KR100215477B1 - Active roll control system for an automobile - Google Patents

Abstract

[purpose]

The present invention relates to a vehicular stabilizer system in which a relief valve and a proportional directional control valve are provided to continuously control a linear hydraulic actuator to suppress roll phenomenon caused by a running state, And control the pressure of the rotary hydraulic actuator at the time of steering to improve the control, maneuverability and stability of the vehicle attitude at the same time, reduce the change of the attitude of the vehicle at the time of steering and turning, optimize the movement characteristics of the vehicle, And more particularly, to a vehicle active roll control system using a hydraulic linear actuator with a displacement sensor.

[Configuration]

The present invention relates to a sensor unit (1) comprising a vehicle speed sensor, a steering angle sensor and a gravity actuator displacement sensor; A front wheel valve unit (2) composed of a tandem center type proportional directional control valve and an on / off valve; A front wheel actuator 3 for receiving a hydraulic oil from a proportional directional control valve to generate a displacement and performing linear motion, a stirrer and a tire portion attached to both ends thereof, and controlling roll phenomenon of the vehicle; A rear wheel valve unit 4 and a rear wheel actuator unit 5 and detects the information of the vehicle from the sensor to regulate currents imposed on the front and rear wheel hydraulic valve units 2 and 4, A control unit 6 for controlling an actuator operation for control, and an active roll control apparatus for a vehicle using a hydraulic linear actuator with a displacement sensor.

Description

Active roll control system using hydraulic linear actuator with displacement sensor

FIG. 1 is an explanatory diagram showing a roll developing control means of the prior art;

2 and 3 are a system circuit diagram illustrating the control system of the embodiment of the present invention.

4 is a plan view showing the front wheel actuator structure of the embodiment of the present invention

5 is a front section view of FIG. 4

FIG. 6 is a view for explaining generation of power by a linear actuator and stabilizer of the embodiment of the present invention;

7 and 8 are views showing another embodiment of the hydraulic linear actuator of the present invention

9 is a block diagram of a control block of the embodiment of the present invention.

DESCRIPTION OF THE DRAWINGS FIG.

1: Sensor unit 2: Front wheel valve unit

3: front wheel actuator unit 4: rear wheel valve unit

5: rear wheel actuator unit 6:

The present invention relates to a vehicular stabilizer system in which a relief valve and a proportional directional control valve are provided to continuously control a linear hydraulic actuator to suppress roll phenomenon caused by a running state, And control the pressure of the rotary hydraulic actuator at the time of steering to improve the control, maneuverability, and stability of the vehicle attitude at the same time. By reducing the change of the attitude of the vehicle during steering and turning, it is possible to optimize the driving characteristic of the vehicle, And more particularly, to an active roll control system for a vehicle using a hydraulic linear actuator with a displacement sensor attached thereto.

A so-called passive stabilizer bar is known for controlling roll phenomenon of a vehicle by a conventional stabilizer.

As a concrete structure of the passive stirrer bar, for example, as shown in FIG. 1, it serves as a kind of torsion spring. When the vehicle turns, a lateral acceleration is generated by the winch thrust, The weight of the vehicle is excessively transferred to one side and the slip occurs in the tire to deteriorate the steering performance. In order to prevent this, the front wheel and the rear wheel The right and left knuckles are connected by a stabilizer so that the torque due to the difference in height between the left and right sides is compensated by the torque corresponding to the angular displacement of the stabilizer bar.

However, since the conventional stirrer bar has a fixed rigidity, it can not cope with various sudden changes in driving conditions and only passively reacts to the outer roll moment. Accordingly, when the stiffness of the stirrer is increased, However, there is a problem that ride comfort is greatly deteriorated. Conversely, if the stiffness of the stabilizer is reduced, the roll phenomenon becomes excessive, which seriously affects the safety of the running of the vehicle.

On the other hand, in view of the above, an active roll control device using roll control has been proposed. However, since the active roll control device operates only in response to a preprogrammed response method, The valve unit that controls the hydraulic actuator was relatively stiff and the system employs a hydraulic rotary actuator, but the manufacture of the hydraulic rotary actuator was difficult, And the like.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a continuous control system employing a hydraulic linear actuator; A hydraulic system using a proportional directional control valve for roll control, a hydraulic circuit for stiffness removal function during flat travel, a directional control valve with a flow control function at the time of accident or system accident, It is composed of active roll control means which can change the vehicle type by switch without structural change by controlling the pressure change rate and discharge flow rate according to the applied vehicle type and can be controlled with the linear actuator displacement sensor And a combination of a hydraulic linear actuator and a stabilizer. The control means is composed of three types of sensors for quick system response and a feed forward of the steering angle and the vehicle speed and feedback of the linear actuator displacement sensor. Detailed description will be made in accordance with the accompanying drawings and examples. It is as follows.

2 and 3, the present invention mainly includes a sensor unit 1, a front wheel valve unit 2, a front wheel actuator unit 3, a rear wheel valve unit 4, a rear wheel actuator unit 5, And the sensor unit 1 is composed of only three sensors such as a vehicle speed sensor, a steering angle sensor, and a gravity displacement sensor. The vehicle speed sensor and the steering angle sensor are mostly mounted on existing commercial vehicles The actuator displacement sensor can detect the roll angle of the vehicle in various forms and its configuration is simpler than the configuration of the vehicle's attitude detecting device used in all other intelligent active systems.

The tandem-type proportional directional control valve determines the traveling direction and the displacement amount of the hydraulic linear actuator, and determines whether the vehicle is traveling on a flat road The tandem-type proportional directional control valve is installed to bypass the pump discharge flow when the operation of the system is not necessary, and an on-off valve is disposed between the two ports of the hydraulic linear actuator, By opening the opening, the rigidity of the stabilizer is made almost zero (zero). In case of malfunction such as system failure, the opening is closed to obtain a greater mechanical rigidity than the conventional passive stabilizer.

As shown in FIGS. 4 and 5, the front wheel actuator 3 is supplied with operating fluid from the proportional directional control valve to generate a displacement. The stabilizer and the tire portion are attached to both ends of the hag actuator, When the hydraulic linear actuator is operated to control the phenomenon, a worm force is generated in opposite directions with respect to a certain roll, and the generation of woofer by the linear actuator and the stabilizer is shown in Fig. In addition, the linear actuator is designed to limit a certain maximum displacement to mechanically set the critical roll angle of the vehicle.

The valve unit 2 of the front wheel valve unit 4 and the rear wheel actuator unit 5 of the rear wheel valve unit 4 are identical in construction and function to the front wheel actuator unit 3.

The controller 6 detects the information of the vehicle from the sensors and controls the currents to be applied to the front and rear wheel hydraulic valve units 2 and 4 to control the actuator operation for the desired roll control. A motor driven hydraulic pump with a relief valve integrated with the tank or an engine driven hydraulic pump is used. In the case of a motor driven type, energy is saved by disconnecting the power of the motor when it is not needed. In the case of an engine driven type, Energy saving is possible by bypass function of proportional direction control valve. The oil discharged from the hydraulic pump with the relief valve and the tank is supplied to the hydraulic pressure valve unit and the chamber of the hydraulic linear actuator corresponding to the front and rear wheels and exerts a force on the stabilizer connected with the linear actuator And controls the motion state of the vehicle,

At this time, the system operating pressure of the embodiment of the present invention is set by the relief valve attached to the pump, and the motion state of the vehicle is detected by the linear actuator displacement detector, the steering angle detector and the lateral acceleration detector, In this case, the rotation angle sensor of the rotary actuator detects the roll angle of the vehicle, and when there is no right or left tilt, that is, when there is no roll angle, the change in the vehicle height The displacement of the actuator becomes 0 (zero), and this angle becomes the target value of the vehicle control. When the roll angle is generated from the outside, that is, the vehicle driving condition, this is detected from the hydraulic linear actuator displacement sensor, . At this time, the information detected from the steering angle sensor and the vehicle speed sensor is calculated based on the vehicle dynamics to perform feedforward control to induce quick response of the system, and to control the actuator displacement as a feedback element As shown in FIG. 9, in the control block diagram, the control unit controls and outputs the current value by various methods such as PWN (Pu1se Width Modulation) and the like, and controls the respective valves by controlling the front and rear wheel actuators So that the roll angle of the vehicle is finally removed by controlling the differential angle of the actuator.

At this time, the rotation angle of the actuator is fed back to the first input in the block diagram of the control unit, and the control is repeated until a satisfactory minimum roll angle is obtained. The weight variation of the vehicle is actually unpredictable, and the weight detection through the load sensor is cumbersome Therefore, it is intended for general application regardless of the weight change of the hawk vehicle to feed forward control to the standard weight and feed back to the actuator displacement amount only the additional roll angle due to the change of the other condition, and the constant stiffness maintenance function by the system failure is intended When the on-off valve is opened by opening or closing the on-off valve by a detection signal or an electrical failure of the abnormal state detector, both chambers of the actuator are closed to obtain the effect of increasing the stiffness of the stabilizer. The lack of stiffness of the stabilizer means that For this purpose, the on-off valve is opened to open both chambers of the actuator so that the actuator can rotate freely.

The directional control valve maintains the required stiffness of the vehicle by setting the pressure of the back-side pipe to the set pressure according to the characteristics of the applied vehicle, performs opening switching of the directional control valve controlled by the proportional solenoid, The discharge flow rate can be adjusted according to the opening degree. The opening serves as a kind of damping orifice. In the case of the demand for continuous conversion from the rigid soft mode to the hard mode or the system failure, And the rigidity of the hydraulic linear actuator is controlled by adjustment. An example of mounting the stabilizer of the hydraulic linear actuator removes unnecessary components by the linear actuator as shown in FIGS. 7 and 8, There are various methods, and one of them is exemplified in the present invention.

The driving state of the vehicle is actively controlled by controlling the inflow flow rate of the hydraulic actuator attached to the front and rear wheels of the vehicle so that the ride comfort and the steering stability that can not be obtained by the conventional stabilizer can be realized at the same time, Therefore, a simple combination structure of the proportional directional control valve and the on-off valve used in the present invention produces a linear displacement in any operating direction of the stabilizer to which the hydraulic actuator is attached The stiffness control of the stabilizer can be performed by controlling the roll of the vehicle and the amount of opening of the directional control valve capable of controlling the flow rate and the present invention can directly detect the attitude of the vehicle through the displacement sensor attached to the hydraulic actuator Since the control target of the control section is determined, The steering angle sensor and the vehicle speed sensor calculate the information detected by the steering angle sensor and the vehicle speed sensor by using the fact that the driver's steering operation is faster than the roll motion of the vehicle more consistently, To perform the initial control, and to improve the roll control effect to a control structure that reaches the target quickly.

In addition, it is possible to perform direct attitude control without detecting the loading weight of passenger cars and the passengers of passenger cars, so that it is possible to reduce the cost and simplification. Especially, in comparison with the method of pursuing roll control using a rotary actuator, The rotary actuator is difficult to manufacture and the manufacturing cost is very high. However, since the hydraulic linear actuator is very widely used, it is easy to manufacture and its stability and economical efficiency will be recognized.

Further, it is very easy to mount the linear actuator in the present invention, and it is possible to control essential performance required in the hydraulic circuit of the active roll control apparatus, that is, to control the tractive force of the tire at the time of turning and to change the stiffness of the stabilizer according to the traveling mode of the vehicle It is possible to maintain the control pressure of maintaining smooth pressure fluctuation and constant stiffness when system failure occurs. It is easy to return the system pressure and has a simpler structure than other high performance active suspension devices of the same purpose. It has low volume and weight and low energy consumption. And is not limited to the above.

Claims (4)

A sensor unit 1 composed of a vehicle speed sensor, a steering angle sensor, and an actuator displacement sensor; A front wheel valve unit (2) composed of a tandem center type proportional directional control valve and an on / off valve; A front wheel actuator 3 for receiving a hydraulic oil from a proportional directional control valve to generate a displacement and performing linear motion, a stirrer and a tire portion attached to both ends thereof, and controlling roll phenomenon of the vehicle; A rear wheel valve unit 4 and a rear wheel actuator unit 5 and detects the information of the vehicle from the sensor to regulate currents imposed on the front and rear wheel hydraulic valve units 2 and 4, And a control unit (6) for controlling an actuator operation for controlling the vehicle. The active roll control apparatus for a vehicle using the hydraulic linear actuator with a displacement sensor. 2. The apparatus according to claim 1, wherein the sensor unit (1) comprises only three sensors such as a vehicle speed sensor, a steering angle sensor, and an actuator displacement sensor, and the actuator displacement sensor is configured to directly detect a roll angle of the vehicle Active Roll Control System for Vehicle Using Hydraulic Linear Actuator with Displacement Sensor. 2. The hydraulic control apparatus according to claim 1, wherein the front wheel valve unit (2) is constituted by a tandem center type proportional direction control valve and an on / off valve, and the tandem center type proportional direction control valve determines a traveling direction and a displacement amount of the hydraulic linear actuator And a tandem-centered proportional directional control valve for bypassing all of the pump discharge flow when the vehicle runs on a flat road and the operation of the system is unnecessary, and an on-off valve is disposed between the two ports of the hydraulic linear actuator Characterized in that the active roll control device for a vehicle using a hydraulic linear actuator with a displacement sensor. The control apparatus according to claim 1, wherein the controller (6) detects information of a vehicle from a sensor to control currents imposed on the front and rear wheel hydraulic valve units (2, 4), controls an actuator for roll control, Wherein the control unit is configured to have a bypass function of a tandem-centered proportional directional control valve with a relief valve-mounted motor-driven hydraulic pimp as an oil pressure source as a whole, and an active roll for a vehicle using the hydraulic linear actuator with a displacement sensor Control device.