Robotic rectification of underwater structural elements in power dams

Hydroelectric power dams are composed of intake and outtake structures made of concrete in which steel components are embedded. These components, for reasons briefly presented in this paper, tend to exhibit considerable wear and deformation with time. Rehabilitation of these embedded components, by rectification using machining techniques, can in some cases be the best approach. This work is traditionally done by human workers who, when possible, work in dry conditions. Drying out the structures can be very costly and sometimes impossible, in which case the work is done by divers. This paper presents a new and innovative approach to accomplishing these rehabilitation tasks. Two different submersible robotic systems are proposed. One system uses a milling process and is designed for vertical components. The second system uses a grinding machining process and is designed to rectify horizontal surfaces. The technical aspects of both systems are described.