Small satellite autonomous navigation system based on starlight/ geomagnetism integrated information and navigation method thereof

Abstract

The invention provides a small satellite autonomous navigation system based on starlight / geomagnetism integrated information and a navigation method thereof and belongs to the technical field of integrated navigation. The autonomous navigation system comprises a star sensor measuring system, an earth magnetic field measuring system, an orbit determination system and an attitude determination system. The navigation method comprises the following steps of: the establishment of a navigation system state equation, the measurement equation establishment of the navigation system and integrated navigation system information fusion based on UKF(unscented kalman filter). According to the method, a large view filed star sensor is utilized to simultaneously observe starlight vector information of multiple navigational stars, thereby making up the defect caused by overlarge measurement noise of a magnetometer and obtaining high navigation accuracy; based on track and attitude information contained in the measured values of a magnetometer and the star sensor and in comprehensive consideration of influences of various factors, a measurement equation of the system is established, the adaptability and the stability of a filter to measurement noise are improved; therefore, the method is suitable for navigation of a low earth rail small satellite adopting a cheap small autonomous navigation system.

Description

technical field [0001] The invention relates to a small satellite autonomous navigation scheme design system and a navigation method based on combined starlight / geomagnetism information, and belongs to the technical field of combined navigation. Background technique [0002] Satellite autonomous navigation means that the satellite can determine the position, velocity and attitude of the satellite in real time only by the measurement equipment on the satellite without relying on the ground station, and complete the functions or operations required by the flight mission in orbit. At present, satellites mainly rely on ground stations for tracking and orbit determination. However, due to the large number of satellites in the small satellite network, the use of ground equipment to locate the satellite network has the difficulty of short measurement arcs and many measurement targets. With the continuous increase of small satellites in low and medium orbits, traditional ground meas...

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Problems solved by technology

[0006] Aiming at the problems existing in the prior art, the present invention proposes a small satellite autonomous navigation system and its navigation method based on combined starlight / geomagnetism information, which solves the problem of excessive geomagnetic navigation error caused by the low measurement accuracy of the magnetometer , analyze the characteristics and limitations of geomagnetic navigation and astronomical navigation based on star sensors, make full use of the starlight vector information of multiple navigation stars provided by the large-field star sensor and the three-axis magnetometer to obtain the geomagnetic field information around the earth, The complementary advantages of the two are realized, and the information fusion is carried out through the UKF filtering method, which improves the reliability while improving the accuracy

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