IMU aligneament algoritm

[GoogleCodeExporter]

I am testing the APM, but i found the aligneament algoritm of the IMU
is essentially wrong.Let me explain:
I'm a professional pilot and in every aircraft the aligneament of the attitude 
gyro is accomplished regardless of the ground leveling.
When i turn on the avionics if the aircraft and it is off level the attitude, 
when erected, will indicate the real attitude relative to the gravity vector.If 
i turn on the APM a little bit banked it will assume that bank as zero and it 
is wrong because you need a precision leveled reference surface each time you 
turn on the APM.My suggestion is to try to modify the firmware so the 
aligneament will be accomplished assuming the gravity vector as reference.
Thanks in advance. 

Original issue reported on code.google.com by stevefor...@gmail.com on 27 Apr 2011 at 5:51

[GoogleCodeExporter]

We can easily do this.  However, we have chosen not to for performance reasons. 

Please remember that we are dealing with an inexpensive piece of hardware here, 
not commercial avionics with a $XX,000 price tag.  The accelerometers we use 
are not particularly stable over temperature, so if we just use a calibration 
based on a single temperature there will be performance issues when operating 
at significantly different temperature.  The temperature characteristics have 
not been shown to be consistent enough from device to device to build in a 
general temperature compensation algorithm.

Original comment by dewei...@gmail.com on 30 Apr 2011 at 8:28

• Changed state: WontFix