Developing a climbing robot for repairing cables of cable-stayed bridges

Abstract

It is difficult to test and maintain the cables on a cable-stayed bridge. Cable detection and repair remain mainly manual operations and automatic maintenance is rare. Aiming at the difficulty of detecting and repairing damage to bridge cables, a climbing robot system for cable repair based on an independent quadrilateral suspension was designed. Firstly, an independently suspended cable-climbing robot scheme was proposed and the automatic repair mechanism (including a rotary platform, grinding, cleaning, spraying, and winding mechanisms) was designed. Then, a dynamic model for obstacle negotiation by the climbing robot was established to perform simulation and analysis; subsequently, kinematic and workspace analyses were conducted on the component modules of the robot to optimize the structure of the robot. Finally, a prototype of the cable repair robot was developed, and the experimental platform was established to carry out laboratory testing and in-situ testing of a bridge. Furthermore, climbing and repair tests on cables with diameters of 80 to 140 mm were conducted. The experimental results show that the proposed robot that climbs at the speed of 0.26 m/s can carry a mass of 11.5 kg and cross obstacles 15 mm in height. The climbing robot can fulfill automatic repair of damage to bridge cables with the testing, grinding, cleaning, spray coating, and winding mechanism according to the surface damage encountered. Future research should aim to improve the obstacle surmounting ability of the proposed robot.