Variable Structure Controller for Surface Ship Steering

A Lyapunov approach to constructing switching surfaces for variable structure systems is investigated in this paper. The method guarantees sliding mode for any initial condition of the state vector and asymptotic stability is always achieved during sliding motion. An application for the design of a variable structure ship steering controller is carried out and simulation results are presented. The designed controller exhibits robustness as applied to a linear time-invariant ship model and a time varying non-linear ship model operating in an uncertain and time-varying environment