By DAVID AXE
It was a deal nearly three years in the making. In 2007, Massachusetts-based defense giant Raytheon announced its acquisition of tiny Sarcos, a technology firm operating out of a single facility in Salt Lake City, Utah. “With Sarcos, we are gaining world-renowned research and development capabilities in robotics technology,” said Dan Smith, president of Raytheon Integrated Defense Systems. …
The first two technologies likely to transition from Sarcos’ labs to Raytheon’s factories are a wearable, robotic exoskeleton meant to boost soldiers’ endurance and lifting ability and a small, multi-purpose robot that combines the qualities of a snake and a tank.
An early incarnation of the snake ’bot has received some press, but Raytheon and Sarcos have kept quiet about recent, major improvements to the design, until now. The Mark II version of Sarcos’ snake ’bot is tougher and simpler than its predecessor, and closer to being field- and production-ready.
The impetus for developing a military robot modeled on a snake originated in the Defense Advanced Research Projects Agency, or DARPA, the Pentagon’s fringe science wing. DARPA has long been interested in novel robot forms inspired by nature, especially for traversing tough terrain. In 2004, the agency expressed a desire for a “serpentine” search-and-rescue robot capable of “overcoming obstacles that are a significant fraction of its length, crossing slippery surfaces, ascending poles, climbing steep slopes and optically sensing its immediate surroundings.” DARPA labeled it a Multi Dimensional Mobility Robot, or MDMR.
With DARPA’s encouragement, a number of organizations devised new, prototype snake ’bots. (It’s worth pointing out that rudimentary serpentine robot designs have existed since the 1980s.) Most notably, roboticist Dr. Howie Choset at Carnegie Mellon University developed his Modular Snake Robot, pictured. By 2006, Choset’s three-foot-long robot was capable of scaling vertical poles in demonstrations.
At first, Sarcos simulated a similar approach to its MDMR snake, with a five-foot-long, segmented body, weighing 15 pounds and designed to grip terrain and obstacles. For locomotion, this kind of snake robot can roll, slither or “inch” like a caterpillar. It’s adept at crossing rubble, sand and tall grass and scaling ladders and stairs. But progress was slow on such a design, [designer Stephen] Jacobsen tells Unmanned Systems. “It’s complex locomotion you’ve got to understand gaits.”
“All of the sudden, time got short and we realized it’s not going to be practical if it got that much more complex,” Jacobsen says. So Sarcos’ design team shifted gears. The result was a hybrid system, with the general shape of a snake, including a segmented body, but with small, tank-like tracks on the ends. “We realized, with a track at either end and seven degrees of freedom [between segments], we can do a lot of things.”
Those things include “shape-shifting” to adapt to terrain. While Sarcos’ hybrid snake ’bot can slither like its “pure-bred” kin, it can also twist into a rigid U shape and roll on its treads like any of today’s most popular tracked robots. The hybrid has also proved adept at a maneuver Jacobsen calls “the cobra,” which has the robot raising its “neck” straight into the air to peer around at its surroundings. For eyes, Sarcos’ snake has two optical sensors: one for the operator (who controls the robot using a wired controller) and another for a commander.