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  • 1.
    Adane, Tigist Fetene
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology. KTH.
    Bianchi, Maria Floriana
    KTH, School of Industrial Engineering and Management (ITM).
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology. KTH, School of Industrial Engineering and Management (ITM), Centres, Design and Management of Manufacturing Systems, DMMS.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Performance evaluation of machining strategy for engine-block manufacturing2015In: Performance evaluation of machining strategy for engine-block manufacturing, ISSN 1895-7595, Vol. 15, no 4, p. 81-102Article in journal (Refereed)
    Abstract [en]

    This paper will introduce a novel methodology for the performance evaluation of machining strategies of engine block manufacturing. The manufacturing of engine components is vital to the automotive and vehicle manufacturing industries. Machining is critical processes in the production of these parts. To survive and excel in the competitive manufacturing environment, companies need to improve as well as update their machining processes and evaluate the performance of their machining lines. Moreover, the lines and processes have to be robust in handling different sources of variation over time that include such examples as demand fluctuations, work-piece materials or even any changes in design specifications. A system dynamics modelling and simulation approach has been deployed to develop a methodology that captures how machining system parameters from the machining process are interacted with each other, how these connections drive performance and how new targets affect process and machine tool parameters through time. The developed model could provide an insight of how to select the crucial machining system parameters and to identify the effect of those parameters on the output of the system. In response to such an analysis, this paper provides (offers) a framework to examine machining strategies and has presented model that is useful as a decision support system for the evaluation and selection of machining strategies. Here a system dynamics methodology for modelling is applied to the milling operation and the model is based on an actual case study from the engine-block manufacturing industry.

  • 2.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    A Computational Framework for Control of Machining System Capability: From Formulation to Implementation2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Comprehensive knowledge and information about the static and dynamic behaviour of machine tools, cutting processes and their interaction is essential for machining system design, simulation, control and robust operation in safe conditions. The very complex system of a machine tool, fixture and cutting tools during the machining of a part is almost impossible to model analytically with sufficient accuracy. In combination with increasing demands for precision and efficiency in machining call for new control strategies for machining systems. These strategies need to be based on the identification of the static and dynamic stability under both the operational and off-operational conditions. To achieve this it is necessary to monitor and analyze the real system at the factory floor in full production. Design information and operational data can then be linked together to make a realistic digital model of a given machining system. Information from such a model can then be used as input in machining simulation software to find the root causes of instability.

    The work presented in this thesis deals with the static and dynamic capability of machining systems. The main focus is on the operational stability of the machining system and structural behaviour of only the machine tool, as well.

    When the accuracy of a machining system is measured by traditional techniques, effects from neither the static stiffness nor the cutting process are taken into account. This limits the applicability of these techniques for realistic evaluation of a machining system’s accuracy. The research presented in this thesis takes a different approach by introducing the concept of operational dynamic parameters. The concept of operational dynamic parameters entails an interaction between the structural elements of the machining systems and the process parameters. According to this concept, the absolute criterion of damping is used to evaluate the dynamic behaviour of a machining system. In contrast to the traditional theory, this methodology allows to determine the machining system's dynamic stability, in real time under operating conditions. This framework also includes an evaluation of the static deformations of a machine tool.  In this context, a novel concept of elastically linked system is introduced to account for the representation of the cutting force trough an elastic link that closes the force loop. In addition to the elastic link which behaves as a static element, a dynamic non-contact link has been introduced. The purpose is to study the non-linear effects introduced by variations of contact conditions in joints due to rotational speed.

  • 3.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Model-Based Investigation of Machining Systems Characteristics: Static and Dynamic Stability Analysis2008Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The increasing demands for precision and efficiency in machining call for new control strategies for machining systems based on the identification of static and dynamic characteristics under operational conditions. By considering the machining system as a closed-loop system consisting of a machine tool structure and a machining process, the join system characteristics can be analyzed. The capability of a machining system is mainly determined by its static and dynamic stiffness.

    The goal of this thesis is to introduce some concepts and methods regarding the identification of machining system stability. Two methods are discussed, one for the static behaviour analysis of a machine tool, and one for dynamic stability of a machining system. Preliminary results are indicating unambiguous identification of capabilities of machining systems static and dynamic characteristics.

    The static behaviour of a machine tool is evaluated by use of a loaded double ball bar (LDBB) device. The device reproduces the real interaction between the join system, the machine tool elastic structure and the cutting process. This load is not equivalent to real cutting forces, but it does have a similar effect on the structure. This has been investigated both trough simulation and experimental work.

    It is possible to capture the process – ­machine interaction in a machining system by use of the model-based identification approach. The identification approach takes into consideration this interaction and can therefore be used to characterize the machining system under operational conditions. The approach provides realistic prerequisites for in-process machining system testing. The model parameters can be further employed for control and optimization of the cutting process. Using different classification schemes, the model-based identification method is promising for the detection of instability.

    Furthermore, it is the author’s belief that a model-based stability analysis approach is needed to exploit the full potential of a model driven parts manufacturing approach.

  • 4.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Prediction of machined part accuracy from machining system capability2014In: CIRP annals, ISSN 0007-8506, E-ISSN 1726-0604, Vol. 63, no 1, p. 505-508Article in journal (Refereed)
    Abstract [en]

    A novel methodology for linking machining system capability to the accuracy of a machined part is presented. Using special testing equipment, force-deviation functions in the real machine workspace are obtained. An elastically linked multi-body simulation and FE model evaluates the volumetric deviations. The deviation values are then calculated for a particular tool path. The forces and the deviations along the tool path are computed and compared with results obtained from machining experiments. This approach yields elimination of laborious machining experiments and supports an unequivocal control of machining system conditions giving the required level of part accuracy.

  • 5.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Daghini, Lorenzo
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Recursive estimation of machine tool structure dynamic properties2010In: CIRP International Conference on High Performance Cutting, / [ed] Tojiro Aoyama, Yoshimi Takeuchi, Gifu, 2010, p. 365-370Conference paper (Refereed)
    Abstract [en]

    In today’s highly competitive environment there is a need for fast and accurate methods to assess the capability of manufacturing units. The traditional estimation of the dynamic properties of machine tools is usually time consuming and assumes time-invariant properties. This paper introduces a method for analyzing machine tool structure dynamic properties by recursive estimation of modal and operational parameters. A contact-less excitation system and a specially designed tool were employed to enable spindle speed sweep. The primary contribution of this paper lies within the formulation and implementation of recursive parametric models for tracking the time-varying dynamic properties of a machine tool structure.

  • 6.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Daghini, Lorenzo
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Österlind, Tomas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Contactless excitation and response system for analysis of high precision rotor dynamic properties2013In: Laser Metrology and Machine Performance X: LAMDAMAP 2013 / [ed] Prof. Liam Blunt & Dr. Wolfgang Knapp, Bedfordshire, UK: euspen , 2013, p. 150-156Conference paper (Refereed)
    Abstract [en]

    The spindle system is a critical part of a machine tool structure and its dynamic properties are important for the performance of the whole machining system. Currently the only way to extract the dynamic properties of a given structure is via experimental modal analysis. This approach, however, can only be employed on idle systems and is performed with the assumption that the dynamics of a system are independent of rotational speed. The latter assumption cannot be applied to spindle systems. This paper introduces a novel testing system for analysing machine tool spindles dynamic properties, consisting of real-time recursive estimation of modal and operational dynamic parameters, employed alongside a contactless excitation and response system. The presented approach allows analysing the spindle system condition and dynamic properties not only at discrete rotational speed intervals but also during continuous sweep of rotational speed.

  • 7.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Laspas, Theodoros
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Accuracy and Performance Analysis of Machine Tools2019In: Metrology / [ed] Wei Gao, Singapore: Springer, 2019Chapter in book (Refereed)
    Abstract [en]

    The key to solve manufacturing quality and productivity problems in the machining of parts is to understand the physical attributes’ geometric/kinematic, static, dynamic, and thermal behavior of machine tools. In this chapter basic definitions, error sources, and instruments and methodologies for the identification and evaluation of machine tools’ physical attributes will be outlined.

    The first section presents the background and answers “why” it is important to measure and evaluate machine tools under no-load and loaded condition. Basic concepts and definitions of metrological terms will be given. In the second part, error sources in machine tools are introduced, and in the third part, instruments and methodologies for the accuracy evaluation of machine tools will be given.

  • 8.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Maffei, AntonioKTH, School of Industrial Engineering and Management (ITM), Production Engineering, Production Systems.
    Proceedings of the International Conference on Advanced Manufacturing Engineering and Technologies2013Conference proceedings (editor) (Refereed)
  • 9.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Accuracy analysis of machine tools using Elastically Linked Systems2013In: CIRP annals, ISSN 0007-8506, E-ISSN 1726-0604, Vol. 62, no 1, p. 503-506Article in journal (Refereed)
    Abstract [en]

    The paper introduces the concept of Elastically Linked Systems (ELS) to directly relate the machine tool positional and static accuracy to the machined part’s geometric errors and form deviation. Practical implementation of the ELS concept resulted in a novel test equipment, Loaded Double Ball Bar (LDBB) which is a precision mechatronic device with variable load. The test method based on the device is able to reveal machine tool characteristics not obtainable with existing methods as for instance the variation of stiffness in the entire working space. The LDBB is used to experimentally evaluate the stiffness and the corresponding accuracy of five machine tools.

  • 10.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Centres, Design and Management of Manufacturing Systems, DMMS. KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Centres, Design and Management of Manufacturing Systems, DMMS. KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Evaluation of machining system dynamic stiffness2007In: Swedish Production Symposium: Gothenburg, Sweden, 2007, 2007Conference paper (Refereed)
    Abstract [en]

    Today’s test methods are analysing machine tool specific characteristics but leaves out to a great deal the machining process. In this paper an evaluation method for determining machining system dynamic characteristics is discussed. For machine capability analysis, the overall elastic structure must be considered, i.e., machine tool – fixture – workpiece – toolholder – tool. Regarding dynamic behaviour of machining systems, the stability can only be evaluated through the interaction between the two subsystems, elastic structure and cutting process. In order to analyse the join machining system, stochastic discrete models, ARMA models are used to identify the stability of the join system, elastic structure – machining process.

  • 11.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Centres, Design and Management of Manufacturing Systems, DMMS. KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Centres, Design and Management of Manufacturing Systems, DMMS. KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Evaluation of machining system static stiffness2007In: Swedish Production Symposium: Gothenburg, Sweden, 2007, 2007Conference paper (Refereed)
    Abstract [en]

    The majority of test methods used for determine a machining systems status, are machine tool oriented and do not take into consideration the characteristics of the machining process. In this paper an evaluation method for determining a machining system static characteristics are discussed. The importance of joint stiffness and damping in elastic structures of machine tool is emphasized. In this context the new type of double ball bar (DBB) is described which applies a preload on the structure, thus creating more realistic conditions for accuracy measurements. Also, for machine capability analysis, the overall elastic structure must be considered, i.e., machine tool-fixture-workpiece-tool holder-tool.

  • 12.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Model-Based Identification of Dynamic Characteristics of the Join System Elastic Structure - Cutting Process2008In: The Internationl Swedish Production Symposium, Stockholm, 2008Conference paper (Refereed)
  • 13.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Model-based Identification of Dynamic Stability of Machining System2008In: 1st International Conference on Process Machine Interaction - Proceedings, 2008, p. 41-52Conference paper (Refereed)
  • 14.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Model-Based Identification of Manufacturing Processes Operational Dynamic Parameters2009In: The Annals of Univeritym of Galati / [ed] V. Paunoiu, Galati, 2009Conference paper (Refereed)
  • 15.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Recursive estimation of operational dynamic parameters in milling using acoustic signal2010In: International Conference on Process Machine Interactions / [ed] Y. Altintas, Vancouver, 2010Conference paper (Refereed)
    Abstract [en]

    The key concept of the identification procedure in this paper is to find a feature of the measured random response (sound pressure) that can be used to discriminate between stable and unstable process-machine interaction (PMI) in milling. The dynamic condition of the machining system is represented by the operational dynamic parameters (ODP), which refer to the contribution of the structural vibration modes and process vibration modes resulting during machining system operation. It is shown that the sound pressure level acquired by a microphone, located in the machine’s working area, is able to follow rapid changes in the process dynamics and therefore may be used as input in the recursive estimation scheme. The primary contribution of this paper lies within the formulation and implementation of recursive parametric models for the study of the real-time dynamics of a face milling operation PMI. A comparison between the experimental, simulated, and identified results is outlined.

  • 16.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Hjelm, Sven
    Scania CV AB, Production Engineering Research, Södertälje, Sweden.
    Johansson, Sverker
    CE Johansson AB, Eskilstuna, Sweden.
    Loaded double ball bar for capability testing of NC machine toolsManuscript (preprint) (Other academic)
    Abstract [en]

    This paper presents a novel test device for the evaluation of the accuracy of NC machine tools. The design concept is similar to a double ball bar (DBB) with the difference that an adjustable load generated by the device can be applied between spindle nose and machine tool table. This load eliminates the play existing in machine tool joints, thus reproducing the testing conditions that exist during machining. Collected data can be used to plot diagrams displaying important aspects of machine tool performance and a number of key figures such as static stiffness may be determined. The data can also be used for trend analysis; to predict any accuracy problems, and further to conduct preventive maintenance instead of emergency calls. The determined static behaviour could also be used to improve digital models for process simulations and compensation of errors caused by deflection.

  • 17.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Lundholm, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Virtual machining system engine for validation of realtime identification schems2011Conference paper (Refereed)
    Abstract [en]

    The aim of this paper is to introduce a novel methodology, based on a finite element (FE) computation engine for validating of real-time identification schemes applied in machining. FE modelling of the milling process has the purpose of being accountable for a thorough validation of the parametric identification approach, and of providing a good physical insight into the phenomena investigated. The system considered here has a lower number of degree-of-freedoms which permits a thorough analysis. However, when taking into account the system’s nonlinear and time-varying nature, it is clear that the results are far from being trivial. Therefore, the analysis of the milling process, taking into account nonlinearities restricting the growth of response amplitudes in the case of chatter-type instability, provides some intrinsic information of the basic features on the system that might be of both fundamental interest and practical use.

  • 18.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    A top-down equivalent stiffness approach for prediction of deviation sources in machine tool joints2017In: CIRP annals, ISSN 0007-8506, E-ISSN 1726-0604Article in journal (Refereed)
    Abstract [en]

    The accuracy of machine tools is affected to a large extent by the behavior of the system's joints. In this paper the equivalent stiffness approach identifies and calculates the contribution of joint error sources to the total deviation measured between toolholder and workpiece under loaded conditions. The force–deviation functions are measured at different locations in the machine workspace. Joint deviations are then computed and compared with results obtained from measurements. The results show the effectiveness of the proposed method in determining joint errors in machines.

  • 19.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nonparametric identificationof stiffness and damping in nonlinear machining systems2013In: / [ed] Andreas Archenti, Antonio Maffei, 2013, p. 317-327Conference paper (Refereed)
    Abstract [en]

    The demand for enhanced performance of production systems in terms of quality, cost and reliability is ever increasing while, at the same time, there is a demand for shorter design cycles, longer operating life, minimisation of inspection and maintenanceneeds. Experimental testing and system identification in operational conditions still represent an important technique for monitoring, control and optimization. The term identification refers in the present paper to theextraction of information from experimental data and is used to estimate operational dynamic parameters for machining system. Such approach opens up the possibility of monitoring the dynamics of machining system during operational conditions, and to be used for control and/or predictive purposes

  • 20.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Statistical dynamics – analysis of machining systems operational conditions2019In: Leading-edge research and engineering development whithin advanced chatter vibration theoryY / [ed] Yoshimi ITO, Japan: Machine Tool Engineering Foundation , 2019, 1, p. 118-191Chapter in book (Refereed)
    Abstract [en]

    In this chapter the subject of statistical dynamics are discussed and non-parametric and parametric models for machining system identification are derived. The common characteristic for all discussed models is that they may be used for computing the operational dynamic parameters (ODP) of the closed loop machining system. Though the input to these models originates from the machining operations, not all models can be implemented for real-time identification. Generally, non-parametric models may be used solely for off-line identification, i.e., first recording the vibration signal from machining operations and then analysing the signal and identifying the nature of the excitation. Parametric models implemented in recursive algorithms are used for real-time identification of machining systems dynamic characteristics. 

    The main objectives of the chapter are: (i) the development of parametric and non-parametric models based on identification techniques with the purpose of integrating into a single step within the estimation of dynamic parameters characterising the machining system, (ii) in non-parametric identification, implementing techniques for ODPs and random excitation estimation, (iii) in parametric identification, the development of the recursive computational model of the machining system based on the data obtained during the actual operational regime. Through these contributions, a step is taken beyond the classical approach to analyse the dynamics of a machining system by separately identifying the structural and process parameters. In the proposed process, the two substructures, tool/toolholder and workpiece/fixture, are coupled, in addition to the open loop (elastic structure of the machine tool), by a feedback loop closing the energy loop, through the thermoplastic chip formation mechanism.

    The machining system can only be completely analysed only in closed loop i.e. in operational conditions since specially designed off-line experiments with controlled input, such as modal testing, give the response from only the open loop.

  • 21.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Casterman, Guillaume
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Hjelm, Sven
    A new method for circular testing of machine tools under loaded condition2012In: Fifth CIRP Conference On High Performance Cutting 2012 / [ed] Konrad Wegener, Elsevier, 2012, p. 575-580Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel test device for the evaluation of the accuracy of machine tools. The design concept is similar to a double ball bar (DBB) with the difference that an adjustable load generated by the device can be applied between spindle nose and machine tool table. The device, called Loaded Double Ball Bar (LDBB), can be used either as an ordinary double ball bar system with no load applied to the structure, or with a predefined load applied to the structure. The load that is generated by the LDBB is generally not equivalent to real cutting forces. However, from the static deflection point of view the effect of the load on the machine tool structure has similar impact on the static behaviour of the system. For instance, the load can in some cases eliminate existing play in ball screws, plays that under normal machining condition will be eliminated by the effect of cutting forces on the structure. With the help of this test device, not only can the identifiable errors by an ordinary DBB be evaluated but also machine tool elastic deflection in different directions. It is also possible to track different error patterns to the applied load.

  • 22.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Lundholm, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Virtual Machining System Engine for Simulation of Process Machine Interaction2012In: Modern Machinery Science Journal, ISSN 1803-1269, Vol. March, p. 310-314Article in journal (Refereed)
    Abstract [en]

    The aim of this paper is to introduce a novel methodology, based on a finite element (FE) computation engine for simulation of process machine interaction occurring in machining systems. FE modelling of the milling process has the purpose of being accountable for a thorough validation of the parametric identification approach, and of providing a good physical insight into the phenomena investigated. The system considered here has a lower number of degree-of-freedoms which permits a thorough analysis. However, when taking into account the system’s nonlinear and time-varying nature, it is apparent that the results are far from being trivial. Therefore, the analysis of the milling process, taking into account nonlinearities restricting the growth of response amplitudes in the case of chatter-type instability, provides some intrinsic information of the basic features on the system that might be of both fundamental interest and practical use.

  • 23.
    Archenti, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Österlind, Tomas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Evaluation and Representation of Machine tool Deformations2011In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 11, no 4, p. 118-129Article in journal (Refereed)
    Abstract [en]

    This paper presents a novel test concept for the evaluation of the accuracy of NC machine tools. The evaluation of machine tools deformations is performed by help of a device similar to the double ball bar (DBB) with the difference that an adjustable load generated by the device can be applied between spindle nose and machine tool table. This load eliminates the play existing in machine tool joints, thus reproducing the testing conditions that exist during machining. Collected data are used to plot diagrams displaying characteristic aspects of achine tool performance and a number of key figures such as static stiffness may be etermined. The data can also be used for trend analysis; to predict any accuracy deviations, and further to conduct preventive maintenance instead of emergency calls. The determined static behaviour could also be used to improve digital models for process simulations and compensation of errors that are caused by deflection.

  • 24.
    Berglund, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Analytical Modelling of CGI Machining System Dynamic Behaviour2009In: Proceedings of The Internationl 3´rd Swedish Production Symposium / [ed] B.G. Rosén, Göteborg: The Swedish Production Academy , 2009, p. 348-357Conference paper (Refereed)
  • 25.
    Cedergren, Stefan
    et al.
    Department of Materials and Manufacturing Technology, Chalmers University of Technology, 41296, Gothenburg, Sweden, Research and Technology Centre, GKN Aerospace Engine Systems, 46181, Trollhättan, Sweden.
    Frangoudis, Costantinos
    KTH, School of Industrial Engineering and Management (ITM).
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Pederson, Robert
    Research and Technology Centre, GKN Aerospace Engine Systems, 46181, Trollhättan, Sweden.
    Sjöberg, Göran
    Research and Technology Centre, GKN Aerospace Engine Systems, 46181, Trollhättan, Sweden.
    Influence of work material microstructure on vibrations when machining cast Ti-6Al-4V2015In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, p. 1-15Article in journal (Refereed)
    Abstract [en]

    Titanium alloys are known to produce shear-localized chips during machining, resulting in cyclic variations in cutting forces which in turn could cause severe problems with vibrations. However, at low cutting speeds and feed rates, continuous chips are formed, with an increase in both parameters favoring the transition to shear-localized chips. This transition is affected by work material microstructure, where a coarse microstructure gives anisotropic effects, e.g., when the size of alpha colonies is on the same order of magnitude as the primary cutting zone. The change in chip morphology with an increase in cutting parameters will then be dependent on the orientation of alpha colonies within the cutting zone. The microstructure of work material can show large variations depending on product form, e.g., cast, wrought, or sheet material, thus affecting whether the chip formation is isotropic or anisotropic. Other sources of variations also exist that can be found within the same component, such as segregation of alloying elements and differences in thermo-mechanical history during processing due to geometry. In this study, the interaction between work material microstructure, process parameters, and the machining system’s structural characteristics is studied. The aim is to further increase the knowledge about vibrations during machining of titanium and the role of microstructure and machining system properties. Different microstructures were produced by adding boron to cast Ti-6Al-4V material, where the resulting colony sizes gave both isotropic and anisotropic chip formation within the chosen cutting data range. The machining systems dynamic properties were varied by using different tool overhangs, thereby simulating different configurations of natural frequencies and stiffness. The results show the influence of both microstructure and machining system’s structural characteristics on the dynamic response of the system for different process parameters. This information can be used to increase robustness of machining operations taking into consideration this three-way relationship.

  • 26.
    Daghini, Lorenzo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Design and Dynamic Characterization of Composite Material Dampers for Parting-Off Tools2010In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 10, no 2, p. 57-70Article in journal (Refereed)
  • 27.
    Daghini, Lorenzo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Design, Implementation and Analysis of Composite Material Dampers for Turning Operations2009In: International Conference on Mechanical Engineering, 2009, p. 613-620Conference paper (Refereed)
    Abstract [en]

    This paper introduces a novel design for boring bar with enhanced damping capability. The principle followed in thedesign phase was to enhance the damping capability minimizing theloss in static stiffness through implementation of composite materialinterfaces. The newly designed tool has been compared to a conventional tool. The evaluation criteria were the dynamic characteristics, frequency and damping ratio, of the machiningsystem, as well as the surface roughness of the machined workpieces.The use of composite material in the design of damped tool has been demonstrated effective. Furthermore, the autoregressive moving average (ARMA) models presented in this paper take in to consideration the interaction between the elastic structure of themachine tool and the cutting process and can therefore be used to characterize the machining system in operational conditions.

  • 28.
    Daghini, Lorenzo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Rashid, Amir
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Nicolescu, Cornel-Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Active alignment chuck for ultra precision machining2011In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 11, no 4, p. 39-48Article in journal (Refereed)
    Abstract [en]

    Ultraprecision (UP) components have become common in everyday life products such as mobile phones or compact high resolution digital cameras. Thus the need of producing such components with high accuracy and low production cost. UP machine tools are capable of extremely high accuracy in tool positioning but still today the workpiece is positioned by hand, hence the high production cost of UP components. A fully automated chain of production has been developed within the EU-IP project “Production 4 micro”. This paper describes the active alignment chuck for workholding in UP machining. The chuck has been provided with a high damping interface (HDI) and to evaluate its efficiency the chuck has undergone an experimental modal analysis (EMA) as well as machining tests. The chosen operation was grooving by fly cutting using a diamond tool. The EMA showed that the HDI was effective for those modes where there was relative displacement between one side and the other of the HDI. This result was confirmed by the machining tests as well. The HDI resulted being effective in damping high frequency modes (around 4 – 5 kHz), hence one expected benefit would be a longer tool life.

  • 29.
    Daghini, Lorenzo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Österlind, Tomas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Extending stability limits by designed-in damping2013In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 13, no 1, p. 37-48Article in journal (Refereed)
    Abstract [en]

    With advances in material technology come challenges to productivity. New materials are, in fact, more difficult to machine with regards to tool wear and especially machine tool stability. This paper proposes to extend the stability limits of the machining system by enhancing the structure’s damping capability. The aim of the research work presented here is to introduce a unified concept based on the distribution of damping within the machining system components exploiting the dynamic properties of the existing joints. To maintain a high level of static stiffness, it was chosen to adapt hydrostatic clamping systems to the tools. Damping is designed in the structure via high damping interfaces (HDI), intentionally introduced interfaces where the damping ratio is enhanced by introduction of viscoelastic polymer metal composites between the two metallic surfaces composing the interface. In this paper HDI are introduced at two joints, between tool and turret and between turret and lathe. The tests show that the designed-in damping is effective and allows extending the stability limits of the machining system. The implementation of designed-in damping allows the end user to select the most suitable parameters in terms of productivity avoiding the hassle of tuning the devices, having to acquire a deep knowledge in structural dynamics or having to use additional control systems. In addition to this, the enhanced machine tool system becomes less sensitive to stability issues provoked by difficult-to-machine materials or even fluctuations of the work material properties that might occur in everyday production processes.

  • 30.
    Hedlind, Mikael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Computer Systems for Design and Manufacturing.
    Lundgren, Magnus
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Computer Systems for Design and Manufacturing.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Kjellberg, Torsten
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Computer Systems for Design and Manufacturing.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Manufacturing resource modelling for model driven operation planning2010In: Process Machine Interactions (PMI): Vancouver, Canada, June 10-11, 2010 / [ed] Prof. Y. Altintas, University of British Columbia, 2010Conference paper (Refereed)
    Abstract [en]

    Models of manufacturing resources as machine tools, fixtures and cutting tools contribute to efficient and simplified operation planning. With operation planning domain concept, defined in ontology and used during modelling of coherent ISO 10303-214 conforming data models of manufacturing resources, stable implementation solutions are ensured while capable of representing current manufacturing resources and resources developed in the future. Using similarities between different types of resources, a unified modelling approach may be applied independent of the type of object. Information classes as interfaces, kinematics, performance and behavior are identified and related to corresponding construct of the standardized product generic schema. With the common representation of shared information between applications domains as operation planning, maintenance and factory layout design, presented result contributes to set the basis for a digital factory used in virtual manufacturing to continuously improve the production system.

     

  • 31.
    Kayol, Bassam
    et al.
    KTH.
    Abu-Ghunmi, Diana
    Abu-Ghunmi, Lina
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM).
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM).
    Larkin, Charles
    Corbet, Shaen
    An economic index for measuring firm's circularity: The case of water industry2019In: Journal of Behavioral and Experimental Finance, ISSN 2214-6350, E-ISSN 2214-6369, Vol. 21, p. 123-129Article in journal (Refereed)
    Abstract [en]

    Transition toward circular-economy model is a must to sustain the planet sources. Under circular economy model wastewater is transformed from a ste into a resource. Therefore, a comprehensive circular economy dex; the Circonomics Index, is proposed to measure circularity of stewater industry. The component indicators of the index are linked rectly to the three Rs; reduce, reuse and recycle, of circular onomy. The novelty of the proposed Index is that it uses objectively nstructed weights that reflect the environmental benefits of the eatment process, and the index captures the reuse and recycling ficiency of an WWTP, which reflect the specific nature of wastewater. e findings show that treatment technology is a major factor in termining the production efficiency, reuse rate and recycling rformance of a WWTP. The results of using the Circonomics Index have ofound implication for policy makers to speed up the process of moving a circular economy.

  • 32.
    Krajnik, Peter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Pusavec, Franci
    University of Ljubljana, Faculty of Mechanical Engineering, Slovenia.
    Kopac, Janez
    University of Ljubljana, Faculty of Mechanical Engineering, Slovenia.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Investigation of Cryogenic Cooling Lubrication Effect on Machining System Operational Damping Ratio using Acoustic Signal2010In: CIRP International Conference on High Performance Cutting / [ed] Tojiro Aoyama, Yoshimi Takeuchi, 2010, p. 61-64Conference paper (Refereed)
  • 33.
    Laspas, Theodoros
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Investigation of multi-axis system static and kinematic characteristics2016Conference paper (Refereed)
    Abstract [en]

    Multi-axis machine tools performance is essential in achieving high positioning accuracy at the desired feed rate and to withstand mechanical loads induced by the process-machine interaction. In this regard evaluation and characterization of multi-axis machine performance in terms of kinematic and static accuracy under variable load operating conditions poses a challenge.The paper aims to investigate and characterize the kinematic and static accuracy of a multi-axis milling centre under loaded conditions. Employing the concept of Elastically Linked System (ELS) for “off-operational” evaluation, the accuracy due to the interaction between the machine’s structure the machining process loads and the control system is assessed. Using the Loaded Double Ball Bar (LDBB) measurement system the cutting process is emulated by inserting an “elastic link” between the tool and the workpiece that closes the force-loop of the system.A set of workspace positions is selected to perform the LDBB measurements. The positions are selected so as to cover an adequate region of the effective machining workspace and at the same time utilizing a combination of linear and rotational axis positions and orientations to allow the investigation of their behavior and the effect of the machine structure. The captured deformations and their variation within the examined workspace region give a comprehensive view of the machine’s kinematic and static accuracy under the effect of the load induced errors and kinematic inaccuracies.

  • 34.
    Leonesio, Marco
    et al.
    CNR Institute of Industrial Technology and Automation, Milan, Italy.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Parenti, Paolo
    Department of Mechanical Engineering, Polimi, Milan, Italy.
    Parametric and non-parametric identification of micromilling dynamics2015In: Proceedings of the 4M/ICOMM2015 Conference / [ed] Massimiliano Annoni et al, 2015, p. 121-125Conference paper (Refereed)
    Abstract [en]

    Monitoring and control of micromilling process represents a challenging task in metal cutting. The lack of static and dynamic stiffness due to the small tool size represents one of the most important issues that has to be tackled in order to provide satisfactory control of the process. In this paper different methods for identifying micro-end milling dynamics for process monitoring are proposed. On one side a parametric approach based on the identification of machining system ODPs (Operation Dynamic Parameters) has been designed. On the other hand a non-parametric approach, based on the calculation of system Lyapunov exponents has been also tested to verify whether generalized methods for assessing system dynamics are also applicable in micromachining where the process non-linearity’s can become relevant, thus limiting the effectiveness of other monitoring methods.

  • 35.
    Maffei, Antonio
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Daghini, Lorenzo
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Lohse, N.
    Loughborough University.
    CONALI Ontology. A Framework for Design and Evaluation of Constructively Aligned Courses in Higher Education: Putting in Focus the Educational Goal Verbs2016In: Procedia CIRP, Elsevier, 2016, p. 765-772Conference paper (Refereed)
    Abstract [en]

    An increasing number of Higher Education professionals have embraced the Constructivism theory in contrast with the traditional transmissive pedagogy approach where the focal figure is the teacher. Constructivists emphasizes that the learners acquire, or construct, knowledge through their own activities and previous knowledge. Teacher role is to set up an environment that can provide a good learning experience for the students. In view of this the alignment of the intended learning outcome (ILO) with the teaching and learning activity (TLA) and the assessment task (AT) of the course becomes an important requirement for good learning. The driver of the alignment is the educational goal verb (EGV) that represents the educational goal underling a specific intended learning outcome (ILO). This verb should be elicited by the course's TLA and be the base for the consequent AT. The convergence of constructivism with this concept generates the constructive alignment pedagogical paradigm. The CONALI ontology answers the requirement for a structured framework to describe the vast body of knowledge developed in such a field. The salient aspects of constructive alignment have been extracted and classified in a comprehensive taxonomy. The following description of the semantic relationships among the different classes resulted in the CONALI ontology. The chosen modelling language is OWL: this provides the possibility to describe in a computer understandable way a higher education courses to an unprecedented level of detail. OWL enables also the creation of a specific knowledge base by populating the model. The knowledge base can then be analysed and interrogated on many important issues concerning the alignment of the instantiated course. The CONALI ontology becomes an important tool to design and synthesize the related domain knowledge. This paper proves the usability of CONALI ontology as tool to represent the courses in an engineering program and evaluate the alignment of their activities. The specific instantiation is based on the Industrial Engineering program at KTH Royal Institute of Technology in Stockholm, Sweden.

  • 36.
    Nicolescu, Mihai
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Dynamic parameter identification in nonlinear machining systems2013In: Journal of Machine Engineering, ISSN 1426-708X, Vol. 13, no 3, p. 91-116Article in journal (Refereed)
    Abstract [en]

    The demand for enhanced performance of production systems in terms of quality, cost and reliability is ever increasing while, at the same time, there is a demand forshorter design cycles, longer operating life, minimisation of inspection and maintenance needs. Experimental testing and system identification in operational conditionsstill represent an important technique for monitoring, control andoptimization. The term identification refers in the present paper to the extraction of information from experimental data and is used to estimate operationaldynamic parameters for machining system. Such approach opens up the possibility of monitoring the dynamics of machining system during operational conditions, and to be used for control and/or predictive purposes. Machining system is considered non-linear and excited by random loads. Parametric and non-parametric techniques are developed for the identification of the non-linear machiningsystem and their application is demonstrated both by numerical simulations and in actual machining operations. Discrimination between forced and self-excitedvibration is also presented. The ability of the developed methods to estimate operational dynamic parameters ODPs is presented in practical machining operations.

  • 37.
    Nicolescu, Mihai
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Frangoudis, C.
    KTH.
    Semere Tesfamariam, Daniel
    KTH, School of Industrial Engineering and Management (ITM).
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Rashid, Amir
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    New Paradigm in Control of Machining System’s Dynamics2015In: Journal of Machine Engineering, Vol. 15, no 3Article in journal (Refereed)
    Abstract [en]

    The increasing demands for precision and efficiency in machining call for effective control strategies based on the identification of static and dynamic characteristics under operational conditions. The capability of a machining system is significantly determined by its static and dynamic stiffness. The aim of this paper is to introduce novel concepts and methods regarding identification and control of a machining system’s dynamics. After discussing the limitations in current methods and technologies of machining systems’ identification and control, the paper introduces a new paradigm for controlling the machining system dynamics based on design of controllable structural Joint Interface Modules, JIMs, whose interface characteristics can be tuned using embedded actuators. Results from the laboratory and industrial implementation demonstrate the effectiveness of the control strategy with a high degree of repeatability.

  • 38.
    rashid, Md.Masud-Ur
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Manufacturing and Characterization of a Carbon-Based Amorphous (a-CNX) Coating Material2018In: Nanomanufacturing and Metrology, ISSN 2520-8128, Vol. 1, no 1, p. 1-14Article in journal (Refereed)
    Abstract [en]

    A thick 400-micron amorphous carbon nitride (a-CNX ) coating material was synthesized by means of plasma-enhanced chemical vapor deposition process. High-power impulse magnetron sputtering technique was used to sputter a pure graphite target plate in reactive argon (Ar), nitrogen (N2 ) and acetylene (C2 H2 ) environment for depositing the omposite coating. Structural and chemical/elemental composition of the a-CNX  composite material was investigated by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and micro-Raman spectroscopy. The rootmean-square surface roughness (Sq ) and structure were estimated by atomic force microscopy. Mechanical properties such as hardness and Young’s modulus (Oliver–Pharr method) at room temperature were characterized by Vickers microindentation test. Operational temperature test of the deposited a-CNX  coating reveals that it can withstand up to 400 C without cracking. An inverted shaker test, based on central impedance method, was adopted to investigate the dynamic damping property of the coating material, and it was found that the first bending mode damping lossfactor of the reported a-CNX  coating is 0.015 ±  0.001 and corresponding loss modulus (Young’s modulus multiplied by lossfactor) is 0.234 ±  0.011 GPa.

  • 39. Rastegari, A.
    et al.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Online vibration condition monitoring of gas circulation fans in hardening process2018In: International Journal of COMADEM, ISSN 1363-7681, Vol. 21, no 1, p. 25-29Article in journal (Refereed)
    Abstract [en]

    Vibration analysis and the Shock Pulse Method (SPM) are two of the most popular condition monitoring techniques used in Condition-Based Maintenance (CBM) policy, especially for rotating equipment. To illustrate the extent to which advanced CBM techniques (in this case, vibration analysis and SPM) are applicable and cost effective in a manufacturing company, a pilot project was followed in real time. The pilot project was performed at a large manufacturing site in Sweden. The purpose of the project was to implement online condition monitoring of five critical gas circulation fans in the hardening process of the manufacturing company. This paper presents some of the main findings of the online condition monitoring of the fans for a period of three years. Consequently, based on the empirical data, the company was able to gain great profit due to preventing production losses by preventing breakdowns of the fans.

  • 40. Rastegari, Ali
    et al.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Online Condition Monitoring of Gas Circulation Fans in Hardening Process2016In: Congress Proceedings of COMADEM 2016, International Congress of Condition Monitoring and Diagnostics Engineering Management COMADEM 2016, 2016, 2016Conference paper (Refereed)
    Abstract [en]

    Vibration analysis and the Shock Pulse Method (SPM) are two of the most popular condition monitoring techniques used in Condition-Based Maintenance (CBM) policy, especially for rotating equipment. To illustrate the extent to which advanced CBM techniques (in this case, vibration analysis and SPM) are applicable and cost effective in a manufacturing company, a pilot pro-ject was followed in real time. The pilot project was performed at a large manu-facturing site in Sweden. The purpose of the project was to implement online condition monitoring of five critical gas circulation fans in the hardening pro-cess of the manufacturing company. This paper presents some of the main findings of the online condition monitor-ing of the fans for a period of two years. Consequently, based on the empirical data, the company was able to gain great profit due to preventing production losses by preventing breakdowns of the fans.

  • 41.
    Rastegari, Ali
    et al.
    Maintenance department, Volvo Group Trucks Operations.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Mohammadsadegh, Mobin
    Department of Industrial Engineering, Western New England University.
    Condition Based Maintenance of Machine Tools: Vibration Monitoring of Spindle Units2017Conference paper (Refereed)
    Abstract [en]

    Machining systems (i.e., machine tools, cutting processes and their interaction) cannot produce accurate parts if performance degradation due to wear in their subsystems (e.g., feed-drive systems and spindle units) is not identified, monitored and controlled. Appropriate maintenance actions delay the possible deterioration and minimize/avoids the machining system stoppage time that leads to lower productivity and higher production cost. Moreover, measuring and monitoring machine tool condition has become increasingly important due to the introduction of agile production, increased accuracy requirements for products and customers' requirements for quality assurance.Condition Based Maintenance (CBM) practices, such as vibration monitoring of machine tool spindle units, are therefore becoming a very attractive, but still challenging, method for companies operating high-value machines and components. CBM is being used to plan for maintenance action based on the condition of the machines and to prevent failures by solving the problems in advance as well as controlling the accuracy of the machining operations. By increasing the knowledge in this area, companies can save money through fewer acute breakdowns, reduction in inventory cost, reduction in repair times, and an increase in the robustness of the manufacturing processes leading to more predictable manufacturing. Hence, the CBM of machine tools ensures the basic conditions to deliver the right ability or capability of the right machine at the right time. One of the most common problems of rotating equipment such as spindles is the bearing condition (due to wear of the bearings). Failure of the bearings can cause major damage in a spindle. Vibration analysis is able to diagnose bearing failures by measuring the overall vibration of a spindle or, more precisely, by frequency analysis.Several factors should be taken into consideration to perform vibration monitoring on a machine tool’s spindle. Some of these factors are as follows: the sensor type/sensitivity, number of sensors to be installed on the spindle in different directions, positioning of the vibration accelerometers, frequency range to be measured, resonance frequency, spindle rotational speed during the measurements, measurement condition, including the no-load condition with tool clamped or without a tool, measuring tools and technologies, automatic or manual run of measurement, measurement routine, warning limits, and data handling and analysis, among other factors.The aim of this paper is thus to address CBM and particularly the implementation in the manufacturing industries focusing on the use of vibration monitoring techniques to monitor the condition of the machine tools’ spindle units. To conduct this study, a pilot project was followed in real time. The pilot project was performed at a manufacturing company in Sweden. The company’s product is gearboxes for the automotive industry, with a production volume of approximately 135,000 units per year. CBM, by on-line and off-line condition monitoring, using vibration monitoring, has been implemented on different types of machine tools, including horizontal and vertical turning machines, multi-task milling machines and grinding machines.

  • 42.
    Sadasivam, Logesh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Sandberg, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Machine tool ability representation: A review2018In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 18, no 2, p. 5-16Article in journal (Refereed)
    Abstract [en]

    Smart manufacturing and predictive maintenance are current trends in the manufacturing industry. However, the holistic understanding of the machine tool health condition in terms of accuracy, functions, process and availability is still unclear. This uncertainty renders the development of models and the data acquisition related to machine tool health condition ineffective. This paper proposes the term machine tool ability as an interconnection between the accuracy, functions, the process and the availability to overcome the lack of the holistic understanding of the machine tool. This will facilitate the further development of qualitative or quantitative methods as well as models. The research highlights the challenges and gaps to understand the machine tool ability.

     

  • 43.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Andreas, Archenti
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Utilization of machine tool repeatability in kinematic modelling2017In: Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 20172017, euspen , 2017, p. 49-50Conference paper (Refereed)
    Abstract [en]

    Modelling of non-systematic variations in the positioning performance of machine tools can support the understanding of capability variation in manufacturing processes. Kinematic characterisation is implemented through repeated measurements, which include variations connected to the performance of the machine tool. This paper addresses the integration of the positional repeatability to kinematic modelling through the utilization of direct measurement results. The statistical population of random errors along the single-axis travel first requires the proper management of experimental data. In this paper a methodology is presented for the determination of repeatability under static and unloaded conditions as an inhomogeneous parameter in the workspace. In a case study the component errors of a linear axis were investigated with repeated laser interferometer measurements to quantify the estimated repeatability and express it in the composed repeatability budget. The conclusions of the proposed methodology outline the sensitivity of kinematic models relying on measurement data, as the repeatability of the system can be in the same magnitude as systematic errors.

  • 44.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Utilization of Multi-Axis Positioning Repeatability Performance in Kinematic Modelling2018In: International Journal of Automation Technology, ISSN 1881-7629, E-ISSN 1883-8022Article in journal (Refereed)
    Abstract [en]

    Detailed description of multi-axis repeatability performance and modelling of non-systematic variations in the positioning performance of machine tools can support the understanding of root-causes of capability variations in manufacturing processes. Kinematic characterization is implemented through repeated measurements, which include variations connected to the performance of the machine tool. This paper addresses the integration of the positional repeatability to kinematic modelling through the employment of direct measurement results. The findings of this research can be used to further develop standardized approaches. The statistical population of random errors along the multi-axis travel first requires the proper management of experimental data. In this paper a methodology and its application is presented for the determination of repeatability under static and unloaded conditions as an inhomogeneous parameter in the work space. The work is exemplified in a case study, where the component errors of a linear axis were investigated with repeated laser interferometer measurements to quantify the estimated repeatability and express it in the composed repeatability budget. The conclusions of the proposed methodology outline the sensitivity of kinematic models relying on measurement data, as the repeatability of the system can be in the same magnitude as systematic errors.

  • 45.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology. KTH, School of Industrial Engineering and Management (ITM), Centres, Design and Management of Manufacturing Systems, DMMS.
    Vogl, Gregory W.
    NIST, Engn Lab, 100 Bur Dr, Gaithersburg, MD 20899 USA..
    Donmez, M. Alkan
    NIST, Engn Lab, 100 Bur Dr, Gaithersburg, MD 20899 USA..
    Identification of machine tool squareness errors via inertial measurements2019In: CIRP annals, ISSN 0007-8506, E-ISSN 1726-0604, Vol. 68, no 1, p. 547-550Article in journal (Refereed)
    Abstract [en]

    The accuracy of multi-axis machine tools is affected to a large extent by the behavior of the system's axes and their error sources. In this paper, a novel methodology using circular inertial measurements quantifies changes in squareness between two axes of linear motion. Conclusions are reached through direct utilization of measured accelerations without the need for double integration of sensor signals. Results revealed that the new methodology is able to identify squareness values verified with traditional measurement methods. The work supports the integration of sensors into machine tools in order to reach higher levels of measurement automation. behalf of CIRP.

  • 46.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Dax, Paul
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Degen, Florian
    Mikael, Hedlind
    Scania CV AB.
    Integration of machining system capability information into a CAx software environment for complex tool trajectory prediction2018In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271Article in journal (Refereed)
    Abstract [en]

    Integration of machine tool specific capability information related to a manufactured part’s accuracy can significantly support the decision-making in production, help to understand root-cases of quality loss and optimize cutting processes. In this paper, a systematic methodology is proposed to bridge the gap between machine tool specific capability and finished part’s accuracy. For this purpose, a measurement-based model is implemented in a CAx software environment for the prediction of geometrical deviations in complex milling processes. Results are presented in a case study to demonstrate errors on the workpiece level due to the quasi-static capabilities of a given machine tool.

  • 47.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Laspas, Theodoros
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Measurement and analysis of machine tool errors under quasi-static and loaded conditions2018In: Precision engineering, ISSN 0141-6359, E-ISSN 1873-2372, Vol. 51, p. 59-67Article in journal (Refereed)
    Abstract [en]

    Machine tool testing and accuracy analysis has become increasingly important over the years as it offers machine tool manufacturers and end-users updated information on a machine’s capability. A machine tooĺs capability may be determined by mapping the distribution of deformations and their variation range, in the machine tool workspace, under the cumulative effect of thermal and mechanical loads. This paper proposes a novel procedure for the prediction of machine tool errors under quasi-static and loaded conditions. Geometric errors and spatial variation of static stiffness in the work volume of machines are captured and described through the synthesis of bottom-up and top-down model building approaches. The bottom-up approach, determining individual axis errors using direct measurements, is applied to estimate the geometric errors in unloaded condition utilizing homogeneous transformation matrix theory. The top-down approach, capturing aggregated quasi-static deviations using indirect measurements, estimates through an analytical procedure the resultant deviations under loaded conditions. The study introduces a characterization of the position and direction dependent static stiffness and presents the identification how the quasi-static behavior of the machine tool affects the part accuracy. The methodology was implemented in a case study, identifying a variation of up to 27% in the stiffness response of the machine tool. The prediction results were experimentally validated through cutting tests and the uncertainty of the measurements and the applied methodology was investigated to determine the reliability of the predicted errors.

  • 48.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Laspas, Theodoros
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Measurement uncertainty associated with the performance of machine tool under quasi-static loaded test condition2017In: Laser Metrology and Machine Performance XII / [ed] L. Blunt & W. Knapp, Renishaw Innovation Centre, UK, 2017Conference paper (Refereed)
    Abstract [en]

    For proper characterisation of different physical quantities in machine tools, it is necessary to report the uncertainties associated to the measurements. The uncertainty evaluation, according to international standards, expresses information of the quality and the reliability of the measurement result. Applications like calibration and compensation are sensitive for the quality of the input data, thus the reliability of the characterisation results need to be interpreted accurately to avoid significant residual errors or overcompensation. General approaches take several factors into consideration during the estimation of measurement uncertainty such as the environmental variations or the uncertainties of the measurement device or the setup. At the same time, various reproducible and non-reproducible error sources associated to the performance testing of the machine tool are ignored. The reason behind it can be the lack of the applicable standardized measurement instruments.

    This paper highlights the significance of the uncertainty sources connected to the performance of the machine tool under quasi-static loaded condition. The variation of the static stiffness of machine tools, the hysteresis and play in the system can be even more significant uncertainty sources than the above mentioned ones. Under the framework of elastically linked systems (ELS), a circular test device, the loaded double ball bar (LDBB), is used in a case study to identify this effect. The LDBB can be used as a double ball bar, with the additional capability of applying a load, thus it enables the measurement of machine tool deviations under quasi-static loaded conditions. A measurement methodology is proposed to properly describe and demonstrate the variation of the contributing uncertainties associated with repeatability performance of the machine tool. With this approach important interdependencies can be expressed as uncertainty sources.

  • 49.
    Szipka, Karoly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Theodoros, Laspas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Prediction of machine tool errors under quasi-static condition2016Conference paper (Refereed)
  • 50.
    Szipka, Károly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Archenti, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Procedure for integration of measuring systems into manufacturing2018In: European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 18th International Conference and Exhibition, EUSPEN 2018, euspen , 2018, p. 167-168Conference paper (Refereed)
    Abstract [en]

    Modern production processes require shorter quality control loops and advanced adaptation to variations in production conditions. Thus, the demand to integrate and optimize measuring systems into production and raise the awareness in the management of uncertainty increases significantly. In the competitive edge of production, uncertainty is not solely object of evaluation but the result of a systematic optimization procedure, in which the selection of proper measuring system with suitable measurement uncertainty plays an inevitable role. This importance and highly developed analysis methods in the state of art make measurement uncertainty an effective basis for decision making related to the different aspects of integration. In this paper an iterative procedure is presented for systematic integration of measuring systems into production. The basis of decisions in the procedure is the "cost of uncertainty", which is estimated after technological assessment. The goal is to select an adequate measurement system for a given measurement task with appropriate metrological properties and set up an uncertainty budget, with components on an optimal level of elaboration. In a case study one possible application is shortly presented.

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