MacDon Swather, Differential Steering

I have put AgOpen system into our MacDon swather. Has done a fair bit of work now and we are impressed with the performance of the system so far.

The system has DC gear motor on steering wheel, WAS sensor on drive pumps, Single antenna with SparkFun ZED-FP9 with RTCM3 via serial, BNO085 for heading + roll correction.

The BNO085 is working perfect, it transformed the whole system. Without the BNO085 it could hold the AB line OK but never drive onto the line, With the BNO085 it can drive onto the AB line from a 45deg angle with no problem at all.

When the sun is not so bright i will get a video of it working, then ill workout how to post it here. For now here is a quick preview of the steering motor tho.
Macdon AgOpen


Can you show detail of your WAS setup and any specific code you used?
This is really interesting! Thanks for sharing

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Great work! I’d like to see Was pictures too. Are you using uturns?

Are you using stanley steering or pure pursuit in AOG?

I have just made some arms down off the drive pumps for WAS as picture below, the code is just the BNO085.ino Math shared on the page about that subject.

It will almost do a wide uturn, but my motor is not quick enough to turn out of it. We just have a pedal on the floor, at the end just press pedal to lift motor off, manually swing around (Motor just goes crazy for a second) release the pedal it sorts itself out straight away and your off again down the next run.

We are using pure pursuit, it seems much more stragiht foward to setup in my brain?

To get the correct wheel angle to start with, just connected a bar in center of drive wheels and drove at avergae operating speed in a circle towing the bar. Turned the machine off then measure the angle with tape measure.

Macdon WAS
WAS Measuring


Looks good. I put aog on a swather like that a couple years ago and it was sort of ok but needed better heading. I’m glad to hear that bn0085 helped as I’m sure that’s what mine was lacking.

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You have any more photos of the motor mount?

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