Department Neuroethology/Sensory Ecology, Institute of Zoology, University of Bonn, 53115 Bonn, Germany.
Bioinspir Biomim. 2019 Apr 8;14(3):035002. doi: 10.1088/1748-3190/ab08a6.
Underwater object inspection by optical sensors is usually unreliable in turbid or dark environments. Here, we designed a biomimetic 'electric camera', inspired by weakly electric fish Gnathonemus petersii, which successfully use active electrolocation for this task. The device probed nearby objects with a weak electric field and captured 'electric images' of the targets by processing the object-evoked field modulations. The camera-based electric images strongly resembled those available to G. petersii. Furthermore, by extracting the fish's analytical cues from these images, close objects could be reliably analysed. Based on the level of 'image blurring' short distances of electrolocation targets, spheres of different sizes and material were estimated. Natural targets, fish or plants, were identified irrespective of their size or distance by their two individual 'electric colours' derived from electric images. Furthermore, we introduce an image cue, called the 'electric outline', which provided information resembling a target's optical contour. Our results indicate that bio-inspired electric imaging principles provide promising cues for sensor-based, short-range object inspections in murky waters. By resembling the electric imaging applied by G. petersii our device can also be used for 'reverse biomimetics', revealing imaging cues that so far have not been considered for weakly electric fish.
水下物体的光学传感器检测在浑浊或黑暗的环境中通常不可靠。在这里，我们设计了一种仿生“电摄像机”，灵感来自弱电鱼电鳗，它成功地将主动电定位用于这项任务。该设备用弱电场探测附近的物体，并通过处理目标引发的场调制来捕获目标的“电图像”。基于图像的电图像与电鳗的图像非常相似。此外，通过从这些图像中提取鱼类的分析线索，可以可靠地分析近距离的目标。基于“图像模糊”的程度，即电定位目标的短距离，可以估计不同大小和材料的球体。通过从电图像中得出的两个个体“电颜色”，可以识别出无论大小或距离的自然目标，例如鱼类或植物。此外，我们引入了一个称为“电轮廓”的图像线索，它提供了类似于目标光学轮廓的信息。我们的结果表明，受生物启发的电成像原理为浑浊水中基于传感器的短距离物体检测提供了有前途的线索。通过类似于电鳗应用的电成像，我们的设备还可以用于“反向仿生学”，揭示迄今为止尚未考虑用于弱电鱼的成像线索。
