Synthesis methods of high precision motor servo system control

The studies were implemented for the core problems on controller design of high precision motor servo system. A differential estimation method was proposed based on the basic idea of nonlinear tracking-differentiator, as well as its discrete realization of the simplest format. According to the small gain theorem, the order number influence of the low-pass-filter was discussed for disturbance observer (DOB) synthesis, besides, the synthesis rule was proposed. It was also discussed on the design methods and applicable areas of zero phase error tracking controller (ZPETC) and perfect tracking controller (PTC). By utilizing the insensi-tive characteristic for signal aberrance of the proposed differential estimation, an equivalent velocity+accel-eration feedforward scheme was designed. Numerical analysis and simulation experiments are as follows: compared with traditional difference, the differential estimation gets differentia value effectively even there is noise and aberrance; the cutoff frequency of DOB can be improved through the order design of the low-pass-filter; compared with ZPETC and PTC, the proposed feedforward decreases the tracking error to 0.02° for 5 Hz sine command, even there is command aberrance.