KR101992338B1 - Vehicle pulling compensation apparatus for steer-by-wire system and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for compensating a vehicle torque of a steer-by-wire system, including an information receiving unit for receiving at least one of torque information, steering angle information and running information of a vehicle, the detected torque information, And a control unit for calculating an average torque value of each of the reaction motor and the steering motor and determining whether the vehicle is in the straight running state, And a torque calculating unit for calculating a compensation angle of the steering wheel corresponding to the compensation torque, and the calculated compensation torque is applied to the steering motor, and the calculated compensation angle is applied to the reaction force motor And a torque compensator for controlling the torque compensator.

Description

TECHNICAL FIELD [0001] The present invention relates to a steer-by-wire system, and more particularly,

The present invention relates to an apparatus and a method for compensating for torque of a vehicle equipped with a steer-by-wire system having left and right independent front and rear wheels.

BACKGROUND OF THE INVENTION [0002] Conventional electric power steering (EPS) is an internal power steering system (EPS) in which an internal cause of a vehicle, such as an inclination of a road surface, a wheel alignment change of a vehicle, , A compensation torque for compensating for a leaning of the vehicle in a straight running state of the vehicle when a leaning phenomenon occurs due to an external cause of the vehicle, such as a lateral wind occurring on the road. Then, the computed steering compensation torque is applied to a motor that outputs the steering assist force of the vehicle to solve the vehicle drift phenomenon.

Therefore, this vehicle lean compensation logic improves the convenience of operation when the vehicle is traveling at a high speed straight ahead.

Recently, a motor (actuator) is additionally provided instead of removing a mechanical coupling device such as a steering column, a universal joint, or a pinion shaft located between a steering wheel and a wheel so as to allow steering of the vehicle Steer By Wire (SBW) systems have been developed and applied.

In particular, the steer-by-wire system (SBW) may include a reaction motor that provides a weight to the steering force when the driver operates the steering wheel, and a steering motor that adjusts the angle of the wheel.

Since the steer-by-wire system (SBW) also causes the steering of the steering wheel to compensate for this, the control logic, which compensates for the deviation of the steering motors as well as the steering motors, .

In view of the foregoing, it is an object of the present invention to provide an apparatus and a method for compensating torque caused by a vehicle deviation phenomenon in each of a reaction force motor and a steering motor of a steer-by-wire system.

The present invention also provides an apparatus and method for compensating for vehicle deviation that gradually compensates for torque due to vehicle leaning, thereby reducing the sense of heterogeneity during steering operation.

According to an aspect of the present invention, there is provided an apparatus for compensating for vehicle deviation in a steer-by-wire system, including an information receiver for receiving at least one of torque information, steering angle information and driving information of a vehicle, A steering angle determining unit for determining whether the vehicle is in a straight running state based on the steering angle information and the running information; and a controller for calculating an average torque value of each of the reaction motor and the steering motor, A torque calculating section for calculating a compensation torque of the steering motor compensating the leaning and calculating a compensation angle of the steering wheel corresponding to the compensation torque and the calculated compensation torque to the steering motor, And a torque compensating unit for applying the torque to the reaction force motor to control the operation.

According to another aspect of the present invention, there is provided a method of compensating for vehicle steepness in a steer-by-wire system, comprising the steps of: receiving at least one of torque information, steering angle information and driving information of a vehicle; Determining whether the vehicle is in a straight running state based on the torque information, the steering angle information, and the running information; calculating an average torque value of each of the reaction motor and the steering motor, Calculating a compensation torque of the steering motor that compensates for the deviation of the vehicle, calculating a compensation angle of the steering wheel corresponding to the compensation torque, and applying the calculated compensation torque to the steering motor, And a torque compensation step of applying the compensation angle to the reaction force motor to control the operation.

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

As described above, according to the present invention, the stability of the straight running can be provided by progressively compensating the torque according to the leaning state of the vehicle.

In addition, since the steering angle of the steering wheel is compensated as well as the torque due to the vehicle leaning phenomenon is compensated, there is an effect of minimizing the heterogeneity of the driving operation in the straight running.

FIG. 1 is a block diagram of a steer-by-wire system vehicle deflection compensating apparatus according to an embodiment of the present invention.
2 is a simplified block diagram of a steer-by-wire system including a vehicle deflection compensator according to an embodiment of the present invention.
3 is a schematic view showing an example of a steer-by-wire type power assist steering apparatus according to an embodiment of the present invention.
4 is a flowchart illustrating a method of compensating a vehicle steepness of a steer-by-wire system according to an embodiment of the present invention.
5 is a flowchart illustrating a method of compensating a vehicle steepness of a steer-by-wire system according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Although the first, second, etc. are used to describe various elements, components and / or sections, it is needless to say that these elements, components and / or sections are not limited by these terms. These terms are only used to distinguish one element, element or section from another element, element or section. Therefore, it goes without saying that the first element, the first element or the first section mentioned below may be the second element, the second element or the second section within the technical spirit of the present invention.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms "comprises" and / or "made of" means that a component, step, operation, and / or element may be embodied in one or more other components, steps, operations, and / And does not exclude the presence or addition thereof.

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

FIG. 1 is a block diagram of a vehicle tilt compensation apparatus 100 of a steer-by-wire system 20 according to an embodiment of the present invention. FIG. 2 is a block diagram of a vehicle tilt compensation apparatus 100 according to an embodiment of the present invention. Wire system 20 according to the first embodiment of the present invention.

Referring to FIG. 1, an apparatus 100 for compensating a torque of a vehicle according to an embodiment of the present invention includes an information receiving unit 110 for receiving at least one of torque information, steering angle information and running information of a vehicle, A steering angle determination unit 120 for determining whether the vehicle is in a straight running state based on the steering angle information and the running information, and a controller 120 for calculating an average torque value of each of the reaction motor and the steering motor, A torque calculating unit (130) for calculating a compensation torque of the steering motor to compensate for the deviation of the vehicle, calculating a compensation angle of the steering wheel corresponding to the compensation torque, and a control unit And a torque compensator 140 for applying the calculated compensation angle to the reaction force motor to control the operation.

2, the running information may be information detected from at least one sensor among a vehicle speed (wheel speed) sensor 25, a lateral acceleration sensor 27, and a yaw rate sensor 26 provided in the vehicle. have. At this time, the speed of the wheel sensed by the vehicle speed sensor 25 may include the speeds of the right and left front wheels and the speeds of the right and left rear wheels.

The steering angle information may be information sensed from the steering angle sensor 21 of each of the reaction motor 22 and the steering motor 24. The torque information may be information on the torque of each of the reaction motor 22 and the steering motor 24. [ But it is not limited thereto.

In other words, the steer-by-wire system proposed in the present invention does not necessarily include a steering angle sensor and a torque sensor as a system for controlling left and right independent front and rear wheels, so that the steering angle information and the torque information are transmitted to a motor position sensor It may be the information detected by the sensor.

Therefore, the information receiving unit 110 can receive information from various sensors and travel support systems that measure the traveling state of the vehicle, in addition to the sensors described above.

The travel determiner 120 determines the steering torque value, the steering angle range, the steering angle speed range, the yaw angle range, the lateral acceleration range, the wheel speed range, and the like for a predetermined time based on the information received from the information receiving unit 110 It can be determined whether the vehicle is running straight ahead.

For example, when the wheel speed received from the vehicle speed sensor 25 of the vehicle is out of the predetermined speed range and the amount of change of the steering torque value and the steering angle speed are equal to or less than a predetermined value, .

On the other hand, when the wheel speed is within the predetermined speed range, or when the amount of change in the steering torque value and the steering angle speed are equal to or greater than a predetermined value, the driving determination unit 120 does not activate the function of the vehicle- The steering control that is being performed can be continuously performed.

The torque calculating unit 130 receives the steering angle information and the torque information from the steering angle sensor 21 and the torque sensor 23 of the reaction motor 22 and the steering motor 24 and calculates the average torque value If the average torque value is equal to or greater than the threshold value, the compensation torque can be calculated. At this time, the threshold value may be set differently from the reaction force motor 22 and the steering motor 24.

The torque calculating unit 130 may determine the first or second skid state based on the average torque value. At this time, the second leaning state is a leaning state in which a compensation torque greater than the first leaning state is calculated.

That is, the second leaning state takes a longer time to gradually compensate the torque than the first leaning state, and the reference value for determining the second leaning state and the first leaning state is the average lean state, May be a difference value between the current torque values changed by the current steering operation of the driver.

The torque compensating unit 140 may apply the compensating torque to the steering motor 24 at a constant torque per unit time in accordance with the calculation result from the torque calculating unit 130 or may apply the compensating torque and the compensating angle to the low- (Low Pass Filtering) and applied to the steering motor 24 and the reaction force motor 22, respectively.

In this case, the low-pass filter passes only a low-frequency current having a frequency equal to or lower than a threshold frequency, and applies a first-order low-pass filter or a second-order low-pass filter to gradually apply the compensation torque and the compensation angle.

In addition, the torque compensating unit 140 can generate a reference compensating torque model or a reference compensating angular model according to various vehicle types and the type of the steer-by-wire system 20. [ Therefore, when a leaning phenomenon occurs in the vehicle, the compensation torque is directly applied to the steering motor 24 and the reaction force motor 22 based on the model, thereby improving the calculation processing speed of the vehicle deviation compensation device 100 have.

The torque compensating unit 140 may select at least one steering motor 24 among the left front wheel, the right front wheel, the right rear wheel, and the left rear wheel according to the degree of leaning of the vehicle and the driving environment to apply the compensation torque.

2, an ECU (electronic control unit) of a reaction force motor 22 of a typical steer-by-wire system 20 receives steering angle information from the steering angle sensor 21 by steering of the driver's steering wheel And calculates the steering ratio of the wheel based on the wheel speed information sensed by the vehicle speed sensor 25, thereby calculating the target steering angle of the wheel.

Then, the ECU of the steering motor 24 can receive the target steering angle calculated by the reaction force motor 22 and control the steering of the vehicle's wheels. At this time, the ECU of the steering motor 24 receives the torque information and the steering angle information from the torque sensor 23 or the motor position sensor, estimates a rack-force, which is a force applied to the rack bar, Can be transmitted.

The steering ratio is a ratio between the steering angle of the steering wheel and the rotational angle of the front wheel or the rear wheel of the vehicle and may vary depending on the type of the vehicle. ) Can be stored at design time.

Then, the ECU of the reaction force motor 22 can provide a stable steering feeling to the driver by controlling the rotation angle of the steering wheel by converting the rack-force.

The steering angle sensor 21, the torque sensor 23, the vehicle speed sensor 25, the yaw rate sensor 26, and the lateral acceleration sensor (not shown) 27, and the like, and can determine whether the vehicle is in the straight running state.

At the same time, the vehicle tilt compensation device 100 receives the steering angle information and the torque information from the steering angle sensor 21 and the torque sensor 23 of the reaction motor 22 and the steering motor 24, respectively, By calculating the average torque value, it is possible to determine the degree of the vehicle leaning state and to calculate the compensation torque based on this.

The vehicle tilt compensation device 100 estimates the compensation angle based on the compensation torque, and applies the control algorithm such as a low-pass filter or the like to gradually increase the compensation torque and the compensation angle to the reaction force motor 22 and the steering motor (24).

Then, the ECU of the reaction force motor 22 adds the compensation torque to the target steering angle, and the ECU of the steering motor 24 adds the compensation angle to the rotation angle of the steering wheel according to the target steering angle, Output the final steering assist force to the botters.

That is, the vehicle deflection compensating apparatus 100 according to the present invention compensates for the steering effort not only to the steering motor 24 of the steer-by-wire system 20 but also to the reaction force motor 22, I suggest.

3 is a schematic view showing an example of a steer-by-wire type power assist steering apparatus according to an embodiment of the present invention.

As shown in the figure, the steer-by-wire type power assist steering apparatus 300 (hereinafter, referred to as a steer-by-wire apparatus) includes a steering wheel 301 directly operated by a driver for steering, A steering motor 306 connected to the gear box 303 through a tie rod 304 to provide a steering torque to the wheels, a steering angle sensor, a torque sensor An electronic control unit 307 (ECU) and an SBW control module 308, a gear box 303, a tie rod 304, and wheels (front wheels or front wheels) for controlling each motor based on electric signals received from sensor modules such as sensors, Rear wheels 305).

Here, the steering wheel 301 is generally called a vehicle handle. When the driver rotates the steering wheel 301, the driver rotates the steering wheel 301 to change the direction of the automobile. When the driver rotates the steering wheel 301, The torque sensor and the steering angle sensor sense the rotational force, the rotational angle and the rotational angular velocity, sense the steering operation of the driver, and transmit the sensed signal to the electronic control unit 307 (ECU).

Here, the electronic control unit 307 (ECU) controls the outputs of the reaction force motor 302 and the steering motor 306 on the basis of not only the torque sensor and the steering angle sensor but also various sensor information provided in the vehicle.

The steering motor 306 is a device for compensating the steering operation of the driver. By transmitting the output of the steering motor 306, that is, the steering force to the wheel 305 via the tie rod 304, The direction of the wheel 305 is manipulated as much as the wheel 305 is rotated.

Since the reaction force motor 302 and the steering motor 306 are connected to the output terminal of the SBW control module 308 respectively, the control logic is selectively driven by a control signal applied from the SBW control module 308 in which the control logic is programmed . In addition, the SBW control module 308 can implement a fail-safe function.

However, the steer-by-wire device 300 is a system for controlling left and right independent front wheels and rear wheels. Since the steering wheel 301 is not an indispensable element, it can be removed and there is no need to install a torque sensor and a steering angle sensor. Steering angle information can be obtained from the motor position sensor and the motor torque sensor.

Therefore, the steer-by-wire apparatus 300 is an apparatus optimized for autonomous driving, simplifying parts and reducing the weight of the vehicle body, and steering of the vehicle can be performed with a simple operation input.

4 is a flowchart illustrating a method of compensating a vehicle steepness of a steer-by-wire system according to an embodiment of the present invention.

The method of compensating for vehicle deviation according to an embodiment of the present invention includes an information receiving step (S400) of receiving at least one of torque information, steering angle information and running information of a vehicle, the detected torque information, the steering angle information, (S410) for determining whether the vehicle is in the straight running state based on the steering angle of the vehicle, calculating an average torque value of each of the reaction motor and the steering motor if it is determined that the vehicle is in the straight running state, (S420) for calculating a compensation angle of the steering wheel corresponding to the compensation torque, calculating the compensation torque of the motor, applying the calculated compensation torque to the steering motor, and outputting the calculated compensation angle to the reaction force And a torque compensating step (S430) for applying the torque to the motor to control the operation.

More specifically, the driving determination step S410 determines the steering torque value, the steering angle range, the steering angle speed range, the yaw angle range, the lateral acceleration range, the wheel speed range, and the like for a predetermined time based on the information received in the information reception step S400 It is possible to determine whether the vehicle is running straight ahead.

The torque calculation step S420 receives the steering angle information and the torque information from the steering angle sensor and the torque sensor of each of the reaction motor and the steering motor and calculates the average torque value for a predetermined time period. And the compensating torque can be calculated if it is not less than the threshold value.

The torque calculating step S420 may determine the first or second lean state based on the average torque value. At this time, the second leaning state is a leaning state in which a compensation torque greater than the first leaning state is calculated.

The torque compensation step S430 may apply the compensation torque to the steering motor at a constant torque per unit time in accordance with the result calculated from the torque calculation step S420 or may apply the compensation torque and the compensation angle to the low- (Low Pass Filtering), and can be applied to the steering motor and the reaction force motor, respectively.

5 is a flowchart illustrating a method of compensating a vehicle steepness of a steer-by-wire system according to an embodiment of the present invention.

In the information reception step S400, at least one of the torque information, the steering angle information, and the travel information of the vehicle is received (S500).

In step S410, a steering torque value, a steering angle range, a steering angle speed range, a yaw angle range, a lateral acceleration range, a wheel speed range, and the like for a predetermined time are calculated based on the received information (S510).

And determines whether the vehicle is running straight on the basis of the calculated information (S520). For example, when the wheel speed is outside the predetermined speed range and the amount of change in the steering torque value and the steering angle speed are equal to or less than a predetermined value, it can be determined that the vehicle is running straight.

If the vehicle is not in the straight running state, the steering control is continuously performed without activating the step of compensating the vehicle leaning method, and at least one of torque information, steering angle information, and driving information is again transmitted in the information receiving step (S400) The above is re-received (S500).

On the other hand, if the vehicle is in the straight running state, the steering angle information and the torque information are received from the steering angle sensor and the torque sensor provided in the reaction motor and the steering motor, respectively, and the average torque value (S530).

Then, the torque present value changed by the driver's steering operation is checked (S540), and a difference value between the average torque value and the torque current value is estimated.

Then, it is determined whether the leaning state of the vehicle is the first leaning state or the second leaning state based on the average torque value and the estimated difference value (S550). At this time, the second leaning state is a leaning state in which a compensation torque greater than the first leaning state is calculated.

(Step S560). If the torque average value of the steering motor to which the compensation torque is applied and the torque average value of the reaction force motor are equal to or less than the predetermined value, (S530).

On the other hand, if the leaning state of the vehicle is the second leaning state, a compensation torque for the second leaning state is calculated (S570), and a compensation angle corresponding to the compensation torque is calculated (S580).

In the torque compensation step S430, the compensation torque is applied to the steering motor, and the compensation angle is applied to the reaction force motor (S590) to compensate the torque due to the leaning of the vehicle. At this time, according to the calculated result, the compensation torque is applied to the steering motor at a constant torque per unit time, or the compensation torque and the compensation angle are applied to a low-pass filter, .

As described above, since the torque according to the leaning state of the vehicle is compensated, it is possible to provide the stability of the straight running, and not only the torque due to the leaning of the vehicle is gradually compensated, but also the steering angle to the steering wheel is compensated. There is an effect of minimizing heterogeneity.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: deflection device
110: information receiving unit 120:
130: torque calculating unit 140: torque compensating unit
20: Steer-by-wire system
21: steering angle sensor 22: reaction force motor
23: torque sensor 24: steering motor
25: vehicle speed sensor 26: yaw rate sensor
27: lateral acceleration sensor

Claims (11)

An information receiving unit for receiving torque information, steering angle information and running information of the vehicle;
A traveling determining unit determining whether the vehicle is in a straight running state based on the detected torque information, the steering angle information, and the running information;
Calculates the average torque value of each of the reaction motor and the steering motor, calculates a compensation torque of the steering motor to compensate for the deviation of the vehicle, and calculates a compensation amount of the steering wheel corresponding to the compensation torque A torque calculation unit for calculating an angle; And
A torque compensator that applies the calculated compensation torque to the steering motor and applies the calculated compensation angle to the reaction force motor to control the operation; And a steering angle sensor for detecting steering angle of the steering wheel. The method according to claim 1,
Wherein the travel information is information sensed by at least one of a vehicle speed sensor, a lateral acceleration sensor, and a yaw rate sensor. The method according to claim 1,
The torque calculating section calculates,
And calculates the compensation torque when the average torque value over a predetermined time is equal to or greater than a threshold value. The method according to claim 1,
The torque calculating section calculates,
And determines a first leaning state and a second leaning state based on the average torque value. 5. The method of claim 4,
Wherein the second leaning state is a state in which a compensation torque greater than the first leaning state is calculated. The method according to claim 1,
Wherein the torque compensating section comprises:
Wherein the compensation torque is applied to the steering motor at a constant torque per unit time. The method according to claim 1,
Wherein the torque compensating section comprises:
Wherein the compensation torque and the compensation angle are applied to a low-pass filter and applied to the steering motor and the reaction force motor, respectively. An information receiving step of receiving torque information, steering angle information and running information of the vehicle;
Determining whether the vehicle is in a straight running state based on the detected torque information, the steering angle information, and the running information;
Calculates the average torque value of each of the reaction motor and the steering motor, calculates a compensation torque of the steering motor to compensate for the deviation of the vehicle, and calculates a compensation amount of the steering wheel corresponding to the compensation torque A torque calculating step of calculating an angle; And
A torque compensation step of applying the calculated compensation torque to the steering motor and applying the calculated compensation angle to the reaction force motor to control the operation; And a steering angle sensor for detecting steering angle of the steering wheel. 9. The method of claim 8,
The torque calculating step includes:
Wherein the compensating torque is calculated when the average torque value for a predetermined time is equal to or greater than a threshold value. 9. The method of claim 8,
The torque compensation step includes:
Wherein the compensation torque is applied to the steering motor at a constant torque per unit time. 9. The method of claim 8,
The torque compensation step includes:
Wherein the compensating torque and the compensation angle are applied to a low-pass filter and applied to the steering motor and the reaction force motor, respectively.

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