LED警光灯の視認性向上のための感性指標に基づく点滅パターン解析

抄録

Recently, the number of emergency vehicles equipped with light-emitting diode (LED) warning lights has increased. Unlike traditional beanie lights, LED warning lights can display various flickering patterns because these patterns are controlled by computers. The purpose of this study was to develop flickering patterns that had a high level of visibility. Lighting time (ON time), no-lighting time (OFF time), light intensity and rising time (UP time) were controlled by a microcomputer. Further, the visibility of each LED flickering pattern was evaluated quantitatively. Specifically, the visibility of the flickering patterns using the psychophysical measure of “conspicuity (easy to stand out)” from Bradley-Terry paired comparison model was identified. Results showed that OFF time had a significantly greater influence on visibility than ON time. Moreover, the flickering pattern with 66 msec of OFF time provided optimal visibility, regardless of the ON time, by making the visibility map, which represented the degree of visibility between ON time and OFF time. Therefore, the ideal combination between ON time and OFF time was determined.