A fiber positioner robotic arm with sensor based on 4 mm motor

The fiber positioner robot is the most crucial actuator in the focal positioning system of a Multi-Object Spectrographs. The double-rotation form of fiber positioner was first extensively used in the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST) in 2012. However, as multi-spectral telescopes continue to develop, there is a growing demand for smaller and lighter fiber positioners. Current focal positioning systems are now considering the use of 4 mm motors, which are smaller than stepper motors. However, these motors do not come with a position sensor solution. Researchers have developed a miniaturized position sensor solution compatible with this motor, and it is installed in the center arm of the fiber positioner. Prototypes have been fabricated and, in conjunction with relevant experiments, this paper provides a detailed introduction to the specific impact this angle sensor has on the fiber positioner.