Development is progressing on a drone designed to inspect sewer tunnels.

This past week, the latest prototype of the robotic aerial unit was deployed in the sewer system of Barcelona, Spain. The project is the undertaking of several companies within the framework of the European Coordination Hub for Open Robotics Development.

“I think drones can be very useful as support tools in places that are difficult to access or dangerous for humans to work in,” says Francois Chataigner, programming manager with Eurecat, one of the organizations involved, in the video below.

The drone has a 3D camera for color and depth, as well as to calculate its position and speed. A 2D laser detects tunnel walls and calculates the flight path in real time. An infrared sensor measures the distance from the pipe floor and controls the flying altitude. An autopilot feature turns the flight path into low-level commands for the drone’s four motors.

“Sewer environments are very challenging for drones, mostly because there is no GPS or external positioning source. This means the drone has to calculate its position and speed all on its own, using only the data available in the sewer itself,” says Chataigner.

Other challenges the team has had to overcome include equipping the drone to be able to handle some level of water and dust exposure, and the turbulence created by the motors in an enclosed space that make flying difficult. The project is currently in its second phase, which involves finalizing a prototype. The third and final phase in 2018 will consist of small-scale field trials with the goal of getting as close as possible to a commercially viable product.

Check out more about the project in this video: