Attitude reference generation for leader-follower formation with nadir pointing leader

In this paper we present a solution for real-time reference generation for a leader-follower spacecraft formation. The solution is assuming a nadir pointing leader spacecraft and a follower spacecraft which is complimenting the measurement of the leader by tracking the point located at the intersection on the Earth surface between Earth center and leader spacecraft. Desired relative attitude, angular velocity and angular acceleration are generated in real-time based on the relative position, velocity and acceleration between the leader and follower spacecraft. A passivity based PD+ controller is derived and the equilibrium points of the closed-loop system are shown uniformly asymptotically stable, and simulation results are presented to show the performance of both the reference generation method and the control law during a formation reconfiguration.