The Story of Big Dog – “The Most Advanced Rough Terrain Robot in the World”
Hydraulics in Robotics
Until recently, hydraulics haven’t been particular popular as an efficient system in the development of self-contained, precise robots, especially robots designed to roam land. Generally, hydraulic actuation systems are used in industry to manoeuvre heavy loads. Hydraulics are considered to be a little clumsy, needing pressurised oil to power them; hydraulic systems can be noisy, larger and heavier than their electrical counterparts, they also need maintenance of valves and tubes. These are just some of the reasons why they are rarely considered suitable for mobile robots.
Boston Dynamics however, approached their rough terrain robot with the concept that a hydraulic actuation system would be the most suitable system to deliver their desired result. The developers favoured hydraulics over pneumatics as the pressured air in a pneumatic linear actuator can potentially create an unpredictable bounce effect, which isn’t a side-effect of hydraulics, hence the use of a hydraulic linear actuator. Big Dog’s actuation systems allow the legs of the robot to imitate the legs of a living creature in terms of flexibility. The robot even has identifiable hips, knees and ankles. This means Big Dog is capable of standing up, squatting down, running, crawling and trotting. On top of this, Big Dog’s legs are flexible enough to respond to, and recover from slipping on ice without falling over, much like a human or dog would do.
All the cumbersome compressor systems and computers are stored neatly in the body of the robot, solving the issue of clumsiness sometimes associated with hydraulics. Big Dog has a lot of sensors attached in order to navigate its surroundings, and currently is controlled remotely by a human. You can see a video of Big Dog in action here.
Applications of Big Dog
One of the most useful applications of big dog suggested by the manufacturers is within military situations. Big Dog has the capability to “follow the leader” i.e. follow a human with 2 UV strips on their person without requiring additional GPS or driving from a remote control. This means the robot could carry dangerous explosives at a distance from human military personnel. Likewise Big Dog could be used to scout out difficult to reach areas before the military move in. At present, no robots used in the military have the capability to reach rougher terrain. Big Dog could also be used to plant explosives in the future.
Aside from in the military, Big Dog could be used in search and rescue operations, or to reach people in emergency situations with supplies, when they are cut off from human contact.
Currently, the Boston Dynamic team are working to further improve Big Dog and its capabilities; so really, the possibilities for this robot are endless. It’s a very exciting project and demonstrates how useful hydraulic technology, used in an imaginative way, could be.
The article was written by Ed of Acorn Industrial. Acorn are trusted suppliers of bearings, linear motion products and more! Visit our site for more information!