Quick accurate alignment method based on fuzzy mapping earth spin velocity

Abstract

The invention aims to provide a quick accurate alignment method based on a fuzzy mapping earth spin velocity. The method comprises the following steps of: determining an initial position parameter of a carrier; acquiring outputs of a speedometer and a gyroscope; determining a rough initial attitude matrix; performing Kallman filtering single-step iteration computation according to a computed earth spin velocity; determining accurate alignment time; judging whether accurate alignment is over; if so, adopting a misalignment angle estimated with a Kallman filtering technology and correcting a strapdown attitude matrix of a system by using the misalignment angle to finish accurate initial alignment; and otherwise, returning to correction until accurate alignment is over, adopting the misalignment angle estimated with the Kallman filtering technology and correcting a strapdown attitude matrix of the system by using a misalignment angle to finish accurate initial alignment. In the method, any external observation equipment does not need to be arranged, and an auxiliary position rotary table does not need to be provided, the engineering is easy to realize, and the rapidness of the accurate alignment of a strapdown inertial navigation system is effectively enhanced.

Description

technical field [0001] The invention relates to an alignment method in the navigation field, in particular to a method for determining the initial attitude of a strapdown inertial system. Background technique [0002] The basic principle of the Strapdown Inertial Navigation System (SINS for short) is to use the accelerometer and gyroscope to measure the linear motion and angular motion parameters of the carrier inertial space according to the mechanical law of the relative inertial space proposed by Newton. Under the initial conditions of motion, the computer performs integral calculations to provide position, speed and attitude information continuously and in real time. According to the basic principle of SINS, SINS must obtain initial information, including initial position, velocity and attitude, before calculating navigation and positioning. The initial position and velocity information of SINS is easier to obtain than the initial attitude, and the accuracy of initial a...

AI Technical Summary

Problems solved by technology

Such as patent number: ZL200510130615.7 invention patent: a strapdown inertial navigation system arbitrary two-position initial alignment method; such as patent number: ZL200810064146.7 invention patent: filter-based fiber optic gyro strapdown inertial navigation system two positions The initial alignment method; it is to use the position turntable to perform multi-position alignment during the alignment process to improve the observability and observability of the system. Although these methods no longer need the difficult-to-achieve precision position turntable, they still need to be placed on the position turntable. conducted, limiting engineering applications

Such as the patent number: 200810019357.9 invention patent: fast and precise alignment method of strapdown inertial navigation system; the observability of strapdown inertial navigation system is improved by adding magnetic sensors and inclination sensors, but the orientation sensors used in this method are generally Geomagnetic sensor, this kind of geomagnetic sensor is easy to receive external interference, especially when the carrier is a magnetic conductor, it is difficult for the geomagnetic sensor to work normally and it is difficult to use it in practice

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