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GPS antenna mounting on tractor


(John B) #1

Hi all

I’m working on getting the reach set up for lightbar type of guidance on my tractors this spring. I’d like to be able to move it between different tractors easily.

With the stick on antenna, what are the best ways to create a moveable mount. Should I put the antenna on a 100mm metal disc and then create a mounting point on that for the different tractors? Has anybody rigged up something simple that I can copy?

Last question, I will be running rtk. Is the supplied antenna my best option for signal strength(some fields are near tree lines) or should I consider a higher gain, possibly fixed mount antenna?

Thx


(Mr337) #2

Give this a good read!


(Kyler Laird) #3

John, I will just speak from my experience. I am quite willing to believe that there are smarter ways to do what I’m doing.

My bean-drilling tractor was an old MF 2745 with a steel roof. I just slapped little magnetic antennas on the roof and it worked alright.

My next tractor project was an MT765 with a plastic roof. I plan to mount a bunch of other antennas and cameras so I built a big frame for some much better antennas on steel plates. It worked well. https://scontent.xx.fbcdn.net/v/t1.0-9/13606856_10106613732628728_9004130183656332863_n.jpg?oh=957db26703747866d494fc5118e180f9&oe=59427BB8

For a stick-on antenna, I’d definitely use a good steel surface for mounting. The specifics will vary by tractor. Do your tractors have existing mounting points? (My Deere equipment has mounting plates.)

Working near shade, I’d feel a lot more confident going with a bigger antenna. The larger (surveying) antennas often mount on 1" NPT. Mounting one of those is just a matter of securing a regular pipe flange base and screwing in a pipe nipple. Moving the antenna (and nipple) between tractors should be fairly easy.

Good luck!

–kyler

Also, I realize you’re using RTK, but consider putting the antenna as far forward as is reasonable in order to increase accuracy. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3231444/


(Andreas Ortner) #4

I do like this!


(Feepyj) #5

Thanks for the ideas. I’ll be playing around with a mounting bracket before too long… Kyler - the article is very interesting.

A follow-on crazy thought. I’m considering mounting 2 reaches, following a similar approach that you took to allow getting more stable heading and calculating tilt. Need to figure out if I can create the software to read 2 “simultaneously” and compute the info and send the signal on quick enough. Is this crazy? Should I be thinking about another option?


(Mr337) #6

Friend of mine did exactly that but with a different receiver. Also there are dual receiver units that computer location and heading internally. But you’ll need to bring some $$$ lol


(Kyler Laird) #7

I’ve thought about using multiple receivers (because I’d like to integrate them in the antennas and use PoE) but synchronization worries me. Dual RTK receivers (NVS, Tersus, …) are cheap enough that I’m planning on sticking with them for now.


(Feepyj) #8

I have a minimally working setup in place.

A luggage rack cross bar + 2 6" stainless drain clean out covers has worked to test the mount.
I’ve been hacking together a python script that has proving the ability to read both GPS’s and calculate tilt and heading based on the position of each antenna.

Working on then doing the math to generate a single NMEA output sentence for GGA and RMC based on the centerpoint of the two GPS’s and compensated for tilt (assuming some mounting height off the ground). Goal is to sent the sentence to AgOpenGPS open source A-B guidance program.

This seems like a workload that I could probably do right onboard the reach if I understood it better. Right now I’m targeting using a Raspberry Pi.

Ideally, I’d like to use this system as a smart GPS to compensate for tilt and auto switch from both to a single GPS if one looses fix.

It sure would be nice if the IMU on the reach were activated.

If I can figure out GitHub, I’ll try to put up my script and let others play with it (and hopefully improve it)

Raining today - here’s the test setup guiding the couch.


(Kyler Laird) #9

I’m quite pleased with my latest antenna mounts. They’re just beam clamps and bolts. Perhaps the idea will be of use to someone else.