Tall Chimney Lining Inspection using Structure from motion and drone photography

Abstract

Recently, in the practical inspection on inner lining of tall chimneys of plants or power stations, the movie captured by 360-degree action camera installed on drone is reviewed by engineer for screening. It reduced man-hours and increased safety than visual inspection using scaffold.

Due to the safety in operation in closed space and short life cycle in the severe environment, the drone and equipment should be small, light and low cost. The drone is operated manually without GPS-based navigation.

To improve the precision, we tried capturing 1mm resolution images of inner surface of a tall chimney 150 meter in height with single compact digital camera in two days. Photogrammetric processing using SfM/MVS delivered pointcloud, and it was developed into elevation plan view, which crucks was extracted.