A Fast Steering Mirror Driven by Voice Coil Motors and Supported by Magnetic Suspension

Abstract

Fast steering mirrors (FSMs) are mounted on observation satellites to capture large-scale and high-resolution images. In order to get high quality image correction, FSMs need to have large apertures, high responsivity and multiple degrees of freedom control. In this paper, we propose a FSM that has a large-diameter mirror driven by four voice coil motors and is supported by a compact magnetic suspension system enabling it to have fast response and long-range movement not only in the tip-tilt directions but also in the axial directions. A prototype FSM with an 80 mm diameter dummy mirror was built. The mirror is supported by a magnetic suspension system having six degrees of freedom. The suspended mirror is controlled by the VCMs and the driving ranges in the axial and tip-tilt directions are ±500 µm and ±20 mrad, respectively. Furthermore, the servo bandwidths achieved in the tip-tilt directions are more than 1kHz.