X-Scan Consortium revives robotic weld inspection system | Automation.com

X-Scan Consortium revives robotic weld inspection system

 X-Scan Consortium revives robotic weld inspection system

July 18, 2014 - X-Scan is a collaborative project between EU companies and research organisations. Their objective is to develop and produce novel inspection techniques and devices specifically for the inspection of thin steel section welds for the shipping industry. A non-contact laser profile displacement sensor from Micro-Epsilon is playing a pivotal role in the automatic inspection system specifically designed to inspect thin section steels and thin gauge welds on ships and other marine vessels.

The inspection system, X-Scan, is an automatic inspection system that inspects the weld and classifies it by means of laser, ultrasound and electromagnetic methods. The system uses a crawling robot that deploys remote volumetric surface and visual inspection to verify the integrity of welds on the hull plates of ships during manufacture and in the servicing of shipping vessels.

Babcock & Wilcox developed a similar system in the 1970s--a 16-axis robot that used ultrasonic sensors to inspect weld  seams in nuclear reactor vessels.

Structural Failures
In the marine industry, structural failure is a major cause of the loss of ships, tankers and other marine vessels, resulting in pollution of oceans, seas and coastal waters, loss of life or long delays while repairs are carried out. Each year, dozens of ships sink – many as a result of leaking structures due to corrosion and poor weld quality.

Most of the inspection techniques used today have proven to be disruptive to the manufacturing process and are far from cost effective. New generations of ships are being built from thinner section steels in order to lower the cost of build and ship operations and so typical assessment methods are not as effective as they were for thicker sections. Therefore, there is a genuine need for a more reliable, faster, cost effective and safer inspection technique.

By combining ultrasonic phased array, electromagnetic ACFM (Alternating Current Field Measurement) and laser optical methods, X-Scan enables the detection and sizing of surface breaking and sub-surface flaws or defects. By developing laser-based tracking and a self-controlled robot, X-Scan enables automatic inspection following the weld run.

Alvin Chong, X-Scan Project Leader and Research Fellow at the Brunel Innovation Centre comments: “The scanCONTROL 2700-100 has been very reliable and is a critical part of the X-Scan system. First, it provides very high resolution measurements that we require in order to successfully detect small weld defects, which may measure just a few millimetres in diameter, or even down to a few microns if the defect is a weld crack or notch.”

“Second, the scanCONTROL sensor outputs the profile measurement data to the X-Scan’s robot control system for guidance purposes. This is very important too, as we need the robot to accurately follow the centre of the weld line at all times. The robot cannot be allowed to deviate from this centre line, otherwise the ultrasonic and ACFM inspection systems will not be effective,” he adds.

The research leading to these results has received funding from the European Union’s Seventh Framework Programme managed by REA-Research Executive Agency (FP7/2007-2013) under grant agreement no. 283284. The X-Scan Consortium comprises seven collaborators from four member states, including three SMEs, each representing a different EU country. The seven members are TWI Ltd (UK), Brunel University (UK), Innora Robotics and Automation Ltd (Greece), Vermon S A (France), Spectrumlabs (Greece), Technitest Ingenieros SL (Spain) and Lloyd’s Register EMEA (UK). For the X-Scan project, Innora was the RTD provider (designer and manufacturer of the robot).

At present, X-Scan can be used for automatic inspection of ships in dry dock. However, the system could be expanded and further developed to include a marinised robot, for example, and by adding extra inspection techniques.

X-Scan is suitable for new and old builds. The device enables the volumetric inspection of thin gauge welds and consequently the detection of surface breaking and sub-surface flaws such as porosity, lack of weld penetration, lack of fusion, cracking, etc.

By combining three inspection techniques into a single automatic inspection system saves considerable time and money. In addition, the system eliminates both the need for working at height, and the need for high-risk radiography equipment. Although the system is a prototype, the developers are working on making it more compact and user-friendly. Even in its current form, the system provides defect imaging and analysis at much greater speed and convenience than currently exists.


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