New measure for ‘Closeness’ to singularities of parallel robots

Since a parallel robot is always out of control at a singularity and its neighborhood, it should work far away from singular configurations. However, how to measure the closeness between a pose and a singular configuration is still a challenging problem. This paper presents a new measure for closeness to singularities of parallel robots. Several performance indices are introduced by taking into account motion/force transmissibility. By using these indices, a uniform metric can be founded to represent the closeness to singularities for all types of parallel robots.