Distance estimation with simple optical systems

Research project P 14697 Distance estimation with siple optical systems Karl KRAL 09.10.2000 Even though most of the factors or cues required by members of the animal kingdom for the visual estimation of distances have already been identified, the neural mechanisms involved are only very imperfectly understood. One reason for this is that it is technically extremely difficult to establish direct connections between visual stimulus situations, complex neural processing and behavioural responses. This difficult task is most likely to prove possible in the case of relatively simple visual systems, such as those of lower vertebrates and invertebrates. This has already been recognized in the field of robotics; in the design of intelligent mobile robots which need to be able to monitor distances actively (and adaptively) by means of visual sensors, engineers attempt to be guided primarily by relatively simple biological visual systems. Useful initial approaches also exist, for the development biological models based on the insect visual system. Of course, for this purpose, knowledge concerning the mechanisms for visual distance measurement in insects is required; however, such knowledge is still very fragmentary. Something is known concerning the use of motion cues in distance measurement, and this has already found technical application. However, stereo vision (the active binocular monitoring of distances) is also becoming increasingly important in the field of robotics. In this area, there is a lack of adequate comparative data pertaining to simple biological visual systems. This problem is to be addressed in the proposed research project; stereo vision is to be studied both in insects with high-resolution apposition eyes and in those with high (?)-resolution superposition eyes, and the ability of such insects to perform exact visual distance measurements to items of prey (as indicated by preliminary experiments) is to be investigated. Behavioural, optical, histological and physiological methods will be used.