External force control for underwater vehicle-manipulator systems

This paper presents an external force control scheme for underwater vehicle-manipulator systems (UVMS). Interaction of an UVMS with the environment is affected by several control 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 proposed control scheme 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. Extensive dynamic simulations prove the effectiveness of the proposed control algorithm.