Difficulties in installing AGOPEN (solenoid valves) on the Russian Kirovets articulated tractor. It oscillates

I set about installing AGOPEN on an articulated tractor. I already have a lot of experience using hydraulic valves so I thought it was going smoothly. I was wrong!
The steering system on this tractor consists of an orbitrol which steers the pistons via a Danfoss amplifier.
When I connect the proportional valve between the orbitrol and the amplifier so that the proportional controls the amplifier, the tractor already oscillates quite significantly when stopped (even at very low PWM settings.
If I connect the valve directly to the piston, the flow is too low and the control will not follow what AGO wants, and it still oscillates right-left when stopped.

I don’t know that Danfoss valve, but did you block it totally in your second test (6/2 valve or disconnected Danfoss valve?)
If disconnected and still oscillating when autosteer is active, it must be electrical issue. Check steer chart and was signal.

This is such a valve:

Electrically ok. I installed the steering sensor carefully, the steering wheel gives exact and stable values when turning.
the plot at a standstill gives sharp peaks left and right. When the proportional throttles to 0, I have the impression that the OSQA valve does not hold its position but releases the actuator.

Did I understand correctly that it oscillates even without the flow amp? Play in the steering cylinders?

Please explain what kind of plot and from which component? Pressure, Volt or Ampere ?

I meant the AOG targeting chart
I didn’t make a screenshot, but it looked more like in the attached drawing and it happened at a standstill.
I don’t know how to experiment further.

Where is your GPS antenna mounted? Does it move sideways when steering at standstill?

Almost looks like your tractor is rotating on the AOG screen. :slight_smile:

So I don´t think problem is hydraulic !

Did you set coordinates to your place (sim coords /field coords)

Do not use roll until you have found the fault. Or perhaps Zero the roll!

I have the antenna on the front edge of the roof, 1 meter back from the front axle.
This is not a problem with the GPS or the skate. I’m not a beginner AGOPEN fan, so I already get it.
This oscillation already occurs in the manual control mode with arrows. While driving, this oscillation is not visible, at least in the configuration in which I tested in the field, i.e. direct supply of the pistons from the proportional valve, but then the control was too slow and it was not possible to keep it on the line. When I had it connected through an amplifier with an orbitrol cut off by a 6-way valve, the steering was fast, but the oscillations at a standstill were so large that I thought it was pointless to test in the field (although now I think that maybe while driving, they would not be so terrible.)
It is so that in the manual control mode, when the value requested by AOG, e.g. 0, is equal to the steering angle sensor indication, i.e. also 0, the swinging starts from right to left, as if the system could not achieve balance for some reason …

I know you are not a beginner, but I still believe that you have some electronic problem.
Do you use same PCB and computer for this setup, that you have used before?
Edit: You can make a quick test! Disconnect wires to the proportional valve, and with autosteer ON. If still oscillating when at stand still, then it must be hydraulic issue. And if no movement after connectors are taken off, then problem must come from PCB or AOG

Hello. It seems to me that the whole problem is in the bundle - the proportional valve and the amplifier. They have different response pressures and the principle of communication. A colleague of canadaboy25 made a wonderful addition to the AGOPENGPS program, adding the principle of temporary valve control. I think you should look into this.

All electronics are the same as used in other configurations. Mr. computer. CFD1. The next day after I was struggling with this Kirovc I installed an identical kit on the fendt 820 and everything works as it should!
When I turn off the autoster button, it stops oscillating …
I think it has to be related to a delay in the response, there is some kind of interference.
In 2 days I will make more attempts to tame this Russian beast’s 500 horses

You are probably right that the ON / OFF valve version could work because the problem is probably in the response time of the hydraulic system that does not keep up with AGOPEN

I suppose your steer chart have an almost straight red line of actual degree when you turn off autosteer.
Perhaps change position of gps antenna.
I have this thinking, AOG see that antenna is a little to the right, want to steer left, but that action moves the antenna even more to the right. Now WAS signal tells it is too much, and steering must go the opposite way.
I suggest to try antenna right over center of front axle.

Okay, I’ll test the position over the axle.
The problem with the oscillation was in the arrow control mode where, in principle, AGOPEN only aims to set the manually set steering angle. The wheels turned, smoothly reached the given angle, and then instead of stopping, they oscillated.

Well then my bet will be on the WAS signal.
Edit: came to think of the min PWM, does it oscillate in arrow control mode, if Min PWM is set low or at zero?

On our sprayer I have the GPS antenna slightly ahead of the front axle and when steering back and forth while parked, the antenna moves in the opposite direction. I’ve seen other tractors do that too.

I think that the problem is in the steering system of the tractor. For Kirovets usually proportional valve with flow 140 l/min used and connect directly to the piston. QSQB will not allow to work auto steer correctly. Anyway, what are your results?

So I have an idea to solve the problem. I want to use a block with 2 proportional valve sections, thanks to which I can get a large flow from smaller valves. However, control of these valves remains to be solved, the easiest way is to connect them in parallel, but the better effect would be if only one valve could be controlled with a small error, even it could be with a lower flow and connect 2 as the error increases. I was browsing the INO code and I have no idea how to do it. From the electrical side I was thinking to use an additional citron, I am also thinking of a separate nano that would process PWM from the main nano reducing the fill by a certain amount. I am counting on a hint in which direction to go.

I think the same Nano could still easily output another pwm if the steer angle error was greater than a certain amount. It will be more programming work to add the supporting code to configure that second pwm’s parameters like we do the first.

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