A novel underwater dam crack detection and classification approach based on sonar images.

Pengfei Shi,Xinnan Fan,Zubair Khan,Min Li,Jianjun Ni,Jonathan A Coles

doi:10.1371/journal.pone.0179627

Abstract

Underwater dam crack detection and classification based on sonar images is a challenging task because underwater environments are complex and because cracks are quite random and diverse in nature. Furthermore, obtainable sonar images are of low resolution. To address these problems, a novel underwater dam crack detection and classification approach based on sonar imagery is proposed. First, the sonar images are divided into image blocks. Second, a clustering analysis of a 3-D feature space is used to obtain the crack fragments. Third, the crack fragments are connected using an improved tensor voting method. Fourth, a minimum spanning tree is used to obtain the crack curve. Finally, an improved evidence theory combined with fuzzy rule reasoning is proposed to classify the cracks. Experimental results show that the proposed approach is able to detect underwater dam cracks and classify them accurately and effectively under complex underwater environments.

Highlights

Numerous factors such as cracks, abrasions, cavitation, and erosion can threaten the safety of a dam [1]
This paper considered the underwater dam crack detection and classification problem, and proposed a novel approach
The statistical parameters of the image blocks constructed in the 3-D feature space and the image blocks are used to facilitate crack clustering analysis

Summary

Introduction

Numerous factors such as cracks, abrasions, cavitation, and erosion can threaten the safety of a dam [1]. Cracks are always used to indicate the degree of risk in the field of dam damage, which has attracted the attention of numerous scholars [4]. Various traditional methods such as electrical prospecting, elastic wave testing, tomography, and ground penetrating radar [5,6,7] are employed to detect cracks in dams. Some of these methods are expensive, and others are neither sufficiently convenient nor reliable. Detecting underwater dam cracks using sonar images has become one of the most important methods because it is nondestructive, intuitive, convenient and efficient [8]

Methods

Results

Discussion

Conclusion