Research On Photoelectric Tracking Control System For Underwater Laser Communication

Underwater laser communication has the advantages of good confidentiality,large capacity and fast transmission speed.It can be widely used in places such as underwater submarine communication,underwater resource exploration and marine environmental monitoring,and it is very important in military and civilian fields.The rapid establishment of the underwater laser communication link and the continuous and stable maintenance are the basic conditions for the application of underwater laser communication.In the presence of platform disturbance and seawater random channel perturbation and other conditions,how to achieve high-precision,fast alignment is the must solve problem to achieve underwater optical communication.In this paper,the problem of communication failure caused by the interference of the external environment in the process of underwater laser communication is studied.Based on the characteristics of the photoelectric tracking system and the underwater laser communication technology,a set of underwater laser communication photoelectric tracking control system is designed.Firstly,the common target tracking algorithm applied to the electro-optical tracking system is studied.According to the problem of the continuous movement of the laser spot during the underwater laser communication,the tracking effect and application environment of the target tracking algorithm are simulated and analyzed.The target tracking program combined with the Mean Shift algorithm and the Kalman filter algorithm is designed and experimentally tested in the laboratory.Secondly,the whole structure of the underwater laser communication photoelectric tracking control system is designed.The motor control algorithm based on the four-quadrant tracking principle of the video image is studied for the servo control system.Based on the mathematical model of the motor,the corresponding ratio control equation for the proportion of the missing target is established and the motor control module of the host computer program is designed.Aiming at the influence of the underwater environment on the platform,the stability control module with MPU9250 as the inertial sensing unit is developed.The experimental results show that the system can be restored to the course by the stabilization control module and the pitch is 0° stable state.Then,according to the practical application background of the underwater laser communication photoelectric tracking control system,the PPM modulation principle of the laser signal is studied,the PPM modulated laser communication system is designed,and the underwater laser communication transmission effect of the text information is tested in the laboratory.Finally,the experimental system is designed to test the indoor target tracking performance and the underwater laser spot tracking performance of the electro-optical tracking control system in the laboratory.The communication effect of the underwater laser communication photoelectric tracking control system is experimented test.The experimental results show that the underwater laser communication photoelectric tracking control system can track the moving laser spot to realize the underwater laser communication function,which has certain engineering significance.