The Perfuming Automata System Of Tobacco Cutter Line Of Cigarette Factory

Based on the project, Studying and Developing on the Perfuming AutomataSystem of Tobacco Cutter Line of Shijiazhuang Cigarette factory, which iscarried out by Handan Automatization Instrument Institute, the control methodsfor liquid flow, the applications of PLC in process control, the realization ofalgorithm in software as well as the applications of field bus are researched fromtwo directions, theoretic and engineering application.According to the study and analysis on existing measurement technology,control methods, characteristics of executive mechanisms and field bustechnology, the whole development process of Perfuming Automata System wasthoroughly discussed. The discussion dealt with the selection of flow measuringmethods for the liquid with different densities, constitution of control strategyfor liquid flow, design of other auxiliary functions, and the realization ofsoftware and hardware corresponding to the control strategy, measuring methodsand auxiliary functions. The system performance was also validated through aseries of experiments. The project was already checked and received by client.First, the tasks, characteristics and significance of perfuming process oftobacco cutter line in cigarette plant were introduced, then the development offlow control in the field of flow measuring devices, controllers and actuatorswas described from history to present situation. Aiming at the disadvantages ofpresent control systems those are used now in perfuming system of tobaccocutter line in domestic cigarette plant, such as instability of control precision,poor adaptability to the process with various kinds of spicery, discommodiousinterface and lower degree of informatization etc., the necessity to develop a setof perfuming control system which is adaptable to modern management, highlyautomated, simple for operation and friendly in human-computer interface wasindicated. The main study contents of the paper were also clearly listed in thechapter.Every design demands, all control tasks and all auxiliary functions,provided by client were detailedly analyzed one by one in this chapter.Depending on the analysis, the measuring and executive mechanisms, thecontrollers and the interface were designed or selected. The design process wasdone through three steps: in first step the measuring and executive mechanismswere designed and the motivity for liquid flowing in the system was determinedat same time. The key point of this step was to confirm the method formodifying liquid density corresponding designed measuring method. Thus thefull pipeline connection in the system could be worked out. The second step wasto design the functions of controllers. The PID was determined as the controlstrategy for the system; the quantity and tasks of auxiliary functions were alsodetailedly planned in second step. At end of second step the amount of controlpoints was calculated. The third step was to design the functions ofhuman-computer interface. The sorts of the interface were selected and theirfunctions were designed in the step. The development of the system is realization of the general plan. As thesystem was developed for a specifically user, to manufacture it was necessarywork, and the developing process is also the most important content referred bythe paper. The developing process was introduced from 5 parts in the paper. Inpart one the hardware for controllers and electrical system were stationed, thetype selection and specialities of modules in controllers, and the configurationprinciple of electrical system were also described. In part two the type selectionand specialities of measuring and executive components were introduced. In partthree the function realization of communication system was shown throughexplaining communication principle, topology structure, communicationprotocol as well as data exchanging with Upper computer. The development ofhuman-computer interface was described in part four which dealt with thecontents of each screen, the functions of each control elements, and thecharacteristics of selected touch screens. The kernel part of the systemdevelopment was located in part five, programming for PLC, because almost alldesigned functions in general plan would be realized in this part. Therealization of algorithm in main parts of program was illuminated in a way offlow chart. As a whole of system development, the 5 parts progressed not orderlyduring the developing process; repeats and modifying as well as crossover wereoft needed. Just convenient of describing they were divided into 5 parts by logic. Various motions demanded by the system, measuring methods andprecisions, dynamic responsibility and system precision were separatelyvalidated by two static and two dynamic experiments. The recorded experimentdata were firstly transformed into tables or curves, and then were analyzed. Itwas fully testified by the experiment results that adopted control methods wereproper and the general plan was succeed.