Re: [Paparazzi-devel] Temperature compensation of rate sensors

[Felix Ruess]

Hi,

gyro bias drift due to temperature should not be a real problem with ahrs int_cmpl_quat since the bias is estimated when running.

And at startup the initial gyro bias is set through the AHRS aligner...

However if the sensitivity changes with temperature it could become a problem.

Also bias (drift) of the accelerometers might be a problem, since this is not estimated by the complementary AHRS.

But compensating for bias drift due to temperature directly is of course always nicer than estimating the bias. But you usually need to calibrate this yourself with a more or less elaborate setup...

Cheers, Felix

On Thu, Mar 14, 2013 at 4:12 PM, Prof. Dr.-Ing. Heinrich Warmers <address@hidden> wrote:

Hi,
i made a new warm up experiment:
                     accel.      x y rate  last temperatur of the die  x 62,510E-10   in Volt  4mV/°C
20,6°C    x  26310    21808
                y   26680   21620
                z  31710    18081 temperature of the IDG500

25°C         26307       21841
                 26673       21598
                 31680       18350

30°C        26280         21870
                26648         21555
                31645         18620

35°C      26248          21902
               26650         21502
               31577         18908

40°C      26230            21959
               26641           21446
               31523           19200

Therfore we get   for the accerlatiometers
x     -4/°C
y     -1.95 /°C
z     -9.35 /°C

and for the rate sensors

x    7.55/°C
y   -8.7/°C

I think that a impementation  of  bias  correction will   help.
Six constants  multiplication's  and addition's

Heinrich.
 


Sergey Krukowski schrieb:

I don’t have much experience with the latest paparazzi DCM ahrs, but worked with the initial dcm implementation and actually came to the same solution – measuring and modelling the rate sensors temperature drift. But the solution is really annoying, needs lot of handwork.

Have you tried the cmpl_quat ahrs? There is also of centrifugal force compensation implemented and from my experience (based however on rotorcrafts basically) works well. If you are sure you don’t have significant accelerometer drift could carefully try it.

 

Regards,

Sergey

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