Electro-hydraulic Load Simulator Control Method Study

Electro-hydraulic servo system is a typical couple system of mechanics and electro-hydraulic, which has the characteristic of nonlinearity, parameter uncertainties, loading disturbances and etc. Compared with generic control system, it's more complex to design the controller of electro-hydraulic servo system. Electro-hydraulic loading simulator is a passive electro-hydraulic torque servo system, which is used to simulate dynamic air power torque of the aircraft rudder under laboratory conditions, so as to detect technical performance index of the rudder driving system. It not only possesses the characteristic of the common electro-hydraulic servo system, but also has the characteristic of movement disturbance, so its controller design is more difficult. Studying its advanced control method not only is important for the development of higher performance electro-hydraulic loading simulator and electro-hydraulic servo system control method, but also promotes the development of control theory. This paper is originated from several practical projects, and mainly studies the advanced control method of electro-hydraulic loading simulator.This paper first analyzes the basic structure and principle of the electro-hydraulic loading simulator, next establishes the linear mathematical model, then analyzes the system's static and dynamic performance, mechanism and characteristics of surplus torque, finally reveals the effect of system structure parameters (such as inertia, connect rigidity etc) and the impedance of rudder driving system for loading simulator performance. These analyses provide the theory reference for the design of loading simulator and its controller.After deeply research on linear control strategy which widely applies in practical projects, the control method which uses feed-forward compensation to eliminate the surplus torque is analyzed detailed. Then, PID controller, cascade compensation and feed-forward compensation are combined together to design the synthetical controller of loading simulator. The simulation and experimentation results indicate that synthetical controller proposed in this paper effectively improved the static and dynamic performance of loading simulator.Nonlinearity and uncertainties are the key factors that influence the further improvement of system performance. This paper proposes two nonlinear robust adaptive controllers for unmatched uncertainties system. Firstly, after comparison of exact feedback linearization technology with GCMAC neural network, a robust...