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Comment by flyinglizard | Hacker News Reader

After seeing the bird defecating on their kitchen counter, I decided this would be the perfect thread to ShowHN my latest creation: a 3 axis gimbal stabilizer for those not lucky enough to have cooperative avians. It's electromechanical, not biological, so don't get your hopes up.

https://vimeo.com/81292853

The video shows a synchronous split screen of the very same flight, with an unstabilized GoPro on left half and a stabilized one on the right half.

(other than the aircraft and the camera, everything there is self developed: firmware, hardware, gimbal mechanics)

Some more videos here: https://vimeo.com/user22741569/videos

View on HN

FYI the audio is distracting, consider blanking it out and replacing with silence.

The gymbal is pretty effective, do you use a 6DOF system to provide the feedback? I have a system that I had hacked together with a 3 axis accelerometer and never could get it critically damped to the point where you wouldn't see some oscillation in the view. I speculated that if you had a gyro as well you might be able to use the magnitude of the gyro signal to tune the feedback loop with the accelerometer such that you could keep it critically damped over a wider variety of changes in orientation.

There are other such systems as you describe using 6DOF (like Alexmos, used in many DIY projects and commercial handheld gimbals), but none get to this level of performance. In particular these systems develop a lot of horizon drift under lateral loads affecting the accelerometer. Our system can be configured to use up to 19DoF (that's 9DoF x 2 sensors, and a barometer), which is partially the reason for the performance you see here.

One software suggestion. Have an option to put in an orientation tracking factor so you can have the PID loops slowly track the aircraft if desired. In some cases you want a perfectly level flight, but in others you want to have the feeling of flying smoothly with banks and all. It would allow you to dampen out all the craziness of quad flight, but still see majestic turns and such.

Wow, I never realized how the obnoxiousness of camera shake and rolling shutter combined to make something even worse than simply adding them.

Oh yes, you're talking about the dreaded "GoPro Jello". At specific vibration frequencies, the entire image begins to move around. We're doing lots of signal processing to counteract that.

Any chance you might sell this? I can imagine lots of uses for this tech.

Yes, it's going on the market pretty soon. If someone wants to talk, roee ಠ phobotic.com

I don't think that ಠ is supposed to be there.

It's my middle finger to the spambots. I figured they already have workarounds against all the permutations of '- at -', but no way they've thought of that one.

Of course, many people probably wouldn't have a workaround to that one either, alas.

Point made - I've put it through an accessibility enhancement.

I am definitely using that from now on.

I just use gmail. It blocks spam without requiring people to solve a puzzle in order to contact me.

Up until recently - I would have agreed with you. I just find I'm getting spam much more regularly now on my Gmail account.

it always made me wonder why computer literate people obfuscate their email in such a way that a single regex could pickup about 99% of them.

personally i don't obfuscate my email at all - good spam filtering is much more effective than trying to hide your email address.

The fact that most credit card entry fields don't accept spaces gives me hope that most spambots can't turn " at " into "@".

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