Fraunhofer-Publica

The Fraunhofer-Publica has been successfully documenting the research results of the Fraunhofer Gesellschaft for over 30 years. The platform enables the collaborative linking of research-relevant objects and disseminates within the international scientific community.

The Fraunhofer-Publica thus fulfils its responsibility to promote the transfer of knowledge and know-how to industry and society.

Categories

261122

Research outputs

As an application-oriented research organisation, Fraunhofer aims to conduct highly innovative and solution-oriented research - for the benefit of society and to strengthen the German and European economy.

13735

Projects

Fraunhofer is tackling the current challenges facing industry head on. By pooling their expertise and involving industrial partners at an early stage, the Fraunhofer Institutes involved in the projects aim to turn original scientific ideas into marketable products as quickly as possible.

8040

Researchers

Scientific achievement and practical relevance are not opposites - at Fraunhofer they are mutually dependent. Thanks to the close organisational links between Fraunhofer Institutes and universities, science at Fraunhofer is conducted at an internationally first-class level.

77

Institutes

The Fraunhofer-Gesellschaft is the leading organisation for applied research in Europe. Institutes and research facilities work under its umbrella at various locations throughout Germany.

Recent Additions

  • Publication
    Source Management in DC-Microgrids: An Industrial Application
    ( 2023)
    Bianchini, Isabella
    ;
    Knapp, Jonas
    ;
    Riethmüller, Simon
    ;
    Kwiatkowski, Thorben
    ;
    Yang, Xiaotian
    ;
    Sauer, Alexander
    Industrial direct current (DC) microgrids offer multiple advantages for production factories. They enable higher energy and resource efficiency not only for the production energy supply but also for integrating renewable energy resources. The basic control method of DC microgrids, namely droop control, fits the industrial application due to its decentralized and robust nature. However, in the case of droop control, the DC bus voltage deviates from the nominal value for slowly fluctuating load situations. For this reason, an additional control level for voltage restoration, called secondary control or source management, is necessary. This paper presents hierarchical control for voltage restoration in industrial DC microgrids. The control shifts the current supplied to the DC bus in case the load increases over or decreases below a defined voltage band for a certain period. In addition, the designed control is tested on a real industrial DC microgrid which includes typical industrial loads of up to 50 kW, such as robots of different sizes and CNC machine tools. The control performance with different parameters of the source management is assessed. The results show that the designed control restores the voltage level without creating instabilities in the microgrid for all tested scenarios.
  • Publication
    Efficient piezoelectric gimbal-less MEMS-mirror with large design flexibility
    ( 2023)
    Wysocki, Lena
    ;
    Ratzmann, Lars
    ;
    Schütt, Patrick
    ;
    Albers, Jörg
    ;
    Wille, Gunnar
    ;
    Gu-Stoppel, Shanshan
    Biaxial resonant MEMS-scanners are considered as promising core-device in state-of-the-art imaging and projection systems due to their compactness, the large field-of-view, high speed, and comparably low power consumption. However, the usage in three-dimensional LIDAR modules or projectors for industrial applications is often limited by non-optimal Lissajous-scanning patterns. To achieve dense and spatially uniform Lissajous-trajectories, a suitable frequency ratio of the two oscillation modes is essential. In previous works, the frequency ratio was either maximized or minimized, which often led either to mechanical fragility or undesirable coupling of the two normal modes. For solving the abovementioned problems, a piezoelectrically-driven biaxial MEMS-scanner exhibiting large design flexibility, enabling the individual tailoring of the two orthogonal rotational oscillation-modes and Lissajous-patterns with large fill factor, was developed. This design freedom and decoupling of two axes motions are achieved by a gimbal-less design with individual actuator systems for the two oscillatory axes. Driven by the CMOS-compatible piezoelectric Al(Sc)N, the Q-factor of the resonant mirror with large optical aperture of 5 mm is enhanced by hermetic wafer-level glass-encapsulation. A projection module, which combines the biaxial MEMS-scanner, an RGB-laser-beam combiner, and the electronics for both read-out and control, was developed in the frame of a funded research project ("MEMS-scanner-based laser projection system for maritime augmented reality"). The target of the project was the development of a smart window, in the sense of a MEMS-scanner-based laser projection system for maritime augmented reality, which offers the possibility to fade in safety-relevant information of navigation and ship sensors into the field-of-view of the bridge personnel on the ship’s bridge. Such projector is promising also for further applications in industry, for instance in 3D cameras.
  • Publication
    Dynamics of Development of Laser-Induced Structures on the Surface of a Titanium Alloy
    ( 2023)
    Fomicheva, Iana
    ;
    Druzhinin, Petr Ya
    ;
    Amler, Hans
    ;
    Schuesslbauer, Wolfgang
    ;
    Christiansen, Silke
    ;
    Leuchs, Gerd
    We investigated the dynamics of LSFL (Low Spatial Frequency LIPSS) evolution on the titanium alloy surface. To create them, 12 W picosecond 1.064 μm laser with a pulse repetition rate from 50 kHz to 500 kHz was used. For different laser repetition rate (500, 150, 100 and 50 kHz), the ranges of LSFL periods and peak Fluence of pulse (Fp) for which the maximum period is reached were determined. We also determined the laser parameters at which the resulting LSFL have good quality and uniformity, regardless of the initial surface roughness.
  • Publication
    Efficient Beam Search for Initial Access Using Collaborative Filtering
    ( 2023)
    Yammine, George
    ;
    Kontes, Georgios
    ;
    Franke, Norbert
    ;
    Plinge, Axel
    ;
    Mutschler, Christopher
    Beamforming-capable antenna arrays overcome the high free-space path loss at higher carrier frequencies. However, the beams must be properly aligned to ensure that the highest power is radiated towards (and received by) the user equipment (UE). While there are methods that improve upon an exhaustive search for optimal beams by some form of hierarchical search, they can be prone to return only locally optimal solutions with small beam gains. Other approaches address this problem by exploiting contextual information, e.g., the position of the UE or information from neighboring base stations (BS), but the burden of computing and communicating this additional information can be high. Methods based on machine learning so far suffer from the accompanying training, performance monitoring and deployment complexity that hinders their application at scale.This paper proposes a novel method for solving the initial beam-discovery problem. It is scalable, and easy to tune and to implement. Our algorithm is based on a recommender system that associates groups (i.e., UEs) and preferences (i.e., beams from a codebook) based on a training data set. Whenever a new UE needs to be served our algorithm returns the best beams in this user cluster. Our simulation results demonstrate the efficiency and robustness of our approach, not only in single BS setups but also in setups that require a coordination among several BSs. Our method consistently outperforms standard baseline algorithms in the given task.

Most viewed