Barrier Function Enhanced Geometric Controller for Safe Control of a Quadrotor UAV

Appropriate safety constraints, especially the state constraints, of a quadrotor unmanned aerial vehicle (UAV) are fundamental for safe control. Following the prevalent geometric controller, a new safe geometric control approach is proposed with state constraints for a quadrotor UAV, wherein the control barrier function (CBF) is integrated into the geometric controller to achieve safe control of the quadrotor UAV. Specifically, the CBF with respect to the states is constructed to establish the corresponding safety region. To satisfy the safety constraints, i.e., confining the states of the quadrotor UAV in the safety region rigorously, the control inputs calculated from geometric controller are refined with minimal modification by utilizing quadratic programming. The simulation study demonstrates the remarkable performance of the proposed approach in terms of the safety motion of a quadrotor UAV.