Dimensional fault diagnosis for compliant beam structure assemblies

A model-based diagnostic methodology is proposed for the dimensional fault diagnosis of compliant beam structures in automotive or aerospace assembly processes. In the diagnosis procedure, the product measurement data are used to detect and isolate dimensional faults caused by part fabrication error in compliant beam assemblies. The proposed method includes a predetermined fault patterns model and a fault mapping procedure. The fault patterns are modeled by the diagnostic vectors derived from the inversed stiffness matrix of the beam structure. The fault mapping procedure combines principal component analysis (PCA) of measurement data and fault pattern recognition using statistical hypothesis tests. Verification of the proposed method is presented through simulations and one case study.