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A universal strategy for visually guided landing.

  • Emily Baird
  • Norbert Boeddeker
  • Michael R Ibbotson
  • Mandyam V Srinivasan
Publishing year: 2013
Language: English
Pages: 18686-18691
Publication/Series: Proceedings of the National Academy of Sciences
Volume: 110
Issue: 46
Document type: Journal article
Publisher: National Acad Sciences

Abstract english

Landing is a challenging aspect of flight because, to land safely, speed must be decreased to a value close to zero at touchdown. The mechanisms by which animals achieve this remain unclear. When landing on horizontal surfaces, honey bees control their speed by holding constant the rate of front-to-back image motion (optic flow) generated by the surface as they reduce altitude. As inclination increases, however, this simple pattern of optic flow becomes increasingly complex. How do honey bees control speed when landing on surfaces that have different orientations? To answer this, we analyze the trajectories of honey bees landing on a vertical surface that produces various patterns of motion. We find that landing honey bees control their speed by holding the rate of expansion of the image constant. We then test and confirm this hypothesis rigorously by analyzing landings when the apparent rate of expansion generated by the surface is manipulated artificially. This strategy ensures that speed is reduced, gradually and automatically, as the surface is approached. We then develop a mathematical model of this strategy and show that it can effectively be used to guide smooth landings on surfaces of any orientation, including horizontal surfaces. This biological strategy for guiding landings does not require knowledge about either the distance to the surface or the speed at which it is approached. The simplicity and generality of this landing strategy suggests that it is likely to be exploited by other flying animals and makes it ideal for implementation in the guidance systems of flying robots.


  • Zoology
  • vision
  • flight control
  • insect
  • three-dimensional surface


  • ISSN: 1091-6490
Emily Baird
E-mail: emily [dot] baird [at] biol [dot] lu [dot] se


Functional zoology

+46 46 222 96 18

+46 72 700 55 55



Research group

Lund Vision Group


Doctoral students and postdocs

PhD Students, main supervisor

Pierre Tichit

PhD Students, assistant supervisor

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