Design of a nonlinear H/sub /spl infin// controller applied to a ship control system

A ship course-keeping control system is formulated as a nonlinear H/sub /spl infin// control problem. In order to construct a nonlinear H/sub /spl infin// controller to solve the problem, it is essential to find a solution for the Hamilton-Jacobi equation (HJE). A modified successive algorithm is proposed to obtain an approximate solution of the HJE and then a nonlinear H/sub /spl infin// controller is constructed. Simulations of the closed-loop ship motion responses are provided to illustrate the performance and robustness of the nonlinear H/sub /spl infin// controller.