Abstract
Fast steering mirrors (FSMs) are used to correct images observed by satellites. FSMs need to have large apertures and realize high precision and the positioning of the mirror in the tip-tilt and axial directions needs to be highly precise and highly responsive in order to capture large-scale, high-resolution images. An FSM with a large-diameter mirror supported by a compact magnetic suspension and driven by long-stroke voice coil motors (VCMs) is proposed in this paper. The magnetic suspension and VCM actuators enable the mirror to be highly responsive and to have long-range movement in the tip-tilt and axial directions without friction and wear. The magnetic suspension is a hybrid that has active control in the lateral directions and passive support in the tip-tilt and axial directions. An experimental FSM with an 80 mm diameter dummy mirror was fabricated and tested. The mirror’s driving ranges in the tip-tilt and axial directions were ±20 mrad and ±500 μm, respectively. Furthermore, the servo bandwidths in the tip-tilt and axial directions were more than 1 kHz and 200 Hz, respectively.
Highlights
Earth observation and astronomical satellites for acquiring larger-scale, high-resolution images have been developed [1]
Rapid response of a large mirror is usually difficult to realize because the larger the mirror is, the more vibration modes the Fast steering mirrors (FSMs) has in the low-frequency range
We propose an FSM using a magnetic suspension to guide the mirror in the tip-tilt and axial directions and suppress other low-frequency vibration modes
Summary
Earth observation and astronomical satellites for acquiring larger-scale, high-resolution images have been developed [1]. Electromagnets and laminated piezoelectric actuators generate a large force, but the stroke is smaller than that of a VCM, and non-linearity such as hysteresis and saturation is Electronics 2020, 9, 1997; doi:10.3390/electronics9121997 www.mdpi.com/journal/electronics diameter mirror. The mirror is supported by a magnetic suspension with two degrees of freedom (DOF) control, and is driven by high response VCMs. The targets for the positioning ranges in the tip-tilt and axial directions are set to be more than ±17.4 mrad and ±500 mm, respectively. Linearity andguided have a larger positioning range than piezoelectric actuators or electromagnets [5,6,7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
