An insect-inspired omnidirectional vision system including UV-sensitivity and polarisation

A major difference between insect vision and that of humans or standard computer vision systems is that insects are sensitive to the polarisation pattern of skylight, and also to the near-UV range of the electromagnetic spectrum. In this paper, we describe a bio-inspired imaging system that allows us to assess to what extent these features could potentially be used for autonomous robot navigation. We first establish that a low-resolution omnidirectional system incorporating a near-UV camera and a linear polariser - a simulacrum of the dorsal rim area of the insect compound eye - can resolve the clear sky natural polarisation pattern with sufficient accuracy to allow its use as a navigational tool. We then extend the bio-mimicry by incorporating an additional RGB camera, allowing us to utilise the full range of the insect´s visual spectrum. This enables us to capture and investigate the visual cues insects are employing for flight control and navigation, and paves the way for incorporating a similar system in an autonomous mobile robot. Additionally, we present a robust method for estimating sun position based on the polarisation pattern and thus confirm the utility of the system as a sky compass.