Cable-truss hybrid double-layer deployable mechanical network constructed of Bennett linkages and planar symmetric four-bar linkages

Abstract

This research proposes a single degree of freedom (DOF) cable-truss hybrid double-layer deployable mechanical network (DLDMN) consisting of equilateral Bennett linkages and planar symmetric four-bar linkages. The kinematics of the equilateral Bennett linkage is investigated. Then a single-loop four-bar hybrid linkage is constructed using the equilateral Bennett linkage and planar symmetric four-bar linkage. The original form of the Bennett linkage in the hybrid linkage is replaced by its alternative form and a synchronous mechanism is introduced to obtain a hybrid linkage interlayer vertical pillar with an adjustable height. The interlayer vertical pillar is employed to a single-layer mechanical network consisting of Bennett linkages. Connecting these pillars with cables, a cable-truss hybrid DLDMN that could fit various surfaces is assembled. An offset paraboloid antenna is set up using the DLDMN. A prototype is manufactured to verify the feasibility of the design. The proposed single DOF DLDMN has the advantages of high deployment ratio of spatial single-loop linkages and normative motion of planar linkages. The proposed network can be used to construct a large-scale spaceborne deployable antenna with high stiffness.