Spacecraft attitude measurement method based on MEMS (micro-electromechanical systems) sensor

Abstract

The invention discloses a spacecraft attitude measurement method based on an MEMS (micro-electromechanical systems) sensor. The method comprises the following steps of: system initial alignment; signal acquisition; gyroscope attitude updating; real-time attitude calculation of a double-antenna GPS (global positioning system) / magnetometer; kalman filtering; and output correction. By selecting the combination mode of a three-axis MEMS gyroscope, a three-axis MEMS magnetometer and a double-antenna GPS, the spacecraft attitude measurement method provided by the invention has high measurement accuracy and reliability in comparison with other combination manners based on the microgravity and good GPS signal receiving effect of the spacecraft orbit space. According to the invention, a combined attitude measurement algorithm is also designed; finite rotation non-communicative errors are compensated by adopting an optimized three-sample rotation vector algorithm with the smallest error; and a simple and effective kalman filter state space model is constructed for the system to fuse the attitude information of two independent sources, thereby realizing complementary advantages of the gyroscope and the double-antenna GPS, and improving the dynamic reliability and accuracy of the system.

Description

technical field [0001] The invention relates to a method for measuring the attitude of a spacecraft based on a MEMS sensor, and belongs to the technical fields of attitude measurement and aerospace measurement and control. Background technique [0002] The attitude information of the spacecraft is one of the most important parameters of the spacecraft, and the real-time measurement of the attitude of the spacecraft is the key to realize the precise control of the attitude of the spacecraft. The attitude information of the spacecraft includes three attitude angles, namely pitch angle θ, roll angle γ and yaw angle ψ. The development of modern micro-spacecraft (or spacecraft subsidiary bodies) puts forward higher requirements for the reliability, accuracy, volume, weight and cost of the attitude measurement system. [0003] Searching through the search database of the National Patent Office, at present, the patents on attitude measurement are mainly "micro-small dynamic carrie...

AI Technical Summary

Problems solved by technology

The main disadvantages of this system are: (1) When the spacecraft is in a microgravity or weightless environment, the accelerometer cannot measure the acceleration of gravity or cannot distinguish it because the value of the acceleration of gravity is too small, and its output signal is mainly the carrier overload acceleration. The measurement equations are established incorrectly

(2) In a dynamic situation, the inertial device cannot distinguish the acceleration of gravity and the acceleration of overload, resulting in a large measurement error of the system

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