When the flies feel the threat, the flies fly away very quickly. How do the flies see the threat and react quickly? Researchers at the School of Precision Instruments and Photoelectronics Engineering of Tianjin University have developed a new visual system for simulating insects with bionic compound eyes. They have found that insects may detect the trajectory of an object according to the intensity of light emitted by the object. The research results were published in the International Journal Optics Letters, which was featured by the Optical Society (OSA), and then reproduced by the American Association for the Advancement of Science (AAAS), Science Daily and the World Science and Technology Research News Network (Phys.org) and other important academic media.
The Optical Society (OSA) official website report
The insect compound eye vision system has the advantages of small size, light weight, large field of view, high time resolution, and sensitive target detection, which makes it have advantages that other imaging methods cannot match. The research team used a single-point diamond cutting method to make a bionic compound eye with 169 sub-eyes on polymethyl methacrylate. This bionic compound eye simulates the insect’s compound eye function, and each sub-eye can be used as an independent visual receptor. The sub-eye has a radius of about 1 mm and the 169 sub-eyes form a component of approximately 20 mm with an angle of view of up to 90 degrees.
By placing a conical light guide device between the curved surface lens and the image detector that makes up the compound eye, the researchers can make the compound eye with curved surface receive light from different angles evenly. Associate Professor Le Song, who is in charge of the project, explained: “This new bionic compound eye is more similar to biological compound eye in its ability to receive light uniformly, so it can better imitate the real biological mechanism.”
Schematic diagram of bionic compound eye system
At present, the mechanism of fast perception of target trajectory by insect compound eyes is not clear. In order to measure the three-dimensional trajectory of a target using bionic compound eyes, the researchers divide the space into grids using the overlapping field of view of each sub-eye. Then, they make the moving target appear in the specific space position of the distance compound eye system, and locate the target based on a light intensity distribution algorithm. They found that the compound eye system could quickly provide three-dimensional coordinates of objects.
Development of Bionic Compound Eye System and Legend of Target Detection
“Human beings need complex image information to determine the location of objects, and by simulating insect compound eye function, we find that insects may be able to locate objects according to their brightness.” Professor Song Le said, “Insects can respond quickly to threats by processing only the light and dark gray information of images. This simple detection mechanism is very suitable for the brain processing ability of insects, thus helping them avoid predators.” Researchers also found that the farther the target is from the compound eye system, the lower the accuracy of location, which explains why most insects are myopic.
As early as 2005, under the leadership of Professor Fengzhou Fang, a Yangtze scholar and chief scientist of 973 Project, since the establishment of the Micro-nano Manufacturing Research Team (MNMT) of Jingyi College of Tianjin University, with “De, Diligence, Quietness and Precision” as the core values of team development, we have been committed to the design and manufacture of optical free-form surfaces, biological manufacturing, and so on. The basic theory research and application development of micro-nano processing, ultra-precision processing and detection have already possessed the manufacturing capability of high-precision surface compound eye device. In the design, manufacture and application of bionic compound eye system, the team has published dozens of papers in recent years, and applied for more than ten national invention patents. The results have had a great impact on the international community. The new bionic compound eye developed in this paper can quickly detect the spatial position of objects, and can be used in intelligent robots, driverless vehicles and other fields in the future. The research team also plans to embed localization algorithms into platforms such as integrated circuits, so that the system can be integrated into other devices. In order to reduce the cost, the large-scale batch production method of compound eye lens is also being studied.
This study was funded by the National 973 Program (2011 CB706700), the National Natural Science Foundation (51175377) and the Tianjin Natural Science Foundation (12JCQNJC02700).
Article: Yelong Zheng, Le Song*, Jingxiong Huang, Haoyang Zhang, Fengzhou Fang. “Detection of Three Dimensional Trajectory of Object Based on Curved Bionic Compound Eye”, Optics Letters, 2019, 44(17), 4143-4146