Output Feedback Robust Tracking Control for a Variable-Speed Pump-Controlled Hydraulic System Subject to Mismatched Uncertainties

In this paper, a novel simple, but effective output feedback robust control (OFRC) for achieving highly accurate position tracking of pump-controlled electro-hydraulic system is presented. To cope with the unavailability all state information, an extended observer (ESO) was adopted to estimate angular velocity and load-pressure-related variable actuator total matched disturbance, which enters through same channel as input in dynamics. addition, first time, another ESO acting disturbance (DOB) skillfully integrated effectively compensate adverse effects lumped mismatched uncertainty caused by parameter perturbation external loads Then, dynamic surface-control-based backstepping controller (DSC-BC) based on constructed ESOs studied synthesized guarantee that closely tracks desired trajectory avoid inherent computational burden conventional method because repetitive analytical derivative calculation at each iteration. Furthermore, stability two observes overall closed-loop verified using Lyapunov theory. Finally, several extensive comparative experiments were carried out demonstrate advantage recommended approach comparison some reference methods.