Sampled-Data Output Feedback Control for an Active Suspension System Under Transmission Delay and Time-Varying Loads

Modern control systems in the automotive industry aim to improve ride comfort and handling performance. In this context, non-uniform sampling, transmission delay, and partial measurements in states are increasingly important features to consider. This paper presents design conditions formulated via linear matrix inequalities (LMIs) for an output feedback controller that considers both non-uniform sampling and time delay in the state transmission. Moreover, for a more realistic setting, we consider a time-varying vehicle load. To address these challenges, the active suspension system (ASS) will be modeled as a Takagi-Sugeno (T-S) fuzzy system, and an augmented Lyapunov functional is proposed. This functional also includes information from the membership functions (MFs), allows the design conditions to be relaxed. First, we propose a state feedback control, consequently, we derive the desired static output feedback (SOF) control design conditions. Simulations and practical results are presented to demonstrate the effectiveness of the proposed controller.