KR101428376B1 - Apparatus for computing location of vehicle and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for calculating the position of a vehicle, and more particularly, to a suspension parameter measuring device (SPMD) characteristic curve showing a correlation between a steering angle and a front tire angle in an automatic parking system, And calculating a position of the vehicle in consideration of each angle so as to more accurately follow the parking locus at the time of automatic parking, and a method thereof.
To this end, the present invention provides a vehicle position calculating apparatus comprising: a steering angle-tire angle table in which a tire angle corresponding to a steering angle is recorded; A steering angle sensing unit for sensing a steering angle varying by the steering wheel; A slip angle calculating unit for calculating a slip angle after searching for a tire angle corresponding to the steering angle sensed by the steering angle sensing unit based on the steering angle-tire angle table; A micro-yaw angle calculating unit for calculating a micro-yaw angle based on the slip angle calculated by the slip angle calculating unit; And a position calculating unit for calculating a current position of the vehicle in which the micro-movement generated by the slip is reflected, based on the micro-yaw angle calculated by the micro-yaw angle calculating unit.

Description

[0001] APPARATUS FOR COMPUTING LOCATION OF VEHICLE AND METHOD THEREOF [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and method for calculating a position of a vehicle, and more particularly to a vehicle position calculating apparatus and method for calculating a position of a vehicle in consideration of a slip angle of a front tire, A position calculating device and a method thereof.

Generally, when an inexperienced novice driver, a female driver or an elderly person parks a vehicle in a narrow space, it is difficult to precisely predict an interval between a parked vehicle on both sides of a space to be parked, The vehicle is parked.

In this case, when the distance between the vehicle and the surrounding vehicle is incorrectly predicted, frequent occurrence of a contact accident with the already parked vehicle or the opening of the door of the vehicle frequently occurs due to a small distance from the surrounding vehicle. Especially, in the case of nighttime, it is much harder to park normally because securing a view through a side mirror or a back mirror is very difficult compared with a daytime.

A conventional automatic parking system for solving this problem generates a parking locus based on collected information using various sensors, and places the vehicle in a desired space while following the parking locus. At this time, the steering angle required to follow the parking trajectory is collected through the steering angle sensor.

Such a conventional automatic parking system has a problem in that it does not take into consideration an actual steering angle error caused by a slip (slip angle, slip ratio) of a vehicle according to road surface conditions, a tolerance of a steering angle and a wheel angle, There is a problem that it is difficult to follow the accurate parking trajectory because the parking trajectory is followed.

In order to solve the problems of the prior art as described above, the present invention relates to a suspension parameter measuring device (SPMD) characteristic curve showing a correlation between a steering angle and a front tire angle in an automatic parking system, And calculating the position of the vehicle in consideration of each angle, thereby enabling the parking locus to be more accurately followed in the automatic parking.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to another aspect of the present invention, there is provided an apparatus for calculating a position of a vehicle, comprising: a steering angle-tire angle table in which a tire angle corresponding to a steering angle is recorded; A steering angle sensing unit for sensing a steering angle varying by the steering wheel; A slip angle calculating unit for calculating a slip angle after searching for a tire angle corresponding to the steering angle sensed by the steering angle sensing unit based on the steering angle-tire angle table; A micro-yaw angle calculating unit for calculating a micro-yaw angle based on the slip angle calculated by the slip angle calculating unit; And a position calculating unit for calculating a current position of the vehicle in which the micro-movement generated by the slip is reflected, based on the micro-yaw angle calculated by the micro-yaw angle calculating unit.

According to another aspect of the present invention, there is provided a method for calculating a position of a vehicle, the method comprising: sensing a steering angle variable by a steering wheel sensing unit; Calculating a slip angle using a tire angle corresponding to the sensed steering angle; Calculating a micro-yaw angle based on the calculated slip angle; And calculating the current position of the vehicle in which the micro-movement generated by the slip is reflected using the calculated micro-yaw angle.

The present invention is not limited to the SPMD (Suspension Parameters Measuring Device) characteristic curve showing the correlation between the steering angle and the front tire angle in the automatic parking system, as well as the front slip angle caused by the steering angle when the vehicle is moving. It is possible to more accurately follow the parking locus at the time of automatic parking.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an apparatus for calculating a position of a vehicle according to an embodiment of the present invention;
FIG. 2 is an example of an SPMD characteristic curve according to the present invention,
FIG. 3 is an explanatory diagram of a front slip angle calculating process of a vehicle according to an embodiment of the present invention,
4 and 5 are views illustrating an example in which the vehicle according to the present invention is assumed to be a bicycle model,
6 is a flowchart of an embodiment of a method for calculating the position of a vehicle according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an apparatus for calculating a position of a vehicle according to an embodiment of the present invention.

1, the vehicle position calculating apparatus according to the present invention includes a steering angle-tire angle table 11, a steering angle sensing unit 12, a slip angle 13, a minute yaw angle calculating unit 14, And a position calculation section 15.

는 타이어각,

는 조향각,

은 좌측 전륜의 타이어각,

은 우측 전륜의 타이어각을 각각 의미한다.The steering angle-tire angle table 11 is a table in which a tire angle corresponding to the steering angle generated by the steering wheel is recorded. For example, the steering angle-tire angle table 11 includes an SPMD characteristic curve as shown in Fig. 2,

The tire angle,

The steering angle,

The tire angle of the left front wheel,

Represents the tire angle of the right front wheel, respectively.

In addition, SPMD refers to a vehicle basic characteristics tester, which is a hydraulic tester that measures the characteristics of a suspension by applying a force or a displacement to the wheel of the vehicle in the up / down / back / left / right direction.

Next, the steering angle sensing unit 12 is a kind of steering angle sensing sensor, which senses a steering angle that is varied by the steering wheel.

Next, the slip angle calculating unit 13 calculates the front slip angle using the tire angle corresponding to the steering angle sensed by the steering angle sensing unit 12, based on the steering angle-tire angle table 11. [

3 to 5, the process of calculating the front slip angle of the slip angle calculating unit 13, the process of calculating the minute yaw angle of the minute yaw angle calculating unit 14, the process of calculating the current yaw angle of the vehicle of the position calculating unit 15 The calculation process will be described in detail.

In FIG. 3, reference numeral 31 denotes a left front wheel, 32 denotes a right front wheel, 33 denotes a virtual front wheel located at the center of the left front wheel and the right front wheel, 34 denotes a left rear wheel, 36 " means a virtual rear wheel located at the center of the left rear wheel and the right rear wheel, respectively.

은 조향각,

는 타이어각,

는 전륜 슬립각,

는 미소 요각도, v_F는 전륜의 슬립각이 반영된 속도 벡터, L은 휠베이스로서 전륜 차축과 후륜 차축 간의 거리(상수),

는 x방향 미소 이동,

는 y방향 미소 이동을 각각 의미한다.In addition, l _RL is a left side travel of the rear wheel (31), l _RR is the moving distance of the rear wheel 32, the right side, l _RC is the moving distance of the rear wheels 36 of the virtual, R _RL is the turning of the left rear wheel 31, the radius , _RRR is the turning radius of the right rear wheel,

The steering angle,

The tire angle,

Front slip angle,

, V _F is a velocity vector reflecting the slip angle of the front wheel, L is a distance (constant) between the front wheel axle and the rear wheel axle as a wheel base,

X direction,

Represents a small movement in the y direction.

FIG. 4 is a diagram illustrating an example in which the vehicle according to the present invention is assumed to be a bicycle model.

는 전륜의 y좌표 성분의 미분값, v_R은 후륜의 슬립각이 반영된 속도 벡터 ,

은 후륜의 y좌표 성분의 미분값을 각각 의미한다.4, (x _F , y _F ) is the xy coordinate of the front wheel, (x _R , y _R ) is the xy coordinate of the rear wheel, v _F is the velocity vector reflecting the slip angle of the front wheel,

Is a differential value of the y coordinate component of the front wheels, _R v is the velocity vector of the rear wheel slip angle is reflected,

Denotes the differential value of the y coordinate component of the rear wheel.

를 만족한다.Here, assuming that the vehicle is a bicycle model to obtain the slip angle,

.

In Figure 5, _F is the wheel speed wss, wss _R of the front wheel sensor measurements hwilsok Thai traveling direction refers to the wheel speed of the rear wheel tire proceeds hwilsok sensor measurement direction.

에 하기의 [수학식 1]을 대입하여 하기의 [수학식 2]와 같은 전륜 슬립각(

)의 산출식을 구한다.

The following equation (1) is substituted for the front slip angle (

) Is calculated.

[Equation 1]

&Quot; (2) "

)은

를 만족한다.At this time,

)silver

.

Next, the micro-yaw angle calculating section 14 calculates the micro-yaw angle based on the slip angle calculated by the slip angle calculating section 13. That is, the micro-yaw angle calculating section 14 calculates the micro-yaw angle using the following equation (3) established by the Ackerman-Geometry relationship.

&Quot; (3) "

)를 산출한다. 즉, 위치 산출부(15)는 하기의 [수학식 4]를 이용하여 차량의 현재 위치를 산출한다.Next, the position calculating section 15 calculates the position ( _xVnew , _yVnew , _yVnew) of the vehicle in which the micro-movement generated by the slip is reflected, based on the micro-yaw angle calculated by the micro-yaw angle calculating section 14,

). That is, the position calculating unit 15 calculates the current position of the vehicle using the following equation (4).

&Quot; (4) "

는 차량의 직전 위치의 요각도를 각각 의미한다.Here, _xVold is the x coordinate of the position immediately before the vehicle, _yVold is the y coordinate of the position immediately before the vehicle,

Means the yaw angle of the position immediately before the vehicle.

≒ l_{RC =} (l_RL + l_RR)/2를 만족하고,

≒ 0을 만족한다.Also,

= L _{RC =} (1 _RL + 1 _RR ) / 2,

? 0.

6 is a flowchart of an embodiment of a method for calculating the position of a vehicle according to the present invention.

First, the steering angle sensing unit 12 senses a steering angle that is varied by the steering wheel (601).

Then, the slip angle calculating unit 13 calculates the slip angle using the tire angle corresponding to the steering angle sensed by the steering angle sensing unit 12 (602).

Subsequently, the micro-yaw angle calculating section 14 calculates the micro-yaw angle based on the slip angle calculated by the slip angle calculating section 13 (603).

Subsequently, the position calculating unit 15 calculates the current position of the vehicle in which the micro-movement generated by the slip is reflected (604) based on the micro-yaw angle calculated by the micro-yaw angle calculating unit 14. [

By accurately calculating the position of the vehicle through this process, it is possible to follow the parking locus more accurately in the automatic parking.

Meanwhile, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily deduced by a computer programmer in the field. In addition, the created program is stored in a computer-readable recording medium (information storage medium), and is read and executed by a computer to implement the method of the present invention. And the recording medium includes all types of recording media readable by a computer.

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 scope of the invention. The present invention is not limited to the drawings.

11: Steering angle - Tire angle table 12: Steering angle sensor
13: slip angle calculating section 14: micro-yaw angle calculating section
15:

Claims (5)

A steering angle-tire angle table in which a tire angle corresponding to the steering angle is recorded;
A steering angle sensing unit for sensing a steering angle varying by the steering wheel;
A slip angle calculating unit for calculating a slip angle after searching for a tire angle corresponding to the steering angle sensed by the steering angle sensing unit based on the steering angle-tire angle table;
A micro-yaw angle calculating unit for calculating a micro-yaw angle based on the slip angle calculated by the slip angle calculating unit; And
Based on the micro-yaw angle calculated by the micro-yaw angle calculating section, calculates a current position of the vehicle in which the micro-movement generated by the slip is reflected,
And calculates a position of the vehicle.
The method according to claim 1,
Wherein the slip angle calculating unit calculates,
The front slip angle < RTI ID = 0.0 > ((A)

) Of the vehicle.
[Mathematical formula A]

here,

Wss _F is the wheel speed in the tire traveling direction measured by the front wheel acceleration sensor, and wss _R is the wheel speed in the tire traveling direction measured by the rear wheel acceleration sensor.
3. The method of claim 2,
Wherein the micro-
The micro-yaw angle ((B)

) Of the vehicle.
[Mathematical expression B]

Here, l _RC = (The travel distance of the left rear wheel + the travel distance of the right rear wheel) / 2, and L denotes the wheel base.
The method of claim 3,
The position calculating unit calculates,
( _XVnew , _yVnew , _yVnew , _yVnew , _yVnew , _yVnew) using the following formula (C)

) Of the vehicle.
[Mathematical expression C]

Here, _xVold is the x coordinate of the position immediately before the vehicle, _yVold is the y coordinate of the position immediately before the vehicle,

Respectively indicate the yaw angle of the position immediately before the vehicle,

Lt; / RTI > _RC ,

? 0.
Sensing a steer angle that is varied by the steering angle sensor;
Calculating a slip angle using a tire angle corresponding to the sensed steering angle;
Calculating a micro-yaw angle based on the calculated slip angle; And
The position calculating unit calculates the present position of the vehicle in which the micro-movement generated by the slip is reflected using the calculated micro-yaw angle
Of the vehicle.

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