Effects of time delay in the visual feedback loop of a man-machine system. NASA CR-560.

This Thesis was aimed at studying the effects of time delay in the visual feedback loop of a man-machine system. A one-dimensional, step-type input, pursuit tracking experiment was developed to study these effects with transmission-type delays of zero to ten seconds. Thirty-six subjects participated in a series of tests that covered: seven different delays, two different levels of course complexity for each delay, learning, and open-loop conditions. It was found that tracking performance deteriorates non-linearly with increases in delay and that the magnitude of this performance degradation is a function of course complexity. The system cutoff frequency (fco) can be approximated by fco= w for all delays (T) which are much greater T ' than the operator reaction time and for all course complexities studied. A quasi-linear model for system performance was developed.