Title :
Active Use of Restoring Moments for Motion Control of an Underwater Vehicle-Manipulator System
Author :
Jonghui Han ; Wan Kyun Chung
Author_Institution :
Nucl. Fuel Cycle Process Dev. Div., Korea Atomic Energy Res. Inst. (KAERI), Daejeon, South Korea
Abstract :
This paper proposes a framework for actively using the restoring moments of an underwater vehicle-manipulator system (UVMS) considering both kinematic and control aspects. The kinematic aspect concerns redundancy resolution of the UVMS where the redundant degrees of freedom are used to selectively optimize the restoring moments. For this, a performance index with variable gradient gain is newly proposed, in which the gain is determined by the result in the comparison of the task direction with the direction of the restoring moments. The control aspect concerns compensation of the restoring forces and moments. In this framework, the control input makes up for the difference between the performances due to the desired dynamics and the restoring moments. This is accomplished by compensation of the restoring forces and moments, which are consistently updated under certain constraints. In addition, the compensation and optimal proportional-integral-derivative (PID) control are merged into a robust adaptive control. The proposed framework requires only masses, buoyant forces, and centers of gravity and buoyancy, not any hydrodynamic parameters. Numerical simulations are presented to demonstrate the performance of the proposed framework, in which a UVMS can perform specific tasks with less control input and achieve smaller tracking errors compared to conventional control systems.
Keywords :
adaptive control; buoyancy; manipulator dynamics; mobile robots; motion control; optimal control; performance index; redundant manipulators; robust control; three-term control; underwater vehicles; PID control; UVMS; buoyancy; buoyant force; center of gravity; compensation; control aspect; kinematic aspect; manipulator dynamics; motion control; numerical simulation; optimal proportional-integral-derivative control; performance index; redundancy resolution; redundant degrees of freedom; restoring forces; robust adaptive control; selective restoring moments optimization; task direction; tracking error; underwater vehicle-manipulator system; variable gradient gain; End effectors; Joints; Performance analysis; Vectors; Vehicle dynamics; Vehicles; Redundancy resolution; robust adaptive control; underwater vehicle-manipulator system (UVMS);
Journal_Title :
Oceanic Engineering, IEEE Journal of
DOI :
10.1109/JOE.2013.2241931