Attitude Control of Satellites with Reaction Wheels and Its Formation Keeping

In the satellite attitude dynamics control, the reaction wheel as actuator is modeled graphically by suitably linking it with DC motor characteristics, and the attitude control is accomplished by PID and more accurately by LQR with less time. The stability properties of the attitude plant dynamics are analyzed by creating a Routh table and the general conditions for its asymptotic stability aspects are proposed. The effect of J2 on the formation flight between two identical chief and deputy satellites in terms of change in classical orbital parameters is simulated graphically. The relative error from the initial formation is characterized in both orbital and Cartesian frames. The required amount of impulsive thrust for minimizing drift from original trajectory is calculated so as to keep the formation as such in or around a low earth orbit in the midst of J2 perturbation effect through graphical display of error patterns.