Design considerations of new six degrees-of-freedom parallel robots

This paper describes the structure of three types of parallel robots and compares their performances in the sense of size and static forces. The motivation for this investigation is to construct a robot that best fits a given medical application. The requirements are to cover a given work volume with a given orientation and to maintain the robot within the smallest cube possible. Among the structures examined, three are presented since two are modifications of known structures and the third is a new one