KR101279162B1 - Method for controlling steering for cars - Google Patents

Abstract

The present invention relates to a steering control method for a vehicle that executes an appropriate countersteer corresponding to a slip angle during sharp turning, the method comprising calculating a vehicle's traveling direction angle, and adjusting the slip angle of the vehicle at yaw rate, lateral acceleration, and vehicle speed. Calculating, when the slip angle of the vehicle is calculated, measuring the wheel angle and correcting the wheel angle according to the size of the slip angle with respect to the wheel angle; and when the wheel angle is corrected, steering the wheel angle according to the corrected wheel angle. Characterized in that it comprises a step.

Vehicle, EPS, ESP, VGR, Slip Angle

Description

{Method for controlling steering for cars}

1 is a view showing a driving state of a vehicle during a conventional steep steering.

2 is a block diagram of a steering control apparatus for a vehicle according to an exemplary embodiment of the present invention.

3 is a flow chart of a vehicle steering control method according to an embodiment of the present invention.

4 is a view showing a vehicle traveling direction angle according to an embodiment of the present invention.

5 is a view showing a driving state of the vehicle at the time of rapid steering according to the embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: vehicle attitude control system

11: yaw rate sensor

12: Lateral Acceleration Sensor

13: speed sensor

14: angle sensor

15: slip angle calculator

16: micom

20: electronically controlled steering system

30: variable gear ratio steering system

The present invention relates to a vehicle, and more particularly, to a steering control method of a vehicle that executes an appropriate counter steer corresponding to a slip angle during sharp turning.

To avoid a lane change or accident in an emergency situation while driving a vehicle, the average driver makes excessive manipulations that are difficult to cope with.

In particular, a driver who does not have a lot of training tends to sharply turn the steering wheel because the vehicle's direction slips instead of driving in the direction of the steering wheel in a sudden S-shaped course or a sharp turn.

That is, as shown in FIG. 1, since the steering wheel is operated excessively on a sharp turning road, only a slip angle becomes larger between the tire driving direction and the vehicle traveling direction, and after a while, the steering angle is too sharply rotated in the opposite direction. This causes the vehicle to keep shaking and not to pose, resulting in a sudden yaw, which eventually leads to an accident.

Therefore, a counter steer operation must be performed quickly and accurately to adjust the direction of the wheel in the traveling direction of the vehicle so that the vehicle can be positioned while reducing the slip angle of the vehicle as much as possible.

Accordingly, an electronic power steering system (EPS) has recently been proposed to assist automatic counter steer.

The electronically controlled steering system uses the vehicle speed sensor, steering angle sensor, and throttle position sensor to control the vehicle's steering force to provide the driver with proper steering conditions.

However, since the electronically controlled steering system automatically adjusts the steering wheel, there may be a great risk when the driver steers against the steering wheel that is automatically adjusted.

Therefore, there is a need to actively control the wheels of the vehicle, not the steering wheel, regardless of the driver's driving technology during rapid steering.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and provides a vehicle attitude control method for executing a counter steer according to a slip angle calculated through yaw rate, lateral acceleration, and speed.

Another object of the present invention is to automatically execute the counter steer according to the slip angle to prevent the sudden steer of the steer by the driver in advance and to reduce the risk of accidents that may occur during sharp turns.

The configuration of the present invention, which is invented to achieve the above-described object, is as follows. The steering control method of the vehicle of the present invention comprises the steps of calculating the heading direction angle of the vehicle, calculating the slip angle of the vehicle at the yaw rate, the lateral acceleration, and the vehicle speed, and when the slip angle of the vehicle is calculated, the wheel angle is calculated. Measuring and correcting the wheel angle according to the size of the slip angle with respect to the wheel angle; and steering the wheel angle according to the corrected wheel angle when the wheel angle is corrected. .

The slip angle is the following equation

Β (t) represents the slip angle at time t, β ₀ is the initial value of the slip angle, V _X is the traveling direction speed of the vehicle, and V _Y is the lateral speed of the vehicle. , Ψ is the yaw rate.

The corrected wheel angle is calculated by subtracting the slip angle from the measured wheel angle.

Each of the steps may be repeated until the slip angle becomes zero.

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

2 is a block diagram of a steering control apparatus for a vehicle according to an exemplary embodiment of the present invention.

As shown in FIG. 2, a vehicle steering control apparatus according to an exemplary embodiment of the present invention includes a vehicle stability control system (Electronic stability program) 10, an electronically controlled steering system 20, and a variable gear ratio steering system. ratio 30).

The vehicle attitude control system 10 controls the wheels appropriately in a dangerous situation in which a tire reaches a contact limit while driving, so that the driver can move the vehicle in a desired direction. The yaw rate sensor 11 and the lateral acceleration The sensor 12, the speed sensor 13, the angle sensor 14, the slip angle calculating part 15, and the microcomputer 16 are provided.

First, the yaw rate sensor 11 detects the yaw moment of the vehicle determined by the moments of the four wheels, and the lateral acceleration sensor 12 detects the turning degree of the vehicle, that is, the lateral acceleration. The sensor 13 detects the speed of the vehicle, and the angle sensor 14 detects the wheel angle of the steering wheel.

The microcomputer 16 receives sensing signals from the yaw rate sensor 11, the lateral acceleration sensor 12, the speed sensor 13, and the angle sensor 14, and the movement direction of the vehicle and the traveling direction angle ( calculate a heading angle).

In addition, the calculated yaw rate, the lateral speed of the vehicle, and the vehicle traveling direction speed are output to the slip angle calculator 15, and a wheel angle is obtained by using the slip angle input from the slip angle calculator 15. ), And outputs a steering control signal according to the corrected wheel angle to the electronically controlled steering system 20.

The corrected wheel angle depends on the size of the slip angle, which is calculated by subtracting the above slip angle from the wheel angle measured by the angle sensor 14.

Meanwhile, the slip angle calculator 15 calculates a slip angle using the yaw rate, the lateral acceleration, and the vehicle speed, and outputs the calculated slip angle to the microcomputer 16.

The slip angle calculator 15 calculates a slip angle through Equation 1 below.

Here, β is a slip angle, β (t) represents a slip angle at time t, and β ₀ is an initial value of the slip angle. In addition, V _X is the traveling direction speed of the vehicle, V _Y is the lateral speed of the vehicle, and Ψ is the yaw rate.

That is, the yaw rate calculated according to the sensing signal sensed by the yaw rate sensor 11, the lateral acceleration sensor 12, and the speed sensor 13, the traveling direction speed of the vehicle, and the transverse speed of the vehicle are described. The slip angle is calculated by substituting Equation (1).

On the other hand, the electronically controlled steering system 20 provides a proper steering force to the driver, and when a steering control signal is input from the microcomputer 16, the wheel corrected by controlling the variable gear ratio steering system 30 according to the steering control signal. Allow the vehicle to proceed at an angle.

Finally, the variable gear ratio steering system 30 steers the wheel according to the control signal input from the electronically controlled steering system 20 so that the vehicle proceeds in the direction of the corrected wheel angle even if the user excessively manipulates the steering wheel.

Hereinafter, an operation process of the vehicle attitude control device will be described in detail with reference to FIGS. 3 to 5.

3 is a flow chart of a vehicle steering control method according to an embodiment of the present invention, Figure 4 is a view showing the vehicle traveling direction angle according to an embodiment of the present invention, Figure 5 is a rapid steering according to the embodiment of the present invention A diagram illustrating a driving state of a city vehicle.

In the steering control method of the vehicle according to the exemplary embodiment of the present invention, when sensing signals are input from the yaw rate sensor 11, the lateral acceleration sensor 12, the speed sensor 13, and the angle sensor 14, respectively, the microcomputer ( 16) calculates the direction of movement of the vehicle and the direction of travel of the vehicle using the sensing signal (S10 to S20).

In addition, the yaw rate, the lateral speed of the vehicle, and the vehicle traveling direction speed are output to the slip angle calculator 15, and the slip angle calculator 15 outputs the yaw rate, the lateral speed of the vehicle, and the vehicle travel direction. The slip angle is calculated using the speed (S30).

When the movement direction of the vehicle and the traveling direction angle of the vehicle are calculated as described above, the slip angle is calculated (S30), and the slip angle is the yaw rate, the traveling direction speed of the vehicle, and the vehicle as shown in Equation 1 above. Calculated through the lateral velocity.

The slip angle calculator 15 outputs the calculated slip angle to the microcomputer 16, and the microcomputer 16 calculates the corrected wheel angle through the slip angle (S40).

The corrected wheel angle is calculated by subtracting the above-mentioned slip angle from the actual wheel angle measured by the angle sensor 14.

As such, when the corrected wheel angle is calculated, the microcomputer 15 outputs a steering control signal to the electronically controlled steering system 20 according to the corrected wheel angle, and the electronically controlled steering system 20 outputs the steering control signal. By controlling the variable gear ratio steering system 30 in accordance with, the counter steer, that is, steering (S50) by the corrected wheel angle.

In addition, the wheel is steered by the corrected wheel angle, and the slip angle is determined to be 0 °. The slip angle of 0 ° is determined by the wheel angle measured by the angle sensor 14 and the actual vehicle. It is a case where the vehicle progresses only by the driver's operation without the slip angle occurring without the slip angle occurring, and the advancing direction angles coinciding.

Therefore, the above process is repeated until the slip angle is 0 degrees.

Referring to FIG. 4, the driver operates the steering wheel to determine the direction of the wheel as the wheel angle in the direction of the right arrow.

Here, the corrected wheel angle is obtained by subtracting the slip angle from the wheel angle measured by the angle sensor 14.

Accordingly, the wheel angle is obtained by subtracting the slip angle from the measured wheel angle (the direction of the arrow located at the far left).

That is, the wheel angle in the direction of the arrow located in the middle of the three arrows becomes the corrected wheel angle, and the direction in which the actual vehicle proceeds also proceeds in the direction (center arrow direction) according to the corrected wheel angle.

Therefore, as shown in FIG. 5, even if the user excessively manipulates the steering wheel, the vehicle proceeds by the wheel angle corrected by the slip angle until the slip angle becomes 0 °, so that the driver does not rotate significantly. Can make stable operation.

The present invention is not limited to the above-described embodiments and can be carried out in various modifications within the scope of the technical idea of the present invention.

According to the present invention configured as described above, the countersteer is automatically executed according to the slip angle calculated through the yaw rate, the lateral acceleration, and the speed, thereby preventing the steerier steered by the driver. This reduces the risk of accidents that may occur during sharp turns.

Claims (4)

Calculating a traveling direction angle of the vehicle; Calculating a slip angle of the vehicle at the yaw rate, the lateral acceleration, and the vehicle speed; When the slip angle of the vehicle is calculated, correcting the wheel angle by measuring a wheel angle so that the traveling angle of the vehicle coincides with the wheel angle according to the size of the slip angle with respect to the wheel angle; And Steering the wheel angle according to the corrected wheel angle when the wheel angle is corrected, The slip angle is the following equation

Β (t) represents the slip angle at time t, β ₀ is the initial value of the slip angle, V _X is the traveling direction speed of the vehicle, and V _Y is the lateral speed of the vehicle. , Ψ is yaw rate. delete 2. The method of claim 1, wherein the corrected wheel angle is calculated by subtracting the slip angle from the measured wheel angle. The method of claim 1, wherein the steps are repeated until the slip angle becomes zero.

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