Controller development for a prototype high-speed low-tension tape transport

This paper describes the entire MIMO process control system design for a prototype tape spooler that is used for conducting research into the dynamics of high-speed and low-tension tape transport. The tape speed and tension are regulated by controlling the torque applied to the supply and the take-up reels. Each reel is directly driven by a motor, and no capstan is used. The system has slowly time-varying dynamics due to changing reel packs, but more challenging are dynamics associated with low-tension operation. The spooler operates near a hard nonlinearity, because the tape only supports positive tension. At low tension, air entrainment in between layers of tape in the take-up reel causes the effective spring constant of the tape to rapidly decrease during start-up. This paper describes: physical modeling of the transport, iterative MIMO system identification and controller optimization. Adaptive tension ripple cancellation and fault detection and compensation are demonstrated.