Abstract
A motion planner of emergency stop must make an operating humanoid robot to a stationary state from the emergency signal. It plays an important role in prevention of falling over because humanoid robots fall over easily. Immediately after the emergency signal, the emergency stop motion must be generated in real-time. We model a humanoid robot as a simple dynamic system consists of the ZMP (Zero-Moment Point) and the COG (Center of Gravity) as its states. The emergency stop motion is generated by a state feedback. We determine optimal feedback gains in terms of the initial conditions and the pole assignment. The proposed method realizes a reliable emergency stop with low computational cost. Furthermore, it can easily predict the possibility of the successful emergency stop at any time. The validity of the proposed method is confirmed by some experiments using humanoid robot HRP-2.
