2023.01.09
Foam plastics are widely used in production and life. Foam molding machines are important equipment in the plastic industry. However, at present, the production level of this industry in our country is low, the technology is poor, and the automation level is not high. The pressure control system of the foam molding machine before the improvement adopts the traditional switch control. Although this method is simple and easy to implement, the pressure control of the steam is extremely unstable, the response speed is slow, and the noise is large; the products produced Overall poor quality. Aiming at the problem of insufficient control accuracy and stability of the steam pressure of the foam molding machine in the product molding process, the control system of the foam molding machine has been technically improved to achieve higher automation of the production process and better man-machine communication . The system before technical improvement is analyzed, and the fuzzy PID control method is proposed to better meet the system requirements. The whole control system takes PLC as the core, realizes the fuzzy PID control steam pressure with PLC programming language, and changes the steam pressure by controlling the control output of the electric proportional valve to meet the control requirements. On the basis of analyzing the structure and molding process of the foam molding machine, the physical modeling and mathematical modeling of the control object are carried out, and the rationality of the fuzzy PID control is verified theoretically through simulink simulation; then from the hardware and software The control system was designed, and the fuzzy PID control and the optimization and improvement of the man-machine interface were realized by using PLC in the software. Finally, it was verified by field experiments, and the effect of the pressure control curve and the quality of the produced products were compared before and after the technical improvement. Experimental results show that the control accuracy and stability of the improved control system are better
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