The Use of Unmanned Aerial Vehicles for Sloped Roof Inspections – Considerations and Constraints

Abstract

Building roof inspections should be performed periodically to ensure repairs and replacements are done in a timely manner. These inspections get neglected on sloped roofs due to two factors: the inefficiency of manual visual inspections, and the difficulty of accessing sloped roofs. Walking a roof to inspect each tile is time consuming. As roof slope increases so does this difficulty, increasing the time needed for an inspection. Additionally, there is an inherent safety risk involved. Falls from roofs tend to cause serious and expensive injuries. These two factors, safety and efficiency, motivated this study, the purpose of which was to determine whether Unmanned Aerial Vehicles (UAVs) can be used to perform sloped roof inspections efficiently, thus eliminating the safety risk involved in manual inspections. The metric for determining whether this is possible was that there is a UAV available on the market that (1) produces images in sufficient quality to make maintenance decisions, (2) can be flown efficiently enough so that the inspection process can be done in less than two hours for a building with a roof of about 30,000 sqft, (3) can be controlled safely by amateur pilots, and (4) is reasonably priced. The study was done in three phases. Phase 1 addressed the choice of UAV. Phase 2 explored image quality and UAV flying. Phase 3 developed the optimal approach. The study found that an economic UAV can be used in a way that makes manual inspections unnecessary. Still images and manual UAV control were sufficient and large roofs could be done in well under two hours using a three-step approach with images taken at various heights. This study has therefore identified an economical and effective technology-based alternative process for sloped roof inspection using UAVs that eliminates the risk of working at height.

Automatic assessment of roofs conditions using artificial intelligence (AI) and unmanned aerial vehicles (UAVs)

“…This study explores new possibilities to evaluate and localize the damaged areas in the roofs using the computer vision technique. The study utilizes the transfer learning technique of deep learning technology in which a pre-trained network is taken and fine-tuned until the loss function is minimum (Brown and Miller, 2018). This work incorporates YOLO v5 algorithm for the detection of missing shingles in roofs.…”

Application of unmanned aerial vehicle (UAV) for a safer roof inspection at high rise building

“…UAVs have opened up new opportunities in the built environment industry, such as man-made structures, features, and facilities, by allowing facility managers to document inspections in greater depth and detail [3]. UAVs is equipped with camera that may be used to assess a roof while the UAV flies over it and the camera can record both still photos and video whereby it can be saved and analysed later [11].…”

Data augmentation approach in detecting roof pathologies with UASs images

“…One solution for buildings roofs inspection is Unmanned Aerial System (UAS) for image capture [2]. UASs can provide a large amount of data in a short period, allowing the visualization of pathologies in hardto-reach areas, safely and at low cost, when compared to manual visual inspection methods [3].…”

“…The authors assessed items that can be viewed with UAS and developed a manual flight mode protocol for flight planning and data collection with UAS. Bown e Miller [2] recommends the use of individual still images process for sloped roof inspection with UAS, for being faster than other options (image stitching, video recording, streaming), also providing evidence in a manageable format (small individual photos). According to Silveira et al [3], UAS use allows to increase transparency, simplify steps, decrease the time to carry out roof inspections, speed up the preparation of reports, and apply corrective actions.…”