Type Synthesis of Overconstrained Morphing Mechanisms Based on Waterbomb Origami

Abstract Morphing mechanisms need to alter stable structures to perform different tasks. Origami provides innovative methods for solving multidimensional deformation problems. However, origami structures struggle with poor load-bearing capacity due to the thinness of the panels and their complex deformation makes them difficult to drive effectively. This article transforms origami into a mechanism and proposes a series of two-degree-of-freedom overconstrained units from waterbomb. First, an origami-equivalent mechanism is proposed and transformed into a generalized mechanism capable of forming truss structures. Second, the kinematic pairs are reassigned to reduce the complexity of multi-degree-of-freedom execution. The kinematic pair configurations of the units under overconstraint are established. According to the general process of type synthesis, the case examples are analyzed in detail. The synthesis results are applied to the morphing wing skeleton mechanism. The kinematics of both the unit and the mechanism are derived using the D–H method. Finally, prototype experiments were conducted to evaluate the motion accuracy and stability of the mechanism.