Continuum robot offers brand new possibilities

The Center of Competence for turbines and MRO at Leibniz Universität Hannover.

05.2017 | Text: Silke Hansen

Text:
Silke Hansen schreibt als freie Journalistin für den AEROREPORT. Seit über zehn Jahren berichtet sie aus der Welt der Luft­fahrt, ihre Themen­schwer­punkte sind Technik, Innovation und Markt. Ein weiteres Spezial­gebiet der Autorin ist das Corporate Responsibility Reporting.

Like a thin snake or long earthworm, the robot skillfully slithers its way through the engine—from the front, in between the fan blades, and then deeper into the engine’s inner workings. Is this the future of engine repair?

Scientists at Gottfried Wilhelm Leibniz Universität Hannover believe it is. They are researching this completely new method at the Center of Competence for turbines and Maintenance, Repair & Overhaul (MRO), which was founded as part of a scientific alliance with MTU Aero Engines. The miniature robot has a bionic structure inspired by nature—elephant trunks, snakes and tentacles in particular, according to Professor Jessica Burgner-Kahrs. The little helpers that she and her team developed are called continuum robots in the technical jargon because of their ability to function without any joints. Not only do they have the potential to improve minimally invasive surgical procedures in the field of medicine, they also offer brand new possibilities for inspections and repairs in engine maintenance.

Leibniz Universität Hannover

Today there are more than 25,000 students enrolled at Gottfried Wilhelm Leibniz Universität Hannover (Leibniz Universität Hannover for short; formerly University of Hannover), pursuing studies in the natural sciences and engineering, the humanities and social sciences, law and economics. The university offers courses in around 90 different subjects, with a distinct leaning toward scientific and technological disciplines. Student numbers increased significantly in the 1970s, when urgently needed teacher training courses were added to the university’s curriculum.

Leibniz Universität Hannover is a member of TU9 German Institutes of Technology e.V., an alliance of Germany’s nine leading technical universities.

Dr. Bertram Kopperger, the head of manufacturing and MRO technology management at MTU, oversees this project: “In contrast to rigid borescopes, the ‘robot’ is much more flexible.” Plus: In conventional borescoping, engineers can access the engine only from certain borescope bosses on the side and the openings are not particularly large. Scientists from Universität Hannover want to develop a first-generation robot with the necessary stability by 2020. Experts at MTU are working in parallel on three different tool attachments— for example, to polish blades or rework coatings. MTU Maintenance provides the modules for testing. “This project is a trailblazer,” says Kopperger. Fly-by-hour contracts, in which the airline pays fixed maintenance rates per flight hour for its engines, are becoming more popular in the aviation sector. Fast, flexible repair solutions are gaining in importance. The robot could do its job while the engine is still mounted on the wing or is at least standing near the aircraft.

(strich:Record performance) The record for the smallest continuum robot is currently held by a device measuring between 0.8 and 2.5 millimeters in diameter. Hover over the image for a bigger view

Record performance The record for the smallest continuum robot is currently held by a device measuring between 0.8 and 2.5 millimeters in diameter.

CTCR

Record performance The record for the smallest continuum robot is currently held by a
device measuring between 0.8 and 2.5 millimeters in diameter.

(strich:Repair without disassembly) The robot arm can access the blades of all turbine stages. Hover over the image for a bigger view

Repair without disassembly The robot arm can access the blades of all turbine stages.

Metabot1

Repair without disassembly The robot arm can access the blades of all turbine stages.

(strich:Collaboration) The Turbine and MRO Center of Competence is a collaborative project. Hover over the image for a bigger view

Collaboration The Turbine and MRO Center of Competence is a collaborative project.

Labor3

Collaboration The Turbine and MRO Center of Competence is a collaborative project.

(strich:In the lab) Students at Leibniz Universität Hannover develop engine repair technologies. Hover over the image for a bigger view

In the lab Students at Leibniz Universität Hannover develop engine repair technologies.

Labor2

In the lab Students at Leibniz Universität Hannover develop engine repair technologies.

Collaborative research into the “regeneration of complex capital goods”

Among other things, this project—which is a part of the Collaborative Research Centres (CRC) of the German Research Foundation DFG—is jointly funded. Assigned the CRC code 871, it deals with the “regeneration of complex capital goods.” “The close interdisciplinary cooperation between various institutions of Universität Hannover and the Technische Universität Braunschweig means several chairs are pooling their expertise,” says Professor Jörg Seume, Head of the Institute of Turbomachinery and Fluid Dynamics (TFD) at Universität Hannover. His institute is responsible for this CRC and has been MTU’s university partner for about 20 years; joining the Center of Competence for turbines and MRO in 2008. Munich values the high level of professional competence in the field of continuous-flow machines offered in Hannover. Its proximity to the headquarters of MTU Maintenance at Hannover Airport was another reason to establish the Center of Competence (CoC) for turbines and MRO here.

Scientists are also carrying out important fundamental research on turbines. A key strength is their thematic range, encompassing aerodynamics, aeroacoustics, aeroelastics and numerical methods for calculation and simulation. In addition, within the mechanical engineering faculty, there is a close research collaboration with the institutes for manufacturing and turbomachinery, according to Seume.

The technical equipment is also very impressive: the TFD alone offers three test rigs for testing, one of which is a completely new turbine test cell. Companies including MTU, Siemens, MAN and Volkswagen rely on this scientific know-how. According to one of the scientists, the collaboration with MTU is very intensive and productive. Currently, the engine manufacturer has placed six ongoing projects at the CoC, with six more currently at the planning stage for 2017 and 2018.

Video: New possibilities for engine maintenance Article with video

New possibilities for engine maintenance

Continuum robots function without any joints. They offer brand new opportunities for inspections and repairs in engine maintenance. To the video ...

From higher vocational school to a TU9 member

Leibniz Universität Hannover was founded in 1831 as a higher vocational school with 64 students and 14 subjects—and mechanical engineering was one of them from the very beginning. Today the university is a member of TU9, an alliance of leading German technical universities. Along with five other universities and research institutes in Germany as well as the materials and structural mechanics cluster, it is also a partner of MTU, who has founded a joint Center of Competence with each of them. “In this way, we can put selected universities and research institutes in a position to meet our needs and requirements,” explains Kopperger. “It ensures MTU’s ability to innovate, strengthens the networking between science and industry, and helps us attract young academic talent to the company.”

However, these collaborations are by no means a one-way street. Seume values them highly: “We can mutually exploit our skills and learn from each other.” There are numerous advantages to this reciprocal exchange of knowledge. “We’re working with MTU on cutting-edge technologies.” After all, for mechanical engineers, an aircraft engine is the supreme discipline: it is hot, under heavy load and constantly vibrating. It calls for the development of complex methods and long-term solutions. Or, as a scientist at the mechanical engineering faculty in Hannover puts it: “It takes a lot of brain power.”

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