Improving the performance of UDE-based controller using a new filter design

Abstract

Robust control of uncertain systems has been a field of active research and the technique of uncertainty and disturbance estimator (UDE) has proved itself as a viable tool in the design of a robust control strategy for systems having uncertainties and acted upon by disturbances. Though the technique is quite efficient for ensuring robustness under slow-varying disturbances, the presence of steady-state tracking and estimation errors cannot be ruled out for fast-varying or sinusoidal disturbances. To address this issue, a new form of filter in UDE-based controller is proposed in this work and it is shown that the errors can be kept within acceptable limits by means of appropriate choice of the design parameter $$\alpha $$ . Closed-loop stability and simulation results for wing-rock motion control problem employing an UDE-based controller using the new filter are carried out to demonstrate its efficacy against fast-varying uncertainties and disturbances.