Parameter setting for Motor control In FreeMaster

nxf63743 — Wed, 12 Aug 2020 12:20:18 GMT

I am working on motor control for igus MOT-EC-60-CIA (NEMA24) motor using RT1050-EVK-B and FRDM-MC-LVPMSM. I need some clarify on parameter setting in free-master to tune the motor.1) Should I set the parameters according to the motor datasheet? (As I tried setting the similar parameter, the measured motor parameters is not same as the datasheet). Measuring mechanical parameter is not showing complete.

2)My requirement is high torque. Where do I set the position setting for the encoders?

i.MX RT‌FreeMASTER

Re: Parameter setting for Motor control In FreeMaster

Zbynek_Mynar — Thu, 13 Aug 2020 12:04:08 GMT

Hi Aditi,

Regarding the datasheet parameter usage:
You can definitely use motor parameters from the datasheet. That being said, you will need to convert them to dq-axis parameters expected by MCAT first (notice, that your datasheet, for example, states phase inductances) - this is also probably the reason why parameters identified by MCAT do not match datasheet parameters. You can check the AN4986 document, which describes manual parameter measurement, as well as calculation of parameters expected by MCAT. Once you are done, you can enter the converted parameters in the Parameters tab (but you already probably know that).
Regarding the failing mechanical parameter measurement:
You can read more about the mechanical parameter identification in section 9 of the 3PPMSMCRTUG document (it should be included in the documentation archive for your SDK pack - see MCUXpresso SDK Builder).
We should distinguish between large moments of inertia J and a large load torque Trq_load. If you have a large external loading torque Trq_load applied to your rotor during measurement, then, unfortunately, the measurement method might fail - it is expected, the rotor is "freewheeling" during the measurement and that your motor is the only on applying significant torque - see the equations in 3PPMSMCRTUG. If you have failing measurement with a large moment of inertia J connected to your rotor, then:
- Your electrical parameters are must be correct first (BEMF observer is used to estimate the speed during this measurement).
- You might need to increase the measurement toque (Trqm in MCAT Motor Identif tab) if the rotor does not spin up and down smoothly.
- Double-check the nominal speed value is correctly set (rotor speed must reach at least 50% of the nominal speed, otherwise the measurement will fail
The encoder setup:
The configuration of the encoder driver is in the Sensors MCAT tab. Once you set it up correctly, you can set the position control loop setpoint in the Control Struc tab (in the Pos_req field). You can read more about the encoder sensor setting in section 9.4 of the 3PPMSMCRTUG document (it should be included in the documentation archive for your SDK pack - see MCUXpresso SDK Builder).

I hope that helps.

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Parameter setting for Motor control In FreeMaster

Re: Parameter setting for Motor control In FreeMaster