Drone Inspections for Transportation Structures: A Case Study
Since about 2015 or so, drones have become an increasingly popular recreational and commercial device. At Entuitive, we see a lot of potential to integrate drone footage into many of our services, such as for remote visual inspections of existing buildings and bridges. It can be orders of magnitude more economical and efficient to perform a drone inspection of a given building or bridge rather than shutting down operations completely in order to perform the same inspection manually.
In this article, we’d like to present a case study of work Entuitive has recently undertaken that shows how effective drone inspections can be.
Toronto Pearson International Airport Guideway, Trial Inspection
Toronto Pearson International Airport features an Automated People Mover (APM) that connects Viscount Station, Terminal 1, Terminal 3, and the UP Express. Every two years, the Greater Toronto Airport Authority (GTAA) must commission an inspection of the APM Guideway (Guideway) to ensure its good working condition.
Historically, the APM system has been shut down to allow engineers access to the Guideway to complete the inspection, usually via the Doppelmayr Cable Car Maintenance Vehicle. To supplement the APM shutdown, a fleet of busses is commissioned to transport airport passengers at a considerable expense to the GTAA.
Hoping to find a better way to perform these inspections, the GTAA retained Entuitive in collaboration with ZeeDrone Aerial Solutions for a test inspection to determine the feasibility of performing these biannual Guideway inspections via drone. The test inspection sought to understand and validate whether inspection data in the form of drone photographs and video footage could be used to complete a visual inspection, and whether a drone could operate safely in the areas around the Guideway.
In coordination with GTAA and NavCanada, a variety of flight paths were pursued to capture multiple angles of the Guideway, including directly on top of it, its port side, starboard side, and directly underneath it. In addition, each truss of the Guideway was captured from eight different camera angles, ensuring sufficient data for the engineers to view any defects from multiple perspectives.
In total, 643 videos were captured of the 78 Guideway spans during the test inspection, of which more than 90% were afterwards deemed suitable for inspection purposes, when compared with manually taken photos from the previous Guideway inspection. As such, Entuitive and ZeeDrone’s test flights confirmed both the quality of drone inspection data and that the drone could operate safely around the guideway.
In addition, the drone inspection took a significantly shorter amount of time to complete than typical manual inspections. Historically, an inspector would have to climb through the APM truss structure to capture inspection data, which typically took to two to three weeks per system, during which time the trains needed to be shut down. The drone trial inspection, on the other hand, was completed in 13 days, which is 43% – 65% faster than traditional methods and did not require shutting down the trains and commissioning busses.
For future inspections using drone technology, Entuitive and ZeeDrone recommended a tiered approach. The purpose of the tiered approach is to reduce the APM shutdown time by acquiring as much inspection data as possible using a drone. The inspectors could then review the data and identify potentially problematic areas that require a closer look in person using traditional methods.
Conclusion – Other Potential Use Cases
We see many good uses cases for drone inspections in addition to guideway work, such as for existing building and bridge inspections. Drones can reach many locations and positions that may not always be practical or cost effective for a person to inspect manually, and with the high-quality resolution of these images and videos, as seen in the images above, many potentially dangerous inspections could be avoided as well.
For more information on how Entuitive and ZeeDrone can work with your team on drone inspections, reach out to Nicholas Greven.