In ArduCopter_2.xx is the barometer still mixed with GPS altitude? I'm asking because we are seeing huge errors in the altitude as soon as we get above sonar range.
We have done two different tests, one with the helicopter flying and one with it not.
1) We take off and fly under stabalize mode and look at the altitude reported in AMP (or Happy Gilmore). When we're under 30 feet the altitude is really locked in, and accurage. It doesn't drift that much either. However if we go up higher, the alititude goes crazy. We will see it jump from 2.0 meters to 12 meters in under a second. And it's hitting all points in between at random. We currently have the ardupilot installed inside the frame of a Logo400 Heli with two layers of felt covering it to cut down on wind.
I would think it was just a problem with a low pressure zone being created by the spinning main gear except for test 2.
We turn the motors off and put the helicopter in our truck, then connect to it via CLI. We go into 'tests' and run 'altitude'.
We get back
BARO: XXX
The XXX will vary from -55cm to +20cm just sitting still. If we then drive around and go over sevarl altitude changes we'll see the altitude tack our changes but still have a ~150 cm swing that is pretty random.
We do the same car driving test only output the GPS and get very steady results. I would like to uset he GPS as a 'low pass filter' for the barometer, or to be honest remove the barometer outright.
In the 'old' ardupilot code I remember a variable that would enable or disable GPS mixing. I can't find this in Arducopter though. Is this still an option? If not, does anyone have any suggestions on what to do? I was thinking of implementing an alpha filter on baromter but it will take me a while to find the best place in the code.
Thanks,
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