Cable Climbing Robot Research Articles

Development of cable-climbing robot with inspection function

Abstract The primary purpose of this study is to research and develop a crawler-type cable climbing robot to meet the demand of Sinotech Engineering Consultants, Ltd, using excellent structural design to meet the current practical requirements of the application of cable diameter varies greatly and simplify the operation process, improve the efficiency of the safety inspection of bridge cables and reduce the related risks, and through numerical analysis and the finite element method to optimize the design. The design is mainly divided into three parts: vibration measurement mechanism, robot control system, and cable climbing mechanism. The vibration measurement mechanism adopts the micro-vibration measurement method, in which a 3-axis piezoelectric accelerometer is tightly attached to the cable to measure the resonance frequency of the cable and detect the cable force. The robot control system adopts the fourth-generation Raspberry Pi as the central controller, with a ground remote control system and a backup system to prevent the robot from losing control due to the failure of the central system. The drive unit adopts a stepping motor with a planetary gearbox to drive the crawler. The cable-climbing mechanism uses a compression device to keep the robot’s track close to the cable to achieve a maximum speed of 0.04 m/s and to cross an obstacle limit of 9 mm over a 60-200 mm vertical or horizontal cable. The tracked cable-climbing robot is tested to be installed and operated by a single person and is adaptable to different cable environments with rapid deployment and operation.

Dynamic modeling and analysis of a cable-climbing robot with a magnetorheological damper under wind action

Dynamic modeling and analysis of a cable-climbing robot with a magnetorheological damper under wind action

Application of Cable Climbing Robot Automation Control Technology in Bridge Cable Measuring System

According to the traditional bridge cable measurement system, the accuracy of the bridge cable measurement is low, and the measurement time is long. Based on the automatic control technology of the climbing robot, a new bridge cable measurement system is designed. We design system hardware through CIS drive circuit, main controller, and communication module; design system software on the basis of hardware design; obtain the motion control equation of orthogonal joint cable climbing robot through DH transformation; and apply this equation to the bridge cable measurement system. The bridge cable measurement model is constructed, and the bridge cable measurement system design is completed through the system hardware design and software design. The simulation results show that the designed system has higher accuracy in measuring bridge cables and shorter measuring time.

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

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.

Geometrical motion planning for cable-climbing robots applied to distribution power lines inspection

ABSTRACT This paper describes a kind of mobile robot, named cable-climbing robot, and its motion planning development. That robotic system is capable of moving over electricity distribution lines, which can easily overcome the obstacles present in those installations like insulators, thanks to its kinematic motion planning of collision avoidance. The cable-climbing robot avoids the obstacles by the adoption of sequential movement planning with the objective of climbing insulators in electric posts. This approach avoids the obstacles, making the robot-articulated suspensions to retract when it is close to the obstacle and to distend after it passes over it. This kind of movement is controlled by a geometric motion planning method which is performed by the quintic polynomial interpolation law. The kinematic modelling uses the screw-based Jacobian Method combining with Virtual Kinematic chains, which permits the usage of the Kirchhoff-Davies method. Thus obtaining the cable-climbing robot inverse kinematic model. Simulation shows the potential use of this technique to cope with the cable-climbing robots control.

Design and Implementation of a Cable Inspection Robot for Cable-Stayed Bridges

SUMMARY Cable is the most important bearing structure of the cable-stayed bridges. Its safety has been of crucial public concern. Traditional manual cable inspection method has many defects such as low inspection efficiency, poor reliability and hazardous working environment. In this paper, a new wirelessly controlled cable-climbing robot enabling safe and convenient inspection of stay cables is proposed. The designed robot is composed of two modules, joined by four turnbuckles to form a closed structure that clasps the cable. The robot is controlled wirelessly by a ground-based station, and a DC power is supplied via an onboard lithium battery. The climbing principle and mechanical structure of this robot are introduced. The static model of the robot during obstacle negotiation is established. The relationships of the driving force and resistance with obstacle height to determine the obstacle-negotiation capability of the robot are obtained. The effects of cable diameter, cable inclination and preload force on obstacle climbing ability of the robot are also analyzed. The experiments verify that the robot could climb random inclined cables and overcome an obstacle of 2.42 mm in height with a mass of 5 kg payload.

Dynamic obstacle-surmounting analysis of a bilateral-wheeled cable-climbing robot for cable-stayed bridges

PurposeField robots can surmount or avoid some obstacles when operating on rough ground. However, cable-climbing robots can only surmount obstacles because their moving path is completely restricted along the cables. This paper aims to analyse the dynamic obstacle-surmounting models for the driving and driven wheels of the climbing mechanism, and design a mechanical structure for a bilateral-wheeled cable-climbing robot to improve the obstacle crossing capability.Design/methodology/approachA mechanical structure of the bilateral-wheeled cable-climbing robot is designed in this paper. Then, the kinematic and dynamic obstacle-surmounting of the driven and driving wheels are investigated through static-dynamic analysis and Lagrangian mechanical analysis, respectively. The climbing and obstacle-surmounting experiments are carried out to improve the obstacle crossing capability. The required motion curve, speed and driving moment of the robot during obstacle-surmounting are generated from the experiments results.FindingsThe presented method offers a solution for dynamic obstacle-surmounting analysis of a bilateral-wheeled cable-climbing robot. The simulation, laboratory testing and field experimental results prove that the climbing capability of the robot is near-constant on cables with diameters between 60 and 205 mm.Originality/valueThe dynamic analysis method presented in this paper is found to be applicable to rod structures with large obstacles and improved the stability of the robot at high altitude. Simulations and experiments are also conducted for performance evaluation.

Kinematic and Dynamic Analysis of a Cable-Climbing Robot

To inspect broken cables or a cracked protective layer on cable-stayed bridges, a cable-climbing robot has been proposed and designed. In this paper, the complex 3D obstacles that may be encountered on cables are theoretically described, in order to investigate the obstacle-climbing capability of the cable-climbing robot. A climbing model is then proposed and used to design the robot. In the climbing model, two driven wheels are independently supported with a spring. Kinematics and dynamics models are further derived for the obstacle-climbing capabilities of the driving and driven wheels of the robot. In addition, the robot's obstacle-climbing tracks and its obstacle-climbing performance are simulated. Payload and obstacle-climbing experiments were conducted on the climbing robot in the laboratory. Based on the results of the simulation and the experiments, we obtained the variation of the driving torque in obstacle climbing. The contribution of this paper is intended to provide a basis for the precise motion control of the robot.

Magnetic Flux Leakage Sensing-Based Steel Cable NDE Technique

Nondestructive evaluation (NDE) of steel cables in long span bridges is necessary to prevent structural failure. Thus, an automated cable monitoring system is proposed that uses a suitable NDE technique and a cable-climbing robot. A magnetic flux leakage- (MFL-) based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF) of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the levels of damage. Measured signals from the damaged specimen were compared with thresholds that were set for objective decision-making. In addition, the measured magnetic flux signals were visualized as a 3D MFL map for intuitive cable monitoring. Finally, the results were compared with information on actual inflicted damages, to confirm the accuracy and effectiveness of the proposed cable monitoring method.

Inspection Robot for Hanger Cable of Suspension Bridge: Mechanism Design and Analysis

Periodic maintenance of suspension bridge is critical to the safety of the bridge structure. Because most of the load on the bridge is supported by the cables, inspections on main cable or hanger are very important. In this paper, we propose a cable-climbing robot enabling convenient and safe visual inspection of the hanger cable. The robot is comprised of three identical modules assembled 120 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> apart circumferentially on a frame around the cable, and each module has three functional mechanisms, that is, driving, adhesion, and safe landing. The robot is controlled wirelessly by an operator on the ground, though ac power is supplied via a tether cable. In addition, the vision sensor consisting of three cameras provides images taken from three different directions covering the cable and the odometer made with a soft idler wheel locates the robot on the cable. The robot is able to transmit the visual images of the cable surfaces in realtime at a position, while climbing up and down. In this paper, the kinematic and force analysis of the robot is performed and its feasibility is experimentally demonstrated.

Local Damage Evaluation Technique Using Elasto-Magnetic Sensors Operated on a Cable Climbing Robot

Local Damage Evaluation Technique Using Elasto-Magnetic Sensors Operated on a Cable Climbing Robot