New Model Improves Efficiency and Security in a Fleet of Drones

Drones are smartly and efficiently stepping into roles like search and rescue operation to survey crops and delivering packages at peoples’ doorstep.

Now an Iowa State University researcher says the next step is to expand capacity by deploying fleets of drones. Borzoo Bonakdarpour, an assistant professor of computer science, says unlike piloting a single drone by remote control, operating a fleet requires an automated system that coordinates the task however allows drones to independently respond to weather, a crash or unexpected events.

Bonakdarpour said “The operating system must be reliable and secure. The drones need to talk to one another without a central command telling each unit where to go and what to do when conditions change. We also want to optimize the time and energy to complete the task, because drone batteries only last around 15 or 20 minutes.”

Keeping these requirements in mind Bonakdarpour and his colleagues Anh-Duy Vu with McMaster University, Canada; and Ramy Medhat with Google in Waterloo, Canada developed a mathematical model to calculate the cost – time and energy – to complete a task based on the number of drones and recharging stations available. The model considers the energy required for each drone to complete its portion of the task and fly to a charging station as needed.

From paper the solution needs to be implemented which Bonakdarpour says is a huge challenge. For example, if a battery lasts 15 minutes in the lab, it may drop to 10 minutes on a hot or cold day outside. Locating charging stations is another issue. The optimal placement may be in the middle of a lake and inaccessible in reality.

Based on their model, the researchers developed four operating methods – three offline optimization techniques and one online algorithm. They then conducted a series of simulations using four drones to test for efficiency and security. They found the online algorithm successfully managed the security-energy tradeoff within the energy limits of the drones. The fleet completed all assigned tasks and more than half of the authentication checks. These findings were recently presented by the researchers at the International Conference on Cyber-Physical Systems in Canada.

Operating an automated fleet of drones poses security risks too. Bonakdarpour says with automation drones need to receive GPS signal and position frequently. If the signal drops or the drones fly into an area that is GPS-denied, it can quickly become a problem.

Another problem is software bugs or errors may cause a drone to fly off course and not follow direction to complete the mission. Sometimes hackers could be sending the wrong signal or impersonating a drone of the fleet. While finding solutions will take time, Bonakdarpour says that technology and industry support combined to build infrastructure and charging stations as well as regulatory changes to allow for the operation of a fleet of drones will allow drone fleets to become effective task doers in the near future.