Worst-Case Scheduled Controller Design for Nonlinear Systems

A new procedure of robust control design for nonlinear systems with parametric uncertainty and disturbance is presented. This optimization based approach can design a robust scheduled controller of arbitrary complexity. By taking the worst-case control approach, a minimax optimization problem is formulated. Efficient solution of minimax problems needs the tools of nonsmooth analysis and optimization. A special nonsmooth programming algorithm is implemented. This algorithm is used to solve control design problem for a strongly nonlinear pH process. A wide variety of controllers is designed and their performance results are provided.