Drones Fly to the Aid of 15th Century Cathedral

The use of drones to inspect a historical monument has implications for applications for industrial assets—not only outside, but inside as well.

As drone technology takes off, so to speak, people from all walks of life are finding ways to leverage the capabilities to make jobs safer, more efficient and less costly. In the latest example from Intel, 21st century drone imaging technology is being used to inspect and assess wear and tear on a 15th century German cathedral.

The data captured by the Intel Falcon 8+ will help to inform restoration planning for the Halberstadt Cathedral, built between 1236 and 1491 in Saxony-Anhalt, Germany. In collaboration with experts from Bauhaus University Weimar and Kulturstiftung Sachsen-Anhalt, a foundation for the preservation of cultural monuments, Intel is powering inspections and damage assessment of the cathedral with its advanced commercial drone technology.

Though damage to the Halberstadt Cathedral was repaired in the decades after World War II, the historical structure has since seen plenty of deterioration simply from environmental conditions. Using drones for inspection rather than traditional condition surveys and structural health monitoring makes the surveys easier and less costly to conduct. The imaging-based drone inspection is also a non-invasive way to get at fragile, hard-to-reach structures—particularly important because of the delicate condition of the Gothic-style church and its artwork.

“Advanced technology, like the Intel Falcon 8+ drone, provides enormous potential for structural monitoring,” said Norman Hallermann, a research associate on the faculty of civil engineering at Bauhaus University Weimar. “Working with Intel drone technology has allowed us to reach previously inaccessible spaces, like the cathedral’s bell towers.”

Though ladders and scaffolding will still be used in the actual maintenance and restoration process, the drone-based evaluations help to keep that to a minimum. It helps the maintenance team decide which parts of the building they need to approach and also prioritize where to go first, commented Anil Nanduri, vice president of new technology and general manager of unmanned aviation systems for Intel.

“Traditional inspections and maintenance include building scaffolding, climbing up and looking for defects. Software can help identify defects for you without having to have people climb up there,” Nanduri said. “Keep in mind that, if I have to inspect manually, it’s a historical monument. Scaffolding has risk to the integrity of the infrastructure. With drone imaging, you only do the work you absolutely need to do.”

Applications in industry

This same philosophy applies to many different assets in the industrial and utility space as well—communication towers, transmission lines, oil and gas refineries, airplane inspections and so forth. “How do I inspect these other assets, especially large-scale assets? They’re either hard to reach or have some element of human safety,” Nanduri said. “Inspection clearly can be streamlined by using drones and drone sensors.”

>>See how GE Global Research and Avitas Systems are using drones to inspect critical infrastructures in oil and gas, transportation and energy industries.

And, though most of the use cases we’ve seen so far relate to outdoor inspections, there are plenty of prospects for bringing drone technology inside as well. In fact, in this case with the Halberstadt Cathedral, several damaged statues also benefited from the new approach to mitigate the potential risk of damage from ladders or scaffolding inside the church as well. These stone statues, nearly 20 feet above the cathedral floor, are in precarious condition because of their fragile state and delicate color pigment, which is now a detached shell on the stone surface.

“There were statues up by the ceiling that were very high,” Nanduri commented. “Flying the drone was less invasive.”

For the indoor applications, the drone had to be flown manually. Work still needs to be done, Nanduri said, to make it safe to let the drones fly inside autonomously—including recreating a positioning environment and improving indoor location technology. Drones use GPS technology for positioning, and indoors GPS capabilities go away. “We need to solve that problem,” he said. “But there are many, many applications where you can use drones indoors as well.”

One industrial application that Nanduri described is the use of drones to get parts to an assembly line. Mobile robots are catching on in material handling as manufacturers find the need for more flexible operations, and drones could be an important part of that mobility. “If somebody’s waiting for a screw, that may be stalling the whole assembly,” he said. For an assembly line the size of a football field, the drone could bring that screw quickly and effortlessly. Drones could also be used to track inventory in a vertical storage arrangement, he added.

Potential ROI, now and future

Though the cost savings for drone usage over standard structural surveys can vary widely, Intel has done ROI analysis that points to a 350 percent improvement in efficiencies, Nanduri said. That equates to considerable cost savings. “While we are just in the beginning stages of this three-year project, the costs saved by carrying out these inspections via a drone are already being put towards further conservation efforts,” Hallermann noted.

Much of the potential for making drones even more worthwhile will come from improved analysis of the data that the drones gather. At the cathedral, the Intel Falcon 8+ drone captured nearly 1,000 detailed images (and additional footage) in less than an hour of total flight time. That data was post-processed to generate precise 3D structural models for the team to analyze.

Though the imaging in this case was purely high-resolution RGB technology, drones could also be equipped with infrared or thermal sensors to help detect structural integrity issues. That could be particularly helpful in assessing damage of industrial assets.

“Each drone can collect about 1,200 images. But manually scanning them actually becomes much more tedious work that just looking at the structure in real life,” Nanduri explained. He pointed to the importance of Intel Insight—a cloud-based platform to streamline data management. “It needs to come down to a simplification process. That’s where the automation will evolve into.”

The machine learning will benefit greatly as more and more data is collected on more and more projects. “If we’ve inspected 10 other cathedrals, then we can see here are the issues we’ve found learning from the first ones,” Nanduri said. “The system is able to understand what is a problem, and it can easily learn and use that for other applications. That is the phase of automation that you’ve seen evolve.”

The application of drones—whether preserving cultural monuments or inspecting the integrity of an oil pipeline—is still relatively recent. Applying increased computing power will push activity further. “The potential of drones for making these safer, more efficient, more accurate and less expensive is where the promise of this technology is,” Nanduri said. “And using the Moore’s Law of computing to help have that transformation, to help analyze, that’s the way of the future.”

Take a 360-degree tour to learn more about the Halberstadt Cathedral. Also, check out video footage with more details about the drone imaging of the cathedral, including the discovery of a small shingle (20 x 15 cm) that had become detached from the roof and was about to fall off. (There are also several other videos on the page that you can explore to learn more about Intel’s drone achievements.)

Companies in this article
More in Robotics