Travel speed of BigDog varies from a 0.45 mph (0.2 m/s) crawl to a 3.6 mph (1.6 m/s) trot. It can stand up, sit down, walk with a crawling gait that lifts one leg at a time, walk with a trotting gait lifting diagonal legs, or trot with a running gait. BigDog's locomotion behaviors can vary greatly. Navigation and balance are also managed by the control system.īigDog's walking pattern is controlled through four legs, each equipped with four low-friction hydraulic cylinder actuators that power the joints. Locomotion is controlled by an onboard computer that receives input from the robot's various sensors.
It is capable of traversing difficult terrain, running at four miles per hour (6.4 km/h), carrying 340 pounds (150 kg), and climbing a 35 degree incline. BigDog also features a laser gyroscope and a stereo vision system.īigDog is 3 feet (0.91 m) long, stands 2.5 feet (0.76 m) tall, and weighs 240 pounds (110 kg), making it about the size of a small mule. The legs contain a variety of sensors, including joint position and ground contact. Instead of wheels or treads, BigDog uses four legs for movement, allowing it to move across surfaces that would defeat wheels. Image from the DARPA Strategic Plan (2007) īigDog was funded by the Defense Advanced Research Projects Agency (DARPA) in the hopes that it would be able to serve as a robotic pack mule to accompany soldiers in terrain too rough for conventional vehicles.