Distributed observer-based decentralised preview tracking control for a class of QOSL nonlinear interconnected systems

This paper investigates the observer-based decentralised preview control problem for continuous-time interconnected systems (ISs) characterised by quasi-one-sided Lipschitz (QOSL) and bounded Jacobian (BJ) nonlinearities. First, interconnected local state observers are synthesised by sharing estimated states to reconstruct unmeasurable subsystem states. By leveraging the differentiation and state-lifting techniques, local augmented error systems are formulated to explicitly incorporate future reference information. These local dynamics are subsequently aggregated into a global augmented error system, thereby transforming the tracking objective into a decentralised L2-gain control problem. Based on Lyapunov stability theory, sufficient conditions ensuring closed-loop asymptotic stability and a prescribed L2-gain performance level are derived. A one-step linear matrix inequality (LMI) procedure is developed to simultaneously determine the observer and controller gains, significantly reducing computational complexity. Finally, numerical simulations demonstrate the efficacy and advantages of the proposed observer-based decentralised preview control strategy.