Type synthesis of parallel mechanisms with multiple operation modes

There are usually several motion patterns having the same degrees of freedom (DOF). For example, planar motion, spherical motion, and spatial translation are motion patterns with 3 DOE An f-DOF parallel mechanism with multiple operation modes is a parallel mechanism that can generate different motion patterns with f DOE Up to now, no method has been proposed for the type synthesis of parallel mechanisms with multiple operation modes. This paper presents a general method for the type synthesis of parallel mechanisms with multiple operation modes. Using the proposed approach, 3-DOF parallel mechanisms with both spherical and translational modes, i.e., parallel mechanism generating both a spherical motion pattern and a spatial translational motion pattern, are generated systematically. A large number of parallel mechanisms with both spherical and translational modes are obtained.