Study On Safety Control And Mission Planning For Multi-spacecraft Cooperative Proximity Operations

In recent years,major space countries or organizations at home and abroad have made great efforts to develop on-orbit service technologies centering on space proximity operations.It will be an important form of on-orbit service in the future to complete proximity operations by the cooperation of multiple spacecraft with the same or different functions.The corresponding design and planning of the mission is more complicated than traditional single-spacecraft-operation mode.In the background of multi-spacecraft cooperative operation,this paper mainly studies the design,safety control and collaborative planning of multi-spacecraft proximity observation missions and rendezvous missions.The main results achieved in this dissertation are summarized as follows.The design method of the proximity-fly-around observation mission of multiple spacecraft under multiple constraints has been studied.The spatial geometry,load performance,safety performance and other constraint models of the spacecraft three-dimensional detailed-survey mission are established.The coverage performance is analyzed by grid statistical method,and then the design and analysis of multi-spacecraft close-distance three-dimensional detailed-observation missions is carried out.The simulation results show that the design method is effective.The minimum time of observation mission decreases periodically as the fly-around distance increases.The full coverage effect can be achieved by using the strategy of rotating observation optical axis and the multi-spacecraft formation observation strategy.In terms of the real-time coverage rate and the shortest time of detailed inspection,the multi-spacecraft observation is more effective than the single-spacecraft observation.An algorithm for multi-spacecraft proximity collision-avoidance control under dynamic anti-collision zone constraints is presented.The existing anti-collision control method based on artificial potential function has been improved from three aspects: introducing instantaneous collision probability for collision warning,considering the speed safety approach corridor and accounting for the actual acceleration form.A real-time dynamic obstacle zone is established.And a dynamic anti-collision control algorithm for multiple spacecraft proximity safety is proposed.Based on group decision,the influence of the main parameters of the control algorithm is analyzed.Based on the genetic algorithm,the main influencing parameters of the control algorithm are optimized.The simulation results show that the safe maneuver trajectory obtained by the proposed method can reduce the task time,save the propellant consumption,and avoid the local minimum point problem caused by improper parameter selection of the anti-collision control algorithm.A hierarchical collaborative planning system for multi-spacecraft proximity missions is studied.The model of multi-spacecraft observation mission optimization is established considering the solar ray incident angle constraint and security constraint.Based on the hierarchical cooperative strategy of multi-agent system,a multi-spacecraft cooperative observation mission planning model is established.Based on the hierarchical cooperative strategy of multi-agent system,a multi-spacecraft cooperative observation mission planning model is established.In order to ensure safe maneuvering and maintain formation configuration,centralized method is adopted to plan overall parameters such as control law parameters and expected path point parameters of each spacecraft,and distributed method is adopted to plan the missions of each spacecraft by means of anti-collision safety control algorithm.The results show that the cooperation of multiple spacecraft comes true through the proposed planning system.This paper studies the safety control and mission planning for the high risk of collision and coordination problem of multi-spacecraft cooperative operation,which has certain theoretical significance.The proposed dynamic anti-collision safety control algorithm and hierarchical collaborative programming method can effectively improve the safety of multi-spacecraft proximity operation and the efficiency of task completion,and can provide reference for the design and control of multi-spacecraft proximity operation in the future.