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Artificial Retinas Can Balance a Pencil On Its End
mikejuk writes "A team of researchers has built a neural information system that is good enough and fast enough to balance a pencil in real time. If you think it's an easy task, try it! The Institute of Neuroinformatics, ETH / University Zurich have used what look like video cameras to do the job but in fact they are analog silicon retinas. They work so fast that even with fairly basic hardware they can balance a pencil."
In case anyone misinterprets your comment.. The fact that it is incompatible with the last decade of computer vision doesn't make it wrong, nor does it make the previous decade of research in computer vision wrong. As you wrote, different philosophies behind the solutions.
... that balancing such an object requires the use of several fancy algorithms:
This is proof that, just exactly as I asserted, all you need is relatively simple feedback as long as it's fast enough.
Yep, that was me. I guess I should go back to my MIT professors and let them all know that they're full of hooey. I've sure been shown up by Jane Q. Public!
Or, on the other hand, I could look at the video these fellows provided. Doing that, I might notice that the system is barely stable, very noisy, does not deal with perturbation very well, and accumulates error. I could then read the paper and see, under the section called "VI Control System" it explicitly states that they are using a PD system (proportional and derivative), as described in the system of two differential equations. Then I could read the sentence, "Our system normally balances an object for several minutes before losing it..." which would probably be because they don't have an I term to worry about accumulating error. Lack of an I term makes the system drift, and you can see in the video that it nearly hits the edge of the actuator workspace a few times. Striking the limit of motion would be a catastrophic change in actuator impedance and cause the pencil to be dropped. The fact that they had to include a D term means that there is more than just straight (linear) feedback. But, hey, I guess those MIT professors didn't actually know what they were talking about when they taught us 18.03 Differential Equations. Either that or Ms. Public can't read papers very well, and doesn't recognize a differential equation when she sees one.
Again, I'll state, Ms. Public, please stay away from designing any systems that are critical to support or protection of human life. You have now repeatedly demonstrated your incompetence to do so in a public forum.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
People have been doing this since the 90s. Here is a paper where they say they use a 30 fps camera. I am sure you can find an older one. I saw one in 1996. http://www.manuelstuflesser.net/stuflesser_paper.pdf Also, if you ask CV people they don't think they are part of AI. Some of them use AI, but there are many tools used.