Dynamic Analysis and Active Damping Control for Underwater Vehicle-Manipulator Systems

Underwater vehicle-manipulator (UVM) systems have been suggested for inspection, maintenance, repair and construction of underwater structures. The addition of manipulators to the vehicle makes control of the system more difficult due to the interaction forces between vehicle and manipulator. So, the efficient compensation of those interactions should be considered for accurate control of both subsystems. For precision control of the end-effectors, at the first step, it is essential to analyze the kinematics and dynamics of the whole UVM systems. And then, the robust controller has to be introduced over the interaction disturbances. In this paper, firstly, the kinematic and dynamic analysis about the whole UVM system is executed. The whole dynamics is divided by meaningful terms. And, a robust coordinated motion control algorithm for autonomous UVM systems is considered. For the manipulation, the vehicle movement may be not desirable, because the small movement of vehicle affect significant changes of the end-effectors. And, a vehicle is relatively smaller bandwidth system than manipulators. For this reason, in this paper, active damping control with two-time scale approach for the manipulator is used with passive vehicle. Using this algorithm, the manipulator controller can deal with the vehicle state additionally.