Impulse Control for Spacecraft Near Asteroid.

An impulse control method was proposed for the position keeping of a spacecraft near asteroid. Considering the gravity of the Sun and asteroid, the relative equation of motion of the spacecraft with respect to the asteroid was derived. The state transition matrix was used to describe the motion in the vicinity of the asteroid. A threshold control method was used to achieve the position keeping. The impulse controller was triggered when the position error was larger than a specified value. The results show that this method performs well for the position keeping, and the control period is long and propellant consumption is low. [ABSTRACT FROM AUTHOR]