The Study Of The Wood-based Panels' Continual Hot-press Control System Based On PLC

During the production of man-made fiber board, hot-pressing is one of the crucial working procedures. It has a decisive effect on products' quality and output. Temperature, pressure and time are the main factors of hot-pressing process, which can prepare a certain density fiberboard through controlling the process parameters reasonably. The control of hot-pressing panel of continuous-pressing machine is the main component of production line control system. It is also important for the entire line to reach uninterrupted and entire automatic production. So it is of a great practical significance to the hot press control system research.The article takes hot press control system to be research object, on the theory basic of hot press technology factors control principle, takes panel continuous pressing machine as control object, takes various sensors as various simulation data signal detection device, takes Omron Controller Link network as communications path, and takes industrial compute and PLC consisting of upper and lower body structure as industrial structure, then establish a hot-pressing control system to achieve the functions contain data acquisition, process control and remote monitoring. It accords the input and output points to complete PLC system hardware configuration. By according to the structural characteristics of continuous pressing machine and hot-pressing control principle, with Omron PLC programming CX-Programmer compose the control program of the hot-pressing process's parameters control requirements, which contains pressing pressure, temperature and speed of hot pressing plate spacing press. With King View6.03configuration, designs human and machine interface to read the detective result data of the spots of PLC.Pressure control system is a kind of nonlinear and time-delay system, which is unable to establish a precise mathematical model, but the pressure control in the production process requires high precision, and it is greatly affected by other technical factors. Then with PLC and fuzzy self-setting PID parameter controller formed by fuzzy control and PID control algorithm, optimizes the pressure control system of wood-based panel continuous pressing. Fuzzy PID is a control method through using control table made by expert's experience to adjust the three PID parameters. It avoids the shortages of receiving good quality dynamic and static accuracy because it is difficult to define parameters of normal PID control. And it also solves control problem of being unable to construct mathematics model with control objects. The optimizing system makes pressure control reach the requirements of the control accurate.