In South Africa and around the world, electrical utilities are required to inspect power lines and their immediate environment to ensure safe and reliable operation of the electrical network. Such inspections are costly and may be prone to human error. Overhead power lines are valuable assets that are exposed to environmental elements, such as lightning damage, fatigue due to wind-induced vibration, corrosion (especially in salty air) and right of way encroachment. 

This necessitates maintenance of power lines.

Power transmission lines age and therefore, preventive maintenance and inspections is important, therefore, increasing the need for robots that will be able to carry these dangerous tasks efficiently at low costs. Maintaining a grid that spans vast distances is challenging and costly, and how well maintenance is carried out can affect the reliability of electricity supply. Line inspecting robots currently used are large, complex and expensive. Utility companies may also use other inspection methods, such as helicopters, which can be costly; inspectors walking the lines; and remotely operated vehicles (ROV) or robotic patrols.

A cable inspecting robot capable of providing inspection data such as visual, ultraviolet and infrared images of lines and their components, has been developed by UKZN researchers in the Discipline of Mechanical Engineering. This data can be geo-tagged and time stamped, allowing for management of that data over multiple scheduled inspections of the same line. Gathering such inspection data allows for an accurate assessment of line and component degradation, in turn leading to their optimal replacement.

UKZN’ PLIR technology has several advantages over alternative methods, such as:

  • Being less physical demanding on the inspector;
  • Operation being far easier than helicopter piloting;
  • Reduced operational costs;
  • Cameras in close proximity to the line resulting in greater visibility;
  • Being light weight and easy to deploy;
  • Requiring minimal setup to deploy from tower onto a live line;
  • Having the ability to climb around both suspension and strain towers;
  • Having automated sequences for climbing around line hardware;


Principle Investigator: Dr Trevor Lorimer