Publications

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

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

During the assembly of large-scale products, disruptions often occur. To reduce these disruptions, a straightforward approach to their systematic processing is needed. This should automatically identify similar disruptions and independently suggest sensible corrective measures. For this, the disruptions are first collected and characterized and a model for practical information flows is created. Then, in a multi-stage similarity search, similar disruptions are identified, and suitable corrective measures are derived.

Disruption management, single and small batch assembly, large scale products, similarity search

The assembly of XXL-products is often organized according to the job-site principle. With this principle, the assembly objects are arranged stationary and the necessary resources and materials are brought there. If several job-site assemblies are arranged simultaneously at the assembly area, an area-allocation-planning is necessary to prevent the available area from becoming a bottleneck. The area allocation planning can follow different design variants, which differ regarding the degree of freedom in the area arrangement, their organizational framework conditions as well as the tolerance against external influences. The possible general design variants and how they differ in terms of performance, planning reliability and resulting costs for
different framework conditions has not been researched yet.

This study shows that companies can optimally align their area-allocation-planning regarding the performance indicators productivity, planning reliability and expenditure by the implementation of an appropriate design variant. For this purpose, the special characteristics of job-site organized assemblies are analyzed, relevant influencing factors identified and the possible variants for the design of the area-allocation-planning are derived. In order to evaluate and compare them with each other, a simulation model is applied which maps the area allocation planning for all design variants depending on the influencing factors. The results of a simulation study carried out with this model confirm the different characteristics of the design variants and their individual suitability for specific conditions.

assembly, job-site-principle, area allocation planning, xxl-products

Manufacturing companies are trying to meet individual customer requirements by increasing the number of product variants. The customization of products often takes place in the assembly. The assembly is also the last step in the industrial value-added process and is often affected by disruptions.

Disruptions in the assembly processes have a negative impact on the manufacturing company's logistical objectives and therefore their competitiveness. Due to the high complexity of assembly, a disturbance often leads to further disturbances. In addition, manufacturing companies are forced to reduce time, capacity and inventory reserves due to global competitive pressure and therefore can react less flexibly to disruptions.

For this reason, an approach to the production planning and control of the assembly is developed which describes the interdependencies of actions for dealing with disruptions to the logistical objectives.

production planning and control, assembly, possibility of disturbance, sequencing, simulation

The dismantling of wind turbines is gaining in importance. The reasons for this are the expiry of feed-in tariffs for a large part of the German plant stock as well as the technical and economic end-of-life of wind farms. Operators and dismantling companies are faced with the challenge of organizing the dismantling process efficiently. There is a conflict of objectives between the positioning of the complex and expensive dismantling at the site of operation and the expensive transport of components of a wind turbine that are not further dismantled to a dismantling factory where a more cost-effective dismantling is possible. In the research work, the most important factors influencing disassembly are summarized in an impact model and transferred into a mathematical model. The mathematical model is based on a site planning and allocation problem for wind turbine disassembly. By applying the model to a framework scenario and conducting a parameter study, recommended actions for the individual components in the dismantling of a wind turbine are developed. In addition to the allocation of dismantling tasks to dismantling sites, these also included recommendations for action with regard to dismantling planning and documentation.

Wind energy, dismantling, site planning and allocation problem, dismantling networks

3D printing of large mechanical engineering components with a unique character, such as ship gearbox housings, has great development potential as so-called additive manufacturing. As an alternative to casting with complex mold construction, additive manufacturing of such large products offers significantly greater design freedom. To this end, a consortium of research institutes and companies from Hanover, Langenhagen and Hamelin is jointly developing an XXL 3D printer with an installation space of 4.5 m * 3 m * 1.4 m. The printer will be used for the production of large parts.

Additive Manufacturing, 3D printing, XXL-products, Production of unique pieces, quality control

Within the project "CoMoGear - Condition Monitoring of Marine Gearboxes based on Wireless, Energy-Autonomous Sensor Nodes", an energy-autonomous, wireless sensor network was developed for condition diagnosis of highly stressed rotating components in marine gearboxes was developed. This allows intelligent, condition-based monitoring and maintenance, paving the way for unmanned shipping.

sensor nodes, condition monitoring, marine gearbox, energy harvesting

Within the CoMoGear project, an energy self-sufficient wireless sensor network for the condition monitoring of highly stressed rotating components in marine gearboxes was developed. This sensor network consists of several sensor nodes and energy harvesters.

sensor nodes, condition monitoring, marine gearbox, energy harvesting

More and more players in the German wind energy sector are concerned with the question of how to deal with the aging German wind fleet, as around 5,200 turbines will simultaneously reach the end of the feed-in tariff funding period of the Renewable Energy Sources Act (EEG) for the first time at the end of 2020. Around 8,000 wind turbines will follow by the end of 2025, as shown in Figure 1. Operators of affected wind turbines will then have the choice between (I) continuing to operate the old turbine within the framework of direct marketing on the European Power Exchange, (II) repowering the old turbine by a new and more efficient wind turbine at plant-specific feed-in premium levels tendered in the German renewable energy auctions or (III) decommissioning the respective plant finally.

However, the question of choosing the right option arises not only for the operators themselves, but also for various other players in the wind energy sector:

Project developers, turbine manufacturers, and investors are interested in evaluations of plant-specific repowering potentials in the existing wind turbine fleet in order to provide operators with targeted support in implementing new projects; dismantling contractors and disposal companies particularly search for derivatives of plant-specific dismantling potentials and the associated disposal and recycling flows in order to enable optimal handling of the comprehensive dismantling processes; and regional as well as supra-regional public and political institutions are interested in estimates of changes to the installed wind energy capacity in order to enable optimal control of future capacity expansion under consideration of societal, economic and political aspects.

dismantling, wind turbine

In this paper, the validation of an inductive sensor for an energy self-sufficient sensor for condition monitoring of wet-running steel disc clutches in marine gearboxes is presented. For a reliable operation of these a permanent monitoring of their state is advisable. As part of condition-based maintenance, more and more sensors are being installed in machines. Reliability becomes even more important when people are endangered by possible failure of the machines. In shipping, it is essential that, for example, the powertrain and thus the transmission are in perfect condition. In case of long distance traveling, wear or even damage of important components has to be known so that maintenance can be carried out proactively. To address this need an energy self-sufficient and wireless sensor network is developed. Miniaturized sensor nodes monitor torque, rotational speeds, temperatures as well as the wear condition of the torque transmitting components. The energy needed to operate these sensors is obtained from the surrounding environment. Thus, the system operates wirelessly and without an external energy supply, whereby the installation and maintenance costs decrease significantly. In addition to the concept of sensor integration in the transmission, the energy harvesting concept is also described in more detail. Finally, measurements are taken in a gear-like environment and the behavior of a magnetoinductive sensor in a not constantly supplied situation has been examined.

ship, gearbox, wear, sensor, torque

At the end of 2020, around 6,000 wind turbines will simultaneously fall out of the 20-year subsidy under the Renewable Energy Sources Act (EEG) for the first time. Around 8,000 further wind turbines will follow by the end of 2025. Operators of affected wind turbines will then have the choice between continuing to operate the old turbine at the significantly lower spot market prices of the European Power Exchange (EPEX), operating a new and more efficient wind turbine at the site of the old turbine (repowering) at auctioned conditions or finally decommissioning it. Quo vadis 20 years old Wind trubines? Scientists from the Institut für Integrierte Produktion Hannover (IPH) have therefore been working on the "DemoNetXXL" project, funded by the German Research Foundation (DFG), in cooperation with the Institute for Information Systems at Leibniz University Hanover on the selection and design of optimal post-utilisation strategies for wind power plants.

wind turbines, plants repowering, post-use strategies, dismantling

This paper describes the development and prototypical implementation of an energy self-sufficient sensor for condition monitoring of wet-running steel disc clutches in marine gearboxes. For the precise control of an automated system and the monitoring of its performance, the knowledge about the possible wear is an essential prerequisite. In addition, the storage of sensor data over the life of the system offers the possibility of long-term condition monitoring. The combination with various other technological components creates a solution that enables cost-effective condition monitoring of marine gearboxes. Compared to existing systems, for example, the costs for installation and maintenance are significantly reduced. Both the methodology from the morphological box to the fine concept as well as the first measurements of the sensors are presented.

automated system, condition monitoring, metrology, clutch, gearbox

In average, more than 1,275 wind turbines were installed annually since 1997 in Germany and more than 27,000 wind turbines are in operation today. The technical and economic life time of wind turbines is around 20 to 25 years. Consequently, dismantling of aging wind turbines will increase significantly in upcoming years due to repowering or decommissioning of wind farms and lead to millions of costs for operators. An option to supersede the costly and time-consuming dismantling of wind turbines entirely on-site is to establish a dismantling network in which partly dismantled wind turbines are transported to specialized dismantling sites for further handling. This network requires an optimization model to determine optimal locations and an appropriate distribution of disassembly steps to dismantling sites. The challenge is to consider the networks dependency on the trade-off between transportation and dismantling costs which, in turn, depends on the selection of dismantling depths and sites. Building on the Koopmans-Beckmann problem, we present a mathematical optimization model to address the described location planning and allocation problem. To permit a proof-of-concept, we apply our model to a case-study of an exemplary wind farm in Northern Germany. Our results show that the model can assist dismantling companies to arrange efficient dismantling networks for wind turbines and to benefit from emerging economic advantages.

dismantling, wind turbine, optimization model

Rotary energy harvesters offer the possibility of generating energy in the center of rotation or outside of the center of rotation. There are both concepts with reference to the outer housing as well as different concepts without a fixed reference. In addition, Energy Harvester solutions are available that provide energy to the housing and generate energy through the rotation of the shaft. The selection of a concept must be made individually for each application and depends on various influencing factors. Decisive in particular are the installation space, the energy requirement of the sensor node and the speed.

energy supply for microsystems, energy harvesting, rotary energy harvester, power management

The introduction of continuous condition monitoring of machinery and equipment is associated with obstacles, especially for retrofits in the maritime sector. Sensor networks in conjunction with wireless, energy-autonomous sensor nodes completely avoid the cabling effort for energy supply and data transmission, so that the sensors for measuring value acquisition can be integrated with a single installation effort. Energy Harvesting systems allow the sensor nodes to be supplied with energy from the immediate environment.
The aim of the present work is therefore to develop a model that enables the energetic design of wireless, energy self-sufficient sensor nodes for condition monitoring of machines and plants.

wireless sensor network, energy harvesting, energy-independent sensors, condition monitoring

Marine gearboxes ensure the reliability of the entire ship. Therefore a timely maintenance is crucial. To decrease maintenance costs and increase security, IPH develops a wireless and energy-autonomous measurement system to monitor marine gearboxes from afar.

gearbox, ship, condition monitoring, maintenance

Wind turbines can withstand more load changes than bridges or helicopters - but at some point they, too, have had their day. Operators of wind turbines should therefore consider their options for continued operation, repowering or complete dismantling before the end of the approved operating period. Together with practical partners, the Institut für Integrierte Produktion Hannover (IPH) gGmbH is researching how dismantling can be carried out quickly, cost-effectively and in an environmentally friendly manner. The project "Development of an impact model for the efficient design of dismantling networks for XXL products" is funded by the German Research Foundation (DFG).

dismantling, wind turbine

Whether aircraft, ships or construction machines: The assembly of so-called XXL products requires a lot of space. Researchers at IPH are currently developing a method which enables companies to find an ideal layout. By this means, they can save space and increase their productivity.

XXL products, area arrangement

Assembling large-scale products involves frequent process interruptions why in order to reduce the impact of interruptions, a short-term response is necessary to reduce delivery delays and idle times of resources. An approach to challenge this represents the flexibility of a production system. Regarding the environment of large-scale product assembly, it has to be shown which potentials of flexibility are able to be used in a short-term manner.

assembly, production management, disruption management

This article describes the necessity of considering temporal dynamics in the arrangement of assembly areas for large-scale products. This is justified by the fact that the available area represents a bottleneck and thus using of an intelligent arrangement of the areas can lead to an increased utilization of the factory.

XXL-products, assembly area arrangement

Thousands of wind turbines need to be dismantled and replaced in the next years. The owners of the wind parks have to pay millions to handle this. How you can dismantle quickly, at a low price and ecologically friendly, is part of a research project of the Institut für Integrierte Produktion Hannover (IPH). The huge dismantling wave will start in the next years.

dismantling networks, wind turbines

Disassembling of large-scale products (e. g. wind energy plants, crane and conveyor systems which are known as XXL-Products) becomes increasingly important, as the operating time is limited. The challenge is to optimize the positioning of the complex and expensive disassembling on the operation site on the one hand and the costly transportation of modules to the disassembling factories. For this reason the location and allocation problem will be pictured in a mathematical model within the research project “DemoNet”. This model supports companies to create a XXL-disassembly-network. The research hypothesis assumes: a disassembly under ecological, economical and logistical aspects constitutes the optimum. The extension of a location planning tool forms the basis of the mathematical optimization model for the disassembly of XXL-Products. For solving the problem a genetic algorithms will be used. The result helps companies to arrange disassembling networks for XXL-Products efficiently.

dismantling planing, dismantling networks, impact model

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

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

The integration of a wireless sensor network at a marine gearbox provides the opportunity to have a one-time expense of installation. The wireless sensor network consists of sensor nodes, which record characteristic measurement data, send them actively to a receiving unit and harvest energy from the environment for electrical supply. By evaluating the envelope spectrum of the measured vibration data, an artificially generated bearing damage could be identified.

sensor nodes, energy harvesting, condition monitoring, marine gearbox

Manufacturing companies of xxl-products are increasingly forced to distinguish themselves from their competitors by the production costs. However, many manufacturers don’t have the capabilities to identify and evaluate approaches to optimize their production. Reasons for this drawback are limited capacities or financial restrictions. Therefore this paper introduces a new approach to the identification and selection of optimization approaches for manufacturers of xxl-products.

flow-production, xxl-goods, manufacturing principles, prefabrication

The assembly of large-scale products is usually organized in the construction-site principle. For each assembled product, the area requirement increases with assembly time. So for each product a defined area is reserved, that corresponds to the maximum expansion of the product. As the existing area is limited, the single products are competing for it. This results in an increased area requirement and a poor use of area. Therefore time-variable and competing area requirements should be considered in the facility layout planning.

layout problem, time dynamics, competing areas

In this paper an approach to establish a flow-production in the production of xxl-goods is presented. The developed approach is based on three sequentially steps and takes the specific conditions and characteristics of the xxl-production (e.g. high customization, highly scattering process times) into account. With the developed approach a safe forecast on the economic impact of a manufacturing reorganization is made, so that investments in failing reorganization attempts can be avoided.

xxl-production, flow production, site production, reorganization

Compared to conventional demolition processes (e.g. living houses) the demolition of industrial plants, such as nuclear power plants, is more challenging for the management of logistics processes (e.g. due to spatial and legal restrictions). Therefore the demolition of a nuclear power plant can take up to ten years and incur costs by 4 billion euros. Controlling the logistics processes can reduce these costs and the required time significantly.

dismantling management, demolition

Assembling large-scale products involves frequent process interruptions induced by e.g. delayed material deliveries or missing availability of resources. Our approach for identifying alternative assembly sequences by analyzing the product structure and process dependencies allows for continuing with the assembly process in case of interruptions and therefore increases the process efficiency.

large-scale product, adaptive assembly, alternative assembly process

This article presents a solution for the thermoelectric power supply of wireless sensor nodes for condition monitoring of marine gearboxes. Among the different ambient energy sources in marine gearboxes, frictional heat has been identified to be appropriate to thermally power a thermoelectric generator (TEG). The such generated electricity may power wireless sensor nodes for detecting temperature, vibration, torque and rotational speed. Requirements for a corresponding energy supply are formulated, constructive solutions are presented and thermal simulations and practical experiments are reviewed. The results are evaluated and a solution is selected for further implementation, which provides for an actively cooled TEG in the area of the ship gearbox’s heat exchanger. This can provide continuous electrical power of up to 14 mW, thus supplying the planned sensor nodes. The disadvantage of this solution is that a comparatively extensive mechanical modification, for example, to the oil and cooling water pipelines is required.

energy harvesting, thermoelectric generator, wireless sensor nodes, thermal simulation, condition mo

As a highly-loaded element between the diesel engine and propeller installation, the marine gear has a special significance with regard to the reliability of the entire ship propulsion. Together with project partners from industry and research a condition monitoring system has been developed by the IPH, to prevent failures. The peculiarity of the system is the wireless and self-powered operation.

condition monitoring, wireless sensor nodes, microcontrollers

The lecture introduced IPH – Institut für Integrierte Produktion Hannover gGmbH with its three fields of activity: forming technology, logistics and automation technology. Furthermore, research and consulting projects were discussed. In addition, Industrie 4.0 was presented as a major focus of current research.

industrie 4.0, automation technology, logistics

In multi-site assembly, problems such as defective tools require assembly control to react promptly in order to avoid negative consequences, such as deferred deliveries or additional costs. A method is presented which uses statistical online simulation based on structured assembly plans to quickly identify and evaluate possible options for dealing with a problem. Furthermore, the structure and procedure of a purpose-built simulation system is shown in this article.

assembly control, simulation, production planning and control, failure management

While definitions already exist for smaller scale device structures e. g. nanotechnology, the conceptual distinction between standard large products and large scale or XXL products is currently insufficient. This study presents a basic definition of large scale products. At first hypotheses are being derived and examined at an empirical study of three sample products threaded nuts, screw presses and passenger aircrafts. It will be shown that the transition from conventional products to XXL large scale products is characterized by a disproportionate increase in the ratio of product costs to the augmentation of a characteristic product’s feature. Based on the results a definition for the characterization of large scale products is established referring to the technical, organizational and economical restraints and to the available processes and tools.

xxl-product, large-scale, xxl, definition

The range of structure sizes for industrial products produced today is increasingly expanding. This trend is evident in both small-scale (e.g. semiconductor applications) and large-scale (e.g. wind turbine rotors) products. While definitions already exist for smaller scale device structures, the conceptual distinction between conventional large products and large scale products is currently insufficient. In this study, we present a potential basis for the definition of large scale products. To achieve this, we derive hypotheses and examine these in the context of an empirical study using the examples of several sample products. It is shown that the transition from conventional products to large scale products is characterized by a disproportionate increase in product costs due to the augmentation of a characteristic product feature. Eventually we derive a proposed definition which characterizes large scale products in the field of production engineering.

xxl-product, large-scale, xxl, definition

Products have historically been subject to continuous development. On the one hand, these are to fix known issues and bugs compared to the original product. On the other hand, companies are forced by globalization to optimize their products globally in order to stay competitive in the market. Such development often involves not only a function of growth, but also needs a development of the geometric dimensions. For Example, the VW Golf has been added more and more safety and comfort features with each generation. In this way, the length of the VW Golf with every model change has increased by an average of 9cm.

xxl products, large-scale products, xxl definition

By increasing the height of wind turbine generators the usable wind energy increases exponentially. However, tower weight increases accordingly. Current tower designs limit the tower height due to the explained correlation. The application of lightweight design concepts can lead to a significant weight reduction at comparable tower stiffness. As part of a research project, lightweight design concepts have been developed. These design concepts allow a mass reduction for onshore wind turbine towers up to 20 %. In this paper, the development and results regarding these lightweight concepts are presented.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

The utilization of lightweight engineering methods for tower construction of wind turbine generators enables a weight reduction at constant stiffness. Thus an increase of the tower’s height can be achieved, while keeping its weight. Within a research project at IPH several lightweight engineering solutions from bionical, aviation and aerospace applications have been investigated. According to the developed guidelines a lightweight concept based on trapezoidal sheets can reduce the mass of a 3 MW generator of 90 m height by 20 %. In this article certain details of the construction are being presented.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

Schedule variances in the cycle of field assembly often cause high unplanned costs. This is particularly true for capital-intensive, large-scale products. Currently no model exists which supports cost determination already during planning, implementation or after assembly. Thus, comprehensive logistics controlling is not possible which prevents high schedule adherence and low logistics costs even on the occurrence of disruptions. In this paper, a research project is presented, which has the goal of developing a method by which a deadline- and cost controlling of the material availability for the assembly of wind turbines can be secured.

material provisioning, site assembly, cost controlling, schedule deviation, early warning system, fo

The production with assembly lines is highly efficient, but can it also be used for XXL products? Typical XXL products such as ships, aircrafts and wind turbines are not only larger and heavier than conventional products, but also much more complex. They are produced in a higher variety than conventional products, the degree of customer influence is greater – thus the processing contents vary during production. In addition, XXL products consist of a huge number of components and their value also is higher than that of conventional products. The manufacturing of XXL products therefore still largely follows the principle of the construction site.

xxl products, assembly, site production

In this paper, a novel, widely usable gripper system for craneless and weather-independent assembly of rotor blades for offshore wind turbines is presented. This gripper system was developed in the context of the research project "XXL Assembly aids" of the IPH - Institute of Integrated Production Hannover gGmbH.

assembly aid, wind energy plan, xxl-products

Growing XXL products reach dimensions that are no longer manageable by humans without innovative technological support. Therefore (semi-)automated assembly aids for the final assembly of large components are needed. The assembly of XXL-products is similar to the construction of prototypes. The aim is to avoid redundant new developments and designs of installation aids and to make them available across processes. In addition to presenting a method to systematize and select the right installation aid, the development of a gripper system for craneless and thus weather-independent assembly of rotor blades for offshore wind turbines is shown in this paper.

assembly aid, wind energy plan, xxl-products

A xxl-product is defined as product, whose production costs increase disproportionately in relation to further growth of a characteristic product feature. Existing models of supply chain design are not designed for xxl-products. For this reason a method was developed to create a supply chain for a xxl-product. The supply chain design works in due consideration of the most relevant xxl-product specific features. The created supply chain can be evaluated for their logistical quality. Therefore a comparison between different supply chain variants is possible.

xxl-product, supply chain design, logistical objectives

The assembly of complex, large-scale products is often characterized by poor date availability, limited process standardization, frequent product modifications and flexible usage of resources, which often leads to interruptions in the assembling process. Therefore, in a research project between the IPH Hannover and the WZL of RWTH Aachen University, a methodology for assembly processes is developed which allows the identification and evaluation of process alternatives in case of interruptions. For the evaluation of those process alternatives logistical objectives are used.

xxl-product, adaptive assembly scheduling, interruption assembly process, logistical objectives

Data analysis on a microcontroller in the immediate vicinity of the measuring point creates an intelligent sensor node that enables a condition prognosis of gearbox components. The IPH compares different approaches of analysis regarding computing time and energy consumption in order to minimize the effort of wireless data transmission.

condition monitoring, wireless sensor nodes, microcontroller

The lecture introduced IPH – Institut für Integrierte Produktion Hannover gGmbH with its three fields of activity: forming technology, logistics and automation technology. Furthermore, research and consulting projects were discussed. In addition, the challenges regarding the production of large-scale products were presented as a major focus of current research.

xxl products, large-scale products, production technology, logistics, automation technology

Economic growth in Germany and Europe secures jobs and prosperity. However, the impacts on our environment are often negative. Because more goods are produced and the consumption increases, traffic and thus the greenhouse gas emissions rise. In order to keep these emissions as low as possible, the stated goal is to shift transport from road to rail. Thats why many terminal stations are preparing for rising turnover figures. However, the problem of maximizing throughput capacities is unsolved. To answer this question, the IPH has developed an innovative, event-discrete model used in a material flow simulation based on the software Plant Simulation.

connection station, simulation model, material flow simulation

A breakdown of a wind turbine entails high costs. The more reliable the prognosis of the condition of every single component is carried out, the better the maintenance can be planned. For example the maintenance could run in a time with low wind yield. Furthermore, impending breakdowns can be detected and avoided. Within the project “SteigProg” data-mining algorithms were analyzed for their ability to condition prognosis in wind turbines. An improved condition prognosis contributes a more efficient operation of wind turbines. Measurable savings result by minimizing downtimes, improved planning and shortening of maintenance operations.

condition prognosis, wind turbines

The production of large-scaled products is often associated not only with great challenges, but also with enormous costs. The way how the product is designed offers the greatest potential for cost reduction. At the IPH, engineers are currently developing a new modular design for XXL products.

xxl products, modular design

Planning in a multi-site, non-mass production environment is a special challenge because of several sources of uncertainty. Unlike in mass production facilities, in our setting the current state is not easily and exactly known when the case of re-planning occurs. The planning procedure has to contribute to that fact, as well as to further uncertainties concerning the effects of a plan when evaluating the plan. Thus in this work, we apply online simulation as means for re-planning multi-site production in the case of resource failure. This work is a first step where two alternatives are considered when a resource fails: either wait for repair of the resource, or transport another instance of this resource from another site, if there is more than one available. Our study shows that the planning using online simulation is superior to a static strategy such as 'always wait for repair' or 'always import resource' in case of resource failure.

assembly control, simulation, production planning and control, failure management

The usable wind energy increases exponentially by increasing the height of wind turbine generators. The material requirements and the tower weight increases disproportionately high by growing tower height. In current designs, the height of towers is limited. The application of lightweight design concepts in the production of wind turbine tower sections can lead to a reduction in the weight with the same tower stiffness. Therefore lightweight designs have great potential to increase wind turbine efficiency. In this paper, the results of the research for lightweight concepts and their implementation on towers and a guiding systematic approach are presented. As part of the research, design concepts have been developed. These design concepts allow the mass reduction, with constant stiffness, for the wind turbine towers on land (onshore). Several investigation loops of these lightweight designs were run. Different concepts of bionics, aviation, aerospace and automotive have been investigated for their suitability in wind turbine towers. A suitable concept was identified based on trapezoidal sheets. Using these sheets, the weight of towers can be reduced by 20 %.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

At the Institut für Integrierte Produktion Hannover gGmbH (IPH) a method is currently being developed, that supports the controlling of logistical targets and associated logistics costs in the supply chain for the assembly of wind energy plants. The considered supply chain comprises all steps from the production of the individual components up to the handover to the customer. The method enables continuous prediction whether date variances have a critical monetary and scheduling impact on the project success.

material provisioning, site assembly, cost controlling, schedule deviation, early warning system, fo

In multi-site assembly, problems such as defective tools often cause delays. In order to avoid deferred deliveries and increased costs, assembly control is required to promptly determine a new assembly plan. A research project aims to develop a software support system which assists assembly control in the replanning process by applying online simulation to quickly identify possible plan alterations and evaluate their expected impact on logistical key figures.

assembly control, simulation, production planning and control, failure management

Manufacturing companies of xxl products are increasingly forced to distinguish themselves from their competitors by the production costs. Commonly used manufacturing principles are designed for a customized production with high product variety. However, with regard to the production costs these manufacturing principles are insufficient. The transfer of alternative manufacturing principles to the xxl production offers a promising approach to increase the productivity.

flow-production, xxl goods, reorganization, manufacturing principles, prefabrication

The product design already determines 70% of the future product costs. Therefore, the structural design offers a promising approach for reducing the lifecycle costs of an airplane. An essential design parameter is the decision between a monolithic or modular construction. The current design of aircraft wings can be described as largely monolithic; the basic structure consists of a small number of undivided components. For example the top cover of the Airbus A350 wing consists of a single component with a length of 32m. For the production of these large scaled components production machines, e.g. autoclaves, with very huge dimensions are needed. However other aircraft parts such as the fuselage are not one-piece components. The fuselage is composed of several fuselage modules, which are pre-equipped and then riveted together. In this paper, a small-scaled modular design for airplane wings is presented and the technical feasibility is discussed. Moreover, we identified modularization factors which significantly influence the decision between a monolithic or modular construction.

structural design, large scaled products, modular design

In general, XXL-Products consist of many different parts which are often individually produced using various manufacturing technologies. Companies collaborate in production networks while focusing on their core competencies. In order to realize an evaluation and improvement of the network’s logistical maturity level and thus the logistical efficiency, a maturity-level-based development guideline is needed.

supply chain management, supplier evaluation, production networks, logistical performance, maturity

The lecture introduced IPH – Institut für Integrierte Produktion Hannover gGmbH with its three fields of activity: forming technology, logistics and automation technology. Furthermore, research and consulting projects were discussed. In addition, the challenges regarding the production of large-scale products were presented as a major focus of current research.

research and development, xxl products, large-scale products, production technology, logistics, auto

In order to achieve higher energy yields of wind turbine generator, the most expedient approach is to enlarge the tower height. By increasing the height the usable wind energy increases exponentially, but also does the tower weight. Therefore in a research study several constructional designs for lightweight tower design have been investigated. The design considered several design solutions which proved successfully in bionic, aerospace and automotive applications. FEA simulations were used to compare different structures and to estimate their feasibility. The best-fit identified constructional design is based on trapezoidal sheet. The developed design enables a weight reduction up to 20 % in comparison to standard towers.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

A smart option to increase the energy yield of wind turbine generators is to increase its height. There is an exponential increase of the usable wind energy at enlarging the tower’s height, but also an exponential increase of the tower’s weight. The application of lightweight design concepts in the production of wind turbine tower sections may lead to weight reduction while keeping the tower’s stiffness at an equal level. Here the results of a study for lightweight concepts and their implementation on towers and a guiding systematic approach are being presented. The investigated design solutions proved successfully in bionic, aerospace and automotive applications. FEA simulations were used to compare the different structures and to estimate their feasibility. The investigation’s main result is a lightweight structure which provides weight reductions up to 20 %, by using lower wall thicknesses.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

This paper discusses the different characteristics used to describe XXL-Products and, furthermore represents fundamental aspects concerning the construction (eg. principles, methods) of production systems. A survey of experts at XXL-Producers is used to identify the most commonly used production systems. The article demonstrates the survey results and finally concludes with an outlook on further actions.

lean-production-methods, production system, xxl-products

To meet the growing demand for energy, further developments are necessary in the field of renewable energies. In two research projects, engineers of IPH - Institut für Integrierte Produktion Hannover have investigated how to increase the efficiency of wind turbines.

xxl products, large-scale products, wind turbines, data mining

In the past, scientific analysis of development and production of large-scale products has not been conducted very often. In the joint project „Innovations for the production of large-scale products“, sponsered by two German ministries in the state of lower saxony, IPH – Institut für Integrierte Produktion Hannover gemeinnützige GmbH will make a contribution to reply scientific questions in consideration of development, production and recycling of large-scale products.

xxl-products, development, manufacturing, recycling

Enlarging the height of wind turbine generators leads to exponential increase of the usable wind energy. However the construction’s weight increases equally. Therefore a systematic approach to design lightweight towers for onshore wind turbine generators has been developed in a research project. Different concepts of bionic, aerospace and automotive origin have been used to create lightweight structures for the towers. These lightweight towers have been analyzed by FEA simulations e. g. regarding their fatigue stress. The investigation’s result is a lightweight structure which enables to build wind turbine generator towers of lower wall thickness. Thus a weight reduction up to 20 % can be achieved in comparison to standard towers.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

This paper discusses the different characteristics used to describe XXL-products and, furthermore, presents fundamental aspects concerning the construction (e.g. principles, methods) of production systems. A survey of experts at XXL-producers is used to identify the most commonly implemented Lean-Production-Methods of production systems. The article presents the survey results and finally concludes with an outlook on further steps.

customizing, erp, potential savings, enterprise resource planning, individual adjustment, cost-benef

Large-scale products (XXL-products), such as bearing rings for wind turbines, pose special challenges to the production technology. For example, the continuous growth of product dimensions puts challenges on forming technologies as they reach their technical limits. Scaling effects, that occur when scaling up, can include physical limits for a further upscaling. These effects have only been studied for small scale production processes so far. The consideration of such effects in the large scale production offers the opportunity to exploit the potential of metal forming processes and improve the calculation forecasts.

xxl-products, forging, flowproperties, scaling factor, scaling effect, ring compression test

Next generation wind turbines are to be built higher and higher. As a result of the stronger and more regular wind in greater altitudes, more energy gain can be achieved by rising hub heights of wind turbines. However, the risk of tower failure rises with tower height and mass.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio