Power to the people

Electricity pylons, or transmission towers, have been a critical component of energy infrastructure for decades. The structural integrity of these power towers, which stride across landscapes the world over, is vital to power supply and public safety.

A study in the International Journal of Energy Technology and Policy has investigated a novel, more precise and efficient way to inspect pylons using advanced 3D scanning and geometric analysis. The approach might speed up the shift from labour-intensive field checks to what might be referred to as a fully digital inspection regime.

The researchers explain that a laser system can be used to scan a pylon’s geometry in minute detail to generate a “point cloud”. This is a collection of millions of spatial points representing the pylon’s surface. To assess structural integrity, multiple scans are taken from different angles and then must be aligned into a single coordinate system in a registration process. This typically occurs in two stages: coarse registration, which provides an initial alignment, and fine registration, which refines it to high precision.

The lattice frameworks of pylons with their intersecting beams and sharp edges generate extremely large datasets and create ambiguities when identifying matching features, so registration even with the best algorithms is tough and consequently error-prone. In the IJETP paper, the researchers propose the use of Gaussian curvature in the feature-extraction process required for registration. Gaussian curvature is a mathematical measure of how a surface bends at a given point: flat areas have near-zero curvature, while sharp edges or corners have higher values. Because beam intersections and joints exhibit high curvature, they provide distinctive geometric markers for alignment.

Once aligned, the digital model of the pylon can then be compared with a high-precision reference design to identify geometric deviations. This allows engineers to detect misalignments or structural problems with confidence and so prioritise maintenance and repair across the power grid.

Qi, X., Yan, H., Tu, X., Liu, Y. and Ding, W. (2025) ‘Quality inspection of power transmission towers based on point cloud registration’, Int. J. Energy Technology and Policy, Vol. 20, No. 7, pp.3–22.