To Research On The Transfer Alignment Problems Of Inertial Navigation Systems

Considering the requirements of the initial alignment technology of the carrier aircraft inertial navigation system (CAINS), and aiming at the characteristic of the at-sea alignment for CAINS it develops the fast transfer alignment nonlinear error models which can be suitable for the large initial misalignment angles to research the fast transfer alignment technology of CAINS. Based on the Bayesian optimal estimation theory and Sigma-Points deterministic sampling numerical approximation methods it researches the new-type Sigma-Points filtering algorithms and applies these algorithms to study the filtering problems of transfer alignment error models instead of the traditional Kalman filtering algorithms and furthermore some key implementation problems of the fast transfer alignment algorithms implementation have been intensively studied.Based on the analysis of Gauss-Hermite quadrature approximation method of the Bayesian optimal estimation theory and its algorithm implementation, it comparatively studies the structure relation between Unscented Transformation filtering algorithm, center divided difference Kalman filtering algorithm and GHF algorithm of Sigma-Points filtering algorithms in modern nonlinear filtering theory. According to the analysis of the second order Stirling polynomial interpolation formula, it develops the second order Stirling polynomial interpolation filtering algorithm. Comparison with UKF algorithm implement and with Sigma-Points proper selected it develops the central divided difference filtering algorithm (CDKF) and furthermore discusses its extended form with additive noise (ACDKF) and square root (SRCDKF) as the same as UKF algorithm. From the statistical linearization idea, it discusses the Weighted statistical linear regression (WLSR) which being implicit in Sigma-Points filtering algorithms, and furthermore, it analysizes the posterior estimation precision of estimated mean and error covariance in SPKF algorithms. Simply expounding the INS basic theory and its output information computation methods, it analysizes their output information transformation relationship between Strap-down INS and platform-based. Based on the PWCS observability theory and methods, and according to the matrix spectrum condition numbers and perturbation theory it applies the spectrum condition numbers observability and observability degree analysis method to traditional linear fast transfer alignment model. It provides rational basis of maneuvering program for alignment process choice, and decreasing the alignment time and improving the alignment precision.Based on higher order Cayley transformation theory it discusses in detailed quaternion theory, Rodrigues Parameters, and modified Rodrigues Parameters theory representing carrier attitude, and their unity relationships, which provides the theory basis for the weighted mean calculation of quaternion and indirect calculation method for modified Rodrigues parameters'weighted mean, at the same time, it provides a new research way for attitude representation methods. Based on multiplicative quaternion method, it develops the improved multiplicative quaternion nonlinear error model of fast transfer alignment of CAINS; based on the relationship between quaternion error and multiplicative update of quaternion, develops the improved additive quaternion nonlinear error model for fast transfer alignment of CAINS; based on the analysis of modified Rodrigues Parameters in detailed develops its nonlinear error model for fast transfer alignment of CAINS. These three type velocity and attitude matching transfer alignment algorithms open up the new research direction for fast transfer alignment technology.Based on the characteristic of CAINS as-sea alignment it discusses the influences that Master INS in carrier ship may has some initial attitude error, on transfer alignment performance of CAINS and its conduction methods. It discusses the influence of the lever-arm effect error in transfer alignment system and with the lever-arm velocity error calculation compensation method researches the velocity error compensation of transfer alignment system for the lever-arm effect error. In the at-sea alignment of CAINS it Applies the ACDKF algorithm and SRCDKF algorithm to study the above three type velocity and attitude matching models, it simulated studies the effects of lever-arm effect error, the initial attitude error and the velocity error of master INS in carrier ship to the alignment performance of CAINS, and the influence of swing amplitude of carrier ship on the estimation performance of the above three type transfer alignment error models'state variables. The simulation results test these algorithms'availability, and the results provide the theoretical basis for properly selecting alignment model and filtering algorithm. Corresponding to various alignment models it provides the reasonable basis for whether to compensate for the lever-arm error and how to choose the IMU components. Moreover, the simulation results indicate that, in at-sea alignment of CAINS, the multiplicative quaternion error model and additive quaternion error model can fast estimate the azimuth misalignment angle, and reach at the same convergent performance as the two horizontal misalignment angles, and comparatively, the rapidity of convergence of the Modified Rodrigues Parameters error model is faster than other two models of quaternion, which is beyond other alignment algorithms.