Position Control In Pneumatic Proportional Valve And Cylinder System Based On Fuzzy Control

Pneumatic technology is widely applied in industry more and more and is playing in an important role in automation field owing to the advantages of simple in structure, reliable in work, no pollution etc. However, the inherent characteristics of the pneumatic system, such as the compressibility of the air, nonlinear of valve, friction characteristic of pneumatic cylinder and easily influenced by environment factors etc, greatly increased the control difficulty in a degree, and hard to obtain satisfied performance of the pneumatic orientation control system. How to realize pneumatic system rapidly and accurately position control become important issue of Pneumatic proportion/servo control technology.The present Pneumatic Proportional Valve and Cylinder System is composed of 5/3 Proportional valve MPYE-5-1/4-010-B and rodless cylinder GP-25-400-PPV-A-B all made by FESTO. However, the present Pneumatic Proportional position control System responds slowly and does not work steadily for some characters of Pneumatic system.On the analysis of the characters of Proportional Valves and Rodless Cylinder, the math model of the system is established based on the analysis of the control system by the theories of Aerodynamics, continuity of mass law and Newton's Second Law. The influence of the changing of the system stability is analyzed. The system using traditional proportion and PID control is difficult to obtain favorable control effect simulation. Considering the characters such as non-linear, time dependence, wide range of parameter change, the large outer load interference in the liquid itself, and combining to the characters and suitable conditions of fuzzy control, the Pneumatic Proportional position control is controlled by fuzzy control.With the study of fuzzy control technology, we design the widely used and mature in theory planar fuzzy controller. With the study of MATLAB simulate, the traditional control is compared to the fuzzy control. Finally, we find that the fuzzy control could achieve the control requirement, and the feasibility and advantage of the fuzzy control is examed.