speed measurement resolution

[sjson]

Hello.

I am currently conducting FOC (Field-Oriented Control) tests using the Motor Control Workbench with the Nucleo-G431RB board and the IHM08M1 power stage.

My target speeds are 300 rpm and 150 rpm.

However, when using Hall sensors with motors that have 4 and 8 pole pairs, the measured speed resolution appears to be limited to 6 rpm.

Initially, I suspected this limitation was due to the resolution of the Hall sensors.

However, even after switching to incremental encoders (1024 PPR and 8192 PPR), the measured speed still increments in 6 rpm steps.

Is there any method to enhance the speed measurement resolution in this setup?

[GMA · Accepted solution]

Hello @sjson,

The reported RPM value uses the following computation (refer to register_interface.c):

/** Revolutions Per Minute: 1 Hz is 60 RPM */
#define U_RPM 60
/** Tenth of Hertz: 1 Hz is 10 01Hz */
#define U_01HZ 10
MCI_GetAvrgMecSpeedUnit(pMCIN) * U_RPM) / SPEED_UNIT);

 You can add an RPM value filtering to the reported values.

[sjson]

Thank you