direction load Fh_Pull on the solid line shown in the third quadrant is set to It is smaller than the second value Fh_Pull_th2 for Fh_Pull. This makes it possible to reduce the first area (dead zone area) in the pulling direction, where the load tends to be small.

In the first, second, third, and fourth examples of the speed conversion maps shown in FIGS. 4, 5, 6, 9, and 10, the steering wheel 1 is moved forward and backward (in the direction of the solid arrow in FIG. 1). Although the telescopic mechanism for moving the steering wheel 1 has been described, it can also be applied to a tilt mechanism for moving the steering wheel 1 in the vertical direction (in the direction indicated by the dashed arrow in FIG. 1). Here, in contrast to the fourth example shown in FIG. 10, which describes a telescopic mechanism for moving the steering wheel 1 in the front-rear direction (the direction indicated by the solid line arrow in FIG. 1), the steering wheel 1 is moved in the vertical direction (the direction indicated by the broken line arrow in FIG. 1). The tilting mechanism for moving in the indicated direction) will be described.

FIG. 11 is a diagram showing a fifth example of the speed conversion map of the vehicle steering column device according to the first embodiment. In FIG. 11, the broken line shown in the third quadrant corresponds to the broken line shown in the third quadrant of the fourth example of the velocity conversion map (FIG. 10). That is, the first value Fh_Up_th1 for the upward load Fh_Up on the dashed line virtually shown in the third quadrant is equal to the first value Fh_Down_th1 for the downward load Fh_Down on the solid line shown in the first quadrant. Also, the second value Fh_Up_th2 for the upward load Fh_Up on the broken line virtually shown in the third quadrant is equal to the second value Fh_Down_th2 for the downward load Fh_Down on the solid line shown in the first quadrant.

In a tilt mechanism that moves the steering wheel 1 vertically (in the direction indicated by the dashed arrow in FIG. 1), the upward load Fh_Up tends to be smaller than the downward load Fh_Down. For this reason, for example, as shown in FIG. 11, it is desirable that the first value Fh_Up_th1 for the load Fh_Up in the upward direction is smaller than the first value Fh_Down_th1 for the load Fh_Down in the downward direction. Specifically, in the example shown in FIG. 11, the first value Fh_Up_th1 for the upward load Fh_Up on the solid line shown in the third quadrant is the first value Fh_Down_th1 for the downward load Fh_Down on the solid line shown in the first quadrant. It is smaller than the virtual first value Fh_Up_th1 for the upward load Fh_Up on the equal dashed line. Similarly, it is desirable that the second value Fh_Up_th2 for the upward load Fh_Up is smaller than the second value Fh_Down_th2 for the downward load Fh_Down. Specifically, in the example shown in FIG. 11, the second value Fh_Up_th2 for the upward load Fh_Up on the solid line shown in the third quadrant is the second value Fh_Down_th2 for the downward load Fh_Down on the solid line shown in the first quadrant. It is smaller than the virtual second value Fh_Up_th2 for the upward load Fh_Up on the equal dashed line. This makes it possible to reduce the first area (dead zone area) in the lifting direction where the load tends to be small.

As described above, the vehicle steering column device 100 according to the first embodiment provides a dead zone region with respect to the load Fh, thereby preventing, for example, malfunction due to steering operation or due to minute vibration such as road noise while driving. can be prevented.

Also, the driver can intentionally operate the position adjusting mechanism 4 by applying a load Fh equal to or greater than the first value Fh_th1. As a result, when the driver feels uncomfortable with the steering position while driving, the position of the steering wheel 1 can be adjusted intuitively without requiring an additional operation such as operating the adjustment start switch.

(Embodiment 2)
FIG. 12 is a diagram showing an example of a control system of the vehicle steering column device according to the second embodiment. In addition, the same code|symbol is attached|subjected to the structure which has the same function as Embodiment 1 mentioned above, and description is abbreviate|omitted.

The ECU 10a further includes a phase lead compensator 12 as an internal block configuration. As a result, the response speed of the position adjusting mechanism 4 to the input of the load Fh to the target speed generator 11 can be improved. It can work smoothly.

(Embodiment 3)
FIG. 13 is a diagram showing an example of a control system of the vehicle steering column device according to the third embodiment. In addition, the same code|symbol is attached|subjected to the structure which has the same function as Embodiment 1, 2 mentioned above, and description is abbreviate|omitted.

The ECU 10a further includes a friction compensator 15 as an internal block configuration. As a result, it is possible to prevent the smooth movement of the steering wheel 1 from being hindered by the friction of the drive components of the vehicle steering column device 100 .

FIG. 14 is a diagram showing an example of a friction compensator. As shown in FIG. 14, the friction compensator 15 of the ECU 10b removes the high-frequency component of the target speed Vref output from the target speed generator 11, and uses the current conversion map shown in the figure to calculate the compressed current command value. Iref_comp is generated, multiplied by a predetermined gain G, and added to the output of the conversion unit 14 . A current conversion map is stored in the ROM 1002, for example. Note that the friction compensator 15 may be configured to calculate the compression current command value Iref_comp using, for example, a formula stored in the ROM 1002 without using the current conversion map. The formula for calculating the compression current command value Iref_comp may be, for example, as shown in the following formulas (5) and (6), as long as it converges when the target speed Vref is infinitely changed. Thereby, the friction of the inertial system including the motor 5 and the position adjustment mechanism 4 can be compensated.

Iref_comp=arctan(Vref) (5)

Iref_comp=tanh(Vref) (6)

Note that the diagrams used above are conceptual diagrams for qualitatively explaining the present disclosure, and are not limited to these. In addition, although the above-described embodiment is an example of the preferred implementation of the present disclosure, it is not limited to this, and various modifications can be implemented without departing from the gist of the present disclosure.

REFERENCE SIGNS LIST 1 steering wheel 2 steering shaft 3 steering column 4 position adjusting mechanism 5 motor 6 vehicle speed sensor 7 load sensor 10, 10a, 10b control unit (ECU)
REFERENCE SIGNS LIST 11 target speed generator 12 phase lead compensator 13 converter 14 converter 15 friction compensator 16 limiter 20 motor driver 21 converter 22 limiter 23 PWM generator 100 vehicle steering column device

Claims (14)

a load sensor that detects the load applied to the steering wheel;
a position adjusting mechanism that moves the steering wheel in at least one of the front-back direction and the up-down direction according to the load;
an actuator that drives the position adjustment mechanism;
a control unit that generates a target current value to be supplied to the actuator based on the load and the amount of movement of the steering wheel;
a driving unit that drives and controls the actuator based on the target current value;
with
The control unit
controlling the movement speed of the steering wheel to be zero in a first region where the load is less than a first value;
In a second region where the load is greater than or equal to the first value and less than a second value larger than the first value, the moving speed is controlled to increase as the load increases. ,
Vehicle steering column device. The control unit
In the second region, control is performed so that the movement speed increases with a predetermined slope in accordance with the increase in the load.
The steering column device for a vehicle according to claim 1. The control unit
In the second region, control is performed so that the slope of the moving speed increases as the load increases.
The steering column device for a vehicle according to claim 1. The control unit
In the second region, as the vehicle speed increases, the slope of the movement speed is controlled to decrease;
The vehicle steering column device according to claim 2 or 3. The control unit
In the second region, control is performed so that the slope of the movement speed increases as the time rate of change of the load increases.
The vehicle steering column device according to claim 2 or 3. The control unit
When the load exceeds a predetermined threshold value twice consecutively within a predetermined period of time, control is performed so that the slope of the movement speed increases in the second region.
The vehicle steering column device according to claim 2 or 3. The control unit
In a third region where the load is equal to or greater than the second value, the movement speed is controlled to be a constant movement speed limit value.
The vehicle steering column device according to any one of claims 1 to 6. The control unit
Control so that the movement speed limit value becomes smaller as the vehicle speed increases;
The vehicle steering column device according to claim 7. The control unit
controlling the movement speed limit value to increase as the time rate of change of the load increases;
The vehicle steering column device according to claim 7. The control unit
controlling the movement speed limit value to increase when the load exceeds a predetermined value consecutively twice within a predetermined period;
The vehicle steering column device according to claim 7. The position adjustment mechanism is a telescopic mechanism that moves the steering wheel in the front-rear direction by the driving force of the actuator,
The control unit
controlling such that the first value for the load in the pull direction is smaller than the first value for the load in the push direction;
The vehicle steering column device according to any one of claims 1 to 10. The position adjustment mechanism is a tilt mechanism that vertically moves the steering wheel by the driving force of the actuator,
The control unit
Control so that the first value for the load in the upward direction is smaller than the first value for the load in the downward direction;
The vehicle steering column device according to any one of claims 1 to 10. The control unit
Further comprising a phase lead compensator for the input of the load,
The vehicle steering column device according to any one of claims 1 to 12. The control unit
further comprising a friction compensator that compensates for friction of an inertial system including the actuator and the position adjustment mechanism;
The vehicle steering column device according to any one of claims 1 to 13.

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