Robust feed-forward/feedback design for tape transport

The purview of this paper is the design of controller which include knowledge of parametric uncertainties and their distributions. The parameter distributions are approximated by a finite set of points which are calculated by the unscented transformation. This set of points is used to design robust controllers which minimize the worst performance of the plant over the domain of uncertainty. The proposed technique is illustrated on a tape transport system. Two approaches to arrive at robust prefilters and feedback controllers are proposed. The first, which involves sequential design of the feedback and prefilter and the second, which simultaneously arrives at optimal parameters of the feedback gain matrix and the time-delay prefilter. Numerical results illustrate desirable response over the operating region of the system.