Frequency-Response Identification of XV-15 Tilt-Rotor Aircraft Dynamics
Abstract
Timely design and development of the next generation of tilt-rotor aircraft depend heavily on in-depth understanding of existing XV-15 dynamics and the availability of fully validated simulation models. Previous studies have considered aircraft and simulation trim characteristics, but analyses of basic flight vehicle dynamics have been limited to qualitative pilot evaluations. This study has the following objectives: Documentation and evaluation of XV-15 bare- airframe dynamics; Comparison of aircraft and simulation responses; and Development of a validated transfer function description of the XV-15 needed for future studies. A nonparametric frequency-response approach is used which does not depend on assumed model order or structure. Transfer function representations are subsequently derived which fit the frequency responses in the bandwidth of greatest concern for piloted handling qualities and flight control system applications. This study involved the planning and execution of flight tests on the XV-15 aircraft and piloted-simulation for four flight conditions from hover to cruise. Improved test techniques and pilot-training procedures were devised. Analytical software tools were developed which allow identification of high-resolution spectral responses and the derivation and validation of multi-input/multi-output transfer function models. These techniques were applied in an extensive evaluation of the open-loop flight dynamics of the XV-15 aircraft and simulation mathematical models.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1987
- Accession Number
- ADA188345
Entities
People
- Mark B. Tischler
Organizations
- National Aeronautics and Space Administration