A hardware implementation of a biological neural system for target localization

The optical axes in an array of photoreceptors in the eyes of mantis shrimps have a particular skewing pattern that provides the animal with a monocular distance evaluation. A hardware (HW) device for target recognition was built based on the mathematical model of the biological visual system. The pattern of inputs was simulated by an array of glass fibers connected to phototransistors. In the biological system inputs are picked up by an integrating nerve fiber, in the HW model by an RC network with compartmental threshold devices. The network state is read by a host PC through an array of threshold comparators. The output consists of pulse patterns that can be generated either by a simulation program or in the HW itself. The system can be used as a selective distance/motion detector and can be employed in several applications involving target detection or obstacle avoidance.