Analytic and test results of the Rotor/Vehicle State Feedback Investigation indicate that feedback networks can be used successfully to simulate the important flying quality and ride comfort aspects of mechanical flapping-feathering coupled arrangements. Factors such as accuracy of tip-path-plane resolution, computer time lags, control system hysteresis, and actuator dynamics are either negligible, can be compensated for, or do not sufficiently influence the results to alter this general conclusion. A ruggedized commercial computer, installed on a CH-53A helicopter, was programmed successfully to handle a wide variety of rotor and fuselage feedback schemes and related operating logic which was investigated during the flight test phase of this study. The program cycle time was approximately twice as fast as the most demanding sampling rate studied (24 samples per revolution). The investigation indicates that the dynamically varying first harmonic contributions (tip-path-plane coefficients) of main rotor blade flapping can be resolved from blade flapping measurements when data supplied to the resolver meet particular requirements. (Author)
Flight Investigation of Rotor/Vehicle State Feedback
1974
173 pages
Report
No indication
English