Improved Hamiltonian Adaptive Control of spacecraft

Spacecraft control is complicated by on-orbit inertia uncertainties. Considerable initial, on-orbit check-out time is required for identification of accurate system models enabling fine pointing. Smart, plug-n-play control algorithms should formulate smart control signals regardless of inertia. Adaptive control techniques provide such promise. Spacecraft control has been proposed to be adapted in the inertial frame based on estimated inertia to minimize tracking error. Due to unwieldy computations, later researchers suggested adapting the control in the body frame. This paper derives this later suggested approach using the recommended 9-parameter regression model for 3-axis spacecraft rotational maneuvers. Additionally, a new 6-parameter regression model is shown to be equivalent. A new, further-reduced 3-parameter regression model is demonstrated to yield similar performance. A new improved, simplified adaptive feedforward technique is developed and shown to provide superior performance. Following promising simulations, experimental verification is performed on a free-floating three-axis spacecraft simulator actuated by non-redundant, single-gimbaled control moment gyroscopes.