Integrated polarization analyzing CMOS Image sensor for autonomus navigation using polarized light

Abstract

Navigation is important both for insects to perform living tasks and robots to perform assigned tasks. We propose a CMOS image sensor for autonomous agent navigation which mimicks the navigational patterns of insects using the variations in the degree of skylight polarization. The polarization pattern of the skylight varies in a systematic way both in the plane (e-vector) and the degree of polarization according to the sun's position. The proposed CMOS image sensor is able to sense polarization information in real time using a metallic wire grid micro-polarizer oriented in various directions on top of the pixel. The degree of polarization is computed from the sensed polarization information, the variations of which can be used as a compass. The image sensor consist of an array of 128×128 pixels, occupies an area of 5×4mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and it has been designed and fabricated in a 180nm CMOS process.