Adaptive output feedback control for uncertain nonlinear systems with quantized input and output

In this paper, an adaptive stabilization control scheme is developed for uncertain nonlinear systems with both quantized input and output. Initially, a finite-time filter is introduced and applied to the discontinuous quantized output. It is shown that the output of the finite-time filter, named filtered quantized output, is continuous and adheres to the sector bound property. Subsequently, an observer is constructed to estimate unmeasurable states, followed by the design of a control scheme utilizing dynamic surface control technique, so as to avoid repeated derivatives of the filtered quantized output. Finally, it is demonstrated by theoretical analysis and simulation results that, even with coarse input and output quantizers, the stabilization error can be driven to a small residual set by adjusting certain design parameters.