A Unifying Approach to Human Pilot Modelling

Abstract

The data base supporting models of the human pilot participating in well defined single-axis tracking tasks can be considered essentially Complete as regards the effects of aircraft dynamics and disturbance characteristics. Despite this fact, certain fundamental and interesting questions have only recently been addressed or remain unanswered. Among these are the following: (1) By what mechanism does the human pilot generate the dynamic equalization required in tracking tasks? (2) How might the human utilize an “internal model” of the environment in these tasks? (3) What causes nonlinear pilot behavior when controlling higher-order dynamics? (4) How do manipulator characteristics effect human pilot dynamics and performance? (5) How does the human organize his perceptions in pursuit as opposed to compensatory tracking? (6) How does the human quantify his subjective impressions of task difficulty or handling qualities? With these and related issues in mind, a “structural model” of the human pilot is discussed. The model is shown to be descriptive rather than predictive in nature and is shown to have its basis in an hypothesized feedback structure involving the human neuromuscular system. Selecting pertinent examples from experimental results reported in the literature, the questions just raised are discussed and the potential of the structural model to answer them in a unified manner is demonstrated.