[1] The article mentions that they built a quieter version of the robot that carried less. More interesting were problems about how to maintain the things (from training mechanics to supplying replacement parts) and how to integrate them into current training. (How/when to use? Advantages? Disadvantages?)
[2] For those of you interested in the U.S. Military's use of Mules in more recent times: http://www.newyorker.com/magazine/2010/02/15/riding-high
The hydraulic system used is very controllable but not particularly efficient. There's no energy recovery and no springyness; it's brute-force hydraulics. That was reasonable for an experimental machine, but not acceptable in the production product. Atlas, the BD humanoid, has the same problem. It's too similar to BigDog, and weighs about 330 pounds. Schaft, Google's other humanoid robotics company, uses water-cooled electric motors, like Tesla. You can enormously overload electric motors for a few seconds without hurting them, and if you have cooling and temperature monitoring, that works fine. This is probably the way forward for anything smaller than a pony.
Then again just have it "sit". This may not be the best tactically though in small group engagements as "sit" is movement and freeze is dead stop.
I'll let people who know more about that debate it though.
The technology is amazing and will no doubt find use elsewhere.
Google has been against militarizing the robots since acquisition, so they're no doubt happy to have this contract dropped.
To be clear, this doesn't mean the project is shelved, it means the contract with the Marine Corps is shelved. Google will be able to focus more directly on civilian uses for the mules from here on out.
Once the technology is developed by anyone for non-military use, transitioning to the military is easy. There's not some magic that prevents consumer developed technology from reaching the battlefield.
Because money isn't everything?
> There's not some magic that prevents consumer developed technology from reaching the battlefield.
That doesn't mean you're required to actively help it along.
The USMC small wars manual has a lot on how to organise an non mechanized unit that was mostly horse /mule and ox drawn.
Try finding 30 litres of water and 8 kg of grass ( plus a portion of salt ) per mule per day, minimum, in the mountains of Afghanistan.
To move 90 kg of payload? There are many more efficient methods.
We (Air Force Special Operation) used them and horses to great effect in 2001 and the ANA have been using them before and ever since.
http://www.defensemedianetwork.com/stories/operation-endurin...
https://www.washingtonpost.com/world/asia_pacific/for-afghan...
Is it any easier than finding diesel fuel?
[0] http://www.pneubotics.com/
[1] https://otherlab.com/projects
[2] "[...] we're the only game in town." 21:00 onwards https://youtu.be/gyMowPAJwqo?t=1263
Any new inventions that would make their mechanical design steer away from loud hydraulics would no doubt be amazing. However, without Boston dynamics' delightfully ground-breaking controls software design, it'll be dead in the water!
For a little bit of proof, see who they are hiring! http://www.bostondynamics.com/bd_jobs.html
Is there much publicly available information about their software/control design innovations?
Hmm, maybe one might expect they would be hiring more mechatronics engineers to do just that? Or maybe there's still not much point for them because as you mentioned their focus is slightly different currently.
One of the most important things in robotics is reliability, the more work your robot does before breaking down or needing maintenance the more money it makes you. In industrial robot arms the gold standard for this is a Mean Time Between Failures of more than 100,000 hours. That's more than 10 years of continuous operation!
I am skeptical that inflatable robots will be able to last this long. The fabric/elastomer combo is certainly not going to last through 10 years of continuous operation. Sure this part may be cheap, but you still need expensive valving and pneumatics to control said robot. Not to mention that maintenance costs money too. The payback period for robots is also shortening,
The other problem that pneumatic robots suffer from is that air is compressible. This means that moving it around to drive pneumatics is gonna be inefficient and that pneumatic structures aren't that rigid. Higher rigidity means higher resonant frequency which means your robot can operate faster without wobbling around. The inefficiency might be compensated for because the robot is so light, but I have yet to see any hard numbers on this.
This lack of rigidity is touted as a feature by the people who make inflatable robots. Because they are so light and aren't rigid they aren't going to hurt people if they fuck up. There are other ways to solve this problem that are currently used in the robotics industry. One of them is to put a spring on every link in the robot, which is what the Baxter robot does. Another is to make the robot as light as possible and limit speed which is what one of Kuka's human safe robots does[0]. Better control also fixes this problem, if you don't hit the human then you don't have any problem.
But there might be niche applications. Maybe they will find use in the medical field where having anything rigid touch a human is unacceptable or where you need a weird shape to grab a human on a bed. Entertainment might be another, a while back a japanese company made giant inflatable robots for parades.
That's a very good paper. There are many advantages to using two opposed springs driven by actuators to simulate muscles. You get muscle-like properties. You get energy storage and recovery. (Humans recover about 70% of energy from muscle springiness when running. Cheetahs, 90%. BigDog, 0%.)
As that paper points out, there are several ways to do this. The cleanest is a double-ended pneumatic cylinder with proportional spool valves at each end able to connect to pressure or exhaust. That was tried on a legged robot at CWRU some years ago. There are schemes with linear springs, string, two motors, and linkages, which tend to be bulky and complex.[1][2] Those work, but are more of a research design than a production mechanism. Somebody will do a better design, probably with rotational springs and no strings.
I once considered a design with two motors, rotational springs, and a differential. One motor controls impedance, the other controls position. If you don't need to change impedance rapidly, which you usually don't, the impedance motor can be much smaller and geared down.
[1] http://mech.vub.ac.be/multibody/topics/maccepa.htm [2] http://www.inacomm2013.ammindia.org/Papers/106-inacomm2013_s...
If the parts are cheap enough, might it not matter that they don't last the regular MTTF?
One of the arguments I've seen them using is that their robots can actually move faster than regular ones due to their weight advantage - currently I would guess accuracy is not as good though.
Another point I've been thinking about is that biological systems tend to combine the rigid and non-rigid per the needs of the organism, right? It seems that combining these techniques could also be interesting.
The branches are all looking at ways to reduce the load. Pack "animals" are an excellent option to offload heavy equipment and improve the health and long-term mobility of our combat forces.
0: http://archive.armytimes.com/article/20110214/NEWS/102140308... 1: http://www.globalsecurity.org/military/library/report/call/c...
> Resupplying these troops would require more soldiers
> then were actually in the COP...
http://www.nationaldefensemagazine.org/archive/2013/march/pa...
Which includes this quote:
"“What we’ve seen is that when Marines come ashore, they’re carrying 130 pounds of food, water, batteries, ammo, you name it, on their backs because fundamentally, they don’t trust sea-based logistics to keep them supplied,”
Really, as a former soldier myself, the ideal solution is to stop having soldiers and Marines carrying so much damn gear. Much, much easier said than done.
*By ironic I mean "silly ass Marines"
Telling your robot to carry this shit over there is great way to resupply. Compared to having soldiers (or contractors) get blown up driving trucks around.
In most areas where these guys operate, actual mules are probably cheaper, and can be refueled with locally available forage. Not to mention they're more suitable for that kind of environment.
Perhaps more 'extreme' environments where that forage is not available would be more suitable?
We asked a ranger at the bottom. Answer: Helicopter. "They just dangle a huge bag of chat and we cut a hole and walk it along the path letting it pour out. Those mountain meadows are easier to do than the steep stuff at the bottom"
Probably < $1,000 wholesale in off the shelf parts. Def. less than $40mm. Easily carry 100lbs of gear.
Same as this monstrosity. Except it's $39,999,000 cheaper.
Bicycle infantry units have been, and are now a Thing.
"MMRTG contains a total of 10.6 pounds (4.8 kilograms) of plutonium dioxide (including Pu-238) that initially provides approximately 2,000 watts of thermal power and 110 watts of electrical power when exposed to deep space environments."[1]
Even if ~110 watts per ~4.8 kilograms is good for legs in agile situations, as opposed to wheels in a slow-and-steady rover, losing one in combat means you've just given the enemy a few kilos of radioactive material.
[0]https://en.wikipedia.org/wiki/Snow_Crash#Rat_Things [1]http://mars.nasa.gov/msl/files/mep/MMRTG_FactSheet_update_10...
Solar is not an option in practical transportation. The energy yield per surface area is way too low.