Disturbance Rejection and Performance Improvement for Control Systems Using a Finite-Time Equivalent-Input-Disturbance Approach

This article presents a finite-time equivalent-input-disturbance (FTEID) approach that estimates the EID in a finite time. A finite-time state observer and a finite-time EID estimator ensure the finite-time convergence of the EID estimation and make improvement for the disturbance-rejection performance of a control system. The FTEID-based control system is divided into three subsystems for stability analysis and an algorithm is carried out to design gains of state feedback and finite-time observer. The effectiveness and superiority of the FTEID approach are verified by experiments of a Stewart-platform control system.