Multiresolution analysis for tool failure detection in CFRP/Ti6Al4V hybrid stacks drilling in aircraft assembly lines Articles uri icon

publication date

  • January 2024

volume

  • 206

International Standard Serial Number (ISSN)

  • 0888-3270

Electronic International Standard Serial Number (EISSN)

  • 1096-1216

abstract

  • This article presents a method for identifying Catastrophic Tool Failures during CFRP/Ti6Al4V hybrid stacks drilling in aircraft fuselage components assembly. The study is based on a real industrial case in the production system of a commercial aircraft section, where data was collected from the aircraft assembly line for 17 months. Over 30 different tool configurations were utilized in machining the aircraft section. However, the tool exhibiting the highest breakage rate, specifically a 4.6 mm diameter spiral fluted drill designed for CFRP/Ti6Al4V applications, was chosen for further analysis. This data collection included 69 samples of the selected cutting tool, revealing 19 instances of tool failure. The proposed detection method for spindle consumption signals utilizes Multiresolution Analysis (MRA) with Discrete Wavelet Transform (DWT) and Z-score technique. The research provides a comprehensive analysis of the use of DWT, explaining how the approximation and detail coefficients are obtained, which padding mode is suitable for the industrial case, the influence of the sliding process and filter bank length on the detection of sudden drops in the signal, and how to choose a suitable decomposition level in MRA based on the information provided by the scalograms. The confusion matrix results demonstrate the method's high performance, with Recall and Precision values equal to 1, which means that 100 % of tool failures were detected with no false positives. Additionally, the algorithm running time is 0.65 s, indicating that the method would apply to real-time tool failure detection in industrial machining production systems.

subjects

  • Mechanical Engineering

keywords

  • catastrophic tool failure; cfrp/ti6al4v drilling; discrete wavelet transform (dwt); multiresolution analysis (mra); real-time monitoring