KR101187040B1 - Apparatus for controlling cooperation of vehicle at dissymmetry friction road surface and control method therefor - Google Patents

Abstract

The present invention relates to a cooperative control apparatus for a vehicle and a control method thereof, which are capable of safely maintaining a straight motion of a vehicle without steering of a driver when the vehicle is braked on an asymmetric friction road surface.

To this end, the present invention determines whether or not the asymmetric friction road surface using the wheel speed received from the wheel speed sensor during braking, and overrides by reflecting the first and second solenoid valve information of the anti-lock brake system in the case of the asymmetric friction road surface A vehicle attitude control device that calculates an override angle and provides the calculated override angle or override angle threshold; And an active front wheel steering device for controlling steering in accordance with an override angle or an override angle threshold provided from the vehicle attitude control device.

Asymmetrical friction road, coordination, active front wheel steering, electronic control, anti-lock brake system, override angle

Description

Cooperative control device for vehicle on asymmetrical friction road and its control method {APPARATUS FOR CONTROLLING COOPERATION OF VEHICLE AT DISSYMMETRY FRICTION ROAD SURFACE AND CONTROL METHOD THEREFOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle cooperative control apparatus and a control method thereof, and more particularly, to a vehicle cooperative control apparatus and a control method thereof, which enable a vehicle to safely maintain a straight motion without steering by a driver during braking on an asymmetric friction road surface. .

When braking on a road with asymmetric friction, the braking force is different according to the road friction and the vehicle is pulled toward the road. In order to prevent the vehicle from tipping, the existing cooperative control is controlled only by the delta yaw, so that the yaw motion of the vehicle is large and the left and right yaw motions are also large.

In addition, an unbalance of the control amount occurs depending on how the driver presses the brake pressure. In particular, as the braking force of the vehicle is greatly generated during sudden braking and the delta yaw value is largely applied, the steer control amount of the vehicle is appropriately generated to allow the vehicle to move straight.However, when the brake is applied, the delta yaw value is relatively small to generate the steer. As the control volume is generated relatively small, there is a problem that the vehicle is directed to the high friction road surface.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooperative control apparatus for a vehicle and a method of controlling the same, which can improve the stability and braking force of the vehicle during braking on an asymmetric friction road surface through cooperative control between the vehicle attitude control apparatus and the active front wheel steering apparatus. .

In order to achieve the above object, the cooperative control apparatus for a vehicle according to the embodiment of the present invention determines whether it is an asymmetric friction road surface by using the wheel speed received from the wheel speed sensor during braking, and in the case of an asymmetric friction road surface, the anti-lock brake A vehicle attitude control device for calculating an override angle by reflecting first and second solenoid valve information of a system and providing the calculated override angle or override angle limit value; And an active front wheel steering device that controls steering in accordance with an override angle or an override angle threshold provided from the vehicle attitude control device.

In this embodiment, the vehicle attitude control device includes a receiving unit for receiving the wheel speed from the wheel speed sensor; A determination unit determining whether the current road surface is an asymmetric friction road surface according to the received wheel speed; A calculation unit for calculating an override angle to be provided to the active front wheel steering device in the case of an asymmetric friction road surface as a result of the determination of the determination unit; And a provision unit for providing an override angle or an override angle limit value to the active front wheel steering apparatus by comparing the calculated override angle with the override angle limit value.

Here, the calculation unit calculates the override angle through the delta yaw and PID control which is the difference between the yaw rate measured from the yaw rate sensor and the yaw rate calculated therein, and the first and second solenoid valves of the anti-lock brake system Combining the information to calculate a moving average for the combined value, calculate the valve angle through the moving average and PID control, and calculates the override angle reflecting the valve information by using the valve angle and the override angle It is done.

A control method of a vehicle cooperative control apparatus according to an embodiment of the present invention includes the steps of receiving a wheel speed from a wheel speed sensor; Determining whether the current road surface is an asymmetric friction road surface according to the received wheel speed; Calculating an override angle to be provided to the active front wheel steering device in the case of the asymmetric friction road surface; And providing an override angle or override angle limit to the active front wheel steering apparatus by comparing the calculated override angle with the override angle limit. The override angle is a supplementary steering angle required for active steering, and is a signal for arbitrarily requesting a steering angle from the AFS 30.

Here, the calculating step is to calculate the override angle through the delta yaw and PID control, which is the difference between the yaw rate measured from the yaw rate sensor and the internally calculated yaw rate, and the first and first solenoid valves of the anti-lock brake system The combination of the information is calculated to calculate a moving average for the combined value, the valve angle is calculated through the moving average and PID control, and the override angle reflecting valve information is calculated using the valve angle and the override angle. At this time, PID control is a combination of proportional control, integral control, and derivative control, and can be configured as a controller because it is a control algorithm. Specifically, the PID control is expressed as in Equation 1 below, a proportional action (P action) that produces a correction amount proportional to the current deviation (e), and a correction amount proportional to a cumulative value of the previous deviations. It is a combination of an integral action (I action) that produces a signal and a derivative action (D action) that produces a correction amount proportional to the magnitude of the tendency of whether the deviation (e) is increasing or decreasing.

Here, y is a detection amount, Kp is a proportional coefficient, e is a deviation (target value-effective value), Ti is an integration time, and T _D is a derivative time.

Further, the providing step may further include determining whether the vehicle speed of the vehicle is smaller than the predetermined vehicle speed, and if the vehicle speed of the vehicle is smaller than the constant vehicle speed, the valve information calculated by the valve angle and the override angle is reflected. The override angle or override angle limit value is provided to the active front wheel steering apparatus, and if the vehicle speed of the vehicle is greater than a predetermined vehicle speed, the override angle or override angle threshold calculated through the delta yaw and PID control is provided to the active front wheel steering apparatus. .

According to the embodiment of the present invention, the braking on the asymmetrical friction road surface has the effect of maintaining a constant straight running of the vehicle without steering of the driver.

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

FIG. 1 is a block diagram for explaining a cooperative control apparatus for a vehicle according to an exemplary embodiment of the present invention, and FIG. 2 is a block diagram for explaining the electronic control braking apparatus shown in FIG.

Referring to FIG. 1, a cooperative control apparatus for a vehicle according to an exemplary embodiment of the present invention includes a vehicle attitude control apparatus (ESC) 20 and an active front wheel steering apparatus (AFS). Steering, hereinafter referred to as 'AFS').

Here, the ESC 20 receives vehicle information from the wheel speed sensor 11, the yaw rate sensor 12, and the lateral acceleration sensor 13, and hydraulically controls each solenoid valve, for example, the first and second solenoid valves. It drives to the drive part 14.

The AFS 30 receives the steering angle from the steering angle sensor 11 and controls the steering driver 14 according to the received steering angle. In particular, the AFS 30 controls steering in accordance with an override angle or a preset override angle threshold provided from the ESC 20.

The ABS 5 in the ESC 20 is a system that receives the wheel speeds from the four wheel speed sensors 11 and generates pressure so that each wheel maintains an optimum slip so that the wheels do not lock and generate braking force.

In this embodiment, the ESC 20 determines whether the current road surface is an asymmetric friction road surface (hereinafter referred to as 'split mu') based on the wheel speeds received from the four wheel speed sensors 11, and If the road surface is split mu, the override angle is calculated through delta yaw and control, for example, PID control, that is the difference between the yaw rate measured from the yaw rate sensor 12 and the yaw rate calculated inside the ESC 20. At this time, when the vehicle speed of the vehicle is greater than the predetermined vehicle speed, the override angle or the preset override angle threshold calculated through the delta yaw and PID control is provided to the AFS 30.

When the vehicle speed of the vehicle is smaller than the predetermined vehicle speed, the ESC 20 may provide information on the first solenoid valve (hereinafter referred to as 'NO valve') and the second solenoid valve (hereinafter referred to as an 'NC valve') of the ABS 5. Combine information. At this time, the NO valve is a normally open solenoid valve, and maintains a normally open state, the NC valve is a normally closed solenoid valve, and maintains a normally closed state.

The ESC 20 calculates an override angle reflecting the NO and NC valve information of the ABS 5 and provides the override AFS 30 with an override angle or a preset override angle reflecting the calculated valve information.

That is, the ESC 20 provides the override angle or override angle limit to the AFS 30 by comparing the override angle and the override angle threshold determined through the delta yaw and PID control when the vehicle speed is greater than the constant vehicle speed, but the vehicle speed is constant. If it is smaller than the vehicle speed, the override angle reflecting the NO and NC valve information of the ABS 5 is calculated and the calculated override angle or override angle threshold is provided to the AFS 30. Accordingly, the AFS 30 may control steering in accordance with the override angle or the override angle limit provided from the ESC 20, thereby maintaining the straight motion without braking the driver during braking in the split mu, thereby increasing the stability of the vehicle.

2, the ESC 20 includes a receiver 21, a determiner 22, a calculator 23, and a provider 24.

The receiver 21 receives vehicle information measured from the four wheel speed sensors 11, the yaw rate sensor 12, and the lateral acceleration sensor 13 during braking.

The determination unit 22 determines whether the current road surface is split mu based on the wheel speed received through the reception unit 21. In addition, the determination unit 22 determines whether the vehicle speed calculated by using the wheel speed received by the reception unit 21 is smaller than a predetermined constant vehicle speed.

The calculation unit 23 calculates the delta yaw by subtracting the yaw rate received by the receiver 21 to the yaw rate calculated in the ESC 20.

In particular, the calculation unit 23 calculates the override angle through the calculated delta yaw and PID control. In this case, the calculated override angle may be output to the AFS 30 when the vehicle speed is greater than the predetermined vehicle speed.

In addition, the calculation unit 23 calculates a moving average for the combined value by combining the NO valve information and the NC valve information through the following equation (2).

Here, X means the time axis, n means the position of the time axis, and a means the number of sampling data.

That is, as shown in the graph shown in FIG. 4, the calculation unit 23 calculates the moving average of the combined values by combining the respective valve signals through Equation 2 described above.

In addition, the calculator 23 calculates the valve angle through the calculated moving average and PID control. In addition, the calculation unit 23 calculates the override angle reflecting the valve information by adding the calculated valve angle and the previously calculated override angle.

Next, the providing unit 24 compares the calculated override angle with the override angle and the override angle limit value, and if the override angle with the valve information is less than the override angle limit value, outputs the override angle with the valve information reflected to the AFS 30, and the valve If the override angle reflecting the information is larger than the override angle limit, the override angle limit value is output to the AFS 30. At this time, when the vehicle speed is greater than the predetermined vehicle speed, the providing unit 24 compares the override angle calculated by the delta yaw and the PID control with the preset override angle threshold and provides the override angle or the override angle threshold to the AFS 30. When the vehicle speed is smaller than the predetermined vehicle speed, the override angle reflecting the valve information and the preset override angle limit value are compared to provide the override angle or override angle limit reflecting the valve information to the AFS 30.

The AFS 30 and the ESC 20 may be connected through a communication means (not shown) such as a can to receive information.

The AFS 30 includes a steering handle (not shown) coupled with a steering column, first and second steering angle sensors 31 and 32, a steering driver 33, an active controller (not shown), and the like. In addition, the front wheel steering angle control can be performed by receiving the state information of the vehicle from the active controller.

In particular, the AFS 30 controls steering in accordance with the override angle or override angle threshold provided from the ESC 20.

In this way, it is possible to safely carry out a straight motion during braking on an asymmetric friction road surface.

Referring to the control method of the vehicle cooperative control device having such a configuration as follows.

3 is a flowchart illustrating a control method of a vehicle cooperative control apparatus according to an embodiment of the present invention.

Referring to FIG. 3, in the control method of the cooperative control apparatus for a vehicle according to the present invention, when the cooperative control of the AFS 30 and the ESC 20 is performed, the wheel angle of the vehicle is steered without the driver's steering when braking in the split mu. The attitude of the vehicle can be controlled.

The receiver 21 of the ESC 20 receives the wheel speed from the wheel speed sensor 11 during braking (S101).

Next, the determination unit 22 of the ESC 20 determines whether the current road surface is split mu using the received wheel speed (S103).

As a result of the determination in step S103, when it is not the split mu, the ESC 20 causes the steering to be controlled according to the steering operation (S104).

As a result of the determination in step S103, in the case of the split mu, the calculation unit 23 of the ESC 20 uses the yaw rate measured by the yaw rate sensor 12 and the yaw rate calculated inside the ESC 20. (Delta yaw) is calculated (S105).

Next, the calculation unit 23 calculates the override angle through the calculated delta yaw and PID control (S107). Here, the override angle is a signal for arbitrarily requesting a steering angle from the AFS 30.

Next, the determination unit 22 determines whether the vehicle speed is smaller than the predetermined vehicle speed (S109). At this time, as the vehicle travels at a low speed, the delta is gradually decreased. When the vehicle speed is smaller than the predetermined constant speed in order to reinforce the vehicle, the AFS 30 is reflected by reflecting the NO valve information and the NC valve information of the ABS 5 through the following process. Calculate the override angle to be given by.

If the vehicle speed is greater than the predetermined vehicle speed in step S109, the process moves to step S119, which will be described later, to determine whether the calculated override angle is less than or equal to the override angle limit.

As a result of the determination in step S109, when the vehicle speed is smaller than the predetermined vehicle speed, the receiver 21 combines the NO valve information and the NC valve information of the ABS 5 (S111). For example, as shown in Table 1 below, when the NO valve information is '0' and the NC valve information is '1', the combination is '1', the NO valve information is '1', and the NC valve information is '0'. Is combined with '-1'. If NO valve information is '1' and NC valve information is '1', it is combined with '0'.

NO NC Combination rise 0 One One Dump One 0 -One Hold One One 0

Next, the calculation unit 23 calculates the moving average for the combined value of the combined NO valve information and NC valve information by using Equation 2 described above (S113).

Next, the calculation unit 23 calculates the valve angle through the calculated moving average and PID control (S115). For example, the calculator 23 calculates the valve angle by multiplying the moving average by the PID gain.

Next, the calculation unit 23 calculates an override angle in which the valve angle is reflected using the valve angle and the override angle calculated in step S107 (S117). That is, the calculator 23 calculates the override angle in which the valve angle is reflected by adding the valve angle and the override angle.

Next, the providing unit 24 of the ESC 20 determines whether or not the override angle in which the valve angle is reflected or the override angle calculated in the step S107 is less than or equal to the override angle limit (S119).

As a result of the determination in step S119, when the override angle in which the valve angle is reflected or the override angle calculated in the step S107 is less than or equal to the override angle threshold, the providing unit 24 determines the override angle in which the valve angle is reflected or the override angle calculated in the step S107. Output to AFS 30 (S123). At this time, the AFS 30 controls steering according to the override angle output from the ESC 20.

As a result of the determination in step S119, when the override angle reflected by the valve angle or the override angle calculated in the step S107 is larger than the override angle limit value, the ESC 30 outputs the override angle limit value to the AFS 30 (S122). At this time, the AFS 30 controls steering according to the override angle threshold output from the ESC 20.

Accordingly, the vehicle attitude may be controlled by using the ABS valve information of the vehicle while performing cooperative control between the ESC 20 and the AFS 30 during braking. In particular, the posture of the vehicle can be stably controlled as compared to the control of the posture of the vehicle using only the delta.

The invention being thus described, it will be obvious that the same way may be varied in many ways. Such modifications are intended to be within the spirit and scope of the invention as defined by the appended claims.

1 is a block diagram illustrating a vehicle cooperative control apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating the vehicle attitude control apparatus shown in FIG. 1. FIG.

3 is an operation flowchart for explaining a control method of a vehicle cooperative control apparatus according to an embodiment of the present invention.

4 is a graph showing the valve signal of the ABS according to an embodiment of the present invention.

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

5: anti-lock brake system (ABS) 11: four wheel speed sensors

12: yaw rate sensor 13: lateral acceleration sensor

14: hydraulic drive unit 20: vehicle attitude control device (ESC)

30: active front wheel steering (AFS) 31: first steering angle sensor

32: second steering angle sensor 33: steering drive unit

Claims (6)

In braking, the wheel speed received from the wheel speed sensor is used to determine whether the road is an asymmetric friction road surface, and in the case of an asymmetric friction road surface, the override angle is reflected by reflecting the first and second solenoid valve information of the anti-lock brake system. A vehicle attitude control device that calculates and provides the calculated override angle or override angle threshold; And And an active front wheel steering device that controls steering in accordance with an override angle or an override angle threshold provided from the vehicle attitude control device. The method according to claim 1, The vehicle attitude control device includes a receiver for receiving a wheel speed from the wheel speed sensor; A determination unit determining whether the current road surface is an asymmetric friction road surface according to the received wheel speed; A calculation unit for calculating an override angle to be provided to the active front wheel steering device in the case of an asymmetric friction road surface as a result of the determination of the determination unit; And And providing the override angle or the override angle limit value to the active front wheel steering apparatus by comparing the calculated override angle with the override angle limit value. The method according to claim 2, The calculation unit calculates the override angle through the delta yaw and PID control, which is the difference between the yaw rate measured from the yaw rate sensor and the yaw rate calculated therein, Calculate a moving average of the combined values by combining the first and second solenoid valve information of the anti-lock brake system, The valve angle is calculated through the moving average and PID control, And an override angle in which valve information is reflected using the valve angle and the override angle. Receiving the wheel speed from the wheel speed sensor when braking; Determining whether the current road surface is an asymmetric friction road surface according to the received wheel speed; Calculating an override angle using first and second solenoid valve information of the antilock brake system in the case of an asymmetric friction road surface; Providing an override angle or override angle limit to an active front wheel steering apparatus by comparing the calculated override angle with an override angle threshold; And And controlling steering in accordance with the provided override angle or the override angle threshold. The method of claim 4, The calculating step is to calculate the override angle through the delta yaw and PID control, which is the difference between the yaw rate measured from the yaw rate sensor and the internally calculated yaw rate, Calculate a moving average of the combined values by combining the first and second solenoid valve information of the anti-lock brake system, The valve angle is calculated through the moving average and PID control, And controlling the override angle reflecting the valve information using the valve angle and the override angle. The method of claim 5, The providing step Determining whether the vehicle speed of the vehicle is smaller than a predetermined vehicle speed, If the vehicle speed of the vehicle is less than a predetermined vehicle speed, the override angle or override angle limit value reflecting the valve information calculated by the valve angle and the override angle is provided to the active front wheel steering apparatus, And if the vehicle speed of the vehicle is greater than a predetermined vehicle speed, provide an override angle or an override angle threshold calculated through the delta yaw and PID control to the active front wheel steering apparatus.

Images