Dual objective nonlinear PD sliding mode control based on an adaptive reference model for an active suspension system

Abstract

Abstract This article focuses on the study of nonlinear active suspension tracking control problems based on an adaptive reference model. To mitigate the drawback of compromised ride comfort caused by tracking errors while tracking the adaptive trajectory of body displacement, the paper explores a tracking controller with dual objectives. This includes a nonlinear PD controller for tracking the adaptive desired trajectory and a sliding mode controller concerning body velocity and acceleration. This approach ensures that the body displacement approximately tracks the desired trajectory while significantly improving ride comfort, additionally, this control method has the advantages of structural simplicity and insensitivity to tracking errors, implying that control parameters can be easily tuned, and control inputs can be effectively reduced. The stability of the controlled system is demonstrated through the Lyapunov stability theory, and a range for the body displacement tracking error is derived. Finally, the performance of the controller is tested on an experimental platform, with results indicating a substantial reduction of 69.22% and 54.66% in the RMS values of body acceleration under bump and random excitation, respectively.