Relative attitude control in non-cooperative target formation flying

In non-cooperative target formation, the controlled satellite keeps pointing to the moving target on the basis of requirement of missions. To track a moving target, an approach is presented. It requires only relative positions and target attitude is computed with them. Then a relative angular velocity observer is designed and relative angular velocity is available. Attitude tracking without errors is accomplished by attitude tracking controller. Since a complete relative attitude control is composed of angle maneuver and attitude tracking, a hybrid controller is developed to deal with them. Simulation results show that the approach can track rapidly a moving non-cooperative target with little error.