While design and management of production systems based on digital models brings benefits, the communication of models comes with challenges since models typically reside in a distributed heterogeneous IT environment using different syntax and semantics. Coping with heterogeneity requires an appropriate integration strategy and methodology. One main paradigm to integrate information and consequently IT-systems is to deploy standardized information models. In particular, ISO 10303 STEP has been endorsed as a suitable standard to exchange a wide variety of product manufacturing data. The representation and integration of product, process and production resources information using different STEP application protocols are well covered and extensively investigated by many researchers. However, the information representation and integration of logical relations of material flow such as product routing, and its integration with factory layout information has been less subject of research focuses. Hence, this thesis first contributes to identifying, describing and clarifying information requirements for an integrated representation of material flow logic and plant layout using the STEP standard. One the other hand, service-oriented IT-tool integration solutions are increasingly deployed for the data and tool interoperability, especially with the evolution of Open Services for Lifecycle Collaboration (OSLC) whose focus is on the linking of data from heterogeneous software tools. OSLC focuses on the integration of the most common concepts across domains. Assuming a loosely coupled distributed architecture of IT-tools and services, OSLC adopts the Linked Data (LD) approach to ensure data consistency across the data sources. Thus the thesis studies the use of OSLC for tool integration and has found that it cannot be practiced independently for all types of integration in the production engineering domain. Therefore, in practice, there should be a combination of the standardized information and linked data approaches to facilitate the integration process. Thus, this thesis investigates the integration applicability of linked data and OSLC, the principles behind them, and criteria to identify where to use which approach. In addition, the thesis explores the synergy between the standardized information and linked data approaches and consequently suggests an approach based on a combination of these. Further, different computer applications in industrial cases were implemented to verify the suggested approaches. Finally the thesis is concluded with a discussion and suggestions for future work. / <p>QC 20170503</p>

The low density and high specific strength of magnesium alloys have created a great deal of interest in the use of these alloys in the automotive and aerospace industries and in portable electronics. All of these industries deal with applications in which weight is extremely important. However, an obstacle to overcome when using magnesium alloys in engineering applications are their unsatisfactory corrosion properties. This thesis is devoted to the atmospheric corrosion of the two magnesium alloys AZ91D and AM50, in particular the ways the microstructure and exposure parameters of these alloys influence their corrosion behaviour. The work includes both laboratory and field studies. The results obtained show that the microstructure is of vital importance for the corrosion behaviour under atmospheric conditions. The microstructure of magnesium-aluminium alloys contains different intermetallic phases, e.g. Al8Mn5 and β-Mg17Al12. The local nobility of these intermetallic phases was measured on a submicron level in an atmospheric environment. It was shown that particles of the Al-Mn type exhibit the highest Volta potential among the microstructure constituents of the AZ91D magnesium alloy. Further, it was shown that the Volta potential was highly dependent on the aluminium content of the magnesiumaluminium phases in the surface layer. When thin electrolyte layers are present, CO2 diffuses readily to the surface forming magnesium carbonate, hydromagnesite. The CO2 lowers the pH in areas on the surface that are alkaline due to the cathodic reaction. This stabilises the aluminium-containing surface film, the result being increased corrosion protection of phases rich in aluminium. Both in the laboratory and under field conditions the corrosion attack was initiated in large α-phase grains, which is explained by the lower aluminium content in these grains. The thin electrolyte film, which is formed under atmospheric conditions, decreases the possibility of galvanic coupling of alloy constituents located at larger distances from each other. Thus the cathodic process is in most cases located in the eutectic α-/β phase close to the α-phases, instead of in intermetallic Al-Mn particles, even though the driving force for the initiation of the corrosion attack in Al-Mn particles should be high, due to their high nobility. / <p>QC 20100802</p>

Discrete Event Simulation (DES) has been a powerful tool for modeling and optimization of production lines for many years. Developing detailed models may be very time consuming and might also be computationally costly to execute, especially if optimization techniques are to be applied. Aggregation techniques, simplifying a detailed system into fewer objects, can be an effective method to reduce the required computational resources as well as a way to shorten the development time. An aggregated model can be used to identify the main constraints in a system, dimensioning inter-line buffers, and focus development activities on the critical issues from a system performance perspective. An aggregated model of a real-world plant wide production system has already been developed in the discrete event simulation software FACTS Analyzer. Due to the limitations of FACTS Analyzer this model was instead rebuilt using the discrete event simulation software Plant Simulation which, while less user friendly, has much more configuration options. This model is then validated against the FACTS Analyzer model to ensure accurate results that can be implemented on a real life system. In addition some typical optimization experiments are carried out on the Plant Simulation model and the results analyzed. The first of these optimizations alters the buffer sizes to find the minimum amount of buffer capacity needed to get the minimum lead time while maintaining the highest possible throughput. The second optimization uses the same parameters but also adds alteration of the batch size. Both of these optimizations shows that it is possible to get better results with lower settings on both the buffer capacity and batch size then the default value. At the end of the report the project is evaluated and conclusions are drawn on what can be improved in the model, such as adding more streamlined updating of variant sequence.  Additionally future experiments that can be interesting to look at is specified based upon the results from the project.

No description available.

No description available.

No description available.

This paper presents a design optimisation of a mechanism used to lift and turn heavy objects, in this case, a specific gear that weights 3000 kg. The objective pursued during the development of the project was to reduce the weight of the mechanism, and thus, make it more cost-efficient, as well as to improve the clamping system to secure that the heavy objects are safely handled. The method followed was to first identify the critical parts in cooperation with the client. Then, the corresponding analysis has been developed for each of those parts, by minimising the mass of two of them, and by selecting and dimensioning the guideways for the clamping motion in the other case. The key results obtained from these analyses were that the weight of one of the parts was reduced by 50 %, the clamping system was improved and that the stress analysis shows that the maximum stress is far below acceptable levels. Hence, it is concluded that it was possible to optimise the mechanism and reduce the weight, improving the handling of heavy objects.

No description available.

The introduction of industry 4.0 initiated the vision of a smart factory with all the supplied characteristics of highly individualized processes connecting the real world with virtual reality. Collaboration between humans and machines has been desirable for a long time but the associated risks have been a restriction. The interaction between collaborative processes and virtual reality offers the possibility where new concepts and ideas can be developed in a safe and sustainable environment. The capability to reconstruct, evaluate and test new concepts and ideas without affecting the real world is desirable relative to the newly introduced awareness in sustainability. The purpose of this project is to investigate the possibilities regarding in what extent virtual reality can contribute when training operators, identifying possible improvements, identifying risks associated with ergonomics and assisting the simulation development. The projects associated company is located in Skövde and is regarded one of the leading companies within the vehicle manufacturing industry. The overall aim of the project is to develop a simulation environment using human-robot collaboration capable of interaction through virtual reality. Several limitations have been engaged in order to narrow the project scope down to a reasonable level. These limitations involve exclusively using Siemens Process Simulate software, HTC Vive for equipment regarding virtual reality and usage of Universal Robots UR10e as the collaborative robot. In order to construct the simulation environment in a good way and achieve the project aims a suitable methodology has been developed. The procedure started with an extensive literature review and theoretical framework in order to obtain the necessary knowledge in the area. Both qualitative and quantitative research methods have been used for gathering relevant information regarding necessary equipment and manufacturing operations. A summary of the collected data and theory resulted in a specification for the simulation environment prior to the construction phase. The two final versions of the simulation environment have successfully been able to achieve the project goals of training operators, possible improvement identification and ergonomics.

No description available.