Safety-Critical Quadrotor Navigation Using Fourth-Order Control Barrier Functions

This research proposes a safety controller for quadrotors in cluttered environments using fourth-order control barrier functions (CBFs) that incorporate full nonlinear dynamics, including attitude dynamics and torque-level actuation. The method resolves mixed-relative degree issues through integral high-order CBF techniques, enabling direct control over attitude behavior and obstacle avoidance. The approach is validated in simulation and real-world flight experiments, demonstrating reliable constraint satisfaction and safety improvements.