Extended-State-Observer-Based Terminal Sliding Mode Tracking Control for Synchronous Fly-Around with Space Tumbling Target

Abstract EN

This paper presents a robust controller with an extended state observer to solve the Synchronous Fly-Around problem of a chaser spacecraft approaching a tumbling target in the presence of unknown uncertainty and bounded external disturbance.

The rotational motion and time-varying docking trajectory of tumbling target are given in advance and referred as the desired tracking objective.

Based on dual quaternion framework, a six-degree-of-freedom coupled relative motion between two spacecrafts is modeled, in which the coupling effect, model uncertainties, and external disturbances are considered.

More specially, a novel nonsingular terminal sliding mode is designed to ensure the convergence to the desired trajectory in finite time.

Based on the second-order sliding mode, an extended state observer is employed to the controller to compensate the closed-loop system.

By theoretical analysis, it is proved that the modified extended-state-observer-based controller guarantees the finite-time stabilization.

Numerical simulations are taken to show the effectiveness and superiority of the proposed control scheme.

Finally, Synchronous Fly-Around maneuvers can be accomplished with fast response and high accuracy.