Global Solution to an H-infinity Control Problem with Input Nonlinearity

This paper gives a global solution to an H-infinity control problem for systems with symmetric state matrix and state-dependent input matrix. A simple, closed-form expression for the minimizing controller is obtained. This is in contrast to already established theory in which nonlinear H-infinity problems are solved locally. The result is then illustrated through an example, and the potential for controller sparsity is highlighted. Applications to large-scale systems are discussed.