I am quite new Digital Signal Processing .I am trying to implement anti-cogging algortihm for my PMSMpermanent magnet synchronous motor (=PMSM) control algortihm. I follow this documentation
I collected velocity data according to the rotation angle. I have buffer with 1024 byte sizebytes long sampling buffer. Each index meansample is stored when my rotation encoder gave a pulse, so each index actually means mechanical rotation angle. And eachEach stored value is the velocity withat related mechanical angle.
I transported this buffertransformed the collected samples to frequency domain with FFT. WhatIt's not clear to me what is my Fs (sampling=sampling frequency). When iI examined tothe frequency spectrum , dominant harmonics are related multiplies of 14 - 27 index numbers which is number of slot(27) and number of pp(14).
But the last step of the suggested method, Acceleration Based Waveform Analysis , Itneed calculated derivative of FFT outputs with respect to time. Outputs are in frequency domain, so how could I calculate derivative of FFT outputs with respect to time , and why does it dothe method need this calculation?