Extended Sliding Mode Disturbance Observer-Based Error- Driven adaptive robust feedback Control of Uncertain Nonlinear Systems: theory and application

In this paper, an error-driven adaptive robust feedback control with an extended sliding mode disturbance observer (ARCESO) has been developed for uncertain nonlinear systems with parametric uncertainties and uncertain nonlinearities. To address the uncertainties arising from parametric deviations and external disturbances, the parameter adaptation mechanism is incorporated into the extended sliding mode disturbance observer (ESMOO) design to estimates of both the unmeasurable signal and uncertain nonlinearities, which has better transient behavior of the estimations. An improved error-driven nonlinear functions are constructed with feedback gain self-regulates to avoid the high gain chattering of the closed loop system. The salient feature is that control performance, parametric deviations and uncertain nonlinearities as well as output feedback difficulties can be comprehensively handled with acceptable control performance. The motion control of a motor-driven robot manipulator is investigated as an application example and comparative simulation results are obtained to verify the benefits and effectiveness of the proposed control strategy.