Fast servo control and vibration suppression based on optical ZPETC and ZPNF

In this paper, a new scheme based on an optical zero phase error tracking controller (ZPETC) and zero phase error notch filter (ZPNF) is proposed. ZPETC is a method of feed-forward controller with effects that tracking speed of a position servo accelerated and system stability guaranteed. As the bandwidth of system includes the characteristic of gain and phase, ZPETC improves phase bandwidth greatly but the performance of gain bandwidth deteriorates slightly. So that a gain correction controller (GC)was introduce ahead of ZPETC to compensate the deterioration of the gain. Generally, ZPNF is adopted in two-mass system. ZPNF is a method of non-casual filter with effects of vibration eliminating for position servo on its load end and has less phase lag when compared with a normal notch filter. In proposed scheme, ZPETC and ZPNF are cascaded ahead of the position control loop. Simulation results on a two-mass PMSM system indicates that, a combination ZPETC and ZPNF improves both the tracking and positioning performance for a position servo system.