Decentralized output-feedback control of triangular large-scale nonlinear impulsive systems with time-varying delays: a gain scaling approach

In this study, we investigate the decentralized output-feedback control problem for a class of triangular large-scale nonlinear impulsive systems (TLSNISs) with time-varying delays. Unlike existing design approaches in impulsive systems, a gain scaling approach is proposed for the first time to counteract the structural uncertainties of interconnected nonlinearities. Specifically, by fully exploiting the static gain, novel delay-independent impulsive observers are delicately constructed to estimate the unavailable states. Furthermore, the undesirable effects of time-varying delays and impulsive disturbances are eliminated using the comparison principle and average impulsive interval technique. The designed gain-scaling-based decentralized output-feedback controllers have concise linear-like forms and are independent of time delays. Moreover, by strengthening the gain scaling mechanism, we further develop an improved control scheme that endows the controllers with the capability to tolerate unknown external disturbances, thus improving its robustness. It is shown that the system states converge exponentially to the origin in the disturbance-free case with the designed controllers (or to an adjustable neighborhood of the origin in the presence of disturbance). Finally, two examples, including an engineering system design example, are provided to demonstrate the effectiveness of the designed controllers for both lower TLSNISs and upper TLSNISs.