Advanced Smart Sensing Node with Acoustic-Based Connectivity for Spot Welding in the Automotive Industry

Automotive industries are nowadays characterized by the omnipresence of metallic structures and spot welding machines. These two characteristics bring attention to a set of different problems that are pointed out in this paper. The main problem is the reaching of a certain control level on the quality of a welding process. Over the past years, research in the smart welding field found the solution to this problem in monitoring the voltage and current values during a welding process by observing the temporal profiles of these two quantities. Based on the signature left by the welding machines, the quality of the weld can be traced by comparing it with a model one. In addition, a problem that can be found in these types of harsh environments is the communication of the measured voltage and current level to a central unit to reach a higher level of monitoring. In this paper, the problems with the communication among metallic structures are pointed out, and an innovative acoustic communication approach is proposed. In particular, the idea of building an acoustic communication setup is discussed. Subsequently, an acoustic noise measurement during the welding process is carried out, and the results are presented. Finally, in the last part of the work, the idea of evaluating the impact of acoustic noise on acoustic communication is discussed.