摘要
The tethered TSAR(tomographic synthetic aperture radar)system is a group of tethered SAR satellites that can be rapidly deployed and provide a stable baseline for 3-dimensional topographic mapping and moving target detection.Successful deployment is critical for TSAR tethered system.This paper discusses the deployment strategy for a 3-body chain-type tethered satellite system in a low-eccentric elliptical orbit.Two deployment strategies are discussed.Then,the tension on the tether is used to deploy it to the desired length and suppress its sway motion,resulting in an underactuated and input-constrained system.Hierarchical sliding mode control(HSMC)with anti-windup technology is employed to overcome the above challenges.In addition,the proposed approach includes the use of a disturbance observer to estimate the second derivative signal and a robust differentiator to estimate the sliding surfaces of the unacted subsystem.Finally,the effectiveness of the proposed deployment strategy is verified by MATLAB/Simulink.
基金
sponsored by the National Natural Science Foundation of China(grant number 62173273)
the Natural Science Basic Research Plan in Shaanxi Province of China(grant number 2020JC-19).
