So between 0-5 deg error, the maxPWM is linearly scaled between lowMax and highMax?
Yes, the steps of PWM increasing with ever degree are same.
It sets the starting PWM and then adjusts the gaps.
Starting with a higher PWM the steps are smaller.
That is what i can see.
My only worry is that i will ruin my low steering values when i have to adjust the high settings for example u-turns
Increasing low max improved my steering. From snake + - 20 cm over 50 m to ± 5 over 10 m.
Admitted it is in single mode (no base) but still pass to pass is ok as I did seeding that way too.
Video show I change low max. The overlap/skips is due to the sidedraft from the 12 m weed harrow 20201001_181144striglevideo.mp4 - Google Drive
Hello,
I made an Excel sheet to Draw the PWM Law of AOG Arduino code function of gain and PWM parameters (Excel sheet base on calcSteeringPID(void) function):
PWM Law.xlsx (47.2 KB)
It’s help me to understant the effect of Low Max PMW parameter on the PWM law. And more generally it’s help me to visualize the current PWM function my paramter and the impact of changing one of them.
And specially for the Low Max PWM parameter: depending on the Gain et High Max PWM, he could have a affect on the law or no effect. I have’nt understand that before.
I validated that the Excel sheet is correct by test on my test bench: it’s ok at +/-1PW (du to rounding). So normaly it’s correct.
Math
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Thank you, The sheet made me understand I MUST get a 12 to 24 V converter (my proportional valve is made for 24 V) My Gain is set very high and that is probably why adding more Low Max helped my system in the video (there was not enough voltage to activate valve)
EDIT:
Added the 12/24 V converter, and now it is much more responsive.
Had to turn down both Gain and minimum PWM quite at bit, as well as Low Max PWM.
Conclusion: it is not enough thinking, that turning up min PWM can make at 24 V valve work properly on only 12 V
Don’t pay attention to the parameter to the sheet: they are parameters for my test bench.
For my Fiat tractor I’ve: Gain 25, Min PWM 53, Hight Max 200. With thoses paramater, Low Max has no influances. I just set it to 75.
I want that Low Max has an influance, I have to change the angle in the INO. Perhaps I will try.
You can maybe also change the coils to 12v coils?
That would be possible too, but I already have the 12v to 24 v converter. So will try that first.
I just redid my setting starting as mentioned below. What a difference!! This tip needs to be included in setup documentation. Just my 2cents worth.
Yes, and test in both directions of rotation
Hello,
It’s cool if it could help you !
I think one improvement for AGO could be a “Minimum PWM determination mode”.
I think this mode could work like that:
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When this mode is engage, AOG drive the motor (left or right, to be choose by the user) with only the minimum PWM value. So AOG doesn’t take accound the WAS angle, and the error, and gain etc… AOG juste send the Min PWM (left or right) to the motor
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Before engaging this mode, the operator shall be in a field, and shall have positionned the steering wheel close to 0° angle. And set the PWM Min at a low value. Then the operator start to move the tractor, engage the motor and this specific mode. AOG will send the Min PWM command to the motor, but as we are in a low PMW value, the motor will not be able to turn the steering wheel. So the operator just has to increase the Min PWM value until a value where the motor is able to turn the steering wheel. Repeat the same on the other sight (if we start by turning left, repeat with turning right). And then the Min PWM is determined for this tractor and motor mounting.
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This specific mode is left by the operator, he has now determined the Min PWM value and doesn’t have to change it anymore. I can go trought the orther parameters (gain, ect…) with the existing “drive mode” to determinated the remaining parameters.
Math
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Maybe somebody can write a small sketch to be uploaded. That would not require any changes in AOG.