Development Of Electrical Control System Of Heavy Film Bag Forming Machine

With the rapid development of economy in our country, the demand for heavyfilm packaging products will continue to increase. At present, there is a huge lackof bag forming machine products which can process heavy film. To meet the marketdemand, our company intends to develop a new heavy film bag forming machinethrough understanding, digesting and absorbing the similar domestic andinternational equipments. This thesis aims at designing and implementing itselectrical control system and control algorithm of critical control unit.Firstly, this thesis starts with the production crafts and technical requirementsof heavy film bag making machine, designs its total mechanical structure andproduction process, and determines the control requirements of its control system.Based on the analysis of the control process of heavy film bag forming machine,the design and development of its electrical control system is completed, including:main control system of S7-300, servo control unit and temperature control unit.Secondly, in order to improve the control performance, product quality andproduction efficiency of film bag forming machine system, the advanced controlalgorithms are used in two critical control units. For the control of bag length, theservo control unit of bag carrying machine uses iterative learning control algorithm.And sealing temperature is controlled by fuzzy self-adjusting PID control algorithm.This thesis provides the principles of the two algorithms, mathematical modelingand simulation of the system. And through the simulation, related parameters ofthese two control algorithms are confirmed which lays the foundation for therealization of the system algorithm.Finally，whole automatic control system based on S7-300PLC of film bagforming machine is realized by software programming, including the design of themain control system program, communication network, servo control systemprogram, HMI program. Iterative learning control and fuzzy self-adjusting PIDcontrol are both realized in PLC. The experiment and actual operation results showthat using advanced control algorithm can greatly improve the precision andstability of the control system.The film bag forming machine designed in this paper can achieve highautomation level and overall performance. It has been used in the market, andproduces a well economic benefit.