Dual Motor control with electronic gearing

[christianwaldmann9]

Posted on July 23, 2014 at 17:54

I am using the FOC SDK 4.0 and have set up a dual motor control system with a STM32F405 controller. The motors are PMSM and have a quadrature encoder each.

Now I want to drive the motors in parallel with electronic gearing. One Motor is the master and the other follows the rotation position with a variable gear ratio.

To do so, I want to count the number of steps and rotations of the motors. 

How can I use the FOC SDK to get this information?

If I have the absolute position of both motor, I can control the slave with execSpeedRamp to reach the requested position. But It would be easier to have a ''position generator'' that sets the requested mechanical position of the slave.

Is there an app note or an example to realize this kind of position control?

#pmsm-electronic-gearing

[Giuseppe Scuderi]

Posted on July 24, 2014 at 15:54

Hello,

it is possible toread the

mechanical angle

from encoder through the following MC APIs ->  “int16_tSPD_GetMecAngle(CSPD this)�?.  Before I suggestto use MCT_GetSpeednPosSensorMain(oMCT) or equivalent MC API in order to get the CSPD localreference to put inside the previous function.

The GetMecAnglereturns the value in s16 format. In one mechanical rotation, the s16 formatvariable changes value two times.

Unfortunately FOCSDK 4.0 doesn’t have a position control block inside but now we are developingan algorithm to provide it with different speed profile. It will be providedin the next release of SDK together with the technical documentation.

Regards,

Giuseppe

[Laurent Ca...]

The question has been moved from the "Motor Control Hardware" section to the "STM32 Motor Control" section (the question is about the STM32 MC SDK). 

Best regards