Robust control of identified reduced-interval transfer function

We propose and demonstrate the use of a reduced-interval transfer function for robust control design of a system with parametric uncertainty. A singular value decomposition technique is used to model a system with parametric uncertainty via an interval transfer function, where each interval represents one bounded uncertainty parameter. The interval lengths can be used to determine the number of intervals of the reduced-interval transfer function, which is used to form an uncertainty structure for application in robust control such as /spl mu/-synthesis. A major benefit of working with a reduced-interval model is the simplicity and computational efficiency in analyzing and designing the robust controller. Also the order of the designed controller may be significantly reduced by using a reduced-interval model. To verify the system performance of the designed controller based on the reduced-interval model, we present a combined algorithm consisting of a sensitivity analysis and interval polynomial techniques.