Researchers at the University of Cincinnati have developed a flapping-wing drone that can locate and hover around a moving light source like a moth drawn to a flame.<\/p>\n
The project, led by UC College of Engineering and Applied Science Assistant Professor Sameh Eisa, could pave the way for small, efficient drones used in covert surveillance.<\/p>\n
Eisa and his aerospace engineering students say the secret lies in mimicking insect flight. \u201cThe reason we\u2019re interested is size. It\u2019s a more optimal design. These small robots would have to fly like a moth,\u201d Eisa said.<\/p>\n
Moths and other hovering insects can maintain their position midair or even fly backward. They instinctively adjust to wind and obstacles with precision.<\/p>\n
Eisa\u2019s drone does the same, making constant fine adjustments to maintain distance and orientation from a light, even when that light moves.<\/p>\n
Eisa\u2019s lab, the Modeling, Dynamics and Control Lab, focuses on animal-inspired engineering. In earlier research, his team studied drones that could use dynamic soaring like albatrosses to fly longer distances efficiently.<\/p>\n
The new mothlike drone takes inspiration from insects\u2019 agile hovering, which Eisa and doctoral student Ahmed Elgohary describe using a mathematical framework known as extremum-seeking feedback.<\/p>\n
In their study, the researchers propose that hovering insects use similar natural feedback systems.<\/p>\n
\u201cOur simulations show that extremum-seeking control can naturally reproduce the stable hovering behavior seen in insects, without AI or complex models,\u201d said Elgohary, the study\u2019s lead author.<\/p>\n
He added that the system relies on \u201ca simple feedback, model-free and real-time principle\u201d that may explain how small creatures fly so nimbly with limited brainpower.<\/p>\n
Real-time control without AI<\/p>\n
Unlike traditional drones that rely on GPS or artificial intelligence, this flapper drone adjusts its flight in real time by constantly measuring its performance.<\/p>\n
The system optimizes for a target, in this case light, through continuous feedback.<\/p>\n
Each wing flaps independently to control roll, pitch, and yaw. To the naked eye, the fast wingbeats appear as a blur, similar to a hummingbird\u2019s wings.<\/p>\n
The drone\u2019s feedback loop allows it to hover steadily, even replicating the subtle sway seen in moths, bumblebees, dragonflies, hoverflies, craneflies, and hummingbirds.<\/p>\n
Elgohary and UC graduate student Rohan Palanikumar demonstrated the drone in Eisa\u2019s flight lab, a netted space that protects both the machine and its operators.<\/p>\n
The four-winged drone, made from wire and fabric, can lift off and hold its position using the extremum-seeking system. Manual control, Elgohary said, is much harder and less stable.<\/p>\n
The wobble observed during flight isn\u2019t a flaw. It\u2019s part of the process. Those small oscillations help the drone assess performance and make micro-adjustments for stability and direction.<\/p>\n
Lessons from nature\u2019s engineers<\/p>\n
Hovering insects<\/a> like the hummingbird clearwing moth move their wings in a figure-eight motion, generating lift on both strokes.<\/p>\n Their flexible wings deform with each beat, giving them remarkable control and agility, a principle UC engineers are now translating into robotic design.<\/p>\n Eisa believes the implications go beyond drones. \u201cIt could change a lot of things about biophysics,\u201d he said. \u201cIf it is the case that hovering insects like moths use the equivalent of our extremum-seeking feedback, it probably evolved in other creatures as well.\u201d<\/p>\n By studying nature\u2019s smallest flyers, UC researchers are uncovering how precision and stability emerge from simplicity, revealing lessons that could transform both drone<\/a> technology and the understanding of flight itself.<\/p>\n