Precision evaluation method for the sub-reflector adjustment mechanism of Shanghai 65 meters radio telescope

In this paper, the configuration of the sub-reflector adjustment mechanism of Shanghai 65 meters radio telescope is introduced, and the kinematics calibration is performed by the laser tracker for institutions. Secondly, based on the strong coupling characteristics of the parallel mechanism, a method contains a coupled repeated positioning accuracy information is proposed which is suitable for the parallel mechanism repeated positioning accuracy measurement and evaluation. Finally, according to the proposed repeated positioning accuracy measurement and evaluation methods, the uniaxial repeated positioning accuracy and spatial pose repeat precision of the adjustment mechanism of sub-reflector are measured and analysed. The results show that the repeated positioning accuracy of the adjustment mechanism of sub-reflector is high and is able to meet the requirements of the pointing adjustment precision of the sub-reflector of 65 meter radio telescope.