Small Brains, Smart Machines: From Fly Vision to Robot Vision and Back Again

Abstract

Neurobiological and neuroethological findings on insects can be used to design and construct small robots controlling their navigation on the basis of bio-inspired visual strategies and circuits. Animals' visual guidance is partly mediated by motion-sensitive neurons, which are responsible for gauging the optic flow. Although neurons of this kind were discovered in vertebrates' and invertebrates' visual systems more than 50 years ago, the principles and neural mechanisms involved have not yet been completely elucidated. Here, first, I propose to outline some of the findings we made during the last few decades by performing electrophysiological recordings on identified neurons in the housefly's eye while applying optical stimulation to identified photoreceptors. Whereas these findings shed light on the inner processing structure of an elementary motion detector (EMD), recent studies in which the latest genetic and neuroanatomical methods were applied to the fruitfly's visual system have identified some of the neurons in the visual chain which are possibly involved in the neural circuitry underlying a given EMD. Then, I will describe some of the proof-of-concept robots that we have developed on the basis of our biological findings. The 100-g robot OCTAVE, for example, is able to avoid the ground, react to wind, and land autonomously on a flat terrain without ever having to measure any state variables such as distances or speeds. The 100-g robots OSCAR 1 and OSCAR 2 inspired by the microscanner we discovered in the housefly's eye are able to stabilize their body using mainly visual means and track a moving edge with hyperacuity. These robots react to the optic flow, which is sensed by miniature optic flow sensors inspired by the housefly's EMDs. Constructing a “biorobot” gives us a unique opportunity of checking the soundness and robustness of a principle that is initially thought to be understood by bringing it face to face with the real physical world. Bio-inspired robotics not only help neurobiologists and neuroethologists to identify and investigate worthwhile problems in animals' sensory-motor systems, but they also provide engineers with ideas for developing novel devices and machines with promising future applications, in the field of smart autonomous vehicles and microvehicles, for example.