Mobile assembly of two Bennett linkages and its application to transformation between cuboctahedron and octahedron

摘要

The Bennett linkage has been proposed as a building block of deployable structures as it can generate desirable spatial motions with the least number of links. However, these deployable structures are based on the tiling of Bennett linkages. No spatial assembly of Bennett linkages has been developed to form any transformation between regular and semi-regular polyhedrons. In this paper, we propose a new type of mobile assembly consisting of a pair of Bennett linkages connected by four spherical joints. We show that this particular assembly can be used to construct transformable polyhedrons. Using an alternative form of such assembly, a polyhedral transformation between cuboctahedron and octahedron with one degree of freedom is realised. The axes of the revolute joints within the Bennett linkages are determined by the geometrical relationship between the deployed geometry and the folded one. The transformation between two polyhedral shapes has no bifurcation which is proven through kinematic analysis and demonstrated by a physical model. This transformable polyhedron has great potential for the aerospace applications where transportability and protection of payload are critical design features. (C) 2019 Elsevier Ltd. All rights reserved.