Off-line wavelet denoising fast initial alignment method

Abstract

The invention discloses an off-line wavelet denoising fast initial alignment method which has the advantages that the initial coarse alignment time of a high-precision strapdown inertial system is further reduced, and the accuracy is further improved. The method comprises the following steps of (1) acquiring sensor data comprising data of an optical fiber gyroscope and a quartz flexible accelerometer; (2) establishing initial alignment coordinate systems comprising an initial carrier coordinate system, an initial navigation coordinate system, an initial earth coordinate system, a carrier coordinate system, a navigation coordinate system, an earth coordinate system and an inertial coordinate system; (3) establishing a gravity apparent motion vector model, and constructing an off-line wavelet denoising algorithm; (4) utilizing a gravity apparent motion vector subjected to denoising and filtering for calculating an optimum initial attitude; (5) utilizing the calculated optimum initial attitude quaternion and using an attitude matrix chain rule to realize a fast initial alignment process. According to the off-line wavelet denoising fast initial alignment method provided by the invention, the calculation accuracy and the efficiency of an initial alignmentalgorithm are effectively improved, and the application range is wide.

Description

Technical field: [0001] The invention relates to an initial alignment method of an inertial measurement unit under the condition of a shaking base, and belongs to the technical field of strapdown inertial navigation. Background technique: [0002] The initial alignment technology is one of the key technologies of strapdown inertial navigation technology, and the improvement of alignment accuracy is conducive to the improvement of the calculation accuracy of strapdown inertial navigation. At present, the commonly used strapdown inertial navigation initial alignment technology is mainly divided into two processes: coarse alignment and fine alignment, and the alignment accuracy of fine alignment largely depends on coarse alignment. The alignment accuracy has high practical significance. Commonly used strapdown inertial coarse alignment methods include analytical coarse alignment, inertial system coarse alignment and solidification analytical coarse alignment. Among these three...

AI Technical Summary

Problems solved by technology

However, in the solidification analytical coarse alignment, the real-time analytical calculation of dual vectors is used. During the vector calculation process, it is easily affected by external interference and sensor measurement noise, which reduces the alignment speed and increases the alignment time, which is not conducive to the rapid initial alignment of the inertial system. Standard requirements

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