Abstract: This article describes a typical architecture of electro-hydrostatic actuator (EHA), and establishes its nonlinear accuracy model by block diagram, which contains the refeeding circuit and friction. Based on the simulation analysis of damping, static error and friction, this article utilizes the dynamic pressure feedback and gain variable strategy to design the controller in state space. The robusttest results indicate the influence of parametric uncertainness on system performance.

Key words: electro-hydrostatic actuator, block diagram model, simulation, control, robustness