URARAKA VI : SIX-LEGGED CLIMBING ROBOT WITH SUCKERS FOR 3DIMENSIONAL ENVIRONMENTS : REALIZATION OF MOVEMENT ON VERTICAL WALL AND CURVED COLUMNAR OBJECTS BY EXTENDING THE RANGE Of MOTION OF JOINTS

In recent years, a lot of attention has been placed on the development of robots for maintenance and inspection of large buildings, searching for humans and collecting information in the event of a disaster. These robots are also expected to be used for search and rescue missions in the event of disasters. However, in such unknown complex environments, it is difficult to operate robots autonomously. In previous research, a robot capable of performing the above tasks was developed. In this study, we conduct experiments on pipes by improving the previous robot. robots

SIX-LEGGED CLIMBING ROBOT WITH SUCKERS FOR 3-DIMENSIONAL ENVIRONMENTS

Maintenance and inspection of old buildings, bridges, tunnels, and so on are important tasks of robots. In our previous works, for such tasks, we developed a multi-legged robot that climbs an unknown vertical wall by using suckers. In this report, we improved our previous robot and developed a flexible leg with a sucker to climb a wall. As a result, we confirmed that the developed robot can climb autonomously by utilizing the passive mechanisms

Development of a Chain Climbing Robot and an Automated Ultrasound Inspection System for Mooring Chain Integrity Assessment

Mooring chains used to stabilise offshore floating platforms are often subjected to harsh environmental conditions on a daily basis, i.e. high tidal waves, storms etc. Chain breakage can lead to vessel drift and serious damage such as riser rupture, production shutdown and hydrocarbon release. Therefore, integrity assessment of chain links is vital, and regular inspection is mandatory for offshore structures. Currently, structural health monitoring of chain links is conducted using either remotely operated vehicles (ROVs), which are associated with high costs, or by manual means, which increases the risk to human operators. The development of climbing robots for mooring chain applications is still in its infancy due to the operational complexity and geometrical features of the chain. This thesis presents a Cartesian legged magnetic adhesion tracked-wheel crawler robot developed for mooring chain inspection. The crawler robot presented in this study is suitable for mooring chain climbing in air and the technique can be adapted for underwater use. The proposed robot addresses straight mooring chain climbing and a misaligned scenario that is commonly evident in in-situ conditions. The robot can be used as a platform to convey equipment, i.e. tools for non-destructive testing/evaluation applications. The application of ultrasound for in-service mooring chain inspection is still in the early stages due to lack of accessibility, in-field operational complexity and the geometrical features of mooring systems. With the advancement of robotic/automated systems (i.e. chain-climbing robotic mechanisms), interest in in-situ ultrasound inspection has increased. Currently, ultrasound inspection is confined to the weld area of the chain links. However, according to recent studies on fatigue and residual stresses, ultrasound inspection of the chain crown should be further investigated. A new automated application for ultrasonic phased-array full-matrix capture is discussed in this thesis for investigation of the chain crown. The concept of the chain-climbing robot and the inspection technique are validated with laboratory-based climbing experiments and presented in this thesis