Development of Horse-Type Quadruped Robot. 2nd Report. Experiments of Trot Gait by Quadruped Robot PONY.

Abstract

The mammals use energy which stored in tendons when they swing their limb. In this paper we concentrate on the gait of the horse, especially a trot. The purpose of this study is to realize horse-like trot srait by a quadruped walking robot. The change of angle of equine fetlock joint makes the tendons stretch. When the tendons stretched, they store up energy. Motion of fetlock joint is not controlled actively by muscles but controlled passively by tendons. Authors have made a horse-type quadruped walking robot PONY. The PONY has actuator systems for fetlock joints which a motor and a spring connected in series. This system corresponds to equine muscles and tendons for example a superficial digital flexor muscle. ln this paper, first, simulation experiments showed that effect of the motor-spring system. Next, the PONY realized horse-like trot gait.