Deployable polyhedron mechanisms constructed by connecting spatial single-loop linkages of different types and/or in different sizes using S joints

This paper deals with the construction of deployable polyhedron mechanisms (DPMs) by connecting spatial single-loop linkages of different types and/or in different sizes. Linkages consisted of symmetric spatial triad units, including Bricard linkages, 8R (revolute joint) linkages and 10R linkages, are adopted as faces to form polyhedrons. These mechanisms exhibit single-DOF deployable motion and can be deployed through two ways. Several mechanisms based on 8R/10R linkages have multiple modes and can switch modes through transition configurations. Three types of DPMs are addressed: the first type is assembled using distinct types of linkages; the second type is constructed by connecting the same type of linkages in different sizes; and the third type has multiple layers composed of the first two types.