RBF Fuzzy Adaptive Control Of Electro-hydraulic Velocity Servo System

Today electro-hydraulic servo system is widely used in the national defense area, aerospace area and the civil area, for it has the advantages of large power weight ratio, larger torque inertance ratio, fast response and high control concise and so on. With the development of science and technology, the performance demand for electro-hydraulic servo system is higher. Considering that the system is nonlinear and its parameters are uncertain, an accurate mathematical model is difficult to establish, so traditional PID control is hard to meet the control demand, in this aspect, intelligent control represented by fuzzy and neural network control has the superiority in nonlinear system.In this paper, intelligent control is applied to electro-hydraulic servo system, and more importance is attached to control method for the sake of proceeding real-time control. Seeking a feasible control method is useful to settle a practical problem.A conventional fuzzy controller is designed firstly according to the characteristics of the electro-hydraulic servo system. Though fuzzy controller has simple structure, nice robustness and fast follow-up, it is difficult to study by itself and it has low accuracy. While RBF(radial basis function) neural network control is also adapt to nonlinear system, and it has high accuracy, the self study ability and fast calculation. Thus combining the advantages of fuzzy and neural network control, a RBF fuzzy adaptive controller is designed on the basis of the interpretive structure of fuzzy controller. The parameters of fuzzy controller are modified continuously in the real-time control using RBF neural network self study ability, and then electro-hydraulic servo system is better controlled. Simulation is preceded one by one with the following control method, PID control, conventional fuzzy control and RBF fuzzy adaptive control. The simulation results prove the feasibility and validity of the RBF controller.