Analysis of wheeled mobile flexible manipulator dynamic motions with maximum load carrying capacities

A computational technique is developed for obtaining optimal trajectory of mobile manipulators with flexible links and joints to maximize their load carrying capacity for a given point-to-point task. In classical robotic manipulators, load carrying capacity mainly is limited by their actuators' capacity constraints. But, this problem in flexible mobile manipulators is more complicated. This is due to extra degrees of freedom, which arises from combined motion of the base and manipulator, and limited motion accuracy as a result of link and joint flexibilities. The final dynamic equations are organized in a closed form similar to classical rigid manipulator equations. Then, the problem of dynamic load carrying capacity on flexible mobile manipulators is converted into a trajectory optimization problem, which fundamentally is a constrained nonlinear optimization problem. Dynamic equations are formulated in the state space form and linearized. Then, Iterative Linear Programming (ILP) method is developed to determine dynamic load carrying capacity of mobile manipulators. Finally, by two numerical examples involving a PUMA robot mounted on a linear tracked base and a wheeled mobile manipulator using the method is presented and the results are discussed. (C) 2004 Elsevier B.V. All rights reserved.