Dynamic Interaction Enables Quadrotor UAV to Break Windows

Safe control of quadrotor UAVs during window-breaking tasks remains challenging due to unforeseen disturbances. In this article, a safety-aware control framework is proposed for quadrotor UAVs operating in uncertain contact environments. Specifically, a sensorless force estimator is developed to estimate interaction force within a finite time frame, providing prompt force feedback for force tracking. Furthermore, a safety layer is introduced at the top of the nominal controller to maintain stability when the quadrotor UAV becomes unstable due to contact loss. The safety layer is formulated by integrating an energy tank with control barrier functions. Constraints on energy and power are imposed to achieve stable regulation of power flow between the energy tank and quadrotor UAV. Simulations and real-world experiments are conducted to illustrate the feasibility and effectiveness of the proposed scheme.