Use of Wavelet Scalograms to Characterize Rotorcraft Pilot-Vehicle System Interactions

Wavelet-based scalograms can be used to characterize pilot behavior in the presence of changing pilot-vehicle system dynamics. Scalograms provide a time-varying presentation of pilot input and rotorcraft output power signatures, akin to a time-varying power spectral density. A recent piloted simulation study was conducted to investigate the impact of rotorcraft added dynamics on precision hover task performance. Five evaluation test pilots participated in the study conducted on the NASA Ames Vertical Motion Simulator. In the evaluation process, the pilots were first presented a simplified, uncoupled baseline rotorcraft model. Added rotorcraft dynamics in the form of a lead/lag second order dipole pair were then introduced. The impact of the added dynamics on task performance was explored as dipole damping was varied from run to run and, for selected cases, during a single run. Scalograms were used to quantify pilot-vehicle system interactions in the presence of changing rotorcraft dynamics.