| The ship-borne quantum communication encrypted communication system is a device that is installed on the deck of a ship,and it is one of the cores of my country’s national defense strategy for deep seas.In order to ensure high-quality ship-to-satellite communications,it is necessary to maintain high-precision and high-stability targeting of the communications system with satellite under harsh sea conditions and complex ship vibrations.However,the stable attitude ability of the quantum communication system itself is not enough to compensate for large swings.And it does not have the ability to isolate the low-frequency vibration of the ship carrier,so it cannot meet the application requirements of communication equipment.In this regard,this thesis has carried out research on the structural design and analysis of ship-borne vibration isolation-stabilization systems in response to the high-performance communication demand of quantum communication systems in complex sea conditions.Firstly,focusing on the high-performance vibration isolation and stabilization requirements of the shipborne quantum communication system,the key technical points of the vibration isolation and stabilization system are analyzed.And a parallel three-degree-of-freedom(three-DOF)stabilization system and a high-performance non-angular displacement low-frequency vibration isolation system combined in series are proposed.Secondly,under the strict constraints of the space size,the kinematics characteristics of the three-DOF parallel system are analyzed.and the dynamic parameter optimization method of the three-DOF parallel stabilization system is proposed.The influence law of length error which is the main error source on the stabilization system is explained and the main structural parameters of the stabilization system are optimized.Thirdly,according to the high-performance vibration isolation requirements of the quantum communication system,combined with its working characteristics,the parameter matching design of the passive vibration isolation system is completed with the key frequency vibration isolation performance as the goal.According to the problem of which the passive vibration isolation system cannot meet the demand of high performance low-frequency vibration isolation,an absolute speed feedback active vibration isolation system is proposed to suppress the amplitude of the resonance peak in the low frequency.A parallel non-angular displacement mechanism is proposed to suppress the angular displacement vibration caused by multiple vibration isolators in different coupled lines.Finally,the stability performance test of the stabilization system and the vibration isolation performance test of the vibration isolation system were carried out respectively.The test results show that the stability error of the three-DOF parallel stabilization system is controlled within0.6°.The vibration transmission rate of the passive vibration isolation system at a critical frequency of 20 Hz in all directions is below-20 dB;through active control,the amplitude of the resonance peak can be below-10 dB,which meets the design requirements.Furthermore,the sea joint test of the whole system has been completed,and the results show that: through the vibration isolation-stabilization system works,the quantum communication system can capture and track the optical quantum channel of the satellite for a long time,and realize high-quality encrypted communication. |
