Adaptive nonlinear H<inf>∞</inf> controllers applied to a free-floating space manipulator

Abstract

This paper deals with the problem of tracking control with a guaranteed H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> performance for free-floating manipulator systems with plant uncertainties and external disturbances. Adaptive nonlinear H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> control techniques based on linear parametrization and neural network are applied to this kind of robot. The Dynamically Equivalent Manipulator approach is used in order to obtain experimental results in a planar fixed base manipulator. The main contribution of this paper is that the neural network is used as a complement to the nonlinear H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> control based on nominal model, it is used to compensate only the uncertainties of the free-floating manipulator