Analysis of biped running with rotational inerter

To realize energy efficient and high speed biped locomotion, many control method and optimal configuration were proposed. In the research field of passive dynamic walking, some researchers focused on the mechanism and confirmed that robots applied with mechanical impedances like spring have good performance of locomotion. The rotational inerter was also proposed as one of the mechanisms to increase robot's mechanical impedances, and it was showed that the rotational inerter also has the effect to improve performance of locomotion. However, the details why the rotational inerter improves the performance of locomotion has not been clear, hence the optimal way to apply the rotational inerter has not been clear too. In this paper, we thus investigate biped running of humanoid robot with applying the rotational inerter with different ways. From the result, we give a guide to apply the rotational inerter to improve running performance.