Spacecraft Optimal Attitude Control by means of Reaction Wheels

This paper presents an optimal attitude maneuver by means of Reaction Wheels to achieve desired attitude for a Satellite. At first, Dynamic Equations of motion for a satellite with three Reaction Wheels as its active actuators has been educed, and then State Equations of this system has been obtained. In derivation of equations, coupling of Reaction Wheel electrical equations with dynamic equations of satellite motion, and Reaction wheel saturation avoidance approaches are considered. Then an optimal attitude control with the LQR method has exerted for a distinct satellite by its Reaction Wheels. As a result of simulation has presented an optimal effort by calculated Gain matrix to achieve desired attitude for chosen Satellite. It shows that satellite becomes stable in desired attitude with a low energy and time consumption.