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Post by riton39 on Oct 8, 2014 17:31:25 GMT
can you tell me how you connect the oscilloscope and how you rule the oscilloscope to make the setting of PID? I can not do with my oscilloscope ... thanks
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Post by tronicgr on Oct 8, 2014 21:39:40 GMT
The oscilloscope probe is connected on the AMC1280USB on the same sensor input (S) on the pins or on the screw terminal and the ground (GND) of the board.
I think you meant to place this video instead:
Then you can increase the second setting on the oscilloscope (time base), to draw more slowly the curves of the measurement like on the video above.
Thanks Thanos
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Post by tronicgr on Oct 8, 2014 22:47:40 GMT
Connect the oscilloscope probe on the pin row "S" of the analog input on the AMC1280USB, and the potentiometer on the Screw terminal. The alligator clip on the probe is the GND.
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Post by riton39 on Oct 8, 2014 22:54:56 GMT
how to do that ? what is the parameter name in the scope? i try to decrease and increase but no curve... Then you can increase the second setting on the oscilloscope (time base), to draw more slowly the curves of the measurement like on the video above.
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Post by tronicgr on Oct 8, 2014 23:07:58 GMT
Yes, I think on my videos I set the second setting (timebase) to 100ms/div.
To see the curve, press the UP/DOWN/LEFT/RIGHT buttons on the AMC1280USB to change the position.
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Post by riton39 on Oct 8, 2014 23:15:11 GMT
ok, thanks, i try tomorrow
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Post by riton39 on Oct 21, 2014 19:59:55 GMT
I have great difficulty with the 'PID' .. with a P to 40/45 I have less dropped out when the cam that moves from the top to the center.
if P is around 30 When the cam goes down it goes down too low and back. with 40/50 is better
I will make a video.
I feel that I can find no good solution adjustment.
Is the lack of engine torque can be a reason difficulty settings?
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Post by tronicgr on Oct 21, 2014 21:17:04 GMT
Did you try to increase the Sensor Oversampling value to 2 or 4 (On the LCD menu)? It will stabilize better the higher P values (40/50).
Also for the over-shooting you describe, try to increase the D term... Increasing the D term will cut off the speed faster before it reaches the target (middle) and starts going over (down).
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Post by riton39 on Oct 22, 2014 16:35:21 GMT
I spend hours and hours and each time it's really not the top .... I wonder if I will continue with this thechnologie I will think, as I have in any case invest in 3 gear motors, I can go to take servo motors ...
I have a problem with my drive, I do not know how to adjust the curve U / F 'parameter to n 09 n15 (omron mini J7) if I change the values, it changes the PID is completely distorted!
it's hard to be on the setting of the drive. I changed to another setting, that to improve things, but there are so many parameters, are set correctly?
it's really a headache that PID
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Post by tronicgr on Oct 22, 2014 17:05:13 GMT
riton39Have you ever thought to use Worm Gearboxes? They behave much better under load and they don't back-drive the motor position because of the load. Then you can have good results even with under-powered AC motor... Servomotors will do the same thing under load, they will oscillate too if the load is trying to backdrive them, that will happen if the load is beyond their specifications (they correcting the position)... A good mechanical design can overcome such stability issues. I remember when I tried using the AC motor for FFB... I had to make lots of changes in the VFD inverter parameters, to limit the max RPM of the motor to 80RPM, then limit the max current used, and lower safety limits to allow the motor to be used in torque mode... www.youtube.com/watch?v=mmC9qn_osLcIf I can use an AC motor for FFB steering wheel, it can be used for anything!
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Post by riton39 on Oct 22, 2014 18:25:13 GMT
I am not able to make a correct setting is that possible ??
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Post by tronicgr on Oct 22, 2014 18:50:29 GMT
riton39Ok, from quick looking at the settings you have: Change to: P=50 I=0 (This parameter produces a "kick" to the motor to make it reach the correct position if there is offset for significant amount of time, thats why you see it kick back up every now and then). D=40 (try to increase or decrease from this value to see the difference.) On-line speed = 80 Off-line speed = 80 (or 75 or less), try to decrease it until no notion occurs in target position. Also go to the "6DOF Start Pos" menu and change the "step speed" to 99 And under same menu, "Timeout" to 9 Then, while trying the motion on the motor, Turn OFF the LCD display (yellow dip switches, 1st switch OFF position) (turn on again for more settings). I'll have to address the LCD update thing to be able to disable itself a few seconds of no activity on the encoder of the menu... Lots of people leave the LCD updates on and then the motor really shakes as of the PID timing distortions that introduced by interrupting the PID code to display info on the LCD. Thanks Thanos
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Post by tronicgr on Oct 22, 2014 18:52:43 GMT
Another question...
If you power off the motor, can you move the arm with your weight? Does it go down (backdriving the motor?)
Thanks
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Post by riton39 on Oct 22, 2014 18:57:32 GMT
My dealer told me that the engine had more games the gearwheels output. they are least as strong as those made of cast iron.
I do not know what to do ...
CKAS uses the same engine as me.
maybe my motors do not have enough torque. Then there are potentiometers ...
I have a problem with the V / F, I do not know if my parameter setting is correct.
I will try with my other inverter ABB to see if the behavior is different.
I read something about the PID autotuning? a track can be?
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Post by riton39 on Oct 22, 2014 19:12:54 GMT
Another question... If you power off the motor, can you move the arm with your weight? Does it go down (backdriving the motor?) Thanks if I cut power to the motor I can move the cam in hand, but it's heavy! about 40 kg without the driver. but I can lift! super riton
with the load, the cam rotates back and exceeds the value of the potentiometer, I had to put a mechanical stop. (wood)
tomorrow I lists the settings that you recommend.
I changed the settings tonight curves U / F, and my PID settings are completely different now, the result is not at all the same as the video.
I understand and optimize the setting U / f or I'll never get there.
that's a lot of parameters.
I saw that the behavior is different between the high, low and center position. sometimes the PID is correct bottom-center and bad from top to bottom or vice versa ....
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