Can drones inspect urban building façades?

 

Today’s research is tomorrow’s design. Doggerel is asking researchers within Arup and beyond to describe their work and its potential applications. Here, Josh Treuhaft and Felix Weber describe their investigations of drone façade studies.

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What are you studying?

We want to understand if drones can be used to inspect building façades in dense urban environments. We recently conducted a test flight in a busy Brooklyn neighborhood, partnering with drone company Measure.

Why is this important? What are the potential implications for the built environment?

Many cities require the owners of multistory buildings to regularly inspect their façades, looking for problems that may lead to injury or property damage — loose masonry at risk of crashing to the sidewalk below, for instance.

These investigations are typically conducted in two stages. In the first, inspectors located on the ground or in adjacent buildings use binoculars to conduct a visual inspection. In the second, they study the façade up close, performing physical tests as needed.

The second stage often requires costly and disruptive interventions to the building and the surrounding neighborhood. Since many buildings lack the equipment needed to safely lower inspectors down the façade, owners frequently erect scaffolding that can block signage, views, and pedestrian pathways — sometimes for weeks on end, depending on the building’s size.

Finding a way to improve the first stage of the inspection in order to shorten the duration of the second could make these studies much cheaper and less invasive. It could also improve inspector safety, reducing the need for climbing around scaffolding or rappeling down the side of buildings.

Drones could help achieve this goal. But while they have been used for façade studies, to our knowledge they’ve never been tested in dense urban areas — in other words, in precisely the environment where they could have the greatest impact.

This mismatch has occurred because of the unique challenges that urban environments pose for drone flight. From privacy concerns to physical constraints — e.g., urban wind tunnels, magnetic shielding, and electromagnetic radiation — we need to understand and address the full range of factors that could influence and impede drone flight in cities.

Our Brooklyn test aimed to help fill in these knowledge gaps, with the goal of developing specifications that others could use when procuring drone services.

Credit: Arup

The outcome: clear identification of drone inspection strengths and limitations.

On the positive side, we were able to capture high-resolution imagery of significantly better quality than that collected through binocular inspections. We also demonstrated that drone-collected data could one day be used to create visually accurate 3D models of the building being examined, offering a much more intuitive interface than the standard practice of storing large numbers of individual photographs in network folders.

The test also confirmed that drone navigation is a key challenge to overcome. The steel and concrete used to build tall structures create magnetic fields that interfere with the drone’s internal compass. As a result, the robots can’t navigate on their own and must be steered entirely by the human project team, which radically limits the distances they can travel. Capturing useful data from every part of the building would require improved drone software.

Drone-CloseUp_HOR_Arup

Brooklyn test flight

What are the next steps for the research?

Arup plans to continue this work, partnering with industry experts to identify safe, efficient, cost-effective ways to conduct façade inspections with drones.

We’re also monitoring the progress of other organizations working in this space. ASTM International, which develops voluntary standards used by industries around the world, is developing its own guidance for drone inspections. This document is expected to be released this year.

Brooklyn test flight

Brooklyn test flight

Our research will evolve over time as technology progresses. As machine learning and artificial intelligence advance, drones could do far more. They could potentially detect changes in the façade by means of computer vision algorithms, for instance, flagging them for later review.

Our team is also interested in the potential for aggregating drone-collected information. If fed into centralized databases, this data could, over time, create an incredible resource for designers and government agencies seeking to understand and improve the built environment.

 

Questions or comments for Felix Weber? Contact felix.weber@arup.com.

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