Adapting 360-degree cameras for culvert inspection: Case study

Prior video technologies such as closed-circuit television (CCTV) cameras have been used for culvert inspection. They are limited by the range of the area scanned and by the direction in which the camera is oriented because of a limited field of view (FOV). In this research, a 360-degree camera mounted on a remote-controlled crawler was designed and modified to travel through a culvert to scan and take videos of the culvert's interiors. With the unique mounting and coverage of the 360-degree camera, a continuous view of the inner walls of the culvert was captured, as if by a human eye, making visual inspection of hard-to-reach areas possible. The video was analyzed manually, and areas suggesting defects were studied. Snapshots of defective areas were further analyzed using computer software developed in-house, where defects were identified by differences in color and texture. Calculations made from the data collected helped to pinpoint the location of the defects within the culvert and estimate the area of the defects in order to provide culvert inspectors with quantitative information on the condition of the infrastructure.