Basic interaction operations for an underwater vehicle-manipulator system

In this paper an underwater vehicle-manipulator system is considered in order to accomplish two operations, namely to turn a valve and to push a button. Realistic assumptions, such as imperfect knowledge of the environment, have been considered with the purpose to design the proper interaction control scheme. In addition, due to the poor knowledge of the underwater dynamics, model-based approaches have been avoided. The UVMS is characterized by 13 Degrees-Of-Freedoms (DOFs) and a proper task-priority, inverse kinematics controller has been designed to take into account all the DOFs, however, this paper focuses on the interaction part. The redundancy exploitation is an ongoing activity being the interaction approach fully decoupled, and thus compatible, with the redundancy resolution scheme. The validation has been achieved resorting to a realistic mathematical model, including the main dynamic effects.