Assessment of a Scalogram-Based PIO Metric with Flight Test Data

This paper presents a wavelet scalogram-based metric, which identifies pilot-induced oscillations (PIOs) from flight and when they have occurred. The method considers the time-varying peak pilot input power as a function of the controlled-element phase at the frequency of the peak power, all of which are elements of the defined PIO signature. A flight-test database generated in the evaluation of fixed-wing PIO mitigation concepts is first used to assess the utility of the proposed approach. Further independent evaluation and validation using a previously unassessed aircraft configuration and evaluation maneuvers are made using data generated from pilot-in-the-loop simulations of the XV-15 at the University of Liverpool's HELIFLIGHT simulation facility. The results of the assessments found that the new metric was successful at identifying correctly both PIO and non-PIO cases.