Tau-Theory-Based Guidance Methodology for Helicopter Obstacle Field Navigation

This study presents a Tau-theory-based guidance methodology for obstacle avoidance in low-altitude, high-speed rotorcraft operations, especially within obstacle-dense and degraded visual environments (DVEs). A geometric approach is employed to develop the obstacle avoidance algorithms. The methodology considers both inner-loop and outer-loop guidance with a decision logic that determines the appropriate maneuver (turn, climb, or deceleration) based on real-time analysis of the environment and the helicopter’s operational limits. Extensive desktop simulations conducted in the MATLAB/Simulink environment, using FLIGHTLAB® high-fidelity nonlinear models and different pilot models, demonstrate the method’s ability to guide pilots with safe and efficient trajectories for obstacle field navigation. These findings lay the groundwork for potential real-world implementations in both manned and autonomous rotorcraft missions.