External force control for underwater vehicle-manipulator systems

The interaction of underwater vehicle-manipulator systems (UVMSs) with the environment is affected by several design constraints such as uncertainty in the model knowledge, presence of hydrodynamic effects, kinematic redundancy of the system, and poor performance of vehicle´s actuating system. The paper presents an external force control scheme for UVMSs that does not require dynamic compensation; however, it can benefit from the knowledge of part of the dynamic model. The possible occurrence of loss of contact due to vehicle movement during the task, is also taken into account. A numerical case study shows the application of the proposed technique in a given task