Development and implementation of fuzzy, fuzzy PID and LQR controllers for an roll-plane active Hydraulically Interconnected Suspension

A new active Hydraulically Interconnected Suspension (HIS) has been developed to compensate the limitations of conventional active suspensions such as expensive cost and high energy consumption. In this paper, the mechanism of proposed active HIS system has been briefly introduced. Fuzzy Logic Control, Fuzzy proportional-integral-derivative (PID) control and optimal linear quadratic regulator (LQR) theory have been adopted to control vehicle body's roll motion. A combination of a half-car model and the active suspension model is then derived through their mechanical-hydraulic coupling in the cylinders for the model based LQR control. Three controllers have been developed and implemented in Simulink. Two different road excitations have been used to validate the robustness of the designed controllers. The effectiveness of all these three controllers has been verified by the simulation results with considerable roll angle reductions, and the Fuzzy PID controller shows better effect and stability than other two controllers.