Research Of Constant-Tension Control In Gravure Press Machine

Tension control is a very important part of process control in chromatic printing and packing service. Good tension control improves product quality and productivity. Main subjects discussed in this dissertation focus on the tension control in unwinding and winding processes for the gravure press machine.A film tension control system features great dynamic change, strong coupling between film velocity and tension, many sources of disturbance in winding and unwinding processes, and also a non- linear system. The tension among machines is coupling too. The tension in any place will lead to tension fluctuation in other places. Tension control becomes more difficult because modern gravure press machine possessing high speed and auto material-exchanging. In this system, traditional PI control can not satisfy the requirements the precision of tension control and the stability of control system. So we must modify the control strategy to meet the needs. First, integral-separation PID and speed-changing integral PID control strategies are used to eliminate the integral accumulation errors that may be introduced by such processes as running or stopping main machine, sudden acceleration or deceleration, auto material-exchanging, etc. Second, a new structure of PID control reduces the damping ratio of the control system. Finally, the author deduces a new mathematic model and establishes the state-space equation.A tension controller has finished for the unwinding process of the gravure printing machine, which main control setup is 80C196KC singlechip and which control elements are magnetic powder brake and magnetic powder clutch. Finally hardware is simply clarified in this dissertation.