MPC-based Docking Control between UUV and Mobile Mothership

With the rapid development of autonomous recycling of unmanned underwater vehicle (UUV), developing new underwater docking solutions to achieve autonomous recycling of parent-child UUV systems has become a hot topic in scientific research. This paper investigates the dynamic docking problem of the parent-child UUV systems. More specifically, a novel dual closed-loop control framework based on model predictive control (MPC) is designed to achieve autonomous docking of UUV. The initial UUV docking control problem is transformed into the design problems of an outer-loop position controller and an inner-loop velocity controller. The design of the inner-loop controller combines the advantages of robust control and backstepping control, and the designed backstepping control law is embedded in the inner-loop controller to address the problems of UUV model parameter uncertainties and external disturbances. Finally, simulation tests verify the effectiveness of the proposed scheme.