BigDog BigDog is a dynamically stable quadruped robot created in 2005 by Boston Dynamics with Foster - Miller , the NASA Jet Propulsion Laboratory , and the Harvard University Concord Field Station . BigDog is long , stands tall , and weighs , about the size of a small mule . It is capable of traversing difficult terrain , running at , carrying , and climbing a 35 degree incline . Locomotion is controlled by an onboard computer that receives input from the robot ' s various sensors . Navigation and balance are also managed by the control system . History . BigDog is funded by the Defense Advanced Research Projects Agency ( DARPA ) in the hopes that it will be able to serve as a robotic pack mule to accompany soldiers in terrain too rough for conventional vehicles . Instead of wheels or treads , BigDog uses four legs for movement , allowing it to move across surfaces that would defeat wheels . The legs contain a variety of sensors , including joint position and ground contact . BigDog also features a laser gyroscope and a stereo vision system . BigDog ' s walking pattern is controlled through four legs , each equipped with four low - friction hydraulic cylinder actuators that power the joints . " The BigDog robot , labelled as a military robot mule , has subsequently proven its potential worth in its ability to reduce load and remove that burden from a soldier ' s back . " The BigDog project was headed by Dr . Martin Buehler , who , in 2012 , received the Joseph F . Engelberger Award award from the Robotics Industries Association for the work . Dr . Buehler , while previously a professor at McGill University , headed the robotics lab there , developing four - legged walking and running robots . Built onto the actuators are sensors for joint position and force , and movement is ultimately controlled through an onboard computer which manages the sensors . Approximately 50 sensors are located on BigDog . These measure the attitude and acceleration of the body , motion and force of joint actuators as well as engine speed , temperature and hydraulic pressure inside the robot ' s internal engine . Low - level control , such as position and force of the joints , and high - level control such as velocity and altitude during locomotion , are both controlled through the onboard computer . BigDog was featured in episodes of " Web Junk 20 " and " Hungry Beast " , and in articles in " New Scientist " , " Popular Science " , " Popular Mechanics " , and " The Wall Street Journal " . On March 18 , 2008 , Boston Dynamics released video footage of a new generation of BigDog known as AlphaDog . The footage shows BigDog ' s ability to walk on icy terrain and recover its balance when kicked from the side . The refined equivalent has been designed by Boston Dynamics to exceed the BigDog in terms of capabilities and use to dismounted soldiers . In February 2012 , DARPA , which has continued to support the programme , carried out the first outdoor exercise on the latest variation of the LS3 with it successfully demonstrating its full capabilities during a planned hike encompassing tough terrain . Following the success , an 18 - month plan has been unveiled , due to start the summer of 2012 , which will see DARPA complete the overall development of the system and refine its key capabilities , ensuring its worth to dismounted warfighters before it is rolled out to squads operating in theatre . The BigDog must be able to demonstrate its ability to complete a trek within 24 hours without refuelling while carrying a load of , whereas a refinement of its vision sensors will also be conducted . At the end of February 2013 , Boston Dynamics released video footage of a modified BigDog with an arm . The arm can pick up objects and throw them . The robot is relying on its legs and torso to help power the motions of the arm . The news writer supposed it can lift weighs in the 50 pounds ( 23 kg ) range . Hardware . Big Dog is powered by a two - stroke , one - cylinder , 15 - HP go - kart engine operating at over 9 , 000 RPM . The engine drives a hydraulic pump , which in turn drives the hydraulic leg actuator s . Each leg has four actuators ( two for the hip joint , and one each for the knee and ankle joints ) , for a total of 16 . Each actuator unit consists of a hydraulic cylinder , servovalve , position sensor , and force sensor . Onboard computing power is a ruggedized PC / 104 board stack with a Pentium 4 class computer running QNX .