Finite-Time Fault-Tolerant Control for Swashplate of Integrated Hydraulic Transformer With Uncertain Mismatched Interference

The precision position control for the swashplate servomechanism of the integrated hydraulic transformer (IHT) with mismatched interference is considered in this article. Compared with the type of port-plate-rotating IHT, the swashplate-rotating IHT has smaller leakage and higher efficiency, but suffers from parameters uncertainty, and time-varying uncertain torque from the plungers. To enhance the robustness of the proposed system, a novel robust control scheme based on a finite-time extended state observer (FTESO) is developed. In the proposed control scheme, the system nonlinearities, parameter uncertainty, and actuator failure are taken into account, and a novel FTESO is established to obtain the state variables, load torque, and failure signals. By introducing the nonsingular terminal sliding mode surface and finite-time technique in each step of the backstepping design, the novel control scheme is able to enhance the robustness of servomechanism and realize finite-time stability of the tracking errors. Finally, the comparative experiment is performed to verify the effectiveness of the controller design.