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Post by paulg100 on Oct 23, 2016 8:55:13 GMT
My P is currently 22 and I is 177 I'm not using any D at present, that comes last for final touch, although I gather some techniques can calculate PID by tuning D first. I have a small difference in I for some of the motors (with new firmware)
I'm pretty happy with these settings, response is good with this on my sim with fast accurate return to home and no hunting.... with one motor running.
The more motors/VFD's I activate then my problems start due to EMI I think... I need to make some videos to show where I am with things.
Fortunately you didn't use VFD's so should be easier for you.
I was never able to get good results with Fabis autotune so far.
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Post by tronicgr on Oct 24, 2016 0:13:37 GMT
I'm not sure if it is the same issue. All i know that after many hours of experimenting with PID , in order to improve response and achieve better repeatability of position. What "P" value you've reached without "hunting" on the arms?? In my case I can not get clean response with value higher than 15.
As I made now all possible efforts to isolate the sensors from noise, I am searching for a parameter which would aloud me to go with a higher "P"
It is really easy to get lost in this jungle of parameters.
cheers
The Clearpath motors you use, need to be adjusted to work similar to vfd inverters with access motors. See these videos how you can change their behavior via their setup utility: youtu.be/4WUqyzt8tEYyoutu.be/MAAoWksO1M8Thanks Thanos
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Post by hexpod on Oct 24, 2016 0:23:26 GMT
What "P" value you've reached without "hunting" on the arms?? In my case I can not get clean response with value higher than 15.
As I made now all possible efforts to isolate the sensors from noise, I am searching for a parameter which would aloud me to go with a higher "P"
It is really easy to get lost in this jungle of parameters.
cheers
The Clearpath motors you use, need to be adjusted to work similar to vfd inverters with access motors. See these videos how you can change their behavior via their setup utility: youtu.be/4WUqyzt8tEYyoutu.be/MAAoWksO1M8Thanks Thanos Thanks for the response. Of course I've watched those many times. I will analyze again.
My hunting problem occurs with all motors simultaneously ONLY when their position is at 73 and 74 percent. they are getting crazy there. Everywhere else they are quiet.
Is this not strange??
cheers
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Post by tronicgr on Oct 25, 2016 10:56:53 GMT
The Clearpath motors you use, need to be adjusted to work similar to vfd inverters with access motors. See these videos how you can change their behavior via their setup utility: youtu.be/4WUqyzt8tEYyoutu.be/MAAoWksO1M8Thanks Thanos Thanks for the response. Of course I've watched those many times. I will analyze again.
My hunting problem occurs with all motors simultaneously ONLY when their position is at 73 and 74 percent. they are getting crazy there. Everywhere else they are quiet.
Is this not strange??
cheers
Hmm, this could be the Clearpath reading wrong the PWM signal at that point. I remember there was a setting in the Clearpath for the frequency that could be responsible for this... did you choose low frequency output clearpath mode from the amc1280usb lcd menu?
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Post by hexpod on Oct 25, 2016 11:47:38 GMT
Thanks for the response. Of course I've watched those many times. I will analyze again.
My hunting problem occurs with all motors simultaneously ONLY when their position is at 73 and 74 percent. they are getting crazy there. Everywhere else they are quiet.
Is this not strange??
cheers
Hmm, this could be the Clearpath reading wrong the PWM signal at that point. I remember there was a setting in the Clearpath for the frequency that could be responsible for this... did you choose low frequency output clearpath mode from the amc1280usb lcd menu? I was sure that those frequency parameters are active only when pulse-burst mode is activated. It's not my case. I've set the platform on the shaking spot and I tried all frequency values from the AMC. I did NOT noticed any improvement.
cheers
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Post by hexpod on Oct 25, 2016 21:23:08 GMT
"did you choose low frequency output clearpath mode from the amc1280usb lcd menu?" Now yes! but it did not helped at all.
I've double checked everything....no success.
"I remember there was a setting in the Clearpath for the frequency that could be responsible for this" Please be more explicit. I don't see which setting are you talking about.
"this could be the Clearpath reading wrong the PWM signal at that" In your tests, you've never tested the PID with clearpath at different positions. did you?
I can also set the PID accurately for a certain position. The problem starts when you want to hold another positions all across the lever course.
vimeo.com/188894750
Starting to desperate.
cheers
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Post by tronicgr on Oct 26, 2016 11:11:17 GMT
"did you choose low frequency output clearpath mode from the amc1280usb lcd menu?" Now yes! but it did not helped at all.
I've double checked everything....no success.
"I remember there was a setting in the Clearpath for the frequency that could be responsible for this" Please be more explicit. I don't see which setting are you talking about.
"this could be the Clearpath reading wrong the PWM signal at that" In your tests, you've never tested the PID with clearpath at different positions. did you?
I can also set the PID accurately for a certain position. The problem starts when you want to hold another positions all across the lever course.
vimeo.com/188894750
Starting to desperate.
cheers
I'll test the PWM today on oscilloscope to see if there is any noise there. I also got hold of a pca9685 PWM chip that has 12bit resolution and can be attached on the i2c inputs of the amc1280usb. I'll try that as well. I also just ordered a SSI sensor from digikey just now. I haven't heard back from the other company you suggested. Thanks Thanos
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Post by hexpod on Oct 26, 2016 11:33:12 GMT
"did you choose low frequency output clearpath mode from the amc1280usb lcd menu?" Now yes! but it did not helped at all.
I've double checked everything....no success.
"I remember there was a setting in the Clearpath for the frequency that could be responsible for this" Please be more explicit. I don't see which setting are you talking about.
"this could be the Clearpath reading wrong the PWM signal at that" In your tests, you've never tested the PID with clearpath at different positions. did you?
I can also set the PID accurately for a certain position. The problem starts when you want to hold another positions all across the lever course.
vimeo.com/188894750
Starting to desperate.
cheers
I'll test the PWM today on oscilloscope to see if there is any noise there. I also got hold of a pca9685 PWM chip that has 12bit resolution and can be attached on the i2c inputs of the amc1280usb. I'll try that as well. I also just ordered a SSI sensor from digikey just now. I haven't heard back from the other company you suggested. Thanks Thanos Excellent! Thank you
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Post by hexpod on Oct 26, 2016 13:00:53 GMT
I'll test the PWM today on oscilloscope to see if there is any noise there. I also got hold of a pca9685 PWM chip that has 12bit resolution and can be attached on the i2c inputs of the amc1280usb. I'll try that as well. I also just ordered a SSI sensor from digikey just now. I haven't heard back from the other company you suggested. Thanks Thanos Excellent! Thank you For the good vibration ability, I have the feeling that motor acceleration around 6000rpms and controller P around 25 is needed. Please consider this when testing with scope. If you can get a steady response, than the goal is reached.
cheers
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Post by tronicgr on Oct 29, 2016 15:23:00 GMT
I tested on my small DC motor (12v) and didn't see any noise or unstable position. The PWM signal was clean as well for 31khz and 4khz settings.
It could be the Clearpath failing to capture certain pulse ratio. I'll have to test on my actual Clearpath motor to see if I can replicate this.
On other testing of the i2c 12bit pwm chip and the ssi sensor, I will be receiving the ssi sensor today, but I'll be testing these by Monday or Tuesday as I'm moving my lab this weekend.
Thanks Thanos
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Post by paulg100 on Oct 29, 2016 16:04:21 GMT
Will you be able to test the new chip and sensor with a VFD or better still multiple VFD's?
all my problems really kick in when multiple vfds are running.
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Post by hexpod on Oct 30, 2016 18:14:38 GMT
I tested on my small DC motor (12v) and didn't see any noise or unstable position. The PWM signal was clean as well for 31khz and 4khz settings. It could be the Clearpath failing to capture certain pulse ratio. I'll have to test on my actual Clearpath motor to see if I can replicate this. On other testing of the i2c 12bit pwm chip and the ssi sensor, I will be receiving the ssi sensor today, but I'll be testing these by Monday or Tuesday as I'm moving my lab this weekend. Thanks Thanos Make it sense de develop the "bipolar PWM" or "frequency input" mode for the AMC in order to be able to use the PWM dead band??
www.teknic.com/files/downloads/clearpath_user_manual.pdf
That could maybe give us a great option to make the arms steady.
cheers
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Post by clyevo on Nov 11, 2016 10:41:52 GMT
From another series of stupid questions...
needs the AMC to be extra grounded? or the ground from the usb is enough?
cheers
If you need better ground connection, you should connect a known good ground to the ground pins on the terminal of the 6dof ext board. This is more important for VFD applications that use analog signal that is delivered by this extension board. The AMC1280usb itself has good grounding via the computer USB she'll. Thanks Thanos "a known good ground" you mean like the earth wire on the AC power line? My AMC board chasis is connected to earth, is it ok to connect the ground terminal of the AMC to the chasis for better grounding to reduce interference?
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Post by tronicgr on Nov 11, 2016 15:26:17 GMT
If you need better ground connection, you should connect a known good ground to the ground pins on the terminal of the 6dof ext board. This is more important for VFD applications that use analog signal that is delivered by this extension board. The AMC1280usb itself has good grounding via the computer USB she'll. Thanks Thanos "a known good ground" you mean like the earth wire on the AC power line? My AMC board chasis is connected to earth, is it ok to connect the ground terminal of the AMC to the chasis for better grounding to reduce interference? You connect the ground from the 6dof ext board to the vfd, but you have to make sure the vfd is also grounded too seperately to avoid any leakage of current via the ground of the amc1280usb... the USB cable should not carry the ground of the vfd! Otherwise you may get zapped every time you touch the amc1280usb. Seen it before in person happening. Thanks Thanos
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Post by tronicgr on Nov 11, 2016 15:33:45 GMT
I finally got the ssi sensor wired. it's really hard unless you order the specific microblade connector and pre crimped wires. I'll also have to fix it to an axle or something. it's designed to mount on a motor so I'll have to 3d print a mount for manual testing during programming it. I 3d printed already some mounting tools for it. Thanks Thanos
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