System and method for controlling damping force characteristic of shock absorber applicable to automotive suspension

摘要

A system and method for controlling a damper of vehicular suspension in which when the vehicle runs on a paved road and a frequency at which the detected sprung mass acceleration exceeds a dead zone is below a set value, the damping force characteristic is optimally controlled in a predetermined variable range. When the vehicle runs on a rough road and a frequency at which the detected acceleration exceeds the dead zone is above the set value, a minimum damping force limit of the predetermined variable range of the damping force characteristic is shifted toward a relatively high damping force side, The dead zone is set with an average value of the acceleration of sprung mass as a center. Hence, when the vehicle turns and zigzags, the vehicular body is inclined so that an absolute value of the sprung mass acceleration is largely changed. In this case, when an average value of the acceleration of the sprung mass is accordingly changed and the dead zone is accordingly shifted. Thus, the frequency at which the sprung mass acceleration exceeds the dead zone accurately corresponds to a situation on a road surface and the damping force characteristic is accurately controlled according to the road surface condition.