Hydraulic steering wheels oscillate rapidly

Hardware Autosteer
1

I am trying to help out a friend of mine. I have built a couple of systems that have both performed well. My friend decided he wanted to give AgopenGps a try. I helped him get started this winter. He installed a hydraulic steering valve, a v4.5 std AIO board with zed-f9p and he is using the Delphi ride height sensor for a wheel angle sensor.

I helped him though a couple small issues IMU and WAS, but those both seem good now. His tractor would rapidly oscillate the wheels back and forth probably 20 degrees in each direction. He originally ordered a 5 GPM Hydraforce valve (sp10-47c) that valve was changed out for a smaller 3 GPM valve (sp08-47c) but the wheels still rapidly oscillate.

His look ahead settings and steering settings all look pretty normal. Even when turning down the min and max pwm settings fairly low the steering still seems way to quick and the rapid oscillation still occurs.

Does anyone have any good ideas as to what may be causing this? I am running out of ideas. Thanks (tractor is a John Deere 4230)

2

First the Proportional should be pretty low for hydraulic valve, around 10. (4 to 20 typically)

Secondly, how did he connected these 4 way hydraforce valves? Does he have installed some kind of compensator? Because there is none in these valve.

3

Thanks for the suggestions. He does not have a compensator. That was brought up as an idea as well.

4

I’m having the same problem (JD4960). Did you ever fix the problem?

5

We never got his tractor completely ironed out. We kept lowering the PWM min and max and eventually got it responding reasonably well. The steering is smooth one way, but seems to catch and suddenly pop the wheel over the other way. In the next week or two the plan is to get his tractor in the shop and rebuild the front steering motor and install a steering valve update kit under the dash, then give the autosteer another try after the manual steering is gone through.

6

I see, keep me posted if you want. I hope to work on ours in about 4 weeks. I was going to try to look play with the flow by adding a manual flow control for testing purposes. With a low maximum pwm it was reasonably straight, the nose keeps wondering around 8-10 inches. High high rpm starts oscillating.

I am afraid the flow adjusting will not help, the pwm should already take control over the flow control, but I ran out of things to try last year

7

After some testing, I changed the BNO085 with a TM171 IMU. It looks like this helped a bit with stability. Having the PWM min set at 28 or 29, and PWM max just under 60 makes the tractor work somewhat decent. I am still trying to finetune it, but it can stay within the couple inches, using a base 30miles away. I would like to try a flow reducer at some point, or replace the original 30L? cartridge for 15 or so, so the PWM can be much higher, and gives more room to work with before it gets into oscilation.

8

Where is your gain set to? I’m dealing with a 818 fendt that oscillates really easily and I figured out there’s a big difference how much weight there is on the front as to how quick it starts oscillating. With a loader on , with min at 41 , gain at 39 it operates really nicely. Take loader off and add some draw bar weight, I have to turn gain back to 20 to get it to work.

9

But it will hold the line at 1 inch so not sure it’s same problem

10

I had my gain set at only 2. If I would set it to three or higher, it starts to oscillate. I think the block is not going to work how it is setup now, because it’s between the steering motor and a metering valve under the hood, which runs a internal valve to control the high flow to the steering cylinder.

I might try to replumb the system, and put the block right in-between the metering valve and the steering cylinder, I just don’t know what for affect that will have on the extra lines that run back to the metering valve, coming from the rack&pinion