Visual Odometry and Low Optic Flow Measurement by Means of a Vibrating Artificial Compound Eye

• Published in: Biomimetic and Biohybrid Systems Vol. 9222; pp. 153 - 163
• Main Authors: Colonnier, Fabien, Manecy, Augustin, Juston, Raphaël, Viollet, Stéphane
• Format: Book Chapter
• Language: English
• Published: Switzerland Springer International Publishing AG 2015; Springer International Publishing
• Series: Lecture Notes in Computer Science
• Subjects: Artificial intelligence; Computer science; Computer vision; Eye micro-movements; Hyperacuity; Insect vision; Robotics
• ISBN: 3319229788; 9783319229782
• ISSN: 0302-9743; 1611-3349
• DOI: 10.1007/978-3-319-22979-9_16

In this study, a tiny artificial compound eye (diameter 15mm) named CurvACE (which stands for Curved Artificial Compound Eye), was endowed with hyperacuity, based on an active visual process inspired by the retinal micro-movements occurring in the fly’s compound eye. A periodic (1-D, 50-Hz) micro-scanning movement with a range of a few degrees (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$5^\circ $$\end{document}) enables the active CurvACE to locate contrasting objects with a 40-fold greater accuracy which was restricted by the narrow interommatidial angle of about \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$4.2^\circ $$\end{document}. This local hyperacuity was extended to a large number of adjacent ommatidia in a novel visual processing algorithm, which merges the output signals of the local processing units running in parallel on a tiny, cheap micro-controller requiring very few computational resources. Tests performed in a textured (indoor) or natural (outdoor) environment showed that the active compound eye serves as a contactless angular position sensing device, which is able to assess its angular position relative to the visual environment. As a consequence, the vibrating compound eye is able to measure very low rotational optic flow up to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ 20^\circ /s $$\end{document} and perform a short range odometry knowing the altitude, which are two tasks of great interest for robotic applications.