Research On The Control Method Of Cable Extrusion Process

As an important basic supporting industry,cable is used in all fields of national economy.With the further development of China's economy and society to the direction of safety and environmental protection,low-carbon energy saving,informatization and intelligence,higher requirements are put forward for the accuracy of cables in various fields.However,there are some problems in the extrusion process,such as low precision,strong coupling and poor stability.In view of the above problems,this study studies the control method of the cable extrusion system.Through a large number of previous experiments,it is found that the ultimate goal of the control of the cable extrusion system is to achieve the accurate control of the cable diameter.In order to realize the real-time monitoring of wire diameter in the production process,the prediction model of wire diameter is established,and the parameters are adjusted in real time according to the prediction results to ensure the accuracy of wire diameter.In the process of parameter adjustment,it is obvious that temperature and pressure have the greatest influence on the system among many process parameters,and they interact with each other and have a strong coupling relationship.Therefore,in order to realize the precise control of a single variable,it is necessary to decouple the temperature and pressure control subsystem of the cable extrusion system.The specific research contents are summarized as follows:(1)The prediction model of wire diameter based on regular extreme learning machine is established.Through the brief analysis of the structure principle and process parameters of the extrusion system,the selection of auxiliary variables and the preprocessing of historical experimental data are realized,and the line diameter prediction model based on regular extreme learning machine is established and simulated.Compared with the simulation results of BPNN prediction algorithm,it can be concluded that the prediction method of regular extreme learning machine is better than BPNN prediction in both fitting degree and error,and it can more accurately predict the cable diameter in the production process.(2)The coupling relationship model of temperature and pressure control system is established,and its coupling and decoupling control mode are analyzed.Through the comparative analysis of decoupling control methods,the inverse decoupling controller is selected to decouple the temperature and pressure system,and compared with the traditional PID.Through the comparative analysis of the simulation curves,it is concluded that the temperature and pressure system under inverse decoupling has faster response time,smaller overshoot and stronger robustness compared with the traditional PID.(3)According to the inverse decoupling model of the temperature and pressure control system,the Tornambe inverse decoupling controller is designed by using the expected dynamic method to decouple the temperature and pressure control system,and compared with the traditional PID controller.Through the analysis of the simulation curve,it is concluded that the Tornambe controller designed by the expected dynamic method not only effectively solves the coupling relationship in the coupling loop,but also reduces the system response time,reduces the system overshoot,effectively suppresses the system disturbance,and has strong robustness.