Robust H∞ Output Feedback Control for Nonlinear Systems
The robust output feedback control problem is formulated as a dynamic game problem. The solution to the game is obtained by transforming the problem into an equivalent full state fedback problem where the new state is called the information state. The information state method provides a separted control polcy which involves the solution of a forward and a backward dynamic programming equation. Obtains from the forward equation is the information state, and from the backward equation is the value function of the game and the optimal information state control. The computer implemetation of the information state controller is addressed and several approximations are introduced. The approximations are designed to decrease the online computational complexity of controller.