Exploring Mechanisms Underlying Cheetah-like Rotary Gallop by a Simple Robot

Abstract

Cheetah is the fastest quadruped in the animal kingdom. To understand the mechanisms underlying the high-speed running ability, we focus on the two key characteristics of cheetah running: trunk bending and footfall pattern, known as rotary gallop. While trunk bending contributes to stride extension, the extent to which the footfall pattern contributes to high-speed running remains unclear. To address this issue, we hypothesized that the rotary gallop allows for effective utilization of trunk bending. A previous simulation study suggested that flexible trunk bending in response to the footfall pattern improves running speed. In this paper, we present a simple wheeled robot to verify our hypothesis in the real world.