Engineering Implementation Of Sosm Algorithm For Controlling Geostationary Satellites Orbit

Most satellites in operation lie in the geostationary orbit. This is a circular orbit of radius 42, 242km from the centre of Earth and lying in the plane of the equator. To an observer on the ground, a satellite in Geostationary orbit remains at the same fixed position in the sky. Geostationary satellite experiences forces and torques that cause it to change its position and orientation or attitude in space. There is therefore need to use thrusters or magnetic torques to re-position the satellite correctly in orbit. The study deals with the problem of controlling a satellite orbit position while optimizing fuel expenditure. The work proposed in this study aim to design robust second order sliding mode controller for satellites orbit positioning to overcome chattering phenomena in classical sliding mode control algorithm, while preserving the invariance property of sliding mode. The sliding approach is applied to geostationary satellite. The effectiveness of the controller is demonstrated through simulation