Research On Acquisition And Coarse Tracking Control In Quantum Positioning System

Quantum positioning is a method of locating the ground,which uses quantum light as the carrier.The theory of quantum positioning is the system can obtain time difference between entangled photon pairs after data transmission and processing of entangled photon pairs between the quantum satellite and the ground end.Compared to traditional global positioning system,quantum positioning can get higher positioning accuracy and good confidentiality by making use of the entanglement characteristics of quantum light.However,different from traditional global positioning system,quantum positioning system has higher requirements for high precision alignment and maintaining link stability.Therefore,high-precision alignment and maintaining link stability are particularly important in the design of quantum positioning system.In this thesis,based on completing the hardware selection of the components of the signal transmission device in the quantum positioning system,a coarse tracking control system are designed to meet the coarse tracking performance index by making use of related technology of Acquisition,Tracking and Pointing(ATP)system acquisition and rough tracking in quantum positioning system.In addition,the entire control simulation process and results are integrated into the Graphical User Interface(GUI).The MATLAB GUI-based animation simulation demonstration platform is designed.The main research contents of this thesis are divided into following three parts:1.The composition and selection of the signal transmission device of the quantum positioning system and the acquisition and coarse tracking technology of the ATP system are studied in detail.The indicators of acquisition phase and the various techniques of coarse tracking phase are focused on analysis.Some suggestions on performance metrics and their influencing factors to improve acquisition performance are provided.2.The acquisition and coarse tracking system is designed and studied in detail.The expected signal of the coarse tracking control system is calculated by applying the mathematical knowledge of geometry and the theoretical knowledge of spatial coordinate transformation.The continuous and discrete models of the entire acquisition and coarse tracking system of the azimuth and pitch axes are established.Specifically,three closed-loop control strategies and acquisition algorithms are designed.The parameters in each closed loop are adjusted and optimized to meet the accuracy requirements of coarse tracking through system simulation experiments.For four different stages of the satellite passing through the ground(user)visible region,the simulations of azimuth axis and pitch axis of the two-dimensional turntable in acquisition phase and coarse tracking phase are implemented in Simulink environment,respectively.The simulation results verify that the designed control system can achieve the desired results.Moreover,based on the results,suggestions about acquisition are provided.3.The acquisition and coarse tracking part of the MATLAB GUI-based animation simulation demonstration platform is designed.The simulations of the ATP system acquisition and coarse tracking part are integrated under the conditions of six kinds of initial pointing errors and three kinds of starting acquisition moments.In addition,the 3D animation of the satellite on-orbit motion is simulated in the Satellite Tool Kit(STK)software,which is integrated into the MATLAB GUI-based animation simulation demonstration platform.