Aerospace Science and Technology
Amir reza Kosari; Alireza Akbar Attar; Peyman Nikpey
Abstract
In this study, the performance requirements influencing the orbital and attitude control system of a geostationary satellite in the station-keeping flight mode considering the coupling effect of both attitude and orbital motion is determined. Controlling and keeping the satellite in its orbital window ...
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In this study, the performance requirements influencing the orbital and attitude control system of a geostationary satellite in the station-keeping flight mode considering the coupling effect of both attitude and orbital motion is determined. Controlling and keeping the satellite in its orbital window have been done using a set of four thrusters located on one side of the satellite body, with considering the coupling effect of the attitude motion on orbital motion. The satellite’s orbital motion could be disturbed by the attitude motion in the allowable orbital window. The main factors conducting this behavior are derived utilizing the satellite attitude and orbital dynamic equations of motion. In the mathematical analysis of this study, the effects of environmental perturbations originating from the oblateness of Earth, third mass gravity like sun and moon, and solar radiation pressure on the satellite dynamic behavior are also considered. Afterward, the condition of using four installed thrusters on one side of the satellite and the reaction wheels in order to control the satellite orbital and attitude motion is investigated. To reduce the satellite attitude’s error, a proportional-derivative controller is employed to activate the reaction wheels properly. The satellite positions in north-south and east-west directions are controlled by a specific array of thrusters in order to maintain in its predefined orbital window. The required amount of velocity variations for a duration of one year via some simulation may demonstrate the effectiveness of the proposed approach in enhancing the orbital maintenance procedure of the satellite.
Farhad Fani saberi; Ali Kasiri
Abstract
This paper studies an output feedback second-order sliding mode control problem of spacecraft attitude control in the presence of the inertia tensor uncertainty and external disturbance. Mathematical modeling is presented based on spacecraft nonlinear equations of motion and quaternion parameters. Firstly, ...
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This paper studies an output feedback second-order sliding mode control problem of spacecraft attitude control in the presence of the inertia tensor uncertainty and external disturbance. Mathematical modeling is presented based on spacecraft nonlinear equations of motion and quaternion parameters. Firstly, a new sliding surface based on only attitude error is selected, then the standard second-order sliding mode control approach is followed. Finally, controller stability and tracking problem are guaranteed by choosing suitable auxiliary control input. The stability is proven by using concepts of a strong Lyapunov function and Lyapunov stability theory. Numerical simulations of attitude control of spacecraft equipped with 6 PWPF thrusters are given to demonstrate the performance of the proposed controller.
