Motion Analysis of Spatial Deployable Mechanism Driven in Straight Line

Abstract

Combining linear mechanism with origami mechanism, a new type of space developable mechanism is designed and its motion is analyzed. When four edges of kite-shaped cardboard are abstracted as components and vertexes are abstracted as revolute joints by using abstract thinking theory, a two-DOF kite-shaped mechanism with seven bars is proposed. By means of geometric method, the conditions of realizing straight-line motion of the executive component are studied and parallel restriction is introduced to design the single-DOF kite-shaped linear mechanism. Based on the straight-line mechanism, two types of modules named external module and internal module are constructed and modular principle of the kite straight-line deployable mechanism is explained. According to the kinematic geometric characteristics and face symmetry of Miura-origami mechanism, a new driving method of this origami mechanism is proposed by changing the distance between collinear equidistant points on the symmetrical plane which can be realized by the kite-shaped straight-line developable mechanism. Corresponding virtual prototype model of the spatial developable mechanism is established, and the movement interference and its influencing factors are studied. The performance atlas of folding ratio is drawn and it shows that the folding rate of the space expandable mechanism increases with the decrease of the thickness h and increase of the removal length c which can provide reference for structural design and engineering application of the mechanism.