Research On Opening And Closing Process Of Injection Molding Machine Based Fuzzy Controller With Varialble Universe

Plastic products as new industrial materials is more and more widely used in industry,and injection molding machine is an important tool to make and ensure quality plastic products.Therefore,the trend performance of injection molding machine need more rapid and steady,especially in the rapidly developing status of rapid injection molding machine.Opening and closing process as an important aspect of injection molding cycle play a crucial role in making the quality plastic products.Improving the control accuracy of control system is the key to prevent the phenomena of lacking clamping force or the mechanical shock which caused by the inaccurate position of opening and closing equipment.Fisrtly,the research and current status of the control system about opening and closing device at domestic and overseas was stated in this paper,then the reason of the inaccurate position system and mechanical structure was analyzed,for the above statement this paper improved fuzyy-PID control method with variable universe,and state the application of method in control system.Secondly,this paper improved the hydraulic circuit for the oscillation of opening and closing device,and servo-system was refit in the system.In order to improve the control accuracy and form the closed-loop control system,electronic ruler was replaced by the gratingruler.Thirdly,valve-controlled asymmetric cylinder was used in the hydraulic control system to prevent the pressure jump phenomenon,and equations were established based on the flow linearization equation of valve,flow continuity equation of hydraulic cylinder and load function.Fourth,structure principle and control algorithm were compared between traditional PID,fuzzy-PID and fuzzy-PID with variable universe controler.In order to deal with the problem in the condition that traditional PID controler faced the uncertain factors and fuzzy-PID controler coun't gain the higher control accuracy,this paper used variable universe to improve fuzzy-PID controler.Then,the system was simulated with mathematic model gained from third chapter and fuzzy-PID with variable universe controler designed.Steady-state performance and following performance was observed under step signal and sinusoidal signal.The simulation result turned that fuzzy-PID with variable universe controler showed good performance in the ablitly of adjusting time,control accuracy and anti-interference than other two controler.And it also showed the better ability in following varying speed under sinusoidal signal.At last,the interface of working conditions was exploited by C#,and soft was tested by simulated data.It was turned out that program runed well.Besides,the look-up table of fuzzy control regulations was established by PLC,system can gain parameters fastly without calculating so that program can obtain higher control accuracy.This paper improved the application fields of fuzzy-PID controler with variable universe which was applied to the hydraulic control system of injection molding machine.The simulation of this controler showed that this design could improve the control accuracy effectively which provided the guidance for the higher accuracy of rapid injection molding machine's development.