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Klocke F.,RWTH Aachen | Brummer C.M.,Fraunhofer Institute for Production Technology
Procedia Engineering | Year: 2014

A new laser integration into a spinning machine was developed offering the flexibility to apply completely new processing strategies for laser-assisted multi-pass metal spinning. In this process the formability of challenging materials is improved by selective heating of the forming zone by means of laser. In order to decrease the strength and increase the formability of titanium (grade 2) experimental investigations have been performed to generate a suitable temperature field in the workpiece. © 2014 The Authors. Published by Elsevier Ltd.

Pohlmann U.,Fraunhofer Institute for Production Technology
WCOP 2013 - Proceedings of the International Doctoral Symposium on Components and Architecture | Year: 2013

The number of software components within a cyber-physical systems increases continuously. However, not all components are needed at all time. Because of structural changes of software and hardware it is possible to use resources more efficiently. For example, energy is saved by shutting down currently not needed ECUs. Software component instances (SCIs) must be deployed to an electronic control unit (ECU) to be executed. A safe deployment must consider the changes of the software and hardware structure. State-of-the-art deployment algorithms like [14] are not designed for reconfigurable software applications and reconfigurable hardware platforms. This paper presents first ideas how to specify reconfigurable hardware platforms and how to consider software and hardware changes for a safe deployment at design time. We demonstrate the properties of our deployment approach for reconfigurable cyber-physical systems by using Lego mindstorms robots. Copyright © 2013 ACM.

Frank S.,Fraunhofer Institute for Production Technology
Journal of Materials Processing Technology | Year: 2015

Joints between aluminum and galvanized steel pose a challenge for current manufacturing technologies. A hybrid joining method, which combines a pulsed and a continuous laser beam in a single process, has been identified as a potential solution for this challenge. The feasibility of this approach is verified by joining different base material alloys using zinc- and aluminum-based consumables. It is shown that the double beam method can be applied to different joint geometries by joining both double-flanged joints and lap joints. An analysis of the joint microstructure using metallographic cross-sections and transmission electron microscopy shows that intermetallic compounds can be limited to non-critical amounts. Tensile tests show that joint strengths in excess of 150 MPa can be achieved for both types of joint geometries. When shear loads are applied, the use of aluminum-based consumables leads to superior strength. © 2015 Elsevier B.V. All rights reserved.

Hunten M.,Fraunhofer Institute for Production Technology
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Miniaturization and integration are the dominating factors for the success of numerous optical devices. Conventional manufacturing processes for the fabrication of precise glass optics by means of grinding and polishing cannot cope the increasing demands in terms of precision, volume and costs. Here, precision glass molding is the enabling technology to meet these demands of the future optical products and applications. Since the market requests further miniaturization and integration of the micro optical components the possession of the entire sequence of processes is absolutely essential. With the accomplished and ongoing developments at the Fraunhofer IPT, the replication of double-sided (a)spherical and (a)cylindrical glass lenses with form accuracies of < 150 nm as well as lens arrays and even freeform optics could be realized. Therefore, a sequence of processes needs to be passed. The FEM-simulation of the molding process which was driven to a point capable to simulate even the molding of freeform optics is the first process step. Further on, new mold design concepts were generated to enable the replication of free formed optics. The research works focusing on the mold manufacturing led to sophisticated grinding process strategies able to realized complex mold geometries such as lens arrays. With regard to the coating of the molds, proceedings were developed assuring a defect free and uniform coating which enables the longevity of the molds and therewith helps reducing the final costs per lens. Thus, the precision glass molding becomes more and more interesting even for highly complex mid volume lots, characteristic for European or US optics manufacturer. © 2010 Copyright SPIE - The International Society for Optical Engineering.

Surgery is unavoidable for treating inner ear tumors, but the inner ear is difficult to access. This is because it is covered by a cranial bone known as the mastoid, or petrosal bone. What's more, the surrounding tissue contains lots of nerves and blood vessels. For this reason the surgeons will cut out as much of the mastoid bone as needed until they have located each one of these sensitive structures. Only then can they be sure not to damage them. What this entails most of the time is the removal of the entire bone. The hole thus created is filled in with fatty tissue taken from the abdomen after the completion of the procedure. In the future this operation will be performed in a less invasive fashion, requiring just a small hole measuring 5 mm in diameter through which the tumor can be resected from the inner ear. The technology that makes this possible goes by the name of NiLiBoRo, a German acronym which stands for "Non-linear Drilling Robot". The system is being developed by researchers in the Mannheim Project Group for Automation in Medicine and Biotechnology, part of the Fraunhofer Institute for Production Technology and Automation IPA, in cooperation with the Technical University of Darmstadt, the University of Aachen, and the Düsseldorf University Clinic. Drilling machines capable of boring a tunnel through bone already exist, but they can do so only in a straight line. "NiLiBoRo is the first one that can drill around corners as well," says project group scientist Lennart Karstensen. It is this particular characteristic that makes it possible to perform minimally invasive surgery on inner ear tumors. If the tunnel were to run in a straight line, it would at times come troublingly close to hitting nerves. To avoid injuring nerve tissue, the tunnel would have to be no more than 1 to 2 mm in diameter. However, it is impossible to perform surgery through such a small opening. The NiLiBoRo on the other hand is capable of steering around sensitive areas. This makes it possible to achieve a tunnel diameter of 5 m, which is wide enough to perform the operation. Hydraulic lines allow the robot worm to crawl forward So how does this "worm" manage to drill around curves and corners through the mastoid bone? "The worm consists of a 'head' and a 'tail' section," explains Karstensen. "Both of these parts are connected with one another by means of a flexible bellows mechanism." The design is reminiscent of an articulated public transit bus in which the front and rear sections are coupled by means of a hose-like center section that looks like an accordion. As it travels through the bone, the robot is connected to the "outside world" – in other words the control units and pumps in the operation room – by means of 8 to 12 hydraulic lines. It is these lines that allow the robot to crawl forward in the right direction. This is done by first pumping hydraulic fluid into three bladders found in the rear section of the robot. The bladders fill in the empty space between the worm and the bone and thereby fix the rear section of the robot in place. The hydraulic fluid then travels into the bellows. This causes the "accordion" to expand, which pushes the head forward. The worm stretches, so to speak, and presses its front section further into the bone. The drill attached to the head bores deeper inward. Now the rear section retracts towards the head in a motion similar to that of a real worm. To do so, the bladders in the front section are pumped full of fluid to hold the front in place while the fluid in the rear bladders is evacuated. At this point the fluid is also being sucked out of the bellows through the hydraulic lines. The robot contracts, which pulls the rear section up behind the front. In this way the NiLiBoRo makes its way forward bit by bit. "We can alter the robot's direction of travel by adjusting the bladders in the front section. For instance, if we wanted to move left then we fill the left bladder with less fluid than the right, which will cause the robot to veer to the left," says Karstensen. In the laboratory, and later in the operation room, the path the NiLiBoRo takes as it drills its way forward is precisely monitored by an electromagnetic tracking system, or EMT for short. Designed by partners at the Technical University of Darmstadt, this system works by sporadically capturing images of the robot using computer tomography in order to monitor its position. Researchers have already constructed an initial prototype of the NiLiBoRo, which is currently five times larger than the planned final version. Right now it is composed of only the forward section together with the heart of the machine, the bellows. The developers plan to continue optimizing and expanding the prototype piece by piece. Once all the technology has been developed, the NiLiBoRo will be shrunk down to its final size. Researchers hope to have the miniature robot ready for testing by physicians in two years.

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