"Your phone knows its position in space"<p>Mistakes happen, but in a video about gyroscopes it's hard to forgive mistaking position and orientation. That's the kind of thing that warrants a delete and re-upload.
Later in the video it correctly uses ‘movement in space’ (showing changing (x,y,z)) and ‘orientation’ separately when talking about use of accels and gyros respectively. The ‘position’ in the introduction is glossing over this before getting into details. You could argue with the presentation decision, but it’s not ignorance.<p>The video talks about accels in a few places, and how they are required for pose estimates.
Doesn’t the phone need to know the orientation to measure the position (along with acceleration and possibly magnetic field strength and dir)?
It's the new age of illiteracy. Few people seem to care about the fact that words have meaning. I cannot be the only one noticing a downward trend here and I'm talking about real life and not some social media slop discussions.<p>On this note, thank you for pointing it out.
The gap is so small that a bacteria could easily fit between them.
My garage is so small that a bacteria could easily fit inside.
I recently purchased the S3 Stick from M5Stack.<p>It's an ESP32 with:<p>- microphone and speaker<p>- wifi<p>- bluetooth<p>- screen<p>- two buttons<p>- IMU with six dimensions<p>all for under $35.<p>You can see a video of me using it to control a web based mini plane simulator
<a href="https://x.com/alexpotato/status/2109782226841870352?s=20" rel="nofollow">https://x.com/alexpotato/status/2109782226841870352?s=20</a><p>Wild how cheap this kind of stuff has gotten.
They are so cheap that you can put them <i>in</i> the moving parts of a robot instead of just in the body now.
Economies of scale, isn't it? They are used in billions of devices.
A few things about MEMS devices I have not been able to figure out is:
1. Is the sensing/moving structure actually disconnected from the rest of the device?
2. If so, how does it not get stuck to a side?
3. If it isn't disconnected, doesn't the friction from the connection cause an offset in the reading?
4. How do they etch the structure so that it is disconnected from the layer below?
I believe the answer to your question is that the structure is "connected" to form a solid piece of material, but like any real material it isn't perfectly rigid. So it can vibrate, kind of like a tuning fork, and the thinner parts can act as springs. See the diagrams here: <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9571586/" rel="nofollow">https://pmc.ncbi.nlm.nih.gov/articles/PMC9571586/</a><p>If you wanted to use such a device as a simple oscillator, you just set it vibrating and measure the oscillation frequency. Since the material isn't perfectly elastic, the vibrations will eventually be damped and die out (I guess this is what you mean by "friction"), so you use a feedback mechanism to keep the oscillation going.<p>A gyroscope works the same way, except that you use feedback to maintain an oscillation in one axis, and measure how much of that oscillation couples to a different axis. Whatever effect the damping has on the final measurement, I would assume it can be easily calibrated out.<p>I don't really know how they physically manufacture these devices without damaging the tiny, delicate structures. It's kind of mindblowing that they're so incredibly cheap.
1. Not entirely, it has two degrees of freedom. Think of it like a bridge.<p>2. The opposing springs are normally in equilibrium, so in the absence of forces the center mass moves back to position zero.<p>3. Think of it like a bridge. The points of contact and support are to the sides and stationary, while the spring mass system is suspended in air or in a vacuum.<p>4. Is simple enough if you start with two disconnected layers of materials, and then etch the top layer. You could also start with a layer of something like photoresist spincoated on the bottom layer, except for the adhesion points...<p>An interesting real-life scenario was the possibility of helium atoms being able to get inside the MEMS clock of some smartphones and cause the phone to stop working until enough helium can escape.
It would explain why every smart phone I have ever owned has gotten stuck in landscape until I shook it hard enough.
I was going to share this with my kid, but then the video turned into an advertisement for "war thunder" a free videogame.. no thanks
this is wild i literally did not realize we had them so small at this point
It's cool'cause there's a commercial baked into the middle of it.
"How" Gyroscopes Got So Small.<p>God, I so hate the auto-title "fixing" feature on HN.
I wonder why it's still here after all these years? It seems both useless and harmful, one of those features whose lifecycle consists of someone rolling it out because of some idea they had and then removing it three hours later after having to fix multiple headlines because they didn't think it through.<p>What is it even supposed to do?
god DANG it
I don't have time to watch the video but I was curious why MEMS gyros were shaped thus. Apparently it is to maximize sensitivity through the Coriolis force.<p><a href="https://en.wikipedia.org/wiki/Vibrating_structure_gyroscope" rel="nofollow">https://en.wikipedia.org/wiki/Vibrating_structure_gyroscope</a><p>Their peculiar geometry reminds me of computer-designed antenna.<p><a href="https://en.wikipedia.org/wiki/Evolved_antenna" rel="nofollow">https://en.wikipedia.org/wiki/Evolved_antenna</a>
and we get to use their outputs in any app we develop!
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Thanks! I didn't watch the video yet but their YT channel rocks. Subscribed. :D