This study investigates an improved observer-based position tracking control framework for robot manipulators (RM) operating under uncertainties and sudden variations in the control environment. An adaptive velocity observer is incorporated into the control design to estimate joint velocities without requiring direct velocity measurements. To enhance adaptability and robustness, adaptive estimation and self-updating algorithms are developed for both the observer gains and the control gains, allowing the proposed scheme to accommodate unknown dynamics and time-varying disturbances. In addition, a compensator-typed robust term is introduced to mitigate the effects of inevitable estimation and updating errors. The stability and tracking performance of the overall observer-based control system are rigorously guaranteed via Lyapunov-based analysis. Comparative simulation studies under abrupt environmental changes and external disturbances demonstrate that the proposed approach achieves effective and reliable tracking performance when compared with related observer-based and robust control methods.
Long et al. (Thu,) studied this question.