Cylinder Cache Control System

Pneumatic control technique has been widely used in manufacture and become an important method of automation due to its unique advantages. Modern product line requires pneumatic system to have heavier load, higher speed and longer life. So the cushioning of the actuator is becoming more important. This thesis deeply researches on cushioning control strategy of the pneumatic cushioning control system. The whole thesis consists of six sections:Chapter 1 first briefly states the pneumatic technique feature, the current application situation and the foreground of pneumatic control technique. Then it introduces the developing-history and current application situation of pneumatic cushioning methods. In the end this chapter points out the main content of the research work, especially introduces the electropneumtic proportional/servo control theory and application.Chapter 2 deduces the mathematical model of electropneumtic proportional /servo cushioning controlled system by theoretical analysis. Because of the essential nonlinear characteristic of electropneumtic proportional/servo control system, the three orders model is validated right by system identification method. This result provide base for the controller design.Chapter 3 firstly introduces the hardware structure design of the control system which including pneumatic part and computer control part. Then a control strategy research platform based on MATLAB software is presented. Because of using a lot of resources and integrating analyse, simulation and real-time control, the efficiency of research is improved greatly. In the end this chapter a real-time control software programmed by author is presented. User can chang it freely. The signals sampled on hardware interrupt assure the real-time property and control reliability.Chapter 4 first analyzes the basic characteristics of electropneumtic proportional /servo cushioning controlled system, especial study the influence of the valve dead zone, system friction and saturation phenomenon. After that this chapter discusses three ways that gets system state (differential+filter, two kinds of state observer, pressure sensor) and compare with each other. At last this chapter researches two ways that make system performance optimal, test way and pole allocation way. The affections of feedback parameters, air pressure and load quality are analyzed.Chapter 5 introduces the theory, application and foreground of the VSC (variablestructure control) system. Then a VSC controller using ON-OFF valve and two potentiometers are designed for cushioning control system. It can realize the balanced, no shock, no reversing cushioning. Experiments under different air pressure, load mass are carried out, and the results prove that the VSC controller can be used in pneumatic cushioning. It has good performance and robustness property. Chapter 6 summarizes the paper.