04/05/2019

Automated Inspection System for Offshore Wind Power Plants

Offshore wind power plants are an important pillar for the energy transition, as they can reach a very high capacity of more than four thousand full load hours per year. However, like any other structure, they have to undergo regular maintenance and inspection.

To this day, some of these tasks are still carried out by divers, which is very time-consuming and dangerous. The use of remotely operated underwater vehicles (ROVs) has been increased in the last years but is almost exclusively limited to video-based procedures or the use of sonars. Therefore, a detailed damage detection is usually not possible. The additional support provided by maritime information and robot technology represents a significant step forward for their inspection.

Flexible sensor carrier for detailed analysis tasks

The new MISO inspector (multi input single output) sensor carrier is the perfect tool for this purpose. It is a multivariate inspection and analysis system. Completely flexible and thus adapted to different tasks, various sensors can be docked to it. Their combination can carry out inspection tasks under or above water using ROVs or other robotic carriers. In addition to the existing sensor technologies that can be used in the MISO-Inspector, novel sensor technology for use under water will also be developed and evaluated.

This includes a novel hyperspectral camera. It enables a non-contact detection, differentiation and analysis of materials. Since it is difficult to nearly impossible for engineers to distinguish rust or other damages from vegetation, dirt etc. using only underwater pictures, the hyperspectral camera can open up completely new possibilities for the identification of damages.

Automated and self-learning report generation

The central component of the MISO-Inspector is the "multivariate signal analysis". According to the principle of "multiple input - single output", data from different sensors are processed and merged for a complete damage analysis. "In only one dive, the 3D model of the structure can be compared with the SHM data (structural health monitoring) and the test results of different, complementary sensors can be evaluated in advance. The inspection results are then marked locally on the digital 3D model. This is a significant increase in efficiency compared to the inspection techniques currently in use," adds Andreas Nuber of Wölfel Engineering GmbH + Co. KG.

Should a detected position require further clarification, the MISO inspector can approach these locations again and examine them more closely. The system learns from the decisions made by engineers through innovative, self-learning algorithms.

Summary

Flexible sensor carrier for multivariate inspections and analyses under and above water
Contactless investigation of findings and identification of the chemical composition of surfaces
Industry 4.0 approach: Fusion of data from various sources into a digital model enables novel and innovative damage detection in combination with “supervised learning”

By combining the individual technology components, an intelligent inspection system, the MISO Inspector, is created. It enables the automated inspection of offshore plants and at the same time reduces the workload and the risks of human operations significantly. This research project is supported by the Federal Ministry of Economic Affairs and Energy with a sum of 1,838,000 €. Wölfel Engineering GmbH + Co KG is leading the consortium of the project.