Automatic Extraction of High-Voltage Bundle Subconductors Using Airborne LiDAR Data

Abstract

Overhead high-voltage conductors are the chief components of power lines and their safety has a strong influence on social and daily life. In the recent decade, the airborne laser scanning (ALS) technique has been widely used to capture the three-dimensional (3D) information of power lines and surrounding objects. Most of the existing methods focused on extraction of single conductors or extracted all conductors as one object class by applying machine learning techniques. Nevertheless, power line corridors (PLCs) are built with multi-loop, multi-phase structures (bundle conductors) and exist in intricate environments (e.g., mountains and forests), and thus raise challenges to process ALS data for extraction of individual conductors. This paper proposes an automated method to extract individual subconductors in bundles from complex structure of PLCs using a combined image- and point-based approach. First, the input point cloud data are grouped into 3D voxel grid and PL points and separated from pylon and tree points using the fact that pylons and trees are vertical objects while power lines are non-vertical objects. These pylons are further separated from trees by employing a statistical analysis technique and used to extract span points between two consecutive pylons; then, by using the distribution properties of power lines in each individual span, the bundles located at different height levels are extracted using image-based processing; finally, subconductors in each bundle are detected and extracted by introducing a window that slides over the individual bundle. The orthogonal plane transformation and recursive clustering procedures are exploited in each window position and a point-based processing is conducted iteratively for extraction of complete individual subconductors in each bundle. The feasibility and validity of the proposed method are verified on two Australian sites having bundle conductors in high-voltage transmission lines. Our experiments show that the proposed method achieves a reliable result by extracting the real structure of bundle conductors in power lines with correctness of 100% and 90% in the two test sites, respectively.

Power Line Extraction and Reconstruction Methods from Laser Scanning Data: A Literature Review

“…Column 4 of Table 4 shows the methods which attempt to extract and reconstruct a sub-conductor. For sub-conductor extraction, most of the work conducted by Munir et al [26,51,75,76] using both image-based and point-based methods. All techniques utilised ALS data with multi-bundle configurations on corridors that traverse outside of urban regions.…”

“…These approaches have been evaluated on datasets with a very low point density. With excellent precision, Munir et al [26] and Zohu [74] are able to extract up to four sub-conductors.…”

“…Previously, emphasis was placed on classifying power line points using supervised and unsupervised ALS methods; in addition, the methods were tested on very small datasets or without visual or quantitative results [24,25]. With the advancement of ALS technologies, however, new methods are focusing on robust approaches for single and multi-conductor extraction and have been tested on complex terrains with large data sets [26,27]. In addition, with the advent of mobile laser Scanning MLS and UAV, numerous researchers have proposed new extraction and reconstruction techniques for power lines utilising MLS and UAV platforms [28,29].…”

Real-Time Detection and Spatial Localization of Insulators for UAV Inspection Based on Binocular Stereo Vision

“…Traditional manual inspections have high labor costs and low-efficiency. In addition, unfavorable factors such as climate and the geographical environment will restrict manual inspections, leading to many hidden dangers that cannot be discovered in time [6][7][8].…”

Extraction of Forest Power lines From LiDAR point cloud Data

“…To keep the electrical transmission network cost-effective, safe, and efficient across long distances, electricity is transported over high-voltage power lines, which are made of thin, lightweight wires with low resistance. The distribution of highvoltage power lines is complex (e.g., multi-circuit and multibundle), making power line maintenance more difficult [2]. For safe and dependable transmission, electricity lines must be monitored on a regular basis.…”