How AHRS MEM’s Work

[Ironflight]

I am a believer in the idea that (especially in the experimental world) pilots should know how their systems work - not just how to work them. Just about everyone is flying with MEM’s (solid state gyros and accelerometers) these days - in their EFIS’s, iPads, and phones. This video is a really good explanation of how they actually work.

https://youtu.be/9X4frIQo7x0

It’s either that, or pure magic - and I’ll accept either explanation….

Paul

 

[FinnFlyer]

Truly amazing.

Raises the question: being mechanical devices, how long do they last?
Especially the gyros that are vibrating. Fatigue of a silicone strand?

Normally I think of semiconductors lasting forever (when not overheated or otherwise abused).

Finn

 

[Waiex-guy]

Finn. That’s a very astute observation. I hope someone has some sense of an answer.

Gordon

 

[blaplante]

I picked one basically at random.
Datasheet: https://www.mouser.com/datasheet/2/389/i3g4250d-1849471.pdf

Nothing mentioned of lifetime, however I did notice the maximum shock rating:
10,000 G over 1/10,000 of a second. Impressive. However, dropping it on the floor, might do that.

https://www.tronics.tdk.com/inertial-sensors/high-stability-digital-mems-gyro/
Notes MTBF (mean time between failure) of over 1,000,000 hours.

Glad to make some use of my EE degree once in a while ;-)

For something that affects all of our modern electronics, check out tin whiskers... https://nepp.nasa.gov/whisker/background/index.htm these little devils like to grow inside circuits.

 

[planenutz]

That was very worthwhile watching - thanks Paul.

It's quite increadible how humans have created and adapted these technologies. I would imagine these 3 dimensional sensors are not only several kilograms lighter than those used on board the Space Shuttle but also significantly more reliable too.

 

[Desert Rat]

Thanks for sharing Paul, that was amazing.

We talk about how fast technology is advancing and changing, but this drives home the point that it really isn't new ideas that causes it, but rather advances in manufacturing capabilities. Even the ability to create those ridiculously complicated visual aids in just a week. Wow.

 

[FinnFlyer]

I picked one basically at random.
Datasheet: https://www.mouser.com/datasheet/2/389/i3g4250d-1849471.pdf

Nothing mentioned of lifetime, however I did notice the maximum shock rating:
10,000 G over 1/10,000 of a second. Impressive. However, dropping it on the floor, might do that.

https://www.tronics.tdk.com/inertial-sensors/high-stability-digital-mems-gyro/
Notes MTBF (mean time between failure) of over 1,000,000 hours.

Glad to make some use of my EE degree once in a while ;-)

For something that affects all of our modern electronics, check out tin whiskers... https://nepp.nasa.gov/whisker/background/index.htm these little devils like to grow inside circuits.

114 years of continuous use! I guess I can live with that.

I'd forgotten about whiskers. Wonder if conformal coating on circuit boards prevents that. Of course whiskers inside a chip or thick-film device may happen?

So long-term reliability of solid state devices or circuits is not a given

 

[PilotjohnS]

Nerds Rule

1. Nerds Rule; Changing the world quietly
2. I hope the inventors own RVs with Garmin Suites!