Abstract
The present work reports the results of our experiments aimed at estimating the distribution of the response delay time in human intermittent control over unstable mechanical systems. A novel experimental paradigm: balancing an overdamped inverted pendulum was used; the overdamping eliminates the effects of inertia and, therefore, reduces the dimensionality of the system. The created simulator of balancing a virtual pendulum by a human operator via computer mouse movement makes the pendulum (stick) invisible when the angle between it and the upward position is less than 5o. It enabled us to measure directly the delay time as the time lag between the moment when the pendulum becomes visible and the moment when a subject starts to move the mouse. Eight persons (male students) were involved in the experiments. The collected experimental data are presented in the form of the delay time histograms. For the analyzed system it is demonstrated, in particular, that (i) the response delay time may be treated as a random variable distributed within a wide interval. Its lower boundary is estimated as less than 50 ms, which corresponds to the limit delay time determined by human physiology. The upper boundary is estimated as 500-600 ms, which is about typical values of the response delay time when a controlled system exhibits complex dynamics. Besides, the obtained results enable us to hypothesize that the response delay in human intermittent control may be determined by cumulative actions of two distinct mechanisms, automatic and international, endowing it with complex nonlinear properties.
