Abstract
Rapid reacting motions should be needed for robots working in human environments. Preliminary motions are expected to improve speed of such motions. Thus, we investigated preliminary motions in such complex environments. In this investigation, we calculated expected value of minimum time for state transition of a simple robotic arm model. In addition, we compared the value of cyclic motions with stopping as preliminary motions. As a result, we found that stopping states make speed of reacting motions more fast when target states can be predicted enough and cyclic motions may make the speed more fast when it is difficult to predict target states.
