Global generalised exponential/finite-time control for course-keeping of ships

This paper addresses the global generalised exponential/finite-time control of the nonlinear ship course system with an unknown control coefficient. Different from the well-known Nussbaum-gain adaptive rule, a new Lyapunov-based adaptive logic switching rule is proposed to seek the correct control direction of the ship course system. The main advantage of the proposed controller is that it guarantees the global generalised exponential/finite-time control of closed-loop systems. Theoretical analysis and simulation results show the effectiveness of the developed control method.