1 Subject
The disciplines of this project are flight control and navigation technology, and the related disciplines are image processing and machine vision, photoelectric detection and camera technology.
2 Project background
Star sensors use "precise" star attitude determination. They are currently the attitude sensors with the highest measurement accuracy in aerospace applications. They are the core products of various spacecraft represented by satellites.
Due to the gap between domestic star sensors and demand in terms of accuracy and dynamics, during the "Tenth Five-Year Plan" and "Eleventh Five-Year Plan" periods, domestic satellites mainly relied on imported star sensors, while domestic medium precision (510 ") star sensors are basically used as backup. Judging from the on-orbit situation, there are many problems with domestically produced star sensors, and most of them have not effectively completed their tasks. Judging from the needs of my country's 12th Five-Year Plan and subsequent satellites, most satellites have put forward requirements for higher indicators of measurement accuracy of 3 "and dynamic performance of more than 1°/s. At the same time, due to restrictions on the export of high-end foreign products, it is difficult to introduce high-precision and high-dynamic star sensors, which has become a bottleneck problem in my country's satellite development.
It is against this background that relevant national departments established the "CCD High-Precision and High-Dynamic Star Sensor" project during the "Eleventh Five-Year Plan" period, which was undertaken by the Shanghai Institute of Aerospace Control Technology. The project achieved its first flight on a satellite in November 2011, performed well, and has been operating stably in orbit so far.
3 Main content and technological innovation
This project has the advantages of high precision, good dynamics, light and small size, low power consumption, stable operation, etc., and has the following technical innovations:
(1) A 1024×1024 large area array CCD detector was used for the first time in domestic star sensors. A method for extracting the center of the spot is proposed that is anti-noise and halo, which solves the problem of dynamic star tailing, slow recognition speed and low accuracy of star point centroid positioning;(2) Propose a parallel processing technical scheme for image exposure, centroid positioning, star map recognition, and attitude solution. By adopting a three-level pipeline task scheduling mechanism, it solves the problem of low data update rate and star map recognition caused by traditional star sensor signal processing. Long time;(3) Proposed a star tracking algorithm based on attitude motion information and related prediction mechanisms, which solves the technical problems of high misrecognition rate, easy loss, and low accuracy of star points in wavelet gate tracking under dynamic conditions, and greatly improves the ability of star sensors to continuously and stably output high-precision effective attitude data;(4) In response to the needs of subsequent satellites for small size and low power consumption of star sensors, the noise and low-frequency error suppression difficulties caused by the integrated high-density optical-electromechanical design have been solved through the optimization of optical, mechanical, electrical and thermal design.
4 Patents, papers and comprehensive level
The project has formed 8 patents, including 3 authorizations, 6 monograph papers and 8 software registered copyrights.
The comprehensive technical level of this project ranks first in China and reaches international advanced, filling the gap in domestic CCD high-precision and high-dynamic star sensors. It is of great significance to breaking the situation of star sensors relying on imports and ensuring that this core product is independently controllable.
5 Promotion and application and economic and social benefits
The results of this project can be promoted and applied to other photoelectric sensors such as very high precision star sensors, navigation sensors, ultraviolet sensors, etc. Research in related fields will play a strong role in driving, such as high-precision observation of low-light targets, recognition and extraction of weak image signals, image matching technology, etc.
This project can be widely used in satellites such as meteorology, ocean, disaster reduction, navigation, and communications, greatly improving the measurement and positioning accuracy of satellites, and has significant implications for agriculture and forestry, ocean water conservancy, energy and minerals, surveying and mapping, and environmental protection, etc., related to national economy and people's livelihood. contribution.
According to incomplete statistics, during the "12th Five-Year Plan" and "13th Five-Year Plan" period, the demand for such high-precision and high-dynamic star sensors by various domestic spacecraft exceeded 260, and the economic scale reached 10.415.6 100 million yuan.