Cybernetic analysis of perspective flight-path display dimensions

Perspective flight-path displays, presenting the future trajectory to be flown through a three-dimensional tunnel-or highway-in-the-sky, are likely to become the primary flight displays of future cockpits. A crucial design parameter is the size of the virtual tunnel as it determines the tradeoff between pilot path-following performance and workload. An information-theoretical and control-theoretical analysis is presented that aims at gaining an in-depth understanding of the effects of the tunnel size on pilot manual control behavior. The theoretical findings are verified in two pilot-in-the-loop experiments, one conducted in a fixed-base simulator and one in real flight. In the simulator experiment, it is shown that through pilot multiloop model identification the effects of reducing the tunnel size can be directly related to pilot/vehicle bandwidth and stability margins. The use of pilot models allows an objective quantitative analysis of the effect of the tunnel size compared to the subjective, qualitative surveys conducted in the past. The flight-test experiment supports the main findings of the simulator experiment but also reveals that pilot performance in actual flight is less consistent and also lower than measured in the flight simulator.