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tethered-satellite-system--tss
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Optimal Retrieval Trajectory of Tethered System of Space Debris for Maximize the Aerodynamic Heating
, M.Sc. Thesis Sharif University of Technology ; Malaek, Mohammad Bagher (Supervisor)
Abstract
In this study, a model for the optimal routes for the recovery of space debris is expressed. The dynamic model using a binary system consisting of satellites and orbital debris containment space is extracted. Trastrhay available on satellite and aerodynamic drag on the system circuit changes the whole system and the entry of debris into the thick atmosphere began to burn.This circuit must be optimized. The thrusters are assumed as variable optimization problem. After simulation of optimization, it follows that by changing the initial value thrusters, Trastrhay the optimal cost function changes. Also, indicating the final height of system affects on parameters, thrusters and the cost...
Fault Tolerant Model Predictive Control of Tethered Satellite System
, M.Sc. Thesis Sharif University of Technology ; Asadian, Nima (Supervisor)
Abstract
In this thesis, a control method to cope with the fault in the two-satellite two-tether satellite systems has been proposed to avoid failing the mission in the case one tether is torn. A new model for the tethered satellite system with two tethers has been developed to show the effects of tethers’ tension forces in the attitude dynamics. One of the main features of this model is the ability of changing the tethers’ connection points to the co-satellite for attitude control purposes. As a result, tethers’ tension forces are used as control actions to reduce the fuel consumption. The introduced coupled tethered satellite system has been controlled using the model predictive control method....
Dynamics of Tethered Satellite Formation Around Binary Asteroids
, M.Sc. Thesis Sharif University of Technology ; Assadian, Nima (Supervisor)
Abstract
Studying of binary asteroids because of achieving data of existence sources in the world persuades to investigate about tethered satellite formation around binary asteroids in future missions. About 20 percent of asteroids around the sun are binary asteroids. It is going to analyse dynamics of tethered satellite around Didymos binary asteroid. Light mass of the asteroid is good reason to consider gravitational harmonic perturbation, and leads to attention about solar radiation pressure depends on distance in modelling of the dynamical system. It will be zonal harmonics up to second order and sectoral. Satellites are such a particle as an assumption; that is why attitude motion of satellites...
Anti-sway control of tethered satellite systems using attitude control of the main satellite
, Article Acta Astronautica ; Volume 111 , June–July , 2015 , Pages 300-307 ; 00945765 (ISSN) ; Salarieh, H ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In this study a new method is introduced to suppress libration of a tethered satellite system (TSS). It benefits from coupling between satellites and tether libration dynamics. The control concept uses the main satellite attitude maneuvers to suppress librational motion of the tether, and the main satellites actuators for attitude control are used as the only actuation in the system. The study considers planar motion of a two body TSS system in a circular orbit and it is assumed that the tethers motion will not change it. Governing dynamic equations of motion are derived using the extended Lagrange method. Controllability of the system around the equilibrium state is studied and a linear LQG...
Dynamic and Control of Tethered Satellite Systems
,
M.Sc. Thesis
Sharif University of Technology
;
Salarieh, Hassan
(Supervisor)
Abstract
In this work dynamic behavior of a two body TSS with main satellite as rigid body is studied and effects of tether elasticity and tension on the satellite dynamic are indicated in station keeping phase and circular orbit. Also a simplified modeling is introduced which could be used in nonlinear controller design. Lagrange and extended Lagrange method is used to derive equations of motion. It is shown that longitudinal vibration of tether has small effect on satellite attitude and angular velocity and because of high frequency it can be decoupled from satellite dynamic. In the simplified model, orbital motion is decoupled from equations of TSS and main satellite dynamic. Effect of decoupling...