Gas sensor drift mitigation using classifier ensembles

Abstract

Sensor drift remains to be one of the challenging problems in chemical sensing. To address this problem we collected an extensive data set for six different volatile organic compounds over a period of three years under tightly-controlled operating conditions using an array of 16 metal-oxide sensors. We then adopted a machine learning approach namely an ensemble of classifiers to cope with sensor drift. For this particular application we chose support vector machine as our base classifier in the ensemble but, in principle, any other classifier can be used. Experiments clearly indicate the presence of drift in the sensors during the period of three years and that it degrades the performance of classifiers. However, the ensemble method that uses a weighted combination of classifiers trained at different points of time is able to cope well with sensor drift.