freemaster problem mcat encoder

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freemaster problem mcat encoder

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michelet1
Contributor II

hello, I'm trying to use MCAT project (download from SDK) with power board MC-LVPMSM and evaluation board rt1050evkb.

if I use the teknic motor with encoder everything works perfectly.
Now I'm testing with the RPX52 electrocraft engine and the problem is that the speed found with the encoder is much higher than the real sensorless speed.

I am attaching a screen that better explains my current situation in which I run my motor in sensorless and analyze the speed read with the encoder and I would expect the two speeds to be similar

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_Leo_
NXP TechSupport
NXP TechSupport

Hi @michelet1,

Thank you so much for your interest in our products and for using our community.

Since the encoder of the RPX52 ElectroCraft BLDC motor has a different resolution than the Teknic M-2310P motor, it is necessary to set the encoder parameters in the "Sensors" tab.

nxf86756_0-1668448910763.png

Hope it helps you. Please let me know if you have more questions about it.

Have a nice day!

Best regards, 
Leonardo

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1,140 Views
michelet1
Contributor II

Hi Leonardo,

Thank you for your answer.
I tried to modify these parameters properly but the problem seems to be already present in the LPOS register of the i.mx QuadEnc peripheral.

At certain times this device no longer updates the pulse value.
We have analyzed the A and B signals of the motor encoder with an oscilloscope and it would seem that in some instants the 90° phase shift between the A and B signals is lost.

Thanks, Michele

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_Leo_
NXP TechSupport
NXP TechSupport

Hi @michelet1,

I'm noticing that the encoder resolution of the RPX52 ElectroCraft BLDC motor is 5000 pulses, while that of the Teknic M-2310P motor is 1000. I want to think that this resolution at high speeds is not supported by the encoder module of the device, however so far I can't find the specifications techniques of the latter. On the other hand I see that you are testing at 220-240 RPM. Could you please reduce the speed of the motor, for example, to 40 or 50 RPM to see if the A and B signals are still lost and share your results with me?

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1,183 Views
michelet1
Contributor II
 
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