Reach, an incredibly endearing short animation movie by award winner, Luke Randall, addresses the very real problem of robot autonomy that roboticists worldwide have been struggling to solve for decades. In the film, a cute robot is left to explore its environment and attempts to overcome the limitations of its depressingly short power cable. Once freed from its restraining leash, the robot only manages to take a few steps before running out of “juice”.
Long have people dreamt of autonomous mobile robots running around, performing routine tasks, not only in our homes and places of work, but reaching out into the unfettered environments of land, sea, air and space. Each of these environments presents its particular characteristics that need to be addressed individually leading to the application of an appropriate power solution. As unlikely as it may seem, it has been relatively easier to provide continuous power to our space-faring, robotic probes and telescopes, through solar panels, than to our humble domestic robots. Closer to home, mobile robots such as Boss, the 2007 Carnegie Mellon University winner of the DARPA sponsored Urban Challenge, celebrates its fantastic autonomy thanks to a traditional diesel fuel tank. Another gas guzzler, this time on four legs, the Big Dog robotic pack mule from Boston Dynamics, derives its power from a two-stroke, one-cylinder, go-kart engine. Its quadruped locomotion system means that Big Dog trades fuel efficiency for the ability to traverse complicated terrain.
Meanwhile, back at the office, mobile service robots have yet to overcome the many obstacles inherent in our human-centric environments, including the regular acquisition of energy from existing power outlets. But, all this may be about to change. The PR2 (Personal Robot 2) robot from Willow Garage, a Silicon Valley robotics research group, not only navigates through non-adapted office environments, but also recharges from standard wall sockets which allows for continuous autonomy. PR2 is not the first robot ever to have plugged itself into a wall socket, but it successfully combines this with powerful navigation and door opening capabilities. The ongoing initiative of the Willow Garage group is to produce a robust open-source, Robot Operating System (R.O.S) that will enable robotics developers, all over the world, to overcome the problems of the past decades and finally let personal robots off their leash.
So far, these robots are designed to operate in specific environments with little need for adaptation from one environment to another. The real problems begin when we envision, for example, humanoids, that can easily navigate both indoor and outdoor environments with a reasonable amount of autonomy. Extensive research is under way in the field of battery efficiency, size reduction and materials towards the goal of near always-on equipment, including robots. A Technology Review article highlights the promising and innovative work of Texas startup, EEstor. According to Richard Weir, the company’s CEO, the breakthrough could revolutionise the world of power usage as we know it. If true, developers of mobile robotics may soon be grinning from ear to ear. And even if ultracapacitor technology fails to solve all problems in this field, the combination with other existing batteries and the advances in nanotechnology will improve the range and efficiency of current robots.
Experimental solutions abound when it comes to powering robots in the “wild”. Whilst fuel cells have been touted as a possible replacement for the currently ubiquitous lithium-ion batteries, the latter can potentially double their output in the near future. So what other ways are researches investigating to keep our robots mobile? This mostly depends on the size of your robot. As we’ve already seen, larger robots can be powered by more conventional means, at least for now. Medium sized robots, such as humanoids fare better with rechargeable batteries and fuel cells with the possible added ability to auto-replace batteries on the go. The tiniest of robots, however, could use bacteria that release electrons as a source of energy and convert kinetic movement to electricity as a result of the piezoelectric effect. Some military robot designs have gone as far as “cannibalising” the readily available fauna in combat zones, converting organic matter into fuel, where other sources are scarce. A flying drone has also been developed, that can “feed” from any nearby power lines by perching on them or hanging from them like fruit bats. All is possible in the pursuit of robot autonomy and reach.
In the future and as materials science improves, advanced robotic creations could be equipped with ultra-efficient, solar-powered “skins” and the provision of power may become wireless. It’s possible and very likely, that a combination of all the above technologies and many yet to be discovered, will contribute to the dream of fully autonomous robots that, unlike the cute robot in the film, can roam freely in our environment.
Tags: Big Dog, Boss, EEstor, future of robotics, personal robots, PR2, Reach, robot autonomy, Urban Challenge, Willow Garage
