Assembling large-scale products involves frequent process interruptions. To reduce the duration of an assembly stop, the WZL of RWTH Aachen University and the IPH Hannover developed an approach which is able to identify alternative assembly plans and to evaluate them on the basis of the logistic performance objectives. Stock, capacity utilization, lead time and adherence to schedule are transferred into costs and assembly plans are thus comparable based on one parameter.
production planning and control, assembly, logistical objectives
Within the research project "Situational behavior control for interactive, automated guided vehicles" a voice and gesture-based control concept was developed and implemented on an automated forklift truck. Based on an industrial application the economic value of this system is to be reviewed in the context of a material flow simulation.
gesture control, speech control, automated guided vehicles
A factory planning is currently being assessed either at low cost and qualitatively by experts or quantitatively by a simulation model. A review by simulation model is both more costly and time-consuming and a big burden for small and medium enterprises. This article describes the procedure of a research project and the selection of evaluation fields that will in future allow a low-maintenance and at the same time quantitative factory evaluation.
factory planning, quantitative factory evaluation, simulation model
Controlling the time synchronicity of supply processes for assembly requires a quantitative measure. An existing controlling instrument, the supply diagram, already provides an effective way of assessing the supply situation. It incorporates different key figures which allow for an evaluation of a company’s supply process coordination. However, it lacks a key figure for describing the level of time synchronicity. Therefore, a quantitative evaluation of actions to improve the time synchronicity in supply processes is not possible. Based on an existing approach of approximating the completion of full assembly orders, a key figure for describing the level of time synchronicity is developed in this article: the synchronicity factor. As this new key figure is dependent on the average number of components required for one assembly order for the regarded time period, a second measure, the relative synchronicity factor, accounts for this number and can thereby be used to compare different time periods. As the numerical calculation of the synchronicity factors is a complex problem, the possibility of applying a simple hill climbing algorithm to accurately determine the synchronicity factor for a certain supply situation is examined.
Production planning and control, supply chain management, supply diagram, time synchronicity
Within this article a decentrally controlled, intelligent material flow system is presented. The novel product routing is based on a decentralized intelligence and conducts the route planning of the individual materials. The decentralized intelligence permits an expansion or adaption of the production line at any time without significant configuration. In addition, the networked decentralized intelligence allows a parallel flow of material and information, and an identification of the layout of the entire conveyor system. Another core element is the decision-making cognitive conveyor, which is composed of small-scale conveyor modules. In addition to transporting, injecting and ejecting a variety of intralogistics functions can be solved with the cooperation of these conveyor modules. For this cognitive conveyor a drive solution is presented that meets the requirements in terms of functionality and compactness.
Decentralized Intelligence, Material Flow, Cognitive Conveyor, ProductionML, Routing
In this article a small scale, cyber-physical conveyor system using the example of a cognitive conveyor is presented. This cognitive conveyor is modularly assembled of individual conveyor modules that are smaller than the transported units. Furthermore the cognitive conveyor is in the position to handle different intralogistical functions such as transport unit's transporting, rotating, buffering and sequencing. Parallel to the route of the physical transport unit, a data shadow is moved: Hereby all data describing the transport operation are available at any time of transport. Cognitive conveyor's control is decentralized and distributed. Hereinafter both the hardware setup of the conveyor modules and the necessary control algorithms are described. The control algorithms are on the one hand used to move the physical transport unit on the surface of the cognitive conveyor. On the other hand it is utilized to align the data shadow with physical transport unit's information.
cyber-physical conveyor technology, decentralized control, material flow, ProductionML
Flash-reduced forging is a promising alternative for forging complicated high-duty parts. With a new process chain, the ability to reduce the existing flash quota of complex high-duty parts can make the difference in the competition and reduce the costs compared to flashless forging. The European Union is funding a research project which deals with the improvement of the forging sequence of a two-cylinder crankshaft by using flash-reduced forging. To increase the forecast quality of simulations using Finite-Element-Analysis for a future process chain design, the conventional existing process chain is simulated with FORGE3 and compared with industrial forging trials. Furthermore, a variation of simulation parameters has been used to get the significant influence parameters, fitting the results of these forging trials.
Forging, crankshaft, flash reduced, investigation simulation parameters
IPH offers independent testing of conveyor belt idlers. For this purpose we dispose of measurement technology and modern test rigs. We provide the determination of size and weight of idlers (DIN 22112), running resistance (DIN 22112), concentricity deviation (DIN 22112), axial relocatability (DIN 22112), breakaway mass (SAB 1313) and balancing quality (DIN ISO 1940).
conveyor technology, conveyor belt idlers, test rig
The ongoing change from make-to-stock to make-to-order production and the increasing interaction in value creation networks lead to growing challenges for companies regarding delivery date and delivery quantity flexibility. This leads to increased work load scatter in the production systems of companies. This paper presents a simulation-based approach on how the work load scatter can be reduced to a lower level and how this influences logistical characteristic lines.
load scattering, load variation, quantification, batch splitting
Production companies are faced with an increasingly turbulent business environment, which demands very high production volumes and delivery date flexibility. If a decoupling by storage stages is not possible or undesirable from a logistical point of view, load scattering effects the production processes. This expresses itself in the form of heavy load scattering. What kinds of quantification of the load scattering exist and how these have been further developed is subject of the following article.
load scattering, load variation, quantification, production planning and control
The use of 3D printing techniques gives manufacturing companies the opportunity to implement new production processes and to unlock economic potentials. In this article a research project is presented, which aims to analyse the use of build-operate-transfer models with 3D printers. Thereto an evaluation and implementation tool for build-operate-transfer models is being designed, which considers the perceptions of the suppliers and the costumers.
3D printer, build-operate-transfer models, production organization, profitability, production logist
The condition-based maintenance of a marine gearbox poses special challenges because of the inaccessibility to the hull of the ship and harsh environment in the form of higher temperatures, continuous vibrations and salty sea air, which can lead to corrosion. In this article, the integration of a wireless sensor network with a marine gearbox is shown. The integration consists of sensor nodes that record characteristic measurement data, send them actively to a receiving unit and harvest energy from the environment for electrical supply after a one-time installation expenditure. The developed sensor node has a thermoelectric power supply that allows measurement intervals of less than 20 minutes. The recorded vibration data from the gearbox surface are sent via ZigBee wireless technology. By evaluating the envelope spectrum of the measured vibration data, the current rotational speed of the input drive shaft could be identified.
energy harvesting, thermoelectric generator, wireless sensor network, condition monitoring
8D-reports are used to analyze and eliminate errors. Often the quality of 8D-reports is poor and leads to long processing times and problems in sustainable trouble shooting. An automated evaluation system helps to identify quality problems. It prevents companies from sending poor 8D-reports to their customers.
quality management, complaint handling, 8D-report, quality evaluation, evaluation method
An artificial neural network is developed to predict the form filling in forging sequences. This model uses various cross sectional area properties to improve the form filling prediction and to estimate simulation results. The effect of different cross sectional area properties on the prediction quality of the form filling is shown and the best way to predict the form filling is chosen.
FEA, forging, preform optimization
A numerical model using FEA is developed to investigate the generation of thin flash in aluminum forging. Significance and effects of the influencing parameters temperature, forming velocity and width of flash gap on the thin flash generation are shown by statistical analysis carried out with the established model. Experimental trials have been made to verify the model.
FEA, aluminum, forging, flashless forging, thin flash
Despite the high economic potential, only a few companies in Lower Saxony have implemented Industry 4.0 approaches so far. Therefore a new Industry 4.0 Competence Center is introduced in this article. The Center supports companies in Lower Saxony on their way to Industry 4.0 with a wide range of services. As part of a national initiative of the Federal Ministry of Economics the Competence Center’s objective is to significantly increase the implementation of Industry 4.0 solutions within the next three years.
industry 4.0, competence center, digitalization
Increasingly rising electricity prices endanger the competitiveness of the German industry. If fluctuating electricity prices resulting from renewable energy are used, a reduction of production-related energy costs is possible. Therefore the capacity control opens a new field of action. In this paper, a backlog control is introduced, which selects the time of adjusting the capacity in response to energy prices.
time variable electricity prices, fluctuating energy consumptions, manufacturing control, capacity c
This article shows how the known human capabilities for flexibility and adaptation to changing environmental conditions, which are reflected in the cognitive characteristics of people, can be transferred to forklift trucks in intralogistics. As examples for the implementation of Industry 4.0 in intralogistics, technologies are introduced that allow forklift trucks to recognize their surroundings, to communicate information, to conclude and therefore act autonomously, to make decisions, to learn or to plan. These capabilities are realized by an optical positioning system, a camera-based storage and retrieval support system, tire integrated sensors and new interaction concepts for forklift trucks in the form of speech and gesture.
forklift truck, gesture control, speech control, 3D-camera, optical positioning system
Many companies can or must reduce energy consumption in their production. The Institut für Integrierte Produktion Hannover (IPH) has developed procedures and a formula with which companies can improve the energy balance. At the same time the quality of products can be increased by this approach.
process management software, quality costs, reliability engineering
The most common method of bulk forming processes is closed die forging with flash. In these processes a surplus of material is used to ensure a complete filling of the cavity of the forging die. The surplus material is driven out of the die through the flash land, thus the design of the flash land has a major influence on the filling of the die. All dimensions of the flash land are typically fixed during the manufacturing process of the die and can not be changed within the forging process. By use of a moveable flash gap that can be actively changed during the forging process the material flow can be altered. This permits to improve the filling of the cavity. In this paper a moveable flash gap for a hot forging process is described and the influence of such a system on the filling of the die cavity is determined. This is done by a comparison to a conventional forging process with a fixed flash land. Furthermore, the results of experimental trials are compared to results of corresponding FEA simulations. Additionally, the influence of the initial billet temperature is investigated. Experimental trials showed that the moveable flash gap has a distinct influence on the material flow. The higher the flash ratio, the bigger is the influence of the moveable flash gap. The moveable flash gap is designed as a flash brake of a height of 2 mm. Its usage lead to differences in height of the parts up to 4.5 mm, which correspond to 16.6% of the parts height, compared to parts forged with a fixed flash land. If the forging temperature is decreased from 1200 °C to 1000 °C, the influence of the moveable flash gap is reduced. The average differences in height are about 0.5 mm (about 3%).
forging, die design, material flow, FEA, flash land, flash gap
