Stability evaluation of subassembly considering with gravitational and frictional action

Koshi Makihara, Yasumichi Aiyama

Abstract: We propose an evaluation index of a subassem-bly's stability to search for an assembly posture in the case of assembly for more than three objects. Subassembly is consisted of more than two parts may be broken by some pertubation and gravity while executing trajectory planning by robots. We evaluate the stability using contact state transitions representation when gravity or external force is applied. The stability is evaluated by calculating the work for opposing for gravity and any other pertubation in the state transition. Some numerical results were analyzed in the case of only translational motion for some size of rectangular objects. The results show that the highest evaluation score is determined considering the amount of both gravitational potential energy and friction energy.