Optimized Design Of Satellitelaser Communication Coarse Pointing Control System

With the development of science and technology, the satellite is the important carrier of space to ground communication, and the quality of the communication is higher and higher. Compared to the traditional microwave communication, satellite laser communication as a new means of communication, with the advantages of high frequency, short wavelength, good point, relatively independent of the band and confidentiality good, so satellite laser communication since the day of birth showed the vigorous vitality, has become the hot research. In sate llite laser communication system, in order to maintain a good communication link, we must establish acquisition, pointing and tracking(APT, acquisition, pointing and tracking) system, the coarse pointing control subsystem is an important part of the APT system. In this paper, the Harbin Industrial University bear the "between relay satellites link technology" subject as the background, the coarse pointing control system sub part of in-depth study and optimization, put forward the hypothesis and the corresponding simulation and experimental verification.Scan and capture as the key step of APT system. In the first part, the optical communication scanning capture process between satellites were analyzed and expounds the common scan acquisition mode, then thro ugh the model establishment and simulation optimization is proposed, including were used in single field scanning and uncertain field scanning condition optimization, combined with spiral and sinusoidal scanning, scanning scheme of the utility model is proposed, and for coarse pointing errors asymmetry is high when the scanning mode choice.Secondly, according to the coarse pointing feedback link analysis and feedback devices to measure the absolute photoelectric encoder are proposed improvement scheme of software redundancy; and the decoding unit in coarse code decoding circuit optimization, in order to adapt to such as rocket launcher caused by severe vibration dynamic caused by mechanical deformation or outer space high and low temperature and other factors caused by all kinds of errors caused by.Finally, the control algorithm of the coarse aiming control unit is optimized.. The issue of the use of incremental PID algorithm in practical work in the presence of pointed out that the then introduced with qui ck response, the parameter variation and disturbance is not sensitive, no need for online identification and modeling system, the sliding mode variable structure control, and a simulation analysis was carried out. The sliding mode controller of the incremental PID controller as a backup, in space in standby, in order to achieve the best coarse pointing control effect, for subsequent transfer to the fine pointing control system to maintain good communication link, to provide the necessary accuracy.