SINS/CNS Integrated Navigation System Research

The SINS/CNS integrated navigation system gives priority to the strap-down inertial navigation system which complemented by the stellar stars azimuth information. The integrated system utilizes the information of the SINS and of the stars to improve aircraft navigation accuracy .The SINS can update the navigation parameter with a high speed but it also has the accumulated error due to the existence of the gyro drift error, in this case, the maladjustment angle increases with time . The other way round ,the CNS can not update the navigation parameter with a high speed but it has no accumulated error .So ,the two navigation system will be integrated .It uses the stars as a fixed reference point sources of information ,and use the star vector to observe the sensitive position of the fixed stars to correct the increasing drift error with time of the strap-down navigation system .The two navigation system give full play to their respective advantages ,and finally compose a integrated navigation system with eximious performance.This paper makes the research of the SINS / CNS Integrated Navigation System according to the SINS deficiencies, mainly on the following aspects:Firstly, this paper does the research on quaternion theory and coordinate system theory of the attitude solution, and deduces the quaternion coordinate transformation formula and build the basis for the attitude solutions. It also analyses the strap-down inertial navigation system role principle and its error propagation. And this paper also analyses the celestial navigation in the basic tenets and makes the research of the astronomical navigation system.Next, this paper deduces the TRIAD,q-method and QUEST-method theoretically, which are based on the observation vector algorithm of the star sensor for determining the attitude. And also compares these methods above with the indicators of the Wahba loss function by the simulation under the fixed direction cosine matrix,Stellar Vector and observation of Vector with Noise.Finally, this paper studies SINS / CNS principles and their compounding models. This paper also analyses the integrated navigation system error state using kalman filtering and deduces a new measurement equation. At the end of the paper ,gives the simulation curves .