Steering by Gazing: An Efficient Biomimetic Strategy for the Visual Stabilization of Micro-Air Vehicles

Flying insects and birds are able to navigate swiftly in unknown environments with very few computational resources. They are not guided via radio links with any ground stations and perform all the required calculations on-board. The ability to stabilize the gaze is the key to an efficient visual guidance system, as it reduces the computational burden associated with visuo-motor processing. Smooth pursuit by the eye is another requisite: the ability to fix the gaze on a given moving feature significantly reduces the neural resources required to extract relevant visual information from the environment. Although their brains are so small and their eyes have so few pixels, flying insects can perform some extraordinary behavioral feats, such as navigating in 3-D environments, avoiding stationary and moving obstacles, hovering, tracking mates and intruders, and intercepting prey, relying solely on visual guidance. Gaze stabilization is a difficult task because the eye control system must compensate both quickly and accurately for any sudden, untoward disturbances caused by the vagaries of the supporting head or body. In the freely flying housefly, active gaze stabilization mechanisms prevent the incoming visual information from being affected by disturbances such as vibrations or body jerks [1][2]. The freely flying sandwasp, for instance, keeps its gaze amazingly stable despite the large thorax rolls it performs [3]. The stringent requirements involved in visual stabilization may explain why eye movements are among the fastest and most accurate of all the movements in the repertory of the animal kingdom.