Dynamic Modeling, Tension/Position Control Of Discontinuous Flexible Web Transport Systems And The Applications

The discontinuous winding technique of the flexible web is one of the keys in the manufacturing of the flexible electronics, which is important for the effective, low-cost production of the flexible electronics products. The research emphases are the coupling puzzles between tension control and position control in the discontinuous winding jobsites for radio frequency identification (RFID) electronic tags packaging equipments. The tension fluctuation mechanism analysis will be the entrance for the system study. The tension control method and hybrid control method of tension and position for discontinuous web transport systems are proposed based on the system dynamic modeling. Several experiments have been performed, on the platform and the equipment to show the efficiency and feasibility of the control methods. The contributions of the thesis can be summarized as follows.(1) The tension fluctuation mechanism is deeply analyzed for the discontinuous winding systems. The dynamic models are focused on factors, influencing the stability of tensions, such as the time-varying radii of web rolls, the idle rollers and the frictions.(2) It is the basis of the following proposals and actualizations of kinds of control methods to holistically model the discontinuous winding system. A series of dynamical equations of the couple, multiple parameters are developed, by the compositions and characteristics in different sections. The dynamic increment models are established for this multiple input-multiple output discontinuous winding system, and are used to analyze the tensions'alternation with several parameters in different feeding period and zones.(3) Tension control is the principal nodus in discontinuous winding systems, and is one precondition for precise positioning and stable transporting. One decentralized tension control method, including the tension feedback, position feedback, is proposed on the basis of the tension control model. The iterative learning control method is imported into tension control strategy, and proved to be efficient for tension stability control by the simulation.(4) For enhancing the positioning accuracy in the discontinuous winding technologies, a hybrid control method of tension and position is presented, based on the programmable multi-axis controller. The hybrid method is composed by the synchronous position instruction control of 4-axis, the iterative learning control, the decentralized tension control and the adaptive identification of parameters. The hybrid control method ensures both the tension stability and position accuracy in the discontinuous jobsites, and endues the systems with adaptive ability for new kinds of web and environment.Finally, many experiments and analyses are made to testify the proposed results and control methods on the winding experimental platform and the RFID tags packaging equipment. Representative samples of the experimental results show that:1) The number of idle rollers, the time of acceleration and deceleration, and feeding velocity correlate with the fluctuation of tension.2) The position precision is influenced by the velocity, acceleration, and tension stability. Higher accuracy can be obtained in slow feeding rhythm. 3) The control methods are successfully implemented on the packaging product line and show good performance. The application keeps the discontinuous winding system with preferable tension stability and precise positioning.The proposed control methods have been validated in the RFID equipment and achieved good purposes.