이동통신 단말기 카메라의 손떨림 보정 장치의 H∞ 제어

This study proposes a closed-loop shaping control method with H∞ optimizationfor optical image stabilization (OIS) in mobile phone cameras. The imagestabilizer is composed of a horizontal stage constrained by ball bearings andactuated by the magnetic force from voice coil motors. The displacement of thestage is measured by Hall effect sensors. From the OIS frequency responseexperiment, the transfer function models of the stage and Hall effect sensor wereidentified. The weight functions were determined considering the trackingperformance, noise attenuation, and stability with considerable margins. The H∞optimal controller was executed using closed-loop shaping and limiting thecontroller order, which should be less than 6 for real-time implementation. Thecontrol algorithm was verified experimentally and proved to operate as designed.