Study And Development Of Temperature Intelligent Monitor And Control System For Injecting Plastic Moulding

In this paper, for the demand for temperature during the process of injecting plastic moulding , studying and developing a temperature intelligent control system for injecting plastic moulding based on parameters self-adjusted PID arithmetic based on fuzzy inference. The main contents are: the measure circuit for injecting plastic moulding machine , double integral serial A/D conversion circuit, the powercombined multi-channels PWM power adjuster, fuzzy PID controller, the interface for human and computer and so on. The whole system adopts distributing structure. Single-chip micro controllers are adopted in the modern control and data-collection system to dominate on-the-spot operation. The powerful PC with its friendly interface serves as the back-stage of the system. The PC and the single chip micro controllers are connected through RS-485 bus.Each local machine consists of two single chip micro controllers, AT89C52 is used to be main control chip to realize parameters self-adjusted PID arithmetic based on fuzzy inference , data collection and serial communication with computer; Single-chip micro controller AT89C2051 is used to produce PWM signal to control the switch of the relay.In upper machine module, with ActiveX technique MSComm in Visual C++ 6.0 programming under Microsoft Windows platform, PC realizes serial port asynchronous communication with single chip micro controllers.