This example shows a motion control system step response. The rotation angle of the load shaft is being controlled using a permanent magnet synchronous machine (PMSM) for actuation. The motor drive includes a sampled-data D-Q control algorithm and space-vector modulated (SVM) inverter. The rotational load includes simple (linear) inertia and viscous drag, as well as non-linear "stick - slip" friction effects.
The waveform plot in the upper left shows the closed-loop system step response, with the commanded angle in radians (light blue waveform) and the corresponding load shaft angle (green waveform). Note the overshoot and ringing behavior indicates a potential concern for system stability. This is analyzed further using the TDFS method, in the companion design "TDFS Open-Loop Frequency Response for PMSM/SVM Motion Control System".