Fine Tuning for IH 5088 with Baraki OC Hydraulic Valve - Get the Jitters Out

I’m experiencing some occasional “jitter” in following lines in autosteer. My first thought was to turn down the gain, that didn’t really have a positive effect. Turning down the max limit helped noticeably, but I still experience occasional jitter, as if sometimes the system gets into a positive feedback loop.

I haven’t gotten into the Stanley or Pure Pursuit settings yet. I don’t really understand how those might affect performance, so I wanted to ask before blindly changing those settings.

My specific application is with an IH 5088, OC valve, 30L flow rating. I looked up the steering cylinder specs. Looks like it’s a 2-3/8" bore x 1" rod x 8" stroke (60 x 25 x 200 mm for metric fans).

I’ve seen a couple of threads about fine tuning steering parameters, but I wanted to break out a new thread for discussion on tuning for the Baraki valve.

You can largely follow the same tuning process, no matter what’s steering it, so any of the guides you’ve seen should apply in principle.

CPD (WAS count per degree) and valve MIN are the critical values to have good performance of the system

Calibrating an hydraulic valve (similar applies to a steering motor):

First the hydraulic oil/whole tractor should be at working temperature, if the valve is calibrated with cold solenoids minimum value could be to small once warm.

I would recommend to use the steer wizard first, it gives you the steps in the good order, to understand the mechanics.
Should give good results, maybe make it more than once.

To calibrate manually the order is:

  • enter all the vehicle dimensions
  • calibrate the WAS, ensure that CPD is set so that around 5 degree the circle record value matches the actual value
  • The first step for valve/motor calibration: the min value, go in “drive” mode, set P to 1, “min” to 1, drive slowly. Give a couple degree of error then increase min until the wheel move nicely but slowly.
  • then calibrate P and Max. use the “center/5 deg” button to give 5 degree errors, increase P and Max to have the wheels moving as fast as possible without overshooting.

P 15
max 80
minimum 35

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Thanks all. I’ve got things in pretty good shape now. The jitters are all gone. I spent the day yesterday pulling a lime trailer, and it was great to navigate headland turns and really give the system a real workout!

I think the last thing left to fine tune is the Stanley/Pure Pursuit settings. I seemed to have a bit of oscillation in holding a straight line.

Other than that, I’m thrilled to have the system functioning well.