We are trying to control a 24V PMSM using ST Motor Control Workbench (MCW) version 6.3.1 with the FOC in order to control a sliding door. We are using “Position Control” as the control mode.
We are using Nucleo-G474RE, STEVAL-IHM023V3 and X-Nucleo-IHM09M2 boards.
PMSM has 10 pole pairs and there is a 1024 ppr incremental quadrature encoder on it.
So far so good, but recently we noticed that in some cases the encoder alignment was not complete. Namely; when the sliding door is completely closed and we energize the motor, the encoder cannot align and motor stucks. However, when we do the same process with a minimum 5 mm gap, there is no problem.
From what we understand here, in order to align the encoder, the rotor needs to be rotated a little depending on the position of the magnets and therefore the rotor. We consider this issue to be a situation that may be encountered during normal use.
Do you have any advice?
Would changing any parameters in the Speed Sensing Configuration step of the MCW software be a solution? If yes, how?
Since the nature of FOC control requires aligning the encoder and rotating the rotor to achieve a 90 degree angle, can the algorithm be improved to align the encoder at the limit points where the rotor can initially only rotate in one direction? Can ST experts evaluate and respond to this issue?
Would using an absolute encoder instead of an incremental encoder be a solution?
Thanks in advance for your support.
