Integrated variable speed-fuzzy PWM control for ride height adjustment of active air suspension systems

This paper focuses on the ride height (RH) adjustment of an active air suspension on the basis of a variable speed-fuzzy PWM control method. Firstly, an active air suspension (AAS) system, which consists of an inflatable air spring (IAS) model and a hydraulic damper model, is constructed. Then, a fuzzy control method is integrated with the pulse width modulation (PWM) method to realize the RH adjustment. Moreover, a Proportion Integration Differentiation (PID) tuning method is employed to fasten the speed of the air charging and discharging operation of the IAS model. To further solve the conflicts between the ride comfort and the road holding capacity, a sliding mode control (SMC) is utilized for the hydraulic damper. Numerical results show that, the RH adjustment under static and dynamic situation are well performed with the proposed method. In addition, the compromise between the ride comfort and road holding capacity is also satisfied with the SMC control algorithm.