操船者の眼球運動特性と見張り

抄録

We have already reported on the characteristics of a lookout in the daytime and at night by using the eye-movement analyzer called "eye-pointer". This time, we show the remarkable points added the other new data in the twilight with the measurement of the eye-movement by the same way. The remarkable points of the characteristics of the eye-movement related a lookout of ship's operator are as follows ; 1. The extent of fixation point shown by the ellipse with the standard deviation of the fixation angle has a normal tendency being wide horizontally. But in case of the Jet-foil's navigator in the daytime and on the open sea, the extent of fixation point has a special tendency being wide vertically. 2. The average interval of fixation time at night and in the twilight is about 150msec. That in the daytime is about 60msec. On the other hand, by the average speed of sight-line displacement of the eye, the eye-movement of ship's operator is saccade movement in the daytime and in the twilight, and that is smooth pursuit movement at night. Ship's operators conduct the lookout affairs by looking and searching the obstructive targets at night and in the twilight, and by seeing them in the daytime, because of more or less of the visual informations from the ship's environment. 3. The relation every one unit observing duration (33msec) in the daytime between the average speed of sight-line displacement of the eye and the number of fixation point can be shown by the approximate formula ; Y=1827/X+31.8 (Y : the number of fixation point, X : the speed of sight-line displacement of the eye <average rate> (deg/sec), correlation coefficient : -0.82] 4. In the twilight, the average fixation time is more longer and the average speed of sight-line displacement of the eye is more faster, both than that in the daytime. So it is very difficult to catch the visual informations of the targets at sea, in the twilight, ship's operators should have special cautions for preventing ship's collision.