Analog VLSI Implementation of Wide-field Integration Methods

Abstract

In this paper a novel integrated, single-chip solution for autonomous navigation inspired by the computations in the insect visuomotor system is proposed. A generalization of the theory of wide field integration (WFI) is presented which supports the use of sensors with a limited field of view, and the system concept is validated based on experiments using a prototype single-chip WFI sensor. The VLSI design implements (1) an array of Elementary Motion Detectors (EMDs) to derive local estimates of optic flow, (2) a novel mismatch compensation approach to handle dissimilarities in local motion detector units, and (3) on-chip programmable optic flow pattern weighting (Wide-Field Integration) to extract relative speed and proximity with respect to the surrounding environment. Computations are performed in the analog domain and in parallel, providing outputs at 1 kHz while consuming only 42.6 μW of power. The resulting sensor is integrated with a ground vehicle and navigation of corridor-like environments is demonstrated.