Research of speed ripple reduction method for computed tomography

This paper presents a study on the high performance speed control of permanent magnet synchronous motor for a computed tomography (CT). In a CT system, many units are attached on the rotational part of the gantry, such as x-ray tube, detector, collimator, and data acquisition system. Therefore, it is difficult to balance many components of different weights; this is inevitable problem in CT systems. To reduce speed ripple caused by eccentricity, this study proposed modified adaptive eccentricity compensator (modified AEC) and verified its validity by comparing it with load torque observer (LTO).