抄録
In order to synthesize a parallel mechanism which satisfies conditions on output velocity characteristics and motion transmissibility given as design specifications, this paper focused on instantaneous center/screw axis. Output velocity characteristics, such as isotropy and translational/rotational velocities ratio, of planar mechanism with three degrees of freedom were generally investigated using three instantaneous centers of the output link. Input-output velocity relationship and transmission index of planar 3-RPR parallel mechanism were formulated using three centers. A kinematic synthesis method of this mechanism and a synthesis example were presented.