Joint dominance coefficients: A sensitivity-based measure for ranking robotic degrees of freedom

Abstract

Many robotics applications require a weighting scheme for individual degrees of freedom in a kinematic linkage. Such schemes are used for example in path and motion planning algorithms to penalize large end-effector movements or scale distance computations for the retrieval of nearest neighbors. Most often, the weights are manually picked and heuristically adjusted for specific linkages. In this paper we propose joint dominance coefficients as a universal tool for estimating the influence of each degree of freedom of a robot on the overall robot displacement. The measure is easy to compute, converges quickly and can be applied to any kind of parameterized kinematic linkage, including tree-structured and closed kinematic chains. A mathematical derivation is provided along with application examples for various robotic linkages. The results show that the method accurately and reliably yields the desired weights. © 2009 Springer-Verlag Berlin Heidelberg.