The Research On Line-Of-Sight Compensation Technology For Payload On Geostationary Orbit

With the development of geostationary meteorological satellite technology towards high time resolution, high spatial resolution and high spectral resolution, three-axis stabilized satellite platform has gradually replaced the spin-stabilized satellite and become the main choice of geostationary meteorological satellite in the future. Three-axis stabilized satellite has an obvious advantage compared to spin-stabilized satellite, but the attitude of the platform is difficult to keep steady by its nature. In order to obtain the high quality remote-sensing image, it needs not only that the satellite platform has high pointing accuracy and high stability of the attitude control system, but also the ability to carry on more strict INR(Image Navigation and Registration) work.One of the key problems to be solved in the INR system is to eliminate or reduce the effect of interference factors on the Line-of-Sight of the payload, ensuring the accuracy of the pointing of the Line-of-Sight. INR system has many compensation scheme, one of which is to use the high-bandwidth scanning mirror servo system. Based on the Line-of-Sight compensation requirement of the payload of FY-4 meteorological satellite, This paper will focus on the implementation of the compensation system----high-bandwidth high-precision scanning mirror control system, and carry out the related research work.This paper first analyzed the Line-of-Sight compensation requirement of the three-axis stabilized satellite. The requirement of the servo compensation system was got through the analysis of the characteristics of the amount of compensation. Furthermore, this paper completed the selection of the motor, the angular position sensor and other key components of the servo compensation system under the guidance of this requirement. In addition, the paper initially identified the structure of the servo control system.There have been a lot of research for the analysis of the performance of servo system. However, most of the theoretical studies nowadays are focusing on the continuous offline model, which has a distance away from the practical digital control system and are not able to establish an accurate correspondence between the model and the actual system. Aiming at this problem, this paper put forward the "continuous-discrete” hybrid model of Permanent Magnet Synchronous Motor(PMSM) servo control system based on the previous work, and used the hybrid model to analysis the bandwidth, stability, anti-interference ability of the system in detail. Besides, this paper establish the the real-time online model based on the semi-physical simulation technology, completed the verification of consistency of the whole link from the offline model to the actual system design, greatly simplifying the design process of the system, reducing the design difficulty, and make it real for the offline model to characterize of the actual system.Finally, on the basis of theoretical analysis, this paper completed the design of Line-of-Sight compensation system based on the semi-physical simulation technology, and completed the relevant experiments and Line-of-Sight compensation servo control system model in the system. The experimental results show the validity of the system scheme and the consistency of the offline model and actual system. Line-of-Sight compensation experiment results show the ability to track the compensation instruction of scanning mirror and the effectiveness of compensation scheme.