[_flux]

A friend has an e-unicycle (I think the category devices has some other name as well..) and he wanted to try out how it behaves in a track.

He sort of knew, but didn't expect it, that when the roll of the device exceeds a certain threshold, the device will shutdown. Even if you're on a curve going with some speed. Broke his wrist. Since then he's also wearing wrist protectors that keep the hand straight.

Actually it was a bit unexpected that it would have known to do that; it must have used its complete IMU data to even know it was rolled, as plain accelerometer would have been pointing "down" as usual.

[leoedin]

I'm an embedded software engineer with past experience developing robotics and motor control drivers.

Those e-unicycles terrify me. No way I'd trust my life to one. Once you're at speed, every failure mode results in instant passenger ejection. I see people flying through traffic on those things - they're just one sensor glitch or integer overflow away from serious injury.

[snatchpiesinger]

> Actually it was a bit unexpected that it would have known to do that; it must have used its complete IMU data to even know it was rolled, as plain accelerometer would have been pointing "down" as usual.

That actually feels like overengineering based on well-intentioned, but wrong specs. You probably want to just use sideways acceleration for "falling over" detection, instead of roll.