Real-time star image coordinate extraction method of star sensor with multi-output image sensor

Abstract

The invention provides a real-time star image mass center extraction method of a star sensor with a multi-output image sensor. The method comprises the following steps: judging whether a fixed star image exists on an edge of a component image in the process of extracting fixed star image coordinates, and directly calculating the corresponding star image coordinates by a gravity center method if the fixed star image does not exist on the edge of the component image, or if the fixed star image exists on the edge of the component image, saving a gray value of the fixed star image in the fixed star image coordinate extraction process, and saving edge information of the fixed star image; and finally, judging all pixels of which fixed star images are distributed in two component maps according to the edge information, and calculating the corresponding fixed star image coordinates of the fixed star images of which the pixels are distributed in the two component maps by the gravity center method. The method has a high real-time property, the data updating rate of the star sensor is improved, and the dynamic property of the star sensor is further improved.

Description

Technical field [0001] The invention relates to a method for real-time extraction of star image coordinates by a star sensor of a multi-output image sensor. Background technique [0002] The Star Sensor is a high-precision and high-reliability attitude measurement component widely used in various aircraft. Its working principle is: the star light emitted by the star is imaged on the image sensor through the optical system. The image sensor converts the light signal into an electrical signal and forms a complete digital star map. The data processing unit processes the digital star map. The extraction software performs large target elimination, star image coordinate extraction and star magnitude calculation on the star map. The star recognition process constructs a matching pattern for the stars in the star map according to the matching method, matches and processes the existing patterns in the navigation star database, and forms a unique matching star pair between the observation...

AI Technical Summary

Problems solved by technology

The implementation of star image coordinate extraction algorithm includes a large number of operations, which are addition and subtraction operations, and the algorithm control structure is relatively simple, which is suitable for FPGA implementation. Therefore, FPGA can be used to extract star image coordinates from multiple channels in parallel. When all the pixels of the star image are distributed in two sub-images, the traditional real-time extraction method can only extract the corresponding coordinates from each sub-image, which causes the pixels of the star image to be "divided" into two parts, resulting in the extraction The star image coordinates of the star image are incorrect, and because the star sensor is aligned with the celestial sphere immediately during use, there may be multiple star images in the star map. All pixels are distributed in the two sub-star images. In order to avoid the The problem caused is that the user has to save the image to the memory first, and then read the star map data from the memory to extract the coordinates of the stars in the star map, which results in a time difference between reading the image from the sensor and extracting the stars. The serial work of the star image coordinate time increases the update cycle of the star sensor, reduces the real-time performance of extracting star image coordinates, and thus reduces the data update rate of the star sensor

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