Nonlinear output feedback synchronization control of master-slave vessel with observer backstepping

In this paper, a nonlinear output feedback control law with observer backstepping is designed to control the slave vessels to synchronize with the master vessel, no matter how the master vessel behaves. Firstly, the kinetics and kinematics equations of vessels with three degree of freedom movement are presented. Secondly, a master-slave synchronization control scheme is proposed, which includes an output feedback synchronization controller and a nonlinear observer. The nonlinear observer is used to estimate velocity and accelerate of the slave vessels when only position and yaw angle measurements are obtained. The synchronization position and velocity errors of the master and the slave vessels are quickly converged to zero in application of the derived controller with a nonlinear observer. At the same time, a damping item is introduced in the control process to assure globally exponentially stabile (GES) of the whole system. Then, the designed control law is proved to be GES by the Lyapunov stability theory. At last, simulation results and conclusions are obtained by means of simulating the master vessel tracking a circle trajectory, which indicates that the nonlinear output feedback synchronization control of master-slave with observer backstepping can resolve the synchronization movement problem.