Preliminary Results Towards Fidelity Evaluation of an In-flight Simulator

This paper presents the analysis of the fidelity obtained when performing in-flight simulations of the Bo-105 helicopter in forward flight with the Active Control Technology/ Flying Helicopter Simulator (ACT/FHS). The results are preliminary in the sense that they are based on the real-time and fully non-linear simulation model of the ACT/FHS in DLR’s helicopter simulator and not in the ACT/FHS itself. Yet, a flight test proven controller setting is used in the simulations. The ACT/FHS, the model-based controller, and the command model are briefly presented. The precision of the MBC for each control/response axis is evaluated quantitatively through frequency-domain methods, time-domain methods and handling quality analysis. A perceived fidelity evaluation process based on piloted simulations and comparative flight tests with the Bo-105 is presented. This process is first applied to evaluate the model-following precision and second to evaluate the fidelity of the in-flight simulation. The results of the evaluations are used to identify strengths and weaknesses of the in-flight simulation for each response axis, including cross-couplings.