Data blending method of navigation system combined by SINS/GPS micromagnetic compass

Abstract

The invention relates to SINS / GPS magnetic compass integrated navigation system data fusion method. It includes the following steps: processing position speed error combination for the SINS and GPS; estimating carrier position, speed, and altitude error by the first Kalman filtering to feed back and rectify SINS; calculating direction cosine matrix from carrier coordinate system to level coordinate system by outputted roll angle and pitch angle to assist magnetic compass to gain carrier magnetic course angle, and course angle; processing course angle error combination for the SINS and magnetic compass; estimating carrier altitude error by the second Kalman filtering to feed back and rectify SINS; outputting carrier position, speed, and altitude information from SINS to user. The invention has the advantages of simple computing, high precision, strong fault tolerant ability and wide application. Thus it can be used to increase magnetic compass altitude fixing precision, navigation precision of the SINS / GPS magnetic compass integrated navigation system used in space craft, aircraft, shipping, or surface car.

Description

technical field [0001] The invention relates to a data fusion method of a SINS / GPS / magnetic compass integrated navigation system. The method has the advantages of simple calculation, high precision, strong fault tolerance and wide application fields, and can be used to improve the performance of aircraft, spacecraft, ships or ground Navigation accuracy of SINS / GPS / magnetic compass integrated navigation system for vehicles. Background technique [0002] Strapdown Inertial Navigation System (SINS) is a completely autonomous navigation system that can continuously and real-time provide position, velocity and attitude (roll angle, pitch angle and heading angle) information, and its short-term accuracy It is very high, and has the advantages of good concealment and not limited by climatic conditions, so it is widely used in aviation, aerospace, navigation and other fields. However, the SINS error increases with time, so it is often combined with the Global Positioning System (GP...

AI Technical Summary

Problems solved by technology

At present, there are two commonly used methods for data fusion of SINS / GPS / magnetic compass integrated navigation system, one is to directly use the magnetic field strength error (obtained by comparing the measured value of the magnetic compass with the known vector value in the reference system) as the quantity Combining measured information with SINS and GPS, this method improves the accuracy of the heading angle of the system (it is often used in the aerospace field); but this combined estimation method must be based on the premise of knowing the trajectory information and the geomagnetic field model at that time. more complex

The other is to use the heading angle error (the difference between the heading angle calculated by the magnetic compass and the heading angle obtained by SINS) as the measurement information to combine with SINS and GPS to suppress the divergence of the heading angle error of the system. Many); but the heading angle must be obtained by using the geomagnetic field strength output by the magnetic compass on the premise of knowing the roll angle and pitch angle. If there is a large error in the roll angle and pitch angle, it will directly affect the accuracy of the magnetic compass to calculate the heading angle. At present, the east and north accelerometer information is used to calculate the roll angle and pitch angle, thereby assisting the magnetic compass to calculate the heading angle, but this method is only suitable for the case where the carrier is in non-accelerated motion. When the carrier is in accelerated motion, the heading Angular accuracy will be poor

[0004] All in all, the current data fusion method of SINS / GPS / magnetic compass integrated navigation system has the disadvantages of large amount of calculation, poor accuracy, narrow application range, etc., and it is difficult to meet the high-precision navigation requirements of spacecraft, aircraft, ships or ground vehicles

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