An Update, a poster on the Arduopilot forums states that since the airspeed sensor is not reading (for some unknown reason) and that the use airspeed sensor option is enabled, that the autopilot may be trying to dive to recover from the stall. Thoughts?
If you look at the actual log you will see that those popped up right at startup, then cleared. The compass was due to being too close to my car I think, not sure why GPS did that at first, most likely due to trees and my car being to the south of the aircraft.
Mike Mac > Nathan Douglas LindemanAugust 7, 2014 at 9:45am
Have you done a good 3-axis accelerometer cal? That's the one where you have to place the Pixhawk at 6 different attitudes. I always do that before I install the Pixhawk to make sure I get an accurate calibration.
The calibration needs to be done with the latest firmware installed because it uses both sets of accelerometers and older versions did not use or calibrate both sets.
Yes, as a matter of fact, I did this again after the first incident during flight 1, thinking that may have been the issue.I have attached the Tlogs for reference. as stated previously, the plane seems to fly fine and maintain altitude in loiter, but flys well past the assigned altitude, with no visible attempt to pull up in RTL and Auto.
Mike, during flight have at least 8. The GPS error was right at startup, and cleared nearly immediately. Not sure on the compass, however. I don't think the compass should affect pitch control in auto mode.
Mike Mac > Nathan Douglas LindemanAugust 6, 2014 at 4:16pm
My suggestion - first write down the compass cal and re-calibrate it and see if you get about the same offsets.
They fly an Autotune flight or two. I usually fly one and record the numbers then do another to see if they change much.
You need 6 or 7 satellites to get a real good GPS fix. I always make sure that I get at least 6 before takeoff.
After that try something simple like Loiter. It that's ok than RTL then auto.
I have two Pixhawks in airplanes and have never has a problem with auto missions.
Replies
An Update, a poster on the Arduopilot forums states that since the airspeed sensor is not reading (for some unknown reason) and that the use airspeed sensor option is enabled, that the autopilot may be trying to dive to recover from the stall. Thoughts?
Have you done a good 3-axis accelerometer cal? That's the one where you have to place the Pixhawk at 6 different attitudes. I always do that before I install the Pixhawk to make sure I get an accurate calibration.
The calibration needs to be done with the latest firmware installed because it uses both sets of accelerometers and older versions did not use or calibrate both sets.
.
Yes, as a matter of fact, I did this again after the first incident during flight 1, thinking that may have been the issue.I have attached the Tlogs for reference. as stated previously, the plane seems to fly fine and maintain altitude in loiter, but flys well past the assigned altitude, with no visible attempt to pull up in RTL and Auto.
2014-08-03 19-36-06.tlog
2014-08-03 18-58-31.tlog
My suggestion - first write down the compass cal and re-calibrate it and see if you get about the same offsets.
They fly an Autotune flight or two. I usually fly one and record the numbers then do another to see if they change much.
You need 6 or 7 satellites to get a real good GPS fix. I always make sure that I get at least 6 before takeoff.
After that try something simple like Loiter. It that's ok than RTL then auto.
I have two Pixhawks in airplanes and have never has a problem with auto missions.
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If you run the log analysis tool on Droneshare, you can see some of the problems. No GPS, poor compass calibration: