Implementation of Discrete Fourier Transform in Mechanical Analysis of a Servo Drive System

Servo drive systems may have mechanical resonances and anti-resonances that degrade the total system performance. This paper utilizes discrete Fourier transform to obtain a Bode plot of a mechanical part of a drive and to get resonance and anti-resonance frequencies. It was shown that the average speed of the motor is close to zero during the measurement, so that method can be safely used with a fragile load on the shaft. In contrast to other solutions, that method allows to obtain information quickly and analyze the system performance at a high range of frequencies. The obtained Bode plot can be used to set digital filters according to resonance and anti-resonance frequencies. The experiments proved that it is possible to measure frequency response at frequencies up to 10 kHz.