Multivariable application of μ-analysis to servo system design in the consumer electronics industry

The design of high performance servo systems typically used in consumer electronics applications, such as compact disc equipment involves emphasis on robustness, to account for product variations and tolerances. In the last years much research effort has been devoted to the multivariable robustness analysis problem. An important development is based on norm-bounded uncertainty modelling using singular values as indicators. Its major disadvantages is its conservatism, meaning that the uncertainty model set is larger than necessary. For that reason J.C. Doyle (1982) introduced structured singular value analysis. This method has enlarged the nonconservative applicability tremendously. The norm-bounded uncertainty modelling is presented in state space, and the structured singular value method is briefly discussed. The method is applied to an electro-mechanical actuator