Electromagnetic Mechanism Design And Eddy Current Magnetic Field Modeling For Spacecraft Despinning

Space,as a new physical space for human activities,has the advantages of high location,global coverage and no border,which accelerates the use of space by all countries in the world.The failed spacecraft not only occupies orbit resources but also threatens other spacecraft.Hence,it is imperative to study the technology of towing off orbit.In general,the failed spacecraft rotates at a high speed,and despinning is the first step of towing off orbit.The despinning technology of failed spacecraft can be divided into contact and non-contact type.Among them,electromagnetic despinning technology has been widely concerned for its advantages of non-contact control,no plume pollution,and no fuel consumption.Aiming at the failed spacecraft electromagnetic despinning,the electromagnetic despinning mechanism based on Halbach configuration is designed.Based on the theoretical calculation and finite element software simulation,the electromagnetic mechanism is optimized and analyzed,and the magnetic field model of the mechanism is derived.At the same time,the eddy current induced magnetic field of the spherical shell target is deduced theoretically and the characteristics of eddy current force and torque are analyzed.A measuring scheme of eddy current magnetic field array is proposed and a ground testing system is built.Finally,the ground test is performed to evaluate the dispinning performance of electromagnetic mechanism.(1)This study deeply analyzes the impact of different Halbach configurations on the external magnetic field,and carries out a reasonable magnetic circuit design to reduce the divergence of magnetic field.In addition,the basic component analysis is made so that the magnetic field generated by the despinning mechanism is confined to the side facing the failed spacecraft,and the final optimization scheme is designed according to the constraints.(2)This study conducts electromagnetic vortex despinning analysis of failed spacecraft,deduces the magnetic field model of the induced eddy current generated by the spherical shell target under the external magnetic field,carries out the kinematics simulation by using Ansys Maxwell electromagnetic simulation software,and analyzes the despinning capability of designed despinning mechanism.(3)The eddy current magnetic field measurement scheme is designed to determine the distribution space and spacing of magnetic measuring instruments so as to improve the accuracy and reliability of data collection.Apart from that,the experimental measurement data is analyzed and magnetic field inversion modeling is conducted.Furthermore,the inversion results and theoretical model are compared to find out the errors and improve the theoretical model.(4)This study establishes the ground test system and uses the electromagnetic mechanism as the magnetic field generating device,the high-precision and high-speed rotating platform as the target of despinning.Besides,the despinning performance of the electromagnetic mechanism is verified through the combination of finite element simulation and ground test.In short,taking the spacecraft despinning as the background,this study carries out electromagnetic mechanism design and eddy current magnetic field modeling of failed spacecraft.The mechanism and design concept obtained can provide model and method reference for the electromagnetic despinning scheme design,system analysis,and in-orbit test verification of in-orbit failed spacecraft.