Abstract
In this paper a new control algorithm based on the monotonic performance sequence concept for effective control of a multi-stage semi-active variable damper system of a passenger car is proposed. The algorithm extends the Sky-hook control algorithm and selects a sequence of ordered pairs constructed by combinations of damping stages that have relatively hard and soft damping characteristics. The sequence has monotonic property in the performance indices related to ride comfort and driving safety. Simulation on a semi-active damper system with damping force level variation and actuator response time is performed with a quarter-car simulation model which is verified through tests on a quarter-car test rig. With the simulation results, possibility of applicability of the proposed control algorithm to the practical control of a multi-stage semi-active variable damper system is discussed.