KR20150077988A - Control device for MDPS and control method for MDPS using of the same - Google Patents

Abstract

The present invention relates to an MDPS control device for controlling an MDPS for controlling an MDPS by obtaining a torque input to an actual MDPS in consideration of a driver input torque for operating a steering wheel and a steering wheel inertial torque generated by a steering inertia of the steering wheel, And an MDPS control method using the same.
The MDPS controller according to the present invention calculates the driver input torque T (k) by the product of the twist angle of the torsion bar 23 provided on the column 22 connected to the steering wheel 21 and the twist constant k of the torsion bar 23 _d) the calculated driver's input torque calculating section 11, a steering wheel by the steering wheel rotational mass moment of inertia and as the product of the angular acceleration of the steering wheel 21 in the rotational inertia of the steering wheel inertia torque (T _SW And an MDPS input torque T _in which is a torque actually input to the MDPS by adding the driver input torque T _d and the steering wheel inertial torque T _SW to the steering wheel inertia torque calculation unit 12, and obtaining MDPS input torque computing section 13, the MDPS and input torque comprises a MDPS output torque calculating unit 14 for calculating the MDPS output torque (T _out) output from the MDPS proportional to (T _in), it To control the MDPS.

Description

Technical Field [0001] The present invention relates to an MDPS control apparatus and an MDPS control method using the same,

The present invention relates to an MDPS of a vehicle, and more particularly, to an MDPS of a vehicle, and more particularly, to an MDPS of a vehicle, which uses a torque actually input to the MDPS in consideration of a steering input torque at which a driver manipulates the steering wheel and a steering wheel inertial torque And an MDPS control method using the same.

In recent years, a motor driven power steering system (MDPS), which assists a driver's assist force by using a motor, has been widely applied.

In the MDPS, a torque sensor is installed in a torsion bar provided on a column connected to a steering wheel, and an assist torque proportional to a driving force of a driver is generated by using a motor, thereby assisting a driving force of a driver.

The MDPS calculates an operator input torque generated as the driver operates the steering wheel, and then generates an assist torque proportional to the driver input torque. Here, the driver input torque can be expressed as a product of a twist angle of a torsion bar installed on the MDPS and a twist constant of the torsion bar (driver input torque = torsion bar twist angle x torsion bar torsion constant) The torque to be outputted from the MDPS is generated in the motor in proportion to the input torque input to the MDPS.

However, according to the related art as described above, the torque inputted to the MDPS at the time of steering is larger than the driver input torque recognized by the MDPS, and the driver feels a sense of heterogeneity at the time of steering. That is, when the driver manipulates the steering wheel, not only the torque input by the driver but also the torque generated by the rotational inertia of the rotating steering wheel acts, which is not taken into account and is thus incorrectly controlled in the control of the MDPS.

That is, in the conventional MDPS control, since the MDPS is controlled by considering only the driver input torque, if the driver steers the steering wheel rapidly, the weight of the steering wheel suddenly changes according to the vehicle speed, There is a problem.

The following prior art document relates to an apparatus and method for selecting a steering force of a vehicle, and discloses a technique for allowing a driver to select a steering force mode of a steering apparatus to feel a desired steering feeling.

KR 10-2012-0134542A

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a steering angle control system, So that the weight of the steering wheel is not changed according to the vehicle speed even when the driver steers at a high speed, and an MDPS control method using the MDPS control device.

According to an aspect of the present invention, there is provided an MDPS control apparatus including a driver input torque calculation unit calculating a driver input torque by a product of a twist angle of a torsion bar installed on a column connected to a steering wheel and a torsional constant of the torsion bar, A steering wheel inertial torque calculation unit for calculating a steering wheel inertial torque by a rotational inertia of the steering wheel as a product of a mass inertial moment of the steering wheel rotating and an angular acceleration of the steering wheel; An MDPS input torque calculation unit for calculating an MDPS input torque that is a torque actually input to the MDPS by adding the torque to the MDPS input torque and an MDPS output torque calculation unit for calculating an MDPS output torque output from the MDPS proportional to the MDPS input torque.

The driver input torque calculation unit receives a twist angle measured from a torque sensor of a torsion bar installed on a column connected to a steering wheel.

Wherein the twist angle is a difference between a rotation angle of the steering wheel and a rotation angle of the column.

Wherein the steering wheel inertial torque calculation unit calculates the angular acceleration of the steering wheel from the steering angle inputted from the steering angle sensor provided on the steering wheel.

Meanwhile, the MDPS control method according to the present invention includes: a driver input torque calculation step of calculating a driver input torque used by the driver to operate the steering wheel to operate the steering wheel when the driver rotates the steering wheel; A steering wheel inertial torque calculation step of calculating a steering wheel inertial torque generated by the rotation of the steering wheel when the operation of the steering wheel is operated; And an MDPS output torque calculating step of calculating an MDPS output torque proportional to the MDPS input torque by multiplying the MDPS input torque by a constant determined by the MDPS input torque calculating step.

Wherein the driver input torque calculation step calculates the driver input torque by multiplying the twist angle of the torsion bar provided on the column connected to the steering wheel by the torsional constant of the torsion bar.

Wherein the twist angle is a difference between a rotation angle of the steering wheel and a rotation angle of the column

Wherein the steering wheel inertial torque calculating step calculates the steering wheel inertial torque by multiplying the angular acceleration obtained from the steering angle sensor provided on the steering wheel by the rotational inertia moment of the steering wheel.

According to the MDPS control apparatus and the MDPS control method using the MDPS controller according to the present invention, when the driver manipulates the MDPS, the driver inputs the driver's input torque and the moment of inertia of the motor and the steering wheel The MDPS is controlled using the MDPS input torque input to the actual MDPS in consideration of the generated torque so that the driver does not suddenly change the weight of the steering wheel even if the driver operates the steering wheel rapidly. Regardless of whether you feel a certain weight.

1 is a simplified view of an MDPS system;
2 is a block diagram illustrating an MDPS controller according to the present invention;
3 is a flow chart illustrating an MDPS control method in accordance with the present invention.
4 is a graph showing MDPS output torque calculated in accordance with the present invention;

Hereinafter, an MDPS controller according to the present invention will be described in detail with reference to the accompanying drawings.

The MDPS controller according to the present invention calculates the driver input torque T (k) by the product of the twist angle of the torsion bar 23 provided on the column 22 connected to the steering wheel 21 and the twist constant k of the torsion bar 23 _d) the calculated driver's input torque calculating section 11, a steering wheel by the steering wheel rotational mass moment of inertia and as the product of the angular acceleration of the steering wheel 21 to the inertia of the steering wheel inertia torque (T _SW) An MDPS input torque T _in which an MDPS input torque T _in input to the actual MDPS is obtained by summing the driver input torque T _d and the steering wheel inertial torque T _SW , And an MDPS output torque calculating section 14 for calculating an MDPS output torque T _out output from the MDPS 20 proportional to the MDPS input torque T _in .

과 상기 토션바(23)의 비틀림 상수(k)를 곱하여 구한 운전자 입력토크(T_d)는 다음과 같다.The driver's input torque calculation section 11 measures the twist angle of the torsion bar 23 by the torque sensor 24 provided on the column 22 connected to the steering wheel 21 and outputs the torque inputted from the driver to the steering wheel 21 That is, the driver input torque T _d . The steering wheel 21 is connected to the column 22 and the column 22 is provided with a torsion bar 23 which is twisted when the driver operates the steering wheel 21. [ When the steering wheel 21 rotates and is twisted with the torsion bar 23, the ratio of the torsion bar 23 to the driver's torque T _d input from the driver to the steering wheel 21 using the rim angle, . That is, the twist angle of the torsion bar 23

And the torsion bar driver calculated by multiplying the torsion constant (k) of (23) the input torque (T _d) is as follows.

Here, since the twist angle is a relative twist between the steering wheel 21 and the column 22, the twist angle is represented by the difference between the steering wheel rotation angle and the column rotation angle.

의 곱으로부터 상기 조향휠 관성토크(T_SW)를 구한다(

). 여기서, 조향휠(21)의 회전각속도는 조향휠에 설치된 조향각센서(25)로부터 구해지는데, 상기 조향각센서(25)로부터 구해진 조향각을 시간에 대해 미분하여 계산될 수 있다.The steering wheel inertial torque calculation section 12 calculates the torque generated by the moment of inertia of the steering wheel 21, that is, the steering wheel inertial torque T _SW , which is rotated by the driver's operation while having a mass. For this, the steering wheel inertial torque calculation unit 12 calculates the mass inertia moment J, which is determined by the dimension and mass of the steering wheel 21,

The steering wheel inertial torque T _SW is obtained

). Here, the rotational angular velocity of the steering wheel 21 is obtained from the steering angle sensor 25 provided on the steering wheel, and can be calculated by differentiating the steering angle obtained from the steering angle sensor 25 with respect to time.

The MDPS input torque calculation section 13 calculates the MDPS input torque Tq of the steering wheel 21 based on the driver input torque T _d inputted by the driver when the steering wheel 21 is rotated and the mass inertia moment J of the steering wheel 21, The inertia torque T _SW is added to obtain the MDPS input torque T _in substantially input to the MDPS. The MDPS assists the driving force of the driver by exerting the MDPS output torque T _out proportional to the input torque. In the prior art, the torque input to the MDPS 20 is input to the MDPS only by the steering of the driver There is a problem that the torque generated by the rotation of the steering wheel 21 having a mass is not taken into consideration and the feeling of heterogeneity is felt at the time of fast steering.

In order to solve the above problem, the input torque T _in input to the MDPS obtained by taking into consideration the rotational inertia of the steering wheel 21 can be expressed by the following equation.

If the driver slowly turns the steering wheel 21, the inertial torque (T _SW ) component of the steering wheel is insignificant, so that the driver inputs the driver input torque T _d steering the steering wheel and the MDPS input torque T _in) it is, but a large difference, the driver is quickly turning when a loose increases the angular acceleration of the steering wheel (21) to override the component of the rotating steering wheel inertia torque (T _SW) by the steering wheel 21 to steering wheel Can not.

Therefore, the MDPS input torque calculation unit 13 obtains the MDPS input torque T _in that is input to the actual MDPS by adding the driver input torque T _d and the steering wheel inertial torque T _SW .

The MDPS output torque calculation section 14 calculates an MDPS output torque T _out proportional to the MDPS input torque T _in obtained by the MDPS input torque calculation section 13. [ The ECU stores torque outputted to control the MDPS according to the conditions of the vehicle speed, the MDPS input torque T _in , etc. _in the form of a map, an equation, etc. The MDPS output torque calculation unit 14 calculates the vehicle speed, MDPS according to the input torque (T _in) and calculates the MDPS torque output (T _out) which is proportional to the MDPS input torque (T _in).

When the MDPS output torque T _out is calculated by the MDPS output torque calculation unit 14, the MDPS output torque T _out is output to the MDPS and the MDPS is controlled so that the MDPS output torque T _out is displayed.

Hereinafter, an MDPS control method according to the present invention will be described.

The MDPS control method according to the present invention calculates the driver input torque T _d used by the driver to operate the steering wheel 21 to operate the steering wheel 21 when the driver rotates the steering wheel A steering wheel inertia torque calculation step S120 for calculating a steering wheel inertial torque T _SW generated by the rotation of the steering wheel 21 when the operation of the steering wheel is operated, An MDPS input torque calculating step (S130) of obtaining an MDPS input torque (T _in ) as a torque input to the actual MDPS by summing the driver input torque (T _d ) and the steering wheel inertial torque (T _SW ) and a MDPS output torque calculation step (S140) for calculating a MDPS output torque (T _out), which is multiplied by the predetermined constant to the MDPS input torque (T _in) is proportional to the MDPS input torque (T _in).

When the driver steers the steering wheel 21 for steering, the driver input torque calculating step S110 calculates the driver input torque T inputted to the steering wheel 21 to operate the steering wheel 21 _d ). In the driver input torque calculation step (S110), a twist angle of the torsion bar (23) installed on the column (22) connected to the steering wheel (21) is used. That is, the driver input torque T _d input to the steering wheel 21 is calculated by multiplying the twist angle of the torsion bar 23 by the twist constant of the torsion bar.

)와 곱해진 성분이 상기 MDPS로 입력되는 조향휠 관성토크(T_SW)가 된다.Steering Wheel Inertia Torque Calculation Step S120 causes the steering wheel 21 with mass to rotate to generate an inertia moment when the driver rotates the steering wheel 21 for steering, As shown in Fig. The steering wheel inertial torque T _SW generated by the rotation of the steering wheel 21 is not considered in the related art. However, in the present invention, the steering wheel inertial torque T _SW ), It is possible to control the MDPS more precisely. Since the steering wheel is a mass having a predetermined dimension, an inertial moment is generated by the rotation, and the angular velocity of the steering wheel 21

) Is a steering wheel inertial torque (T _SW ) input to the MDPS.

The MDPS input torque calculation step S130 is a step of calculating an MDPS input torque of the steering wheel based on the driver input torque T _d calculated in the driver input torque calculation step S110 and the steering wheel inertial torque T _SW calculated in the steering wheel inertial torque calculation step S120 In sum, the MDPS input torque (T _in ) input to the MDPS is calculated.

In particular, among the MDPS input torque T _in , when the steering wheel is slowly operated, the component of the steering wheel inertial torque T _SW due to the angular acceleration of the steering wheel is small. However, The steering wheel inertial torque (T _SW ) component becomes large, so that the MDPS input torque T _in input to the MDPS becomes different. Therefore, in the MDPS input torque calculation step S130, the driver input torque T _d and the steering wheel inertial torque T _SW are summed to calculate the MDPS input torque T _in input to the actual MDPS, The input MDPS input torque (T _in ) is calculated.

: 토션바의 비틀림각, J : 조향휠의 회전관성모멘트,

:조향휠의 각가속도)(k: torsion constant of the torsion bar,

: Torsion angle of the torsion bar, J: rotational inertia moment of the steering wheel,

: Angular acceleration of the steering wheel)

The MDPS output torque calculation step S140 calculates an MDPS output torque T _out to be outputted from the MDPS in proportion to the MDPS input torque T _in obtained in the MDPS input torque calculation step S130. MDPS is a MDPS output torque (T _out) according to the MDPS input torque (T _in) input to the MDPS vary, of course, is different according to the vehicle speed, MDPS output torque (T _out) by the other conditions are different values . Therefore, in the MDPS output torque calculation step S140, the MDPS output torque T _out to be output from the MDPS is calculated in consideration of the operating condition such as the vehicle speed and the MDPS input torque T _in . On the other hand, it is preferable that the MDPS output torque T _out with respect to the MDPS input torque T _in according to the condition of the vehicle is stored in the ECU as a map, an equation or the like.

According to the MDPS controller and the MDPS control method using the MDPS controller according to the present invention, when the driver operates the steering wheel 21 to steer the vehicle, the driver inputs the driver's input torque through the steering wheel 21 with T _d), it is possible to more precisely control the MDPS by considering that the steering wheel inertia torque (T _SW) generated while the rotation is the steering wheel (21) with a mass that is input to the MDPS.

In particular, when the driver quickly operates the steering wheel 21, the steering wheel inertial torque T _SW becomes large. If the steering wheel inertial torque T _SW is not taken into account, the driver feels a sense of heterogeneity in the steering operation. (T _SW ), the driver eliminates the sense of heterogeneity with respect to the weight of the steering wheel according to the vehicle speed.

In the graph shown in Fig. 4, the output torque is shown for the torque input to the MDPS at the specific vehicle speed V. In Fig. When used as the MDPS input torque without considering the inertia torque (T _SW) of the steering wheel input torque (T _d) of the driver has a T _{in _0} is input to the MDPS is output torque T _out of _{_0.} However, when the MDPS output torque T _out outputted from the MDPS with respect to the MDPS input torque T _in input to the actual MDPS reflecting the penetration torque T _{SW is} shown in the steering wheel, the torque input to the MDPS is T _in Since the increase in _{_0} as T _in, T _out with the greater torque output from the MDPS also in T _{out _0.}

Therefore, according to the MDPS control apparatus and the MDPS control method using the MDPS control apparatus according to the present invention, since the torque input to the actual MDPS becomes larger than the torque input to the steering wheel by the driver, the MDPS output torque to be output from the MDPS also changes Able to know.

11: driver input torque calculation unit 12: steering wheel inertial torque calculation unit
13: MDPS input torque calculation unit 14: MDPS output torque calculation unit
20: MDPS 21: steering wheel
22: Column 23: Torsion bar
24: torque sensor 25: steering angle sensor
S110: Driver input torque calculation step
S120: steering wheel inertia torque calculation step
S130: MDPS input torque calculation step
S140: MDPS output torque calculation step

Claims (8)

A driver input torque calculating unit for calculating a driver input torque by multiplying a twist angle of the torsion bar provided on a column connected to the steering wheel by a torsional constant of the torsion bar;
A steering wheel inertia torque calculation unit for calculating a steering wheel inertial torque by the rotational inertia of the steering wheel by a product of a mass inertia moment of the steering wheel rotating and an angular acceleration of the steering wheel;
An MDPS input torque calculation unit for calculating an MDPS input torque that is a torque actually input to the MDPS by adding the driver input torque and the steering wheel inertial torque;
And an MDPS output torque calculation unit for calculating an MDPS output torque output from the MDPS proportional to the MDPS input torque.
The method according to claim 1,
Wherein the driver input torque calculation unit receives a twist angle measured from a torque sensor of a torsion bar installed on a column connected to the steering wheel.
3. The method of claim 2,
Wherein the twist angle is a difference between a rotation angle of the steering wheel and a rotation angle of the column.
3. The method of claim 2,
Wherein the steering wheel inertial torque calculation unit calculates the angular acceleration of the steering wheel from the steering angle inputted from the steering angle sensor provided on the steering wheel.
A driver input torque calculating step of calculating a driver input torque used by the driver to operate the steering wheel to operate the steering wheel when the driver rotates the steering wheel;
A steering wheel inertia torque calculation step of calculating a steering wheel inertial torque generated by the rotation of the steering wheel when an operation of the steering wheel is operated,
An MDPS input torque calculating step of summing the driver input torque and the steering wheel inertial torque to obtain an MDPS input torque that is a torque input to an actual MDPS;
And an MDPS output torque calculation step of multiplying the MDPS input torque by a constant and calculating an MDPS output torque proportional to the MDPS input torque.
6. The method of claim 5,
Wherein the driver input torque is calculated by multiplying the twist angle of the torsion bar provided on the column connected to the steering wheel by the twist constant of the torsion bar.
The method according to claim 6,
Wherein the twist angle is a difference between a rotation angle of the steering wheel and a rotation angle of the column.
The method according to claim 6,
Wherein the steering wheel inertial torque calculating step calculates the steering wheel inertial torque by multiplying the angular acceleration obtained from the steering angle sensor provided on the steering wheel by the rotational inertia moment of the steering wheel.

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