Reliable Aerial Manipulator Control for Physical Interaction With Input Saturation Considerations

Designing effective controllers for aerial manipulators remains challenging due to discontinuous disturbances from physical interactions and inherent motor thrust limitations. This paper introduces a disturbance-observer-based control framework that explicitly addresses both challenges to achieve reliable aerial physical interaction. We begin by modeling the full dynamics of an aerial manipulator comprising a hexarotor platform with tilted motors and a rigidly attached robotic arm. Building on this model, we design a disturbance observer to mitigate external disturbances and model uncertainties, and we integrate a sliding-mode control law to ensure robustness against discontinuous disturbances. Furthermore, we develop a reference compensation strategy that adapts the desired pose and twist in real time to satisfy motor thrust constraints. To validate the proposed approach, we conduct three aerial manipulation simulations involving physical contact with the environment. The results demonstrate that our controller achieves stable and robust physical interaction, even under severe disturbances and actuator saturation.