Algorithms for a Versatile Two-Degree-of-Freedom Robot Wrist

Abstract

Two-degree-of-freedom wrists are examined with the objective of formulating designs which will allow three-degree-of-freedom performance by means of repeated use of the two available freedoms. Both axes must either be fixed with respect to the arm or move with the wrist. Friction drive designs are examined. Algorithms are presented for the achievement of the objective. There is a performance penalty involved, which for some manoeuvres is appreciable, but which for others is negligible.