The Application Of Sliding Model Control In The Pneumatic Position Servo System

Pneumatic technology has a series of obvious advantages such as low cost, simple construction, reliable in work, no air pollution. So it is applied widely in industry more and more,and becomes an important method of automation.However, the inherent characteristics of the pneumatic system, such as the condensability of the air, friction characteristic of pneumatic cylinder, nonlinear of valve and easily influenced by environment factors, greatly increased the control difficulty in a degree, and is hard to satisfy the orientation request in industry."The application of sliding model control in the pneumatic position servo control system"is part of the international cooperation programs in SMC–SJTU technology Center .The goal is to further the development of a high-precision positioning system,and lay out the performance of the pneumatic components, for the course of control theory for undergraduate as well.A common pneumatic cylinder, MQQTB16-50D of SMC company,is selected as the actuator, but it's difficult to carry out servo control because of its serious nonlinear friction and unsymmetrical.In this article, a nonlinear mathematics model is built, as well as friction cylinder nonlinear mathematical model. We simulate in Matlab / Simulink environment with sliding model control and fuzzy sliding model control, under the condition of friction. The simulation results show that, FSMC method can has better dynamic characteristics, and control effect.Before experiment, we solve the straight cylinder position servo system dead-Determination and correction, gain unsymmetrical value of K in the revised domain and state feedback. The simulation results in Matlab / Simulink under the RTW HWIL show that Fuzzy sliding model controller can reach the sliding surface quickly and weaken jitter effectively. And the controller shows robust when external conditions change, such as the load changes, the changes in gas pressure, different positioning location and also.Finally, the work of this study is summarized, and some suggestions and expectations are put forward for further research.