KR0172637B1 - Active roll control device for a vehicle - Google Patents

Abstract

The present invention relates to an active roll control apparatus for a vehicle having a sensor unit, a hydraulic control valve unit, a rotary actuator, a control unit, and a hydraulic source for each of the front and rear wheels of the vehicle.

The sensor unit consists of three sensors: a vehicle speed sensor, a steering angle sensor, and a rotary actuator rotation angle sensor. The rotary actuator rotation angle sensor directly detects the roll angle of the vehicle, and the actuator supplies hydraulic oil from the proportional directional control valve. Receiving torque to generate a rotational movement, both ends of the actuator is attached to the stabilizer bar configured to move relative to each other in the opposite direction around the rotary actuator to control the roll shape of the vehicle is limited the maximum rotation angle.

The proportional directional control valve is a tandem center proportional directional control valve that determines the rotation direction and the rotation angle of the rotary actuator, and the hydraulic discharge amount of the pump when the operation of the control device is unnecessary, such as when the vehicle runs on a flat road. It is configured to bypass.

Description

Vehicle's active roll control

1 is an illustration of a conventional stabilizer bar.

2 is a view schematically showing that a conventional stabilizer bar is mounted on a vehicle.

3 is an exemplary view showing a configuration of a stabilizer bar equipped with a rotary actuator and a rotation displacement sensor according to the present invention.

Figure 4 is a block diagram schematically showing an active roll control apparatus according to the present invention.

5 is an exemplary view showing the use of a motor-driven hydraulic pump in the front and rear active roll control device of the present invention.

6 is an exemplary view showing the use of an engine-driven hydraulic pump in the front and rear active roll control device of the present invention.

7 is a cross-sectional view of an angle sensor-mounted hydraulic rotary actuator according to the present invention.

8 is a longitudinal sectional view of an angle sensor-mounted hydraulic rotary actuator according to the present invention.

9 is a block diagram showing a control scheme employed in the present invention.

* Explanation of symbols for main parts of the drawings

1: steering angle sensor 11: diagnostic device

2: vehicle speed sensor 12: vane

3: rotation displacement sensor 13: housing

4: hydraulic pump 14: relief valve

6: actuator 15: directional control valve

7: Stabilizer Bar 16: On / Off Valve

8: control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active roll control device for minimizing the change of attitude of a vehicle during steering and turning, and to optimize the movement characteristics of the vehicle. .

The present invention is to install a proportional directional control valve in the vehicle stabilizer device to continuously control the rotation angle of the rotary hydraulic actuator, thereby suppressing the roll phenomenon caused by the driving state to improve the ride comfort by making the vehicle as horizontal as possible, It aims to improve the attitude control, maneuverability and safety of the vehicle by continuously controlling the rotation angle of the rotary hydraulic actuator during turning, braking and steering.

Such a control device controls the traction of the tire when turning, the stiffness of the stabilizer can be changed according to the driving mode of the vehicle, and in the event of a failure of the control device, the control pressure must be maintained for smooth pressure fluctuation and constant stiffness. In addition, the pressure of the control device must be possible and easy to return to the original state.

In addition, compared with other high performance active suspension devices of the same purpose, the structure is simple, so that the volume and weight, and the energy consumption is low, it should not be limited to the application model.

As a roll stabilizer of a vehicle by a conventional stabilizer, a so-called passive stabilizer bar is known.

The stabilizer bar serves as a kind of torsion spring, an example of a conventional stabilizer bar is shown in FIG.

Transverse acceleration occurs due to centrifugal force when the vehicle is turning, which causes the vehicle to generate rotational moments around the center of gravity of the vehicle, tilting the vehicle in the direction of the lateral acceleration, and excessively heavy weight of the vehicle. It is transferred and slips occur in the tire, which weakens steering. In addition, when the pump passes through, the vehicle also has a low frequency of swelling.

In order to prevent such a phenomenon, the left and right knuckles of the front wheel and the rear wheel are connected to the stabilizer to compensate the torque due to the difference in the left and right heights with the torque corresponding to the angular displacement of the stabilizer bar.

However, the existing stabilizer has a fixed sensitivity and thus cannot cope with various sudden changes in driving conditions, and only passively responds to the external roll moment.

Therefore, increasing the stabilizer tends to reduce the roll phenomenon, but results in a very deteriorating ride. Conversely, reducing the stabilizer excessively increases the roll phenomenon, which greatly affects the driving safety of the vehicle. .

In Korean Patent Application No. 95-1704, an active roll control apparatus has been proposed to solve the problems of the related art.

However, the active roll control device operates only according to a pre-programmed response method, and thus does not actively respond to a change in the condition of the vehicle, and also has a problem in that the valve unit for adjusting the hydraulic actuator is relatively complicated.

Accordingly, in order to solve the conventional problems as described above, the active roll control apparatus of the vehicle of the present invention may be divided into a sensor unit, a front wheel valve unit, a front wheel actuator unit, a rear wheel valve unit, a rear wheel actuator unit and a control unit. .

The description of these units is as follows.

The sensor unit consists of three sensors: a vehicle speed sensor, a steering angle sensor, and a rotary actuator rotation angle sensor.

Vehicle speed sensors and steering angle sensors are mostly installed in commercial vehicles, and rotary actuator rotation angle sensors directly detect the roll angle of the vehicle in the form of potentiometers or encoders, which are used in other intelligent active systems. It has the advantage of being simpler and more structurally and functionally than the attitude detection device of the vehicle. Front wheel valve unit is composed of tandem center proportional directional valve and on / off valve.

The tandem center type proportional directional control valve determines the rotation direction and angle of rotation of the rotary actuator. The reason for using the tandem center type is the hydraulic discharge amount of the pump when the operation of the control device is unnecessary, such as when the vehicle is traveling on a flat road. To bypass all of them.

In addition, an on / off valve is arranged between both ports of the rotary actuator to open the opening when driving on a flat road, making the stabilizer almost zero (zero), and in case of malfunction such as system failure. Closely mechanically configured to achieve greater rigidity than conventional passive stabilizers.

The front wheel actuator receives hydraulic oil from the proportional directional control valve to generate torque and rotate. Stabilizer bars are attached to both ends of the actuator, and in order to control the roll phenomenon of the vehicle, stabilizer bars are designed to move relative to each other about the rotary actuator.

Rotary actuators are limited in a certain maximum rotational angle to mechanically set the critical roll angle of the vehicle.

The rear wheel valve unit has the same function or structure as the front wheel valve unit, and the rear rotary actuator is the same as that of the front wheel.

The control unit detects the information of the vehicle from the sensor and adjusts the current applied to the front and rear wheel hydraulic valve units to control the actuator operation for the desired roll control.

As the hydraulic source, a motor-driven hydraulic pump with a relief valve attached to the tank or an engine-driven hydraulic pump is used.

In the case of the motor-driven type, it saves energy by shutting off the power of the motor when it is not necessary, and in the case of the engine-driven type, it can save energy by the bypass function of the tandem center proportional directional control valve.

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

As shown in FIG. 3, the active roll control apparatus according to the present invention includes a rotary actuator 6 having a rotation displacement sensor (rotation angle sensor) 3 and two stabilizers mounted at both ends thereof.

An actuator according to an embodiment of the invention is shown in cross-sectional and longitudinal cross-sectional views, respectively, in FIGS. 7 and 8.

The actuator is provided with a housing 13, a rotor shaft 11, and a vane 12 mounted to the rotor shaft, one end of the rotor shaft being coupled to one stabilizer bar, and a housing 13 incorporating the rotor shaft and vanes. Another stabilizer bar is coupled to an end of the rotor shaft opposite to one end of the rotor shaft. One end of the rotor shaft is mounted with a relative angle of rotation 10, and is configured to rotate together with the vanes when the rotor shaft rotates.

When an unbalanced state such as a roll of the vehicle occurs while the vehicle is running, the housing 13 and the rotor shaft 11 rotate in opposite directions as shown by arrows A and B in FIGS. 7 and 8. The relative rotational angle sensor detects the relative rotational displacement between the one end of the housing and the one end of the rotor shaft, and sends the data to the electronic control unit 8 described later.

4 is a schematic diagram illustrating a hydraulic electronic control system of the present invention as shown in FIG. 4, and is attached to a steering angle sensor, a vehicle speed sensor 2, and a rotary actuator 6 for detecting an angle change of a steering wheel of a vehicle by a driver. The data sensed by each sensor 3 is input to the electronic control unit 8, which processes the input data and outputs a related signal to the diagnostic device 9 and the display device 10. In addition, the open / close command signal is transmitted to the hydraulic valve unit 5 connected to the hydraulic pump 4.

The operation relationship of the present invention will be described in more detail with reference to the circuit diagrams shown in FIGS. 5 and 6.

The hydraulic source preferably used in the present invention may be a motor driven type (figure 5) or an engine driven type (figure 6) as the tank-integrated hydraulic pump 4, to which the relief valve 14 is attached.

The oil discharged from the hydraulic pump is supplied to and discharged from the chambers of the hydraulic valve unit 5 and the rotary actuator 6 disposed corresponding to the front and rear wheels so as to apply a force to the stabilizer 7 connected to the rotary actuator. To control the motion of the vehicle. The highest operating input of the system is then set by the relief valve 14 attached to the pump.

The motion state of the vehicle is controlled by the proportional solenoids of the proportional direction control valves 15 and 15 by means of the detection signals of the rotary actuator rotation angle sensor 3 and the steering angle sensor 1 and the vehicle speed sensor 2. Optimally control posture, safety, and posture. At this time, the rotary actuator rotation angle sensor 3 detects the roll angle of the vehicle.

If there is no left or right inclination, that is, there is no roll angle, there is no change in the left and right height, so the rotation angle of the actuator becomes 0 (zero), which is the target value of the vehicle control.

When the roll angle is generated from the driving conditions of the outside and the side vehicle, the controller 8 detects this from the rotary rotation angle sensor and starts the operation control operation. At this time, the information detected from the steering sensor and the vehicle speed sensor is based on the vehicle dynamics. By operating the feed forward control to induce a quick response of the system. The control block diagram used at this time is shown in FIG.

The control unit controls the respective valves 15 and 16 by controlling and outputting the current value in various ways such as PWM (Pulse Width Modulation).

By controlling the operation of the valve, the flow rate flowing into the front and rear rotary actuators is controlled, and the rotation angle of the rotary actuators is controlled to finally control the roll angle of the vehicle. At this time, the rotation angle of the rotary actuator is fed back to the first input as in the block diagram of the control unit shown in FIG. 9 to repeat the control until a satisfactory minimum roll angle is obtained.

The present invention focuses on the fact that the change in the weight of the vehicle is actually unpredictable and the weight detection through the load sensor is a cumbersome process. Only the roll angle is fed back to control the actuator rotation angle.

This is intended for general application, which is independent of the weight variation of the vehicle of the invention.

The constant interval maintenance function by the system failure is performed by switching the opening degree of the on / off valve (16, 16) by the detection signal of the abnormal state detector or the electrical failure.

When the on / off valves 13 are opened, both chambers of the rotary actuator are closed to obtain the effect of increasing the rigidity of the stabilizer.

The lack of stiffness of the stabilizer when the vehicle is driving on the flat road helps the ride comfort of the vehicle, which requires a circuit for opening both chambers of the rotary actuator. To this end, the on / off valves 16 and 16 are opened to allow the actuator to rotate freely.

The direction control valves 15 and 15 used in the present invention perform the function of maintaining the required rigidity of the vehicle by setting the pressure of the return-side pipeline at the set pressure according to the characteristics of the applied vehicle. That is, the opening of the directional control valve controlled by the proportional solenoid is performed. At this time, the discharge flow rate can be adjusted by changing the opening degree of the directional control valve, and the opening degree serves as a kind of damping orifice.

Therefore, the active roll control device of the present invention is required to change the opening degree of the directional control valves 15 and 15 in the case where a continuous conversion from the rigid soft mode to the hard mode is required or when a system failure occurs. The rigidity of the hydraulic rotary actuator is controlled by adjusting the discharge flow rate.

According to the configuration of the present invention as described above, by controlling the hydraulic flow rate of the hydraulic actuator attached to the front and rear wheels of the vehicle to actively control the state of movement of the vehicle, it is possible to simultaneously realize the ride comfort and steering safety that can not be obtained in the conventional manual stabilizer Will be.

In addition, there is a significant energy saving effect compared to the active suspension used for similar purposes, and thus a simple combination structure of the proportional directional control valves 15 and 15 and the on / off valves 16 and 16 used in the present invention. By this, a rotational displacement in any operating direction of the stabilizer with the hydraulic rotary actuator is generated to perform roll control of the vehicle, and the rigidity control of the stabilizer is executed by the opening amount of the directional control valve capable of flow control.

In addition, the present invention can detect the attitude of the vehicle directly through the rotation angle sensor attached to the rotary actuator to determine the control target of the controller, so that it is possible to control the attitude consistently regardless of the change in the vehicle conditions.

Furthermore, the driver's steering operation is faster than the roll movement of the vehicle, and the information detected by the steering angle sensor and the vehicle speed sensor is calculated to calculate and output the current control value having the minimum error to the required current value. A control structure that quickly reaches the target improves the roll control effect.

In addition, it is possible to directly control the attitude without detecting the load weight of the truck, the number of passengers of the passenger car, etc. separately, thereby reducing the cost and simplifying the device.

As mentioned above, the present invention has been described in detail with reference to a preferred embodiment of the present invention shown in the accompanying drawings, which is merely one example to help understanding of the present invention, and the present invention is limited to these preferred embodiments. Various modifications and variations are possible without departing from the spirit and scope of the present invention.

Claims (8)

In the active roll control apparatus for a vehicle having each of the front and rear wheels of the vehicle having a sensor unit, a hydraulic control valve unit, a rotary actuator, a control unit and a hydraulic source, the sensor unit is composed of a vehicle speed sensor, a steering angle sensor, a rotary actuator rotation angle sensor, The valve unit includes a proportional direction control valve and an on / off valve, and the proportional direction control valve determines the rotation direction and the rotation angle of the rotary actuator by adjusting the opening degree, and the on / off valve is the amount of the rotary actuator. Arranged between the ports, the actuator receives the hydraulic oil from the proportional directional control valve to generate a torque and to rotate, the opposite ends of the actuator in the opposite direction around the rotary actuator to control the roll phenomenon of the vehicle Attached stabilizer bar for relative movement limits maximum rotation angle Thereby mechanically setting the critical roll angle of the vehicle, wherein the control unit detects the information of the vehicle from the sensors and adjusts the current applied to the front and rear wheel infant valve unit based on the detected information to direct or open the valve unit. Active roll control device for a vehicle, characterized in that for controlling the operation of the actuator by adjusting. The proportional direction control valve according to claim 1, wherein the proportional direction control valve is a tandem center proportional direction control valve, and determines the rotation direction and the rotation angle of the rotary actuator, and the operation of the control device is unnecessary, such as when the vehicle travels on a flat road. When the hydraulic discharge amount of the pump is all configured to bypass the active roll control device for a vehicle. 2. The stabilizer of claim 1, wherein the stiffness of the stabilizer is made almost zero by opening the proportional control valves and the on / off valves so that the actuator can be freely rotated when driving on a flat road as needed during vehicle driving. And an opening of the proportional control valve and the on / off valve in the event of a malfunction such as a system failure. The hydraulic rotary of claim 1, wherein the discharge flow rate is controlled through an opening degree control controlled by a proportional solenoid, and the opening degree serves as a damping orifice, thereby adjusting the discharge flow rate according to the opening degree switching of the directional control valve. An active roll control device for a vehicle, characterized in that for controlling the rigidity of the actuator. The rotary actuator of claim 1, wherein a rotary angle sensor is attached to directly detect a vehicle posture, and a feed forward control roll is used by using a reference weight, and the actuator rotation angle is fed back to obtain a satisfactory minimum roll angle. An active roll control device for a vehicle, characterized in that the control is repeatedly performed until further and only additional roll angles are controlled by other condition changes. The method of claim 1, wherein the control unit detects this from the rotary rotation angle sensor when the roll angle is generated from the driving condition of the vehicle, and starts the operation control operation, wherein the information detected from the steering sensor and the vehicle speed sensor is based on the vehicle dynamics. It controls feedforward by controlling the output value by various methods such as PWM (Pulse Width Modulation), and controls each valve and controls the front and rear rotary actuator by the valve operation. Finally, the roll angle of the vehicle is controlled by controlling the incoming flow rate and the rotation angle of the rotary actuator. At this time, the control is repeated until the rotation angle of the rotary actuator is fed back to the first input to obtain a satisfactory minimum roll angle. Active roll control device for a vehicle, characterized in that performing. The active roll control apparatus for a vehicle according to claim 1, wherein the hydraulic pressure source is constituted by a motor-driven hydraulic pump with a relief valve type. The active roll device for a vehicle according to claim 1, wherein the hydraulic pressure source comprises an engine driven hydraulic pump with a relief valve type.