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Indexed by:Journal Papers

Date of Publication:2020-01-01

Journal:JOURNAL OF MECHANICAL DESIGN

Included Journals:SCIE

Volume:142

Issue:1

ISSN No.:1050-0472

Abstract:An open path synthesis method for a spatial revolute-revolute-spherical-spherical (RRSS) mechanism is presented in this paper. The mathematical model for the trajectory curve is established. The characteristics of an RRSS mechanism in a standard installation position are revealed.' the projection points of the coupler curve on the Oxy plane rotate by the corresponding input angles around the z-axis, and the generated points lie on an ellipse. Based on this finding, a 17-dimensional path generation problem can be translated into two lowerdimensional matching recognition problems and one actual size and installation position calculation problem. The path generation can be achieved by three steps. First, a database offour dimensional rotation angle parameters is established. By comparing the similarities between the mechanism feature curve of the prescribed open curve and its corresponding mechanism feature ellipse (MFE), the angles of installation, the initial angle of the input link, and the elliptic feature parameters of the desired RRSS mechanism can be approximately determined. Then, a 13 -dimensional dynamic self-adapting numerical atlas database is established, which contains six basic dimensional types (BDTs) and seven waveletfeature parameters, and the BDTs of the desired RRSS mechanism are obtained. Finally, based on the relationship between the MFE of the prescribed curve and the BDTs of the desired RRSS mechanism, the calculation models for the actual link lengths and installation positions of the desired RRSS mechanism were established. Three examples are presented in this paper.