Development of Horse-Type Quadruped Robot (Report2, Experiments of Trot Gait by Quadruped Robot PONY)

In this paper, we studied the equine gait, focusing on trotting, to realize a horse-type trot using a quadruped robot. Mammals use energy stored in the tendons during supporting phase. The change of angle in the equine fetlock stretches the tendons, storing energy. Fetlock movement is passively controlled by tendons, not actively controlled by muscles. We developed an equine quadruped robot, which uses actuators consisting of a serially connected motor and spring corresponding to equine muscles and tendons, e.g., the superficial digital flexor muscle. In this paper, we discuss simulation experiments showing the effectiveness of the motor-spring system, then PONY’s horse-like trot.