scholarly journals Optic Flow Based Visual Guidance: From Flying Insects to Miniature Aerial Vehicles

10.5772/6491 ◽  
2009 ◽  
Author(s):  
Nicolas Franceschini ◽  
Franck Ruffier ◽  
Julien Serres ◽  
Stephane Viollet
Keyword(s):  
Optic Flow ◽  
Visual Guidance ◽  
Flying Insects ◽  
Aerial Vehicles

Simulated Optic Flow and Extrastriate Cortex. I. Optic Flow Versus Texture

1997 ◽  
Vol 77 (2) ◽  
pp. 554-561 ◽  
Author(s):  
Jong-Nam Kim ◽  
Kathleen Mulligan ◽  
Helen Sherk
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Optic Flow ◽  
Visual Experience ◽  
Extrastriate Cortex ◽  
Gray Level ◽  
Visual Guidance ◽  
Forward Motion ◽  
Cell Responses ◽  
Single Origin

Kim, Jong-Nam, Kathleen Mulligan, and Helen Sherk. Simulated optic flow and extrastriate cortex. I. Optic flow versus texture. J. Neurophysiol. 77: 554–561, 1997. A locomoting observer sees a very different visual scene than an observer at rest: images throughout the visual field accelerate and expand, and they follow approximately radial outward paths from a single origin. This so-called optic flow field is presumably used for visual guidance, and it has been suggested that particular areas of visual cortex are specialized for the analysis of optic flow. In the cat, the lateral suprasylvian visual area (LS) is a likely candidate. To test the hypothesis that LS is specialized for analysis of optic flow fields, we recorded cell responses to optic flow displays. Stimulus movies simulated the experience of a cat trotting slowly across an endless plain covered with small balls. In different simulations we varied the size of balls, their organization (randomly or regularly dispersed), and their color (all one gray level, or multiple shades of gray). For each optic flow movie, a “texture” movie composed of the same elements but lacking optic flow cues was tested. In anesthetized cats, >500 neurons in LS were studied with a variety of movies. Most (70%) of 454 visually responsive cells responded to optic flow movies. Visually responsive cells generally preferred optic flow to texture movies (69% of those responsive to any movie). The direction in which a movie was shown (forward or reverse) was also an important factor. Most cells (68%) strongly preferred forward motion, which corresponded to visual experience during locomotion.

scholarly journals Budgerigar flight in a varying environment: flight at distinct speeds?

2016 ◽  
Vol 12 (6) ◽  
pp. 20160221 ◽  
Author(s):  
Ingo Schiffner ◽  
Mandyam V. Srinivasan
Keyword(s):  
Optic Flow ◽  
Energy Efficient ◽  
High Speed ◽  
Open Spaces ◽  
Low Speed ◽  
Cluttered Environment ◽  
Changing Environments ◽  
Flying Insects ◽  
Varying Environments ◽  
Dual Speed

How do flying birds respond to changing environments? The behaviour of budgerigars, Melopsittacus undulatus , was filmed as they flew through a tapered tunnel. Unlike flying insects—which vary their speed progressively and continuously by holding constant the optic flow induced by the walls—the birds showed a tendency to fly at only two distinct, fixed speeds. They switched between a high speed in the wider section of the tunnel, and a low speed in the narrower section. The transition between the two speeds was abrupt, and anticipatory. The high speed was close to the energy-efficient, outdoor cruising speed for these birds, while the low speed was approximately half this value. This is the first observation of the existence of two distinct, preferred flight speeds in birds. A dual-speed flight strategy may be beneficial for birds that fly in varying environments, with the high speed set at an energy-efficient value for flight through open spaces, and the low speed suited to safe manoeuvring in a cluttered environment. The constancy of flight speed within each regime enables the distances of obstacles and landmarks to be directly calibrated in terms of optic flow, thus facilitating simple and efficient guidance of flight through changing environments.

scholarly journals To keep on track during flight, fruitflies discount the skyward view

2014 ◽  
Vol 10 (2) ◽  
pp. 20131103 ◽  
Author(s):  
Chantell Mazo ◽  
Jamie C. Theobald
Keyword(s):  
Flow Field ◽  
Rotational Motion ◽  
Optic Flow ◽  
Translational Motion ◽  
Visual Fields ◽  
Flow Fields ◽  
Motion Pattern ◽  
Flying Insects ◽  
Visual Areas ◽  
Pattern Of Motion

When small flying insects go off their intended course, they use the resulting pattern of motion on their eye, or optic flow, to guide corrective steering. A change in heading generates a unique, rotational motion pattern and a change in position generates a translational motion pattern, and each produces corrective responses in the wingbeats. Any image in the flow field can signal rotation, but owing to parallax, only the images of nearby objects can signal translation. Insects that fly near the ground might therefore respond more strongly to translational optic flow that occurs beneath them, as the nearby ground will produce strong optic flow. In these experiments, rigidly tethered fruitflies steered in response to computer-generated flow fields. When correcting for unintended rotations, flies weight the motion in their upper and lower visual fields equally. However, when correcting for unintended translations, flies weight the motion in the lower visual fields more strongly. These results are consistent with the interpretation that fruitflies stabilize by attending to visual areas likely to contain the strongest signals during natural flight conditions.

scholarly journals Optic flow informs distance but not profitability for honeybees

2009 ◽  
Vol 277 (1685) ◽  
pp. 1241-1245 ◽  
Author(s):  
Sharoni Shafir ◽  
Andrew B. Barron
Keyword(s):  
Apis Mellifera ◽  
Optic Flow ◽  
Processing System ◽  
Foraging Efficiency ◽  
Dual Processing ◽  
Energetic Costs ◽  
Flying Insects ◽  
Dance Communication ◽  
Flow Information ◽  
Optic Flow Information

How do flying insects monitor foraging efficiency? Honeybees ( Apis mellifera ) use optic flow information as an odometer to estimate distance travelled, but here we tested whether optic flow informs estimation of foraging costs also. Bees were trained to feeders in flight tunnels such that bees experienced the greatest optic flow en route to the feeder closest to the hive. Analyses of dance communication showed that, as expected, bees indicated the close feeder as being further, but they also indicated this feeder as the more profitable, and preferentially visited this feeder when given a choice. We show that honeybee estimates of foraging cost are not reliant on optic flow information. Rather, bees can assess distance and profitability independently and signal these aspects as separate elements of their dances. The optic flow signal is sensitive to the nature of the environment travelled by the bee, and is therefore not a good index of flight energetic costs, but it provides a good indication of distance travelled for purpose of navigation and communication, as long as the dancer and recruit travel similar routes. This study suggests an adaptive dual processing system in honeybees for communicating and navigating distance flown and for evaluating its energetic costs.

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