Robust control of tape transport systems with no tension sensor

Controllers for reel-to-reel web transport systems, such as tape drive systems, often employ costly tension sensors. This paper develops a control scheme that does not require such sensors. It is robust to certain motor parameter uncertainties and to a nonlinear phenomenon called "air entrainment". The observer-based controller uses estimates of the spring and damping parameter trajectories, and performance is guaranteed when the error in these estimates is less than a known bound. The web velocity settling time is guaranteed, and it is ensured that tension remains in a certain range. This performance is proven analytically and demonstrated in simulation.