Robust control system analysis and synthesis

This paper considers two topics in the area of robust control system analysis and synthesis. The first topic is concerned with the testing for zero inclusion of 2-D convex polytopes, which is essential in the robustness analysis of linear systems based on generalisations of Kharitonov´s four-polynomial concept. Barmish (1989) has extended the Kharitonov approach to the more general case of polynomials subject to linearly dependent coefficient perturbations and more general zero location regions, but this is accompanied by various computational problems. These are analysed and two new more direct and computationally less intensive approaches, which produce much more accurate results, are presented. The second topic is concerned with a modification to existing dyadic and full-rank pole assignment design methods for MIMO uncertain systems having affine linear perturbation structures, in which a gain factor is introduced in order to ensure robustness stability and performance. An illustrative example is also included.