One of the fundamental abilities required in autonomous agents is homing. Natural agents—for instance, desert ants—solve the homing problem mainly by using path integration within an egocentric frame of reference. When employing such a mechanism, compass information for determining direction is necessary, and the precision of the compass will have a crucial effect on the precision of homing. For deriving compass information, certain insects use the pattern of polarized light in the sky that arises due to scattering of sunlight in the atmosphere (polarized light compass). The analysis of skylight polarization is mediated by specialized photoreceptors and neurons in the visual system. Inspired by the insect's polarized light compass, we have constructed a polarization compass that was employed successfully on the mobile robot Sahabot. Three models for extracting compass information from the polarization pattern of the sky were tested. In this article, we describe the navigation system and report results of experiments performed with the Sahabot in one of the natural habitats of the desert ant Cataglyphis in North Africa.
Bernard, G.D., & Wehner, R. (1977). Functional similarities between polarization vision and color vision. Vision Research, 17, 1019-1028.
2.
Brooks, R.A. (1991). Intelligence without representation. Artificial Intelligence, 47, 139-160.
3.
Brunner, D., & Labhart, T. (1987). Behavioural evidence for polarization vision in crickets. Physiological Entomology, 12, 1-10.
4.
Burghause, F.M.H.R. (1979). Die strukturelle Spezialisierung des dorsalen Augenteils der Grillen (Orthoptera, Grylloidea). Zoologische jahrbücher: Abteilung für allgemeine Zoologie und Physiologie der Tiere, 83, 502-525.
5.
Duelli, P., & Wehner, R. (1973). The spectral sensitivity of polarized light orientation in Cataglyphis bicolor (Formicidae, Hymenoptera). Journal of Comparative Physiology, 86, 37-53.
6.
Edelman, G.M., Reeke, G.N., Gall, W.E., Tononi, G., & Williams, D. (1992). Synthetic neural modeling applied to a real-world artifact. Proceedings of the National Academy of Sciences of the United States of America,89, 7267—7271.
7.
Edrich, W., & von Helversen, O. (1987). Polarized light orientation in honey bees: Is time a component in sampling? Biological Cybernetics, 56, 89-96.
8.
Fent, K. (1986). Polarized skylight orientation in the desert ant Cataglyphis. Journal of Comparative Physiology [A], 158, 145-150.
9.
Ferrell, C. (1993). Robust agent control of an autonomous robot with many sensors and actuators (Tech. Rep.). Cambridge, MA : Artificial Intelligence Laboratory, MIT.
10.
Franceschini, N., Pichon, J.M., & Blanes, C. (1992). From insect vision to robot vision. Philosophical Transactions of the Royal Society of London [A], 337, 283-294.
11.
Hardie, R.C. (1984). Properties of photoreceptors R7 and R8 in dorsal marginal ommatidia in the compound eyes of Musca and Calliphora. Journal of Comparative Physiology [A], 154, 157-165.
12.
Hartmann, G. & Wehner, R. (1995). The ant's path integration system: A neural architecture . Biological Cybernetics, 73(6), 483-493.
13.
Herrling, P.L. (1976). Regional distribution of three ultrastructural retinula types in the retina of Cataglyphis bicolor Fabr. (Formicidae, Hymenoptera) . Cell and Tissue Research, 169, 247-266.
14.
Kirschfeld, K. (1972). Die notwendige Anzahl von Rezeptoren zur Bestimmung der Richtung des elektrischen Vektors linear polarisierten Lichtes. Zeitschrift für Naturforschung, 27b, 578-579.
15.
Labhart, T. (1980). Specialized photoreceptors at the dorsal rim of the honeybee's compound eye: Polarizational and angular sensitivity. Journal of Comparative Physiology, 141, 19-30.
16.
Labhart, T. (1986). The electrophysiology of photoreceptors in different eye regions of the desert ant, Cataglyphis bicolor. Journal of Comparative Physiology [A], 158, 1-7.
17.
Labhart, T. (1988). Polarization-opponent interneurons in the insect visual system. Nature, 331, 435—437.
18.
Labhart, T. (1996). How polarization-sensitive interneurones perform at low degrees of polarization. Journal of Experimental Biolology , 199, 1467-1475.
19.
Labhart, T., Hodel, B., & Valenzuela, I. (1984). The physiology of the cricket's compound eye with particular reference to the anatomically specialized dorsal rim area. Journal of Comparative Physiology [A], 155, 289-296.
20.
Labhart, T., Meyer, E.P., & Schenker, L. (1992). Specialized ommatidia for polarization vision in the compound eye of cockchafers, Melolontha melolontha (Coleoptera, Scarabaeidae). Cell and Tissue Research, 268, 419-429.
21.
Labhart, T., & Petzold, J. (1993). Processing of polarized light information in the visual system of crickets. In K. Wiese, F. G. Gribakin, A. V Popov , & G. Renninger (Eds.), Sensory systems of arthropods. Basel: Birkhäuser Verlag.
22.
Lambrinos, D. (1995). Navigating with an adaptive light compass. In J. G. Carbonell & J. Sickmann (Eds.), Proceedings of the Third European Conference on Artificial Life (Granada, Spain). Berlin: Springer.
23.
Maes, P., & Brooks, R.A. (1990). Learning to co-ordinate behaviours. In Proceedings of the Eighth National Conference on Artificial Intelligence , Vol. 2. Cambridge, MA: AAAI Press/MIT Press.
24.
Meinecke, C.C. (1981). The fine structure of the compound eye of the African armyworm moth, Spodoptera exempta walk (Lepidoptera, Noctuidae). Cell and Tissue Research, 216, 333-347.
25.
Meyer, E.P., & Labhart, T. (1993). Morphological specializations of dorsal rim ommatidia in the compound eye of dragonflies and damselflies (Odonata). Cell and Tissue Research, 272, 17-22.
26.
Mittelstaedt, H. (1985). Analytical cybernetics of spider navigation. In F. G. Barth (Ed.), Neurobiology of arachnids. Berlin: Springer.
27.
Müller, M., & Wehner, R. (1988). Path integration in desert ants, Cataglyphis fortis . Proceedings of the National Academy of Sciences of the United States of America, 85, 5287—5290.
28.
Petzold, J., & Labhart, T. (1993). Polarization-opponent interneurons of crickets: Absolute threshold, visual field properties and response to low degrees of polarization. In N. Elsner & M. Heisenberg (Eds.), Proceedings of the Neurobiology Conference of Göttingen, Vol. 21. Stuttgart: Thieme Verlag.
29.
Rossel, S. (1993). Navigation by bees using polarized skylight. Comparative Biochemistry and Physiology [A], 104, 695-708.
30.
Rossel, S., & Wehner, R. (1986). Polarization vision in bees. Nature, 323, 128—131.
31.
Schinz, R. (1975). Structural specialization in the dorsal retina of the bee, Apis mellifera. Cell and Tissue Research, 162, 23-34.
32.
von Frisch, K. (1949). Die Polarisation des Himmelslichtes als orientierender Faktor bei den Tänzen der Bienen. Experientia, 5, 142-148.
33.
von Philipsborn, A., & Labhart, T. (1990). A behavioural study of polarization vision in the fly, Musca domestica. Journal of Comparative Physiology [A], 167, 737-743.
34.
Webb, B., & Hallam, J. (1996). How to attract females: further robotic experiments in cricket phonotaxis. In P Maes, M. J. Matarić, J.-A. Meyer, J. Pollack, & S. Wilson (Eds.), Proceedings of the Fourth International Conference on Simulation of Adaptive Behavior . Cambridge, MA: MIT Press.
35.
Wehner, R. (1982). Himmelsnavigation bei Insekten. Neurophysiologie und Verhalten. Neujahrsblatt der Naturforschenden Gesellschaft Zürich, 184, 1—132.
36.
Wehner, R. (1983). Taxonomie, Funktionsmorphologie und Zoogeographie der saharischen Wüstenameise Cataglyphis fortis stat. nov. Senckenbergiana Biologica, 64, 89—132.
37.
Wehner, R. (1987). Spatial organization of foraging behavior in individually searching desert ants, Cataglyphis (Sahara Desert) and Ocymyrmex (Namib Desert) . In J. M. Pasteels & J. L. Denebourg (Eds.), From individual to collective behavior in social insects. Basel: Birkhäuser Verlag.
38.
Wehner, R. (1994). The polarization-vision project: Championing organismic biology. In K. Schildberger and N. Elsner (Eds.), Neural basis of behavioural adaptations. Stuttgart: Gustav Fischer Verlag.
39.
Wehner, R., & Duelli, P. (1971). The spatial orientation of desert ants, Cataglyphis bicolor, before sunrise and after sunset. Experientia, 27, 1364-1366.
40.
Wehner, R., & Lanfranconi, B. (1981). What do the ants know about the rotation of the sky? Nature, 293, 731-773.
41.
Wehner, R., Lehrer, M., & Harvey, W R. (Eds.) (1996). Navigation: Migration and homing. journal of Experimental Biology, 199, 1-126.
42.
Wehner, R., & Wehner, S. (1986). Path integration in desert ants. Approaching a long-standing puzzle in insect navigation. Monitore Zoologico Italiano (New Series), 20,309-331.
Wunderer, H., & Smola, U. (1982). Fine structure of ommatidia at the dorsal eye margin of Calliphora erythrocephala Meigen (Diptera: Calliphoridae): An eye region specialised for the detection of polarized light. International Journal of Insect Morphology and Embryology, 11, 25-38.
