Adaptive Pose Tracking Control for Spacecraft Proximity Operations Under Motion Constraints

This is the authors' abstract. We don't add key points for this paper.

A novel adaptive control solution for pose tracking problems of spacecraft proximity operations subject to not only motion constraints but also parameter uncertainties is proposed in this paper. Specifically, the dual-quaternion formalism is employed to model the coupled translational and rotational dynamics of a leader–follower spacecraft formation. A class of artificial potential functions (APFs) is introduced to encode information regarding the underlying motion constraints that should be followed during proximity operations. Moreover, parameter uncertainties are normalized through the adoption of specially defined dual regressor matrices, and subsequently followed by the presentation of an APF-based non-certainty-equivalence adaptive control solution. The salient feature of the proposed adaptive structure is that, by employing dynamic scaling gains, the monotonic convergence of a certain term composed of parameter estimation errors and system states is ensured; this beneficial result along with the properties of the presented APF further avoid the stubborn local minimum problem associated with conventional APF-based controllers. Accordingly, the overall control scheme guarantees the arrival of the follower at the docking port of the leader with a prescribed relative pose while simultaneously accommodating for parameter uncertainties and complying with motion constraints.