Perfect straight line without MMA, slight oscillation with MMA


I’ve finish at 99% the mounting of AOG on my Fiat F100 tractor. The system work really well on flat land, with only BNO activ (MMA disable): +/-2cm error maximum on a straight line, has you can see on the video bellow:

A picture of a work pass with MMA disable:

But when I activate MMA (with exactly same gain and PP parameter), I have some small oscillation of the driving. Thoses oscillations seams du to oscillations of MMA measurement (something like +/-1,5 to 2°). Has you can see on the video below:

And AOG make some excursions at 5cm to 7cm of the line what never happen with MMA disable.

A picture of a pass with same tool on same field with MMA activ: we can see some oscillations on the pass:

I try to optimise the gain, hight low, high max, min PW drive, also increase loock head distance and time. But I have never succed to eradicate those smalls driving oscillations and beeing as precise as when the MMA is disable. And the excursion of the line was still to 5cm with MMA active.

For soil work, thoses small oscillations are not a big deal (but I would prefer make beautifull straight lines). But as we plan to seed sugar beet with this tractor with AOG, those smalls oscillations are still to hight. I really have to be as efficient as with the MMA disable.

Do you have any idea on what parameter I should act to reduce this phenomenon ?

Thank for your help.


Hi Math,

Have you tried to modify the MMA filtering (in the ino)?

You can try different antenna heights.


I haven’t try: I was hoping that some trick on the directions parameters could improved the situation. But I think you are right, the only way to trying to solve the issue is the filter. But I haven’t any knowledges on the Kalman filter so I have to learn about before trying to modified the parameters. Or first trying to make the slope filter before the Kalman more restrictiv.

But at the first step I will try to improse the fixing of my box and adding foam or bumper below to see if that can filter some frequency.

I don’t think: if the antenna height in AOG doesn’t correspond to the real antenna height, the tilt correction is going to be wrong.


Did you solve your Problem?


Yes, by switching on BNO08x.


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