Robust regulation and tracking system design for multivariable control of the tape transport mechanism

Abstract

Tape mechanisms must be able to transport the tape with a constant velocity for achieving high rate of data transfer. In this paper, a multivariable model of tape transport mechanism including the take-up and supply reel servos for tape tension control and capstan servo for speed control is considered. To achieve desired performance, pole-placement approach based on general canonical control form (GCCF) is used. Instead of using expensive tension sensors, an observer is designed. A regulator system is developed for disturbance rejection; and a modified integral control is designed for perfect tracking of desired set-points in tape speed and tensions. Since the real dynamic model associates with parametric uncertainties, an algorithm is developed for robust pole-placement. Eigenvalues of the uncertain control system are chosen such that appropriate responses are achieved while control efforts remain small bounded. Results show that robust performance is obtained for uncertain models with various parametric uncertainties.