Flies in Flight Provide Insight for Aircraft Altitude Control Research Published Sept. 26, 2011 By Maria Callier Office of Scientific Research ARLINGTON, Virginia -- AFRL-funded Caltech researchers are studying flying insects for inspiration and information on altitude control, hoping to transfer that intelligence into technology for a variety of Air Force aircraft. The study is focusing on how flies use visual information to guide flight in natural environments. The scientists have found that, counter to earlier studies suggesting insects adjust their height by measuring the motion beneath them, flies in fact follow horizontal edges of objects to regulate altitude. Remarkably, this edge-following behavior is very similar to a rule they use for steering left and right and always turning toward vertical edges. The scientists designed a virtual reality environment for their flying subjects which they found could regulate their altitude by enabling them to fly at the height of nearby horizontal visuals, such as the tops of rocks and vegetation. "We developed a 3D fly-tracking system which was our most significant technical challenge: localizing a fly in 3D nearly instantaneously," said Caltech's Dr. Andrew Straw. "Next, we developed visual stimulus software capable of making use of this information to project virtual edges and textured floors in which we could modify the fly's sensory-motor feedback mechanism." The 3D fly-tracking system is significant because it will allow a rapid characterization of other fly behaviors with unprecedented levels of visual stimulus control. Ultimately the scientists would like to build models of fly flight that can accurately predict behavior based on their sensory input and internal states. In the next phase, the scientists will study more sophisticated flight behaviors, investigating whether the fly creates a long-lasting neural representation of its visual surroundings or if flight is controlled by fast-acting reflexes.