Optic flow sensors for robots: elementary motion detectors based on FPGA

One recent trend in robotic aircraft has been the development of embedded sensors inspired by biology, in particular optic flow sensors for use in collision avoidance, stabilization and other visual guidance tasks. Optic flow is determined here by elementary motion detectors (EMDs) whose principle is based on the results of an electrophysiological analysis of visual neurons in the housefly. To achieve small embedded optical flow sensors, we have applied a top-down methodology to integrate several EMDs in a small field programmable gate array (FPGA) that is driven by an array of photoreceptors.