Pilot-helicopter-slung-load coupled dynamics and fuzzy gain scheduled adaptive anti-swing strategy

This study presents a fuzzy gain scheduled adaptive anti-swing strategy for helicopter slung load systems to resolve the inherent conflict between load swing stability and command tracking performance. A high-fidelity nonlinear model of the pilot–helicopter–slung load system (PHSLS) is developed, incorporating detailed rotor and flight dynamics, a modern control system with cable angle feedback, and a structural pilot model based on human physiological characteristics. Based on this model, the coupled dynamics of the PHSLS are analyzed, revealing that the inherent trade-off between stability and controllability arises from competing objectives between the fuselage and cable feedback control loops. Specifically, effective suppression of load swing oscillations requires a 39.2 % increase of maximum pilot control input, indicating a notable degradation in handling qualities. To mitigate this conflict, a fuzzy gain scheduler (FGS) is designed to adaptively adjust feedback gains based on real-time pilot input aggressiveness and load swing intensity, enabling dynamic prioritization between stability and controllability during flight. Numerical and piloted simulations show that the FGS suppresses load swing as effectively as the fixed-gain controller optimizing load swing damping, while maintaining roll tracking accuracy similar to the fixed-gain controller optimizing command tracking performance. These results confirm the effectiveness of the proposed strategy in enhancing load damping without compromising pilot control authority, supporting its potential for deployment in advanced slung load operations.