Thesis (M.Eng.)--Chulalongkorn University, 2007

The AUN/SEED-Net benchmark problem rendered at the field wise seminar in Bangkok, Thailand in 2006 is a rotary double inverted pendulum (RDIP). The primary objective of this research is to a design robust controller for the RDIP using Linear Matrix Inequalities (LMIs). The system is required to be stable at the upright unstable position regardless of some parametric uncertainties and disturbances. In addition, the minimization of a given criterion function must be considered. The effect of the disturbances on the system needs to be attenuated. The LMIs tool is a very powerful one in the study of design controllers. Many design problems can be cast as convex problems such as an LMI minimization problem and a robust stability test of closed-loop systems. This thesis is concerned with the design of a robust H[infinity] state feedback controller and a robust H[infinity] output feedback controller.