This paper focuses on the fast finite-time and high accuracy control issue of electro-hydraulic systems (EHS). A third-order mathematical dynamic model of EHS with parametric uncertainty and external load disturbance is provided at first. Then, a feedback linearization transversion via Lie derivative for EHS is manipulated to overcome the nonlinear part in the nonlinear EHS model, which reduce the difficulty of controller design process since the nonlinear part of the EHS system can be unconsidered. A kind of disturbance observer is constructed for linearized EHS model via sliding mode disturbance observer to compensate the lumped uncertainty unavoidable in the system, based on which a finite-time sliding mode position tracking control strategy is designed for EHS, which realize the fast finite-time tracking control purpose of EHS. The feasibility of the theoretical results in this paper are verified by simulation and experiment, which illustrate that the feedback linearization transversion via Lie derivative can effectively reduce the negative impact of the nonlinear part of the EHS model, the proposed disturbance observer can effectively estimate the lumped uncertainties and raised the control accuracy and the controller designed in this paper can accelerate the tracking performance of EHS.

This article focuses on the high accuracy quasi-synchronous control issue of multiple electrohydraulic systems (MEHS). In order to overcome the negative effects of parameter uncertainty and external load interference of MEHS, a kind of finite-time disturbance observer (FTDO) via terminal sliding mode method is constructed based on the MEHS model to achieve fast and accuracy estimation and compensation ability. To avoid the differential explosion in backstepping iteration, the dynamic surface control is used in this paper to guarantee the follower electrohydraulic nodes synchronize to the leader motion with a better performance. Furthermore, a time-varying barrier Lyapunov function (tvBLF) is adopted during the controller design process to constraint the output tracking error of MEHS in a prescribed performance with time-varying exponential function. As the initial state condition is relax by tvBLF, the input saturation law is also adopted during the controller design process in this paper to restrain the surges of input signals, which can avoid the circuit and mechanical structure damage caused by the volatile input signal. An MEHS experimental bench is constructed to verify the effectiveness of the theoretical conclusions proposed in this paper and the advantages of the proposed conclusions in this paper are illustrated by a series of contradistinctive experimental results.