Research On Capture Technology Of Tether-net For Space Targets

The increasing amount of space debris in orbit poses a great threat to spacecraft.Developing active removal technology for space debris has become a consensus among countries.Among various debris removal schemes,space tether-net has the advantages of low cost,wide practicality,large capture range,and high stability,and has become a highly focused debris removal scheme in the field of debris removal.In this thesis,space tether-net was taken as the research object,and the structural design and dynamic modeling were carried out,and the effectiveness of the proposed method was verified through simulation and experiment.The main work includes:Firstly,based on the background of non-cooperative space debris removal,the space tether-net system was designed.The system uses mechanical energy storage as the source of power,thereby reducing the overall size and weight of the system.At the same time,the space tether-net system design considered the net storage method,capture closure method,and overall configuration.Secondly,based on the centralized mass method and Kelvin-Voigt model,the tether dynamic model was improved to describe more tether posture information and improve the accuracy of the tether dynamic model,thereby reflecting the complex motion law of the composite body(the satellite and the captured object are connected by a tether,forming a single-sided constrained composite body).At the same time,to verify the space tether-net system’s capture process of space debris,a collision contact dynamic model was established based on a nonlinear damping model and MSBB detection.By combining the collision contact dynamic model with the space tether-net deployment dynamic model,the overall dynamic model of the space tether-net system was constructed.Then,the dynamic simulation of the space tether-net capture system was carried out to analyze and verify that the improved tether model can reflect the motion behavior of the composite body and the influence of the internal spiral structure of the tether after torsion on the tether dynamic characteristics.Under zero gravity conditions,the deployment process of the space tether-net at different launch angles was simulated,and the influence of different launch angles on the deployment of the space net was analyzed.At the same time,the capture process of the space tether-net system was simulated,and the influence of the limit rope length on the capture result and the reasonable range of values were analyzed.Finally,the designed parts were processed and assembled,and the ground test of the space tether-net capture system was designed.The deployment and capture test platform was set up.Through ground tests,the stability and effectiveness of the space tether-net capture system were verified.At the same time,the bending and torsion tests of the rope were carried out,and the dynamic simulation results of the second-order discrete tether model were compared with the test results to verify the effectiveness of the model.