KR20190016194A - Steering control device and method thereof - Google Patents

Abstract

The present invention relates to a steering control device and a method thereof, wherein the steering control device comprises: a torque sensor detecting torque generated by steering of a steering wheel; and a steering compensation unit determining increase and decrease progress of a torque value with torque from a torque sensor, determining whether a compensation assist current is provided to a steering motor in accordance with the increase and decrease progress of the torque value and a positive number or a negative number of the torque value, and determining a provided compensation assist current value. Therefore, an inclination of an assist current becomes zero to prevent a notch feel for a sense of difference of a driver to be prevented and for convenience of the driver to be improved.

Description

 STEERING CONTROL DEVICE AND METHOD THEREOF BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The embodiments relate to a steering control apparatus and method.

Generally, a vehicle is provided with an electronic power steering (EPS) so as to easily steer the steering wheel, and the EPS assists the steering force of the driver by using the turning force of the steering motor.

EPS is equipped with an electronic control unit (ECU) that controls the steering motor driving when the steering wheel is steered. The ECU receives signals from a steering angle sensor, a torque sensor, a vehicle speed sensor and an engine speed sensor, And provides it to the steering motor to adjust the steering feeling of the steering wheel. Accordingly, in the low-speed section, the assist current is increased to relatively lighten the steering feeling, and in the high-speed section, the assist current is reduced to make the steering feeling relatively heavy,

On the other hand, when the driver steers the steering wheel to the left and right during driving, the torque changes, and the assist current also changes with the change in torque, as shown in Fig.

However, when the torque is 0 N · m, the assist current also crosses around 0 A, and in particular, the slope of the assist current becomes small, resulting in a zero moment. If the slope of the assist current becomes smaller, the duration of the assist current becomes longer. When the slope of the assist current is 0, as shown in the diagram showing the relationship between the torque and the steering angle shown in FIG. 2, the torque is 0 N m, that is, the slope of the assist current is 0, Notch Feel) occurs. That is, when the steering wheel is steered, the driver feels an uneven steering force from the steering wheel.

In order to solve the above problems, the embodiments of the present invention provide a steering apparatus and a control method thereof for preventing notch generation.

One embodiment includes a torque sensor for sensing a torque generated by steering of a steering wheel; And determining whether the torque value is increased or decreased by using the torque from the torque sensor, and determining whether to provide a compensation assist current to the steering motor depending on whether the torque value is positive or negative, And a steering compensation unit for determining a compensation assist current value to be supplied to the steering control unit.

In another embodiment, the steering wheel; A steering motor for providing a steering force to the steering wheel; A torque sensor for sensing a torque generated by steering of the steering wheel; A steering angle velocity sensor for sensing a steering angle velocity of the steering wheel; And determining whether or not the torque value is a positive or negative value and providing a compensation assist current to the steering motor in accordance with the steering angle speed, And a steering compensation unit for determining a compensation assist current value to be provided.

In yet another embodiment, there is provided a method comprising: sensing a torque generated by steering of a steering wheel; Determining a change in the torque value using the torque; A compensation determination step of determining whether to provide a compensation assist current to the steering motor depending on whether the torque value is positive or negative; And a current value determining step of determining the compensation assist current value when supply of the compensation assist current is determined.

According to the embodiments as described above, by preventing the slope of the assist current from becoming zero when the steering wheel passes the state where the torque value is zero, it is possible to prevent the notch generated due to the slope of the assist current being zero have.

1 is a graph showing a relationship between a conventional torque and an assist current.
2 is a graph showing a relationship between a conventional torque and a steering angle.
3 is a schematic block diagram of a steering control apparatus according to the present invention.
4 is a graph showing the relationship between the torque and the assist current according to the present invention.
5 is a flowchart illustrating a process of compensating an assist current in the steering control apparatus according to the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

3 is a schematic block diagram of a steering control apparatus according to the present invention.

The steering control device according to the present invention corrects the assist current provided to the steering motor based on the driver's torque, the steering direction, and the steering angle velocity, and includes the torque sensor 10, the steering angle sensor 20, the steering angle velocity sensor 30, A vehicle speed sensor 40, a steering control unit 50, a steering compensation unit 60, and a driving circuit unit 70.

The torque sensor 10 is installed in a steering column connected to a steering wheel, detects a torque of a steering column generated when the steering wheel is steered left and right, and outputs a torque value. The output torque value is transmitted to the steering control unit 50, And may be provided to the compensation unit 60. At this time, the torque value may have a positive or negative value depending on whether the steering wheel is steered counterclockwise or clockwise from the neutral position.

In the present invention, when the steering wheel is steered in the clockwise direction from the neutral position for the sake of convenience of explanation and when the steering wheel is steered again to the neutral position, the torque value becomes positive and the steering wheel is rotated counterclockwise from the neutral position, It is assumed that the torque value becomes negative.

The steering angle sensor 20 senses the steering angle indicating the degree of rotation of the steering wheel and the steering direction indicating the direction of rotation when steering the steering wheel, and provides the steering angle to the steering control unit 50 and the steering compensation unit 60. In this case, the steering direction of the steering wheel may be represented by plus or minus. In the present invention, the steering direction of the steering wheel is set to be positive in the clockwise direction for convenience of explanation, and the case where the steering direction is counter- . Accordingly, the steering angle sensed by the steering angle sensor 20 has a positive angle value when steering in the clockwise direction, and a negative angle value when steering in the counterclockwise direction.

The steering angle speed sensor 30 senses the steering speed of the steering wheel when the steering wheel is steered left and right. The steering angle speed sensor 30 outputs a positive value when rotated to one side with respect to one side of the steering wheel, and outputs a negative value when rotated to the other side. In the case where the steering angle velocity changes to within a certain range close to 0 or 0, the steering wheel is held in a state in which the steering wheel is in a neutral state and running in a straight state, or in a state in which the driver steers left and right. In this embodiment, Or within a certain range close to zero, the compensation mode is not applied.

The vehicle speed sensor 40 senses the speed of the vehicle and can provide the sensed speed of the vehicle to the steering control unit 50. [

The steering control unit 50 selects an assist current value applied to the steering motor by using an algorithm previously set and stored in a memory (not shown). At this time, the steering control unit 50 selects the assist current value for performing the steering function in consideration of the torque value and the vehicle speed. The case where the steering control value is selected and supplied to the steering motor in this way is referred to as a normal mode in the present invention.

The steering compensation unit 60 selects a compensation assist current so that a section where the slope of the assist current becomes zero when a predetermined condition is reached and has a compensation table in which the compensation assist current is set according to the torque value and the vehicle speed .

The steering compensator 60 can determine the compensation of the assist current using the torque value sensed by the torque sensor 10, the steering angle speed value sensed by the steering angle sensor 30, and the increase / decrease of the torque value.

When the torque value is supplied from the torque sensor 10, the steering compensator 60 determines whether the torque value is positive or negative, and compares the previous torque value with the current torque value at a predetermined time interval, It is possible to judge whether the steering angle is in a predetermined range including 0 or 0 and determine whether to compensate the assist current.

The case where the assist current is compensated in the steering compensator 60 is referred to as a compensation mode, and the compensation mode is executed in the following two cases.

The case where the torque value from the first torque sensor 10 is in an increase state and the torque value is negative and the case where the second torque value is in the decrease state and the torque value is plus. In both cases, the steering angle velocity should not be zero or fall within a predetermined range including zero.

In this compensation mode, the steering compensation unit 60 can determine the compensation assist current such that the slope of the assist current value changes more rapidly than the normal mode in the section where the torque value is zero. That is, the steering compensation unit 60 determines the compensation assist current so that the absolute value of the assist current value becomes larger.

For example, when the torque value is changed from -0.8 N · m to -0.5 N · m, in the normal mode controlled by the steering control unit 50, not the assist current corresponding to -0.5 N · m, An assist current corresponding to m is provided to the steering motor. However, when the compensation mode is executed by the steering compensation unit 60, an assist current corresponding to -0.3 N m is provided to the steering motor. Accordingly, the steering compensation unit 60 controls the compensation mode to be further provided as a steering motor by an assist current corresponding to 0.4 Nm in comparison with the normal mode.

On the other hand, when the torque value is changed from -0.4 N · m to -0.1 N · m, an assist current corresponding to -0.3 N · m is provided to the steering motor in the normal mode controlled by the steering control unit 50. However, when the compensation mode controlled by the steering compensation section 60 is executed, an assist current corresponding to 0.2 Nm is provided to the steering motor. Accordingly, the steering compensation unit 60 controls the compensation mode to be further provided with the steering motor by an assist current corresponding to 0.5 Nm in comparison with the normal mode.

As another example, when the torque value is changed from 0.8 N · m to 0.5 N · m, an assist current corresponding to 0.7 N · m is provided to the steering motor in the normal mode by the steering control unit 50. However, the steering compensator 60 controls the assist motor to provide an assist current corresponding to 0.3 Nm in the compensation mode. Accordingly, in the compensation mode by the steering compensator 60, the steering motor is supplied with the assist current less than the assist current corresponding to 0.4 Nm in comparison with the normal mode.

On the other hand, when the torque value is changed from 0.4 N · m to 0.1 N · m, an assist current corresponding to 0.3 N · m is provided to the steering motor in the normal mode controlled by the steering control unit 50, In the compensation mode controlled by the controller 60, an assist current corresponding to -0.2 N m is provided to the steering motor. Accordingly, the steering compensator 60 controls the compensating mode to be provided as less as the steering motor by the assist current corresponding to 0.5 N m than the normal mode.

As described above, the steering compensation unit 60 controls the assist motor so that the assist current, which is increased by a certain amount or more than the normal mode, is supplied to the steering motor. The steering compensator 60 may vary the degree of increase or decrease of the assist current according to the degree of increase or decrease of the torque value or the magnitude of the changed torque value.

That is, as in the above-mentioned example, the steering compensator 60 controls the assist current to be less than the normal mode by 0.4 Nm when the torque value is changed from 0.8 N · m to 0.5 N · m, When the value decreases from 0.4 N · m to 0.1 N · m, it can be controlled to provide less assist current than the normal mode by 0.5 N · m.

On the other hand, the steering compensation unit 60 does not apply the compensation mode when the steering angle velocity provided from the steering angle velocity sensor 30 keeps 0 for a predetermined time or fluctuates within a certain range close to zero. In the case where the steering angle speed is kept at 0 for a certain period of time or fluctuates within a range close to 0, since the driver holds the steering wheel in a state in which the vehicle runs straight or steers left and right, There is no need to apply the mode.

Like the steering control unit 50, the steering compensation unit 60 may vary the magnitude and the degree of the increase / decrease of the compensation assist current according to the speed of the vehicle provided from the vehicle speed sensor 40. [

The driving circuit unit 70 receives a control signal according to the assist current value and the compensation assist current value selected from the steering control unit 50 and the steering compensation unit 60 and controls the current supplied to the steering motor.

FIG. 4 is a graph showing the relationship between the torque and the assist current indicating the section to which the compensation mode according to the present embodiment is applied.

The upper line in the graph of FIG. 4 is a graph line generated when the torque increases, and the lower line is a graph line generated when the torque decreases.

As shown in FIG. 4, when the torque value is in the increase state, the compensation mode is performed when the torque value is negative, as indicated by a bold line in the third quadrant and the fourth quadrant of the graph. When the torque value is in the reduced state, the compensation mode is performed when the torque value is positive as indicated by a bold line in the first and second quadrants of the graph.

Here, when the torque value is in the increased state, the steering wheel is wound to the neutral position and the steering wheel is wound to the neutral position. For example, assuming that the torque value increases when winding in the clockwise direction, when the steering wheel is wound clockwise at the neutral position or when the steering wheel is released in the neutral state while being wound in the counterclockwise direction, In an increased state.

In the case of the torque value, as described above, in the present embodiment, the torque value is positive when steering the steering wheel in the clockwise direction, and the torque value is negative when steering is performed in the counterclockwise direction. That is, when the steering wheel is wound clockwise, the torque value becomes positive, and when the steering wheel is wound in the counterclockwise direction, the torque value becomes negative.

Accordingly, when the torque value is in the increased state and the torque value is negative, the steering wheel is released to the neutral position in the state where the steering wheel is wound in the counterclockwise direction. When the torque value is in the reduced state and the torque value is positive Is a case where the steering wheel is unwound to the neutral position in a state where the steering wheel is wound clockwise.

That is, when the compensation current is determined by the steering compensator 60 and the assist current value is adjusted, the steering wheel is released from the state of being wound in the counterclockwise or clockwise direction to the neutral state. In both cases, since the steering wheel is directed to the neutral position, the slope of the assist current becomes zero in the past, and the section in which the assist current becomes zero becomes long, which causes the notch fill to appear.

A process of implementing the compensation mode in the steering control apparatus having such a configuration will now be described with reference to FIG.

When the vehicle starts to operate, the torque sensor 10, the steering angle sensor 20, the steering angle velocity sensor 30, and the vehicle speed sensor 40 detect the torque, the steering angle, the steering angle velocity, The steering angle speed and the vehicle speed are provided to the steering control unit 50 and the torque and steering angle speed are provided to the steering compensation unit 60. [

Then, the steering control unit 50 selects the assist current value to be provided to the steering motor in the normal mode, and the steering compensation unit 60 determines whether or not the compensation assist current is required. If the compensation assist current is required, And provides it to the drive circuit unit 70 for controlling the steering motor.

First, the steering compensator 60 receives the steering angle velocity value from the steering angle velocity sensor 30 and determines whether the absolute value of the steering angle velocity is larger or smaller than the absolute value of the preset value (S500). In this case, a may be zero or may represent a constant angular velocity section including zero.

When the absolute value of the steering angle velocity is larger than the absolute value of a, the steering angle velocity is greater than a or smaller than -a, so that it can be determined that the steering wheel is steering. In this case, the steering compensator 60 proceeds to the next step to determine whether or not to execute the compensation mode.

On the other hand, when the absolute value of the steering angle velocity is smaller than the absolute value of a, it is determined that the steering wheel is not steering, and therefore the steering compensation unit 60 does not execute the compensation mode.

When the absolute value of the steering angle velocity is larger than the absolute value of a, the steering compensation unit 60 compares the current torque value with the previously input previous torque value to determine whether the torque value is in a state of increasing or decreasing (S510). At this time, the steering compensator 60 may first determine whether the torque value is increased or decreased according to whether the result value obtained by subtracting the previous torque value from the current torque value is greater than or less than zero. If the result is larger than 0, it means that the torque value is increasing. If the result value is smaller than 0, it means that the torque value is decreasing.

If it is determined that the torque value is increased or decreased, the steering compensator 60 determines whether the current torque value is greater than 0 in the next step, both when the result value is larger than 0 and when the result value is smaller than 0.

If the result is greater than 0, the steering compensator 60 proceeds to the normal mode if the current torque value is greater than 0, and proceeds to the compensation mode if the current torque value is less than 0 (S520). That is, the steering compensation unit 60 proceeds to the compensation mode if the torque value is in the increasing state and the current torque value is less than 0 (S540). If the torque value is in the increasing state and the current torque value is greater than 0, To proceed to the normal mode (S550).

Conversely, if the result is less than 0, the steering compensator 60 proceeds to the compensation mode if the current torque value is greater than 0, and proceeds to the normal mode if the current torque value is less than 0 (S530). That is, if the torque value is in the reduced state and the current torque value is greater than 0, the steering compensation unit 60 proceeds to the compensation mode (S540). If the torque value is in the reduced state and the current torque value is less than 0, To proceed to the normal mode (S550).

When the torque value is increasing and the current torque value is larger than 0, it corresponds to the upper graph line located in the first quadrant in the graph of FIG. 4, and the compensation mode of the steering compensator 60 is not executed in this interval Do not. Likewise, when the torque value is decreasing and the current torque value is less than 0, it corresponds to the lower graph line located in the third quadrant in the graph of FIG. 4, where the compensation mode of the steering compensator 60 is It is not executed.

In both cases, the steering wheel is steered counterclockwise or clockwise from the neutral position.

On the other hand, when the torque value increases and the torque value is smaller than 0, it corresponds to the upper graph line extending over the third quadrant and the fourth quadrant in the graph of FIG. 4. When the torque value decreases and the torque value is larger than 0 Corresponds to the lower graph line spanning the first quadrant and the second quadrant.

When the compensation mode is executed in this way, the steering compensation unit 60 selects the compensation assist current value corresponding to the vehicle speed and the current torque value from the compensation table and provides it to the drive circuit unit 70. The drive circuit unit 70 adds or subtracts the compensation assist current value from the steering compensation unit 60 to the assist current value from the steering control unit 50 and provides the assist current to the steering motor.

As described above, according to the present invention, the assist current provided to the steering motor of the steering wheel during steering is compensated according to the change of the torque value and the torque value being positive or negative. That is, by providing the compensating assist current when the steering wheel is wound in the counterclockwise or clockwise direction and then returns to the neutral position, the slope of the assist current does not become zero when the steering wheel has the torque value of zero. As a result, the notch generated due to the slope of the assist current being zero can be prevented, thereby preventing the driver from feeling a sense of heterogeneity and improving the driver's convenience.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

10: Torque sensor 20: Steering angle sensor
30: steering angle speed sensor 40: vehicle speed sensor
50: steering control unit 60: steering compensation unit
70:

Claims (17)

A torque sensor for sensing a torque generated by steering of the steering wheel; And
Determining whether the torque value is increasing or decreasing by using the torque from the torque sensor and determining whether to provide a compensation assist current to the steering motor depending on whether the torque value is positive or negative, And a steering compensation section for determining a compensation assist current value. The method according to claim 1,
Wherein the steering compensation unit is provided with a torque value at a predetermined interval from the torque sensor and subtracts the previous torque value from the current torque value to determine a change in the torque value. The method according to claim 1,
The steering compensator may include:
And determines to provide the compensating assist current when the torque value is negative, if the torque value is an increasing trend. The method according to claim 1,
The steering compensator may include:
And determines to provide the compensation assist current when the torque value is positive, if the torque value is a decreasing trend. The method according to claim 1,
Further comprising a steering angle velocity sensor for sensing a steering angle velocity of the steering wheel,
And the steering compensation unit controls to provide the compensation assist current when the steering angle velocity exceeds a predetermined range preset based on the neutral position of the steering wheel. The method according to claim 1,
Further comprising a steering angle velocity sensor for sensing a steering angle velocity of the steering wheel,
Wherein the steering compensation unit controls not to provide the compensation assist current when the steering angle velocity is zero. The method according to claim 1,
The steering compensator may include:
And determines the compensation assist current value according to the torque value. The method according to claim 1,
The steering compensator may include:
And determines the compensation assist current value according to the speed of the vehicle. Steering wheel;
A steering motor for providing a steering force to the steering wheel;
A torque sensor for sensing a torque generated by steering of the steering wheel;
A steering angle velocity sensor for sensing a steering angle velocity of the steering wheel; And
And determining whether or not the torque value is a positive or negative value and providing a compensation assist current to the steering motor in accordance with the steering angle speed, And a steering compensator for determining whether or not to provide the compensation assist current value. Sensing a torque generated by steering of the steering wheel;
Determining a change in the torque value using the torque;
A compensation determination step of determining whether to provide a compensation assist current to the steering motor depending on whether the torque value is positive or negative; And
And a current value determining step of determining the compensation assist current value when supply of the compensation assist current is determined. 11. The method of claim 10,
Wherein the increasing / decreasing step is determined by subtracting the previous torque value from the current torque value. 11. The method of claim 10,
Wherein the compensation determination step includes determining that the compensation assist current is provided when the torque value is negative when the torque value increases. 11. The method of claim 10,
Wherein the compensation determination step includes determining that the compensation assist current is provided when the torque value is positive if the torque value is a decrease trend. 11. The method of claim 10,
Further comprising sensing a steering angle velocity of the steering wheel,
Further comprising the step of controlling to provide the compensation assist current when the steering angle velocity fluctuates exceeding a predetermined range preset based on the neutral position of the steering wheel. 11. The method of claim 10,
Further comprising sensing a steering angle velocity of the steering wheel,
And when the steering angle velocity is zero, controlling to not provide the compensation assist current. 11. The method of claim 10,
Wherein the current value determining step includes determining the compensation assist current value according to the torque value. 11. The method of claim 10,
Wherein the current value determining step includes the step of determining the compensation assist current value in accordance with the speed of the vehicle.

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