Google-owned Boston Dynamics got some bad news in the final days of 2015.
After years of development and intensive field trials, the Massachusetts-based robotics company learned that the U.S. Marines had decided to reject its four-legged robotic mule, Big Dog. The reason? The thing is too damn noisy for combat, where close quarters and the occasional need for stealth make excess machine noise a liability.
The setback reminded me of a story another group of robotics engineers told me about the development of their breakthrough machine, a robotic exoskeleton that enables paraplegics to walk and soldiers to hump heavy packs without wearing down. It also reminded me of a powerful approach to solving problems and dealing with setbacks that I've encountered again and again reporting on robotics.
Ekso Bionics, which went public in 2015, invented the first viable untethered exoskeleton, one that doesn't need to be plugged into an external power source. Their achievement rests on one engineering breakthrough in particular, and to arrive at it Ekso's engineers had to do something that's surprisingly difficult but incredibly instructive for non-engineers--they had to change the way they thought about their problem.
In the early 2000s, the engineers that would go on to found Ekso were working in UC Berkeley's Robotic and Human Engineering Lab under a DARPA grant. DARPA had funded more than one exoskeleton project (the military really wants robotic soldiers) so the threat of being down-selected loomed over each phase of development. Berkeley's exoskeleton began coming together quickly. It was a massively powerful machine that drew on the most advanced robotics research of the day.
But as the engineers began testing various components in isolation on a workbench, they realized their device would be too power-hungry to work off batteries, an Achilles heel of many robots at that point. Scrambling for a workaround, they started looking at internal combustion engines. The engineers tracked down a Czech man who was legendary in the remote control airplane community for crafting small and extremely powerful engines for racing, which he made himself in a home garage.
It was a promising fix to the power problem: The engine was small enough to mount to the back of the exoskeleton and powerful enough to run a portable electric generator. But there was a downside: The piercing scream of the little engines meant that serious ear protection would be necessary for anyone standing within a hundred feet of them. With the power source spewing exhaust, the team also found out the hard way that it wasn't suitable for use indoors.
It so happened that one of the engineers had a brother who was a Navy SEAL. Proud of the exoskeleton he'd helped create, the researcher gave his brother a sneak peek. The response? Laughter and incredulity. The Berkeley team was hoping its technology would eventually find use in combat zones, but the SEAL had some bad news: No branch of the service would ever invest in wearable tech that was noisy, smelly, and exceedingly heavy. It's a lesson Boston Dynamics probably wishes it learned sooner.
So what did the engineers do? Well, first they panicked. Then one of the engineers, Russ Angold, decided to look at the problem from a fresh angle. Trained as an agricultural engineer, Angold was accustomed to thinking about challenges in a more pragmatic way than his lab-chained partners.
By now the team had invested countless hours trying to find an engine that was powerful enough and portable enough to run their suit, which required massive amounts of power just to stand in place. Angold pressed the mental reset button. What if the robot could keep itself upright completely passively, using no power at all? By only using power to actively take steps, the system would require a fraction of the power.
Following that line of inquiry, the team started looking at unpowered prosthetic limbs, which passively transfer the weight of a person to the ground. That was the breakthrough. The engineers scrapped months of work, started from scratch, and--after lots of trial and error--created a suit that drew no power except during active work. The resulting device was lean enough to run on batteries, solving the noise problem.
The technique Angold used, which is deceptively tricky to deploy because of the blind spots we all have when confronted with challenges, is called inverting the problem, and it's a strategy that's taught in many engineering programs. It's one you should add to your arsenal. Instead of endlessly chasing a solution to the problem you have, ask yourself if there's a way to change the parameters of the problem. You can spend months trying to find a better internal combustion engine, but the biggest breakthrough will come when you figure out how to do away with the engine entirely.
The brilliant engineers at Boston Dynamics know this, of course. Bring on the stealth mule.