Region tracking control for autonomous underwater vehicle with control input saturation

This paper addresses the region tracking control problem for an autonomous underwater vehicle (AUV) in presence of control input saturation. An adaptive region tracking control scheme is proposed based on nonlinear error transformation and prescribed performance control. In order to achieve region tracking and avoid the tracking error to converge to zero, the error transformation is designed by introducing a time-varying multiple factor and a time-varying additive factor. The new variable after error transformation is treated as virtual error to derive the control law based on the idea of prescribed performance control. It is proved that under the control scheme, the system is semi-global practical finite-time stable, and the range of the real tracking error is given. Finally, the developed control scheme is applied on an AUV, and the simulation results verify the effectiveness of the developed control scheme.