Classification of gear damage levels in planetary gearboxes

Linear discriminant analysis (LDA) is a method of feature extraction that has demonstrated successful applications. The selection of the number of discriminant directions (r) is important to LDA, yet little attention is paid in the reported literature. In this paper a method is proposed for determining the optimal r in terms of the classification accuracy of support vector machine. The method is applied to identify gear damage levels in a planetary gearbox. Planet gears with four damage levels labeled as baseline, slight, moderate, and severe were used in lab experiments for data collection. Results demonstrate that the proposed method outperforms two reported methods and is effective to address the given problem.