KR20130132149A - Apparatus and method for control of wheel - Google Patents

Abstract

The present invention relates to a method for controlling a wheel, which calculates a slip angle using information on force applying to a tire that measured by an intelligent tire, and controls a wheel using the calculated slip angle. An apparatus for controlling a wheel prepared by the present invention comprises an information receiving unit which receives information on force applying to a tire from an intelligent tire; a slip angle calculating unit which calculates the slip angle of at least one between a front wheel and a back wheel of tires using the received information; and a characteristic drawing unit which draws information on at least one among wheel control time, a wheel control amount, a wheel to be controlled, a turning direction of a vehicle, turning characteristics of the vehicle, and an oversteer state of an understeer state using the calculated slip angle. [Reference numerals] (100) Wheel control apparatus;(110) Information receiving unit;(112) Intelligent tire information receiving unit;(114) Steering angle sensor information receiving unit;(120) Slip angle calculating unit;(130) Characteristic drawing unit;(140) Control unit

Description

TECHNICAL FIELD [0001] The present invention relates to a wheel control apparatus,

The present invention relates to a wheel control apparatus and method. More particularly, the present invention relates to a wheel control apparatus and method for calculating a slip angle using information about a force applied to a tire measured by an intelligent tire, and controlling the wheel using the calculated slip angle.

The turning stability control technique of the vehicle is to calculate the turning characteristic of the vehicle by using a yaw rate sensor which is a sensor for measuring a rotational angular speed mounted on the vehicle body or a lateral acceleration sensor which is a sensor for measuring a lateral acceleration, , And controls the wheels.

In order to apply such control technology to the vehicle, various sensors such as a yaw rate and a lateral acceleration sensor are required in the vehicle, and an observer design is also required.

According to an aspect of the present invention, there is provided a wheel control apparatus comprising: an information receiving unit for receiving information on a force applied to a tire from an intelligent tire; A slip angle calculating unit for calculating a slip angle of at least one of a front wheel and a rear wheel of the tire using the received information; And calculating at least one of at least one of a wheel control point, a wheel control amount, a controlled wheel, a turning direction of the vehicle, a turning characteristic of the vehicle, an oversteer state, or an understeer state using the calculated slip angle And a characteristic deriving unit for deriving a characteristic curve.

Preferably, the information receiving unit receives information about the steering angle from the steering angle sensor, and the characteristic deriving unit may calculate at least one of the turning direction of the controlled wheel or the vehicle using the information about the received steering angle And one information is derived.

Preferably, the wheel control apparatus further includes a controller for controlling the wheel using the information derived from the characteristic derivation unit.

Preferably, the information about the force applied to the tire received by the information receiving unit includes information about the tire lateral force and the cornering rigidity value, and the slip angle calculating unit calculates the tire lateral force and the cornering rigidity And the lateral slip angle is calculated by using information on the value of the lateral slip angle.

Preferably, the cornering stiffness value is a value in consideration of a change gain of at least one of the front wheels or the rear wheels, and the change gain of the normal force is a vertical force of at least one of the front wheels or the rear wheels in a static state, Wherein the slip angle calculating unit calculates a slip angle using a cornering rigidity value that takes into account a change gain of the tire lateral force and the vertical force, .

Preferably, the slip angle calculating unit calculates lateral slip angles of the front wheels and the rear wheels, and the turning characteristic derived from the characteristic deriving unit is a difference between the calculated lateral slip angle of the front wheel and the calculated lateral slip angle of the rear wheel .

Preferably, the slip angle calculating unit calculates the lateral slip angles of the front wheels and the rear wheels, and the control amount derived from the characteristic deriving unit is a predetermined threshold value in the difference between the lateral slip angle of the front wheel and the lateral slip angle of the rear wheel And the difference between the two values is used.

Preferably, the control amount is optimally distributed to the front wheel and the rear wheel using the normal force to derive the control amount of each wheel.

According to another aspect of the present invention, there is provided a wheel control method comprising: receiving information on a force applied to a tire measured by an intelligent tire; A slip angle calculating step of calculating a slip angle of at least one of a front wheel and a rear wheel of the tire using the received information; And calculating at least one of at least one of a wheel control point, a wheel control amount, a controlled wheel, a turning direction of the vehicle, a turning characteristic of the vehicle, an oversteer state, or an understeer state using the calculated slip angle And a characteristic extracting step of deriving a characteristic to be derived.

Preferably, the information receiving step receives information on the steering angle from the steering angle sensor, and the deriving of the characteristic may be performed using the information on the received steering angle, And at least one piece of information is derived.

Preferably, the wheel control method further includes a control step of controlling the wheel using the information derived in the characteristic deriving step.

Preferably, the information about the force applied to the tire received by the information receiving step includes information about the tire lateral force and the cornering stiffness value, and the slip angle calculating step calculates the slip angle based on the tire lateral force And a cornering rigidity value to calculate a lateral slip angle.

Preferably, the cornering stiffness value is a value in consideration of a change gain of at least one of the front wheels or the rear wheels, and the change gain of the normal force is a vertical force of at least one of the front wheels or the rear wheels in a static state, Wherein the slip angle calculating step calculates the slip angle using a cornering stiffness value that takes into account a change gain of the tire lateral force and the vertical force, .

Preferably, the slip angle calculating step calculates the lateral slip angles of the front wheels and the rear wheels, and the turning characteristic derived from the characteristic deriving step is a difference between the calculated lateral slip angle of the front wheel and the calculated lateral slip angle of the rear wheel .

Preferably, the slip angle calculating step calculates the lateral slip angles of the front wheels and the rear wheels, and the control amount derived from the characteristic deriving step is a predetermined threshold value in terms of the difference between the lateral slip angle of the front wheel and the lateral slip angle of the rear wheel. And a difference between the first and second threshold values.

Preferably, the control amount is optimally distributed to the front wheel and the rear wheel using the normal force to derive the control amount of each wheel.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a wheel control apparatus and a wheel control method for controlling a wheel by using a slip angle calculated using information about a force applied to a tire measured by an intelligent tire And to provide a device method.

The present invention can improve the turning stability of the vehicle by controlling the wheels of the vehicle without using the yaw rate and lateral acceleration sensors.

Further, the present invention reduces the amount of computation for controlling the wheels of the vehicle, thereby enabling more real-time control.

Further, the present invention can enhance the performance by imparting robustness to the parameter change by directly using the tire force.

1 is a block diagram of a wheel control apparatus according to a preferred embodiment of the present invention.
2 is a graph showing the relationship between the lateral slip angle, the tire lateral force and the cornering stiffness value.
3 is a block diagram showing an example of a characteristic deriving unit of the wheel control apparatus according to the present invention.
4 is a diagram illustrating an example of a method for determining turning characteristics of a vehicle according to the turning characteristic determining unit of the present invention.
5 is a flowchart of a wheel control method according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description and the accompanying drawings, substantially the same components are denoted by the same reference numerals, respectively, and redundant description will be omitted. 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.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

1 is a block diagram of a wheel control apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 1, a wheel control apparatus 100 includes an information receiving unit 110, a slip angle calculating unit 120, a characteristic deriving unit 130, and a controller 140.

The information receiving unit 110 receives information used for calculating information required for wheel control.

Specifically, the information receiving unit 110 includes an intelligent tire information receiving unit 112 and a steering angle sensor information receiving unit 114.

The intelligent tire information receiving unit 112 receives information about the force acting on the tire measured by the intelligent tire of the vehicle.

Intelligent tires can measure the force acting on a tire. For example, an intelligent tire can measure the force acting on a tire by checking the tire air pressure change in real time or from time to time. The information about the force acting on the tire measured by the intelligent tire is transmitted to the intelligent tire information reception number by wire or wirelessly.

The information about the force applied to the tire received by the intelligent tire information receiving unit 112 includes information such as a tire lateral force, a cornering rigidity value, a vertical force acting on the front wheel, and a vertical force acting on the rear wheel, All of which are indirectly acted through.

The steering angle sensor information receiving unit 114 receives the information about the steering angle of the vehicle collected by the steering angle sensor by wire or wirelessly.

The slip angle calculating unit 120 calculates a slip angle using information about a force applied to the tire received by the information receiving unit 110. [

Specifically, the slip angle calculating unit 120 may calculate the lateral slip angle using the tire lateral force, the cornering stiffness value, the vertical force acting on the front wheel, and the vertical force acting on the rear wheel received by the intelligent tire information receiving unit 112.

2 is a graph showing the relationship between the lateral slip angle, the tire lateral force and the cornering stiffness value.

Referring to FIG. 2, the tire lateral force can be defined as a product of a cornering stiffness value and a lateral slip angle in a linear section. This can be expressed as Equation (1).

f는 전륜에 관한 횡슬립각이고,

r은 후륜의 횡슬립각이다.Fyf is the tire lateral force with respect to the front and Fyr is the tire lateral force with respect to the rear wheel. Cf is the cornering stiffness value for the front wheel, and Cr is the cornering stiffness value for the rear wheel.

f is the lateral slip angle with respect to the front wheel,

and r is the lateral slip angle of the rear wheel.

The cornering stiffness value can be defined as the slope of the lateral force and the lateral slip angle in the linear section as shown in FIG. 2, and the greater the vertical force, the greater the lateral force of the tire.

In general, the transverse slip angle is defined as the cornering stiffness coefficient of the static state with a slope in a small section (linear section). In this case, the lateral force can be expressed as a product of the cornering stiffness coefficient and the lateral slip angle have.

The cornering stiffness value can be corrected in consideration of the change gain of the normal force, and in this case, the tire lateral force can be expressed by the following equation (2).

Fzfg is the force acting on the front wheel, and Fzrg is the normal force acting on the rear wheel.

The vertical force change gain of the front wheel and the rear wheel can be calculated by using the ratio between the normal force of the front wheel and the rear wheel measured in the intelligent tire according to the normal force and the turning behavior of the front wheel and the rear wheel in the static state.

The transverse slip angles of the front wheel and the rear wheel can be calculated using the lateral force and the corrected cornering stiffness value.

This can be expressed as Equation (3).

f는 전륜에 작용되는 타이어 횡력을 전륜에 작용되는 수직력의 변화 게인과 전륜에 작용되는 코너링 강성 값간의 곱으로 나눈 것이 된다.Referring to Equation (3), the lateral slip angle

f is the tire lateral force acting on the front wheel divided by the product of the change gain of the normal force acting on the front wheel and the cornering stiffness value acting on the front wheel.

r는 후륜에 작용되는 타이어 횡력을 후륜에 작용되는 수직력의 변화 게인과 후륜에 작용되는 코너링 강성 값간의 곱으로 나눈 것이 된다.The lateral slip angle acting on the front wheel

r is the tire lateral force acting on the rear wheel divided by the product of the change gain of the normal force acting on the rear wheel and the cornering stiffness value acting on the rear wheel.

The characteristic derivation unit 130 calculates the slip angle using the lateral slip angle calculated by the slip angle calculation unit 120 and the steering angle information received from the steering angle information receiving unit to calculate a wheel control point, a wheel control amount, a controlled wheel, The oversteer state, the understeer state, and the understeer state of the vehicle.

3 is a block diagram showing an example of a characteristic deriving unit of the wheel control apparatus according to the present invention.

3, the characteristic derivation unit 130 includes a turning direction calculation unit 131, a turning characteristic determination unit 132, an excessive steering state calculation unit 133, A steered state calculating unit 134, a controlled object determining unit 135, a control time calculating unit 136, and a control amount calculating unit 137. [

The turning direction calculating section 131 can calculate the turning direction of the vehicle based on the steering angle information received by the steering angle information receiving section.

Specifically, the turning characteristic determining unit 132 determines the turning characteristics of the vehicle by using the lateral slip angle of the front wheel and the lateral slip angle of the rear wheel calculated by the slip angle calculating unit 120. [

In the conventional case, the turning characteristic of the vehicle is determined based on the difference between the actual yaw rate and the actual yaw rate, which is the target yaw rate calculated by the steering angle generated in accordance with the driver's steering angle.

The turning characteristic determining unit 132 of the present invention determines the turning characteristic based on the difference between the lateral slip angle of the front wheel and the lateral slip angle of the rear wheel calculated by the slip angle calculating unit 120. [

4 is a diagram illustrating an example of a method for determining turning characteristics of a vehicle according to the turning characteristic determining unit of the present invention.

More specifically, referring to Fig. 4, when the front wheel lateral slip angle calculated on the graph is larger than the rear wheel lateral slip angle, i.e., when the rear wheel slip angle is subtracted from the front wheel lateral slip angle, It is determined that the vehicle is understeer. Conversely, when the frontal slip angle calculated on the graph is smaller than the rear-wheel lateral slip angle, that is, when the rear-wheel lateral slip angle is negative in the frontal slip angle, it is determined that the vehicle is in an oversteer state.

The excessive steering state calculation unit 133 can determine whether the excessive steering state is obtained by using the difference between the front wheel lateral slip angle and the rear wheel lateral slip angle as determined by the turning characteristic determination unit 132. In the excessive steering state, The degree of the excessive steering state can be calculated using the difference degree of the angle.

As determined by the turning characteristic determining unit 132, the under-steering state calculating unit 134 can determine whether the under-steering state is a state using the difference between the front-side slip angle and the rear-wheel lateral slip angle. In the under- The degree of the under-steered state can be calculated using the difference degree of the angle.

The controlled object determining unit 135 can determine the wheels requiring control by using the slip angles of the front and rear wheels calculated by the slip angle calculating unit 120 and the steering angle information received by the steering angle information receiving unit.

Specifically, the controlled object determining unit 135 determines whether or not the control object determining unit 135 has determined that the turning object is in the turning state determined by the turning characteristic determining unit 132 based on the turning direction of the vehicle calculated by the turning direction calculating unit 131 and the calculated slip angle using the received steering angle information It is possible to determine the left or right wheel to be controlled by using the turning characteristics of the vehicle.

The control time determiner 136 determines the time when the wheel control of the vehicle is required using the information determined or calculated by the turning characteristic determiner 132, the excessive steering state calculator 133 or the understeered state calculator 134 It can be judged.

The control amount calculating unit 137 may calculate the control amount of the wheel by using the slip angle of the front wheel and the rear wheel calculated by the slip angle calculating unit 120 and a tuning variable set in advance.

An example of how the control amount calculating unit 137 calculates the control amount of the wheel will be described in detail with reference to equations (4) and (5).

를 제동토크 단위로 환산하기 위한 토크 변환 게인이다.

는 전륜의 횡슬립각과 후륜의 횡슬립각의 차이와 미리 설정된 임계값인 튜닝변수 threshold값간의 차이가 될 수 있다.Equation (4) is a mathematical expression relating to the control amount of the wheel calculated by the control amount calculating unit 137. [ Tcg

In terms of braking torque unit.

May be the difference between the difference between the lateral slip angle of the front wheel and the lateral slip angle of the rear wheel and the tuning variable threshold value which is a preset threshold value.

The control amount calculating unit 137 can calculate the control amount distributed to the front wheel and the rear wheel using the control amount of the wheel calculated using the equation (4). This can be expressed as Equation (5).

Fzf is the vertical force acting on the front wheel, and Fzr is the vertical force acting on the rear wheel.

The control unit 140 controls the wheels using the information derived from the characteristic derivation unit 130.

The control unit 140 may be directly connected to the wheel or may be connected indirectly. The connection may be a mechanical connection, an electrical connection through a wire, etc., or may be controlled using a control signal for controlling the wheel through a wireless connection using wireless communication.

The wheel control apparatus 100 according to the present invention can calculate the tire slip angle of the front wheel or the rear wheel in real time using the information about the force such as the vertical force or the lateral force received by the tire, It is possible to appropriately control the wheel by grasping the turning characteristics and the like.

The wheel control apparatus 100 according to the present invention can improve the turning stability of the vehicle by controlling the wheels of the vehicle without using the yaw rate and lateral acceleration sensors.

Further, the wheel control apparatus 100 according to the present invention can reduce the calculation amount for controlling the wheels of the vehicle, thereby enabling more real-time control.

In addition, the wheel control apparatus 100 according to the present invention can enhance the performance by imparting robustness to the parameter change by directly using the tire force.

5 is a flowchart of a wheel control method according to a preferred embodiment of the present invention.

Referring to FIG. 5, the information receiving unit 110 receives information about the force acting on the tire from the intelligent tire and steering angle information from the steering angle sensor (step S510).

The slip angle calculating unit 120 calculates the slip angle using the information about the force applied to the received tire (step S520).

The characteristic derivation unit 130 calculates and determines characteristic information that may be needed for wheel control using the calculated slip angle and received steering angle information (step S530).

The characteristic information that may be required for the wheel control may be information of at least one of a wheel control point, a wheel control point, a wheel to be controlled, a turning direction of the vehicle, a turning characteristic of the vehicle, an oversteer state, or an understeer state .

The control unit 140 controls the wheel using the calculated characteristic information (step S540).

The wheel control apparatus 100 according to the present invention can calculate the tire slip angle of the front wheel or the rear wheel in real time using the information about the force such as the vertical force or the lateral force received by the tire, It is possible to appropriately control the wheel by grasping the turning characteristics and the like.

The wheel control method according to the present invention can improve the turning stability of the vehicle by controlling the wheels of the vehicle without using the yaw rate and lateral acceleration sensors.

In addition, the wheel control method according to the present invention can reduce the calculation amount for controlling the wheels of the vehicle, thereby realizing more real-time control.

Further, the wheel control method according to the present invention can enhance the performance by imparting robustness to the parameter change by directly using the tire force.

It should be understood that the block diagram of the wheel control apparatus 100 according to the preferred embodiment of the present invention represents exemplary conceptual aspects embodying the principles of the invention. Similarly, all of the flowcharts should be understood to represent various processes that may be substantially represented on a computer-readable medium and executed by a computer or processor, whether the computer or processor is explicitly shown.

The functions of the various elements shown in the drawings, including the functional blocks shown in a processor or similar concept, may be provided by use of dedicated hardware as well as hardware capable of executing software in connection with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, a single shared processor, or a plurality of individual processors, some of which may be shared.

Also, the explicit use of terms such as processor, control, or similar concepts should not be interpreted exclusively as hardware capable of running software, and may be used without limitation as a digital signal processor (DSP) (ROM), random access memory (RAM), and non-volatile memory. Other hardware may also be included.

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . 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.

Claims (16)

An information receiving unit for receiving information on a force acting on the tire from the intelligent tire;
A slip angle calculating unit for calculating a slip angle of at least one of a front wheel and a rear wheel of the tire using the received information; And
The calculated slip angle is used to derive information of at least one of a wheel control point, a wheel control amount, a controlled wheel, a turning direction of the vehicle, a turning characteristic of the vehicle, an oversteer state, or an understeer state And a characteristic deriving unit for deriving the characteristic of the wheel. The method according to claim 1,
Wherein the information receiving unit receives information about the steering angle from the steering angle sensor,
Wherein the characteristic derivation unit derives information of at least one of a control target wheel or a turning direction of the vehicle using the information about the received steering angle. The method according to claim 1,
The wheel control device includes:
And a controller for controlling the wheel using information derived from the characteristic derivation unit. The method according to claim 1,
Wherein the information about the force applied to the tire received by the information receiving unit includes information about the tire lateral force and the cornering rigidity value,
Wherein the slip angle calculating unit calculates the transverse slip angle using the information about the tire lateral force and the cornering rigidity value received by the information receiving unit. 5. The method of claim 4,
The cornering stiffness value is a value that takes into account the change gain of the vertical force of at least one of the front wheel and the rear wheel,
Wherein the change gain of the vertical force is a value calculated as a ratio between a normal force of at least one of the front wheel or the rear wheel in a static state and a vertical force of at least any one of the front wheel and the rear wheel measured by the intelligent tire in a turning behavior,
Wherein the slip angle calculating unit calculates the slip angle using a cornering stiffness value in consideration of the tire lateral force and the change gain of the vertical force. The method according to claim 1,
Wherein the slip angle calculating unit calculates lateral slip angles of the front wheel and the rear wheel,
Wherein the turning characteristic derived from the characteristic derivation unit is derived using a difference between the calculated lateral slip angle of the front wheel and the calculated lateral slip angle of the rear wheel. The method according to claim 1,
Wherein the slip angle calculating unit calculates lateral slip angles of the front wheel and the rear wheel,
Wherein the control amount derived from the characteristic derivation unit is derived using a difference between a lateral slip angle of the front wheel and a lateral slip angle of the rear wheel and a preset threshold value. 8. The method of claim 7,
Wherein the control amount is optimally distributed to the front wheel and the rear wheel using a normal force to derive a control amount of each wheel. An information receiving step of receiving information on a force acting on the tire from the intelligent tire;
A slip angle calculating step of calculating a slip angle of at least one of a front wheel and a rear wheel of the tire using the received information; And
The calculated slip angle is used to derive information of at least one of a wheel control point, a wheel control amount, a controlled wheel, a turning direction of the vehicle, a turning characteristic of the vehicle, an oversteer state, or an understeer state And a characteristic deriving step of deriving a characteristic of the wheel. 10. The method of claim 9,
Wherein the information receiving step receives information on the steering angle from the steering angle sensor,
Wherein the characteristic deriving step derives information of at least one of a control target wheel or a turning direction of the vehicle using the information about the received steering angle. 10. The method of claim 9,
The wheel control method includes:
And controlling the wheel using the information derived from the characteristic deriving step. 10. The method of claim 9,
Wherein the information on the force applied to the tire received by the information receiving step includes information on the tire lateral force and the cornering stiffness value,
Wherein the slip angle calculating step calculates the lateral slip angle using the information about the tire lateral force and the cornering stiffness value received in the information receiving step. 13. The method of claim 12,
The cornering stiffness value is a value that takes into account the change gain of the vertical force of at least one of the front wheel and the rear wheel,
Wherein the change gain of the vertical force is a value calculated as a ratio between a normal force of at least one of the front wheel or the rear wheel in a static state and a vertical force of at least any one of the front wheel and the rear wheel measured by the intelligent tire in a turning behavior,
Wherein the slip angle calculating step calculates the slip angle using a cornering stiffness value in consideration of the tire lateral force and the change gain of the vertical force. 10. The method of claim 9,
Wherein the slip angle calculating step calculates lateral slip angles of the front wheel and the rear wheel,
Wherein the turning characteristic derived from the characteristic deriving step is derived using the difference between the calculated lateral slip angle of the front wheel and the calculated lateral slip angle of the rear wheel. 10. The method of claim 9,
Wherein the slip angle calculating step calculates lateral slip angles of the front wheel and the rear wheel,
Wherein the control amount derived from the characteristic deriving step is derived by using a difference between a lateral slip angle of the front wheel and a lateral slip angle of the rear wheel and a preset threshold value. 16. The method of claim 15,
Wherein the control amount is optimally distributed to the front wheel and the rear wheel using a normal force to derive a control amount of each wheel.

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