Development of a new adaptive spot weld controller driven by an ultrasonic monitoring system.

在每辆汽车的4000到6000个点之间，电阻焊在任何汽车车身结构的构造中仍然起着至关重要的作用，它直接关系到乘员的安全率。尽管几十年来一直是汽车行业的主要加盟技术，但车身车间的快节奏环境仍然遗漏了一些关于过程质量和监控的重要信息，这是当今行业4.0标准的严格要求。“自适应”焊接控制器旨在填补这一空白，但目前的过程监控技术在提高检测率以及对常规焊接过程中的任何干扰做出迅速反应的能力方面似乎已经达到了极限。此外，新材料在汽车车身上的使用增加，如高强度钢和铝合金，也带来了一些挑战，因为与通常使用的传统钢相比，其焊接行为往往更不稳定。近年来，温莎大学诊断成像研究所(IDIR)开发了一种使用超声波的最先进的质量监测技术。内置在焊接电极中的压电式传感器正在向焊接薄板发送声波，并接收来自接头内部结构的反射。它可以确定熔化开始的时间和焊缝的主要尺寸。从这个意义上说，一个成功的可能性很高的解决方案涉及到结合使用这两种技术：在焊枪内部放置超声波传感器，从自适应焊接控制器触发决策算法。这一解决方案将是一个突破性的发展，因为它将实现“内在质量”的概念，显著提高装配过程故障(S)的检测率，并立即反馈给焊接控制器，后者将能够实时应用焊接参数的适当校正，从而实现“零缺陷”的概念。

Ranging from 4000 to 6000 spots for each single vehicle, resistance welding still plays a vital role in any automotive body structure construction, and it is directly related to the passenger safety rates. Despite being a major joining technology in automotive industry for decades, the fast-paced environment of a body shop still misses some vital information in terms of process quality and monitoring, which nowadays is a severe demand from the Industry 4.0 standards. The "adaptive" welding controllers were designed to fill this gap, but it seems that current process monitoring technologies have reached a limit in terms of their capacity to increase the detection rates, as well as the ability to promptly react to any disturbance in the regular welding process. Also, the increased use of new materials in automotive bodies, such as high strength steels and aluminum alloys, also brings some challenges, since its welding behavior tends to be more unstable compared to the conventional steels usually applied. In recent years, the Institute for Diagnostic Imaging Research (IDIR) at the University of Windsor has developed a state-of-the-art quality monitoring technology using ultrasound. A piezo-electric sensor, built into the welding electrode, is working to send sound waves into the welded sheets and receive the reflections from the internal structure of the joint. It allows the determination of when the melting begins and what are the main dimensions of the weld. In this sense, a solution with a high probability of success involves the use of both techniques combined: ultrasonic sensors placed inside the welding gun, triggering the decision-making algorithm from the adaptive welding controller. This solution will be a breakthrough development, since it will realize the "built in quality" concept, providing a significant increase in the assembly process fault(s) detection rates, as well as an immediate feedback to the weld controller, which will be able to apply the proper corrections of the weld parameters in real time, making it possible to implement the "zero defect" concept.