Design and Analysis of a Multisegment Shape Morphing Mechanism

This article presents a novel design of a multisegment shape morphing mechanism that combines a lockable reconfigurable variable geometry truss manipulator (VGTM) with an active parallel compliant mechanism. The structure of the VGTM is in a parallel-serial structure, and its hyper-redundant degree-of-freedom (DOF) can be fully controlled by using two active flexible panels and some lockable joints. This mechanism is suitable for aerospace applications that require light and compact structure with high load-carrying ability as well as achieve multiple DOFs for large-scale shape deformation. To make shape morphing process simple and efficient, the mobility and topological configuration of the mechanism are analyzed first. Then, a control strategy combining the approximate motion mode and the exact motion mode is proposed. The kinematic models for different motion modes are established and solved analytically. It has been found that, under the exact motion mode, two approaches could be realized for the pose control under external loads for each segment. The one with the shorter moving path is selected in this article. Finally, a prototype was constructed to demonstrate the feasibility of this structure and to verify the proposed kinematic model.