Decay Rate and Workload: Elemental Bases of HQRs and PIO Ratings
Publication Date
1-1-2025
Document Type
Conference Proceeding
Publication Title
Vertical Flight Society 81st Annual Forum and Technology Display
Abstract
A quantitative understanding of the perceptual elements of handling qualities rating brings us to the heart of pilot control. In previous work it was shown that pilot induced oscillation ratings (PIORs) were a strong linear function of the closed loop, dominant mode decay rate of the modeled pilot-vehicle system. While PIORs are based solely on the degree that oscillation degrades the task, the handling qualities rating (HQR) scale employs aggregate performance criteria and three apparently distinct sensations: workload, compensation, and controllability. However, in practice the pilot must modulate control in real time based on an instantaneous sense of performance. It is incumbent to model these four perceptions if the objective is to reproduce the manner and resolution with which a pilot assigns HQRs. The current work examines the same offset landing task that was conducted in two separate piloted studies: 1) Flight, using the Calspan variable stability NT-33A aircraft, and 2) Fixed and motion-based simulation, using the NASA Vertical Motion Simulator (VMS). The substantial differences in pilot ratings between the inflight and simulation studies hitherto could not be accounted for. The perception-based theory developed herein predicts pilot ratings that match well the two studies' ratings. It is demonstrated how acceleration washout (employed in most motion simulators) could produce decay rate sensing ambiguity within the vestibular system and require the visual system to be used for control. A biomechanical feedback model is developed that computes dynamic limb tension and damping from the neuromuscular system which is then integrated with the feel system to produce a stick force disturbance in response to aircraft motion. This model is flight-data-validated, and the decay rate associated with the neuromuscular mode is used as a metric to successfully predict the occurrence of roll-ratchet (a higher frequency PIO phenomenon).
Department
Psychology
Recommended Citation
Edward Bachelder. "Decay Rate and Workload: Elemental Bases of HQRs and PIO Ratings" Vertical Flight Society 81st Annual Forum and Technology Display (2025).
