The Research And Design Of Initial Alignment In Strapdown Inertial Navigation System

In order to start INS calculate in the navigation mode the initial parameters of the transformation matrix C_bⁿ are needed. The determination of above parameters is called as an INS alignment. The alignment of strapdown system is similar to the local-level platform system. The difference is so, that in the strapdown system the platform is calculated while in the local-level one is physically realized. This paper was designed from the point of view of control to study SINS initial alignment, hammer at to get a better strapdown system initial alignment method.In this thesis, the general error model of the SINS is presented in detail. Begin with the study of error models and the analysis of observability, the author investigates the alignment problems, and designs software for simulation and actual application. All effectiveness of these studies is proved through simulation results using the software.In alignment mode, the following sequential procedures are realized: constitute of initial transformation matrix; coarse alignment; fine alignment. On the unmoving and swaying base, the initial alignments are studied respectively. More important, a new method of initial alignment was developed for the strapdown navigation system (SINS) by designing a dynamic controller using H₂ and H_∞ optimize control theorems. The thesis contributes to decrease system errors, increase the precision and reliability of alignment..