Disturbance-observer-based adaptive command filtered control for uncertain nonlinear systems

This article proposes an asymptotic adaptive command filtered control approach for uncertain non-linear systems with parametric uncertainties, mismatched and matched disturbances. To accomplish the task, a disturbance observer (DO) only with one tuning parameter is firstly used to attain the disturbance compensation. The parameter uncertainties can be addressed via composite updated laws. Then, by judiciously combining DO, adaptive control and command filter technique, a novel command filtered controller with adaptive-gain auxiliary systems is developed to attain asymptotic tracking and shun "explosion of complexity". The system stability is proved by utilizing the Lyapunov function. Extensive experimental results uncover the preponderance of the exhibited strategy.(c) 2022 ISA. Published by Elsevier Ltd. All rights reserved.