This robot looks unpredictable and dangerous for any worker that would be in the area. Other point: as a unicycle rider, I would suggest this robot to wear a helmet.
When the engineer is approached he tells the audience that the assistant just switched the robot back to manual for safety reasons.
I think no one could have noticed and I like that kind of honesty. I also found it telling that the people who built the robot have respect for its dangers.
4 wheels can be inherently statically stable but requires more space and requires more energy when running (counter-intuitive, but if your balance algorithm is efficient, you use less energy wheeling around on 2 than on 4 because you can basically play games with gravity to get some acceleration tradeoffs... And you have half the number of powered wheels, assuming you're 4-wheel drive).
If they solve the hard math, the end result may very well be a more performant machine (though as someone else in thread has noted, depending on the overall goals, a zero-wheels statically-mounted arm could be better still).
Whatever BD's angle is, it's not efficiency.
* If the robots need to "reach" for items, you have to figure out balance/stability issues regardless of how many wheels you have.
* The fewer the wheels used, the smaller the footprint of the robot.
Also, recall from freshman physics that the pendulum problem is non-linear. Most balancing robots linearize the problem around the stable point. Which means if the robot gets far away from the equilibrium point, you either have to switch to a different controller or live with the consequences. One of the consequences is the robot racing off to the horizon as it tries to get the wheels under the CG again. (Which may happen anyway whether or not you switch controllers.)
Thus, my standard advice to all newbie robot builders: Your first robot should have a low enough mass that a missing semicolon will not punch a hole in your living room wall.
If this kind of thing is interesting to you, MIT 6.832 Underactuated Robotics by Russ Tedrake is posted on YouTube going a few years back, and the Spring 2019 version is being live-streamed every Tuesday and Thursday, picking up again next Tuesday after spring break.
Static doesn't necessarily mean safer. But the article also notes these aren't intended to share space with humans yet.
They will just have to remove the people to make it more efficient.
https://www.youtube.com/watch?v=EeMTZd68fOU
The robots were above the boxes instead of below the shelves (maybe to beat an Amazon patent? I dunno.) But that warehouse looks like nightmare fuel for a maintenance crew.
> The blaze began high in the warehouse and was so difficult to reach that firefighters had to cut holes in the roof, according to Neil Odin, chief officer at Hampshire Fire and Rescue Service. A sprinkler system only contained the fire in its early stages. It took more than 200 people to quell the flames.