ADAPTIVE STABILIZATION OF MOBILE MANIPULATORS

This paper considers the motion control problem for uncertain mobile m anipulator systems comprised of a robotic arm mounted on a wheeled mob ile platform. More specifically, we address the problem of stabilizing mobile manipulators in the presence of uncertainty regarding the syst em dynamic model. It is proposed that a simple and effective solution to this problem can be obtained by combining ideas from homogeneous sy stem theory and adaptive control theory. Thus each of the proposed con trol systems consists of two subsystems: a (homogeneous) kinematic sta bilization strategy, which generates a desired velocity trajectory for the mobile manipulator, and an adaptive control scheme, which ensures that this velocity trajectory is accurately tracked. This approach is shown to provide arbitrarily accurate stabilization to any desired co nfiguration and can be implemented without knowledge of the details of the system dynamic model. Moreover, it is demonstrated that exponenti al rates of convergence can be achieved with this methodology. The eff icacy of the proposed stabilization strategies is illustrated through computer simulations with two mobile manipulators. (C) 1998 John Wiley & Sons, Inc.