Houston, Texas, USA – An engineer at the University of Houston has developed a new safety monitor system for quadrotor drones designed to keep them on course and out of danger in real time.

The system is intended to intervene when unexpected events, such as a gust of wind, push a drone off its intended path and toward potential hazards.

Quadrotors, also known as quadcopters, are powered by four rotors and are widely used for tasks ranging from structural inspections to photography because of their agility, precise hovering capabilities, and ability to operate in tight spaces.

Marzia Cescon, David C. Zimmerman Assistant Professor of Mechanical and Aerospace Engineering at the UH Cullen College of Engineering, describes the new technology as a “safety supervisor.”

The system operates as a new onboard module designed to provide run-time assurance by continuously monitoring the drone while it is in flight.

To maintain safety, the module tracks the drone’s tilt and position in real time.

“You can think of it as an invisible fence that defines where the drone can safely be. Whenever the ‘safety supervisor’ predicts that the drone will get dangerously close to the fence and potentially crash onto it, the algorithm we designed pushes it away from it,” said Cescon, who developed and tested the supervisor algorithm in the UH Advanced Learning, Artificial Intelligence and Control laboratory.

The supervisor uses a Control Barrier Function, a mathematical tool that determines when the drone is approaching danger and takes control of the flight to keep it safe.

“This work advances the state of the art by showing how CBF-based RTA schemes can be reliably integrated with standard optimal controllers and deployed on real hardware, highlighting practical tradeoffs between various implementations. The work fills an important gap between CBF and RTA theory and deployable real-world control systems,” Cescon said.

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