Research And Design On Multivariable Temperature Intelligent Control System Of The Eccentric Rotor Extrusion Process

Polymer products can be seen everywhere in daily life and the main component of the traditional polymer-molding equipment is the screw.The polymer molding process in the traditional equipment is dominated by the shear flow,with the disadvantages of high energy consumption and long thermo-mechanical history.The eccentric rotor extrusion equipment is a new type of polymer-molding equipment and the main components of it are the stator and the rotor,instead of the screw.The extrusion process of the eccentric rotor extruder mainly depends on the elongation flow,which can effectively overcome the shortcomings of the traditional screw equipment.Because the mechanical structure and the molding principle of the eccentric rotor extruder are quite different from the conventional screw equipment,the eccentric rotor extruder has a higherrequirementfor barrel temperature control.The temperature should be able toavoid coupling effect as well as keep accurate steady state control.In addition,temperature is also an extremely important factor in the polymer molding process,affecting the quality of polymer products in terms of fluidity,tensile properties,and bending properties.Therefore,the development of intelligent temperature control system with high control accuracy and selftuning function is of great significance for the improvement and promotion of eccentric rotor extruder.Based on the eccentric rotor extruder,this paper studies and designs the temperature control system.The PLC is used as the master controller of the control system.The thermocouples are connectedto the input module of the PLC,in order to feedback the temperature signal.The output module of the PLC outputs the PWM signal to the solid-state relay,and then the heaters,which are installed on the stator of the extruder,are controlled by the solid-state relay.The PLC uses idustrial Ethernet to exchange information with the host computer.The host computer is developed based on the LabVIEW softwore,which is convenient for humancomputer interaction.The host computer can realize functions such as switch control,alarm status reminder,and temperature curve display.The temperature signal collected by the thermocouples is tried to filter by different filtering algorithms.Compared with the effect of different algorithms,it is found that the filtering effect of the Kalman filter algorithm is the best among the algorithms used.After filtering the temperature signal,the system identification tool of MATLAB software is used to identify the model characteristics of the system.Focus on the temperature control system,the Neuron-PID self-tuning controller is designed,and the control effect under different parameters of the Neuron-PID controller is discussed in the SIMULINK simulation platform to verify the reliability and stability of the controller.Furthermore,the particle swarm optimization algorithm is used to adjust the initial value of the Neuron-PID algorithm,in order to reduce the steady-state error and improve the control effect,and the feasibility of the algorithm is tested by simulation.Finally,the PSO-Neuron-PID controller is applied to the eccentric rotor extruder.Through the steady-state response experiment,the resulut shows thatthe PSO-Neuron-PID controllerdidbetterthan the tradtional controller,each temperature zone is kept within the accurate control precision.Different disturbance experiments are also designed to verify the feasibility and the robustness of the controller.The controller not only overcomes the influence of multi-temperature variable coupling in the eccentric rotor extrusion process,but also achieves the aim of steady-state control.The controller also compensates for the lack of research on temperature control of eccentric rotor extrusion process.