KR102005943B1 - Apparatus for controlling vehicle and control method thereof - Google Patents

Abstract

A vehicle control apparatus and method are disclosed. A vehicle control apparatus according to an embodiment of the present invention includes a first wheel speed sensor for detecting a speed of a first drive wheel, a second wheel speed sensor for detecting a speed of the second drive wheel, And an electronic control unit for controlling the braking force and the driving force of the vehicle when the hopping occurs, wherein the electronic control unit judges the road surface on which the first drive wheel and the second drive wheel are located, Increase or decrease the target wheel spin on the basis.

Description

[0001] APPARATUS FOR CONTROLLING VEHICLE AND CONTROL METHOD THEREOF [0002]

The present invention relates to a vehicle control apparatus and method, and more particularly, to a vehicle control apparatus and method for controlling a vehicle in response to a hopping of a vehicle.

Generally, a traction control system of a vehicle performs traction control when an excessive driving slip occurs in a driving wheel due to a large driving force transmitted to a driving wheel of the vehicle, compared with a friction force of a road surface, And automatically adjusts the magnitude of the driving force transmitted to the driving wheels so that the maximum driving slip is maintained.

Such a traction control system operates when the magnitude of the driving slip caused by the driver's accelerator pedal operation exceeds a predetermined value. Often, the oscillation of the driving wheel speed is not attenuated and is amplified to cause a hopping phenomenon which causes shaking of the vehicle body continuously.

This hopping phenomenon is caused by the interaction of the driving system, the suspension, the tire, and the road surface. When hopping occurs, the time it takes for the tremor to naturally sink is considerably long, which can seriously disturb the driver.

Korean Patent Laid-Open Publication No. 2013-0048483 (published on May 10, 2013)

An embodiment of the present invention seeks to provide a vehicle control apparatus and method that can more quickly solve a hopping phenomenon generated during traction control.

According to an aspect of the present invention, there is provided a vehicle including: a first wheel speed sensor for detecting a speed of a first driving wheel; A second wheel speed sensor for detecting the speed of the second driving wheel; And an electronic control unit for determining whether a hopping occurs during traction control and controlling the braking force and the driving force of the vehicle when the hopping occurs, wherein the electronic control unit controls the first driving wheel and the second driving wheel And the target wheel spin can be increased or decreased based on the determined road surface.

Further, the electronic control unit may increase the target wheel spin if the determined road surface is a split road surface.

Also, the electronic control unit may reduce the proportional gain (P gain) and increase the integral gain (I gain) when following the current spin to the increased target wheel spin using the proportional integral control.

Further, the electronic control unit may reduce the target wheel spin if the determined road surface is a homonymous surface.

Also, the electronic control unit may maintain the reduction of the target wheel spin during the hopping maintenance interval from the time when the generated hopping is resolved until a predetermined time elapses.

The electronic control unit may further include a proportional gain (P gain) and an integral gain (I gain) when the spin error is a positive value when the current spin is followed by the reduced target wheel spin using the proportional integral control during the hopping maintenance period. (P / I gain), which is obtained by vectorizing the phase difference (P / I gain), and decreasing the proportional / integral gain (P / I gain) if the spin error is a negative value.

It is also preferable that the period of the wheel speed detected by the first wheel speed sensor or the second wheel speed sensor reaches the natural frequency region of the suspension of the vehicle and the amplitude of the detected wheel speed is equal to or greater than a predetermined amplitude value , And if the detected wheel speed reaches a predetermined speed value corresponding to the vehicle speed, it can be determined that the hopping has occurred.

According to another aspect of the present invention, there is provided a control method for controlling a braking force and a driving force of a vehicle when the hopping occurs, judging whether a first driving wheel and a second driving wheel are placed on the road surface And the target wheel spin is increased or decreased based on the determined road surface.

Also, if the determined road surface is a split road surface, the target wheel spin can be reduced if the determined road surface to increase the target wheel spin is a homonymous surface.

The embodiment of the present invention can quickly solve the hopping phenomenon generated during the traction control to improve the riding comfort of the driver.

1 is a control block diagram of a vehicle control apparatus according to an embodiment of the present invention.
2 is a diagram for explaining the operation of the electronic control unit in the vehicle control apparatus according to the embodiment of the present invention.
3 is a diagram for explaining control of P gain and I gain in hopping control on a split road surface in a vehicle control apparatus according to an embodiment of the present invention.
4 is a control flowchart for explaining hopping control on a split road surface in a vehicle control apparatus according to an embodiment of the present invention.
5 is a timing chart for hopping control on a split road surface in a vehicle control apparatus according to an embodiment of the present invention.
6 is a control flowchart for explaining hopping control on a homo plane in a vehicle control device according to an embodiment of the present invention.
7 is a timing diagram for hopping control on a homo planes in a vehicle control apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments to be described below are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of components are exaggerated for the sake of convenience. Like reference numerals designate like elements throughout the specification.

FIG. 1 is a control block diagram of a vehicle control apparatus according to an embodiment of the present invention, and FIG. 2 is a view for explaining operation of an electronic control unit in a vehicle control apparatus according to an embodiment of the present invention.

Referring to Figs. 1 and 2, the vehicle control apparatus may include an electronic control unit 10 that performs overall control.

On the input side of the electronic control unit 10, four wheel speed sensors 20 are electrically connected.

The braking force adjusting unit 30 and the driving force adjusting unit 40 are electrically connected to the output side of the electronic control unit 10.

Each wheel speed sensor 20 is provided on each wheel of the vehicle to detect the rotational speed of each wheel.

The braking force adjusting unit 30 controls the braking force of the vehicle by controlling the brake fluid pressure provided to the wheel cylinders provided on the respective wheels.

The driving force adjusting section 40 controls the engine torque of the vehicle to adjust the driving force of the vehicle.

The electronic control unit 10 adjusts the braking force of each wheel by decreasing, increasing or maintaining the brake fluid pressure supplied to each wheel cylinder through the braking force adjusting unit 30. [

The electronic control unit 10 adjusts the driving force of the driving wheels by controlling the engine torque of the vehicle through the driving force adjusting portion 40. [

When the traction control is started, the electronic control unit 10 adjusts the braking force of each wheel through the braking force adjusting unit 30 and controls the driving force of the driving wheel through the driving force adjusting unit 40 to perform traction control.

The electronic control unit 10 uses the wheel speed information sensed by the wheel speed sensor 20 in traction control to determine whether or not a hopping of the vehicle occurs.

The electronic control unit 10 calculates 'wheel speed amplitude', 'wheel speed cycle' and 'wheel speed versus vehicle speed' in traction control. The electronic control unit 10 can judge whether the calculated three values satisfy the reference condition for judging occurrence of the hopping. That is, the electronic control unit 10 determines whether the period of the wheel speed reaches the natural frequency range (for example, 6 to 11 Hz range) of the vehicle suspension, the amplitude thereof is equal to or greater than a predetermined amplitude value, It is determined that the hopping has occurred. At this time, if the hopping continuously occurs for three periods of the wheel speed from the time of occurrence of the hopping, it can be determined that the hopping has occurred.

The electronic control unit 10 detects the left driving wheel speed detected by the first wheel speed sensor for detecting the rotational speed of the left driving wheel at the time of traction control or when the hopping is generated and the rotational speed of the right driving wheel opposed to the left driving wheel The friction coefficient of the left and right road surface is recognized based on the right driving wheel speed detected by the second wheel speed sensor of the second wheel speed sensor and the traveling road surface can be determined based on the recognized friction coefficient of the left and right road surfaces.

The electronic control unit 10 can judge whether the running road surface is a split-mu surface with different left and right road surface friction coefficients (Split-mu) or a road surface other than a split road surface based on the recognized friction coefficients of the left and right road surfaces . The road surface other than the split road surface may include a homo-mu surface with little or no left and right road surface friction coefficient. In addition, road surface judgment can be implemented by various methods.

The electronic control unit 10 changes the target wheel spin so as to improve the ride comfort when the hopping occurs, and performs the hopping control to follow the current wheel spin to the changed target wheel spin to stabilize the vehicle from resonance. The electronic control unit 10 changes the target wheel spin according to whether the traveling road surface is a split road surface or a homonymous road at the time of occurrence of the hopping and performs hopping control to follow the current wheel spin to the changed target wheel spin to stabilize the vehicle from resonance Thereby improving ride comfort.

The electronic control unit 10 increases the target wheel spin so that the generated hopping can be resolved as soon as possible when the running road surface is a split road surface at the time of occurrence of the hopping.

3 is a diagram for explaining control of P gain and I gain in hopping control on a split road surface in a vehicle control apparatus according to an embodiment of the present invention.

Referring to FIG. 3, the electronic control unit 10 controls the braking force and the driving force of the vehicle so that the current wheel spin follows the increased target wheel spin during the hopping control on the split road surface. At this time, the electronic control unit 10 uses the proportional-integral (PI) control in the hopping control on the split road surface to follow the current wheel spin to the increased target wheel spin.

The electronic control unit 10 reduces the proportional gain (P gain) and the integral gain (I gain) when following the current wheel spin to the increased target wheel spin using the proportional-integral control . Thus, the proportional gain (P gain) is reduced and the integral gain (I gain) is increased to reduce the vibration of the wheel spin and increase the wheel spin.

Referring again to FIGS. 1 and 2, the electronic control unit 10 reduces the target wheel spin so that the generated hopping can be resolved as soon as possible when the running road surface is homonymous at the time of hopping.

The electronic control unit 10 controls the braking force and the driving force of the vehicle so that the current wheel spin is followed by the target wheel spin when the hopping control is performed on the homo plane. At this time, the electronic control unit 10 uses the proportional-integral (PI) control to control the current wheel spin to the reduced target wheel spin in hopping control on the homo plane.

The electronic control unit 10 determines that the generated hopping is canceled when the traction control ends, or when any of the wheel speed frequency, the amplitude, and the wheel speed relative to the vehicle speed exceeds the reference condition corresponding to the occurrence of the hopping.

The electronic control unit 10 holds the hopping control on the homo plane for a preset time period regardless of hopping elimination to prevent the hopping from recurring. That is, the electronic control unit 10 does not immediately terminate the hopping control even if the hopping is determined to be canceled, and maintains the hopping control for a preset time. P gain and I gain are increased when the spin error (Spin Error, target wheel spin-wheel spin) is a positive (+) value. This is because, when the target wheel spin is reduced, the torque can not be increased when the wheel spin is small, which may degrade acceleration performance. P gain and I gain are reduced when the spin error is negative (-) value. This is to reduce the vibration of the wheel spin.

The electronic control unit 10 releases the hopping control after maintaining the hopping control for a predetermined time from the point at which the hopping is resolved. That is, the reduced target wheel spin is changed to the original target wheel spin so that the traction control is performed according to the changed target wheel spin.

FIG. 4 is a control flow chart for explaining hopping control on a split road surface in a vehicle control apparatus according to an embodiment of the present invention, and FIG. 5 is a flowchart illustrating a control flow in a vehicle control apparatus according to an embodiment of the present invention, Lt; / RTI > is a timing diagram for hopping control.

Referring to FIG. 4, the electronic control unit 10 determines whether traction control (TCS control) is required (100), and performs traction control at time t1 when traction control is required (102). The electronic control unit 10 sets the target wheel spin during traction control and adjusts the braking force and the driving force so that the current wheel spin follows the set target wheel spin.

The electronic control unit 10 detects (104) each wheel speed through each wheel speed sensor 20 while performing the traction control, and determines (106) whether the hopping has occurred using the detected wheel speed.

When the hopping occurs at time t2, the electronic control unit 10 increases the target wheel spin from the target wheel spin value S0 at the hopping occurrence time to a preset spin value S1 (108). Accordingly, since the torque is generated by the method in which the present wheel spins follow the increased target wheel spin, the generated hopping can be resolved as soon as possible.

At the same time, when the electronic control unit 10 performs the PI control so that the current wheel spin follows the increased target wheel spin S1, the P gain is decreased from the P gain value P0 at the time of the hopping to P1, The I gain value I0 of the starting point is increased to I1 (110). As a result, the vibration of the wheel spin is reduced and the wheel spin is increased.

When the hopping is eliminated at time t3, the electronic control unit 10 sets the target wheel spin to the original target wheel spin S0 in the increased target wheel spin S1 (for example, Spin) (114).

At the same time, the electronic control unit 10 restores both the P gain and the I gain of the PI control in the same manner as the restoration of the target wheel spin (116).

FIG. 6 is a control flow chart for explaining a hopping control on a homo plane in a vehicle control apparatus according to an embodiment of the present invention, and FIG. 7 is a flowchart illustrating a hopping control on a homo plane in a vehicle control apparatus according to an embodiment of the present invention. Fig.

6, the electronic control unit 10 determines whether traction control (TCS control) is necessary (step 200). If traction control is necessary, the electronic control unit 10 performs traction control at time t1 (step 202) . The electronic control unit 10 sets the target wheel spin during traction control and adjusts the braking force and the driving force so that the current wheel spin follows the set target wheel spin.

The electronic control unit 10 detects (204) each wheel speed through each wheel speed sensor 20 while performing the traction control, and determines (206) if the hopping has occurred using the detected wheel speed.

When the hopping occurs at time t2, the electronic control unit 10 reduces the target wheel spin to the preset spin value S1 at the target wheel spin value S0 at the hopping occurrence time (208). Accordingly, since the torque is formed by the method in which the present wheel spins follow the reduced target wheel spin, the generated hopping can be resolved as soon as possible.

If the hopping is canceled at time t3, the electronic control unit 10 calculates the P / I gain obtained by vectorizing the P gain and the I gain from the predetermined time t3 to t4 by a spin error (Spin Error, (Wheel spin) is a positive (+) value or a negative (-) value. The P / I gain is incremented when the spin error is a positive (+) value and decreased when the spin error is a negative (-) value. 7 shows a case where the spin error is a positive (+) value. P gain is increased from the P / I gain value P / I_0 at the time of hopping to P / I_1 by increasing the P gain and the I gain.

The electronic control unit 10 restores 216 the target wheel spin from the reduced target wheel spin S1 to the original target wheel spin S0 when a predetermined time has elapsed at time t4.

At the same time, the electronic control unit 10 restores the P / I gain of the PI control in the same manner as the restoration of the target wheel spin (218).

10: Electronic control unit 20: Wheel speed sensor
30: braking force adjusting unit 40: driving force adjusting unit

Claims (9)

A first wheel speed sensor for detecting the speed of the first driving wheel;
A second wheel speed sensor for detecting the speed of the second driving wheel; And
And an electronic control unit for determining whether hopping occurs during traction control and controlling the braking force and driving force of the vehicle when the hopping occurs,
Wherein the electronic control unit determines a road surface on which the first driving wheel and the second driving wheel are placed and increases or decreases the target wheel spin based on the determined road surface. The method according to claim 1,
And the electronic control unit increases the target wheel spin if the determined road surface is a split road surface. 3. The method of claim 2,
Wherein the electronic control unit reduces the proportional gain (P gain) and increases the integral gain (I gain) when following the current spin to the increased target wheel spin using the proportional integral control. The method according to claim 1,
Wherein the electronic control unit reduces the target wheel spin if the determined road surface is a homonymous surface. 5. The method of claim 4,
Wherein the electronic control unit maintains the reduction of the target wheel spin during a hopping maintenance period from when the generated hopping is canceled until a predetermined time elapses. 6. The method of claim 5,
Wherein the electronic control unit controls the proportional gain (P gain) and the integral gain (I gain) when the spin error is a positive value when the current spin is followed by the reduced target wheel spin using the proportional integral control during the hopping maintenance period Increases the vectorized proportional / integral gain (P / I gain), and decreases the proportional / integral gain (P / I gain) if the spin error is a negative value. The method according to claim 1,
Wherein the period of the wheel speed detected by the first wheel speed sensor or the second wheel speed sensor reaches the natural frequency range of the suspension of the vehicle, and the amplitude of the detected wheel speed is equal to or greater than a predetermined amplitude value, And judges that the hopping has occurred when the detected wheel speed reaches a predetermined speed value corresponding to the vehicle speed. It is determined whether hopping occurs during traction control,
When the hopping occurs, the braking force and the driving force of the vehicle are controlled,
Judges a road surface where the first drive wheel and the second drive wheel are located,
And the target wheel spin is increased or decreased based on the determined road surface. 9. The method of claim 8,
And decreasing the target wheel spin if the determined road surface is a homonymous surface when the determined road surface is a split road surface.

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