Hi all,
I am Daniel, a new pypilot user located in Portugal. I use a very recent pypilot computer to control an old ST4000 tiller actuator with rudder sensor feedback.
I followed the instructions to calibrate the IMU. Accelerators calibration at home, then locked the accel. calibration. Then, after installing the pypilot in the boat, setting the alignment. Finally, the compass calibration setting began with first circling and maneuvering in calm waters. I left the compass calibration unlocked, as it is assumed that it should update continuously while sailing.
Then I did some hours sailing with few wind and waves to discover the behavior of the pilot, and set the pilot gains. No noticeable problems during these first sessions.
A first problem occurred last week after several hours of sailing with more swell. While we were coming back with down wind and waves, the compass became crazy, with erratic readings and and “compass distortions” messages. Even in gps mode the pilot was unstable. We finished using manual control, and the compass calm down while maneuvering in the marina.
The same problem occurred again yesterday after one hour shaking facing the swell. Erratic readings of the compass, and even instabilities in gps mode. Assuming that it might use corrupted data from the IMU I nullified the DD gain and it worked better.
Finally, making a slow circle under engine allowed to get a “calibration same as old one” message from the compass. I then locked the compass calibration, and could sail quietly several hours under pilot control, under compass or gps modes, with no other problems.
However, the calibration screen displayed again some alert messages, “need more range” for the accelerometers (although its calibration was still locked) and “insufficient coverage” and “sigmapoints flat, 2D fit only...”for the compass (see files).
When restarting this morning in the marina, no such messages were displayed… (see pictures).
Is this behavior known? Do I need to lock the compass calibration as soon as the sea is not flat? How can I know that the compass calibration is sufficiently accurate?
On the calibration screen, there is a yellow spot at the top of the sphere, both for accel. and compass: what does it means? Do I need to recalibrate the accelerators?
Thanks,
Daniel
I am Daniel, a new pypilot user located in Portugal. I use a very recent pypilot computer to control an old ST4000 tiller actuator with rudder sensor feedback.
I followed the instructions to calibrate the IMU. Accelerators calibration at home, then locked the accel. calibration. Then, after installing the pypilot in the boat, setting the alignment. Finally, the compass calibration setting began with first circling and maneuvering in calm waters. I left the compass calibration unlocked, as it is assumed that it should update continuously while sailing.
Then I did some hours sailing with few wind and waves to discover the behavior of the pilot, and set the pilot gains. No noticeable problems during these first sessions.
A first problem occurred last week after several hours of sailing with more swell. While we were coming back with down wind and waves, the compass became crazy, with erratic readings and and “compass distortions” messages. Even in gps mode the pilot was unstable. We finished using manual control, and the compass calm down while maneuvering in the marina.
The same problem occurred again yesterday after one hour shaking facing the swell. Erratic readings of the compass, and even instabilities in gps mode. Assuming that it might use corrupted data from the IMU I nullified the DD gain and it worked better.
Finally, making a slow circle under engine allowed to get a “calibration same as old one” message from the compass. I then locked the compass calibration, and could sail quietly several hours under pilot control, under compass or gps modes, with no other problems.
However, the calibration screen displayed again some alert messages, “need more range” for the accelerometers (although its calibration was still locked) and “insufficient coverage” and “sigmapoints flat, 2D fit only...”for the compass (see files).
Quote:compass screen:
insufficient coverage: 7 need 14
plane fit found, 2D fit only 3.7165933375099542 [array([ -7.16773151, 237.2477599 , 81.2444359 ]), array([ 0.06108222, -0.99812793, -0.0030984 ])] 0.3998046358258801 1.0725858450956594
sigmapoints flat, 2D fit only 0.03936035019780477 0.25
insufficient coverage: 7 need 14
sigmapoints flat, 2D fit only 0.02245884394495053 0.25
insufficient coverage: 5 need 14
line fit found, insufficient data 0.4 1.1
line fit found, insufficient data 0.5 1.1
line fit found, insufficient data 0.4 1.1
Quote:accelerators screen:
need more range 0.0004
need more range 0.0004
need more range 0.0006
need more range 0.0007
need more range 0.0006
need more range 0.0006
need more range 0.0007
When restarting this morning in the marina, no such messages were displayed… (see pictures).
Is this behavior known? Do I need to lock the compass calibration as soon as the sea is not flat? How can I know that the compass calibration is sufficiently accurate?
On the calibration screen, there is a yellow spot at the top of the sphere, both for accel. and compass: what does it means? Do I need to recalibrate the accelerators?
Thanks,
Daniel