tractor guidance

Posted by Andy Dombeck on February 28, 2014 at 6:02pm

 i have a project in mind involving my tractor and my farming operation. what i want to do is use gps to steer the tractor for me (that i will be riding in at all times!) so i can focus on other tasks while doing tillage and planting.  it will only have to drive in a straight line i will make the turns and line up for the next pass.  my thoughts were have a pixhawk and piksi along with a stepper motor assm to manually turn the steering wheel. two methods i was thinking of were trimble ez steer or agleader.  we have used a light bar guidance on our farm before but this year going to conservation tillage and need to drive over the previously placed fertilizer strip with the planter within 4" or better. with our small farm we can not justify the large expense of RTK.

what is everyone response or concerns to this idea?  i appreciate any input or suggestion i can overlook some important details at times

thanks

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Replies

  • Richard Way August 1, 2016 at 2:38am

    Thanks Kyler

    I have started  to order some of the bits  required , next step will be having a go some coding  .

    Richard

  • Kyler Laird July 25, 2016 at 5:31am

    Here is the clutch (before I trimmed the bar):

    18021_10105231976069948_1653601430829547213_n.jpg?oh=d8c3ae85765e5c83c37572065e2f9a51&oe=58309FF3

    This is the steer angle sensor:

    11701063_10105267465099648_8205234603085526908_n.jpg?oh=ef5b4b48b3e3d234b3b29e2df1d2e02e&oe=5836C4D3

    I use an NVS-NV08C-RTK-A dual RTK GPS.  The Tersus Precis-BX316 looks like it will provide similar functionality and adds L2 reception.  I'll take a look at it when it's released but the NVS is a good fit for me - sufficient accuracy and USB interfaces.

    --kyler



    Richard Way said:

    Thanks for your reply Kyler

    Is cold wet and windy today in SA , a good day to be inside ....

    Can see the steering controller but not the clutch .. i have a bigger screen look  later.

    The python GPS script  works well  , what are using as your GPS ?

    Richard

  • Gary McCray July 24, 2016 at 8:46pm

    Hi Andy,

    Talk about timely, Tersus just put in a Blog for their new RTK system $2000.00 for a full package ready to go.

    Which looks like it would be excellent for your application.

    http://diydrones.com/profiles/blogs/precis-bx305-quick-start-guide-...

    http://www.tersus-gnss.com/collections/all

    Best Regards,

    Gary

  • Richard Way July 24, 2016 at 7:48pm

    Thanks for your reply Kyler

    Is cold wet and windy today in SA , a good day to be inside ....

    Can see the steering controller but not the clutch .. i have a bigger screen look  later.

    The python GPS script  works well  , what are using as your GPS ?

    Richard



    Kyler Laird said:

    Hi, Richard.  I can certainly give you some info about the MF2745.  I am delighted with how well I was able to make it work but it needs to be much more accurate for planting corn.  I have an electronic flow control valve that I want to incorporate to see if I can make finer steering adjustments.  I think it will make a big difference.

    Speaking of a big difference...I've been meaning to post about my latest project, Tractobot02, a Cat/Challenger MT765.  It's amazing.  I can control it using two PWM signals - easy and accurate.  Here is my initial navigation testing yesterday:

    https://www.youtube.com/watch?v=8IjQt9OyjWQ

    It is so much easier to get great results with the Cat.  I tuned the steering PID a bit today (and added a gain scheduler) and it was able to keep within a couple inches of the line up to 20 MPH.  (I was hanging on for dear life at that point but the navigation was solid.)  Note that this is still with my really dumb GPS-only Python script (now running under ROS.)

    I enjoyed making the MF2745 useful but working on the Cat is a vastly different experience.  Instead of tweaking hardware, I get to concentrate on software.  I am now confident that I have no need for APM.  ROS is a vastly better infrastructure for what I want to do.  I've been thinking that I will want to incorporate IMU code from APM but after today's runs it's hard for me to justify putting much effort into improving the navigation.

    You can see the steering valve and clutch actuator in this video.

    https://www.youtube.com/watch?v=CHHJ2gaOzgM

    I'd be happy to make another video with more detail.  I'll try to answer any questions you have about what I did.

  • Gary McCray July 24, 2016 at 7:14pm

    Hi Andy,

    A few of our DIYDrones members have already done this with some remarkable successes.

    Matt Reimer in particular has a system fully operational and in use.

    You might want to contact Matt Reimer directly.

    Here are some links to his development.

    http://diydrones.com/profiles/blogs/pixhawk-powered-tractor-on-hack...

    http://diydrones.com/group/ardurover-user-group/forum/topics/apm-ro...

    DIYD member Grant Morphett is also heavily involved in this.

    That said, GPS, even GPS / Glonas will not get you within 4 inches on it's own, you really need RTK for that or some other means.

    That said, there are now a number of RTK products that plug directly into the Pixhawk without breaking the bank.

    If you Search DIYD for "RTK" I am sure you will find some.

    An alternative might be to use a laser and retro reflector, but the software would need to be home brew and would in my opinion be a substantial development effort.

    RTK for Pixhawk is probably your best bet and the interface should be easy if not already done to your satisfaction.

    Maybe others will disagree with this conclusion, but it is just my thought on the matter.

    Best Regards,

    Gary

  • Kyler Laird July 24, 2016 at 6:43pm

    Hi, Richard.  I can certainly give you some info about the MF2745.  I am delighted with how well I was able to make it work but it needs to be much more accurate for planting corn.  I have an electronic flow control valve that I want to incorporate to see if I can make finer steering adjustments.  I think it will make a big difference.

    Speaking of a big difference...I've been meaning to post about my latest project, Tractobot02, a Cat/Challenger MT765.  It's amazing.  I can control it using two PWM signals - easy and accurate.  Here is my initial navigation testing yesterday:

    https://www.youtube.com/watch?v=8IjQt9OyjWQ

    It is so much easier to get great results with the Cat.  I tuned the steering PID a bit today (and added a gain scheduler) and it was able to keep within a couple inches of the line up to 20 MPH.  (I was hanging on for dear life at that point but the navigation was solid.)  Note that this is still with my really dumb GPS-only Python script (now running under ROS.)

    I enjoyed making the MF2745 useful but working on the Cat is a vastly different experience.  Instead of tweaking hardware, I get to concentrate on software.  I am now confident that I have no need for APM.  ROS is a vastly better infrastructure for what I want to do.  I've been thinking that I will want to incorporate IMU code from APM but after today's runs it's hard for me to justify putting much effort into improving the navigation.

    You can see the steering valve and clutch actuator in this video.

    https://www.youtube.com/watch?v=CHHJ2gaOzgM

    I'd be happy to make another video with more detail.  I'll try to answer any questions you have about what I did.

  • Richard Way July 24, 2016 at 4:42pm

    Hi Kyler

    I like to know more about your system , Am thinking of doing what you have done , I even have the same model massey as test bed tractor

    richard



    Kyler Laird said:

    I started trying to use APM but the more I got into it, the more hassle it seemed.  I built a system from scratch.  I use a dual-RTK GPS and a Pi3 (running a Python script).  I get remarkably good performance for it being such a dumb system.

    https://www.youtube.com/watch?v=LhKV-5O64IY

  • Kyler Laird June 25, 2016 at 6:34am

    I started trying to use APM but the more I got into it, the more hassle it seemed.  I built a system from scratch.  I use a dual-RTK GPS and a Pi3 (running a Python script).  I get remarkably good performance for it being such a dumb system.

    https://www.youtube.com/watch?v=LhKV-5O64IY

  • Daniel Hanson March 22, 2015 at 2:25pm

     Andy,

    This will be my 3rd year using a FM750 with EZ- pilot using RTX (as I understand it, using Russian satellites for correction). purchased from a local Case IH dealer. mounted in a JD 8200. accuracy of just over 1 inch, repeatable. there is a yearly subscription fee, around $1500usd.

     I have been very happy with this system. total cost was around $6000-$7000. at the time this system priced out many thousands less than a RTK system.

     I see you live fairly close. I'm north of Rochester.

  • tommy March 22, 2015 at 5:04am

    Love this idea, I was thinking something similar but in the future for me as I am still learning, I am currently trying to complete my first build using the APM 2.6 if it works well I will hopefully trasnfer what I know to the tractor. do you have any progress reports?

This reply was deleted.