Research On Data Collecting System And Fuzzy Control Foundation For Liquid-Solid Extrusion

Liquid-solid extrusion process for composite materials is a new technology developed recently. It is very promising due to its simple procedure and less cost. However, the whole forming process which include infiltration, solidification and plastic deformation is quite complicated. This thesis targets to apply the data collecting system and computer automatic control to the process, so as to deepen the understanding of the law of process parameter change, and automatize the process and lay a base for its open application.According to the character of liquid-solid extrusion process for composite materials, a data collecting system for the process has been created, which facilitate the further research on the laws of liquid-solid extrusion of composite materials, the optimization of the process parameters and the fuzzy control. Experiments have proved its applicability and precision.By analyzing the experimental procedure curve, it is found that during the extrusion not only the extruding pressure will become higher for forming period, but it can also decline if the different process parameters are adopted. This testifies that the substance of the process is complex.Based on the electronic principle of hydraulic press, a computer switching control system has been developed, which has improved the adaptability of hydraulic press in the experiment of the liquid-solid extrusion process of composite materials.With the hydraulic press as the actuator, we designed a computer analogue control system by closed-loop electro hydraulic proportional valve to the moving speed of sliding block of the hydraulic press, which lays a foundation for the further key parameter control.Aiming at the forming speed control, a general mathematical model has been set up. According to the model, the experiment using MATLAB to simulate the process of tube product extrusion showed a very good result.On the basis of the above research, author brought forth an idea to the unite FEM, ANN knowledge and fuzzy control for the fuzzy control system model in liquid-solid extrusion of composite materials. At the same time, a visualized application software on the Windows standard for data collection and switching control is programmed to carry out data collecting, data displaying, data querying, curve dynamic displaying and switching control, which is accord with the software developing trend and facilitates the application of the data collecting system in the process and lays a foundation for the fuzzy control software design in the future.