Pressing Machine Control System Design And Implementation

This paper gives a full picture of control system of hot-press by introducing its design and accomplishment.Hot-press is a device of industrial manufacture designed to heat and press the workpieces. We designed this control system to fit the hot-press. Its center unit is 89C55 single-chip microcontroller, and its output interface is a color LCD (Liquid Crystal Display). It can automatically run in line with technical parameters, and at the same time show the operating curve and varieties of operating condition. This control system has friendly user interface, simple operating method of menu choice, and visualized method to establish technical data. It can warn and process all kinds of abnormal condition in the working procedure.This paper describes the designing principle and method of hardware and software of this system, especially discusses the precise control of the temperature and pressure in theory. We adopted the new method of intelligent PID parameters auto-tuning--relaying PID auto-tuning. This kind of parameters auto-tuning technique fully abandons the operation of modeling and sub-modeling, and directly tune the parameters by investigating the close-loop capacity. It uses method of integration separation in PID control of temperature. As for pressure, it uses advanced PI control method. Seen from the comparing result of theoretical and actual curves, the control of temperature and pressure is quite quick and precise, and it is popular with consumers.