Classification of items in a walk-through metal detector using time series of eigenvalues of the polarizability tensor
Classification of items in a walk-through metal detector using time series of eigenvalues of the polarizability tensor
复制标题
使用极化张量特征值的时间序列对步入式金属探测器中的物品进行分类
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
A. Visa
中科院分区：
文献类型：
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作者：
J. Kauppila;T. Ala;J. Vihonen;Juha Jylhä;M. Ruotsalainen;A. Järvi;A. Visa
在过去的十年中，机场的安全条例已被设定到一个新的水平。随着旅客人数的不断增加，有效而快速的安检控制对21世纪的安检系统提出了很高的要求。在本文中，我们将介绍一种新的金属探测器的概念，使不仅检测，而且隐藏的项目进行分类，虽然他们的方向和准确的位置是未知的。我们的新原型步行通过金属探测器产生相互正交的均匀磁场，以便测量的偶极矩允许分类，即使是最小的项目，具有高精度的实时。不随物体的不同旋转而变化，分类基于极化率张量的特征值，该特征值包含关于物品的信息（大小、形状、方向等）;作为进一步的新奇，我们把特征值作为时间序列。在我们的实验室设置中，没有对物品可能位于的典型位置进行假设。在这种情况下，90%的危险和无害物品，包括刀，枪，枪零件，皮带等，根据安全组织，被正确分类。造成的错误分类被解释为所讨论的项目的电磁特性太相似。通过使用机械臂和我们的原型系统进行的实证测试，验证了理论处理和模拟。在未来，最先进的系统可能会大大加快安全控制，提高安全性。
During the last decade, the safety regulations of the airports have been set to a new level. As the number of passengers is constantly increasing, yet effective but quick security control at checkpoints sets great requirements to the 21st century security systems. In this paper, we shall introduce a novel metal detector concept that enables not only to detect but also to classify hidden items, though their orientation and accurate location are unknown. Our new prototype walk-through metal detector generates mutually orthogonal homogeneous magnetic fields so that the measured dipole moments allow classification of even the smallest of the items with high degree of accuracy in real-time. Invariant to different rotations of an object, the classification is based on eigenvalues of the polarizability tensor that incorporate information about the item (size, shape, orientation etc.); as a further novelty, we treat the eigenvalues as time series. In our laboratory settings, no assumptions concerning the typical place, where an item is likely situated, are made. In that case, 90 % of the dangerous and harmless items, including knives, guns, gun parts, belts etc. according to a security organisation, are correctly classified. Made misclassifications are explained by too similar electromagnetic properties of the items in question. The theoretical treatment and simulations are verified via empirical tests conducted using a robotic arm and our prototype system. In the future, the state-of-the-art system is likely to speed-up the security controls significantly with improved safety.