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Re: [Paparazzi-devel] Reply to:"Re: ArduIMU and Tiny autopilot continued
Christophe De Wagter
Re: [Paparazzi-devel] Reply to:"Re: ArduIMU and Tiny autopilot continued (David Conger)"
Wed, 1 Dec 2010 21:25:44 +0100
Does anyone know how fast the gyro integration is done in the arduIMU (Atmel). (DCM propagation)
15Hz attitude data is sufficient for stable flight (slow of fast) but the lower bandwidth sensor also means you need to reduce the gain compared to 60Hz attitude, especially when flying fast (extra phase gives smaller gain margin).
But 15Hz integration is very very low on anything as small and agile as a Funjet. If the weather is smooth enough I do believe this will work, but it's also extremely easy to make is not work anymore by adding vibrations, turbulence, etc...
Even with a very efficient fixed-point implementation, a 20MHz 8-bit micro is "a bit" weak...
On Wed, Dec 1, 2010 at 6:47 PM, Chris <address@hidden>
David i also agree that vibration especially from a not balanced prop
(heavier and/or faster prop makes things worse)
can drive the gyros crazy.
I know this from the helicopters where the smallest vibration can make the best gyro look
I may be wrong but 15 Hz should be enough for a stable aircraft but i don't know what will appen if the wind is strong and makes the plane move around fast.
I will also test the ArduImu in a week or so but i plan to mount the IMU on thick but soft foam
that i used to use on helicopter gyros.
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