| With the continuous progress of photoelectric technology and the development of astronomical navigation,in order to provide high-quality and efficient integrated navigation system,astronomical navigation is often used as a subsystem of integrated navigation for data fusion,and then more accurate navigation information can be solved.Strapdown navigation has high positioning accuracy in a short time,but it will accumulate errors in a long time because of its gyro drift and acceleration bias.Astronomical navigation and positioning is stable but the accuracy is slightly lower.The combination of the two can overcome their respective defects.However,in the actual algorithm verification process,attitude information cannot be acquired through the launching carrier every time,and the cost is too expensive.Paper based on the national natural science fund and innovative talents of science and technology research fund in Harbin,to carry out the Strapdown Inertial Navigation System(Strapdown Inertial Navigation System,SINS)/Celestial Navigation System(Celestial Navigation System,CNS)integrated Navigation simulation and the simulation platform of star sensor map quickly identify the map algorithm research,SINS/CNS in the laboratory simulation platform for testing and validation.The SINS/CNS simulation platform was used to test and verify the system,which included the simulated trajectory part,the simulated star map part,the star map processing part,the inertial navigation attitude solution part and the astronomical navigation attitude solution part.The simulation star map,the star list construction algorithm and the fast matching algorithm of the star map were also studied.The main work contents of this paper are as follows:1)Aiming at the problems of redundant matching results and numerical extremity caused by the traditional construction method of star catalogue,a new method of star catalogue construction based on triangle division is proposed based on the traditional triangle construction method.The catalogues are divided into 5000 subblocks according to longitude,which reduces the scope of navigation catalogues in a single traversal.Through three-dimensional triangle division,the number of angular distances stored by stars in the whole day region is greatly reduced,and the angular distance string is constructed to optimize the storage data.The improved catalogues can match the navigational stars only through one traversal of the catalogues,which greatly reduces the matching redundancy and matching time.Compared with the traditional catalogues,the stored values of the improved catalogues are approximately normal distribution,the data differentiation is large,and the single matching redundancy is low.2)Aiming at the problems of slow speed and low efficiency of traditional star map matching algorithm,a fast star map recognition algorithm based on triangulation was proposed on the basis of traditional triangle matching algorithm.In order to improve the speed and efficiency of single star map recognition,the star information is stored according to the star list,the angular distance string is constructed,and the navigation star list is retrieved.Furthermore,the tracking mode of star map recognition algorithm is improved to ensure the real-time performance of the algorithm.Finally,the influence of the number of partitions and the interference stars on the improved algorithm and the traditional algorithm is verified.Compared with traditional star map matching algorithm,the improved triangulation algorithm has better robustness and timeliness in the process of static star map matching.3)The traditional algorithm and the improved algorithm were tested and verified on the SINS/CNS integrated navigation simulation platform.Relevant parameters of the platform were calibrated,and the trajectory was simulated by Qt software programming.The trajectory data of any launch site and any initial attitude were obtained,and the dynamic simulated star map with 8°×8° field of view and 500×500 size was generated according to the data.Star simulator is used to simulate space environment,and industrial camera replaces star sensor to capture dynamic star map.Finally,the timeliness and accuracy of the traditional star map recognition algorithm and the improved star map recognition algorithm are verified in the star point recognition mode and tracking mode respectively.Simulation results show that the overall timeliness of the improved algorithm is better than that of the traditional algorithm. |
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