Enlightened by the loop shaping theory

a new control algorithm based on closed loop gain shaping is presented through survey of the singular value curve of H ∞ S/T complex sensitivity as well as the correlativity of S and T .The algorithm shapes the closed loop gain without selecting weighting functions.Its core is to determine the final shape of T that is the transfer function of the closed loop system

and the robust controller is directly constructed using parameters having engineering sense.The algorithm guarantees fundamentally that the designed controller has fine control performance and robustness.Based on this algorithm a kind of new robust control algorithm for ships is given.The new algorithm has the advantages of simple design procedure and obvious physical sense.