Kimihiro NISHIO^*, Hiroo YONEZU, Masahiro OHTANI^†, Hitoshi YAMADA^‡ and Yuzo FURUKAWA

Department of Electrical and Electronic Engineering, Toyohashi University of Technology, 1-1, Tempaku-cho, Toyohashi 441-8580, Japan

(Received August 9, 2002; Accepted January 14, 2003)

We proposed an analog network for motion detection of an approaching object with simple-shape recognition based on the visual systems of lower animals. Locusts can detect an approaching object by performing a simple process in a descending contralateral motion detector (DCMD) existing in their brain, which senses the increase in size and expansion velocity of the image projected on a retina just before collision. The responses correspond to the approaching velocity and direction. Frogs can recognize a simple shape by performing a simple process in a tectum and thalamus existing in their brain based on retinal information; this is called the Ewert von Seelen model. The proposed network was constructed with simple analog metal–oxide–semiconductor (MOS) circuits. Simulation results with a simulation program with integrated circuit emphasis (SPICE) showed that the network was able to detect the approaching velocity and direction, and also recognized simple shapes such as a circle, square, triangle and rectangle.

Key words: edge detection, motion detection, shape recognition, descending contralateral motion detector (DCMD), Ewert von Seelen model

^*E-mail: nishio@dev.eee.tut.ac.jp
^†Present affiliation: Department of Electrical Engineering, Nara National College of Technology, 22, Yata-cho, Yamatokoriyama, Nara 639-1080 Japan.
^‡Present affiliation: Research Laboratories, DENSO CORPORATION, 500-1, Minamiyama, Komenoki-cho, Nissin, Aichi 470-0111 Japan.