GPS Follow the line AB Curve

Hello everyone,

My Set up is with an dual Antenna System and the esp32 and Code from MTZ8302.
My question is now what are your expierence with follow the line in AB curves.
On an nearly straight line I am really sattisfied with the Performance. But when it comes to some smaller AB curves like an 30° Curve the tractor is always to much off the line with 7kmh. The tractor always drives an biger radius. But in the steering chart there is no big errors when driving the AB Curve. So the Motor can follow the green chart. So my question is where is the Mistake? Is it maybe the Look ahead factors? What are you expierence at AB curves?
Regards, Peter

I think for your application you should try “contour mode”. The contour mode changes radius on consecutive passes. The AB curve keeps the exact same pass just moves it over if I error not.

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Okay you mean the Button where it follow the contour of the field? But i guess its just for the outer Pass around the field?
I made an Ab line on a Road with some curves. That Was my AB line. At straight ahead Part it works. But for curves it does not follow ecaxt.
Regards Peter

Sounds like your steering angle in AOG does not match real world. Recheck all settings for tractor.

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this is the nature of an AB curve it is taking the exact line and off setting it. So it will get tighter and narrower. See attached.

I will play with contour. You an use in the field but I dnt know if the auto uturn will work like an AB line.

Note: I only found this software a week ago so dnt know all the ins and outs.

@Bada Pure Pursuit or Stanley?
I use AOG 4.3.10 single antenna, RTK, right now BNO correction disabled only fix to fix 1m.
I had the same problem. When I was set in Pure Pursuit and AOG set to follow an AB line quite well it wasn’t able to follow the line in tighter curves (in AB cures and Contour Lines, doesn’t matter) sometime as far as 70 cm off. In stanley mode it’s much better.
I played a lot with counts per degree, look ahead, BNO on, off, more or less and other parameters but was never able to make it follow a curve and drive a strait line within a few centimetres with PurePursuit.

How you measure your maximum degree of the Wheel in the best way? Make sense that the Real angle of the wheel and the measured one is not the same. Would Clearif why the Red and green line looks good. But in Real life it does not reach the curve exact. I will check that
Regards Peter

@Pat i will try Stanley and counts per degree.
How you Set up Stanley? Just play with the two adjustments and try whats best. Or is ther Kind of an recept
Regards Peter

This video (found under play button at top of this page) should give a hint.

My tractor can do about 37 degree to each side 74 degree total. So my max degree is 37

AOG will never demand more than max degree, and if I set max at 25 degree(as seen in green set point), AOG will not turn tractor wheels fully (Assuming your red Actual degree is showing correct)

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Here i have a Question when you talk about 37 degree which angle is it? Is it the soo to say middle wheel angle or the angle of the inner Wheel?
I have my wheel Sensor on the right side. So when i adjust the counts per degree schould i adjust it to the inner angle 47.4 degree or to the middle one? 35.7 degree. I guess AOG always calculates for the virtuell wheel between both?
So it would Show then 35.7 degree on each side with Ackermann adjustments.
Regards Peter

I did it the simple way,because my sensor is on the middle of the connection rod between wheels, and then no Ackermann.
I just measured the angle from centerline to one wheel in inner circle position, the other wheel would be the same.
I agree the measured wheel does have less angle the other way.
But remember Ackermann can be accounted for in the settings in AOG, so shown angle to both sides (on screen) can be the same.
I would start with the middle measurement, and adjust Ackermann % till it show the same at both sides.
Then find what angle max can be (so motor stops just before steering wheel hit end.)
Later you can do the same thing with the other angles, and test what you prefer.
Tractor will steer fine on AB line in all 3 scenarios.
U-turn and contour can be different.