Crack Detection Assisted by an Unmanned Aerial Vehicle for Wonjudaegyo Bridge in Korea

Abstract

Since the 1970s, Korea has achieved exponential economic growth over a short period of time, with a huge amount of infrastructure built. However, 30 years on, this infrastructure is now deteriorating at a rapid pace due to extensive use and climatic factors, raising safety issues in recent years. The current task force faces limitations in monitoring and maintenance due to various reasons: Insufficient budget, increasing number of infrastructure facilities requiring maintenance, shortage of manpower, and a rapidly increasing number of aging infrastructure facilities. To overcome these limitations, a new approach is required that is different from the manual inspection methods under the existing rules and regulations. In this context, this study aimed to explore the efficiency of bridge inspection for cracks by an Unmanned Aerial Vehicle (UAV) that could observe inaccessible areas, could be conveniently and easily controlled, and could offer high economic benefits. A case study of UAV-based crack detection for Wonjudaegyo Bridge, Korea was performed. The results show more effective detection of cracks in the structure than traditional methods.

Bridge Inspection with an Off-the-Shelf 360° Camera Drone

“…The author successfully managed to use an off-the-shelf drone with an off-the-shelf 360 • camera on top of the vehicle for bridge inspection. This generally supports earlier studies by inter alia [9,10,12] that all used drones for bridge inspection. Seo et al [10] used an off-the-shelf DJI Phatom 4 without modifications to inspect a timber girder bridge.…”

“…Seo et al [10] used an off-the-shelf DJI Phatom 4 without modifications to inspect a timber girder bridge. In contrast, Sanchez-Cuevas et al [12] used a self-made drone with an ultrasonic sensor that required physical contact with the surface of the bridge, whereas Lee et al [9] applied a Leica Aibot drone system that costs 50,000 USD. Therefore, many researchers have either used self-made special-purpose drones or very expensive industrial drones.…”

“…The bridge was designed by Riccardo Morandi and opened to the public in 1967. The increasing problem of deteriorating bridges and the lack of sufficient maintenance is well documented in the literature (see inter alia [6,[9][10][11]). Maintenance of old bridges is complicated and expensive.…”

Geodetic Altitude from Barometer and Weather Data for GNSS Integrity Monitoring in Aviation

“…However, the approach adopted for correcting pressure altitudes makes limited use of weather measurements, and the conversion to geometric altitudes does not include the altitude scale conversion (SESAR, 2021). Similarly, S. Jan et al (2008) and Lee et al (2016) corrected the pressure altitude by using (limited) external weather data and neglected the scale conversion when translating the corrected pressure altitude to geodetic altitude. Xu et al (2021) did not mention any correction or conversion from barometric pressure to geodetic altitude.…”