To meet the miniaturization and lightweight requirements of inter-satellite laser communication, this study investigates the servo control system of a silicon-based optical phased array (OPA). Based on the far-field radiation model for beam steering of the silicon-based OPA, combined with thermo-optic phase modulation technology and time domain response, the transfer function of the silicon-based OPA is established. To address noise and disturbances encountered during actual tracking, a silicon-based OPA beam tracking method for satellite platform vibration is proposed. The control algorithm employs a Kalman filter-based Model Predictive Control (KF-MPC) strategy. The advantages of the designed control algorithm were verified through simulations and experiments. Step response simulation results show that compared with the traditional PID control algorithm, the proposed algorithm reduces overshoot by 15.1% and shortens the response time by 76.4%. Sinusoidal tracking simulation results indicate a 27.15% improvement in tracking accuracy over the traditional PID algorithm. Experimental results demonstrate that the tracking accuracy of the servo control system with the proposed algorithm is 155.45 μrad, while that using the PID algorithm is 210.97 μrad, representing a 26.31% improvement in tracking accuracy. This research provides a valuable reference for the application of silicon-based OPA in inter-satellite laser communication.

In order to improve the imaging quality of the vehicle photoelectric servo system, image motion compensation under the vehicle platform is studied. Based on the principle of image motion compensation, combined with coordinate system transformation and velocity vector decomposition, the angular velocity compensation formula of a fast mirror in dynamic scanning imaging of a vehicle photoelectric servo system is obtained. A discrete sliding mode control algorithm based on the Kalman filter is proposed. The proposed algorithm and the discrete sliding mode control algorithm are simulated and compared to verify the system control performance. The simulation results show that the designed algorithm improves control accuracy by 76.3%, reduces overshoot by 75%, and improves response time by 31.25% compared with the discrete sliding mode control algorithm. The experimental platform is built to verify the experimental results. The experimental results show that the speed stability accuracy of the fast mirror is better than 19 μrad, which is 74.37% higher than that of the traditional control scheme. This study provides a reference for the follow-up study of image motion compensation in a vehicle photoelectric servo system.

To address the challenge of directly applying space laser communication systems to dynamic underwater environments, this paper integrates coordinate transformation matrices with underwater positioning systems, proposing an ultra-short baseline (USBL) system combined with a coordinate transformation-based underwater positioning model. The model is designed to effectively compensate for underwater dynamic disturbances, enhance the pointing accuracy of the system, and achieve stable tracking between underwater platforms. Simulation results demonstrate that the proposed model can enhance system tracking accuracy to 130.31 μrad (an improvement of 32.24%). Through underwater experiments, the results demonstrate that the underwater positioning model enables the system to achieve a pointing accuracy of 2.82 mrad (an improvement of 39.87%) and a tracking accuracy of 181.70 μrad (an improvement of 31.46%). Additionally, it can achieve underwater communication at 50 m with a data rate of 10 Mbps, providing a reference for future research on dynamic underwater laser communication.