ELECTRONIC CONTROLLED SUSPENSION SYSTEM USING WHEEL SPEED

The present invention relates to an electronic suspension control system (ECS) not using a G sensor and a steering angle sensor but using an ECS control algorithm and an ABS wheel speed sensor in order to perform rough road detecting and roll controlling. The ECS includes a wheel speed sensor for measuring the front and rear wheel speed; a throttle position sensor (TPS) for sensing the open status of the throttle valve; a stop lamp switch for sensing the braking status; an inhibitor switch for sensing the position of the automatic transmission; a rough road detecting algorithm wherein the data obtained from the each said element are inputted to the control unit, and the rough road detecting part of the said control unit decides the condition of the road surface by performing FFT of the inputted data, multiplying the established frequency gain, integrating and adding, when the front left wheel speed is below 40 KPH; and an anti-roll control algorithm wherein the transverse acceleration calculated using the left and right wheel speed difference is numerically differentiated, and the damping force becomes hard if the said transverse acceleration differentiation value is larger than the transverse acceleration differentiation threshold value, when the front left wheel speed is over 40 KPH.