Design and analysis of a metamorphic mechanism cell for multistage orderly deployable/retractable mechanism

Normal kinematic joint can be transformed to variable kinematic joint(VKJ), which refers to a kinematic joint that is capable of topological variation in a mechanism, by utilizing effect of friction and self-locking. In this paper a metamorphic mechanism cell which can realize deploying, self-locking, unlocking, retracting and interlocking with other cells, is designed by incorporating VKJs. Self-locking margin is proposed to estimate the self-locking capability. The variable topology configurations of this cell are presented and the mobility of this cell is analyzed. With the new metamorphic cell, a cable-driven telescopic model with 3 tubes is built, and its motion simulations are conducted to verify the design method. The results demonstrate that the impact in transformation is mitigated and multistage orderly deployable/retractable mechanisms can be built by this method.