Cable inspection robot for cable‐stayed bridges: Design, analysis, and application

摘要

Abstract As the most important component of cable‐stayed bridges, cable safety has been of crucial public concern. In this paper, a new robot system for the inspection of stay cables is proposed. The robot not only replaces human workers in carrying out risky tasks in a hazardous environment but also increases operational efficiency by eliminating costly erection of scaffolding or dragging of winches. The designed robot is composed of two equally spaced modules, joined by connecting bars to form a closed hexagonal body that clasps the cable. For safe landing in case of an electrical interruption or malfunction, a gas damper with a slider‐crank mechanism is proposed to use up the extra energy generated by gravity when the robot slips down. To conserve energy, a landing method based on back electromotive force is introduced. Laboratory and field experiments verified that the robot can stably climb random inclined cables and land smoothly upon electrical malfunction. Finally, along with an application example, the vision inspection system based on charge‐coupled device cameras, operating modes of the robot, control methods, and feasibility are discussed in detail. The field applications on two cable‐stayed bridges indicate that such a low‐cost robot system can improve the efficiency of inspection operations and satisfy the requirements of actual cable inspection. © 2011 Wiley Periodicals, Inc.