Research On Rendezvous Trajectory Optimization And Relative Navigation Of Geostationary Earth Orbit Satellite

Due to the wide range of earth observation and high application efficiency,Geostationary Earth Orbit（GEO）satellites are widely used in military,civil and commercial fields,which have high strategic value.However,influenced by technical level and space environment and other factors,GEO satellites have frequent on-orbit failures,which seriously affect the performance of satellites and even lead to the failure of satellite functions,bringing huge economic losses and adverse social impacts.Meanwhile,the growing space debris occupies a large amount of orbital resources,which seriously threatens the safe operation of GEO satellites and the sustainable development of orbital space.In order to maintain the orbital environment and protect the safety of GEO space assets,it is urgent to develop the on-orbit service technology for GEO satellites,among which a high reliability,low cost and high accuracy to achieve the proximity rendezvous to GEO targets is the prerequisite and the key to successfully carrying out the on-orbit service mission.In order to meet the mission requirements,the trajectory of the service satellite during the proximity rendezvous should be absolutely safe under all circumstances,and the relative navigation technology in this phase should have high accuracy and reliability.This thesis takes the proximity rendezvous phase of the on-orbit service mission of GEO satellites as the research background,and takes the trajectory optimization and relative navigation problems existing in the rendezvous mission as the main research objects.It investigate the theoretical problems such as relative motion modeling of GEO satellites under the influence of main perturbations,the optimization design of GEO satellites safe rendezvous trajectory,the angles-only relative navigation method and the relative navigation approach of hybrid thrust maneuvering target.Based on a set of ground semi-physical simulation system,the theoretical methods in this thesis are validated.The following are mainly accomplished.（1）The relative motion modeling of GEO satellites under the influence of multiple perturbations is studied.A detailed analysis of the influence of the main perturbations on the GEO satellites is presented.An extended set of quasi-nonsingular mean relative orbital elements is proposed to describe the relative motion of the two satellites.On this basis,a relative motion modeling method including the main perturbations is proposed,and the systematic matrices of the relative motion effects of the Earth non-spherical gravitationalJ₂,J₃ term perturbations,the third-body perturbations and the solar radiation pressure（SRP）perturbation are derived respectively,and then an analytical relative motion model is given.The linear transformation from the mean relative orbital elements to the osculating relative orbital elements and from the osculating relative orbital elements to the relative position/velocity are given,avoiding complicated iterative calculations.Under the given initial conditions,two typical GEO mission scenarios are simulated by using the derived relative motion model,and the influence mechanism of different perturbations on the mean relative orbital elements is obtained.The improved model is applied to the GEO satellites relative position keeping control,and the results show that the proposed model has high accuracy（2）The optimal design problem of safe rendezvous trajectory for satellites is studied.Considering the influence of navigation and control deviations,a quantitative safety evaluation index is proposed,and the calculation method is given.From three aspects of objective function,optimization variables and constraints,a safe rendezvous trajectory optimization model that takes into account the optimal fuel and safety is constructed.An algebraic criterion is introduced to determine the passive safety constraints,which avoids the huge computation of numerical iterations.Through numerical simulation,the relationship between fuel consumption and the safety index is analyzed and summarized,and a proposed scheme that can be used for actual rendezvous missions is given.The simulation of the thrustless free flight phase shows that the rendezvous scheme only considering the fuel optimization has potential collision risk,and the optimization scheme considering the safety index can ensure the safety of the rendezvous trajectory.（3）The angles-only relative navigation problem is studied.The camera offset installation method is adopted to improve the observability of the system,and an observability analysis method of‘quasi linear’transformation is used to give the camera offset installation conditions with relative distance observable.In order to solve the problem of sample dilution inherent in the particle filter algorithm,an improved firefly algorithm is proposed to optimize its resampling process,and the convergence of the optimization algorithm is proved.On this basis,an improved particle filter algorithm is proposed,which effectively improves the estimation performance of the algorithm and provides a reference scheme for solving the problem of angles-only relative navigation.（4）The relative navigation of GEO hybrid maneuvering targets is studied.Considering the common thrust configuration of GEO satellites,the typical maneuver characteristics are analyzed.Aiming at the problem that IMM algorithm is difficult to match the model of hybrid maneuvering targets,an interactive model set considering three cases of no maneuver,impulse maneuver and limited thrust maneuver is established,which covers the typical maneuvering characteristics of GEO satellites.Furthermore,aiming at the problem of model transition probability approximation of IMM algorithm,an adaptive modified model transition probability calculation method based on acceleration estimation is proposed,which enhances the role of matching model.The performance of the proposed improved algorithm is greatly improved compared with the traditional IMM algorithm,which can effectively realize the relative navigation of GEO hybrid thrust maneuvering targets.（5）The ground simulation verification problem of the proposed theoretical method is studied.Based on the existing experimental conditions,a set of ground semi-physical simulation verification system for space rendezvous is designed and built.The system functions and requirements are discussed in detail,the specific composition and working principle of the system are given,and the corresponding relationship between the scale of the system and the simulation ability is given according to the principle of system scale simulation.Based on the built simulation platform,the simulation schemes of the safe rendezvous trajectory optimization method,the angles-only relative navigation method and the hybrid thrust maneuvering target relative navigation method are designed respectively,and the angles-only relative navigation method proposed in this thesis is tested to verify the correctness of the theoretical method and the platform design.This thesis systematically analyses and studies the trajectory optimization and relative navigation problems in the GEO satellites rendezvous mission.The proposed methods and the obtained results presented in this thesis are of great practical significance for future missions for GEO satellites,such as on-orbit maintenance,space debris removal and space attack and defense,et al.