SheaRIOS Project Laboratory Trials Performed at TWI
The SheaRIOS Project
TWI is part of the Horizon 2020-funded SheaRIOS Project consortium researching the deployment of robotically applied shearographic inspection equipment on wind turbine blades (WTB). Through the use of robotics and shearography, the project is creating a safer, easier, faster, and more accurate inspection solution compared to currently applied methods.
The system uses a robotic climber that ascends the wind turbine tower and releases a remotely controlled robotic crawler on to the surface of the blade. The crawler utilises a vacuum tread system to transverse the blade’s surface until it reaches an area of interest. Once in position the crawler is secured to the blade using suction cups and the shearographic inspection performed. The inspection data are transmitted to a ground station, where the results can be reviewed.
The SheaRIOS project is now drawing towards its conclusion, with final on-site trials planned for summer 2021. To this end, laboratory integration trials of the crawler robot, shearographic inspection unit and base station were undertaken at TWI in April 2021. The equipment was evaluated on a section of WTB with artificially introduced defects.
SheaRIOS Project Robotic Inspection Trials
TWI Laboratory Trials
Navigation and Capability
During an on-site inspection, the robotic crawler must be able to navigate across a WTB and perform a shearographic inspection to find defects. To demonstrate capability, the robotic crawler was successfully driven to specific points on the test blade and artificial defects identified at these locations.
During the field trials planned for later in the year, the system will be deployed on operating WTBs, where it will not be known whether defects are present, or not. To demonstrate that the inspection system can operate on a ‘live’ WTB, which is subject to vibration and movement, the robotic crawler will carry an additional ‘defect payload’ comprising a section of blade material with artificial defects. The defect payload will be suctioned to the WTB surface, so that it moves in harmony with the WTB during an inspection. The ability to find the artificial defects in the payload will demonstrate that the system is capable of finding defects in a ‘live’ WTB.
The test panel was successfully attached to the SheaRIOS crawler and navigated around the blade. Under simulated inspection conditions, with random movements applied to the blade, artificial defects were identified in the panel indicating the system’s capability to handle the types of blade motion expected on a ‘live’ WTB.
Effect and Prevention of Light Pollution
The shearography system uses green laser light that can be over-exposed by bright sunlight, preventing interpretation of the results. Consequently, a light shield was developed and attached to the crawler to block out the unwanted ambient light. It was demonstrated that with minor modifications, the light shield was able to conform to the WTB’s surface and reduce the light levels within the hood to an acceptable level.
The TWI-based laboratory trials successfully demonstrated:
- The robotic crawler can navigate around the test blade with ease
- The SheaRIOS system can detect defects in WTBs
- The inspection system can function on a non-stationary WTB
The project consortium will continue to work together to enhance the SheaRIOS system ahead of the field trials scheduled for this summer on an operational wind turbine.
The SheaRIOS Project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 780662
Senior Project Leader
James graduated from Sheffield University with a B.Eng and PhD in 1992. He worked as a metallurgist at Sandberg Consultant Engineers, as a senior technologist at Rolls Royce and as chief materials scientist at APPH (now Heroux Devtek), before joining TWI in 2014. He first specialised in hot forming and bonding processes before transferring to the NDT group.
He has successfully led numerous collaborative (Horizon 2020 and Innovate UK) and single client projects, leading research activities and developing manufacturing prototypes. Current areas of interest include shearography, radiation effects on materials and sensors, geothermal energy, ATEX, and manufactured defects for calibration purposes.