Data-Driven System Identification of an Active Helicopter Rotor Blade

Active control concepts for helicopter rotors, such as trailing edge morphing structures, offer significant potential for vibration reduction, noise mitigation, and performance improvement. An effective usage of these additional control inputs requires linear, control-oriented models that accurately capture the relevant rotor dynamics while remaining suitable for advanced model-based control design methods. This article presents a data-driven methodology to derive linear state-space representations from high-fidelity nonlinear rotor simulations, providing a systematic transition from detailed geometrical and aerodynamic modeling to control-oriented models. The proposed approach is based on subspace system identification and explicitly exploits the degrees of freedom provided by the algorithm to ensure both model fidelity and suitability for advanced control designs. The proposed methods are easily adaptable to real test data if flight measurements are available. The methodology is successfully demonstrated on a Bo 105 rotor blade simulator equipped with a trailing edge morphing structure.