Consensus control problem of nonlinear sampled-data fullyactuated ships

Sampled-data consensus control for nonlinear fully-actuated ships is considered. Using a change of state variables of ships and an input transformation, the continuous-time double-integrator dynamics for ships are derived and then applying the continuous-time consensus control theory, continuous-time consensus control laws are designed. Then applying the nonlinear sampled-data control theory, it is shown that emulation (or digital implementation) of the designed continuous-time consensus control laws achieve sampled-data consensus for nonlinear fully-actuated ships in the continuous-time semi-global practical asymptotical (SPA) sense if a sampling period is sufficiently small. A numerical example is given to illustrate the proposed design method.