Quantitative feedback control of a linear positioning stage with cogging force compensation

Quantitative feedback control of a linear positioning stage with cogging force compensation is presented. Positioning stage direct-driven by linear motors commonly suffers from significant mechanical resonances at high acceleration rates. Which is solved by using a tracking control scheme based quantitative feedback theory (QFT). Cogging force deteriorates significantly positioning accuracy and tracking accuracy of positioning system employing a permanent magnet linear motor (PMLM). A fully experimental method for cogging force calibration is developed. The compensation for cogging force is also proposed under combination of a QFT controller. Experimental results under cogging force calibration are shown, and the comparisons of tracking errors with and without cogging force compensation are also given. The experimental results demonstrate the feasibility and effectiveness of the proposed methods.