Design And Research Of The Tension Control System Of Coating Device

Materials, such as paper, textile and thin steel, are unwound from or wound ontothe machine by certain tension control. Therefore, tension control plays a vital role inprocess control of paper making, printing and spinning in industry. Tension control isan important point of coating device control system, whose quality has a great impacton product quality, production cost and production efficiency. Nowadays, with theincreasing quality and quantity demands from customers, tension control containsmuch important practical values. Under this circumstance, the thesis concentrates onthe research of tension control for coating device and building the correspondingcontrol system.The thesis firstly introduces the background and significance of the research, andmake a conclusion for the research status of the relevant technology and developingtendency domestically and overseas. Then analyses the origin of tension, classifiesthe familiar tension control methods and compares the characteristics of each method.Afterwards, the thesis makes a thorough analysis and research on picking the flexiblemembrane-coating device as the study object. Moreover, coating device tensioncontrol system is made up of unwinding, hot-pressing and rewinding, Lastly, themathematical model of the main components is established.The tension control system is a complicated and non-linear system with thecharacteristics, such as multi-inputs and strong coupling. In the respect of controlalgorithm, considering inertia, time-variant parameters of tension control system formembrane coiled material and the effect of tension fluctuation, through principleintroduction of PID control and fuzzy control theory, and discussion on theirlimitations, combining the advantages of them, fuzzy PID control strategy for tensioncontrol system for membrane coiled material was presented. Applying Matlab toestablish a system simulation model and getting the different curves in differentmethods, the simulation analysis of this control algorithm was conducted. By makingthe contrast with the effect the traditional PID controller, it confirms that this fuzzyPID algorithm is suitable in the tension control system.The design of a closed-loop tension control system is dissertated in detail, thesystem is made by the DSP chip as main control unit, the permanent magnet synchronous motor as actuator and the tension sensor for feedback. Comparing thetension force detection signal from the tension sensor with the reference signal, andthen fuzzy PID algorithm used for data processing to adjust the signal of outputcontrol real-timely for the purpose of controlling the membrane tension. The structureof the control system can establish a good foundation for tension control system. Thesystem has decent dynamic performance, steady precision, and is capable of keepingsteady tension in the coating process. The fact validates the feasibility of fuzzy PIDalgorithm, which can achieve satisfying control results.In addition to completing software design of flexible membrane tension controlsystem in detail, including the designs of main program, algorithm programming,data acquisition programming, and communication module programming and so forth.Besides, flowcharts are also made for each module. Finally, the thesis introducessome kinds of effective measures of anti-interference for the system software.