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Vibrating Makes for Better Seeing: From the Fly's Micro-Eye Movements to Hyperacute Visual Sensors.

Viollet S - Front Bioeng Biotechnol (2014)

Bottom Line: Several robotic platforms have been endowed with artificial visual sensors performing periodic micro-scanning movements.Artificial eyes performing these active retinal micro-movements have some extremely interesting properties, such as hyperacuity and the ability to detect very slow movements (motion hyperacuity).The fundamental role of miniature eye movements still remains to be described in detail, but several studies on natural and artificial eyes have advanced considerably toward this goal.

View Article: PubMed Central - PubMed

Affiliation: Aix-Marseille University, CNRS, ISM UMR 7287 , Marseille , France.

ABSTRACT
Active vision means that visual perception not only depends closely on the subject's own movements, but that these movements actually contribute to the visual perceptual processes. Vertebrates' and invertebrates' eye movements are probably part of an active visual process, but their exact role still remains to be determined. In this paper, studies on the retinal micro-movements occurring in the compound eye of the fly are reviewed. Several authors have located and identified the muscles involved in these small retinal movements. Others have established that these retinal micro-movements occur in walking and flying flies, but their exact functional role still remains to be determined. Many robotic studies have been performed in which animals' (flies' and spiders') miniature eye movements have been modeled, simulated, and even implemented mechanically. Several robotic platforms have been endowed with artificial visual sensors performing periodic micro-scanning movements. Artificial eyes performing these active retinal micro-movements have some extremely interesting properties, such as hyperacuity and the ability to detect very slow movements (motion hyperacuity). The fundamental role of miniature eye movements still remains to be described in detail, but several studies on natural and artificial eyes have advanced considerably toward this goal.

No MeSH data available.


Related in: MedlinePlus

Three generations of twin-rotor robots equipped with a vibrating eye inspired by the micro-movements of the fly’s retina (see Section “Retinal Micro-Movements in the Fly’s Compound Eye: A Review”). All these sighted robots are endowed with hyperacuity, i.e., they are able to locate and smoothly track a moving target with a much greater accuracy than that imposed by limitations of the pixel pitch of their eyes. (A) The 100-g OSCAR robot with an eye composed of only 2 pixels, scanning back and forth at a frequency of 10 Hz with an amplitude of 9° (Viollet and Franceschini, 1999a,b, 2001). (B) The VODKA robot equipped with its scanning eye, on which periodic micro-scanning movements were imposed by means of a piezo bender translating the two photodiodes placed behind a fixed lens (Kerhuel et al., 2007, 2010, 2012). The VODKA robot was able to locate a contrasting feature with a 900 times greater accuracy than its static optical resolution (without any micro-movements of the eye). (C) The HyperRob robot equipped with the active version of the artificial curved compound eye called CurvACE (Floreano et al., 2013).
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Figure 5: Three generations of twin-rotor robots equipped with a vibrating eye inspired by the micro-movements of the fly’s retina (see Section “Retinal Micro-Movements in the Fly’s Compound Eye: A Review”). All these sighted robots are endowed with hyperacuity, i.e., they are able to locate and smoothly track a moving target with a much greater accuracy than that imposed by limitations of the pixel pitch of their eyes. (A) The 100-g OSCAR robot with an eye composed of only 2 pixels, scanning back and forth at a frequency of 10 Hz with an amplitude of 9° (Viollet and Franceschini, 1999a,b, 2001). (B) The VODKA robot equipped with its scanning eye, on which periodic micro-scanning movements were imposed by means of a piezo bender translating the two photodiodes placed behind a fixed lens (Kerhuel et al., 2007, 2010, 2012). The VODKA robot was able to locate a contrasting feature with a 900 times greater accuracy than its static optical resolution (without any micro-movements of the eye). (C) The HyperRob robot equipped with the active version of the artificial curved compound eye called CurvACE (Floreano et al., 2013).

Mentions: Many visual sensors based on active retinal micro-movements have been used for various purposes, such as enhancing edge detection (Ando, 1988; Prokopowicz and Cooper, 1995; Hongler et al., 2003) and improving obstacle avoidance (Mura and Shimoyama, 1998). However, few studies have focused so far on the use of retinal vibrations to enhance visual acuity. Visual scanning at a variable angular speed was previously used to enhance the resolution by a factor of 40 in an edge-locating task (Viollet and Franceschini, 1999a,b), and more recently by a factor of 70 (Viollet and Franceschini, 2010). A pulsed-scanning mode was found to help a mobile robot detect the simple presence of edges in its visual field (Mura and Shimoyama, 1998). A circular micro-scanning mode was developed to improve the spatial resolution by transforming spatial information into temporal information (Landolt and Mitros, 2001). This same mode was also used to obtain line or edge operators by correlating a modulating signal with the output signals emitted by a 2-D imager (Ando, 1988). A recent study (Kerhuel et al., 2012) has focused on the processing of the amplitude of the photodector’s output signals. By applying sinusoidal micro-scanning movements to a retina composed of only 2 pixels, it was established that the ratio between the difference and the sum of the differentiated photodetector signals can lead to an outstanding degree of hyperacuity, which was 900 times higher than the interreceptor angle (2.87°). Figure 5 shows three generations of bio-inspired sighted aerial robotic platforms equipped with either an eye with a vibrating retina comprising only two pixels (Figures 5A,B) or an artificial compound eye (Floreano et al., 2013) subjected to a periodic micro-scanning movement. All these robots are endowed with hyperacuity, and they can lock their gaze onto a moving contrasting target (bars or edges) and track it smoothly by automatically controlling the orientation of their eye (in the case of the robots shown in Figures 5B,C) and thus, the orientation of their body (their heading). Table 1 summarizes the features of the different scanning sensors inspired by the fly’s retinal micro-movements and the benefits of the visual scanning in terms of optical resolution enhancement.


Vibrating Makes for Better Seeing: From the Fly's Micro-Eye Movements to Hyperacute Visual Sensors.

Viollet S - Front Bioeng Biotechnol (2014)

Three generations of twin-rotor robots equipped with a vibrating eye inspired by the micro-movements of the fly’s retina (see Section “Retinal Micro-Movements in the Fly’s Compound Eye: A Review”). All these sighted robots are endowed with hyperacuity, i.e., they are able to locate and smoothly track a moving target with a much greater accuracy than that imposed by limitations of the pixel pitch of their eyes. (A) The 100-g OSCAR robot with an eye composed of only 2 pixels, scanning back and forth at a frequency of 10 Hz with an amplitude of 9° (Viollet and Franceschini, 1999a,b, 2001). (B) The VODKA robot equipped with its scanning eye, on which periodic micro-scanning movements were imposed by means of a piezo bender translating the two photodiodes placed behind a fixed lens (Kerhuel et al., 2007, 2010, 2012). The VODKA robot was able to locate a contrasting feature with a 900 times greater accuracy than its static optical resolution (without any micro-movements of the eye). (C) The HyperRob robot equipped with the active version of the artificial curved compound eye called CurvACE (Floreano et al., 2013).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4126468&req=5

Figure 5: Three generations of twin-rotor robots equipped with a vibrating eye inspired by the micro-movements of the fly’s retina (see Section “Retinal Micro-Movements in the Fly’s Compound Eye: A Review”). All these sighted robots are endowed with hyperacuity, i.e., they are able to locate and smoothly track a moving target with a much greater accuracy than that imposed by limitations of the pixel pitch of their eyes. (A) The 100-g OSCAR robot with an eye composed of only 2 pixels, scanning back and forth at a frequency of 10 Hz with an amplitude of 9° (Viollet and Franceschini, 1999a,b, 2001). (B) The VODKA robot equipped with its scanning eye, on which periodic micro-scanning movements were imposed by means of a piezo bender translating the two photodiodes placed behind a fixed lens (Kerhuel et al., 2007, 2010, 2012). The VODKA robot was able to locate a contrasting feature with a 900 times greater accuracy than its static optical resolution (without any micro-movements of the eye). (C) The HyperRob robot equipped with the active version of the artificial curved compound eye called CurvACE (Floreano et al., 2013).
Mentions: Many visual sensors based on active retinal micro-movements have been used for various purposes, such as enhancing edge detection (Ando, 1988; Prokopowicz and Cooper, 1995; Hongler et al., 2003) and improving obstacle avoidance (Mura and Shimoyama, 1998). However, few studies have focused so far on the use of retinal vibrations to enhance visual acuity. Visual scanning at a variable angular speed was previously used to enhance the resolution by a factor of 40 in an edge-locating task (Viollet and Franceschini, 1999a,b), and more recently by a factor of 70 (Viollet and Franceschini, 2010). A pulsed-scanning mode was found to help a mobile robot detect the simple presence of edges in its visual field (Mura and Shimoyama, 1998). A circular micro-scanning mode was developed to improve the spatial resolution by transforming spatial information into temporal information (Landolt and Mitros, 2001). This same mode was also used to obtain line or edge operators by correlating a modulating signal with the output signals emitted by a 2-D imager (Ando, 1988). A recent study (Kerhuel et al., 2012) has focused on the processing of the amplitude of the photodector’s output signals. By applying sinusoidal micro-scanning movements to a retina composed of only 2 pixels, it was established that the ratio between the difference and the sum of the differentiated photodetector signals can lead to an outstanding degree of hyperacuity, which was 900 times higher than the interreceptor angle (2.87°). Figure 5 shows three generations of bio-inspired sighted aerial robotic platforms equipped with either an eye with a vibrating retina comprising only two pixels (Figures 5A,B) or an artificial compound eye (Floreano et al., 2013) subjected to a periodic micro-scanning movement. All these robots are endowed with hyperacuity, and they can lock their gaze onto a moving contrasting target (bars or edges) and track it smoothly by automatically controlling the orientation of their eye (in the case of the robots shown in Figures 5B,C) and thus, the orientation of their body (their heading). Table 1 summarizes the features of the different scanning sensors inspired by the fly’s retinal micro-movements and the benefits of the visual scanning in terms of optical resolution enhancement.

Bottom Line: Several robotic platforms have been endowed with artificial visual sensors performing periodic micro-scanning movements.Artificial eyes performing these active retinal micro-movements have some extremely interesting properties, such as hyperacuity and the ability to detect very slow movements (motion hyperacuity).The fundamental role of miniature eye movements still remains to be described in detail, but several studies on natural and artificial eyes have advanced considerably toward this goal.

View Article: PubMed Central - PubMed

Affiliation: Aix-Marseille University, CNRS, ISM UMR 7287 , Marseille , France.

ABSTRACT
Active vision means that visual perception not only depends closely on the subject's own movements, but that these movements actually contribute to the visual perceptual processes. Vertebrates' and invertebrates' eye movements are probably part of an active visual process, but their exact role still remains to be determined. In this paper, studies on the retinal micro-movements occurring in the compound eye of the fly are reviewed. Several authors have located and identified the muscles involved in these small retinal movements. Others have established that these retinal micro-movements occur in walking and flying flies, but their exact functional role still remains to be determined. Many robotic studies have been performed in which animals' (flies' and spiders') miniature eye movements have been modeled, simulated, and even implemented mechanically. Several robotic platforms have been endowed with artificial visual sensors performing periodic micro-scanning movements. Artificial eyes performing these active retinal micro-movements have some extremely interesting properties, such as hyperacuity and the ability to detect very slow movements (motion hyperacuity). The fundamental role of miniature eye movements still remains to be described in detail, but several studies on natural and artificial eyes have advanced considerably toward this goal.

No MeSH data available.


Related in: MedlinePlus