Attitude Maneuver of a Flexible Satellite by Using Thrusters based on PD Controller

A satellite is designed to have a certain orientation with respect to the earth. The satellite keeps the solar panels pointed toward the Sun. For this reason, the satellite needs to be oriented when it reaches to a desired orbit after launching. Methods of maintaining orientation include small rocket engines, known as attitude thrusters. In the previous works, the satellite systems were considered to be rigid bodies. Attitude maneuvers of rigid satellites can be done without residual vibration. For flexible satellites, the attitude maneuver that does not regard to the system flexibility will induce large steady-state and transient vibrations. The large residual vibrations of the flexible satellite may disturb the conductance of its mission. When the residual oscillations of its attitude are greater than the permissible maximum values for an objective attitude, the requirements of the accuracy in pointing to the earth will not be satisfied. [1] This study is aimed to implement thrusters based on proportional-derivative (PD) controller for controlling attitude manuevers of precise-oriented satellite with flexible solar panels. These objectives were achieved by MATLAB simulation of attitude manuevers using thrusters based on PD logic. The fundamental of this work is to study on the equation of motion of the spacecraft with flexible appendages. The result for the PD controller is compared to the attitude manuevers using Bang-bang command control.