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Swarms of drones could be used to tackle natural disasters such as forest fires, researchers at the Indian Institute of Science (IISc) have said.
Climate change is leading to a global increase in the number of forest fires that occur. The researchers have developed an algorithm that allows swarms of drones to communicate with each other and make independent decisions.
When an alarm is raised about a potential fire, the swarms of drones can be sent in. Each is equipped with cameras, thermal and infrared sensors, and temperature detectors to spot the fires.
Once the fire is discovered, the drone closest to it becomes the centre of the swarm and attracts others towards it. Each drone also has the autonomy to calculate the fire’s size and potential spread, and decide how many drones are needed to quench the fire.
IISc professor Suresh Sundaram said: “By the time somebody identifies and reports a fire, it has already started spreading and cannot be put out with one drone. You need to have a swarm of drones – a swarm that can communicate with each other.”
The swarm-based search algorithm developed by the team is key to controlling the drones’ behaviour. Searching for fire cannot be random as the area to explore would be too large. To address this, the researchers took inspiration from the foraging behaviour of a marine predator, a flagellum called Oxyrrhis marina.
Lead author of the study PhD student Josy John said: “When foraging, it first takes longer steps to explore the area. Once it feels like it is closer to the food source, it will reduce the step length and then start exploring the area in more detail.
“The temperature sensors in the drones look for a minimum [threshold] value. When that is reached, the drones reduce their search step, because the fire is near.”
The advantage of using drones is that the decision-making is decentralised, based on data and aimed at maximum efficiency. No more than the required number of drones will be assigned to a fire cluster, allowing others to fan out in search of other clusters.
The researchers have tested specific components of the approach, such as the AI-enabled fire detection using thermal cameras, and accurate payload drop mechanism for fire extinguisher deployment. Full-scale search and mitigation by the swarm is yet to undergo field-testing. Going forward, they plan to combine such drone swarms with unmanned ground vehicles that can carry resources and serve as refuelling stations.
The drone swarms could also be helpful during other natural disasters like floods and earthquakes to locate survivors, deliver water, food and medicines and boost communication, the researchers said.
