KR102016936B1 - Apparatus and Method for Controlling Steering of Vehicle According to Thread with Road Surface - Google Patents

Abstract

The present invention relates to an apparatus and a method for controlling steering of a vehicle according to a thread with a road surface, wherein the apparatus for controlling steering of a vehicle according to a thread with a road surface comprises: an information collection unit collecting at least one of vehicle steering information, a front wheel speed, and a rear wheel speed; a wheel speed calculation unit calculating an average wheel speed of the front and rear wheels for a predetermined time based on collected wheel speeds; a ground determination unit determining a ground state between a road surface and a front wheel and a ground state between the road surface of a rear wheel based on the calculated average wheel speed; and a signal output unit outputting a control signal of a restoring current with respect to steering torque in accordance with a determined result.

Description

Steering control device and control method according to ground state with road surface {Apparatus and Method for Controlling Steering of Vehicle According to Thread with Road Surface}

The present invention relates to a steering control device and a control method according to the road grounding state, and more particularly to an apparatus and method for determining the ground state between the front and rear wheels and the road surface of the vehicle and to control the output of the restored current to the steering torque. It is about.

In general, when the uphill and downhill roads are alternately present, the ground between the front wheel or the rear wheel of the vehicle and the road surface is temporarily reduced when the two-wheel drive vehicle travels at a high speed, and bouncing or pitching may occur in the vehicle. Can be. That is, when bouncing or pitching occurs, the load on the front or rear wheels of the vehicle is momentarily reduced.

In particular, if the uphill and downhill roads are curved roads, steering is performed when the front or rear wheels of the vehicle are not grounded with the road surface. In this case, when the front or rear wheels are grounded again on the road surface due to an incorrect steering assistance It can be oversteer or understeer, increasing the likelihood of a dangerous situation occurring.

Therefore, the control device and method of the steering system for solving the above problems is urgent situation.

The present invention is to solve the above problems, and provides an apparatus and method for controlling the steering based on the ground state between the front and rear wheels and the road surface of the vehicle.

In addition, the present invention provides an apparatus and method for controlling the output of the restored current to the steering in accordance with the ground state between the vehicle and the road surface.

Problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

Steering control apparatus according to an embodiment of the present invention for achieving the above object, an information collection unit for collecting at least one or more of the steering information of the vehicle, the wheel speed (wheel speed) of the front wheel and the rear wheel, collected A wheel speed calculator configured to calculate an average wheel speed of the front wheel and an average wheel speed of the rear wheel for a predetermined time based on a wheel speed, a ground state between the road surface and the front wheel based on the calculated average wheel speed, and the road surface and the It may include a ground determination unit for determining a ground state between the rear wheels and a signal output unit for outputting a control signal of the restoration current for the steering torque in accordance with the determined result.

And the steering control method according to an embodiment of the present invention for achieving the above object, information collection step of collecting at least one or more of the steering information of the vehicle, the wheel speed (wheel speed) of the front wheel and the wheel speed of the rear wheel, collecting A wheel speed calculation step of calculating an average wheel speed of the front wheel and an average wheel speed of the rear wheel for a predetermined time based on the determined wheel speed, a ground state between the road surface and the front wheel and the road surface based on the calculated average wheel speed And a ground determination step of determining a ground state between the rear wheel and the rear wheel, and a signal output step of outputting a control signal of a restoration current for steering torque according to the determined result.

Other specific details of the invention are included in the detailed description and drawings.

As described above, according to the present invention, it is possible to minimize the risk of an accident when driving on a road having a slope and curvature.

In addition, by simply implementing the control logic of the restoration current for the steering, it is possible to control the steering at a high speed.

1 is a view schematically illustrating an electric power steering system including a steering control device according to an embodiment of the present invention.
2 is a block diagram illustrating a steering control device according to an embodiment of the present invention.
3 is a flowchart illustrating a steering control method according to an embodiment of the present invention.
4 is a detailed flowchart illustrating a steering control method according to an embodiment of the present invention.
5 is an example of the first flag and the second flag signal output of the steering control method according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Although the first, second, etc. are used to describe various elements, components and / or sections, these elements, components and / or sections are of course not limited by these terms. These terms are only used to distinguish one element, component or section from another element, component or section. Therefore, the first device, the first component, or the first section mentioned below may be a second device, a second component, or a second section within the technical spirit of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and / or “made of” refers to a component, step, operation, and / or element that includes one or more other components, steps, operations, and / or elements. It does not exclude existence or addition.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a view schematically illustrating an electric power steering system 100 including a steering control device 120 according to an embodiment of the present invention.

Referring to FIG. 1, the electric steering system 100 includes a steering assistance motor 110 that provides a steering assistance force according to a steering wheel operation of a vehicle, and a current assist control map for steering assistance force according to a vehicle speed is stored to assist steering. Control unit (ECU) 130 for detecting an abnormality of the motor 110 or controlling the driving, a wheel speed sensor 140 for detecting wheel speeds of the front left and right wheels and the left and right rear wheels of the vehicle, and detects a steering angle that is a degree of rotation of the steering wheel. The steering angle sensor 150, a torque sensor 160 for detecting a steering torque which is a rotational force of the steering shaft connected to the steering wheel may include a steering control device 120 according to the present invention.

In detail, information detected by at least one or more of the wheel speed sensor 140, the steering angle sensor 150, and the torque sensor 160 is transmitted to the steering control device 120 and the control unit ECU, and the steering control device. The controller 120 and the ECU 130 calculate a restoring current or assist current for the steering torque based on the sensed information, and output the steering current to the steering assist motor 110. The steering assistance motor 110 may then control steering of the vehicle by outputting steering assistance force according to the restoration current or assist current.

However, FIG. 1 is merely an example of briefly describing the electric steering system 100, and the present disclosure is not limited to the system to which the steering control apparatus 120 of the present invention is applied.

2 is a block diagram illustrating a steering control device 120 according to an embodiment of the present invention.

Referring to FIG. 2, the steering control apparatus 120 according to the present invention includes an information collection unit 210 for collecting at least one or more of steering information of a vehicle, wheel speed of a front wheel, and wheel speed of a rear wheel, A wheel speed calculator 220 that calculates an average wheel speed of the front wheel and an average wheel speed of the rear wheel for a predetermined time based on the collected wheel speed, and a ground state between the road surface and the front wheel based on the calculated average wheel speed. And a ground determination unit 230 for determining a ground state between the road surface and the rear wheel and a signal output unit 240 for outputting a control signal of a restoration current for steering torque according to the determined result.

In detail, the information collecting unit 210 may collect the steering information from the steering angle sensor 150 or the torque sensor 160, and the wheel speeds of the front left and right wheels and the rear wheel left and right wheels from the wheel speed sensor 140. Can collect speed. In this case, the vehicle may be a two-wheel drive vehicle that drives the front wheel left and right or the rear wheel left and right.

In addition to the above-described sensor device, the steering information and the wheel speed may be collected from various driving assistance systems provided in the vehicle.

Therefore, the information collection unit 210 collects information such as wireless LAN (WLAN), Wi-Fi, WiBro, WiMAX, WiMAX, WiSD, HSDPA. (High Speed Downlink Packet Access) may include a communication function, such as Bluetooth, Bluetooth (Radio Frequency Identification), infrared communication (IrDA, infrared data association), UWB (Ultra Wideband), ZigBee, CAN communication (Controller Area Network) may be included.

The wheel speed calculator 220 may calculate a difference value between the average wheel speed size of the front wheel and the average wheel speed size of the rear wheel based on the information collected from the information collector 210.

At this time, when the vehicle is a two-wheel drive vehicle, the power of the engine is transmitted to the front wheel or the rear wheel. Therefore, when the vehicle is a front wheel drive vehicle, if the traction force between the vehicle and the road surface is lost due to the occurrence of pitching or bouncing phenomenon, the wheel speed of the front wheel which transmits the driving force to the vehicle is increased, but the wheel speed of the rear wheel is constant Therefore, the wheel speed of the rear wheel can be set to the current vehicle speed.

On the other hand, when the vehicle is a rear wheel drive vehicle, the wheel speed of the rear wheel increases, but the wheel speed of the current is constant, so that the wheel speed of the front wheel can be set to the current vehicle speed.

The wheel speed calculating unit 220 may calculate wheel speeds of the front wheels and the rear wheels for a predetermined time, wherein the predetermined time is a time capable of sufficiently determining the ground state of the vehicle, and the vehicle type and driving type of the vehicle. (Front wheel drive or rear wheel drive).

Accordingly, the wheel speed calculator 220 may calculate average wheel speeds of the front wheels and the rear wheels, and calculate a difference between the magnitude of the average wheel speed of the front wheel and the magnitude of the rear wheel average wheel speed.

In addition, the ground determination unit 230 may determine whether the difference value calculated by the wheel speed calculation unit 220 is greater than or equal to a predetermined threshold speed value. In this case, the threshold speed value may mean a minimum difference value among difference values of the average wheel speed generated when the vehicle loses the grip with the road surface.

In addition, the critical speed value has a value greater than a difference value of wheel speed due to a slip phenomenon of the vehicle that occurs when the road surface is an ice road or a rain road.

In addition, when the difference value maintains the threshold speed value for a certain time, it can be determined that the grip power is lost. This is because the collected wheel speed may have an instantaneous error value regardless of the loss of traction.

In this case, the predetermined time may be preset through a vehicle test. For example, when the predetermined time is set to 50 ms, if the difference value, which is calculated every 5 ms, is maintained for 10 times, the vehicle is connected to the road surface. It can be determined that the grip power is lost.

Therefore, when the difference value is greater than the threshold speed value, the ground determination unit 230 determines that the ground state between the road surface and the front wheel or the ground state between the road surface and the rear wheel is abnormal and generates a first flag. can do. In this case, the road surface is an abnormal state, that is, a state in which the traction between the vehicle and the road surface is lost.

On the other hand, if the difference value is less than the threshold speed value, the ground determination unit 230 determines that the ground state between the road surface and the front wheel and the ground state between the road surface and the rear wheel are normal and generate a second flag. have.

In this case, the first flag may be a control signal for outputting a restoration current value as 0, and the second flag may be a control signal for outputting the restoration current value according to an increase rate having a predetermined predetermined slope.

In this case, the constant slope may be preset to a value for minimizing steering heterogeneity through a vehicle test.

The ground determination unit 230 may calculate the restoration current for steering according to the driver's manipulation based on the steering information. That is, the ground determination unit 230 receives the current steering state and the current assist map of the vehicle from the steering information and the control unit ECU 130, and applies the steering assistance force appropriate for the vehicle through the steering assistance motor 110. The restoration current value can be calculated to provide.

The signal output unit 240 may output the control signal according to the first flag or the second flag generated by the ground determination unit 230 to the steering assist motor.

That is, when the first flag is generated, since the restoration current value is 0, the driving of the steering assist motor 110 may be limited, thereby minimizing the occurrence of oversteer or understeer due to the ground force loss steering operation.

On the other hand, if the second flag is generated, since the restoration current value is increased by a predetermined slope, the steering assistance motor 110 gradually outputs the steering assistance force, thereby minimizing the heterogeneity of steering during the steering operation. .

In addition, the signal output unit 240 may output a warning signal for steering control when it is determined that the ground state between the road surface and the front wheel or the ground state between the road surface and the rear wheel is abnormal.

In this case, the warning signal may be output through at least one of an audible, visual and tactile output scheme.

Here, the auditory output method may be a voice or a warning sound, and the visual output method may be output as an image through a dashboard, a navigation, a display, a head-up display, etc. provided in the vehicle, and the tactile output method May be output by vibration or the like.

3 is a flowchart illustrating a steering control method according to an embodiment of the present invention.

Referring to FIG. 3, the steering control method according to the present invention includes an information collecting step (S300) of collecting at least one or more of steering information of a vehicle, wheel speed of a front wheel, and wheel speed of a rear wheel, and collected wheel speed. The wheel speed calculation step (S310) for calculating the average wheel speed of the front wheel and the average wheel speed of the rear wheel for a predetermined time based on the, the ground state and the road surface between the road surface and the front wheel based on the calculated average wheel speed And a ground determination step (S320) of determining a ground state between the rear wheel and the rear wheel, and a signal output step (S330) of outputting a control signal of a restoration current for steering torque according to the determined result.

4 is a detailed flowchart illustrating a steering control method according to an embodiment of the present invention.

Referring to FIG. 4, the steering information is collected from a steering angle sensor or a torque sensor, and the wheel speeds of the left and right wheels and the wheel speeds of the rear wheels are collected from a wheel speed sensor (S400).

The restored current for steering according to the driver's operation is calculated based on the steering information (S410). That is, the current steering state and the current assist map of the vehicle are received, and the restoration current value is calculated to provide a steering assistance force appropriate to the vehicle through the steering assistance motor.

In operation S420, the average wheel speed of the front wheel and the average wheel speed of the rear wheel are calculated based on the collected wheel speed.

At the same time, the difference between the magnitude of the average wheel speed of the front wheel and the magnitude of the average wheel speed of the rear wheel is calculated (S430).

Then, it is determined whether the difference is greater than or equal to the threshold speed value (S440). In this case, the threshold speed value may mean a minimum difference value among difference values of the average wheel speed generated when the vehicle loses the grip with the road surface.

If the difference is greater than or equal to the threshold speed value, it is determined that the ground state between the road surface and the front wheel or the ground state between the road surface and the rear wheel is abnormal (S450) and a first flag is generated (S460). ).

On the other hand, if the difference value is less than the threshold speed value, it is determined that the ground state between the road surface and the front wheel and the ground state between the road surface and the rear wheel are normal (S470) and generate a second flag (S480).

Then, the generated control signal according to the first flag or the second flag is output to the steering assistance motor (S490).

In this case, the first flag generates the control signal to limit the driving of the steering auxiliary motor since the restoration current value is 0, and the second flag increases the restoration current value by a predetermined slope, so that the steering assistance force in the steering assistance motor is increased. Produce a control signal to output gradually.

As described above, the steering control method according to the present invention provides a method for quickly controlling the output of the restoration current for steering in accordance with the ground state between the vehicle and the road surface.

5 is an example of the first flag and the second flag signal output of the steering control method according to an embodiment of the present invention.

FIG. 5A illustrates a restoration current output graph according to the first flag, and FIG. 5B illustrates a restoration current output graph according to the second flag.

Referring to (a) and (b) of FIG. 5, the first flag is a control signal for outputting a restoration current value as 0, and the second flag is in accordance with an increase rate having a predetermined predetermined slope. The control signal may be output, and the predetermined slope may be preset to a value that minimizes a steering heterogeneity through a vehicle test.

Specifically, since the flag value of the first flag is set to 1 and the flag value of the second flag is set to 0, the flag value is applied to logic for generating a control signal, thereby enabling fast arithmetic processing. Therefore, quick steering control is possible depending on the momentary loss of grip between the vehicle and the road surface.

When the first flag, that is, the flag value is 1, the restoration current value is 0, thereby limiting the driving of the steering assist motor, thereby minimizing the occurrence of oversteer or understeer due to the grounding force steering operation.

On the other hand, if the second flag, that is, the flag value is 0, the restoration current value is increased by a predetermined slope, thereby gradually outputting the steering assistance force from the steering assistance motor, thereby minimizing the heterogeneity of steering during the steering operation. .

As described above, according to the steering control apparatus and the control method according to the present invention, it is possible to minimize the risk of an accident when driving on a road having a slope and curvature.

In addition, by simply implementing the control logic of the restoration current for the steering, it is possible to control the steering at a high speed.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

100: electric power steering system
110: steering auxiliary motor
120: steering control device
210: information collecting unit 220: wheel computing unit
230: ground determination unit 240: signal output unit
130: control unit (ECU) 140: wheel speed sensor
150: steering angle sensor 160: torque sensor

Claims (10)

An information collector configured to collect steering information of the vehicle, wheel speed of the front wheel, and wheel speed of the rear wheel;
A wheel speed calculator configured to calculate an average wheel speed of the front wheel and an average wheel speed of the rear wheel for a predetermined time based on the collected wheel speed;
A ground determination unit determining a ground state between the road surface and the front wheel and a ground state between the road surface and the rear wheel based on the calculated average wheel speed; And
And a signal output unit configured to output a control signal of the restoration current with respect to the steering torque according to the determined result. The method of claim 1,
The wheel computing unit,
A steering control device for calculating a difference value between the average wheel speed size of the front wheel and the average wheel speed size of the rear wheel. The method of claim 2,
The ground determination unit,
And a steering control device for determining whether the difference is greater than or equal to a predetermined threshold speed value. The method of claim 3, wherein
The ground determination unit,
And the difference value is greater than or equal to the threshold speed value, and determines that the ground state between the road surface and the front wheel or the ground state between the road surface and the rear wheel is abnormal and generates a first flag. The method of claim 4, wherein
The ground determination unit,
And when the difference is less than the threshold speed value, determining that the ground state between the road surface and the front wheel and the ground state between the road surface and the rear wheel are normal and generating a second flag. The method of claim 1,
The ground determination unit,
The steering control device for calculating the restored current for the steering according to the driver's operation based on the steering information. The method of claim 5,
The first flag is a control signal for outputting a restoration current value as 0.
And the second flag is a control signal for outputting the restored current value according to an increase rate having a predetermined predetermined slope. The method of claim 7, wherein
The signal output unit,
A steering control device for outputting the control signal according to the first flag or the second flag to a steering assist motor. The method of claim 1,
The signal output unit,
And a warning signal for steering control is output when the ground state between the road surface and the front wheel or the ground state between the road surface and the rear wheel is determined to be abnormal. An information collecting step of collecting steering information of the vehicle, wheel speed of the front wheel, and wheel speed of the rear wheel;
A wheel speed calculation step of calculating an average wheel speed of the front wheel and an average wheel speed of the rear wheel for a predetermined time based on the collected wheel speed;
A ground determination step of determining a ground state between the road surface and the front wheel and a ground state between the road surface and the rear wheel based on the calculated average wheel speed; And
And a signal outputting step of outputting a control signal of the restoration current with respect to the steering torque according to the determined result.

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