Quirks & Quarks

Drone 'sheepdogs' steer flocks away from airports to prevent bird strikes

Intelligent autonomous drones can herd birds out of the danger zone and could improve flight safety
Bird strikes number in the thousands per year and have resulted in incidents such as the one that inspired the movie "Miracle on the Hudson". (Getty images)

Drones herd birds away from airports

The struggle to keep flocks of birds away from planes during take off and landing has a new weapon in its arsenal: intelligent autonomous drones are being trained to steer the birds flocks away from airports and thus avoid dangerous bird-strikes on aircraft during take-offs and landings.

Dr. Aditya Paranjape, a Lecturer in Aerial Robotics at Imperial College London, and his colleagues authored a new paper demonstrating the use of an algorithm that enables drones to herd birds up and away from high-risk prone airspace. The idea is not to divide the flock, but to just keep it moving in a safe direction. 

Drones like this one can be trained to herd flocks of birds like robotic sheepdogs.

Bird Strikes

The study was inspired by the thousands of bird strikes that happen each year at airports around the world, some of which can cause major accidents. One such famous strike happened in 2009 when U.S. Airways flight 1549 intersected a flock of Canada geese that took out both of its engines. Skilled pilot 'Sully' Sullenberger glided the plane safely to landing on water with no casualties, which dubbed the event the "Miracle on the Hudson".

But it's not guaranteed to always go so well when birds get caught in the engines, or ding a plane's landing gear. Airports regularly use trained falcons, noise canons, and even humans flying planes that look like falcons to try and drive flocks away from the airports. And if multiple flocks are nearing, falcons and humans can get overwhelmed. Of the many possible advantages to using a drone over these solutions, are that drones can maintain a constant altitude at level with the flocks, and cover very large areas without tiring. 

Falcons are currently used to scare flocks away from airports. (Getty images)

Teaching a drone to herd birds 

The control algorithm they used contains information about how flocks generally behave in nature based on computer modelling called Reynold's rules.These rules encode information about how birds in flocks typically try to not overcrowd their neighbours, but strive to fly at the same velocity as them. By feeding these rules to the drone in the form of an algorithm, the drone can use them to herd the birds away.  

The drone can make calculations about where to position itself in relation to a moving flock and the location of the airport. Imagine the flock represented as a sphere that's moving toward the airport. The drone is able to recognize that sphere, and wants to exert force on it to push it upwards and away from the airport. So it looks for birds that are part of that sphere and it knows from its algorithm how those birds are likely to move.

It also knows how a change in a bird's movement is likely to propagate through the flock. Based on this information, it identifies a series of coordinates under the flock it should position itself at in order to exert pressure on it to move upwards and away from the airport. It then sequentially visits these spots, one by one. If the model used in the algorithm is correct, then the desired effect of moving the birds away will result.

The trained drone positions itself in a way that it can herd the birds away without fragmenting the flock. (Imperial College London)

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