Backstepping-Based Six Degrees of Freedom Adaptive Control for Spacecraft Tracking a Noncooperative Target

In this paper, the six degrees of freedom adaptive tracking control for chaser spacecraft with uncertainty and disturbance to approach a noncooperative target are studied. The system equations with coupled relative translation and relative rotation are modeled. Considering the unknown inertia uncertainties and state-dependant disturbances, a backstepping-based adaptive tracking control law is developed to achieve high-precision proximity operations between chaser and noncooperative target. The unknown inertia and disturbance are estimated by adaptive update laws. The properties of the developed control law are discussed through the comparison of simulation results.