Control And Experimental Research On Short Distance Deployment Of Tethered Satellite System

Tethered satellites, innovated for space probe, have proved to be of great significant in space science. Focus on the nonlinear dynamics of tethered satellite, this dissertation deals with the attitude control of a tethered satellite system with short distance deployment by dynamics modeling, numerical simulation and ground-based experiment.An attitude control problem concerning the in-plane motion of a tethered satellite system with short distance deployment is studied. Starting with nonlinear dynamic modeling of the tethered satellite system with controllable arm, dynamics similarity conditions between the ground-based experiments and the on-orbit system are obtained. By using the proportion differential feedback control strategy and robust control strategy, numerical simulations are performed to show the attitude motion of the controlled tethered satellite. Then, an ejection deployer of tethered satellite is designed to realize the deployment and retrieval. It consists of tension controller and driving mechanism,which stands out for simple construction, stable working performance and reproduceable process. This deployer provides facilities for the experiment. Afterwards, based on the physical simulation platform, dynamics similarity between the ground-based experiments and the on-orbit system is realized by thrust control. The ground-based test is conducted, the control of the attitude motion of tethered satellite and the tether swing is achieved by only using single rigid arm. The comparisons of experimental and numerical results well demonstrate that with the help of rigid arm can effectively control the deployment of the tethered satellite. Finally, a dynamic analysis is carried out to study the electrodynamic tether system. With the hollow cathode ejection device as the core, an initiative charge exchange system in ground-based vacuum environment is designed, which can simulate the space environment and reproduce the initiative charge exchange of the electrodynamic tether system.This dissertation deals with the control problem on short distance deployment of tethered satellite system. An ejection deployer is designed and the ground-based experiment is conducted. The comparison of the numeric and experiment demonstrates the effectiveness of the control strategy. Further more, an initiative charge exchange system in ground-based vacuum environment is designed, which provide the basis for the construction of the experimental platform.