Research On Co-extrusion Control System For Single-screw Extruder

As primary molding equipment in the production of double-deck cylindrical propellant, the control precision of pressure at the head of Single-screw extruder directly affects product quality. At present, the production lines mainly use artificial methods to control the operation of single-screw extruder,so that,the value of the pressure could be adjusted, but it is susceptible to subjective factors, time-consuming and laborious, and disadvantage in real-time. In addition, because of the properties of flammable, explosive and improperly control, it easily leads to safe accidents. Therefore, improving the control precision of the pressure and keeping its stability, realizing the automation of the production process of propellant is of great significance for getting high product quality and ensuring product safety.From the perspective of the actual needs of production, the co-extrusion process and its key factors is firstly analyzed, according to technical requirements, the blue print of the extrusion control for single-screw extruder is put forward; For co-extrusion process has characteristics of time-delaying, time-varying, non-linear, multivariable, the parameters self-tuning PID control strategy is proposed, the defects in PID parameter tuning for inconveniency in co-extrusion production process and imprecise pressure control accuracy is resolved; For the process control in the production of double-deck cylindrical propellant, a set of the co-extrusion control system for single-screw extrusion as the core of industrial computer is designed; Monitoring software is developed by VC++6.0, achieves centralized control of the co-extrusion process; From the three elements of electromagnetic interference, the effective scheme to anti-interference is proposed by the use of hardware and digital filter synthetically, reliability and stability of control system is improved.By comparison test, the parameter self-tuning fuzzy PID control is better than conventional PID control,it can effectively control pressure precision within the requirements of the target, and has a smaller overshoot, shorter settling time and control more accurate. The control system has been running by debugging, it meets the needs of the business users for simple operating, friendly interface and high stability.