Design and Simulation of an Orbit Control System

Abstract

The contemporary era of satellite deployment, characterized by an unprecedented increase in the number of satellites in Low Earth Orbit (LEO), underscores the importance of advanced orbit control systems. These systems are vital for the sustainable and precise operation of satellite and satellite constellations across various applications. This thesis enhances this aspect of space technology by focusing on the design and analysis of orbit control systems for satellite station-keeping, a critical task for ensuring the operational longevity and reliability of satellites in LEO. Addressing the challenge of developing a robust control system, this research navigates through the complexities of space dynamics to propose a solution that enhances the efficiency of satellite maneuvers in LEO. The study introduces an array of functional models created in Scilab, including models for positioning sensors utilizing Global Navigation Satellite System (GNSS) measurements, orbit determination algorithms, and thruster systems encompassing electric propulsion. These models are specifically designed to simulate real-world space conditions by incorporating realistic errors and variabilities. Subsequently, the thesis simulates these models within a comprehensive Scilab environment, examining both individual and collective satellite operations. This leads to the formulation and optimization of control algorithms dedicated to maintaining precise orbit trajectories, particularly focusing on two advanced control strategies: the Linear Quadratic Regulator (LQR) and Clohessy-Wiltshire (CW) based trajectory control. These methodologies are analysed for their effectiveness in precise trajectory management and fuel efficiency. A thorough evaluation of the proposed control systems is conducted, assessing fuel consumption, manoeuvre accuracy, and the frequency of necessary adjustments. Through detailed comparative analysis, the study elucidates the efficacy of the electric thruster and its corresponding control strategies, offering valuable insights into their applicability for diverse satellite missions. The findings of this research illuminate the complexities of orbit control systems and significantly contribute to the field of satellite engineering. By demonstrating potential enhancements in efficiency and sustainability for satellite operations, this thesis lays the groundwork for future innovations in orbit control systems. The implications of this work are broad, suggesting a transformative impact on the management and operation of satellite constellations in LEO.