Filter-based robust model-free adaptive funnel control for discrete-time nonlinear systems with jumped reference signal

This article proposes a filter-based robust model-free adaptive funnel control for discrete-time nonlinear systems with measurement noise and jumped reference signal. To suppress the effects of measurement noise on the estimated dynamic linearized model, a robust projection algorithm with filtered output is designed to estimate the pseudo-partial derivative vector. Based on this estimated model, a novel discrete-time funnel function-based switching sliding-mode surface is proposed to cope with the problem of the jumped reference signal. A time-varying weighting factor-based cost function is proposed in the controller design to reduce the control consumption whenever the tracking error exceeds the actual performance funnel, and the time-varying weighting factor is tuned by a designed event-triggered mechanism. Furthermore, the performance margin, tolerable uncertainties, and parameter selections have been analyzed in detail. Simulations and experimental results verify the effectiveness of the proposed robust control strategy.