With its sights on robotic pack mules to help warfighter in operations, DARPA initiated a program that yielded BigDog. The robot’s on-board computer controls locomotion, processes sensors, and handles communications with the user. BigDog’s control system keeps it balanced, manages locomotion on a wide variety of terrain, and does navigation. Sensors for locomotion include joint position, joint force, ground contact, ground load, a gyroscope, LIDAR, and a stereo vision system. Other sensors focus on the internal state of BigDog, monitoring the hydraulic pressure, oil temperature, engine functions, battery charge, and others.