In-situ robotic interventions in hydraulic turbines

This paper presents the development and implementation of a robotic technology designed to perform in-situ interventions in hydroelectric turbines. A new manipulator was designed with a unique, track-based kinematics well suited to access turbine blades in a confined space. As most work is done on curved surfaces, the robot relies on a curvilinear space model for trajectory generation. Several processes such as gouging, welding, grinding and hammer-peening have been integrated into the robot to facilitate the maintenance of turbines. The robots have been extensively employed by Hydro-Québec (HQ) for cavitation and crack repairs in its turbines. Recently, the robots were used to perform interventions in turbines based on fluid flow numerical analysis. For these new applications, a technology capable of reshaping the surface´s profile with high precision was developed. More than 30 successful field interventions involving up to three robots working simultaneously have been performed in HQ turbines over the last 15 years.