Suspension control system for automotive vehicle

摘要

A system is for controlling a suspension performance detecting the road surface condition in front of an automotive vehicle. A road surface sensor generates an output corresponding to the size of roughness on a road surface located at a predetermined distance in front of the vehicle. A suspension damping coefficient is changed to a smaller value upon lapse of a delay time. The delay time is calculated on the basis of the output of a speed sensor, the delay time being the time required for the wheel to reach the detected rough roads surface. The changing of the suspension damping coefficient occurs on condition that the output of the road surface sensor falls within a control region defined by a lower threshold value and an upper threshold value. Accordingly, the change of the suspension damping coefficient to a smaller value is inhibited when an extremely rough road surface is detected in front of the vehicle, whereby a bottoming out of the suspension which may occur is prevented when the vehicle runs over the extremely rough road surface. Further, the ride feeling is improved when the vehicle runs over a moderately rough road surface.