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.