Since FPGA processing data, the presence of fixed-point processing accuracy is not high, and IP Core floating point unit and there are some problems in the use of design risk. Based on the improved floating point unit and program optimization algorithm is designed to achieve single-precision floating-point add / subtract, multiply, and divide operations operator. IP Core for floating-point unit design and FPGA development software provides comparative results: both the maximum clock frequency and latency basically unchanged, while the former occupies less hardware resources, to complete a plus / minus, multiply, divide computation time required for the former than the latter were reduced by 46%, 37% and 57%. The program is downloaded to the FPGA chip to get the same results with the simulation results verify the correctness and feasibility of the design.

Dynamics characteristics of SINS damping system in shock environment were analyzed by finite element method, as the deformation of dampers may leads to the accuracy loss of SINS. In addition, the influence of absorber stiffness and damping coefficient on dynamics characteristics were studied. The results indicate that the decoupling of vibrations is significant for the accuracy of SINS. However, considering the almost impossible of completely decoupled vibrations, its necessary to carry out an optimal design of the absorber stiffness and damping coefficient to maintain the accuracy of SINS while meeting the requirement of vibration isolation.

Aimed at disturbance caused from motor running and personnel ambulation during initial alignment process of SINS, a new signal detection method of disturbance based on wavelet analysis is brought out. Through analyzing original signal characteristic of FOG and the data with wavelet filter on disturbance base, finds out wavelet filter just have effectiveness to high frequency noise. Then T&L signal detecting law is introduced, and builds T&L signal with high frequency part of wavelet decomposing to estimates interfere time and then resample. Offline simulation experiment results indicate the method can eliminate low frequency disturbance effectively and has certain apply value.

A wavelet method is introduced to compensate stochastic errors of FOG attitude measurement system, analysing and comparing threshold and threshold function principle, a new threshold function combining with soft and hard threshold was designed. Adopting data moving window realizes recursive computation and real-time data update and solves filtering signal’s boundary problem with symmetric periodic extension method, and achieves real-time wavelet threshold filter. Experimental results show the feasibility of the real time wavelet threshold method in FOG signal de-noising, the real-time wavelet de-noising algorithm with new threshold function has the advantages of single algorithm. which improves the precision and stability of the FOG.