Department of Electric Engineering and Information Technologies, University of Naples Federico II, 80125 Naples, Italy.
Institute for the Electromagnetic Sensing of the Environment, National Research Council of Italy, 80124 Naples, Italy.
Sensors (Basel). 2023 Jan 10;23(2):779. doi: 10.3390/s23020779.
Microwave imaging has been recently proposed as alternative technology for in-line inspection of packaged products in the food industry, thanks to its non-invasiveness and the low-cost of the equipment. In this framework, simple and effective detection/imaging strategies, able to reveal the presence of foreign bodies that may have contaminated the product during the packaging stage, are needed to allow real-time and reliable detection, thus avoiding delays along the production line and limiting occurrence of false detections (either negative or positive). In this work, a novel detection/imaging approach meeting these requirements is presented. The approach performs the detection/imaging of the contaminant by exploiting the symmetries usually characterizing the food items. Such symmetries are broken by the presence of foreign bodies, thereby determining a differential signal that can be processed to reveal their presence. In so doing, the approach does not require the prior measurement of a reference, defect-free, item. With respect to the quite common case of homogeneous food packaged in circular plastic/glass jars, numerical analyses are provided to show the effectiveness of the proposed approach.
微波成像是一种新兴的非侵入式技术，可用于食品工业中包装产品的在线检测，这主要得益于其设备的低成本。在这种情况下，需要简单有效的检测/成像策略来发现包装过程中可能污染产品的异物，以便实现实时可靠的检测，从而避免在生产线上出现延迟，并减少误报（无论是阴性还是阳性）的发生。在这项工作中，提出了一种满足这些要求的新型检测/成像方法。该方法通过利用食品通常具有的对称性来实现对污染物的检测/成像。异物的存在打破了这种对称性，从而产生了可以用来揭示其存在的差分信号。这样，该方法就不需要预先测量无缺陷的参考物品。针对在圆形塑料/玻璃罐中包装的均匀食品这一常见情况，提供了数值分析以展示所提出方法的有效性。
