Multifunctional Robotic Crawler for Inspection of Suspension Bridge Hanger Cables: Mechanism Design and Performance Validation

This paper presents a robotic system, called multifunctional robotic crawler for cable INspection II, which is developed for inspection of hanger cables of suspension bridges. The robot can move over hanger cables and perform inspections with instruments such as cameras, nondestructive testing tools, etc. The novel mechanisms for the robotic system are proposed under the consideration of the environmental conditions of suspension bridges. Its driving mechanism adopts a crawler type one driven by brushless direct current motors, and the detachable adhesion tool ensures simple and quick installation procedures. The safe-landing mechanism for emergency situations guarantees the retrieval of the robot while preserving the safety of operators. This paper presents the robot system and its field test results under a super long-span suspension bridge, called Yeong-Jong Grand Bridge in South Korea. For practical applications, the real environmental conditions of a suspension bridge and the other fields where the robot can be applied are discussed.