Brian Tee, [07.11.19 01:33]
There are 2 errors for guidance. A heading error and a disctance error. Putting the antenna right over the pivot point really limits the feedback for distance off the line since as the tractor turns, the distance takes a long time to change as the tractor turns toward the line, and will tend to overshoot the line. So it is a balance between moving the antenna farther ahead for distance and the errors associated with heading.
Brian Tee, [07.11.19 01:34]
Some people put antenna over steering wheels, then the distance feedback is very good.
Brian Tee, [07.11.19 01:36]
Stanley guidance uses heading to calculate the distance the steerer wheels are offline, so putting the antenna over the pivot with a stable heading from imu is as good as Pure Pursuit and antenna above the front wheels. It’s a complex interaction
Brian Tee, [07.11.19 01:36]
PP is better for slow slow speed, stanley is better for higher speeds.
Version V4 allows only antenna in front of the pivot axle for a combine. The possible distance antenna to Pivot axle is then limited, is short. So the distance from line feedback would be not good (I had no good experience at the tractor with tha antenna on the roof, but it works well if antenna is on the bonnet). So I would like to place antenna near steering axle. I watched the video “Reverse Guidance or Pivot in Front” with the version 3.x. There it was possible to place the antenna back of the pivot axle. Why has this changed?
I also tried to make the tractor (JD6200 series) drive in reverse. Obviously does not work without changing settings as AOG does not know that the tractor is driving backwards.
I thought I’d configure the vehicle as a combine but that does not work with 4.1.12. I thought someone here mentioned AOG works fine when reversing but I did not find the thread and possible comments on how it was done.
I guess I have to move the antenna backwards, on top of the rear axle or further and try 4.1.12 again with the combine settings?
I guess also, you have to use the combine settings an put the antenna behind the pivot axle. So when driving backwards it is then in front of the pivot axle. Like the picture in the setting for a combine shows. Let us please know, if you was able to make enough distance between antenna and pivot axle.
I tried auto-steer in reverse today. I had the F9P antenna 100 cm from the JD rear axle. Inverted WAS, steer direction and roll because left and right get swapped when you drive backwards. AOG was doing pretty well. I did not touch autosteer settings from the values I had for forward driving.
I left the ackerman correction untouched, not sure if it should have been “swapped” too. Got head ache when thinking about it. Should have had a look at the steer window but since I was not U-turning, AOG probably works fine either way.
That’s good to hear. I was a little bit afraid, that 100 cm is a too small distance for antenna placement. So I have to rethink my decision regarding the combine with AOG.
The ackermann settings can easily checked. Open the autosteer settingswindow an turn the steering wheel totally left/right. If the shown wheel angle is both the same, then ackermann settings are okay. You agree? And I think, inverting tha WAS shouldn’t affect ackerman.
Hola, cual es el lugar adecuado para colocar la antena en un tractor? Sobre la parte delantera de la cabina? Sobre la parte trasera? Sobre el motor? o delante del eje delantero sobre un pequeño mástil?
Bonjour je suis nouveau ici, cela fait un bon moment que je cherche sur ce site, à aucun moment je n’ ai vu abordé le sujet de la correction de devers, question primordiale avant toute essai de vers une précision centimétrique.
Most of the discussion here lately is about this very topic. People are discussing using an IMU to get accurate roll and heading information. The IMU that is being focused on right now is the CMPS14 unit, from RobotShop.
AOG has been able to compensate for machine roll for a long time now. The problem was finding a sensor that wasn’t too noisy, but was still affordable. The CMPS14 seems to do that nicely, and can help determine the heading. Also the BNO085 is still being looked at and may be able to do everything the CMPS14 can do.