Optimization and Experimental Validation of Automotive Bulbs

Abstract

In a vehicle, bulbs called the P-group are responsible for warning other drivers or pedestrians and they are known as signal bulbs. Signal bulbs have been used to emit warning and hazard signs in parts such as brake lights, direction indicator, hazard lights (night vision) as well as tail bulbs and car park alarms. There has been limited researches on the photometric characteristics of these lamps, but a review of these studies revealed that no detailed research has yet been done on optimizing these characteristics, and there is a scientific gap. In this study, factors affecting the service life and luminous flux were evaluated by using Taguchi design of experiments method. The results showed that the two factors of weight percent composition of bubble filling neutral gases and the volumetric efficiency of gases injected into the bubble had the most influence on the target parameters. Experimental results showed that the optimum composition of neutral gases injected into the bulb bubble can extend the bulb service life to approximately 341 h, which is three times the service life of a bulb with the inappropriate composition of fill gases. Then the optimum state of the service life and the luminous flux were determined to meet the reference standards. Although the service life and luminous flux parameters were able to reach 341 h and 513 lumens in the maximized state, however, in the optimum state with satisfying reference standards, the service life and luminous flux were 330 h and 463 lumens, respectively. Then, the bulb bubble filling with inert neutral gases and its effect on the bulb service life was investigated. The results showed that if the volumetric efficiency of gas injection increased from the normal 75%–100%, the service life of the test lamps would be improved by about 10%.