Unmanned robot system for structure health monitoring and non-destructive building inspection, current technologies overview and future improvements

Inspection is a major issue with respect to the integrity and health of engineering structures. Many of those structures deteriorate at locations that are difficult to assess (for example a roof of a very tall building). State-of-the-art inspection methods are mostly visual inspections completed by trained inspectors, where inspections are time consuming, costly and dangerous. In order to reduce the risk and cost and increase the accuracy of inspection/monitoring, unmanned robotic systems (aerial or ground based) can therefore be of invaluable help. The research groups at both Fraunhofer IZFP and Saarland University have carried out experiments using micro aerial vehicles equipped with an off the shelf camera for building inspection and structural health monitoring over years. Many of the state-of-the-art technologies regarding image processing, robotics and 3D model reconstruction have been tested and evaluated with real engineering applications. The first part of this paper will be discussing our experience, the limitation of state-of-the-art technologies and experimental results of building inspection/monitoring, which includes methods of displaying image results in both 2D and 3D. Based on the results of the first part, the second part of the paper will focus on the improvement of image acquisition and stabilization. The last part of the paper will be discussing how other evelopments in robotics system (both aerial and ground) have a potential to fulfill future requirements in terms of building infrastructure life cycle management.