HELIX CABLE-DETECTING ROBOT FOR CABLE-STAYED BRIDGE: DESIGN AND ANALYSIS

Fengyu Xu, Jinlong Hu, Xingsong Wang, and Guoping Jiang

Keywords

Cable-detecting robot, helix cable, permanent magnetic absorption, centrifugal speed regulation

Abstract

In contrast to common smooth cables, helix cables possess a spiral circular salient with a diameter ranging from 6 to 10 mm on their surface. Helix cables can effectively inhibit the wind- and rain-induced vibrations of cables and are thus commonly used on newly built bridges. In this study, a helix cable-detecting robot is proposed to inspect the inner broken wire condition of helix cables. This robot consists of a driving trolley, as well as upper and lower supporting links. The driving trolley and supporting links were connected by fixed joints and are mounted opposite to each other along the cable. To ensure that the body of the robot is not in contact with the cable surface, a magnetic absorption unit was designed in the driving trolley. A climbing unit was placed on the body of the robot which can enable the trolley to rotate arbitrarily to adapt its water conductivity lines on cables with different screw pitches. A centrifugal speed regulation method was also proposed to ensure the safe return of the robot to the ground. Theoretical analysis and experimental results suggest that the mechanism could carry a payload of 1.5 kg and climb steadily along the helix cable at an inclined angle ranging from 30° to 85°. The load-carrying ability satisfied the requirement to carry sensors or instruments such as cameras to inspect the cable.

Important Links:

Go Back