Acronym RIOL
Name Robotic Inspection Over Power Lines
Funding Reference FCT - POSC / EEA-SRI / 60775 / 2004
Dates 2005-09|2008-08

The project aims at developing a prototype robot that uses the infrastructure provided by electric power lines for monitoring/maintenance tasks. Both the power lines and the shield wires provide structured environments for the locomotion of the robot enabling the monitoring of multiple parameters in areas of difficult orography such as in dense forestry.
The primary application for this robot is the inspection/maintenance of the power line infrastructure. Due to the exposure to different weather factors (e.g., sun, rain, wind and snow), materials loose electrical properties causing the disruption in energy distribution. Therefore, it is necessary from time to time, to carry out inspections, aiming at detecting any weakness in such electrical materials that may compromise the energy distribution. These are commonly being done mostly through helicopter based systems. The dangerous nature and the large economical requirements of such operation are pushing forward the development of alternative approaches.
Equally relevant applications of this robot are the monitoring of environmental parameters. The early detection of wild forest fires, environmental pollution and wildlife monitoring are possible with this robot. With multiple robots deployed over selected power lines it is possible to cover a wide area and in some cases to obtain multiple views of the same region.
The project is supported on preliminary studies on the dynamics of a basic serial structure. Using only two rigid links, in the absence of obstacles it is possible to generate a cabbage worm gait. This gait is adequate to the motion and transposition of most of the typical obstacles in the lines. A statically stable variation of the brachiating motion can be used overcome the obstacles present in the lines. Simulation studies (see the bibliography by the project team) show promising results even though some simplifying assumptions in the dynamic modelling.

The project encompasses studies on alternative kinematics, robust control strategies, control architectures and hardware requirements. For the two-link element, the torques required at the actuators tend to be high and hence the payload is severely reduced. Alternative kinematics using parallel structures are foreseen to be useful to reduce the torques needed.
When the lines are in operation the strong electromagnetic field in the neighbourhood of the lines requires special shielding techniques. Though the project primarily focuses on the locomotion aspects of the robot, the requirements on the materials and design of the electronic systems will be addressed.
Simulation of the resulting dynamics models under realistic environment conditions, including motion disturbances induced by atmospheric phenomena, will be used to assess the final characteristics of the prototype prior to production.

Research Groups Intelligent Robots and Systems Group (IRSg)
ISR/IST Responsible
João Sequeira