Application Of Predictive PID Control In Loosening And Conditioning Process Of Tobacco Industry

In order to cope with the increasingly stringent quality control requirements of the tobacco industry,improve the competitiveness of cigarette,and make the industrial production process closer to the style of product design,the control methods of each key process in the tobacco industry production line have been further studied.Loosening and conditioning process is a key processes of tobacco industry.Its control precision has an important influence on the quality of cigarette products.In order to improve the control accuracy of Loosening and conditioning process and improve the characteristics and quality of tobacco,the equipment manufacturers and cigarette enterprises focus on optimizing PID control parameters,but the control stability is still possible to be improved.Firstly,this paper analyzes the mechanism,structure and work flow of the Hauni company loosening and conditioning machine,combining with the domestic and foreign literature and the specific situation of the loose moisture regain process in tobacco industry;according to the existing loose moisture regain water control mode in a cigarette factory,the predictive control,internal model algorithm and Predictive PID algorithm are studied,and the structures of two predictive PID controllers are deduced.Then,the system platform is built on MATLAB platform with Simulink module,and the applicability and effectiveness of the control mode are verified.The simulation results indicate that: by adjusting the delay time,time constant and other parameters of the controlled system,the output value of the water at the outlet of the loose moisture return process can quickly track the preset value,and the water at the outlet can be stable in the range of 17.4% ~ 17.9%;compared with the traditional PID,the predictive PID can achieve faster response and better stability.Finally,the communication between MATLAB and PLC is realized by OPC protocol,and the real-time control of the loose moisture return machine is realized by using the predictive PID control algorithm.The experimental results show that the control value of the moisture at the outlet of the loose moisture return machine is highly consistent with the theoretical data,which proves that the predictive PID algorithm can be used for the moisture control of the loose moisture return process,and can effectively improve the control accuracy and stability,and guarantee the product quality.