ACTIVE SUSPENSION SYSTEM OF VEHICLE

摘要

An active suspension system of an automotive vehicle having four air suspension units for four wheels has a first sensor for detecting vertical acceleration of the mass above each suspension unit spring, a second sensor for detecting the vertical relative displacement of the masses above and below each unit spring, a controller for operating in response to the output signals from the two sensors and a relative displacement velocity signal obtained by differentiation of the signal from the second sensor to generate an instruction air flow quantity signal, and a control valve operating in response to this flow quantity signal from each controller to control the charging or discharging of air into or from each unit. An auxiliary damper is provided in each unit to damp vibrations of relatively high frequencies. A low-pass filter is used to filter off a relatively high-frequency component of the output signal of at least the first sensor, whereby vibrations of relatively low frequencies are damped and absorbed by the operation of the air spring action of each unit according to the operation of the control valve.