Space infrared sensor must be assembled on a small satellite platform, so its whole mass and structure dimensions are
strictly restricted by the satellite platform. The mechanical structure must be compacted, light, handy and reliable. Task
of space infrared sensor structure system is to integrate each parts of system and provide a stable and reliable work
platform for the whole body. The transfer functions of flexible object and base are analyzed by using mechanical
impedance method and compared with stiffness models. It indicates that space infrared sensor must be considered the
flexible body influence for transfer function on some certain conditions. Using second order Krylov method expresses
multi-DOF flexible substructure, which combines with modal synthesis method to model and analyze two substructures
connecting with springs and dampers. Compared with direct FEM arithmetic, it can improve the calculation efficiency
and handle variable-rate stiffness and damping model or complex stiffness model of flexible connection, which is cannot
do for common commercial FEM software.
With the uprating requirements of space remote sensing, the aperture of the optical remote sensor is getting larger and larger. The influences of both the support of optical elements and gravity deformation on the optical system are difficult to conquer. Therefore, it is necessary to compensate the descending optical performance which is caused by the surface error of primary mirror by means of adjusting the position parameters of the optical elements on-orbit. A large aperture coaxial three-mirror optical system is introduced in the paper. Matlab and MetroPro are used to simulate the surface error of the primary mirror. The surface error of the primary mirror is compensated by adjusting the position freedoms of the secondary mirror. The results show that the adjustment of the position freedoms of the secondary mirror can compensate both the coma and some astigmatism of the primary mirror, but not the spherical aberration.
A new style calibration mechanism is designed for the infrared camera working in space. This calibration mechanism adds a locking device, which will produce magnetic force to fix the moving parts on the stage of launch. It has not been taken into account in past calibration mechanism of space infrared camera. In order to simplify structure and control system, an alnico is adopted in locking device as the source of magnetic field, which interacts with magnetic material and produces locking force. In addition, there is also a special structural design, which makes magnetic circuit closeitself to control magnetic leakage interfering with other equipment. Besides, another important component of calibration mechanism is a permanent magnet torquer. It can provide driving force for the blackbody to complete two state conversions of calibration and Non-calibration. High magnetic induction intensity and coercivity alnico is used as the stator, which will lighten the weight of torquer. On-off control strategy is selected in order to simplify the control system. Because calibration is only a temporary state, temperature rise has little influence on torquer. This setup is favorable to increase its reliability. There are guard plates on the axial direction shielding electromagnetism, also reducing magnetic leakage. Experimental investigations have been carried out to verify the feasibility and reliability of design. Result indicates the calibration mechanism can primely complete the calibration task of the space infrared detector. It has an important application value on the field of infrared detection.