Reasearch On Predictor Control Unit In The Controlsystem Of Twin-Screw Extruder

The fast development of modern micro-electronic and computer techniques brings about great change to traditional industrial production. "Electromechanical integration", as an intercrossing and interdisciplinary subject which is newly emerging, bears hopeful and far-raging prospect for application. The general application of industrial control unit advances many control technologies for traditional mechanical equipment to a new stage.The design of the predictor control unit in the control system of two-screw extruder in this subject, can input all the data into the computer through the communication interface, also can achieve the real time collection and control when the extruder's working .It is convenient for using the data as it can save the data directly to the disk.The project included the explanation of the control principle, the structure of the hardware, and the control mode. According to the principle of higher precision, higher reliability, the design finished the following work:(l)The main control unit is AT89C52 which was made in ATMEL company. The whole system realized the functions of data collecting, data keeping, temperature control, electromotor control, anti-jamming etc.(2)In the temperature control system, the temperature sensor is thermocouple of type E, use the AD590(temperature sensor) to measure the environmental temperature , as the compensation of cool-end of thermocouple. Adopted solid state relay (SSR) as the heater's switching component. The application of intelligent control and digital filter improves the precision of the measurement. The method of the governing speed of electromotor is to change the armature's voltage. If the voltage variety is smooth, the speed of electromotor changed smoothly. Applying the method there will be wide range of speed governing and lower power consumption.(3)The system adopts the combination of the fuzzy control and PID control as its control strategy. The experiment proved the system to have satisfying control effect.In the system, the design method of the temperature control system aims at the control object with larger inertia and lag, it can be transplanted to other control system with the controlled object having the similar characteristic; The control system of rotational speed is a whole industrial real time control system, it can be applied in several control system of rotational speed, it has equivalent referenced value in engineering application.