Fixed-Time Disturbance Observer-Based Control for Uncertainty Systems Applied to Permanent-Magnet Speed Control

For a class of uncertain systems, a fixed-time disturbance observer is suggested. The proposed observer not only estimated the disturbance but also ensured the fixed-time convergence, leading to the increased accuracy of the disturbance estimation together with the improved estimation speed. Taking the proposed observer in combination with a state-feedback controller and employing it in a fully actuated system, stabilization of the closed-loop system will be assured which allows the control of uncertain systems. With a numerical example to illustrate the efficacy of the scheme, finally, such scheme is successfully applied to the permanent-magnet speed control system, the results show that it has the advantages of rapid convergence speed and favorable control performance.