Observer-Based Adaptive Fuzzy Controller for Pneumatic Active Suspension with Displacement Constraint and Actuator Failures

In this study, an observer-based adaptive fuzzy controller is proposed for a quarter pneumatic active suspension considering the actuator failure and unknown dead zone of the air spring. To approximate the uncertain parameters, unmodeled dynamics, and unknown masses of passengers, fuzzy logic systems are employed. Besides, the system states are considered unmeasurable as the real suspension application which affects the control performance. To solve this problem, a fuzzy state observer is proposed to estimate the system states for the control design. Then, an adaptive command filtered control is developed to compensate for the effect of actuator imperfections and induce the issue of complexity problem. Furthermore, the tracking error of chassis movement is ensured by the prescribed performance. The system stability is analyzed by the Lyapunov theorem. Finally, the effectiveness of the designed control is justified by numerical simulation examples.