Electro-mechanical molten pool control for adapting deviations in the process boundary conditions during automated gas shielded metal arc welding

在MSG焊接自动化过程中，如何在不同的工艺边界条件下保证焊缝质量是一个主要问题。虽然目前有一些策略可以通过传感器（通常处于领先位置的传感器）检测这些偏差，并通过纠正焊枪位置和/或调整焊接参数来自动补偿，但这只能在有限的工艺限制内实现（通常改变焊接速度）。然而，手工焊接的适应策略提供了一个优势，根据手工焊工的经验，它可以在相当大的过程窗口中使用，从而补偿与过程边界条件的较大偏差。这些策略主要包括调整焊接速度，改变焊枪的定位和/或方向，以及适应当地的能源和填充材料供应。手工焊工根据自己的训练和多年的经验，凭直觉决定适合每种情况的策略。因此，该项目的目的是将手工焊接的程序转移到自动焊接过程中，从而大大扩展了在工艺边界条件发生偏差时适应焊接过程的工艺限制。向自动化焊接过渡的一个重要先决条件是在人工焊工方法的基础上开发适应策略，其本质上是针对焊缝池的开发和控制。此外，必须制定基于焊接专家数字化知识的决策标准，以确定何时以及在何种情况下应该使用合适的适应策略。

In the automation of MSG welding processes, there is a major problem in ensuring weld seam quality despite varying process boundary conditions. Although there are currently strategies by which these deviations are detected by sensors (usually sensors in leading position) and automatically compensated by correction of the welding torch position and/or adaptation of the welding parameters, this is only possible within limited process limits (usually varying the welding speed). Adaptation strategies for manual welding, however, offer the advantage that, depending on the manual welder's experience, it can be used in considerably larger process windows and thus compensate for larger deviations from the process boundary conditions. These strategies mainly involve adapting the welding speed, changing the positioning and/or orientation of the welding torch as well as the locally adapted supply of energy and filler materials. The decision as to which strategy is suitable for each individual case is made intuitively by the manual welder based on his training and many years of experience.The aim of the project is, therefore, to transfer the procedure for manual welding to the automated welding process and thereby considerably extend the process limits for adapting the welding process in case of deviations in the process boundary conditions. An important prerequisite for the transfer to automated welding is the development of adaptation strategies based on the manual welder's approach, which is essentially aimed at the development and control of the weld pool. Furthermore, decision criteria based on digitized knowledge of welding experts about when and in which situation a suitable adaptation strategy should be used have to be developed.