Coordination control design for formation reconfiguration of multiple spacecraft

This study investigates the high precision control design of formation reconfiguration for a group of spacecraft with obstacle/collision avoidance and unknown disturbances. First, by utilising the null-space-based method, a set of pre-designed velocities are calculated for each spacecraft to perform the tasks with the obstacle/collision avoidance task has a higher priority. Second, a task-based adaptive non-singular fast terminal sliding mode coordination control algorithm (TANCCA) is proposed, which can guarantee all the spacecraft to implement the formation reconfiguration while avoiding obstacles/collisions under an unknown disturbed environment. To solve the chattering problem caused by the discontinuity of TANCCA, a modified TANCCA (MTANCCA) is then developed, which is continuous and chattering-free. Finally, the authors use the solution to the formation reconfiguration control problem for six spacecrafts in a circular Low Earth Orbit at 600 km altitude. The results of the simulation show that the MTANCCA is successful in achieving the obstacle/collision avoidance, disturbance rejection, fast convergence, and high control precision without any collisions or rules broken.