Made-to-measure rotor blades

Rotor blades for wind turbines are a core business activity of the Magdeburg-based wind power plant manufacturer Enercon. Highest standards of quality and dimensional stability are applied to their production, a factor which has an influence not only on the further processing and assembly of the rotor blades, but also on the efficiency of the entire wind turbine. A reliable quality control throughout the entire production process is therefore essential. Measurement of the rotor blade flanges, the sensitive interface between rotor blade and hub, is carried out with AICON‘s portable coordinate measuring machine MoveInspect DPA.

Advanced technology made in Germany

For over 25 years, Enercon has been technology leader in the wind energy industry. Quality and innovation are the main critical success factors of Enercon‘s corporate strategy. A strong vertical integration and comprehensive quality management system also ensure that high quality standards are maintained. With the mission to always deliver mature products with cutting-edge technology to customers, all Enercon system components are subjected to a continuous development process. A large staff of design engineers ensure close interdisciplinary cooperation with all company areas. Together they set technological standards for new system generations, thus strengthening the position of Enercon as Germany‘s market leader.

Extensive simulation and test stations in the Enercon Research Center help to ensure extensive testing of new system components in the preliminary stages. Customers can therefore count on reliable system technology at the highest quality standards.

Flange measurement in production – a challenge

The manufacture of rotor blades is carried out in different steps. The flanges have a diameter of up to three meters. When machining the flange, the flatness of the flange must be checked directly on the machine tool. The space available for the flange measurements is about 5 x 8 m.

So far, the problem was solved with a laser tracker. For the measurement, the rotor blade had to be run back inside the machine and probed at about 100 measurement points with a hand-held reflector from a ladder. Here, the biggest challenge was that exactly the same position had to be restored in order to carry out further processing steps. The measurement itself lasted well over an hour.

Enormous time and cost advantage thanks to AICON‘s DPA

Since the beginning of 2014, the portable coordinate measuring machine MoveInspect DPA is being successfully used at Enercon. For this particular measurement task, AICON expanded its system by a further component. A high resolution digital camera acts in conjunction with a projector to project a point grid on the component to be measured. This allows the measurement to be made directly in the processing machine, without changing the blade position. Targets are also projected, so that manual probing is not necessary.

The flange is photographed from different directions with the digital camera, covering all relevant areas. The digital images are processed in the evaluation computer and the 3D coordinates of the targeted points are automatically calculated. The measurement of the flange takes about 20 minutes. A 75 percent time saving compared to measurements with the laser tracker! In addition, the rotor blade can be processed immediately – another time and cost advantage.

Andy Arndt, head of quality assurance, is responsible for the project at Enercon and is very happy with the choice of AICON‘s DPA: „With the hand-held DPA we are able to perform fast 3D measurement of our flanges. In addition to the speed, measurement within the processing machine is another great advantage. In the past we had to change the position of the blade for the measurement and then restore it. This is a very time consuming process, which can now be omitted thanks to AICON‘s DPA. The short measurement times enable us to use the DPA for further measurement tasks in the future.“

Enercon plans to carry out other production tasks with AICON‘s measuring system. These measurement tasks do not necessarily have to be made with the projection technique – it is also possible to work with targets. To keep the cost of consumables low and flexibility high, Enercon can use a special feature of the AICON software: the CodeMaker module, which allows users to create their own targets.

The DPA of AICON is therefore above all a longterm measurement solution for Enercon. The mobile system is versatile and can be tailored to the individual measuring tasks of the company. A universal solution!

We give thanks to  ENERCON GmbH in Magdeburg for their friendly support.