KR20160077614A - Correcting methode of neutral position in four wheel steering system and apparatus using the same - Google Patents

Abstract

According to one embodiment of the present invention, a method for correcting a neutral position of a four-wheel steering device comprises: a first step of enabling an electronic control unit to obtain a first moving trajectory and a second moving trajectory in accordance with driving of a vehicle when a handle is set to be neutral; and a second step of enabling the electronic control unit to correct a stroke difference between a front wheel steering actuator and a rear wheel steering actuator of the vehicle based on the first moving trajectory and the second moving trajectory. Information of the first moving trajectory is obtained by a sensor mounted in the vehicle, and the information of the second moving trajectory is obtained by a GPS receiver mounted in the vehicle.

Description

TECHNICAL FIELD [0001] The present invention relates to a neutral position correcting method for a four-wheel steering apparatus, and a neutral position correcting apparatus for a four-

More particularly, the present invention relates to a method of correcting a neutral position of a four-wheel steering apparatus and a device for correcting a neutral position of a four-wheel steering apparatus using the same.

Generally, the vehicle is provided with a steering device for converting the rotational motion of the steering wheel to the turning motion of the wheel so that the traveling direction of the vehicle can be changed according to the intention of the driver. Steering devices for such vehicles are classified as passive steering systems and power steering systems.

BACKGROUND ART [0002] In recent years, an electric power steering (EPS) system has been proposed as a steering apparatus for a vehicle, in which the steering force of a steering wheel is controlled by electronic control according to a traveling speed to provide a driver with high- . The EPS system drives the motor by electronic control to lighten the steering force when parking or at low speeds, and to make the steering force heavy at high speeds.

Particularly, when the electric power steering system described above is applied to a four-wheel drive vehicle, front and rear wheel steering actuators that respectively control the steering of the front and rear wheels of the vehicle are provided. In this case, due to the stroke difference between the front and rear wheel steering actuators, There is a possibility that the vehicle adjustability and the driving convenience of the vehicle may be deteriorated.

The following prior art document discloses the technical content of providing a method for aligning a position sensor of a vehicle with a steerable wheel and does not include the technical gist of the present invention.

Japanese Unexamined Patent Application Publication No. 2003-95125A

The neutral position correcting method of a four-wheel steering apparatus according to an embodiment of the present invention and the apparatus for correcting neutral position of a four-wheel steering apparatus according to another embodiment are intended to solve the above-mentioned problems.

A neutral position correction method and correction device for a four-wheel steering apparatus capable of correcting a front / rear wheel steering mechanism by judging a neutral position of a front / rear wheel actuator by a straight path of a vehicle in a front / rear wheel steerable four- do.

The solution to the problem of the present invention is not limited to those mentioned above, and other solutions not mentioned can be clearly understood by those skilled in the art from the following description.

A method for correcting a neutral position of a four-wheel steering apparatus according to an embodiment of the present invention includes: a first step of acquiring a first movement locus and a second locus locus according to travel of the vehicle when the steering wheel is set to a neutral state; And a second step of the electronic control unit correcting the stroke difference between the front wheel steering actuator and the rear wheel steering actuator of the vehicle based on the first moving locus and the second moving locus, , And the second moving locus information is obtained by a GPS receiver mounted on the vehicle.

Preferably, the sensor is at least one of a steering angle sensor, a wheel speed sensor and a lateral acceleration sensor.

The first step may include a first step of determining whether the handle is neutral or not; And a 1-2 step of determining whether the vehicle has moved over a predetermined distance.

The second step includes: a second step of the electronic control unit comparing the first moving trajectory and the second moving trajectory; A second step (2-2) in which the electronic control unit calculates a deviation value between the first moving locus and the second moving locus and a moving distance of the vehicle based on the comparison result; A second step of the electronic control unit calculating a correction angle based on the deviation value and the moving distance of the vehicle; And (2-4) in which the electronic control unit corrects the stroke difference between the front wheel steering actuator and the rear wheel steering actuator of the vehicle based on the correction angle.

An apparatus for correcting neutral position of a four-wheel steering apparatus according to another embodiment of the present invention includes: a front wheel steering actuator for steering a front wheel of a vehicle; A rear wheel steering actuator for steering a rear wheel of the vehicle; An electronic control unit for controlling the front wheel steering actuator and the rear wheel steering actuator; A sensor for detecting a behavior of the vehicle; And a GPS receiver for receiving a GPS signal including movement information of the vehicle, wherein the electronic control unit is operable to receive the GPS signal based on the information transmitted from the sensor and the GPS receiver, The stroke difference between the steering actuator and the rear wheel steering actuator is corrected.

Wherein the electronic control unit obtains a first moving locus and a second locus locus corresponding to the running of the vehicle at the time of neutral setting of the handle from the sensor and the GPS receiver, It is preferable to correct the stroke difference between the front wheel steering actuator and the downhill steering actuator based on the difference.

Preferably, the electronic control unit determines whether or not the handle is neutral, and determines whether the vehicle has moved a predetermined distance or more.

The electronic control unit compares the first movement locus and the second movement locus, calculates a deviation value between the first movement locus and the second locus locus and a travel distance of the vehicle based on the comparison result, It is preferable that the correction angle is calculated based on the deviation value and the moving distance of the vehicle and the stroke difference between the front wheel steering actuator and the rear wheel steering actuator of the vehicle is corrected based on the correction angle.

The sensor is preferably at least one of a steering angle sensor, an optical sensor, a wheel speed sensor and a lateral acceleration sensor.

The steering device neutral position correcting method according to an embodiment of the present invention and the steering device neutral position correcting device according to another embodiment are based on a straight line trajectory of a vehicle obtained through a GPS receiver and a sensor mounted on a vehicle, / The self-correction of the rear wheel actuator is performed, it is possible to improve the control accuracy when the vehicle turns.

In addition, it is possible to expect the effect of improving the vehicle adjustability and the driving convenience of the driver.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned may be clearly understood by those skilled in the art from the following description.

1 is a flowchart illustrating a method of correcting a neutral position of a four-wheel steering apparatus according to an embodiment of the present invention.
Fig. 2 is a flowchart showing the subdivision of Fig.
3 is a conceptual diagram for explaining the details of calculating the correction angle in the neutral position correction method of the four-wheel steering apparatus according to the embodiment of the present invention.
4 is a block diagram briefly showing an apparatus for correcting a neutral position of a four-wheel steering apparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

Hereinafter, a method of correcting a neutral position of a four-wheel steering apparatus according to an embodiment of the present invention will be described in detail with reference to FIG. 4 before briefly describing configurations of a four-wheel steering apparatus according to an embodiment of the present invention. 4 is a block diagram briefly showing an apparatus for correcting neutral position of a four-wheel steering apparatus according to the present invention.

4, the apparatus for neutral position correction of a four-wheel steering apparatus according to the present invention mainly includes a front wheel steering actuator 100, a rear wheel steering actuator 200, and an electronic control unit 300. As shown in FIG. The four-wheel steering apparatus is provided with a front wheel steering actuator 100 and a rear wheel steering actuator 200 that steer the front wheel and the rear wheel, respectively, since the four-wheel steering apparatus must be configured to independently steer the front wheel and the rear wheel. The electronic control unit 300 functions to control the operations of the front wheel actuator 100 and the rear wheel steering actuator 200. [ The electronic control unit 300 drives the front wheel steering actuator 100 and the rear wheel steering actuator 200 in consideration of the steering intent of the user and the driving situation of the vehicle.

Hereinafter, a method for correcting a neutral position of a four-wheel steering apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3, based on the description of the four-wheel steering apparatus according to the present invention. FIG. 1 is a flow chart illustrating a method of correcting a neutral position of a four-wheel steering apparatus according to an embodiment of the present invention in a time-series manner. FIG. 2 is a more detailed sub- FIG. 3 is a conceptual diagram for explaining the details of calculating the correction angle in the neutral position correction method of the four-wheel steering apparatus according to the embodiment of FIG.

As shown in FIG. 1, the neutral position correction method of a four-wheel steering apparatus according to an embodiment of the present invention includes a first movement locus 600 and a second locus locus 600, (S100) of acquiring two-movement trajectory information. The first movement locus 600 is information obtained by the sensor 400 mounted on the vehicle and performs a function of detecting the behavior of the vehicle. Examples of such sensors include a steering angle sensor, an optical sensor, a wheel speed sensor, And an acceleration sensor. In particular, the steering angle sensor is a sensor for detecting the steering angle of the vehicle from the neutral position. By using the steering angle sensor and the wheel speed sensor or the vehicle speed sensor, it is possible to calculate the moving direction and distance of the vehicle intended by the driver. The second movement locus 700 is information obtained by a GPS receiver mounted on the vehicle, and is a locus including an actual movement direction and a movement distance of the vehicle irrespective of a user's intention to steer.

After the first step S100, the electronic control unit 300 determines the stroke between the front wheel steering actuator 100 and the rear wheel steering actuator 200 of the vehicle based on the first movement trajectory 600 and the second movement trajectory 700 A second step S200 of correcting the difference is performed. When there is a stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 in the four-wheel steering apparatus, the control precision at the time of turning of the vehicle is lowered, thereby deteriorating the vehicle adjustability and driving convenience of the driver It is preferable to reduce the stroke difference between the both actuators 100 and 200. To this end, the neutral position correcting method of the four-wheel steering apparatus according to an embodiment of the present invention includes a sensor 400 for detecting the behavior of the vehicle, Stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 by using the first movement locus 600 and the second movement locus 700 obtained from the GPS receiver 500 and the GPS receiver 500, .

Hereinafter, a method for correcting the neutral position of the four-wheel steering apparatus according to an embodiment of the present invention will be described in more detail with reference to FIG. As shown in FIG. 2, the neutral position correcting method of a four-wheel steering apparatus according to an embodiment of the present invention includes a first step (S110) of determining whether a steering wheel is in a neutral state, In step S120, it is determined whether the user has moved or not. This is because it is necessary to secure the moving distance and the moving time of the vehicle for forming the first locus 600 and the second locus 700 in accordance with the straight running state of the vehicle in the state where the handle is in the neutral position. Then, the electronic control unit 300 obtains the first trajectory 600 and the second trajectory 700 of the vehicle while the vehicle is traveling at a preset distance or a predetermined time while the steering wheel is set at the neutral position (S130).

In the second step S200, the electronic control unit 300 controls the first movement locus 600 and the second locus locus 700, (Step S210). 3, the deviation value a between the first movement locus 600 and the second locus locus 700 and the movement distance of the vehicle (i.e., the distance between the first movement locus 600 and the second locus locus 700) are calculated based on the comparison result in the 2-1st step S210 (step S230) of calculating the correction angle c on the basis of the calculated deviation value a and the moving distance b of the vehicle do. Step S240 of correcting the stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 of the vehicle finally based on the correction angle c calculated in the step 2-3 (S230) . The matching of the stroke correction value between the correction angle c and both the steering actuators 100 and 200 can be realized by a table stored in the electronic control unit 300 in advance and can also be converted by a predetermined formula will be.

Through the above process, the stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 in the four-wheel drive steering system can be easily self-corrected, thereby facilitating the driver's vehicle adjustability and driving convenience .

Hereinafter, an apparatus for correcting a neutral position of a four-wheel steering apparatus according to another embodiment of the present invention will be described with reference to FIG. 4, and redundant description of the method for correcting a neutral position of a four- . 4 is a block diagram briefly showing an apparatus for correcting neutral position of a four-wheel steering apparatus according to another embodiment of the present invention.

4, an apparatus for neutral position correction of a four-wheel steering apparatus according to another embodiment of the present invention includes a front wheel steering actuator 100, a rear wheel steering actuator 200, an electronic control unit 300, a sensor 400, And a GPS receiver (500). The sensor 400 performs a function of detecting the behavior of the vehicle, and is preferably at least one of a steering angle sensor, an optical sensor, a wheel speed sensor, and a lateral acceleration sensor. The GPS receiver 500 performs a function of receiving a GPS signal including movement information of the vehicle.

In particular, the apparatus for neutral position correction of a four-wheel steering apparatus according to another embodiment of the present invention is characterized in that the electronic control unit 300 includes a front wheel steering actuator (not shown) based on information transmitted from the sensor 400 and the GPS receiver 500 100 and the rear-wheel steering actuator 200 are corrected. Specifically, the electronic control unit 300 transmits the first movement locus 600 and the second locus locus 700 to the sensor 400 and the GPS receiver 500 in accordance with the running of the vehicle at the time of neutral setting of the steering wheel. Lt; / RTI > The electronic control unit 300 also corrects the stroke difference of the front wheel steering actuator 100 and the rear wheel steering actuator 200 based on the obtained first movement locus 600 and the second locus locus 700. [ Furthermore, the electronic control unit 300 also determines whether the steering wheel is neutral or not and determines whether the vehicle has moved beyond a predetermined distance.

On the other hand, the contents of the electronic control unit 300 correcting the stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 on the basis of the first movement locus 600 and the second locus locus 700 are specifically As follows. The electronic control unit 300 compares the first movement locus 600 and the second locus locus 700 and calculates a deviation value between the first locus locus 600 and the second locus locus 700 (a) and the moving distance (b) of the vehicle. After calculating the correction angle c based on the deviation value a and the moving distance b of the vehicle, the vehicle front-wheel steering actuator 100 and the rear-wheel steering actuator 200).

The embodiments and the accompanying drawings described in the present specification are merely illustrative of some of the technical ideas included in the present invention. Therefore, it is to be understood that the embodiments disclosed herein are not intended to limit the scope of the present invention but to limit the scope of the present invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. It should be interpreted.

100: front wheel steering actuator
200: rear wheel steering actuator
300: Electronic control unit
400: sensor
500: GPS receiver

Claims (9)

A first step (S100) in which the electronic control unit (300) acquires a first movement locus (600) and a second locus locus (700) in accordance with the running of the vehicle at the time of neutral setting of the handle; And
In which the electronic control unit 300 corrects the stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 of the vehicle based on the first movement locus 600 and the second movement locus 700, Step S200;
Lt; / RTI >
The first movement locus 600 is obtained by a sensor 400 mounted on a vehicle,
The second movement locus (700) is obtained by a GPS receiver (500) mounted on a vehicle.
The method according to claim 1,
The sensor (400) is at least one of a steering angle sensor, an optical sensor, a wheel speed sensor and a lateral acceleration sensor.
2. The method of claim 1, wherein the first step (SlOO)
A first step (S110) of determining whether the handle is neutral; And
(S120) of determining whether the vehicle has moved a predetermined distance or more;
Wherein the neutral position correcting means corrects the neutral position of the four-wheel steering apparatus.
The method according to claim 1, wherein the second step (S200)
A second step (S210) in which the electronic control unit 300 compares the first movement locus 600 and the second locus locus 700;
The electronic control unit 300 calculates the deviation value a between the first moving trajectory 600 and the second moving trajectory 700 and the moving distance b of the vehicle based on the comparison result, Step S220;
(S230) of the electronic control unit 300 calculating the correction angle c based on the deviation value a and the moving distance b of the vehicle; And
Step S240 of the electronic control unit 300 correcting the stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 of the vehicle based on the correction angle c;
Wherein the neutral position correcting means corrects the neutral position of the four-wheel steering apparatus.
A front wheel steering actuator (100) for steering a front wheel of a vehicle;
A rear wheel steering actuator 200 for steering the rear wheels of the vehicle;
An electronic control unit (300) for controlling the front wheel steering actuator (100) and the rear wheel steering actuator (200);
A sensor 400 for detecting the behavior of the vehicle; And
A GPS receiver 500 for receiving a GPS signal including movement information of the vehicle;
Lt; / RTI >
The electronic control unit 300 corrects the stroke difference between the front wheel steering actuator 100 and the rear wheel steering actuator 200 based on the information transmitted from the sensor 400 and the GPS receiver 500 The neutral position correction device of the four-wheel steering apparatus.
6. The method of claim 5,
The electronic control unit 300 transmits the first movement locus 600 and the second locus locus 700 to the sensor 400 and the GPS receiver 500 in accordance with the running of the vehicle at the time of neutral setting of the steering wheel. Lt; / RTI >
Wherein the stroke difference between the front wheel steering actuator (100) and the rear wheel steering actuator (200) is corrected based on the first movement locus (600) and the second locus locus (700).
The method according to claim 6,
Wherein the electronic control unit (300) determines whether or not the steering wheel is in a neutral state, and determines whether the vehicle has moved a predetermined distance or more.
7. The electronic control unit (300) according to claim 6, wherein the electronic control unit (300)
Comparing the first moving trajectory (600) and the second moving trajectory (700)
Calculates a deviation value (a) between the first movement locus (600) and the second locus locus (700) and a movement distance (b) of the vehicle based on the comparison result,
Calculates a correction angle (c) based on the deviation value (a) and the moving distance (b) of the vehicle,
Correcting the stroke difference between the front wheel steering actuator (100) and the rear wheel steering actuator (200) of the vehicle based on the correction angle (c).
6. The method of claim 5,
The sensor (400) is at least one of a steering angle sensor, an optical sensor, a wheel speed sensor and a lateral acceleration sensor.

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