Researches On The Strapdown Inertial Navigation System Algorithms In The Frequency And Wavelet Domain

The strapdown inertial navigation system (SINS) is mainstream technology of the inertial navigation today. The navigation algorithms in the software platform of the SINS are the key factors which affect the accuracy of the SINS greatly. With the development of the DSP processors and on the demanding of the modern navigation systems, redeveloping the inertial navigation algorithms in transform domain has been an important approach of the modern navigation research. In this thesis, related algorithms in transform domain are studied based on the idea of digital signal processing.First of all, based on the analysis of the signal reconstruction methods in the frequency domain, a signal reconstruction formula is obtained and a set of SINS algorithm is given in the frequency domain. We realize the frequency domain algorithms in the Matlab environment and do the simulation and analysis for the algorithms. The simulation results show that the SINS algorithms in the frequency domain can migrate the non-communicative errors during body movement and enhance the performance of the SINS effectively.Then, the laser gyro mechanical dithering is studied. We filter the dithering noise and compute the navigation parameters by utilizing the frequency domain SINS algorithms. The results show that the SINS algorithms in the frequency domain have a good effect on the filtering and navigation if the motion frequency and the noise frequency can be well separated out from each other.According to the way we develop the frequency domain SINS algorithms, a signal reconstruction formula in the wavelet domain is introduced and the signal reconstruction accuracy is analyzed. We develop the SINS algorithms in the wavelet domain according to the wavelet domain formula for signal reconstruction. On the basis of that, the characteristics of the wavelet domain SINS algorithms are summarized and the further research is proposed.