Semi-Active Control Methodology for Control of Air Spring-Valve-Accumulator System

This paper presents a semi-active control methodology for controlling the vibration of a pneumatic air spring-valve-accumulator system. Three controllers are presented and compared, along with experimental results. Due to the semi-active nature of this system, each controller uses a skyhook switching algorithm, along with a set-point plus PI tracking algorithm to track a desired reference signal. Some combination of pressure and displacement (or relative displacement) sensor feedback is used in each case. The desired reference control signal is generated by three different methods. The first method uses an optimal LQI (Linear Quadratic Impulse) controller generated from Covariance Control Theory. The second method uses a modified skyhook algorithm, and the third method uses a command directly proportional to the relative displacement. The second two methods use the first method (LQI) to tune the required controller gains off-line.