Airborne distribution type POS (position and orientation system) transfer alignment method based on parameter identification

Abstract

The invention discloses an airborne distribution type POS (position and orientation system) transfer alignment method based on parameter identification. An airborne distribution type POS comprises a high-precision master POS and a plurality of sub IMUs (inertial measurement units). Aiming at the problems of unknown elastic deformation and time change of a machine body, the elastic deformation angle of the machine body is regarded as a second-order Markoff process, the elastic deformation angle and the elastic deformation angle speed are expanded into state variables, the differences between the speeds and the postures of the master POS and the sub IMUs are measured, and a mathematic model of sub IMU transfer alignment is built; then, the Kalman filtering is performed and parameters of the second-order Markoff process are calculated and updated by virtue of the estimated elastic deformation angle and elastic deformation angle speed; at last, the updated second-order Markoff process parameters serve as initial filtering values at next moment to estimate the relatively accurate posture errors, speed errors and position errors of the sub IMUs, strapdown calculation results of the sub IMUs are corrected by virtue of the errors, and the relatively accurate positions, speeds and postures of the sub IMUs are calculated.

Description

technical field [0001] The invention relates to an airborne distributed POS transfer alignment method based on parameter identification, which can be used in various strapdown inertial navigation systems that need to determine the position, speed and attitude through transfer alignment technology, and is especially suitable for the elastic deformation of the body Case. Background technique [0002] Multi-task remote sensing payload is one of the current development directions of airborne earth observation, such as integrating high-resolution mapping camera, imaging spectrometer, large field of view infrared scanner, synthetic aperture radar (Synthetic Aperture Radar, SAR) Task load, airborne distributed array antenna SAR and flexible multi-baseline interferometric SAR, etc. For a high-performance aerial remote sensing system equipped with mission remote sensing loads, it is necessary to achieve high-precision measurement of the motion parameters of each load distribution po...

AI Technical Summary

Problems solved by technology

However, the problem with this method is that the selection of the above parameters is mostly determined by experience, and it is difficult to guarantee the accuracy of the parameters in practical engineering applications.

In addition, the Markov process parameters of the elastic deformation angle of the aircraft will change with external factors during the flight process. Even if the corresponding process parameters can be given based on experience at the beginning of the filtering, it cannot guarantee that the system state model and noise statistical characteristics will The accuracy in the filtering process, the filtering accuracy will decrease or even diverge

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