In the non-circular rolling, the feasibility of rolling several mutually offset, locally non-round shaped elements into a cylindrical semi-finished product are investigated. One sub-area of the investigations is the rolling of two elliptical sections.
From three different calculation concepts for the determination of the tool engraving, one was chosen for a simulative parameter study. The main influencing variables, including the length and width of the engraving and a process window, were identified.
forming technology, manufacturing technology, FEM
Forming technology Jagodzinski, A.; Rasch, J.; Kriwall, M.; Stonis, M.; Behrens, B.-A.: Inhomogene Rohteilerwärmung – Einfluss der Länge des Temperaturgradienten auf die Materialeinsparung durch inhomogene Rohteilerwärmung bei der Warmmassivumformung. In: stahl + eisen, Maenken Kommunikation GmbH (2022), H. 10, S. 45-48. ISSN: 0340-4803.
In order to make the production of complex geometries as efficient as possible, several forming stages are generally used. In these, the billet is first heated homogeneously and then forged via several preliminary and intermediate stages as well as final forming. Previous investigations have shown that significant material savings can be achieved by using inhomogeneous, rather than homogeneous, billet heating. A limiting factor in the practical implementation of inhomogeneous heating is the temperature gradient between the hot and warm regions of the billet.
This study therefore investigates the influence of the length of the temperature gradient on the blank size required to achieve form filling for a given finished part geometry. For this purpose, a simulative parameter study was carried out with three temperature transitions of different lengths and two different finished part sizes.
It was shown that, depending on the finished part size and the length of the temperature gradient, between 3.31% and 17.49% material can be saved compared to a homogeneously heated billet. The length of the temperature gradient thus has a significant influence on the material savings potential.
bulk forming, inhomogeneous heating, resource efficiency, FEA
Industry 4.0 Jütte, L.; Poschke, A.; Küster, B.; Overmeyer, L.: Quantitative performance evaluation in an augmented reality view enhancement driver assistant system. In: Proceedings Volume 12226, Applications of Digital Image Processing XLV; 1222617 (2022), SPIE Optical Engineering + Applications, 2022, San Diego, California, United States of America. DOI: https://doi.org/10.1117/12.2633264.
The temporally and spatially accurate display of information in augmented reality (AR) systems is essential for immersion and operational reliability when using the technology. We developed an assistant system using a head-mounted display (HMD) to hide visual restrictions on forklifts. We propose a method to evaluate the accuracy and latency of AR systems using HMD. For measuring accuracy, we compare the deviation between real and virtual markers. For latency measurement, we count the frame difference between real and virtual events. We present the influence of different system parameters and dynamics on latency and overlay accuracy.
augmented reality, image processing, driver assistance system, forklift trucks
Additive Manufacturing Rathje, A.; Witt, R.; Knott, A.-L.; Küster, B.; Stonis, M.; Overmeyer, L.; Schmitt, R. H.: Quality Monitoring Procedure in Additive Material Extrusion Using Machine Learning. In: Software Engineering and Formal Methods. SEFM 2022 Collocated Workshops. Springer International Publishing. Jg. (2022), S. 93–102. https://doi.org/10.1007/978-3-031-26236-4_8.
Additive manufacturing enables the economical production of complex components with a high degree of customization. Therefore, the medical industry is using the advantages of additive manufacturing to produce individualized medical devices. Medical devices are subject to special quality control requirements that additive manufacturing processes do not meet yet. This article deals with the introduction of an in situ process monitoring concept using the example of fused deposition modeling. The process monitoring is carried out by a quality model, which accesses the data of a self-developed sensor concept integrated in the printer. This data is analyzed using a machine learning pipeline to predict process and product quality. Thereby, the machine learning pipeline consist of several sequential steps, ranging from data extraction and preprocessing to model training and deployment. The procedure presented for ensuring print quality forms a basis for the production of safety-relevant components in batch size one and extends conventional quality assurance methods in additive manufacturing.
additive manufacturing, quality monitoring, fused deposition modeling, artificial intelligence
Process monitoring strategies allow wear-related conditions of forging dies to be detected and predicted. The prediction of the wear condition allows intelligent maintenance strategies. This allows residual tool life to be fully utilized, scrap to be reduced and downtime to be calculated. The content of this article is an economic analysis for calculating the payback period of a process monitoring system.
forging, process monitoring, economic efficiency
During flat die rolling, two die plates pass each other and form the cylindrical semi-finished product enclosed within. Non-circular rolling examines the rolling of multiple, locally nonround geometries such as eccentrics. With the aid of statistical experimental design, a simulative parameter investigation has been carried out, main influencing variables have been recognised and process windows identified.
non-round, eccentric, flat jaw tools, preforms, intermediate forms, FEM
How can additively manufactured components be laser welded? Their layered structure makes the welding process more complicated than for conventionally produced parts. IPH and LZH are jointly researching how components can nevertheless be joined in a quality-assured manner.
Additive manufacturing, 3D printing, laser transmission welding, joining, quality
In manual solid forming, hand-guided forging tongs are used when processing forged parts. During the forging process, employees are physically stressed by high forging part weights and transmitted impacts. This physical stress leads to employee health limitations and increases absenteeism rates. Ergonomic forging tongs have been developed at IPH that lead to a relief of the forging employees.
ergonomics, forging tongs, forming technology, prevention
Factory planning, Artificial Intelligence Seel, A.; Kreutzjans, F.; Küster, B.; Stonis, M.; Overmeyer. L: Deep Reinforcement Learning Based UAV for Indoor Navigation and Exploration in Unknown Environments. In: 2022 8th International Conference on Control, Automation and Robotics (ICCAR), S. 388-393, DOI: 10.1109/ICCAR55106.2022.9782602.
Factory planning can increase the productivity of manufacturing significantly, though the process is expensive when it comes to cost and time. In this paper, we propose an Unmanned Aerial Vehicle (UAV) framework that accelerates this process and decreases the costs. The framework consists of a UAV that is equipped with an IMU, a camera and a LiDAR sensor in order to navigate and explore unknown indoor environments. Thus, it is independent of GNSS and solely uses on-board sensors. The acquired data should enable a DRL agent to perform autonomous decision making, applying a reinforcement learning approach. We propose a simulation of this framework including several training and testing environments, that should be used for developing a DRL agent.
drone, UAS, deep reinforcement learning
Aurich, P.; Böning, C.; Stonis, M.; Overmeyer, L.: Throughput Analysis for Layout Optimisation of Modular Conveyor Systems. In: Herberger, D.; Hübner, M. (Eds.): Proceedings of the Conference on Production Systems and Logistics: CPSL 2022. Hannover: Institutionelles Repositorium der Leibniz Universität Hannover, 2022, S. 329-329. DOI: https://doi.org/10.15488/12196.
In this paper, objective functions for the optimisation of modular conveyor systems will be introduced. Modular conveyor systems consist of conventional as well as modular conveyor hardware, which are arranged in form of matrix-like layouts. The aim of an ongoing research project is to provide small and medium-sized enterprises with a user-friendly decision support for the selection and planning of modular conveyor systems. For this purpose, the conveyor systems should be evaluated according to the objectives throughput and space requirement. Therefore, mathematical equations have been developed, which enable a fast and precise evaluation of layouts. The paper focuses mainly on the efficient calculation of the throughput. The result quality of the evaluation equations regarding the throughput was proven by a simulation of example systems.
modular conveyor, conveyor system evaluation, throughput analysis, layout optimisation, logistics
Industry 4.0, Production planning Müller, M.; Schüler, F.; Stonis, M.; Nyhuis, P.: Development of a Method for Decision Support on Participation in Capacity Sharing for Manufacturing SMEs. In: Herberger, D.; Hübner, M. (Eds.): Proceedings of the Conference on Production Systems and Logistics: CPSL 2022. Hannover: publish-Ing., 2022, S. 411-423. DOI: https://doi.org/10.15488/12197.
A volatile, non-transparent market environment leads to fluctuations in the load on production capacities in the manufacturing sector, which are reflected within production in the over- or underutilization of machines and persons. Small and midsized enterprises (SMEs) are expecting increasing volatility, which is accompanied by an increase in the frequency of market and economic cycles. For SMEs it is difficult to cope with these fluctuations. Capacity sharing platforms can be a solution for this challenge. Platforms are available in different forms, but not used by companies often, because of prevailing scepticism in different fields. Therefore, a methodology will be developed to provide a decision support for or against platform usage. Additionally, the platform type choice will be supported, and the changes of logistic and economic indicators will be considered. With this information companies can make a qualitative decision, and the existing inhibitions can be alleviated.
capacity sharing, decision support, supplier and consumer view, logistic and economic indicators
The results of the wear investigations will allow multidirectional processes in hot forging to be optimized in the future in a low-wear and economical manner. The determined, wear-inducing process parameters within the design guideline represent elementary basic knowledge which can be applied in a process-specific manner. In principle, the economic potential of multi-directional forging processes using of multi-directional forging processes using sliding dies depends on the application and the desired component geometries. Multi-directional forging processes forging processes offer great potential for savings and can be process design using the results obtained, they can achieve high tool life and have a positive influence on the competitive situation of companies. As a result costs for explicitly selected niche components with significantly higher with significantly increased complexity can be reduced in the future with manageable investment costs in the future. In addition to the process-specific optimization of the process parameters, in the future options for mold design adaptation with regard to local cooling or local cooling or thermal insulation of the slide-wedge wedge mechanics, in order to be able to use the systems in automated series automated series production.
Slide tools, process design, economic efficiency, solid forming
Automation Kutzner, C.; Jurisic, S.; Stonis, M.; Nyhuis, P.; Seiter, M.: Robotergesteuerte Prozessautomatisierung zur softwarebasierten Automatisierung administrativer Prozesse der innerbetrieblichen Lieferkette (RPAlog). In: Logistics Journal, Vol. 2022, ISSN 1860-5923. DOI: https://doi.org/10.2195/lj_NotRev_kutzner_de_202205_01.
The internal supply chain in companies includes all areas from procurement to shipping. It is characterised by a heterogeneous process landscape, often accompanied by repetitive, administrative tasks. These are usually associated with a high level of manual effort and a high potential for errors. An example of this is the manual entry of delivery notes into an enterprise resource planning (ERP) system. Even incremental improvements already help SMEs enormously to cope with the heterogeneity of processes in the internal supply chain. Robotic Process Automation (RPA) is a promising approach to this. RPA offers the potential to automate administrative processes in internal supply chain that previously did not seem automatable.
Logistik, innerbetriebliche Lieferkette, robotic process automation, RPA
Progress is urgently needed in the energy transition - but there are always acceptance problems and lawsuits with renewable energies. In the project "WindGISKI", a geoinformation system based on artificial intelligence is to be developed, which addresses these issues. In a preliminary project, influencing factors within the area of conflict between species, environmental and climate protection have already been identified. An interdisciplinary team from science and industry is now taking the next step with the development of artificial intelligence.
wind energy, area selection, artificial intelligence
Additive manufacturing allows components to be manufactured flexibly. This manufacturing process is particularly suitable for products with a unique character. In the production of large components, which have previously been manufactured by casting, this offers the advantages of greater flexibility in design and the elimination of the need to build molds that are only used once for unique items. To manufacture large components additively, a consortium of five companies is developing a new 3D printer for XXL products. For quality assurance, IPH - Institut für Integrierte Produktion Hannover has implemented two monitoring systems. These capture the geometry using three laser line scanners and regulate the manufacturing process during printing using two different software systems.
XXL products, large components, additive manufacturing, 3D printing, quality control
Forming technology Budde, L.; Prasanthan, V.; Merkel, P.; Kruse, J.; Faqiri, Y.; Lammers, M.; Kriwall, M.; Hermsdorf, J.; Stonis, M.; Hassel, T.; Breidenstein, B.; Behrens, B.-A.; Denkena, B.; Overmeyer, L. Material dependent surface and subsurface properties of hybrid components. In: Production Engineering, doi: 10.1007/s11740-022-01128-9
Tailored forming is used to produce hybrid components in which the materials used are locally adapted to the diferent types of physical, chemical and tribological requirements. In this paper, a Tailored Forming process chain for the production of a hybrid shaft with a bearing seat is investigated. The process chain consists of the manufacturing steps laser hot-wire cladding, cross-wedge rolling, turning and deep rolling. A cylindrical bar made of mild steel C22.8 is used as the base material, and a cladding of the martensitic valve steel X45CrSi9-3 is applied in the area of the bearing seat to achieve the strength and hardness required. It is investigated how the surface and subsurface properties of the hybrid component, such as hardness, microstructure and residual stress state, change within the process chain. The results are compared with a previous study in which the austenitic stainless steel X2CrNiMo19-12 was investigated as a cladding material. It is shown that the residual stress state after hot forming depends on the thermal expansion coefcients of the cladding material.
Tailored forming, Residual stress, Laser hot-wire cladding, Deep rolling, Hybrid Components
The reorganization of factory objects in the restructuring of existing factories is associated with numerous challenges. This article provides an overview of possible conflicting goals and key factors influencing the success of the project.
Factories are subject to continuous change. Ever shorter development cycles in the manufacture of different products lead to an increased need for restructuring of affected manufacturing structures. In the context of factory planning projects, the focus is on the design of the layout under the influence of individual framework conditions. The relocation steps necessary for realization are usually determined only after the layout design has been completed. However, the planning and preparation of the relocation represents an independent project task with regard to the objectives and complexity. Within the scope of the research project on the "Development of a Method for the Optimal Planning of the Relocation of Factory Objects in the Course of the Realization of a New Factory Layout" (OptiFaU), fundamental interrelationships in the planning and execution of factory relocations are investigated and discussed with regard to their significance for the success of the project. The aim of the project is to provide planning persons (e.g. relocation service providers or factory planners) with a possibility to evaluate relocation alternatives.
relocation planning, project planning, scheduling, factory planning, reorganization
IPH has developed an algorithm for the automated design of rolling dies in the DFG project "Non-Circular Rolling". The researchers are using it to perform extensive parameter studies with a wide range of dies.
Non-circular rolling, cross wedge rolling, rolling dies, design, automation, algorithm
For more than half of the approximately 30,000 wind turbines in Germany, the 20-year EEG funding will end in the next ten years. It is still unclear what the optimal technical and economic strategies for end-oflife utilization might look like. The BMWK joint project „TransWind“ aims to analyze the end-of-life issue on a micro- and macro-level in a transdisciplinary manner to support stakeholders from politics, the wind industry, and the resource and recycling sector in the selection of end-of-life strategies.
wind turbines, end-of-life, ecology, dismantling, repowering, disassembly, recycling, XXL products
Forming technology Budde, L.; Biester, K.; Merkel, P.; Lammers, M.; Kriwall, M.; Hermsdorf, J.; Stonis, M.; Behrens, B.-A.; Overmeyer, L.: Investigation of the material combination 20MnCr5 and X45CrSi9-3 in the tailored forming of shafts with bearing seats. In: Production Engineering, DOI: 10.1007/s11740-022-01119-w.
The Tailored Forming process chain is used to manufacture hybrid components and consists of a joining process or Additive
Manufacturing for various materials (e.g. deposition welding), subsequent hot forming, machining and heat treatment. In
this way, components can be produced with materials adapted to the load case. For this paper, hybrid shafts are produced by
deposition welding of a cladding made of X45CrSi9-3 onto a workpiece made from 20MnCr5. The hybrid shafts are then
formed by means of cross-wedge rolling. It is investigated, how the thickness of the cladding and the type of cooling after
hot forming (in air or in water) afect the properties of the cladding. The hybrid shafts are formed without layer separation.
However, slight core loosening occurres in the area of the bearing seat due to the Mannesmann efect. The microhardness
of the cladding is only slightly efected by the cooling strategy, while the microhardness of the base material is signifcantly
higher in water cooled shafts. The microstructure of the cladding after both cooling strategies consists mainly of martensite.
In the base material, air cooling results in a mainly ferritic microstructure with grains of ferrite-pearlite. Quenching in water
results in a microstructure containing mainly martensite.
laser hot-wire cladding, cross-wedge rolling, hybrid components, cladding