Research On The Tension Control For Unwinding/Winding Process Of The Gravure Press Macine

Tension control is a very important part of process control in printing and packing service. Good tension control improves product quality and productivity. Main subject discussed in this dissertation focus on the unwinding or winding tension control for the gravure press machine.A web tension control system features great dynamics change, strong coupling between web velocity and tension, and many sources of disturbance. In this a system, traditional PI control can not satisfy the requirements of control precision and system stability. So we must modify the control strategy to meet the needs. First, integral-separation PID control strategy is used to eliminate the integral accumulation errors that may be introduced by such processes as running or stopping main machine, sudden acceleration or deceleration, etc. Second ,the feedforward control significantly improves disturbance rejection performance and system stability. Third, a new structure of PID control reduces the damping ratio of the control system. Finally, the author deduces a new mathematic model and obtains a different conclusion from other papers.The author has finished the design of a tension controller for the unwinding process of the gravure machine and of a driver for magnetic powder brake. Including: (l)Finishing a tension controller based on a microprocessor; (2)Designing a constant current driver for the magnetic powder brake which has a good response characteristics; (3)Completing the program design which has perfect control function; (4)Designing the operation curves for the practical process, optimizing the tension controller performance.