Raptor: Fast bipedal running and active tail stabilization

In this work, we introduce a novel design of bipedal robot inspired by ancient dinosaurs, velociraptor to achieve stabilized high speed running. The skeletomuscular system of a velociraptor is analyzed and applied to determine leg structure and linkage parameters. Foot blades of the robot are made of carbon/epoxy composite structure to absorb shock energy and reduce leg mass for low rotational inertia. Achilles tendons work as a spring-damper system, absorbing and restoring energy with every step for high efficiency running. Raptor's tail take the form of spinning rod to stabilize body posture against disturbances by applying counter torque. The effectiveness of the proposed mechanism is verified through experiments. The Raptor robot runs at a speed of 46 km/h on a treadmill with off-board power. Tail-assisted pitch control provides dynamic stability over 10 cm (21% of the leg length) obstacles.