BigDog is a dynamically stable

quadruped Quadrupedalism is a form of locomotion in which animals have four legs that are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four legs is said to be a quadruped (fr ...

military robot Military robots are autonomous robots or remote-controlled mobile robots designed for military applications, from transport to search & rescue and attack. Some such systems are currently in use, and many are under development. The difference b ...

platform that was created in 2005 by

Boston Dynamics Boston Dynamics, Inc., is an American engineering and robotics design company founded in 1992 as a Research spin-off, spin-off from the Massachusetts Institute of Technology. Headquartered in Waltham, Massachusetts, Boston Dynamics has been owne ...

with the Harvard University Concord Field Station. It was funded by the U.S.

Defense Advanced Research Projects Agency The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Adva ...

(DARPA), but the project was shelved after the BigDog's gas engine was deemed too loud for combat.

History

BigDog was funded by the

(DARPA) in the hopes that it would be able to serve as a mechanic 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 be difficult for 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 is long, stands tall, and weighs , making it 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. BigDog's walking pattern is controlled through four legs, each equipped with four low-friction hydraulic cylinder actuators that power the joints. BigDog's locomotion behaviors can vary greatly. 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. The travel speed of BigDog varies from a crawl to a trot. The BigDog project was headed by Dr. Martin Buehler, who received the Joseph Engelberger Award from the Robotics Industries Association in 2012 for the work. Dr. Buehler while previously a professor at

McGill University McGill University (French: Université McGill) is an English-language public research university in Montreal, Quebec, Canada. Founded in 1821 by royal charter,Frost, Stanley Brice. ''McGill University, Vol. I. For the Advancement of Learning, ...

, 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 ''New Scientist'' is a popular science magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organ ...

'', ''

Popular Science Popular science (also called pop-science or popsci) is an interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is more broad ranging. It may be written ...

'', ''

Popular Mechanics ''Popular Mechanics'' (often abbreviated as ''PM'' or ''PopMech'') is a magazine of popular science and technology, featuring automotive, home, outdoor, electronics, science, do it yourself, and technology topics. Military topics, aviation an ...

'', and ''

The Wall Street Journal ''The Wall Street Journal'' (''WSJ''), also referred to simply as the ''Journal,'' is an American newspaper based in New York City. The newspaper provides extensive coverage of news, especially business and finance. It operates on a subscriptio ...

''. In September 2011 Boston Dynamics released video footage of a new generation of BigDog known as AlphaDog. The footage shows AlphaDog's ability to walk on rough 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, with further DARPA support, the militarized Legged Squad Support System (LS3) variant of BigDog demonstrated its capabilities during a hike over a rough terrain. Starting in the summer of 2012, DARPA planned to complete the overall development of the system and refine its key capabilities in 18 months, ensuring its worth to dismounted warfighters before it is rolled out to squads operating in-theatre. BigDog must be able to demonstrate its ability to complete a trail in 24 hours, without refuelling, while carrying a load. 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 could pick up objects and throw them. The robot is relying on its legs and torso to help power the motions of the arm. It is believed that it can lift weights around ."BigDog Throws Cinder Blocks with Huge Robotic Face-Arm"
''

IEEE Spectrum ''IEEE Spectrum'' is a magazine edited and published by the Institute of Electrical and Electronics Engineers. The first issue of ''IEEE Spectrum'' was published in January 1964 as a successor to ''Electrical Engineering''. In 2010, ''IEEE Spe ...

'', 28 February 2013. This work was funded by the

United States Army Research Laboratory The U.S. Army Combat Capabilities Development Command Army Research Laboratory (DEVCOM ARL) is the foundational research laboratory for the United States Army under the United States Army Futures Command (AFC). DEVCOM ARL conducts intramural an ...

and paved the way for integrating manipulators with quadrupeds as found on Spot, the spiritual successor of BigDog. https://www.darpa.mil/about-us/timeline/big-dog

Discontinuation

At the end of December 2013, the BigDog project was discontinued. Despite hopes that it would one day work like a pack mule for US soldiers in the field, the gasoline-powered engine was deemed too noisy for use in combat, and it could be heard from hundreds of meters away. A similar project for an all-electric robot named Spot in 2016 was much quieter, but could only carry . Both projects are no longer in progress, but the Spot was only released in 2020."Marine Corps Shelves Futuristic Robo-Mule Due to Noise Concerns"
''

military.com Military.com is a website that provides news and information about the United States military, service members, veterans, and their families as well as foreign policy and broader national security issues. Founded in 1999, the site has been a divi ...

'', 22 December 2015.

Hardware

BigDog is powered by a small

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a four-stroke engine which re ...

, one-cylinder, engine operating at over 9.000 RPM. The engine drives a

hydraulic Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

pump, which in turn drives the hydraulic leg

actuator An actuator is a machine element, component of a machine that produces force, torque, or Displacement (geometry), displacement, when an electrical, Pneumatics, pneumatic or Hydraulic fluid, hydraulic input is supplied to it in a system (called an ...

s. Each leg has four actuators (two for the hip joint, and two each for the knee and ankle joints), for a total of 16. Each actuator unit consists of a hydraulic cylinder, servo valve, position sensor, and force sensor. Onboard computing power is a ruggedized PC/104 board stack with two computers, one running a

Pentium M The Pentium M is a family of mobile 32-bit single-core x86 microprocessors (with the modified Intel P6 (microarchitecture), P6 microarchitecture) introduced in March 2003 and forming a part of the Intel Centrino#Carmel platform (2003), Carmel no ...

processor running QNX (used for sensor data processing) and another running a Core Duo processor (used for visual data processing).Autonomous Navigation for Big Dog (May 2010)
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Gallery

BIg Dog 1.jpg BigDog 2.jpg BigDog 3.jpg BigDog 4.jpg BigDog 5.jpg BigDog 6.jpg BigDog 7.jpg BigDog 8.jpg BigDog 9.jpg BigDog 10.jpg BigDog 11.jpg BigDog 12.jpg BigDog 13.jpg

References

External links