Research On Methods Of Maintaining And Control For Spacecraft Cluster Flight

Recent years,it has been a more and more important trend to complete space tasks with cluster flight,which can reduce the cost,increace the power and speed up the reaction.In this paper,based on the dynamics and control of spacecraft,relational research on spacecraft swarms and formation control has been studied.The main contents and accomplishments are as follows:1.Initial orbital elements,to maintain the distance between any two spacecrafts bounded,have been studied based on the feature of zonal harmonics and drag perturbation.Numerical simulations are used to validate the orbital design.2.Based on the equation of mean elements in perturbed motion,the trend of the change of the distance between two spacecraft is determined by the difference value of the average semimajor axes.By changing the difference value,the trend of the distance between two spacecrafts can be changed;therefore,cluster flight can be maintained.Simulations have been carried out to validate this method.3.The sufficient conditions of the periodical change of the orbital radius magnitude have been introduced,based on the orbital radius magnitude scope perturbed by J2.The method of single-impulse maneuvers to maintain the distance bounded,between two spacecrafts moving on equatorial orbits,has been studied,which has reduced the frequency of maneuvers.4.The method based on a virtual spring-damper mesh for formation control of spacecraft swarms has been studied.Spacecrafts are connected virtually by spring-damper pairs.The natural lengths of the springs are set according to the geometrical requirements of the desired formation.Under the assumption of linear translational dynamics and that the mesh topology is fixed and connected,the stability condition of the virtual spring-damper mesh controlled closed-loop relative motion system are derived by using algebraic graph theory.Simulations have been carried out,which show that the desired formations can autonomously evolve from random initial states by this method.