GEOMETRIC SYNTHESIS AND ENUMERARTION OF THE FAMILY OF 3-DOF TRANSLATIONAL PARALLEL MANIPULATORS VIA THE SCREW THEORY

摘要

In this paper, a systematic method based on the screw theory is proposed for the geometric synthesis of a family of 3-DoF translational parallel manipulators (TPMs). The theory of screws and reciprocal screws is employed for the analysis of the geometric conditions undergoing the different types of constraints for the TPMs. In terms of these established geometric conditions, limb structures that can be used for constructing TPMs are enumerated, and a number of novel TPMs including both symmetrical structure and asymmetrical structure are synthesized accordingly. On the other hand, some composite kinematic pairs are proposed. The involvement of these composite kinematic pairs into the limbs of a TPM greatly enlarges the family of the TPMs.