Implementation of a High Precision Tension Control Design for a Roll-to-Roll System

Jaeyoung Kim, Korea Institute of Machinery and Materials (KIMM)

In this research, the control design of a high precision web handling in the longitudinal axis for the roll-to-roll (R2R) system is presented. To minimize the tension variation during the web transportation, the decentralized control is utilized in the two winders-based R2R system; the web speed is controlled in the rewinder module and the tension is controlled in the unwinder module, respectively. For the tension control loop, a cascade control strategy is utilized; the velocity control loop (PI control) is located in the inner loop and the tension control loop (PID control) is located in the outer loop, respectively. To reduce the rotational disturbance from the unwinder module in the tension control, adaptive feedforward control is utilized to reduce the undesired disturbance at a specific frequency. Having the experimental scenarios, the tension control performances with the tension feedback only are validated within ±0.79, ±1.32, and ±1.58 percent tension tracking error and 1.6, 1.53, and 1.33 percent web speed error at the speed of 0.1 m/s, 0.2 m/s, and 0.3 m/s, respectively. Compared to the conventional feedback control strategies for regulating the tension, tension control performance combined with the feedback control and adaptive feedforward control can achieve within ±0.53 percent tension tracking error and disturbance signal at specific frequency can be reduced at the speed of 0.1 m/s.