Getting up Motion Planning using Mahalanobis Distance

This paper presents a motion planner of getting up motion using Mahalanobis distance. It is an indispensable function for humanoid robots to get up by itself and some humanoid robots are able to get up by themselves, but the motion can start only from the states specified a prior. The robots have to get up from an arbitrary lying state which may result after an unexpected falling. The proposed method (l) determines the degree of similarity between the current falling state and predefined falling states using Mahalanobis distance, (2) generates a collision-free motion to the most similar state, and (3) plans a sequence of motions using a state transition graph.