چكيده به لاتين
The improvement in the space industry, especially in the satellite field, have led to the formation of satellite-based systems in order to optimize the use of space and reduce the cost of space missions. Satellite formations are a combination of several satellites which designed to perform a common mission. One of the main pillars of the success in the formation missions is the determination of their relative orbits and consequently, their control.
The main objective of this thesis is to model the behavior of the satellites, determine their position by GPS, use the GPS signal phase data to calculate their relative position and velocity, and to study and implement a precision and automatic control system for satellites of low altitude orbits and also control in order to prevent the collisions of the satellites. Relative motion modeling of satellites is derived from the expansion of single-satellite motion. This modeling represents the behavior of the leading and following satellites by position vector and relative velocity, as well as by the classical orbital parameters. In order to optimize the use of GPS receivers, the technique of calculating relative position and velocity data is more accurately compared with the phase of the GPS signals, in which the effect of the error generated by the ionosphere and the bias error of the receiver and receiver clocks and other noise in positioning, is omitted by differential methods. Also, in order to control the relative position of the satellites, in order to achieve optimal position or maneuvers for reconfiguration of the formation, LQR control methods and state feedback linearization with regard to fuel consumption are used. Numerical simulations confirm the validity of proposed methods and techniques.
Keywords: Satellite Formation Flying, Relative Orbit Determination and Control, GPS Signals, LQR Controller, State Feedback Linearization
