Polarized-Light/Geomagnetism/GPS/SINS Integrated Navigation Algorithm
|School||Harbin Institute of Technology|
|Course||Navigation,Guidance and Control|
|Keywords||integrated navigation federated Kalman filtering polarized-light geomagnetism fault-tolerance|
High accuracy, high credibility and low cost are the basic requirements of integrated navigation system. It is the key technique that how to fuse many navigation systems and design the high-accuracy, robust integrated navigation system. Based on the research of modern navigation performance and information fusion theory, a polarized-light/geomagnetism/GPS/SINS integrated navigation algorithm is designed, with a navigation system which is applicable to high-altitude unmanned reconnaissance aircrafts as background.Usually, sensors utilized in the navigation systems have different sampling rates. Hence, a novel data fusion strategy in the federated Kalman filtering is proposed to tailor the algorithm to the multirate sampling systems. And the methods of“Local State Expansion”and“Local State Truncation”are given, because the dimensions of subsystem vectors are different. The numerical simulations are given that use the filtering arithmetic.To increase the attitude errors observation performance of GPS/SINS integrated navigation system, the polarized-light and geomagnetism aided navigation methods are proposed. The principles of the polarized-light aided attitude determination approaches are described, and the equations of the polarized- light measurement models of attitude errors are developed. An integrated scheme of the polarized-light/geomagnetism/GPS/SINS integrated navigation is given, and the performance of this new scheme is compared with that of the GPS/SINS integrated system. The results indicate that our scheme has a stable capability of attitude error correction.In order to improve the fault-tolerance of the polarized-light /geomagnetism/GPS/SINS integrated navigation system, the theory of fault-tolerant design for integrated navigation systems is studied in the last part of this dissertation.χ2-detection method for validity of local filters measurement data is mainly studied. When outliers exist in measurement, a fault diagnosis scheme is studied. Based on Residual-χ2-detection method, a fault-detection-isolation-reconstruction algorithm for local filters is designed in this polarized-light/geomagnetism/GPS/SINS integrated navigation system. The simulation results show that it will restrain wrong alarm well which caused by outliers, and the fault-tolerance of the integrated navigation system is improved.