ADAPTIVE TABULAR PULSE-WIDTH CONTROL OF A PRISMATIC ALLY JOINTED MANIPULATOR

摘要

Pulse-width control, when applied to single degree-of-freedom systems, has been shown to be very effective in achieving high-precision positioning in systems subject to the undesirable effects of Coulomb friction and stiction. This paper describes continuing work into the application of pulse-width control to systems with more than one degree of freedom. Specifically, this research focuses on the development and implementation of adaptation schemes for tabular pulse-width control. Results are presented based both on simulations and experiments using a two degree-of-freedom prismatically jointed manipulator developed at Bucknell University. These results show that Normalized Least Mean Square (NLMS) adaptation of tabular pulse-width control consistently achieves positioning accuracies equal to that of the sensing devices employed. Moreover, adaptive tabular pulse-width control is shown to be effective with relatively small tables even with significant parameter variations and problematic system behavior.