Modeling Human Pilot Adaptation to Flight Control Anomalies and Changing Task Demands

Abstract

A control-theoretic model of the human pilot as an adaptive element in a flight control system is presented. An earlier version of the model has been discussed in the literature for use with single-axis linear, vehicle system descriptions, including an application to a two-axis task with a linear vehicle model. The current study expands the model’s applicability to multiaxis, nonlinear systems. Three illustrative examples are presented: 1) a single-axis control problem with a transfer function description of the controlled-element dynamics; 2) a two-axis flight control problem involving a linear, highly coupled rotorcraft model including fundamental rotor degrees of freedom; and 3) a two-axis flight control problem involving a nonlinear, coupled aircraft model with dynamics patterned after the subscale NASA Langley Research Center’s Generic Transport Model. The ability of the refined adaptive pilot model to accommodate significant and sudden variations in elements of the flight control system, as well as departed flight, is demonstrated through computer simulation. Particular attention is paid to ensuring that the adapted pilot model obeys the dictates of the crossover model of the human pilot, before and after adaptation. A brief human-in-the-loop tracking study via a desktop simulation of the single-axis task is included in the study. Potential applications of the adaptive pilot model include the evaluation of adaptive flight control structures and evaluation of aircraft loss-of-control events.