The Calibration System And The Key Technique Research Of Deep Space Navigation Sensor

Optical navigation sensor is the special equipment of the precise navigation for the aircraft. Using of the optical system of navigation sensor, the photoelectric detector target surface can obtain the different imaging of the space target. Through the digital processing technology of digital image, the attitude calculation unit of navigation sensor can obtain the quasar center vector, orbit height and inertial attitude used for the aircraft navigation by the extraction of standard target table. Through the above operation can achieve the precise navigation of the satellite spacecraft. So it is so important to the optical navigation sensor that we must to calibrate the optical navigation sensor to get the precision value of the navigation sensor on the ground before the actual operation. At present the precision of the ground calibration using in the domestic and foreign methods can reach10" or so,which cannot meet the calibration requirement to deep space sensor that the star included angle accuracy is≤1".By analyzing the technical shortcomings using the existion conventional calibration system in the high precision optical sensor calibration,we research the the deep space navigation system and its technology,and put forward a new kind of the calibration method of the high precision optical sensor.Finally,we design the sensor calibration system based on the above presented method can realize the star included angle accuracy≤1",the magnitude5～10.The designed calibration system can simulates the high precision static variable standard star map,so the practical problem that the conventional calibration equipment performance cannot meet the calibration to the ddp space navigation sensor.We present the overall scheme of calibration system of deep space navigation sensor in this paper,and then constrcures and the principle of the calibration system are introduced.The calibration system is mainly composed of the high precision parallel light pipe and the high precision star charts simulator. In order to achieve the precision of the wave aberration, chromatic difference of magnification and distortion on the full field of view and the full spectral range, the simulator uses in the long-focal distance, large field projection optical system. The star charts simulator is introduced based on the method that combing the lighting system using the OLED,optical fiber and self-focusing lens as the optical coupling mechanism with the high-precision target. The work principle of the designed calibration system is that the simulator receives the different star map through the changing the star position and brightness, and projects the infinite variable standard star map to the entrance pupil of the sensor in accordance with the size of the sensor field, such realizing the different astrological charts in space to the sensor on the ground.We detailed design the mechanical mechanism of the calibration system based on the designed optical system.In view of the simulation requirements of the long focal length mechanical structure features and the weak target simulation,the collimation focusing mechanism is designed to ensure the target source located in the theory focal plane of the optical system.At the same time in order to reduce the overall system size,the steering mirror,which designed using of the micro stress clamping method to elimination the light shift and beating resulted from the reflector deformation and the vibration, is fixed in the system optical path.The overall sectional structures are connected by soft connection to facilitate the assembly and reduce the vibration influence because of the large strcture.Studying the key technology about the machine structure of the large size, high-precision star simulator, The controllable axial conformity for opt-mechanical structure is put forward, which shows using the designed flexure member can eliminated or attenuated the stress damage to optical element when the relative displacement of the components or the deformation caused by the temperature change. The parametric equation is established through analysis of the interrelation between the deformation of the different structure dimensions flexural member and the temperature change, and the parameters solving method is given too. Study on the installation method of the large size prism based on the kinematics and the semi dynamic and analysis of the influence of the optical properties of the prism under the difference installation structure on the prism,we present the calculation formula of the standard installation. Applying the above theory,the collimation focusing mechanism is designed.The overall scheme of star charts simulator, which is based on the optical coupling technology through the OLED combing with fiber and high-precision star target, is presented. Applying this scheme, the calibration system can achieve the high-precision calibration parameters including the star included angel, star brightness. This simulation technology having a wide range of magnitude value provides technical support for the further study on the deep space detection sensor.The lighting system of star charts simulator is detailed designed. Through research the coupling technology and analysis of the main effecting factors to the coupling efficiency, the scheme of the lighting system is presented. We choose the OLED as source, the polymer optical fiber and self-focusing lens to constructed the lighting system through comparison with several coupling methods and combing with the calculation results of energy loss of the optical system and the technical parameters of the coupling mechanism. The actual design and the simulation results show that the lighting system can provide5～10star brightness and realize the single star accurately controlled.Analysis of the key parameters of the calibration system mainly including the star included angle precision and the magnitude precision, we put forward theirs detection methods. The actual test results that star included angle accuracy<1",5～10magnitude simulation proves that the studied optical sensor calibration system meet the calibration precision of the current deep space navigation sensor.