IMU question

[david]

Hi everyone,
How does the Aeroquad estimates pitch\roll? I went threw the software and I can see it doesn't use the kalman filter, but somthing called complimentary filter?
how does the information from the gyros is combind with the information from the accelerometers?
is there a gyro drift compansation?

Is there any documentation?

Thanks!

[ali]

you will be lucky if some1 replies you in detail about this...
no1 replied to any of my questions on this forum till now

it looks like there are "few" people know about this project from the start...and those are the only ones keep testing and posting results among each other...

[CupOfTea]

google knows this link gave me enough for now without frying my brain

[RoyLB]

google knows this link gave me enough for now without frying my brain

That's link has pretty good explanation of a one-dimensional first-order comp filter.

Now, throw in the 3rd dimension:
http://www.freescale.com/files/senso...ote/AN3461.pdf, page 4

And make it second order instead of first:
http://www.rcgroups.com/forums/showt...r#post12082524

And hopefully you'll have enough to understand what the filter is doing.

I do plan to write up some better explanation of the filter code as well as quadrotor dynamics and control in general. I'll probably post it on the rcgroups site, but I'll put a link to the thread somewhere on these forums when I start it.

- Roy