Underactuated Attitude–Orbit Coupling Control for Microsatellite Based on a Single Orbital Thruster

The feasibility of achieving complex under-actuated control based on a single orbital thruster with 2 inputs and 6 outputs is explored in this paper. The study applies this control method to the attitude-orbit coupling control of the micro-satellite during high-thrust orbital maneuver. A underactuated controller is introduced in the presence of partial states without direct inputs and multiple states actuated by single input. First, based on the orbit and attitude model, the input and underactuated characteristics are analyzed. Then, combining backstepping and hierarchical structure, an integral terminal sliding mode controller is designed to address the complex underactuation, while approximating the uncertainties using an adaptive fuzzy observer. Simulation results are presented to verify the underactuated attitude-orbit control performance of the proposed controller, thereby offering a crucial guarantee for the rapid maneuverability of micro-satellite.