VISIBILITY IMPROVEMENT BY CCT TUNABLE LED HEADLAMP UNDER THE ADVERSE WEATHER CONDITIONS

Since visibility is a very important factor under the adverse weather conditions like fog, rain, snow, and yellow dust and much more in nighttime, we need to understand the characteristics of visibility under the conditions.For this reason, we built two test-beds to simulate the adverse weather conditions, one for fog, rain, and snow and the other for yellow dust.We also developed a set of CCT tunable LED automotive headlamp for the evaluation of the visibility in different CCT headlamp.The CCT of the headlamp used for the experiments was 3000K and 6500K, and we measured the reflective luminance on the visual targets and calculated the relative luminance and contrast ratio.Additionally, we collected the subjective evaluation data.The results showed that the visibility was higher at low CCT in fog and rain but it was higher at high CCT in snow and yellow dust.Likewise, subjective evaluation showed the similar tendency.