CONTROLLER DEVELOPMENT FOR A PROTOTYPE HIGH-SPEED LOW-TENSION TAPE TRANSPORT

This paper describes the entire process of 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, This multiinput /multioutput (MIMO) system has interesting dynamics that make controll er design a difficult, iterative process, The tape speed and tension a re regulated by controlling the torque applied to the supply and the t ake-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 r eel packs, but more challenging are dynamics associated with low-tensi on operation, The spooler operates near a hard nonlinearity, because t he tape only supports positive tension, At low tension, air entrainmen t in between layers of tape in the take-up reel causes the effective s pring constant of the tape to rapidly decrease during start-up. This p aper begins with physical modeling of the transport and proceeds throu gh iterative MIMO system identification and controller optimization. A daptive tension ripple cancellation and fault detection and fault comp ensation are demonstrated. Experimental data are presented which demon strate tape transport at 5 m/s with 0.28 N (1 oz.) tension and a start -up time of less than 150 ms.