Research On The Satellite Formation Reconfiguration And Keeping Under J2 Perturbation

With the rapid development of space technology,with its advantages of advanced technology and broad application prospect,small satellite formation has rapidly developed into a brand-new in-orbit operation mode of space vehicles.Similarly,satellite formation puts forward higher requirements for current space technology,and there are still many problems to be solved in dynamic modeling,formation reconstruction,formation maintenance and other aspects.Taking the formation of low earth orbit satellites as the research background,the dynamics modeling,formation reconstruction and formation maintenance of satellite formation are studied and discussed under J2 perturbation in this paper.The research content of the subject mainly includes several aspects:Firstly,in the reference orbit coordinate system,the multi-satellite formation problem is decomposed into the two-body motion of a single chief satellite and a deputy satellite.The perturbation of J₂ was incorporated into the external disturbance term,and the nonlinear dynamic equation was substituted for derivation and linearization,so as to obtain a more accurate linear relative dynamic model,which laid a theoretical and model foundation for the subsequent research on formation reconstruction and formation maintenance of satellite formation.According to the dynamics analysis of the two-body motion of the satellite formation,the space formation of the satellite formation is designed.This paper analyzes the relative motion characteristics of satellite formation on the reference orbit of space circle,introduces several common formation flight modes,analyzes the characteristics and configuration conditions of each formation flight configuration in detail,and draws corresponding formation flight graphics,which provides formation basis for subsequent formation reconstruction and formation maintenance.Secondly,on the basis of the relative motion dynamics equation of the satellite formation linearized under the perturbation of J₂ established above,the configuration reconstruction of the satellite formation is described.The fuel optimization problem is transformed into a two-point boundary value problem by introducing the Hamiltonian function and the covariant variables.The multi-shooting method was used to solve the two-point boundary value problem.In order to obtain a more accurate initial value,the initial value of the costate variable was obtained by combining the improved pigeon group evolutionary algorithm.The problem of formation reconstruction of satellite formation under J₂ perturbation is transformed into a two-point boundary value problem by using the multiple shooting method and the improved pigeon group evolutionary algorithm.At the same time,the particle swarm optimization（pso）algorithm is applied to the formation reconstruction and compared with the control strategy of the joint algorithm.Then,the formation of the reconstructed satellite formation is maintained.Based on LQR theory and sliding mode control theory,two kinds of controllers are designed to maintain the formation.The difference is that the LQR controller can only keep the satellites in the formation in a fixed relative position in the space configuration,that is,static.The sliding mode controller can not only maintain the static state,but also keep the satellite in the ideal position of change in the configuration,that is,the dynamic state.The two formation control strategies are compared and verified by numerical simulation.The advantages and disadvantages of the two control methods and their respective applications are analyzed.Finally,VC++is used to design and build simulation system software for scene simulation.The simulation of satellite formation reconstruction and maintenance was carried out in different design scenarios,and the effectiveness of the joint algorithm and sliding mode control in the dynamic formation maintenance was verified.