Visual Motion Computation in Analog VLSI Using Pulses

Abstract

The real time computation of motion from real images using a single chip with integrated sensors is a hard problem. We present two analog VLSI schemes that use pulse domain neuromorphic circuits to compute motion. Pulses of variable width, rather than graded potentials, represent a natural medium for evaluating temporal relationships. Both algorithms measure speed by timing a moving edge in the image. Our first model is inspired by Reichardt's algorithm in the fly and yields a non-monotonic response vs. velocity curve. We present data from a chip that implements this model. Our second algorithm yields a monotonic response vs. velocity curve and is currently being translated into silicon. 1 Introduction Analog VLSI chips for the real time computation of visual motion have been the focus of much active research because of their importance as sensors for robotic applications. Correlation schemes such as those described in (Delbruck, 1993) have been found to be more robust than gradient s...