Title
Defect Detection for a Vertical Shaft Surface Based on Multimodal Sensors
Abstract
Hydroelectricity is a major source of renewable electricity originating from a turbine driven by dammed large-volume water via a penstock or a drop shaft. Shafts suffer from risks of collapse due to the pressure from exterior structures and the erosion from inner water flow. Vertical shafts are an important part of hydroelectric power generation systems, and detecting defects in shafts guarantees the stable operation of hydropower stations. However, shaft defect detection is a great challenge due to the poor conditions, large drop in height, limited entrance size, lack of light, and damp air, where suitable technology and equipment are not available. Aiming at defect detection for vertical shafts, we have developed a defect-detecting system based on unmanned airships, integrated panoramic CCD cameras, three-dimensional laser scanners, inertial measurement units, barometric altimeters, illumination sensors, and control modules. Shaft defect detection methods are proposed by fusing the multimodal image features to extract typical defects on concrete surfaces. Compared with machine learning methods, the proposed method achieves the highest overall accuracy of 90.90% for defect detection. Our system was validated by experiments in the shafts of the Nuozhadu hydropower station to be functional for defect detection, which demonstrates its capability of reducing the risk of collapse and improving safety.
Year
DOI
Venue
2022
10.1109/JSTARS.2022.3195977
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
Keywords
DocType
Volume
Shafts, Hydroelectric power generation, Point cloud compression, Remote sensing, Inspection, Cameras, Dams, Data acquisition, defect detection, hydropower station, multimodal sensors, unmanned airship, vertical shafts
Journal
15
ISSN
Citations 
PageRank 
1939-1404
0
0.34
References 
Authors
0
7
Name
Order
Citations
PageRank
Xu Chu100.34
Luliang Tang25910.87
Fei Sun3237.74
Xi Chen47426.21
Le Niu500.34
Chang Ren600.34
Qingquan Li71181135.06