A predictive algorithm for rate control of mechanisms nearsingularities

摘要

A new kinematic algorithm for the control of mechanisms isdescribed, which produces smoother and more accurate control nearkinematic singularities than the usual damped least-squares method. Thenew method predicts the occurrence of singularities, evaluates thesingular terms of the inverse kinematic function using a nonsingularexpression, and smoothly interpolates between the singular andnonsingular forms. The desingularized expression makes use of the ratesof change of the singular vectors and values of the Jacobian matrix;formulas for these derivatives are presented. Simulations of the controlof two and six joint serial manipulators moving through and nearsingular configurations are given to illustrate the method