Bell 412 System Identification: Comparing Methods and Tools

Over the last decades system identification has become a standard method for developing rotorcraft models from flight test data. Using data from the Bell 412 Advanced Systems Research Aircraft (ASRA) helicopter operated by the National Research Council of Canada, different identification methods and tools are applied to a common database. The identified 6-DoF rigid-body models at one flight condition are compared in detail regarding eigenvalues and the match in both time and frequency domain. The development of a global model from point models that were identified at the different flight conditions is described. Finally, several possible extensions of the rigid-body models are investigated assessing corresponding improvement in model fidelity.