Abstract

Only a few attempts have been made to investigate the possibilities of developing chain climbing robot due to the complexity of the structure and physical nature of chain links. Mooring chains are subjected to large tidal waves, harsh environmental conditions and storms on a daily basis. Therefore, periodic inspection of the integrity of chain links is important. Work reported in this paper investigates the possibilities of mooring chain climbing by using tracked wheel locomotion. The permanent magnet adhesion, tracked wheel crawler robot developed for this purpose can climb on mooring chains both in air and underwater with a variable speed according to the inspection requirements (maximum speed of 42cm/minute). It is able to handle an external downward force of 50N during the climbing motion. Numerical modelling based analysis of a magnet adhesion module and the strength of the robot structure is validated with prototyping and testing of the concept.

Highlights

  • Mooring chains were first introduced in 1808 to improve the securing of larger ships

  • Ensuring the integrity of mooring systems for FPSO needs to be addressed with a capability of handling in-situ conditions, because most of the off-shore floating oil production systems are not able to move for inspection or repair

  • The necessity of ensuring their integrity arises because mooring chains are subjected on a regular basis to high tidal waves, storms and harsh environmental conditions

Read more

Summary

INTRODUCTION

Mooring chains were first introduced in 1808 to improve the securing of larger ships. Integrity of mooring chains is an important factor when considering the industrial and environmental safety of FPSOs. Using Non-Destructive Testing (NDT) methods with divers (NDT operators) is the most common method of mooring chain inspection. Two crawler modules are attached to the body of the mooring chain at a given time using magnetic adhesion while the other two are suspended in air. This is due to 90 degrees orientation difference between two adjacent mooring links. A magnetic flux concentration technique is adopted to optimize the dimension and weight of the adhesion module This prototype system can successfully travel along vertically aligned mooring chain links. The paper presents the structural design, FEA analysis, motor selection, adhesion force requirements, prototyping of the concept, and experimental testing of the prototype

STATE OF THE ART
Concept of the mooring chain climbing robot
Frame design
Optimization of the magnet module
Crawler unit design
PROTOTYPING AND VALIDATION
Selection of motors
Magnetic forces validation test rig
Motor attachment and control unit
CONCLUSIONS
FURTHER IMPROVEMENTS

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.