Robot-aided tunnel inspection and maintenance system by vision and proximity sensor integration

This article describes an unprecedented alternative to manual procedures for the application of advanced composite materials, such as Fiber Reinforced Polymer (FRP) and epoxy resins. A complete mobile integrated system is presented for the inspection and maintenance of concrete surfaces in tunnels. It allows performance of operations with minimum interference on passing traffic. The core of this system resides in a specially designed light-weight robotic tool, which is sensed and automated for processes. Sensing includes vision and a laser telemeter to assure precise inspection, superficial preparation, and composite application. The designed interconnection flange allows simple and robust attachment of the tool to a robotic arm's tip. The robot–tool set is to be mounted on a standard articulated lift platform. Therefore, an operator can direct the platform and the robot–tool set's operations from a control station placed at ground-level, in a wheeled vehicle on which the articulated lift platform is mounted. A graphical Human–Machine Interface (HMI) has been developed for the system. It allows the operator to identify fissures for the injection of epoxy resin, and weakened surfaces for FRP adhesion. Actual procedures are planned and performed by the system's automatic components.

Research Highlights
► We have developed a mobile integrated system for tunnel inspection and maintenance.
► The core developed robotic tool enables the application of composite materials.
► The system automates several steps in the performance of the selected tasks.
► Demonstrations were performed in real, non-controlled environments.
► The system's ability to perform operations without cutting traffic flow was proved.