Study On The Method Of Electeo-hydraulic Servo Control Based On Sliding Mode Control Theory

Electro-hydraulic servo control system is an important branch of hydraulic field, and an important component of control technology. In recent years, electro-hydraulic servo control system has been paid more and more attention, especially in the military, aviation and other important scientific and technical sectors. Simulation analysis is undoubtedly the most effective method to meet the increasing technical requirements of modern science and technology on hydraulic servo control.In the actual production, electro-hydraulic servo system working environment is complex, its parameters are easy to change and the uncertainties of external disturbances are high, which contribute electro-hydraulic servo control system to be a typical nonlinear control system. It is hardly possible for traditional PID controllers to meet the requirements of control accuracy and response speed. In order to overcome the influence of this negative factor on electro-hydraulic position control system, more and more scholars have begun to pay attention to the controller study. As sliding mode control algorithm has characteristics of the control object parameters unrelated to external disturbance, the sliding mode control strategy has fast response, not sensitive to the control system parameter change and external disturbance change, no online identification and simple physical implementation. The sliding mode control has received various countries' scholars widely to design many kinds of slip form controllers to satisfy the different control system request, such as adaptive sliding mode controllers, neural sliding mode controllers, and so on. In view of this, this paper introduces the research on a control strategy used in the electro-hydraulic servo position control, and takes advantage of simulation results to analyze the feasibility and effectiveness of the control strategy.This paper, taking valve-controlled hydraulic cylinder position servo system as the research object, establishes the mathematical model for the working principle of hydraulic servo control through Matlab/Simulink software. Offline simulation study has been done on the system without load or disturbance, and the system with external disturbance, respectively applying traditional PID control strategy and the exponential reaching control strategy, theoretically verifying the feasibility of sliding mode control algorithm for hydraulic servo position control system.Because the Matlab/Simulink platform provides the mathematical model simulation, its results often have deviation beyond actual. Using components of hydraulic in AMESim software library to establish servo position control system physical model, it carries on the AMESim/Simulink control system union simulation. Analysis has been made on the result of the control system with outside disturbance force, verifying the robustness of sliding mode control strategy.Finally, the experimental confirmation is carried on in the semi-physical simulation platform, further verifying the correctness and feasibility of the sliding mode control strategy in hydraulic servo position control algorithm.