On the Terminology for Redundant Parallel Manipulators

Abstract

Different types of redundancy in parallel kinematics machines (PKM) can be used to improve their kinematic and dynamic properties. The meaning of redundancy of PKM is often differently understood in the literature. In this paper a terminology for redundant PKM is proposed. The basis for this classification is a general mathematical model. With the help of this model PKM are regarded as non-linear control systems. The different types of redundancy are clearly distinguished, and their potential applications are discussed. Redundancy is considered from a geometric point of view. Redundancy is a means to deal with singularities of PKM. The different types of singular configurations are considered in the paper, and the potential of redundancy to cope with such situations is discussed. Again singularities are considered from a geometric point of view.