Control Strategy Research And System Development For A Salt Integrated Case Packer

The development and application of new technology impels the innovation ofindustrial control, and it is also true in the salt packaging industry. In order to improve thedegree of automation and control precision of the salt packaging progress, the research wasbased on PLC and servo system, and high-precision control algorithm was applied to thesystem, not only guaranteeing the high-speed automatic running smoothly of the saltpacking process and also realizing the accurate positioning in control process. The radiofrequency identification (RFID) technology was applied to the system, which mainly aimsat the strong demand of food safety for the present society. The RFID tags were used forinformation tracking, and combined with the warehouse, transportation, sales and otherdownstream links which can form salt traceability tracking system and provide a powerfulguarantee for the safety of salt.The paper firstly studied precise positioning control strategy and realization of controlsystem of salt packaging machine. The paper introduced the current condition of saltpackaging market, analyzed the present condition of the application of various techniques inthe system. Based on the process analysis and control function analysis, we provide theoverall scheme of the control system using modular design. According to the overall controlscheme, each functional module of the software and hardware control was designed andrealized. S7-200Smart was chosen as controller of the system functional requirements forthose function modules, such as box supply, packing, box convey and labeling. The I/Odistribution of the system was completed based on the analysis of the control process,according to its control flow graph, sequential control method to complete the design ofcontrol program was used.A double closed-loop servo control algorithm was put forward, which mainly aimed atthe problem of the cumulative error produced by a long time running of the system. Thealgorithm introduced the fuzzy control for external loop, combined with the innerclosed-loop of servo system, an external closed-loop was built to realize the position information by connecting photoelectric sensor directly to the servo motor and PLC, andthen satisfied the requirement of position automatic on-line correction and accuratepositioning.In the end of this paper, we designed a set of radio frequency identification andlogistics management system, then food traceability tracking system was researched, theinformation of the product as well as the subsequent warehousing, logistics, sales and otherlinks can be written and read. And then the recognition of electronic tags and responseprocess was researched, the construction of the RFID system and the control of electronictag information read and write were completed. Finally process monitoring and datamanagement system was realized.The experiment researches were done for a salt integrated case packer combined withthe hardware devices, such as PLC, Panasonic servo system and Invengo RFID. It achievesthe expected control effect by analyzing the control process and results of the experiments.Finally, the insufficient and prospect was put forward for the control system of theintegrated case packer.