An adaptive relative pose controller for docking
ports of two uncertain spacecraft in autonomous rendezvous
and docking is developed. A novel relative translational and
rotational model represented in the chaser body-fixed frame is
derived firstly based on the classical Newton-Euler equations.
Based on the proposed model, a six-degrees-of-freedom adaptive
control law is presented based on norm-wise estimations for
the unknown parameters of two spacecraft to decrease the
online computational burden. Meanwhile, an adaptive robust
control input is designed by introducing an exponential function
of states to improve the response performance with respect
to the traditional adaptive robust control. Moreover, a linear
anti-windup compensator is employed to ensure the bounded
performance of the control inputs. The explicit tuning rules for
designing parameters are derived based on the stability analysis
of the closed-loop system. It is proved in Lyapunov framework
that all closed-loop signals are always bounded and the pose
tracking error ultimately converges to a small neighborhood of
zero. Simulation results validate the performance of the proposed
robust adaptive control strategy
