Thermal State Simulation And Health Assessment Intelligent Method Research Of LEO Satellite

As our space technology gradually evolves,LEO satellites as high-tech products,is widely used in economic construction and national defense construction.However,with the complexity of space missions and the internal integration of satellites increases,heat sources increase gradually and there is interference between each other.When it reaches a certain extent,the normal operation of satellites will be seriously affected.Therefore,it is important to simulate and evaluate the thermal and health status of orbiting satellites.This study takes the LEO satellite as the research object and realises the fast calculation of the temperature field of the whole satellite during the on-orbit motion by constructing a thermal state simulation model.At the same time,the health state of the satellite is evaluated and analysed by intelligent methods of fuzzy inference and reconfigurable characteristics of the satellite,and the satellite state under the influence of typical uncertainties is analysed.Finally,the LEO satellite thermal state simulation and health assessment system is built to visualise the simulation results.Primary research work consists of the following four aspects:1.Research on the thermal state modeling and dynamic simulation methods of satellites based on numerical computation.Aiming at the key problems of satellite thermal state analysis,this study establishes the satellite in-orbit motion model and the calculation model of space heat flux.The satellite is divided into n+3 unit nodes,namely the shell,the radiator,the inner and the n components.The temperature calculation model is established by comprehensively considering the heat transfer relationship between each node,and the satellite thermal state is simulated by combining the example.The simulation results and variation rules are analyzed and discussed.2.A satellite health status assessment method based on fuzzy reasoning and reconfigurable characteristics is proposed.This study adopts the strategy hierarchy of "components-> subsystems-> whole satellite" to evaluate the satellite health status.Considering the influence of the internal parameter gradient variation and the structural characteristics of the system on the satellite health status,an intelligent method of fuzzy inference is used to evaluate the components health status at the components level,and from the components level to the subsystems level and from the subsystems level to the whole satellite level in combination with the reconfigurable characteristics of the satellite.3.Changes in the thermal and health condition of the satellites due to uncertainties will be analyzed.In order to reduce the adverse effects of uncertain factors on the satellite and improve the utilization rate of resources and optimize the system performance,the satellite state under the influence of typical uncertain factors such as coating degradation,thermal conductivity disturbance,internal heat source change and thermal load was evaluated and analyzed.4.A set of LEO satellite thermal state simulation and health assessment system is developed.Based on B/S architecture,combined with the satellite thermal state model and health state assessment method proposed in this study,the LEO satellite thermal state simulation and health assessment system is developed.After inputting the required parameters and designing fuzzy rules,simulation results of the thermal state and the real-time health state changes of the satellite are dynamically displayed in a visual way.The analysis results of the model and algorithm proposed in this study can reasonably reflect the real-time changes of the thermal state and health state of LEO satellites on orbit,and provide reference for the thermal design and health state evaluation of satellites.