BigDog Quadraped Robot

From Boston Dynamics () comes this odd-looking, gasoline-powered robot that looks like two guys carrying a couch, but acts almost alive. “BigDog is powered by a gasoline engine that drives a hydraulic actuation system. BigDog’s legs are articulated like an animal’s, and have compliant elements that absorb shock and recycle energy from one step to the next. BigDog is the size of a large dog or small mule, measuring 1 meter long, 0.7 meters tall and 75 kg weight. BigDog has an on-board computer that controls locomotion, servos the legs and handles a wide variety of sensors. BigDog’s control system manages the dynamics of its behavior to keep it balanced, steer, navigate, and regulate energetics as conditions vary. Sensors for locomotion include joint position, joint force, ground contact, ground load, a laser gyroscope, and a stereo vision system. Other sensors focus on the internal state of BigDog, monitoring the hydraulic pressure, oil temperature, engine temperature, rpm, battery charge and others. So far, BigDog has trotted at 3.3 mph, climbed a 35 degree slope and carried a 120 lb load.“