Prescribed-time output stabilization for mismatched uncertain systems using state-feedback control based on extended disturbance observer

This paper presents a prescribed-time output stabilization method for mismatched uncertain systems using state-feedback control and extended disturbance compensation. The settling-time interval is divided into a disturbance-estimation interval plus an output-stabilization interval, where a prescribed-time extended disturbance observer with finite time-varying gains (PTFG-EDO) and a modified time–space deformation approach (TSDA) control are applied in these intervals, respectively. Due to the prescribed-time convergence of the PTFG-EDO and the modified TSDA control, the settling time of the closed-loop system can be predetermined irrespective of the initial conditions, design parameters, and admissible disturbances. The chattering problem of the original TSDA control is greatly alleviated, and the disturbances, especially the mismatched disturbance which cannot be handled in the original TSDA control, are significantly suppressed. The effectiveness of the proposed PTFG-EDO-based control is demonstrated via numerical simulations.