5. Conclusion

The H _∞ synthesis is a method of calculating a corrector based on the manipulation of frequency concepts. It combines the performance tuning of a servo system, characterized by the frequency response of different transfers, with the consideration of robustness objectives such as stability margins or robustness to poorly understood high-frequency dynamics.

We applied this approach to the control of a magnetic bearing. For this application, Automatic Control was not to provide "a corrector", but a methodology, i.e. a systematic means of approaching and solving the problem posed, obtaining results as good as those obtained by an experienced designer using the classical approach. The expected benefits of this methodology are a decisive advantage, even in cases where synthesis using a conventional method is possible:...