Modified Adaptive Control for Multi-Spacecraft Attitude Coordination Problems

The distributed control of spacecraft attitude coordination problems is developed in this paper. An adaptive sliding-mode (SM) controller is designed to steer the attitude of multiple spacecrafts to synchronously reach zero. Then a modified chattering-free controller is proposed to eliminate the chattering of control inputs caused by the switching function. By utilizing the Lyapunov stability theory, we can prove that the presented approach ensures the multi-spacecraft attitude converge into a limited range. Finally, numerical examples are provided to illustrate that the modified control approach can achieve high control accuracy with eliminating the chattering in the presence of external disturbances and model uncertainties.