Substantial improvements in material processing and manufacturing techniques in recent years necessitate the introduction of effective and efficient nondestructive testing (NDT) methods that can seamlessly integrate into day-to-day aircraft and aerospace operations. Lamb wave-based methods have been identified as one of the most promising candidates for the inspection of large-scale structures. At the same time, there is presently a high level of research in the field of autonomous mobile robotics, especially in simultaneous localization and mapping (SLAM). Thus, this paper investigates a means to automate Lamb wave-based NDT by positioning sensors along a planar structure through mobile service robots. To this end, a generalized method for the mapping of plate structures using scattered Lamb waves by means of frontier exploration is presented such that an autonomous SLAM-capable NDT system can become realizable. The performance of this novel Lamb wave-based frontier exploration is first evaluated in simulation. It is shown that it generally outperforms a random frontier exploration and may even perform near-optimal in the case of an isotropic, square panel. These findings are then validated in laboratory experiments, confirming the general feasibility of utilizing Lamb waves for SLAM. Furthermore, the versatility of the developed methodology is successfully demonstrated on a more complexly shaped stiffened panel.

中文翻译：

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通过前沿勘探基于兰姆波的板块结构绘图

近年来材料加工和制造技术的重大改进需要引入有效和高效的无损检测 (NDT) 方法，这些方法可以无缝集成到日常飞机和航空航天操作中。基于兰姆波的方法已被确定为检测大型结构的最有希望的候选方法之一。同时，目前自主移动机器人领域的研究水平很高，特别是在同步定位和建图（SLAM）方面。因此，本文研究了一种通过移动服务机器人沿平面结构定位传感器来自动化基于兰姆波的无损检测的方法。为此，提出了一种通过前沿探索使用散射兰姆波绘制板块结构的通用方法，从而可以实现具有自主 SLAM 能力的 NDT 系统。这种基于兰姆波的新型前沿探索的性能首先在模拟中进行评估。结果表明，它通常优于随机边界探索，甚至在各向同性方形面板的情况下可能表现接近最佳。这些发现随后在实验室实验中得到验证，证实了将兰姆波用于 SLAM 的一般可行性。此外，所开发方法的多功能性已在形状更复杂的加筋板上成功展示。这种基于兰姆波的新型前沿探索的性能首先在模拟中进行评估。结果表明，它通常优于随机边界探索，甚至在各向同性方形面板的情况下可能表现接近最佳。这些发现随后在实验室实验中得到验证，证实了将兰姆波用于 SLAM 的一般可行性。此外，所开发方法的多功能性已在形状更复杂的加筋板上成功展示。这种基于兰姆波的新型前沿探索的性能首先在模拟中进行评估。结果表明，它通常优于随机边界探索，甚至在各向同性方形面板的情况下可能表现接近最佳。这些发现随后在实验室实验中得到验证，证实了将兰姆波用于 SLAM 的一般可行性。此外，所开发方法的多功能性已在形状更复杂的加筋板上成功展示。