Tuning for robustness and performance using iterative feedback tuning

Iterative feedback tuning (IFT) is a direct tuning method using closed loop experimental data. The method is based on numerical optimization. In each iteration of the optimisation an unbiased gradient estimate is used. In this contribution the results of are refined and developed further. Improvements are introduced on the optimization procedures of the IFT scheme to allow for joint optimization of non-conflicting criteria of stability robustness and performance. Also the case of weighted additive uncertainty is considered as an alternative to the co-prime factor perturbations as used by Glover and McFarlane (1989). Optimization of the estimate of the H/sub /spl infin// robustness criterion is now based on global optimization to increase reliability