SimpleFoc Sensor Eccentricity Calibration

Antun_Skuric · March 12, 2025, 10:00am

Hi guys,
I’ve done an iteration in the @marethyu code of the CalibratedSensor in the drivers repo.
Now it supports steppers too. Its a bit more flexible in terms fo the Lookup table size and allows to load the LUT form the code and skip the calibration.

I find it very useful for stepper motors. I had a lot of trouble aligning the magnetic sensors with steppers due to the high number of pole pairs. Even with relatively precise 3d printed parts.
This code helps a lot

There are some examples in the examples folder as well and a bit more info in the README

Before the calibration:

After the calibraiton:

Here is the link to the PR:

github.com/simplefoc/Arduino-FOC-drivers

Extension of the CalibratedSensor

dev ← feat_stepper_calib

opened 09:30AM - 12 Mar 25 UTC

askuric

+421 -235

This is an extension of the existing CalibratedSensor code that makes it much mo…re flexible. - It supports both BLDC and Stepper motors, even maybe HybridSteppers - didn't try it - It allows for setting any LUT size - It allows to load the LUF from the code and skip the calibration I had a lot of trouble with magnetic sensors and stepper motors. Even with 3d printed parts I was never able to completely remove the missalignment, there was always some variation in the motor's torque. With this code, it is very well eliminated. And even if the sensor is not perfectly positioned, the torque output is very nice and smooth. I've tested both voltage and current control and they both work well, at least in my case. **LIMITATION** The limitation though is that the misalignement error should be within the electrical revolution range (for example if using NEMA 17 it should not exceed 360/50 = 7.2 degrees). So this still means that the sensor should be reasonable well positioned.