Bang bang valve stays on to long

Can someone point me in the direction of where in the AOG code the duration of the pwm is set. I have played with the settings a fair bit but it seems that the duration of the signal sent to the board is to long and the tires either oscillate to much or respond to slow, I do not seem to be able to get the motor controller to come on for just a split second to correct the heading a minimal amount, and if I slow things down it does not turn fast enough for the uturn. The valve is just an on off valve, and I have tried playing with the minimum PWM, and the valve does start to turn the wheels around 60 to 70 on the pwm setting, but try as I might I cannot get it to be stable. I have tried the most current beta, and now the new release as of yesterday, but the same problem continues. I have enabled and disabled my brick controller and the roll on the autosteer board to see if that would help but same problem, At the end of the day if I manually click the button on the motor board I can move the wheels just a tiny bit, but I cannot get AOG to do the same tiny movement with the valve and I should be able to move it an even smaller amount given digital switching versus the speed of my finger on a controller.

I saw a post a week or so back with someone else using an on off valve with similar problems and I think they adjusted some code and had to use a previous version, but try as I might I cannot seem to find it today, can someone point me in the right direction, on the code or the post or both.

The on / off valve is absolutely not suitable for automatic steering! You must have a proportional valve and this is not the first but better quality, and I also recommend a pressure compensator.

As baraki says it will not be really good. But cheap way to improve is reducing flow by a needle valve or even a ball valve

One would think, if you can do small adjustments by hand, than the Nano should be able to do that likewise or better. The problem is that the current nano code is proportional valve/PWM oriented. And an on/off valve is generally not at its best when “half-open”. In your setup, the Arduino code should be able to vary the duration of a steering action. This nis nothing new, I found this:

An underused control strategy that offers significant benefits is Time-Proportional Control (TPC). Unlike traditional proportional or even PID control that require a varying output to a modulating control device, time-proportional control can achieve a proportional control response to process variation using an on/off device by varying on and off times in a defined control period. The on/off device is generally a simpler, less expensive control device.

I wonder if this could work for on/off valves. It would require the Arduino to code to limit steering action in time.

I have a home built bale wrapper, that I do on/off pulse for last 1/4 turn before film gets cut… Problem is, when it’s first started from cold it will completely over run as though it was just on… 10 bales in it will work perfectly…… 400 in on a hot day it doesn’t have the power in the on time to move much!
Think it’s to do with oil temperature.
Timings would need to be on what its doing…not on what it should do!

I also made such a wrapper. I solved braking and starting in such a way that during the first and last 1/2 turn an additional solenoid valve on / off switches the regulated throttle valve into the system. Works quite well.

Mine has 2 speed fixed restrictor valve also…
Keep saying I will rewrite code for an Arduino as currently running on a pic chip.
Its 19 years old !

I use the PLC + HDMI panel to control because I do not understand the arduino code.

We were able to get this working with modifications to the code, it works very well with the bang bang valve, I agree a propotional valve would be better, but the tractor already had this on it, and it appears to work better than the ezsteer motor we had on it before, so quite happy.

1 Like

What’d you have to do?

modified arduino code such that for any error greater than 5 degrees Brians code is used. For steering error less than 5 degree the code is modified such that the valve is either fully on or fully off, and there is a delay in sending corrections to the valve based on the error to minimize the back and forth than occurs with the high frequency of outputs provided with brians code.

Mind posting it up and a screenshot of your settings? I ripped the WAS off my combine one of the times it sunk this spring but I know it wasn’t working quite right after upgrading to v4

1 Like

when we get done seeding and have sometime I can try to put something up, right now the code is a mess it was changed in the tractor, and some of the items were hard coded, and other slider functions changed, but no names or changes were put in the code it was just to get the unit working for seeding, unfortunately it would not make sense in the current condition to post it, it would just cause more confusion. Hopefully once seeding is done will have some time to clean it up and will post at that point.