| In recent years, with the development of the geomagnetic measurement technology and geomagnetic matching navigation theory, inertial/geomagnetic integrated navigation has become the focus of research at home and abroad. The error of inertial navigation system is cumulative with time which cannot meet the high precision navigation requirement, but the geomagnetic navigation with a long-term, independent, high precision, all-weather advantages, so the inertial/ geomagnetic integrated navigation system can meet high precision navigation task requirement availably, which can be used as important means and beneficial supplement of modern navigation technology.Inertial/geomagnetic integrated navigation technology mainly includes denoising technology of the geomagnetic measurement data, the continuation technology of geomagnetic field, geomagnetic map suitability analysis, geomagnetic matching algorithm and inertial/geomagnetic integrated navigation algorithm. In view of the above hotspot questions, the following is the main work and innovations:(1) The denoising question of regional geomagnetic measurement data is studied. Using the wavelet technology and singular entropy technology based on the singular value decomposition theory are carried out on this question respectively, and then the validity of two kinds of technology are performed by simulated data and the actual measured data, the results show that both of the two technologies can denoising effectively about geomagnetic data. In addition, the denoising result by wavelet technology is better than singular entropy technology, but requires prior knowledge of wavelet basis and decomposition layers leading not easy to use. On the contrary, the technology of singular entropy is simple and the implementation complexity is low.(2) Continuation efficiency question about downward continuation of the geomagnetic field is studied. At present lots of fruits about downward continuation problem has been done, but the research fruits are not enough for continuation efficiency, so accelerated Landweber iteration method is proposed to solve the efficiency question of downward continuation on the basis of the Landweber iteration method. The frequency domain operators of two iteration methods are deduced and the filtering characteristics of operators are discussed, and find that two operators can suppress the high frequency noise. The experimental results of the simulation data and measurement data show that the accelerated Landweber iteration method cannot only deal with downward continuation of the geomagnetic field, but also more efficient than Landweber iteration method.(3) Suitability analysis of geomagnetic map is studied from the point of view of quantitative. In view of the disadvantage of one-sided evaluation when using a single index to evaluate geomagnetic map suitability, a comprehensive evaluation method based on multi-index fusion is proposed. The multi-index such as standard deviation, roughness, correlation coefficient, entropy and cumulative gradient is considered. To overcome the poor objectively of analytic hierarchy process (AHP) method when confirming the weight of the index, the comprehensive evaluation value is given by using entropy technology to amend the weight. The simulation by matching algorithm of MSD and MAD shows that the proposed method can evaluate the suitability comprehensively and reasonably. Bigger evaluation value can get higher matching probability, which indicates the good consistency between them.(4) Geomagnetic matching question is studied from the perspective of intelligent searching. The intelligent searching algorithm, which is suitable for geomagnetic matching after revised on the basis of the artificial fish swarm searching algorithm, is proposed for seeking out the optimal solution i.e. optimal result of the geomagnetic matching. The algorithm imitates the fish behaviors such as the preying, swarming, and following etc to achieve the global optimum value. Experimental results show that the proposed algorithm is effective and feasible from the perspective of searching optimization, and the repetition of experiments shows the reliability of the method in subsequent research.(5) A series of research and improvement methods for inertial/geomagnetic integrated navigation system is studied. From the point of view of tightly integrated, an extended Kalman filtering (EKF) algorithm was used to fuse the INS data and measurement data so as to ensure the filtering precision and stability by linearizing the geomagnetic anomaly surface with stochastic linearization method; In view of the measurement values contain outliers sometimes and the statistical properties of noise varies from time to time, a method based on innovation orthogonality adaptive Kalman filter is proposed to assure stability of filtering. From the point of view of loosely integrated, the filtering is performed based on geomagnetic matching algorithm. Experimental results demonstrate that the method not only has excellent performance, but also can overcome the large initial error.
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