Model-free fractional-order sliding mode control for an active vehicle suspension system

This paper presents a new model-free fractional-order sliding mode control (MFFOSMC) based on an Extended State Observer (ESO) for a quarter car active suspension systems. The main goal is to increase the ride comfort while the dynamic wheel load and the suspension deflection remain within safety critical bounds. The model with nonlinearity, parameter variation and/or external disturbance which includes the friction force effect are simultaneously considered to provide a realistic framework. Moreover, modeling was performed using the software LMS AMESim, while the control part was configured on Matlab/Simulink. Lyapunov stability theory is used to analyze the closed-loop system and finite-time convergence stability. Finally, to demonstrate the effectiveness of the proposed controller, a comparison with classical PID, time delay estimation control, and intelligent PID controller has been performed.