Finite-time control method for distributed formation of ships based on finite-time observer

  Objectives  In order to solve the formation control problem of multiple ships whose velocity measurements cannot be used directly and the environment disturbances are bounded, a finite-time control method for the distributed formation based on finite-time observer (FTO) was proposed.

  Methods  Firstly, a FTO was designed according to the position information of ships to observe the velocity state. Then, under the communication structure where the navigation information was only locally known, the finite-time control law of the distributed formation of multiple ships was designed by using the observation values and homogeneous method, so that multiple ships can track the desired trajectory in a finite time and keep the desired formation at the same time. Finally, according to the homogeneous theory and Lyapunov's stability criterion, it was proved that the error signal of the whole closed-loop system converged in finite time.

  Results  The simulation results show that the proposed finite-time formation control method can provide faster convergence speed, higher control accuracy and better disturbance rejection ability for multiple ships than the asymptotically convergent formation control method.

  Conclusions  The study in this paper can provide reference for the formation control of multiple ships.