KR100397264B1 - Electronic suspension apparatus - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled suspension device for determining damping force of dampers in a four-wheel independent suspension device employing a continuous damping force variable damper. Ride comfort control logic (10) for detecting; First and second roll values for adjusting the damping force in response to the vehicle speed and steering angle of the vehicle ( Anti roll control logic 20 for calculating; A squat value for detecting a change in the opening angle of the vehicle and adjusting the damping force in response to the change amount ( Anti-squat control logic (30) to detect; Dive value for adjusting the damping force in response to the deceleration when the vehicle is decelerated above the predetermined deceleration to control the pitch movement of the vehicle ( Anti-dive control logic 40 for detecting; Vehicle speed sensitive signal for adjusting damping force in response to vehicle speed ( Vehicle speed sensitive control logic 50 for detecting; Ride value ( ), First and second roll values ( ), The squat value ( ), Dive value ( ) And vehicle speed response signal ( Damping force provided to the dampers of each wheel in response to Is provided with a damper control circuit (60).

Description

Electronically controlled suspension device {ELECTRONIC SUSPENSION APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device for a vehicle, and more particularly, to an electronically controlled suspension device for adjusting a damping force of a damper according to a driving state of a vehicle in a four-wheel independent suspension device employing a continuous damping force variable damper.

Suspension is a device that connects the axle and the body so that vibrations or shocks received by the axle from the road surface are not directly transmitted to the body while driving, thereby preventing damage to the body and cargo and enhancing ride comfort. In addition, the suspension device transmits the driving force generated in the driving wheels or the braking force of each wheel during braking to the vehicle body, and also withstands the centrifugal force during the turning and maintains each wheel in the correct position with respect to the vehicle body.

On the other hand, according to the technological development of the suspension system, a four-wheel independent control suspension system using a continuous damping force variable damper has been developed.In the suspension system, various sensors are mounted in the vehicle, and the ride comfort and adjustment are controlled by controlling the damper according to the information from the sensor. Stability is improved. However, since the efficiency is extremely different depending on which sensor is used in such a suspension system and how the information from the sensor is used to control the damper, the development of a device capable of controlling the damper most efficiently in the suspension system field is developed. This is desired.

In response to this need, the present inventor has filed an "electronic controlled suspension device" (Application No. 98-45753). In the present invention, the present inventors have provided an electronically controlled suspension device which improves ride comfort and adjustment stability by controlling the damping force of the damper in the four-wheel independent suspension device by combining information of all possible states that may occur when the vehicle is running.

In this electronic control unit, the damping force to be applied to each wheel ( ) Was detected using Equation 1.

here, Subscript Means four wheels, and posneg means a sign that changes according to the left and right wheels of the vehicle as shown in FIG. The bodywork vertical speed, Is a roll value for adjusting the damping force corresponding to the vehicle speed and steering angle of the vehicle, Is a ride comfort value for controlling the damping force in response to the vertical acceleration of the wheels, D is a dive value for adjusting the damping force in response to the deceleration when the vehicle is decelerated above a predetermined set deceleration to control the pitch movement of the vehicle, and Denotes a squat value for detecting a change in the opening angle of the vehicle and adjusting the damping force in response to the change amount.

In addition, min and max means the minimum and maximum of the actuator, the damping force ( ) Is the neutral position ( It can be seen that it has an integer value between the minimum value (min) and the maximum value (max) of the actuator, based on).

On the other hand, in the conventional invention, the roll value ( ) Was detected in the following anti-roll control logic in the following manner.

First, in the related art, the lateral acceleration (the movement of the wheel with respect to the steering input angle) is expressed using Equation (2). ) The steering ratio ( ).

here, Is the steering gear ratio, Is the steering wheel angle rate (rad / sec), Is the wheel base, V is the vehicle speed (m / sec), and Is the characteristic speed.

In Equation 2, MKS and radian are used, and a counterclockwise steering input is used as a positive sign.

On the other hand, in a real system, the lateral acceleration for steering input ( Since the output of) has a 1sr order delay, the lateral acceleration ( ), The low frequency filtering results in a lateral acceleration value ( ) Should be obtained.

Where T _delay1 is the variable value for the time delay.

And this lateral acceleration ( ) And the roll value ( ) Was obtained.

here Is a variable meaning a predetermined gain value.

Meanwhile, the damping force in Equation 1 ) Is the roll value ( ), But the ride value ( ) And dive value ( ) Is 0 in normal state, so the roll value ( ) Is the damping force ( Does not affect). That is, if the driver changes the steering angle, the roll value ( ) Fluctuates, but at this time, ) And dive value ( ) Is 0, so the damping force ( ) Does not change. However, as the actual rotation angle of the vehicle changes due to the change of the steering angle, the riding comfort value ( ) And dive value ( ) Changes and accordingly the damping force ( ) Changes.

Where the roll value ( Damping force due to the change of We can see that the response of) is late. That is, the roll value ( Damping force by The control is intended to be a feed forward control method, but is substantially performed by a feed back control method.

Thus, in the conventional method, the roll value ( Damping force due to the change of ) Has a disadvantage of slow response.

The present invention is to solve this problem, the object of the present invention is to provide a roll value ( ), The damping force ( The present invention provides an electronically controlled suspension device capable of responding immediately.

In order to achieve the above object, the present invention is a device for determining the damping force of the dampers in a four-wheel independent suspension device employing a continuous damping force variable damper, the ride comfort control for detecting a ride comfort value for controlling the damping force corresponding to the vertical acceleration of the wheels Logic; Anti-roll control logic for calculating first and second roll values for adjusting the damping force corresponding to the vehicle speed and the steering angle of the vehicle; Anti-squat control logic for detecting a change in the opening angle of the vehicle and detecting a squat value for adjusting the damping force in response to the change amount; Anti-dive control logic for detecting a dive value for adjusting the damping force in response to the deceleration when the vehicle is decelerated above the predetermined deceleration to control the pitch movement of the vehicle; Vehicle speed sensitive control logic for detecting a vehicle speed sensitive signal for adjusting the damping force in response to the vehicle speed; And a damper control circuit for determining a damping force provided to dampers of each wheel in response to a ride comfort value, first and second roll values, squat values, dive values, and vehicle speed sensitive signals.

1 is a view showing a setting state of posneg in the damper control circuit in the electronically controlled suspension device according to the present invention;

2 is a schematic block diagram of an electronically controlled suspension device according to the present invention;

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

10: ride comfort control logic 20: anti-roll control logic

30: anti squat control logic 40: anti dive control logic

50: vehicle speed sensitive control logic 60: damper control circuit

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

2 is a schematic block diagram of an electronically controlled suspension device according to the present invention. According to the present invention, as shown, ride control logic 10, anti-roll control logic 20, anti-squat control logic 30, anti It is composed of a dive control logic (Anti-Dive Control Logic) 40, a vehicle speed sensitive control logic (Speed Depedent Control Logic) 50, a damper control circuit 60, and a variety of sensors (S1-S8).

Here, the ride comfort control logic 10 is a ride comfort value for controlling the damping force corresponding to the vertical acceleration information from the vertical acceleration sensor (S1-S4) for detecting the vertical acceleration of the four wheels in the vehicle, respectively ( ) And bodywork vertical speed ( ) Is detected and output.

The anti-roll control logic 20 is to suppress the roll motion of the vehicle by increasing the damping force of the damper during steering of the vehicle, and is connected to the vehicle speed sensor S5 and the steering angle sensor S6 as shown. That is, the anti-roll control logic 20 detects the steering input of the driver and controls the transient area of the body behavior. The anti-roll control logic 20 detects the steering angular velocity by inputting a signal from the steering angle sensor S6. In order to detect the amount of change in the lateral acceleration and the first and second roll values in consideration of the vehicle speed from the vehicle speed sensor S5.

The anti-roll control logic 20 calculates a roll value by sequentially performing the above-described equations (2), (3) and (4), and the roll value is the first roll value ( Set to).

In addition, the anti-roll control logic 20 of the present invention is the lateral acceleration detected by the equation (2) The absolute value is taken as the change amount of) and low-frequency filtering is performed through the filter of Equation 5.

And this lateral acceleration ( ) And the second roll value ( )

here Is a variable meaning a predetermined gain value.

The anti-squat control logic 30 detects a change in the opening angle of the vehicle by the throttle position sensor S7, and corresponds to a squat value for adjusting the damping force in response to the change amount. ) Is detected and output.

The anti-dive control logic 40 responds to the deceleration when the vehicle is decelerated above a predetermined set deceleration to control the pitch movement of the vehicle by the information from the vehicle speed sensor S5 and the brake on off detection sensor S8. Dive value for adjusting the damping force ( ) Detects and outputs the vehicle speed sensitive control logic 50 to adjust the attenuation force corresponding to the vehicle speed according to the information of the vehicle speed sensor S5. ) Is detected and output.

The damper control circuit 60 has the above-mentioned ride comfort value ( ), Roll value ( ), The squat value ( ), Dive value ( ) And vehicle speed sensitive signal ( Damping force provided to the dampers of each wheel in response to Is determined.

That is, the damper control circuit 60 synthesizes the signals from each of the above-described logics 20, 30, 40, and 50, and performs the above equation (7) so that the damping force to be applied to each wheel ( To control the damper drive.

here, Subscript Denotes four wheels, and posneg denotes a code that varies according to the left and right wheels of the vehicle, as shown in FIG.

As can be seen from Equation 7, ) Is the roll value ( ) Changes immediately. That is, if the driver changes the steering angle, the roll value ( ) Fluctuates, resulting in a ride value ( ) And dive value ( Even if) is 0 Value changes immediately, so the damping force ( ) Responds immediately to changes in steering angle.

Thus, in the present invention, the roll value ( Damping force due to the change of The response is fast, so the feedforward control of the steering angle change is possible.

Thus, in the present invention, the damping force ( ) Has the effect of being able to respond immediately.

Claims (3)

delete In the device for determining the damping force of the dampers in a four-wheel independent suspension device employing a continuous damping force variable damper, Riding comfort value for controlling damping force corresponding to the vertical acceleration of the wheels Ride comfort control logic for detecting; Lateral acceleration, which is the movement of the wheel relative to the steering angle of the vehicle ( ) The steering ratio ( And detect the detected lateral acceleration ( ) Is a low-frequency filtered lateral acceleration value ( ) Is the first gain value ( ) To multiply the first roll value ( ) And the lateral acceleration ( Lateral acceleration value (low-frequency filtered absolute value of) ) Is the second gain value ( ) To multiply the second roll value ( Anti-roll control logic for calculating each); A squat value for detecting a change in the opening angle of the vehicle and adjusting a damping force in response to the detected opening angle change amount ( Anti squat control logic for detecting; Dive value for adjusting the damping force in response to the deceleration when the vehicle is decelerated above the predetermined deceleration to control the pitch movement of the vehicle ( Anti-dive control logic to detect; Vehicle speed sensitive signal for adjusting damping force in response to vehicle speed ( Vehicle speed sensitive control logic for detecting; The ride comfort value ( ), The first and second roll values ( ), The squat value ( ), Dive value ( ) And vehicle speed response signal ( Damping force provided to the dampers of each wheel in response to Electronically controlled suspension comprising a damper control circuit for determining The method of claim 2, The damper control circuit has the following formula Damping force to be applied to each wheel by To control the driving of the damper, Subscript The four wheels, the posneg is an electronically controlled suspension device, characterized in that means a sign that changes depending on the vehicle left and right wheels.