Research On Coarse Tracking Mechanism Of Light And Small Periscope Laser Communication Terminal

As a high-speed communication method,space laser communication technology has become a potential communication method with great development prospects to break the bottleneck of increasing microwave communication rate and realize high-speed transmission of satellite mass data.As an important part of the optical communication system,the laser communication coarse tracking and aiming mechanism is the prerequisite for successful inter-satellite communication.In this paper,aiming at the requirement of light and small size of space laser communication system,the design and key technology research of light and small Periscope laser communication terminal coarse tracking and aiming mechanism are carried out.Through consulting data,analyzing the influence of space environment constraints on the small satellite laser communication system,establishing the technical indexes of the laser communication system,comparing and analyzing the classical communication system structure forms,and finally determining that the laser communication coarse tracking and aiming mechanism designed in this paper is a Periscope type;From the aspects of establishing the overall structure,material selection,shafting establishment,light weight of parts,etc.,the detailed light and miniaturization design of the coarse tracking and aiming mechanism is carried out.Considering the influence of space thermodynamic environment on the system,the mirror surface shape optimization design of the mirror assembly is completed,and the frequency sweep experiment and mirror surface shape detection experiment of the mirror assembly are carried out.Analyzing the factors that affect the pointing accuracy of the Periscope laser communication system,establishing an error transmission link,completing the establishment of a beam transmission mathematical model,simulating the mathematical model with Matlab software,obtaining the relationship between the system pointing error and the shaking of the azimuth shafting and the shaking of the pitching shafting,establishing the error range of the shaking of the azimuth shafting and the shaking of the pitching shafting,and completing the detection of the actual shaking amount of the shafting;According to the locking/unlocking requirements of the coarse tracking and aiming mechanism,a locking mechanism based on shape memory alloy that can be locked/unlocked repeatedly is designed.The influence of the locking stiffness of the locking mechanism on the mode of the whole machine is analyzed,the unlocking force isoptimized,and the frequency sweep test experiment of the whole machine is completed.