EPThttp://ieeexplore.ieee.org/document/1272198/?reload=true
Also, found this cool video of a double pendulum on a cart (not the dual one you describe, but cool nontheless!):
Ask and answer stupid questions here! - Page 678
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Deleuze
United Kingdom2102 Posts
http://ieeexplore.ieee.org/document/1272198/?reload=true Also, found this cool video of a double pendulum on a cart (not the dual one you describe, but cool nontheless!): | ||
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Thouhastmail
Korea (North)876 Posts
I know it sounds a bit weird; what's your opinion about this? | ||
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Dangermousecatdog
United Kingdom7084 Posts
On November 04 2017 10:19 FiWiFaKi wrote: Is it possible to build a feedback mechanism that can balance two completely independent inverted pendulums on a single surface? If so, what would the limit of independent inverted pendulums that can be balanced by one feedback loop be? This video here got me thinking: https://recordsetter.com/world-record/balancing-two-poles-head/36029?autoplay=false My head says if the perturbations are small, and they all have different inertias, infinitely many should be able to be balanced, but no real way to prove it. If a human can do it on his face I don't see any reason why a robot face with 6 degrees of motion cannot. That video from Deleuze is really cool. | ||
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Simberto
Germany11522 Posts
If we have two pendulums, and A requires correcting into the positive direction while B requires correction into the negative direction, we have two possible reactions. If we correct into direction +, A becomes more stable, but B has been moved even further from the equilibrium state, and thus requires an even larger correction into - direction. Which again destabilizes A further than it was destabilized before. If any time passes during this, any destable pendulum destabilizes even further into the direction it was already out of whack. To me this sounds like a situation that inherently breaks down rather quickly. Correction into direction - has the same effect with reversed pendulums. My guess is that the guy in the video used the fact that his face can be angled, so he can have different effects on the bases of the two pendulums. Which would mean that you can balance exactly 2 pendulums on one surface if you can also change the angle of that surface and their base points are not the same point, but no more. On November 04 2017 21:06 Thouhastmail wrote: I'm working for prosecutor's office as an investigater and about to double as a priest in episcopal church. I know it sounds a bit weird; what's your opinion about this? As long as you are not investigating the church that you priest in, i don't see a problem. | ||
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FiWiFaKi
Canada9859 Posts
On November 04 2017 21:15 Simberto wrote: My guess would be that it is not possible to balance two independent pendulums on one cart. We can simplify it to a onedimensional movement of the cart and thus a twodimensional problem as seen in the video above. If we have two pendulums, and A requires correcting into the positive direction while B requires correction into the negative direction, we have two possible reactions. If we correct into direction +, A becomes more stable, but B has been moved even further from the equilibrium state, and thus requires an even larger correction into - direction. Which again destabilizes A further than it was destabilized before. If any time passes during this, any destable pendulum destabilizes even further into the direction it was already out of whack. To me this sounds like a situation that inherently breaks down rather quickly. Correction into direction - has the same effect with reversed pendulums. My guess is that the guy in the video used the fact that his face can be angled, so he can have different effects on the bases of the two pendulums. Which would mean that you can balance exactly 2 pendulums on one surface if you can also change the angle of that surface and their base points are not the same point, but no more. As long as you are not investigating the church that you priest in, i don't see a problem. I don't think so. It's all about the response rate of each individual system. When you have a short and long pendulum, the short one will respond (and fall) faster. I imagine it as only focus on balancing the small pendulum, and make correction trends over the long term to prevent the large pendulum from falling. Like imagine you're balancing a ruler on your finger (so you're having to make an adjust every 0.1 seconds or whatever), and then every 2 seconds I tell you to move forward, move to the left, etc. If the response time of the longer beam is and therefore the response time is long enough, this should be no problem in my opinion. When using the small angle approximation, an inverse pendulum becomes: theta_double_dot = (g/l)*theta A double inverse pendulum as in your video is highly non-linear (http://nldlab.gatech.edu/w/images/f/fb/LeeGustavo_Inverted_Pendulum_Final_Report_.pdf , page 3), you need to apply like a 10 trig identities and approximations before you can even get it into the frequency domain with laplace transforms. Whereas the math for what I was asking appears rather easy for only 2 pendulums (http://web.mit.edu/klund/www/papers/CDC03_dip.pdf), but the problem is that they are looking for what compensator works for by inspection and knowledge about what moves the poles in a root locus diagram where. But once you have many different poles there, I don't think you'll be able to do it by inspection anymore. Anyway, I think I'm on the right track, I'll take their math and try to take it a step further and see what happens as I add more. I'm curious about how exponentially the sensitive begins to matter as you add more pendulums. | ||
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AbouSV
Germany1278 Posts
Find a child and go on a segway with him. Push him one way, and let yourself fall the other way. You'll have your answer. | ||
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Sent.
Poland9201 Posts
On November 04 2017 21:06 Thouhastmail wrote: I'm working for prosecutor's office as an investigater and about to double as a priest in episcopal church. I know it sounds a bit weird; what's your opinion about this? Sounds like a tv show script. Make sure you're the protagonist. The other characters tend to die quickly | ||
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Karis Vas Ryaar
United States4396 Posts
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riotjune
United States3393 Posts
Edit:+ Show Spoiler + nvm, you just snort them lol | ||
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JimmiC
Canada22817 Posts
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Simberto
Germany11522 Posts
On November 08 2017 21:58 JimmiC wrote: The drug can, the stuff you put in your bath can not. Two completely different things with the same name. Thanks. I had not realized that these are two different things, which has been really confusing for me. I was working under the assumption that some bath salts in the US contained meth or something like that. This makes a lot more sense. | ||
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farvacola
United States18828 Posts
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GreenHorizons
United States23250 Posts
On November 09 2017 00:09 farvacola wrote: bath salts is just the street name for a variety of different synthetic cathinones that, once upon a time, were sold through online distributors and headshops under the guise of actual bath additives Oh man, I remember when Salvia was supposed to be a legal alternative to weed. I was like "WTF!? They sell this at the corner store!?" (Watch a youtube video about Salvia trips if you don't know). Anyway, how much longer should it take for Michael Slager to be sentenced? He plead guilty in the beginning of May, just wondering how much longer it should typically be before sentencing? | ||
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Karis Vas Ryaar
United States4396 Posts
On November 08 2017 21:58 JimmiC wrote: The drug can, the stuff you put in your bath can not. Two completely different things with the same name. Every crime show I've ever seen now makes infinitely more sense | ||
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jodljodl
173 Posts
On November 04 2017 21:06 Thouhastmail wrote: I'm working for prosecutor's office as an investigater and about to double as a priest in episcopal church. I know it sounds a bit weird; what's your opinion about this? Why does it matter? Since youre an investigator i assume you dont have a problem with deception in general. Why would you have a problem posing as a priest in a church? As long as you dont interact inappropiately with a third party everythings cool imo. If you have to? well simply lie and deceive. Its kinda your job. | ||
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imperator-xy
Germany1366 Posts
https://www.soscisurvey.de/flexiblework/ Takes around 5 minutes, 2 minutes if you are really fast. Didn't know where else to post it, so I hope some people are willing to help us out. The next option would be to use a site where you can buy people who complete it, but we are poor students so that's really the last option. Does anyone else have an idea about where to get people to complete the questionnaire? Thanks in advance to everyone who takes the time to complete the survey or to help us out in another way! | ||
Liquid`Drone
Norway28674 Posts
That said there seems to be some bug? I didn't get past the second screen. Was it because I answered no to all questions and then I'm just not relevant? :p | ||
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imperator-xy
Germany1366 Posts
It has to be like this: Do you work at least 30 hours a week? YES Are you self-employed? NO Do you work as a teacher? NO Otherwise it ends automatically. If you are not currently working, feel free to answer this from the perspective of a job you have held in the past.  Do you need any more respondents? You'd have at least 2 more. :D And btw., thanks for helping! | ||
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Liquid`Drone
Norway28674 Posts
Responding to your survey is right now the closest thing I get to a break from my own writing, lol. | ||
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Zambrah
United States7312 Posts
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