Research on the Multi-Point Gravity Balance Method for the Large-Aperture Space Camera in the Imaging Quality Test

Abstract

The large-aperture space camera needs gravity unloading in the ground imaging quality test. The multi-point gravity balance method is mainly applied to the object with symmetrical structure and regular mass distribution, such as the primary mirror of the space camera. There is no relevant research on whether large-aperture space cameras with large weight and low stiffness can be unloaded by a multi-point gravity balance system. Based on the equivalent statically determinate structure and the classical equation of force method, the load-solving method of a multi-point gravity balance system is studied. The mathematical model of a two-point unit and a three-point unit is established with the principle of force balance. The mathematical model of a gravity balance system is built with the unit-grouping principle. A 15-point gravity balance system of a large-aperture space camera is established. The displacements of the mirrors under the multi-point gravity balance system are much smaller than the displacements under the traditional support by the finite element analysis, which can realize the imaging quality test. The multi-point gravity balance method is effective on the space camera imaging quality test.