Abstract
This paper presents the design and evaluation of a discrete time adaptive control scheme for mechanical manipulators. In general, the dynamic models of a mechanical manipulator are described by nonlinear differential equations and many adaptive control schemes based on those models have been proposed. In practical apprications, however, these continuous time control schemes are usually implemented using difference approximation of the differential operations. In this study, a new type of non-linear discrete time model is adopted as the approximate model of the mechanical manipulators. This model is obtained by applying numerical discretization techniques to the minimization problem of the action functional. The validity of the proposed adaptive control scheme is evaluated by the control performance in experiments. Extensive experimental results for a direct driven (DD) robot show the effectiveness of the proposed scheme.
