Spacecraft coordination control in 6DOF: Integrator backstepping vs passivity-based control

In this paper, we present three nonlinear control solutions for 6DOF spacecraft formation control, adopted from Euler–Lagrange system theory. The quaternion parametrization results in dual equilibrium points in the closed loop system, and the controllers are proved to render these uniformly asymptotically stable. We also present a theoretical comparison of the three control solutions, together with simulation results to visualize the performance of the controllers.