Quality Monitoring in Robotised Welding using Sequential Probability Ratio test

Document type: Conference Papers
Peer reviewed: Yes
Author(s): Stefan Adolfsson, Ali Bahrami, Ingvar Claesson
Title: Quality Monitoring in Robotised Welding using Sequential Probability Ratio test
Conference name: 1996 IEEE TENCON Digital Signal Processing Applications Proceedings
Year: 1996
Pagination: xii+966 , 635-640, vol. 2
ISBN: 0780336798
Publisher: IEEE; New York, NY, USA
City: Perth
ISI number: A1996BJ42V00118
Organization: Blekinge Institute of Technology
Department: Dept. of Signal Processing (Institutionen för signalbehandling)
Dept. of Signal Processing S-372 25 Ronneby
+46 455 780 00
Authors e-mail: Stefan.Adolfsson@isb.hk-r.se
Language: English
Abstract: This paper addresses the problem of automatic monitoring the weld quality produced by robotised short arc welding. A simple statistical change detection algorithm for the weld quality, recursive sequential probability ratio test (SPRT), is used. The algorithm may equivalently be viewed as a cumulative sum (CUSUM) type test. The test statistics is based upon the variance of the amplitude of the weld voltage. It is shown that the variance of the weld voltage amplitude decreases when the welding process is not operating under optimal condition. The performance of the algorithm is evaluated using experimental data. The results obtained from the algorithm indicate that it is possible to detect changes in the weld quality automatically and on-line
Subject: Signal Processing\Detection and Classification
Keywords: quality monitoring; recursive sequential probability ratio test; cumulative sum type test; automatic monitoring; weld quality; robotised short arc welding; test statistics; weld voltage amplitude variance; welding process; algorithm performance; experimental data; parameter estimation