Color Harmonization in Car Manufacturing Process

Abstract

One of the major cost factors in car manufacturing is the painting of bodyand other parts such as wing or bonnet. Surprisingly, the painting may beeven more expensive than the body itself. From this point of view it is clearthat car manufacturers need to observe the painting process carefully to avoidany deviations from the desired result. Especially for metallic colors wherethe shining is based on microscopic aluminium particles, customers tend tobe very sensitive towards a difference in the light reflection of different partsof the car. The following study, carried out in close cooperation with a partner fromcar industry, combines classical tests and nonparametric smoothing techniquesto detect trends in the process of car painting. The localized versions motivated by t-test, Mann-Kendall, Cox-Stuart and a change point test are employed in this study. Suitable parameter settings and the properties ofthe proposed tests are studied by simulations based on resampling methods borrowed from nonparametric smoothing. The aim of the analysis is to find a reliable technical solution which avoids any interaction from a human side.