3 SEMI-ACTIVE CONTROL OF A HALF-CAR
MODEL
It has been suggested that a damper-controlled variable-spring-stiffness suspension can replace the conventional passive suspension. In this suspension, the parameters are under control. In other words, the parameters are changed continuously in a slow or rapid fashion. Such a system is called semi-active because only a low level of power is required. Another method to improve the ride quality is the use of optimal control theory.
Semi-active control can be achieved by two methods:
(a) using force generators;
(b) using actuators