Development Of The Flexible Positioning Pneumatic Manipulator Based On The Common Cylinder Controlled By The Pneumatic Proportional Valve

Pneumatic system has a lot of advantages such as clean,low-cost,simple structure,easy to operate,and it is widely used in industry field.Now,with the emergence of the electric-pneumatic-servo control technology,pneumatic system is extended from logical control to servo control.The research of the pneumatic servo control system is developed from point-to-point positioning control to continuous trajectory tracking control.The main research object of the project is a single-rod double-acting common pneumatic cylinder,but it's more difficult to carry out servo control because of its serious nonlinear friction and unsymmetry.According to these characters,this paper designs high quality controllers to focus on both point-to-point positioning and continuous trajectory tracking control.On this base,realize the development of the flexible positioning pneumatic manipulator based on the common cylinder controlled by the pneumatic proportional valve.The main contents are shown as follows:Firstly,establish the experimental test platform.The mathematic model is established on the base of careful analysis of characters and principle of the system. The model shows that the system is a high-level non-linear system,so the model is simplified in this paper and a third-order mathematical model is got.Stability is one of the basic requirements of the control system,and in this paper,the stability of the control system is judged by MATLAB control toolbox.The results show that the system is unstable.Secondly,A PID controller is designed for the system,and a Fuzzy controller that tracks step,square and sinusoidal signal is established by the Matlab fuzzy toolbox.In view of the convenience and fast of the graphical programming language,the control program is written by Lab view and MATLAB.During the experiments of responding the step signal,square wave signal and sine signal,disadvantages of the PID controller is found in this nonlinear system and is improved.But generally,the error is still big and the system stablity is bad.A mass of experiments are carried out using Fuzzy control strategy,the results show that there is no slipping oscillation of step response,the square wave response is stable,the precision of sine wave response in a certain frequency bound is improved and the adaptive ability is enhanced.So the fuzzy controller is stable and effective.Then,the pneumatic manipulator that can crawl,transport and change tool is designed with the application of the pnumatic theory and the PID controller and fuzzy controller are applied to the pneumatic manipulator,so the pneumatic manipulator can be positioned flexible in the horizontal direction,and the preparation is made for its application.Finally,for the shortages and disadvantages still existing in this study,some suggestions and expectations are put forward for further research.