Hi Ewoud, Felix,
Yes, I took the previous current calibration completely out of the airframe file for the last test, to see the effect most clearly. It did drift a lot (around 80°!).
The "real" direction in the screenshot above is around -60° the whole time. But as the copter keeps turning clockwise, I had to yaw left (the down steps of the green line).
While replaying the flight, the GCS shows the copter pointing almost south while in reality it was still pointing roughly 300°. See the two walking paths marked in yellow and red and compare it with the video.
As the next step I will do another current calibration and compare it with my earlier values. Though, my question is: Without any current calibration (like in the test above), do you get to see an psi offset of as much as 80-90°? This sounds a bit too much. Will a better current calibration help here or am I better off rewiring the power cables all-together?
The full video: https://youtu.be/F1WrH9zZjNs
In the video I am engaging hover mode three times. The last one @1:57 is quite dramatic.
Simon
Am 23.07.2015 um 18:33 schrieb Ewoud Smeur:
Yes, I took the previous current calibration completely out of the airframe file for the last test, to see the effect most clearly. It did drift a lot (around 80°!).
The "real" direction in the screenshot above is around -60° the whole time. But as the copter keeps turning clockwise, I had to yaw left (the down steps of the green line).
While replaying the flight, the GCS shows the copter pointing almost south while in reality it was still pointing roughly 300°. See the two walking paths marked in yellow and red and compare it with the video.
As the next step I will do another current calibration and compare it with my earlier values. Though, my question is: Without any current calibration (like in the test above), do you get to see an psi offset of as much as 80-90°? This sounds a bit too much. Will a better current calibration help here or am I better off rewiring the power cables all-together?
The full video: https://youtu.be/F1WrH9zZjNs
In the video I am engaging hover mode three times. The last one @1:57 is quite dramatic.
Simon
Am 23.07.2015 um 18:33 schrieb Ewoud Smeur:
Hi Simon,
Maybe your magnetometer picks up the magnetic field induced by the current through the wires. You can calibrate for that:
http://wiki.paparazziuav.org/wiki/ImuCalibration
See the section 'Calibrating for current'
Ewoud
Date: Thu, 23 Jul 2015 15:54:22 +0200
From: address@hidden
To: address@hidden
Subject: Re: [Paparazzi-devel] Copter isn't holding its position in hover (H_ZH) mode - with video!
Hi Felix,
I did another test earlier today. This time with more extensive logging and again with video. The psi value seems to be off to the left (ccw) during flight (not on the ground, though). But I am still evaluating the data and comparing it with the video. Another post on Youtube is to come once I am done synchronizing the screen cast of the replay with the on-board recording from the GoPro.
Sim
Am 23.07.2015 um 15:09 schrieb Felix Ruess:
Cheers, FelixDid you also test if the heading (psi value) stays the same/correct if you start rolling/pitching the quad?Hi Simon,any updates here?
On Fri, Jul 17, 2015 at 9:41 PM, Simon Liebold <address@hidden> wrote:
Hi Gautier,
A wrong heading estimate would explain it. But during a bench test right now the pointer on the GCS (and the value of int32 psi) agree with the heading of my phone's magnetometer.
In the next few days I will test if the psi value changes when I ramp up the throttle. I did a current calibration. But maybe not correctly.
I will keep you posted.
Simon
Am 17.07.2015 um 19:13 schrieb Gautier Hattenberger:
Hi Simon,
I looked at your log and video, and it seems that the problem is coming from the magnetometer resulting of a wrong estimated heading. According to your position error, the applied command on roll and pitch is correct (and matching the video) but it ends up going in the wrong direction, as if the frame is pointing west while the estimator says it is pointing east.
Could you check on the GCS screen that your frame is pointing in the correct direction: turn the frame in your hand and check that it is matching on the map. Maybe you can try to recalibrate your mag if it seems to be the problem.
http://wiki.paparazziuav.org/wiki/ImuCalibration#Calibrating_the_Magnetometer
Gautier
Le 16/07/2015 18:23, Simon Liebold a écrit :
Hi Gautier,
I just uploaded it to here: http://sl.formfall.de/paparazzi/15_07_15__11_48_08.tar.gz
Simon
Am 16.07.2015 um 15:57 schrieb Gautier Hattenberger:
Hello,
Can you also post somewhere the full log files (.log and .data files) ? Your airframe seems at least correct.
Gautier
Le 16/07/2015 15:35, Simon Liebold a écrit :
Hi all,
I am trying to understand why my copter isn't holding its position when I switch into hover mode. It does update the x & y set points but it still goes and flies off (not just downwind but in a random direction). Yesterday I was able to catch it on camera.
https://youtu.be/4Cp9Vrx_9-4
Please disregard the crash at the end of the footage. My real question is: Why does the horizontal loop not work correctly - or even work at all? Maybe somebody can give me some insight.
http://pastebin.com/jQH5AkrhSimon
$ ./paparazzi_version
v5.5_devel-1378-g0c8fd3e-dirty
p.s. The copter suffered some damage on one of the props, but nothing serious.
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