Geometrical Properties of Modelled Robot Elasticity: Part I — Decomposition

Abstract

Abstract A new geometric decomposition is introduced that diagonalizes the 6 × 6 stiffness and compliance matrices which model robot elasticity. Using screw theory, a congruence transformation is developed from the three orthogonal wrench-compliant axes and the three orthogonal twist-compliant axes. The diagonal elements are the stationary values of linear and rotational compliance and stiffness. This generalizes and is analogous to principal axes and principal values for stress, strain, and rotational inertia. It is proved that the decomposition always exists for both the nonsingular and singular cases.