Design Of One-dimensional Electromagnetic Docking System And Research On Its Sensorless Control

Space docking technology is the core and foundation of on-orbit service technology.Increasingly complex on-orbit maintenance and construction tasks put forward higher requirements for on-orbit docking technology.Traditional spacecraft docking technology based on thruster action relies on working fluid consumption and jet propulsion.Therefore,the working fluid ejected by the thruster will cause plume pollution and affect the precision instruments and sensitive devices on the spacecraft.In addition,the working medium that a spacecraft can carry is limited,which limits the mission range and service life of the spacecraft.More importantly,inertia is mainly used in the final stage of the docking,and a large impact force may cause many potential hazards.In recent years,electromagnetic docking technology based on electromagnetic force/torque control has gradually become a research hotspot.The electromagnetic docking technology can not only avoid the shortcomings of the traditional docking technology,but also the electromagnetic force has the characteristics of non-contact force,and can also be controlled continuously,synchronously and reversibly.Therefore,the electromagnetic docking technology can realize the flexible docking and safe separation of spacecraft,and has broad application prospects.Carry out research on electromagnetic docking technology to provide technical support for the on-orbit docking application of my country’s aerospace equipment.This paper summarizes and analyzes the current research status of electromagnetic docking technology at home and abroad.The analysis shows that the related research of electromagnetic docking technology mostly starts from the system and control level,and there is a lack of research and analysis on the electromagnetic docking coil design of the core component of the electromagnetic docking device.At the same time,the existing electromagnetic force model lacks universality,and the coupling characteristics of the two electromagnetic docking coils have not been studied in depth.Therefore,this paper studies the electromagnetic docking coil configuration,design,electromagnetic docking system modeling and analysis,and one-dimensional electromagnetic docking sensorless control algorithm.In this paper,the starting point is to increase the electromagnetic force density of the electromagnetic docking coil,analyze the configuration of the traditional electromagnetic docking coil,and point out the theoretical reasons for its lower electromagnetic force density.Through theoretical analysis,a new type of electromagnetic docking coil configuration with iron core with high electromagnetic force density is proposed,and several different configurations of electromagnetic docking coils are compared and analyzed.Focus on the problem that the traditional electromagnetic force model does not have universality,after experimental verification of the designed electromagnetic docking coil,the finite element calculation result is used as the electromagnetic force model,which improves the universality and accuracy of the electromagnetic force model.Because of the coupling characteristics between the two electromagnetic docking coils,the inductance is related to the relative distance between the two electromagnetic docking coils.This paper proposes an inductance estimation algorithm based on model reference adaptation,and designs a model reference adaptive position observer.Finally,the experimental platform and control system of the electromagnetic docking onedimensional system are designed,and the new electromagnetic docking coil and control algorithm described in this paper are theoretically analyzed and experimentally verified.