Can Repelling Magnets Replace the Spring in a Pogo Stick?
kjmagnetics.com
kjmagnetics.com
Inifinity tried steer-by-wire but ended up retrofitting traditional hydraulic steering back.[1]
That said there are probably 5-20 systems in a car that can completely control these systems without any human input. Think of automatic emergency braking, traction control, vehicle stability control for the brakes, and autopark + powered steering for the steering.
Most of these systems have multiple redundancy and isolated monitors (eg, if autopark is on and the vehicle speed is > 10mph, the monitor will intervene) but there are still probably some theoretical situations where this could occur
Which is why you see headlines like: "Skyscraper elevator plunges 84 floors — and everyone survives" https://www.cbc.ca/news/world/elevator-plunge-chicago-1.4913...
Note that it wasn't descending particularly quickly; one cable snapped but other safety systems were still operable.
So, 500 feet of freefall is still substantial. That puts the situation on par with a bungee jump.
What I never understood is how elevators can travel downwards so quickly without such a system engaging. Can they block it somehow or are they never accelerating fast enough down?
Apparently if that ever happens, your best bet is to lay flat on the floor with your hands covering your head, as the impact will launch you upward.
(military jets have been so longer).
Apart from being hit with a high-explosive anti-air missile, I can't think of any failure mode in a plane that has such a narrow recovery window.
Reliably implementing image recognition from multiple cameras and AI that should respond to ever changing weather, inconsistent roads, signs, maps and other human drivers erratic behaviour within milliseconds - Not even in the same league.
Not saying aircrafts are simple but self driving is just orders of magnitude more complex. Otherwise we would have seen them on the roads already.
Aircrafts also have much stricter maintenance schedules, failure investigations and completely different economic, media and moral incentives.
I’ve had it lose tracking on the highway. It just leaves the wheel in the last position and beeps very urgently to let you know to take over.
I find autopilot helps me become more aware and less fatigued while driving. It’s a level 2 system. There is never a question of losing engagement as an active driver like what happens with level 3 self driving.
It will keep a clearly marked lane better than I can (it’s very precise with staying in the exact middle of the lane and doesn’t cut corner like humans tend to). For stop and go traffic it’s a blessing.
It sucks at zipper merging. I’ve had to brake for merging cars more than once, even though they are visible coming into my lane on the HID. That part needs work. And I don’t really trust it to change lanes as I feel like the blind spot detection isn’t quite there either.
All said it’s pretty much the most amazing driving tech ever, and the TM3 is most definitely the most amazing driving machine I’ve ever had the pleasure of owning. Just orders of magnitude better handling than I realized was possible. Curves rated at 25mph that I used to take at 45mph in my Infiniti previously with some tire squeal, it can silently tear through at 65mph. I don’t know what the skidpad rating is, but it feels unflappable and body roll is just nonexistent.
Actually it’s a bit tricky because you literally feel no complaints or judder or roll all the way up to pulling 100% of traction the tires have to offer. It is quite well mannered once it does start drifting though.
Sorry, sorry, I can’t help it. You can guess I’m thrilling at parties.
They factor how far a head you can see, and how much time you need to react. Lots of cars/bikes can obviously tear through them faster. But that means they are just taking much more risk.
That said, perhaps auto driving can respond quicker, but I’d imagine that doesn’t change most of those ratings give. The time needed to avoid accidents is largely due to physics not reaction speed.
Anyone have experience with the lower Westchester County section of the Taconic Parkway? There are some serious curves, and the lanes are very narrow. In the left lane, you're maybe 2-3 feet from the box-beam center divider.
Right? I have an irrational fear of laser eye surgery because I'm afraid some random component in the machine will fail and cause some sort of over-powered pulse.
It's far more realistic a component would fail in a car though and cause the 'brain' to take a shit on itself. Still pretty out there but it would be a very real concern of mine.
As far as bugs go, you could clamp the output in the good old fashioned analog way (i.e. via circuitry) so the worst case is you just fall/jump off which is already the case for the sprung ones.
...edited for sense
No, you're riding a coil gun. But your point stands.
> As we add more magnets to the stack, the maximum pull force alternates up and down. If 2 magnets repel with some force, 3 is a little less, but 4 is a little more 3, but 5 is a little less than 4, etc. Why is this so?
Shouldn't these guys have figured it out pretty easily? Both seem to be readily explained by the fact that it's not just the adjacent pairs of magnets that interact. Given magnets ABCD, the A magnet is repelled by B and D but attracted by C. B is equally repelled by A and C, but attracted by D. And so on.
You could try A BC D, AB CD, AB C DE and A BCD E.
Elastomer bumper should do the trick.
YouTube has the advantage of being able to preprocess the audio track in its entirety, although most implementations work on a block basis and don't need that. A 'night mode' feature would take about one weekend's worth of work from start to finish.
You would also need a fairly sophisticated content detection system (don’t distort anything that is music, which is a huge use case on YouTube for example).
No, you need a button that the user can press to turn the feature on and off. It should default to 'off.' For extra points, make it a slider.
Not to mention adding _any_ steps to their intake pipeline requires more processing power and data moving than you and I will ever touch in our lifetimes.
Compared to the work needed to process the video itself, it would be a total non-issue.
On the server side, they could maintain a separate compressed audio track and switch to it when requested. They should have the ability to do that anyway for alternate languages and commentaries and such. Whether it would be more cost-effective to maintain a separate set of compressed tracks or to decode/compress/re-encode on the fly, I don't know.
It might be tempting to maintain caches of compressed tracks created on demand. That way they'd almost never incur a runtime penalty on the server, and also wouldn't have to pay a lot for storage. More than a weekend's worth of work at that point, though.
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As long as the open-wide distance is capped you should have a smoother distance-energy diagram.
I think you're making things too difficult and expensive if you're trying to magnetically suspend and stabilize the pogo stick in multiple/all directions.
Also, magnetic radial stabilization would be stable only in a rough sense. The pogo stick handle would still wobble and be disturbingly/unexpectedly unsteady. I think for pogo sticks you'd really want a mechanically confined, piston-like design. You could still have magnetic stops on both extremes.
Another advantage of my design is that it allows (requires, in fact) one to use many small magnets in place of a few large ones, which is safer and easier to engineer. But as for expense - I think that once you decide to replace springs with magnets in a pogo stick, you have left the path of economy anyway and might as well go for broke.
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The pairs could then repulse each other at a closer distance, approximating the spring function. I accept royalty donations :-)...but it's probably patented by now.
https://uwaterloo.ca/motion-research-group/publications/kine...
Keys itself return into their normal position because of gravity, but part of key action mechanism was powered by a spring. I discovered it while trying to fix some keys which was too slow to "recharge", to return to a normal position after a soft note, so I was unable to make a sequence of a short duration soft notes from the same key. I fixed it by stretching springs long enough for a plastic deformation to occur. Loud notes worked ok, because their "recharge" was driven fully by springness of the strings.
Though it was just one piano, I do not know how different the mechanics can be between different pianos.
That said, the 3 magnet configuration would be:
NS - SN - NS
From the article:
> We added a third magnet, alternating which way the polarity faces with each magnet. Each magnet repels any adjacent magnets.
For small separations, the exact geometry of the magnets starts to matter. http://www.magnetsales.com/design/faqs_frames/FAQs_2.htm has some experimental results that show the field going up a bit over 3x when distance drops from 1 to 0.5, then ~2x when going to 0.25, then ~1.5x when going to 0.125 and only changingby 1/8 when going to 0.063... all distances in inches from _surface_ for a magnet that's radius 0.5 and length 0.5 in the same units. Note that this means that the distances from the _center_ are approaching 0.5.
All that said, the force is almost certainly not exponential, I would guess.
In real life it should be pretty close to linear, but it would be worth checking as I could imagine there being non-linearity or time dependence of a spring under what is probably a decent amount of load being applied quickly and repeatedly.
You could "linearise" an electromagnet with distance sensors and code, but that's a bit of a Franken-Solution - not least because any delay in the closed loop could make the system unstable.
In this case a couple of minutes of research - or maybe asking a physicist - would have saved a lot of essentially rather pointless tinkering.
I mean - if you enjoy tinkering more than you enjoy producing an elegant solution, then tinker away. But this is noodling around for the sake of it, not solid engineering.