KR19990038414A - Electronically Controlled Damping Force Variable Suspension of Vehicle - Google Patents

Abstract

The present invention relates to an electronically controlled damping force variable suspension of a vehicle to recognize the braking and driving situation of the driver from the vehicle speed sensor mounted on the vehicle to arbitrarily control the damping force of the damping force variable damper to improve ride comfort and steering stability of the vehicle. The differentiator 21 calculates the change amount of the vehicle speed by differentiating the vehicle speed signal detected by the vehicle speed sensor 13 by the controller 17 of the electronically controlled suspension device of the vehicle, and the vehicle speed calculated by the differentiator 21. The vehicle speed pumping change amount calculation unit 22 that calculates only the vehicle speed pumping change amount corresponding to the start of the vehicle from the change amount of the vehicle speed and the vehicle speed pumping change amount calculating unit 22 and the current traveling speed of the vehicle It consists of a proper damping force calculation unit 23 to calculate the appropriate damping force of the vehicle by multiplying the weight according to the By selecting the appropriate damping force of the wheel to control the body movement is effective to minimize the body pitching movement.

Description

Electronically Controlled Damping Force Variable Suspension of Vehicle

The present invention relates to an electronically controlled damping force variable suspension of a vehicle to recognize the braking and driving situation of the driver from the vehicle speed sensor mounted on the vehicle to arbitrarily control the damping force of the damping force variable damper to improve ride comfort and steering stability of the vehicle. will be.

In general, the vehicle is equipped with a suspension that connects the axle and the body so that when the vehicle travels, the axle does not directly transmit vibrations or shocks received from the road surface, thereby preventing damage to the body and cargo, and improving ride comfort and stability. It is improving.

In addition, the suspension system transmits the driving force generated from the wheels or the braking force of each driving wheel to the vehicle body when braking, and withstands centrifugal force when turning, and keeps the driving wheel in the correct position with respect to the vehicle body. In order to alleviate the impact received, flexible coupling is required in the vertical direction, as well as strong coupling in the horizontal direction to withstand the driving force generated by the driving wheel, braking force and centrifugal force during turning.

The suspension system not only modulates the damping force of the variable damper according to the running speed, braking and acceleration of the vehicle, but also adjusts the damping force of the variable damper according to the road even at a constant driving speed, and the damping force of the variable damper is an actuator stepping. It is controlled by driving the motor.

That is, the variable damper is provided with a control rod, and the flow path is changed and the damping force is varied as the actuator is rotated by driving the actuator.

An electronic control suspension system (ECS) of a conventional vehicle is mounted at a corresponding position of the vehicle as shown in FIG. 1, and the controller 7 of the electronic control suspension system has an acceleration in the up / down direction of the vehicle. Vertical acceleration sensor (1) for detecting the vehicle speed, vehicle speed sensor (2) for detecting the vehicle speed, brake sensor (3) for detecting the braking of the vehicle, and Throttle Position Sensor (TPS) (4) for detecting the throttle opening angle of the engine From the signals detected by the sensors and the switches 1 to 6, such as a mode selection switch 5 for converting the control mode and a steering angle sensor 6 for detecting the steering angular velocity of the vehicle, an appropriate damping force of the damper is determined. According to the determined result, the electric actuator 8 located at the top of the damper is driven to change the size of the flow path by the rotation of the control rod, thereby simultaneously controlling the damping force of the four wheel dampers in the hard mode and the medium mode. ium Mode, Soft Mode.

The conventional electronically controlled suspension device drives the actuator with the following six separate logics according to the driving direction of the vehicle. First, the anti-bounce control detects a situation such as bump or rough road driving. If the vehicle speed is greater than V ₁ Kph and the center of gravity of the vehicle, ie, the vertical acceleration of the vehicle located in the console box, is greater than G ₁ g, the actuator is switched to medium, and after t ₁ sec. Return to.

Secondly, ANTI-SHAKE control is designed to make the vehicle move less when passengers get on and off when the vehicle is stopped and when loading and getting off the load.If the vehicle speed is below V ₂ Kph, it is switched to hard. If the vehicle speed is maintained over t ₂ s for more than V ₂₁ Kph, return to the original state.

Third, when the vehicle is traveling at high speed, the high-speed response control to ensure the steering safety of the vehicle is switched to medium when the vehicle speed is maintained at V ₃ Kph or more for t ₃ seconds or more, and the original state when the vehicle speed is V ₃₁ Kph or less. Return to.

Fourth, the ANTI-SQUAT control to minimize the front of the vehicle moving up and down at low speed starts the actuator when the vehicle speed is less than V ₄ Kph and the engine throttle opening angle is greater than θ ₄ Deg. Switch to medium, and switch to medium or hard in its original state if t ₄ seconds have elapsed or if the vehicle speed is V ₄₁ Kph or more.

Fifth, the ANTI-DIVE control to minimize the movement of the front part of the vehicle in the downward direction during braking at medium and high speed is to harden the actuator when the brake switch is turned on by braking above the vehicle speed V ₅ Kph. When t ₅ seconds have elapsed from the time when this condition is not satisfied, the actuator is switched to medium or hard.

Finally, the anti-roll control to ensure the stability of the vehicle during steering is performed at V ₆₁ Kph, V ₆₂ Kph, V ₆₃ Kph and V ₆₄ Kph when the vehicle speed is greater than V ₆ Kph. If the steering angular velocity is greater than θ ₆₁ Deg / sec, θ ₆₂ Deg / sec, θ ₆₃ Deg / sec, θ ₆₄ Deg / sec, respectively, switch to hard, and when t ₆ seconds have elapsed since this condition was released, Returns to the state of.

As described above, the driving direction motion control logic of the conventional electronically controlled suspension device has a small damper damping force stage and simultaneously controls the damping force of each wheel to increase the damping force of each wheel so as to reduce the pitching movement of the vehicle during rapid start, rapid braking, and high speed driving. Doing.

However, the conventional electronically controlled suspension system detects the starting movement of the vehicle using only the opening angle, thereby reducing the riding comfort by suddenly raising the damping force without considering the movement of the vehicle even when the direct movement does not occur. There is a problem in that unnecessary damping force control is frequently performed.

The present invention has been made to solve the above problems, the object is to recognize the braking and driving situation of the driver from the vehicle speed sensor mounted on the vehicle to minimize the pitching which is the driving direction movement by arbitrarily controlling the damping force of the damper, An object of the present invention is to provide an electronically controlled damping force variable suspension device for a vehicle to improve road traction and improve vehicle comfort and driving stability at the same time.

In order to achieve the above object, the electronically controlled damping force variable suspension device of the present invention calculates an amount of change in vehicle speed by differentiating a vehicle speed signal detected from a vehicle speed sensor, and calculates the amount of change in the vehicle speed, and the vehicle corresponding to the start of the vehicle from the amount of change in the vehicle speed. After calculating only the amount of change in speed, multiply the amount of change in vehicle speed by the weight according to the running speed of the vehicle to calculate the value indicating the start of the vehicle, and then change the damping force of the damping force variable damper in a large direction according to the displayed value. It is characterized in that the pitching movement at the time of sudden start of the vehicle is suppressed.

1 is a view showing a state in which a conventional electronic control suspension is mounted on a vehicle,

2 is a view showing a state in which the electronically controlled damping force variable suspension of the vehicle according to the present invention mounted on the vehicle,

3 is a block diagram of a controller of the electronically controlled damping force variable suspension according to the present invention;

4 is a graph showing weights according to vehicle speed.

<Explanation of symbols for main parts of the drawings>

13 vehicle speed sensor 17 controller

18: variable damper and actuator 21: differentiator

22: vehicle speed pumping change amount calculation unit 23: appropriate damping force calculation unit

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the electronically controlled damping force variable suspension device according to the present invention.

2 is a view showing a state in which the electronically controlled damping force variable suspension of the vehicle according to the present invention is mounted on the vehicle, a vertical / left and right acceleration sensor 11 for detecting the acceleration in the up / down, left / right direction of the vehicle, An axle vertical acceleration sensor 12 for detecting acceleration in the vertical direction of the axle, a vehicle speed sensor 13 for detecting the speed of the vehicle, a brake sensor 14 for detecting it when braking the vehicle, and a throttle opening angle of the engine The damping force of the variable damper of each wheel is determined by determining the appropriate damping force from the TPS 15 for detecting the pressure difference, the mode selection switch 16 for switching the control mode, and the signals detected by the sensors and the switches 11 to 16. A controller 17 which outputs an actuator drive signal for the purpose, and a variable damper and actuator 18 of each wheel driven in accordance with the drive signal output from the controller 17 are mounted on the vehicle.

The variable damper and the actuator 18 are composed of a damping force variable damper and a stepping motor type actuator, and the damping force of the damping force variable damper is driven by a stepping motor-type actuator located at the top of the damper to rotate a damper control rod. By varying the size, the damping force of the four-wheel damper is adjusted individually.

3 is a block diagram of the controller 17, which differentiates the vehicle speed signal detected by the vehicle speed sensor 13 to calculate a change amount of the vehicle speed, and a vehicle speed calculated by the differentiator 21. As shown in FIG. The vehicle speed pumping change amount calculation unit 22 that calculates only the vehicle speed pumping change amount corresponding to the start of the vehicle from the change amount of the vehicle speed and the vehicle speed pumping change amount calculating unit 22 and the current traveling speed of the vehicle Proper damping force calculation unit 23 for multiplying the weight according to calculate the proper damping force of the vehicle.

4 is a graph showing a weight (W) according to the running speed of the vehicle.

Referring to the operation of the electronically controlled damping force variable suspension device configured as described above in detail as follows.

The driving direction motion control logic applied to the electronically controlled damping force variable suspension according to the present invention is a control method at the rapid start, and detects the starting time to control the behavior of the vehicle generated at this time.

First, the controller 17 detects the start of the vehicle from the vehicle speed signal detected by the vehicle speed sensor 13. In this case, the differentiator 21 of the controller 17 differentiates the vehicle speed signal as shown in Equation (1) below. Calculate the value corresponding to the amount of change in vehicle speed.

(One)

Subsequently, the vehicle speed positive amount change calculation unit 22 calculates and calculates only the vehicle speed positive amount change corresponding to the start of the vehicle from the amount of change in the vehicle speed calculated by the differentiator 21 as shown in Equation (2) below.

(2)

Then, the appropriate damping force calculator 23 selects the appropriate damping force by multiplying the positive change amount of the vehicle speed obtained by the vehicle speed pumping amount change calculator 22 and the weight according to the vehicle speed of FIG. 4.

At this time, the method of selecting the damping force is shown in Equation (3) below.

(3)

The result value of Equation (3) is a value indicating how quickly the vehicle started and, if the value is less than the value Q1, the stepping motor-type actuator is driven to maintain the damping force of the variable damper in a soft state. If it is between Q1 and Q2, the stepping motor-type actuator is driven to maintain the damping force of the variable damper in the medium state.

As described above, the present invention detects the rapid start or sudden braking of the vehicle from the vehicle speed signal detected by the vehicle speed sensor, minimizes the body pitching motion by selecting the appropriate damping force of each wheel during the sudden start or sudden braking. There is an effect that becomes possible.

Claims (2)

Vertical / left / right acceleration sensor 11, axle vertical acceleration sensor 12, vehicle speed sensor 13, brake sensor 14, TPS 15, mode selection switch 16, the sensor and The electronics of the vehicle comprising a controller 17 for outputting an actuator drive signal in accordance with the signals detected by the switches 11 to 16, and a variable damper and actuator 18 driven in accordance with the drive signal output from the controller 17. In the control suspension, The controller 17 calculates the amount of change in the vehicle speed by differentiating the vehicle speed signal detected by the vehicle speed sensor 13, and from the amount of change in the vehicle speed calculated by the differentiator 21 to start the vehicle. The vehicle speed pumping change amount calculating unit 22 that calculates only the corresponding vehicle speed pumping change amount, and the vehicle speed pumping change amount calculating unit 22 multiplied by the weight according to the current traveling speed of the vehicle An electronically controlled damping force variable suspension apparatus for a vehicle, characterized in that it comprises a proper damping force calculation unit (23) for calculating an appropriate damping force. 2. An electronically controlled damping force variable suspension apparatus according to claim 1, wherein said differentiator (21) uses a filter as in the following formula (1). (One)