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  • 1.
    Aguilar Gómez, Raquel
    University West, Department of Engineering Science, Division of Automation Systems.
    Investigation of a Flexible Manufacturing Scenario for Production Systems: Case study: GKN Aerospace Company2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays the globalization of the market has a direct impact to the companies. On one hand, gives them the opportunity to spread their business but on the other hand increases the competition and the efforts to succeed. This project is pursuing to investigate and design a system capable to take upon and optimize the production within functional shops by in-troducing automation. Although the system it would be a standard solution for the functional shops, a case study for GKN Aerospace Company with its specifications has been carried out. The task become trickier due to the aeronautic sector requires a lot of work and effort to produce their products. The items and materials are expensive as well as the processes and treatments thus the introduction of automation is quite complex. This case study has accom-plished a research through the concepts and options to introduce automation within this production process. Taking under consideration the costs and efforts that would demand the investment for automation, the project propose a new and innovative manufacturing system "Move & Play", suitable with the features and requirements GKN Aerospace Company may need.The system proposed has been designed regarding to features such as movability, modularity and flexibility. These features have been considered essentials in order to make the system worth it and cost effective. The job-shop approach that the company use in its production contemplate the continuous change of products and introduction of new ones. Hence, the idea is to use the "Move & Play" system when it is required along the production. As a consequence, this system will create a "local product flow" along that point in the production that will organize the rest of the production or "global flow". Moreover it is expected to apply the concept of "plug-in" the processes that the system need at each time and therefore give flexibility to the system. With that purposes, the work has studied three different designs of the "Move & Play" system. Each design have considered different aspects and disposition. These designs have been compared according with criteria such as geometrical, the capacity and investment needed and the cycle time spent. Finally a conclusion on which design is the most suitable has been stated as well as a future work to continue with the work has been proposed.

  • 2.
    Andersson, Andreas
    University West, Department of Engineering Science, Division of Automation Systems.
    Utredning av variablerna som påverkar storleken på brytspänningen i lindningskopplare2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The recovery voltage is the voltage that occur when the transition resistor in the tap-changer leaves its previous position during an operation cycle. The amplitude of the recovery voltage depends on the leakage inductance.

    If the leakage inductance is unknown, the recovery voltage can instead be calculated using a FEM-program called ACE (internal ABB-program) in conjunction with Mathcad. First, the reactances between the windings are calculated in per unit (p.u) using ACE and they depend on the winding layout. It is time consuming to use ACE and Mathcad and the task has been to investigate the parameters that affects the recovery voltage and to develop a simplified calculation of it.

    Through simulation using ACE of a number of different winding layouts one soon comes to the conclusion that there are simply too many parameters affecting the reactances. Although the simplified calculations that despite this has been developed, they soon prove to be too rough to be useful. Mathcad is even more complex with heavy calculations that are not easy to grasp.

    However, this thesis has given more knowledge about the way the reactances are affected by the geometry of the windings, even though it was not possible to in a reasonable way simplify the calculation of ACE and Mathcad.

  • 3.
    Antoine, Galluet
    University West, Department of Engineering Science, Division of Automation Systems.
    Kinect to control robot: New ways to interact with robots2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The main goal of the thesis is to create a way to interact with a ABB robot by using a Kinect.The focus will be put on making the robot mimicking the user's arm movement. But otherway like voice control will be investigated.Two main part of the work are developed in this report. The first one is the software aroundthe Kinect to get the body data. The software developed provides the user a visual feedbackon what the Kinect see and allows him to choose what mode he wants to use. Two mainmode are implemented. A mimicking one which makes the robot mimicking the chosen armand a moving object mode which tell the robot to go to the user's position and set the toolas the user hand state.When all the data are gathered, they are sent to the robot using an IP socket and predefinedmessage to give him the desired order.

  • 4.
    Augustsson, Svante
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Gustavsson Christiernin, Linn
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation Systems.
    Human and robot interaction based on safety zones in a shared work environment2014In: HRI '14: Proceedings of the 2014 ACM/IEEE international conference on Human-robot interaction, New York: Association for Computing Machinery (ACM), 2014, p. 118-119Conference paper (Refereed)
    Abstract [en]

    In this paper, early work on how to implement flexible safety zones is presented. In the case study an industrial robot cell emulates the environment at a wall construction site, with a robot performing nailing routines. Tests are performed with humans entering the safety zones of a SafetyEye system. The zone violation is detected, and new warning zones initiated. The robot retracts but continues its work tasks with reduced speed and within a safe distance of the human operator. Interaction is achieved through simultaneous work on the same work piece and the warning zones can be initiated and adjusted in a flexible way.

  • 5.
    Augustsson, Svante
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Olsson, Jonas
    University West, Department of Engineering Science, Division of Manufacturing Processes. University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Gustavsson Christiernin, Linn
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    How to Transfer Information Between Collaborating Human Operators and Industrial Robots in an Assembly2014In: Proceedings the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational, 2014, p. 286-294Conference paper (Refereed)
    Abstract [en]

    Flexible human-robot industrial coproduction will be important in many small and middle-sized companies in the future. One of the major challenges in a flexible robot cell is how to transfer information between the human and the robot with help of existing and safety approved equipment. In this paper a case study will be presented where the first half focus on data transfer to the robot communicating the human's position and movements forcing the robot to respond to the triggers. The second half focuses on how to visualize information about the settings and assembly order to the human. The outcome was successful and flexible, efficient coproduction could be achieved but also a number of new challenges were found.

  • 6.
    Ayaad, Abed-e
    University West, Department of Engineering Science, Division of Automation Systems.
    AGV solution in production lines2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project describes and discusses the technical issues and the benefits of using the auto-mated guided vehicles (AGVs) solution in production lines to take care of materials handling system in order to increase the flexibility and productivity of a manufacturing system.

    This work started with literature study on AGVs in general and gathering information about existing technologies from the previous and ongoing researches. This gathered knowledge has been used as a base to the practical work. The main aim of the practical work is to implement an AGV in the production line at PTC at University West. In order to per-form the implementation a guidance loop of magnetic tape has been designed. To achieve the goal of this work several tests and experiments have been done to evaluate the validation of the modeled AGV system.

  • 7.
    Batungwanayo, Guillaume
    University West, Department of Engineering Science, Division of Automation Systems.
    Weld bead tracking by use of an infra-red vision system2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A survey of robotized seam-tracking techniques was conducted in preparation for a project consisting of using an infrared camera on a robot for on one side collect continuous weld images for NDT inspection and on the other one track the weld joint. The tracking system can be used to discover the position of the weld bead without previous information. The robust system is outlined, along with its merits and disadvantages.

  • 8. Batungwanayo, Guillaume
    et al.
    Runnemalm, Anna
    University West, Department of Engineering Science, Division of Automation Systems.
    Ericsson, Mikael
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Weld Joint Tracking System in an Automatic Inspection Cell by Using Emissivity Variation2014In: Proceedings of the 6th International Swedish Production Symposium 2014 / [ed] Stahre, Johan, Johansson, Björn & Björkman, Mats, 2014, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Thermography has proven to be a suitable nondestructive testing method for automatic crack inspection of welds. However automatic weld inspection raises challenges. E.g. the position of the weld might not be exactly as the predefined weld seam, and a weld joint tracking system is needed. To reduce the number of equipment used, a solution is presented in this papers. The infrared camera in the thermography system is a carrier of information of the weld path. This is used for the weld joint tracking system. It is shown that the weld joint tracker is fast enough for an on-line automatic inspection.

  • 9.
    Benages Montolío, Sergio
    University West, Department of Engineering Science, Division of Automation Systems.
    Robot Behaviour Monitoring in Friction Stir Welding2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Friction Stir Welding is a solid state join process in which the heat need is produced by the friction of a tool on the work pieces. The tool rotates on the surface and also applies a force against it to create the needed friction. This technology does not use any consumable and does not produce any gas, which makes it cost effective, save for the operators and clean.

    The equipment used for this technology has been changing within the years. Milling machines were adapted to it at the beginning. After, specific machines for friction stir welding were developed, providing higher down force and control systems. Nevertheless, the lack of flexibility of machines made industrial robots became an alternative. Robots have limitations in terms of stiffness. But, they can be used to weld complex geometries and they can be used in large scale applications due to their flexibility and low cost.

    This project studies the process from the robot behaviour perspective. The main objective is to achieve a better understanding of the process to contribute to the continuous development of robotic FSW. An acquisition system was developed to monitor different signals from the robot such as, forces, torque, path deviation, and vibrations. The data acquisition system developed and mounted at PTC was tested and its limitations were examined. The developed system has been used for conducting different experiments: The differences between the robot system and a system based on a FSW machine situated at TWI were studied; and, in addition, the behaviour of the robot under different welding parameters was investigated.

  • 10.
    Bengtsson, Karl-Johan
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Frändén, Johan
    University West, Department of Engineering Science, Division of Automation Systems.
    Jämförelse av hjälpkraftssystem för HVDC-stationer2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is about two different HVDC (High Voltage Direct Current) connections in the North Sea. They are called DolWin1 and DolWin2, both of them are designed by ABB. This essay will with the help of ABB's documentation describe the low voltage switchgear (LVS) of the HVDC converter stations, compare the different solutions and present the advantages and disadvantages of the systems. The low voltage switchgear is a part of the auxiliary power systems of the stations. The purpose of the auxiliary power system is to deliver electrical power to breakers, cooling systems, ventilation and other loads necessary to keep the converter stations functional.

    DolWin1 was the first connection of the two to be constructed and it was completed in 2014. DolWin1 was designed by ABB Sweden and DolWin2 was designed by ABB in Germany. DolWin2 has a bit more capacity and the connection is not yet fully completed. [1]

    ABB, Transformer handbook, Zürich: ABB, 2004.

    [2]

    C. Gunnarsson, "The history of HVDC transmission," Okänt år. [Online]. Available: http://www04.abb.com/global/seitp/seitp202.nsf/0/a521beb28ac88e75c12572250046e16a/$file/hvdc+history.pdf. [Använd 17 April 2014].

    [3]

    ABB, "Introducing HVDC," Okänt datum 2014. [Online]. Available: http://www05.abb.com/global/scot/scot221.nsf/veritydisplay/8c9e9057be8603f2c1257c6200413e48/$file/POW0078_LR.pdf. [Använd 17 April 2014].

    [4]

    B. Stenborg, "högspänd likström," NE, Okänt år. [Online]. Available: http://www.ne.se.ezproxy.server.hv.se/lang/h%C3%B6gsp%C3%A4nd-likstr%C3%B6m?i_h_word=hvdc. [Använd 17 April 2014].

    [5]

    G. Elfving, ABB handbok elkraft, Västerås: ABB, 1989.

    [6]

    ABB Communications, "ABB installs world's most powerful offshore HVDC converter station," ABB, 26 Augusti 2013. [Online]. Available: http://www.abb.com/cawp/seitp202/e6c88e4323510393c1257bd3002bee38.aspx. [Använd 5 Maj 2014].

    [7]

    V. S, "Single Line Diagram DolWin1, 800 MW Dörpen West Converter Station," ABB AB, okänd ort, 2014.

    [8]

    Furberg Mattias H, "Station Service Power," ABB, okänd, 2014.

  • 11.
    Bennulf, Mattias
    University West, Department of Engineering Science, Division of Automation Systems.
    Mobile robot navigation and control: Applied on PatrolBot2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    University west have a production line where a mobile robot could be used in the future for education or research. The production line uses multiple PLCs for control of industrial robots and other machines. To be able to use the mobile robot system it is necessary to have some kind of communication between the mobile robot system and the existing communication in the production line. This project solves this by using the standardized Modbus protocol to connect a PLC to a server running Debian Linux that controls all ro-bots. All additional programming is supposed to be done in the PLC when this system is used. This is because of the frequent use of PLC in industries and ease of debugging. The communication between the PLC and server is setting register values through Modbus for moving robots to targets and getting info from server to PLC. In this project an HMI is created that is a control panel for the mobile robot system. The HMI is created with a fo-cus on being easy to use and quick to learn. A typical application in an industrial environment for mobile robots is to move items between different robot cells. The problem is that a regular industrial robot might need the mobile robot to be within a few millimetres precision to be able to grasp the item and move it, depending on the tool used. This project measured the accuracy of going to targets with the PatrolBot robot. This showed that the robot might need a complementary system like vision for localizing the robot at the loading and unloading stations if moving items between different robot cells.

  • 12.
    Berntsson, Andreas
    University West, Department of Engineering Science, Division of Automation Systems.
    Kartläggning av kvalitetsrisker vid mellanlagring, Akzo Nobel, Surface Chemistry, Stenungsund2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor's thesis was carried out at Akzo Nobel Surface Chemistry in Stenungsund the winter of 2015 and deals with quality risks related to intermediate storage of products before they are tapped for delivery to customer. The thesis is limited to pipelines from the production process to a tank storage area called Östra tankdäck containing 25 storage tanks. A performed analysis of all quality deviations the last three years showed that it was interesting to examine the quality risk at Östra tankdäck. The aim of this thesis was to gain better understanding of the quality risks so appropriate actions could be taken to keep the products within customer specifications.

    Since there is more products than storage tanks sequencing is performed in pipelines and storage tanks between products. The sensitivity between the products varies and if too big admixtures occur between the wrong products, quality deviations follow. The deviations leads to extra work and, at worst, the products cannot be used and must be burned.

    Quality risks in the pipelines were quantified based on previous tests, for example where one meter horizontal pipe is estimated to contain x liters of products after cleaning is performed. This was followed by a mapping of the whole pipeline system. Based on the mapping a diagnostic program was designed that calculated mixing quantities in product sequencing. An attempt to quantify the quality risk in the storage tanks was made by comparing the water level before and after pumping to the storage tank. The measurement system variation was judged too high to allow any conclusion from the analysis and recommendations to control the measurement system were made. Furthermore, the most appropriate method to quantify the risk was considered to be internal inspections.

    One conclusion is that the quality risks in the pipelines are too complex to be evaluated manually without quality deviations eventually occurring. To ensure product quality a computer-based aid must be used. Another conclusion is that the quality risk in the storage tank would be eliminated and in the pipelines reduced if loading was made directly into a tank container.

  • 13.
    Berntsson, Caroline
    University West, Department of Engineering Science, Division of Automation Systems.
    Reduce Lead Time in Sales Process;: a study of streamlining business process and improve interaction between critical sub processes at Valmet AB/Energy2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis aimed to generate improvement proposals to reduce lead time in the sales process. The parameter to identify was how the lead time was affected of variation, waste and constraints within the process. Furthermore, the interaction between including subprocesses and the internal customer requirements on the sales process were also part of the scope.

    To achieve the objectives a current situation analysis was performed. The analysis generated information about the included activities that the sales process holds. Findings from the analysis were that the total amount of time required for the sales process was large in comparison to the customer required lead time due to efficient islands within the process. One area of improvement was the information flow and communication during the pre-project. Activities like gathering information, review information and waiting for other functions were consequences of insufficient information flow and interactions between subprocesses. Furthermore, due to parallel working activities performed by the functions the average available time per day to handling inquiries is limited. This together with variation caused by inquiries that passing the line generates overloaded resources which influence the overall lead time and decrease the efficiency.

    To reduce bottlenecks, variation and wastes caused by insufficient information the improvement proposals included to; perform a preliminary study; identifying the information needed from the start-up meetings in a communication plan and; establish visual management in combination with daily scrum. The benefits of the improvement proposal are reduced lead time and increased interaction between included subprocesses. Further the improvement proposals will also provide preconditions for single piece flow and flow efficiency.

  • 14.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation Systems.
    Supporting Tools for Operator in Robot Collaborative Mode2015In: Procedia Manufacturing, ISSN 2351-9789, Vol. 3, p. 409-416Article in journal (Refereed)
    Abstract [en]

    Making use of robot automation for customized products put high demand not only on the robot but on the efficiency, simplicity and flexibility to actually deploy and use robots in manufacturing stations and production lines in short batches and low volume production. Hence, market oriented product development and production requires more products to be developed and offered in less time than before, and produced for the market with more customizable options. The role of the operator is in this context an important factor and tools are needed to support the operator for highly efficient and flexible production. In this paper, the development and study of supporting tools for operators is presented. A demonstrator has been built for robotic nailing, screwing and manipulation operation in producing scaled down gable wall elements in wood for a family house. Issues raised to support the operator included automatic programming and generating relevant information for the operator for the deployment procedure to prepare for production. During production, different concepts of safety system to support collaboration mode between the operator and the robot was developed and studied. Wearable devices was used for the operator to access the information generated and different safety configurations were developed and evaluated. The baseline for this work has been to identify industrial use cases which has a clear need for automation as well as collaboration between operator(s) and robot(s). Work scenarios were discussed and analyzed with industrial partners and it was concluded that, in addition to the deployment tools, a smart safety system which is able to detect and react on humans entering the robot system work area is needed. This should support for efficient production and less downtime for both automatic mode and collaboration mode. The benefit of operator – robot collaboration is clearly shown as well as the need for supporting tools.

  • 15.
    Bring, Hampus
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Emanuelsson, Olle
    University West, Department of Engineering Science, Division of Automation Systems.
    Vinkelfelet i mätkretsens påverkan på riktade jordfelsskydd2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor's thesis examines the angular error in the measurement circuit for directional earth-fault protection and how this error affects the fault disconnection. Angular errors in the measurement circuit can affect the directional earth-fault protection in such a way that the real fault current and the measured fault current do not match. This can lead to missed or unwarranted fault disconnections. Vattenfall has a requirement which states that the angular error must not exceed ±2 degrees for the measurement circuit. Since the angular error in many cases has a high impact on the earth-fault accuracy, an investigation concerning what Vattenfalls angle requirement really means. The main cause of the angular error usually occurs in the current transformers and therefore two commonly used current transformers in the grid with different classifications and their impact on the angular error in the measurement circuit are examined.

    Ground fault is the most common fault which occurs in a distribution network, its size depends largely on the amount of capacitive current which the grid contributes with as well as the size of the neutral grounding resistor. The capacitive contribution of the grid compensates centrally in the distribution station and sometimes locally on the line. The maximum permitted centrally compensated part of a line is limited to 30 A, this central part can go up to 60 A in case the line needs to be fed from a second distribution station. The angular error has a higher impact if the capacitive contribution is high and for low values of the neutral grounding resistor. In many cases more than one earth-fault protection are found on the same line, in these cases selectivity is always pursued. The angular error may have a negative effect on the selectivity.

    By calculations, simulations and tests a number of conclusions can be drawn. Vattenfalls

    angle requirement gives an unclear picture concerning the permitted impact on the earthfault

    protection. Moreover selecting the correct current transformer demonstrates that the

    angular requirement can probably be sharpened. To reduce the influence of the angular error

    the maximum permitted centrally compensated part be reduced and/or the value of the

    neutral grounding resistor can be increased. A selectivity of 1000

    Ω can not always be applied

    since certain cases require a selectivity of 2000

    Ω. By setting the zero sequence voltage as the

    trigger condition and the zero sequence current as the realese condition, according to this

    study it may be possible to achieve a more accurate earth-fault protection.

  • 16.
    Broberg, Patrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Analysis method for pulsed thermography based on an analytical solution of the heat equation2014Article in journal (Refereed)
    Abstract [en]

    An analytical solution to the heat equation is presented, using a simplified physical model of pulsed thermography. This solution was compared to experimental data and showed good correlation, with r=0.97. An analysis method for sizing and determining the depth of a defect was developed using this analytical solution. The shape of the defect was estimated using deconvolution. Results from thermography tests on flat bottom holes show the possibilities of the method to determine the size, shape and depth of the defect, if the physical properties of the material are known.

  • 17.
    Broberg, Patrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Analytic model for pulsed thermography of subsurface defects2014In: Archives QIRT 2014: Documents and sessions presented during the 12nd conference QIRT (Bordeaux, France), QIRT , 2014, p. 1-5Conference paper (Refereed)
    Abstract [en]

    An analytic solution to the heat equation is used to model the response of subsurface defects in pulsed thermography. The model is compared to measurement data and shows good agreement, both in spatial and temporaldomain. The capability of the model is then demonstrated by calculating the response of arbitrary defects at different depth. This model, even though simplified, can prove useful due to good accuracy and low computational time forcomparing analysis methods and for evaluating a thermography method on a new material or new type of defect.

  • 18.
    Broberg, Patrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Imaging and analysis methods for automated weld inspection2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    All welding processes can give rise to defects, which weakens the joint and can eventually lead to the failure of the welded structure. In order to inspect welds for detects, without affecting the usability of the product, non-destructive testing (NDT) is needed. NDT includes a wide range of different techniques, based on different physical principles, each with its advantages and disadvantages. The testing is often performed manually by a skilled operator and in many cases only as spot-checks. Today the trend in industry is to move towards thinner material, in order to save weight for cost and for environmental reasons. The need for inspection of a larger portion of welds therefore increases and there is an increasing demand for fully automated inspection, including both the mechanised testing and the automatic analysis of the result. Compared to manual inspection, an automated solution has advantages when it comes to speed, cost and reliability. A comparison of several NDT methods was therefore first performed in order to determine which methods have most potential for automated weld inspection. Automated analysis of NDT data poses several difficulties compared to manual data evaluation. It is often possible for an operator to detect defects even in noisy data, through experience and knowledge about the part being tested. Automatic analysis algorithms on the other hand suffer greatly from both random noise as well as indications that originate from geometrical variations. The solution to this problem is not always obvious. Some NDT techniques might not be suitable for automated inspection and will have to be replaced by other, better adapted methods. One such method that has been developed during this work is thermography for the detection of surface cracks. This technique offers several advantages, in terms of automation, compared to existing methods. Some techniques on the other hand cannot be easily replaced. Here the focus is instead to prepare the data for automated analysis, using various pre-processing algorithms, in order to reduce noise and remove indications from sources other than defects. One such method is ultrasonic testing, which has a good ability for detecting internal defects but suffers from noisy signals with low spatial resolution. Work was here done in order to separate indications from corners from other indications. This can also help to improve positioning of the data and thereby classification of defects. The problem of low resolution was handled by using a deconvolution algorithm in order to reduce the effect of the spread of the beam.The next step in an automated analysis system is to go beyond just detection and start characterising defects. Using knowledge of the physical principles behind the NDT method in question and how the properties of a defect affect the measurement, it is sometimes possible to develop methods for determining properties such as the size and shape of a defect. This kind of characterisation of a defect is often difficult to do in the raw data, and is therefore an area where automated analysis can go beyond what is possible for an operator during manual inspection. This was shown for flash thermography, where an analysis method was developed that could determine the size, shape and depth of a defect. Similarly for laser ultrasound, a method was developed for determining the size of a defect.

  • 19.
    Broberg, Patrik
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Garner, Simon
    TWI.
    Sizing of subsurface defects in thin walls using laser ultrasonics2014Article in journal (Refereed)
    Abstract [en]

    Laser ultrasonics is a non-destructive testing technique where a focused laser is used for generating an ultrasound pulse and a second laser is used for detection. This ultrasound pulse is used for detecting surface or near surface defects. A defect will not only reflect the incoming surface wave, but also alter the frequency contents of the transmitted wave. When the detection laser was scanned along the surface, changes in frequency contents of the sound pulse were detected and could be analysed to give information about the diameter of the defect.

  • 20.
    Claesson, Niclas
    University West, Department of Engineering Science, Division of Automation Systems.
    Modernisering av montageanvisningar för utomhusställverk 40-400kV2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Since the construction of the main and regional power line networks in Sweden during the 1940-80s, the power lines and the outdoor switchgear have just been undergoing general management during this time. In the middle of the first decade in the 21 century, demand for the construction of new power lines and outdoor switchgear took place. This was mainly due to increased power consumption from customers and that society have become more energy intensive.

    This thesis deals with general operating instructions as to how the procedure for lifting steel and apparatus are done and how these are to be fixed in an outdoor switchgear. The thesis is also dealing with how to install power lines, mount clamps and conductors for apparatus. The work also focuses on procedures how to receive goods, self inspection of these and how to store them. The thesis also contains what safety equipment and tools might be needed for the job.

    The methods for how to build outdoor switchgear today and back in the days are mainly the same. Today you have more advanced tools like lasers which helps you measure distances more easily and is reducing the number of measures needed. With mobile work platforms and 4-wheelers today you can be more mobile than back in the days when you only had tractors and mobile cranes.

    With good planning and the use of risk analysis methods like FMEA "Failure Modes and Effects Analysis" before starting a work, you can minimize the work casualties and accidents dramatically. With FMEA you can evaluate the risks and prevent them before they happen. With standardized work and instructions you minimize work casualties and accidents since you have instructions to follow and would not risk to miss any important stage of the work that will cause injury or casualty. This will increase the safety and quality of the work. Toyotas principles can be used in most professions and not just the car industry. With more companies using standardized work you will increase safety and quality of work which will decrease the number of casualties and accidents for the people working.

  • 21.
    Danielsson, Fredrik
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Reddy, Dhanush
    University West, Department of Engineering Science, Division of Automation Systems.
    A genetic algorithm with shuffle for job shop scheduling problems2015In: Modelling and simulation 2015: The European simulation and modelling conference 2015, ESM 2015, October 26-28 Leicester, United Kingdom / [ed] Marwan Al-Akaidi & Aladdin Ayesh, Ostend: ESM , 2015, p. 363-367Conference paper (Refereed)
    Abstract [en]

    Job shop scheduling problems are computationally complex combinatorial optimization problems. Genetic algorithms have been used in various forms and in combination with other algorithms to solve job shop scheduling problems. A partially flexible job shop with precedence constraints increases this complex behaviour. There are two main parts to optimizing ajob shop, the routing and the scheduling. The objective here is to get consistent optimal makespan using a genetic algorithm. This paper firstly, presents a simulation approach for the considered partially flexible job shop scheduling problem. Which take into account the precedence constraints and reduce situations of deadlock. To solve the partially flexible job shop scheduling problem a genetic algorithm was used and improved. It utilise a genetic crossovers for routing and a new random shuffle feature is introduced for the scheduling. The computational results have shown that the algorithm performs well in terms of finding a consistent optimal schedule for the given problem

  • 22.
    De Backer, Jeroen
    University West, Department of Engineering Science, Division of Automation Systems.
    Feedback Control of Robotic Friction Stir Welding2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The Friction Stir Welding (FSW) process has been under constant developmentsince its invention, more than 20 years ago. Whereas most industrial applicationsuse a gantry machine to weld linear joints, there are applications which consistof complex three-dimensional joints, requiring more degrees of freedom fromthe machines. The use of industrial robots allows FSW of materials alongcomplex joint lines. There is however one major drawback when using robotsfor FSW: the robot compliance. This results in vibrations and insufficient pathaccuracy. For FSW, path accuracy is important as it can cause the welding toolto miss the joint line and thereby cause welding defects.The first part of this research is focused on understanding how welding forcesaffect the FSW robot accuracy. This was first studied by measuring pathdeviation post-welded and later by using a computer vision system and laserdistance sensor to measure deviations online. Based on that knowledge, a robotdeflection model has been developed. The model is able to estimate thedeviation of the tool from the programmed path during welding, based on thelocation and measured tool forces. This model can be used for online pathcompensation, improving path accuracy and reducing welding defects.A second challenge related to robotic FSW on complex geometries is thevariable heat dissipation in the workpiece, causing great variations in the weldingtemperature. Especially for force-controlled robots, this can lead to severewelding defects, fixture- and machine damage when the material overheats.First, a new temperature method was developed which measures thetemperature at the interface of the tool and the workpiece, based on the thermoelectriceffect. The temperature information is used as input to a closed-looptemperature controller. This modifies primarily the rotational speed of the tooland secondarily the axial force. The controller is able to maintain a stablewelding temperature and thereby improve the weld quality and allow joining ofgeometries which were impossible to weld without temperature control.Implementation of the deflection model and temperature controller are twoimportant additions to a FSW system, improving the process robustness,reducing the risk of welding defects and allowing FSW of parts with highlyvarying heat dissipation.

  • 23.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation Systems.
    Surface Quality and Strength in Robotic Friction Stir Welding of Thin Automotive Aluminium Alloys2011In: The 4th International Swedish Production Symposium / [ed] Jan-Eric Ståhl, The Swedish Production Academy , 2011, p. 554-562Conference paper (Refereed)
    Abstract [en]

    Friction Stir Welding (FSW) is a novel method for joining materials without using consumablesand without melting the materials. It uses a rotating tool that creates frictionalheat and mixes the materials mechanically together. Robotic application of FSW allowsthree-dimensional welding of light-weight metals in e.g. the automotive industry. TheStiRoLight project is driven by Saab Automobile AB and performed at University Westfor investigation of robotic FSW of three-dimensional welding seams. It aims to introduceFSW in the automotive production line. This paper describes the effect of penetrationdepth of the FSW tool during force controlled robotic welding of thin (< 2 mm) aluminium inoverlap configuration. The influence of pin length on strength of welded aluminium sheetsis investigated using tensile and peel tests. The main limiting factor for penetration depthis the surface quality on the backside of the weld, which often is important in automotiveapplications. Further, the roughness of the plates on the backside is measured and relatedto pin length and backing bar properties. This paper shows a relation between penetrationdepth and tensile strength, and suggests an optimal pin length to guarantee a good weldquality while maintaining an acceptable surface quality. The influence of sheet thicknesstolerance is also discussed. Knowledge is fed back to designers and manufacturingengineers to facilitate for use in production with guaranteed product quality.

  • 24.
    Dirki, Lawand
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Kecevic, Amer
    University West, Department of Engineering Science, Division of Automation Systems.
    Utvärdering av nya material för jordningar2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report aims to provide a basis for Vattenfall Eldistribution AB, for any eventual decision making regarding alternative grounding materials that can replace the copper wire. Copper wire is today used for grounding because of its quality, but the high scrap value of copper has made the material theft-prone and characterized companies with costly repairs.

    Some parts of Västra Götaland, where copper wire is used, are seriously affected by thefts. To try to reduce the damage of the thefts, Vattenfall has begun to test replacing the copper wire with Copperweld® (CCS) on their utility poles.

    Copperweld® (CCS) is a copper clad steel wire of much lower scrap value. The material has similar properties as copper wire and can be used as a ground conductor because it fulfills the conductivity requirements of a material, set by Svensk Standard.

    Copperweld® (CCS) should be able to resist corrosion for at least 40 years compared to the copper wire, which in many cases has an unnecessarily long life span. There is no big difference between the purchase price of the Copperweld® (CCS) and the copper wire, and the installation principle is also identical. Based on this evolution, if Vattenfall decide to change copper wire to Copperweld® (CCS), they will save between 10-39 million SEK annually in repair

    expenditures.

  • 25.
    Eliasson, Peter
    University West, Department of Engineering Science, Division of Automation Systems.
    Elenergibesparande åtgärder för ett flerbostadshus i Säffle2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this work was to find energysaving arrangements for an apartment block situated in Säffle. The energysaving comprises lightning and appliances. The apartment block has an electricity consumption of 9 189 kWh/year which covers applianceroom, lightning indoors and lightning outdoors. Because of confidentiality the calculations are based on a fully occupied apartment block, therefor total annual saving will exceed current electricity consumption. Improvement measures for applianceroom is to change the drycleaner,

    Miele t5213, to drycleaner Electrolux T4300 LE. The drying cabinets Elektro Helios TK 7022 and ASKO nimo ETS 1900 are changed to two Cylinda TS 190VP ECO drying cabinets. These measures give an energysaving of 9 255 kWh/year calculated on a fully preoccupied apartment block and that all resident use the laundry.

    For indoor lightning the 58 W T8 strip lights are changed to 35 W T5 and 22 W T8 strip lights are changed to 13 W T5. The measure give an annual energysaving of 2 137 kWh. For outdoor lightning the 125 W mercury lights are changed to 60 W LED-lamps and the 125 W halogen lamps are changed to 40 W LED-lamps. The measure give an annual energysaving of 2 060 kWh. Total saving becomes 14 492 kWh/year which corresponds to 52 % lower energy consumption. Total investment is estimated to 75 000 sek (material 50 000 sek and work 25 000 sek) and the repayment period is calculated to 7,5 years. The result is a hint of what energysavings that can be achieved. Manual steering of the lightning should be changed into presencesensor and can be complemented with a foglightsystem. These measures are not included in the calculation of the total annual energysaving.

  • 26.
    Ellers, Fredrik
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Knutsson, Stefan
    University West, Department of Engineering Science, Division of Automation Systems.
    Utveckling, konstruktion och CE-märkning av robotcell för utbildningssyfte2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis work has focused on the efforts to CE-mark a robot cell that has been developed by us to be used for educational purposes. A significant part of the thesis work was to gather the necessary information regarding the CE-marking, robot safety and risk assessments. Security measures have been taken to achieve the requirements concerning the standards, and the conditions concerning both the limited surface and the environment the robot cell is to be used in. This thesis work has developed a large amount of technical documentation. This will be the basis for the final CE-marking of the robot cell. The CE-marking is not completed because the robot cell is not fully developed yet. This leads to that the CE marking cannot be completed until the final tests have been performed on the completed cell, regarding the construction and safety integrity of the structure

  • 27.
    Ericsson, Mikael
    et al.
    University West, Department of Technology, Mathematics and Computer Science, Division for Mechanical Engineering.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation Systems.
    Nylén, Per
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Three-dimensional simulation of robot path and heat transfer of a TIG-welded part with complex geometry2002In: 11th International Conferences on Computer Technology in Welding: Colombus, Ohio December 6-7, 2001, 2002, p. 309-316Conference paper (Other academic)
    Abstract [en]

    The application of commercial software (OLP) packages for robot simulation, and programming, use interactive computer graphics, provide powerful tools for creating welding paths off-line. By the use of such software, problems of robot reach, accessibility, collision and timing can be eliminated during the planning stage. This paper describes how such software can be integrated with a numerical model that predicts temperature-time histories in the solid material. The objective of this integration is to develop a tool for the engineer where robot trajectories and process parameters can be optimized on parts with complex geometry. Such a tool would decrease the number of weld trials, increase productivity and reduce costs. Assumptions and principles behind the modeling techniques are presented together with experimental evaluation of the correlation between modeled and measured temperatures.

  • 28.
    Ericsson, Mikael
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Ryberg, Anders
    Nilsson, Jim
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    Chalmers.
    Off-Line Simulation of Advanced Stereo Vision Welding Applications2010In: Machine Vision and Applications, ISSN 0932-8092, E-ISSN 1432-1769Article in journal (Refereed)
  • 29.
    Eriksson, Carl
    University West, Department of Engineering Science, Division of Automation Systems.
    Evaluating a method for finding the bottleneck in a production flow2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report will reveal the results of bachelor thesis project at Innovatum AB in Trollhättan, Sweden. The project is a continuation on earlier projects done in the same field of study. It all started when scientists at Innovatum AB conducted a research about the theory of easily finding bottlenecks in a manufacturing production. This would be done without using mathematical calculations or time measurements but simply by observing and walking along the production flow.

    The purpose of the study was to evaluate this bottleneck theory by using it in practice and analysing the results.

    The result and conclusion of the study shows that the method is useful for simple bottleneck detection. One prerequisite is that the inventory levels are clearly visible. The method works moreover better when the inventories are not used as a repositories for a longer period of time.

  • 30.
    Fuente, Raquel
    et al.
    IK4-LORTEK, Ordizia, Spain.
    García de la Yedra, Aitor
    IK4-LORTEK, Ordizia, Spain.
    Beizama, Ane Miren
    IK4-LORTEK, Ordizia, Spain.
    Fernández, Erik
    IK4-LORTEK, Ordizia, Spain.
    Gorostegui Colinas, Eider
    IK4-LORTEK, Ordizia, Spain.
    Echeverria, Alberto
    IK4-LORTEK, Ordizia, Spain.
    Broberg, Patrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Thorpe, Nigel
    Tecnitest ingenieros, Madrid, Spain.
    Runnemalm, Anna
    University West, Department of Engineering Science, Division of Automation Systems.
    Henrikson, Per
    GKN Aerospace Engine Systems Sweden, Trollhättan, Sweden.
    Development and demonstration of an automated system for limited access weld inspection by using infrared active thermography2015In: Proceedings 7th International Symposium on NDT in Aerospace, Berlin, 2015, p. 1-8Conference paper (Refereed)
    Abstract [en]

    Weld inspection for surface breaking defects detection has been traditionally performed by using NDT methods such as Fluorescent PenetrantInspection (FPI), Visual Inspection (VI) or Eddy Currents (EC). All those well known techniques have as common drawback the need of skilled operator intervention in order to analyse obtained results. In the specific case of inspection of welds with limited access, the application of those traditional methods is even more complex, thus increasing inspection time and reducing the defect detection capability. Therefore, the development of a fully automated non-contact method overcoming these limitations is desired. Active thermography (IRT) represents one of the most promising techniques for replacing traditional techniques for surface breaking defect detection in welds.This technique makes use of an excitation source in order to heat the sample undertest and an infrared camera for thermal evolution monitoring. With the combination of these excitation-monitoring techniques, heterogeneities in the heat flow caused bysurface breaking cracks can be detected. In this work, a robotic solution was developed and demonstrated for the inspection of welds with real cracks in a representative environment with limited access. The system consists of a continuous laser-line excitation source together with a FLIR SC 655 micro bolometer thermographic camera. In order to access limited areas, two different aluminium polished mirrors have been used for bothinfrared radiation monitoring and laser excitation respectively. The inspection results, analysis and comparison with traditional methods will be shown.

  • 31.
    Garcia de la Yedra, Aitor
    et al.
    Control and Evaluation, IK4-LORTEK; Arranomendia Kalea 4A, Ordizia, Spain.
    Fernandez, Erik
    Control and Evaluation, IK4-LORTEK; Arranomendia Kalea 4A, Ordizia, Spain.
    Beizama, Ane Miren
    Control and Evaluation, IK4-LORTEK; Arranomendia Kalea 4A, Ordizia, Spain.
    Fuente, R.
    Control and Evaluation, IK4-LORTEK; Arranomendia Kalea 4A, Ordizia, Spain.
    Echeverria, A.
    Control and Evaluation, IK4-LORTEK; Arranomendia Kalea 4A, Ordizia, Spain.
    Broberg, Patrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Runnemalm, Anna
    University West, Department of Engineering Science, Division of Automation Systems.
    Henrikson, Per
    GKN Aerospace Engine Systems.
    Defect strategies in Nickel Superalloys weld using active thermography2014In: 12th International Conference on Quantitative InfraRed Thermography, 7-11/7 Bordeaux, 2014, p. 1-9Conference paper (Refereed)
    Abstract [en]

    As a result of extreme operation conditions in gas turbines, high resistance materials with excellent behaviour at high temperature are required. Alloys, such as MarM-247 nickel based superalloy, with excellent mechanical properties at very high temperature (even at 85 % of their melting point) are being used in these applications. This extraordinary behaviour is mainly due to the presence of a strengthening phase (γ’) with the following chemical composition: Ni3(Al, Ti). However, during welding these materials are susceptible to cracking and this is why weld inspections become crucial. In this work different strategies for defect detection in welds are introduced, all of them based on active thermography. The work covers aspects such as different excitation and data evaluation strategies.

  • 32.
    Glorieux, Emile
    University West, Department of Engineering Science, Division of Automation Systems.
    Constructive cooperative coevolution for optimising interacting production stations2015Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Engineering problems have characteristics such as a large number of variables, non-linear, computationally expensive, complex and black-box (i.e. unknown internal structure). These characteristics prompt difficulties for existing optimisation techniques. A consequence of this is that the required optimisation time rapidly increases beyond what is practical. There is a needfor dedicated techniques to exploit the power of mathematical optimisation tosolve engineering problems. The objective of this thesis is to investigate thisneed within the field of automation, specifically for control optimisation ofautomated systems.The thesis proposes an optimisation algorithm for optimising the controlof automated interacting production stations (i.e. independent stations thatinteract by for example material handling robots). The objective of the optimisation is to increase the production rate of such systems. The non-separable nature of these problems due to the interactions, makes them hard to optimise.The proposed algorithm is called the Constructive Cooperative CoevolutionAlgorithm (C3). The thesis presents the experimental evaluation of C3, bothon theoretical and real-world problems. For the theoretical problems, C3 istested on a set of standard benchmark functions. The performance, robustness and convergence speed of C3 is compared with the algorithms. This shows that C3 is a competitive optimisation algorithm for large-scale non-separable problems.C3 is also evaluated on real-world industrial problems, concerning thecontrol of interacting production stations, and compared with other optimisation algorithms on these problems. This shows that C3 is very well-suited for these problems. The importance of considering the energy consumption and equipment wear, next to the production rate, in the objective function is also investigated. This shows that it is crucial that these are considered to optimise the overall performance of interacting production stations.

  • 33.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Automation Systems. Chalmers University of Technology, Department of Signals and Systems, Gothenburg, Sweden.
    Constructive cooperative coevolutionary optimisation for interacting production stations2015In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 78, no 1-4, p. 673-688Article in journal (Refereed)
    Abstract [en]

    Optimisation of the control function for multiple automated interacting production stations is a complex problem, even for skilled and experienced operators or process planners. When using mathematical optimisation techniques, it often becomes necessary to use simulation models to represent the problem because of the high complexity (i.e. simulation-based optimisation). Standard optimisation techniques are likely to either exceed the practical time frame or under-perform compared to the manual tuning by the operators or process planners. This paper presents the Constructive cooperative coevolutionary (C3) algorithm, which objective is to enable effective simulation-based optimisation for the control of automated interacting production stations within a practical time frame. C3 is inspired by an existing cooperative coevolutionary algorithm. Thereby, it embeds an algorithm that optimises subproblems separately. C3 also incorporates a novel constructive heuristic to find good initial solutions and thereby expedite the optimisation. In this work, two industrial optimisation problems, involving interaction production stations, with different sizes are used to evaluate C3. The results illustrate that with C3, it is possible to optimise these problems within a practical time frame and obtain a better solution compared to manual tuning.

  • 34.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Lennartson, Bengt
    Chalmers University of Technology, Department of Signals and Systems.
    Optimisation of Interacting Production Stations using a Constructive Cooperative Coevolutionary Approach2014In: Proceedings of 2014 IEEE International Conference on Automation Science and Engineering (CASE), IEEE conference proceedings, 2014, p. 322-327Conference paper (Refereed)
    Abstract [en]

    Simulation-based optimisation carries the burden of computationally expensive fitness calculations. It is very often used to tackle large-scale optimisation problems with a relatively high level of complexity. Therefore, it is of interest to have optimisation techniques dedicated to simulation-based optimisation. This paper proposes a simulation-based optimisation approach, called Constructive Cooperative Coevolutionary (C3) search procedure, to optimise the control of interacting production stations. An optimisation algorithm is embedded in the C3 search procedure to optimise subproblems separately. It includes a novel constructive heuristic that creates a feasible solution for the considered problem efficiently. It also incorporates an extended version of the existing cooperative coevolutionary method that can handle large-scale optimisation problems. Furthermore, this paper presents a case study considering a sheet metal press line as an example of interacting production stations. In this case study, the performance of the proposedC3 search procedure is evaluated and compared with other optimisation algorithms. This shows that the C3 search procedure is able to successfully optimise the press line within a given number of fitness calculations, outperforming existing algorithms. Also, it is shown that C3 can be embedded with either stochastic or deterministic optimisation algorithms, without sacrificing performance.

  • 35.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    University West, Department of Technology, Mathematics and Computer Science, Division for Electrical Engineering and Land Surveying. Department of Signals and Systems, Chalmers University of Technology, Gothenburg, Sweden.
    A Constructive Cooperative Coevolutionary Algorithm Applied to Press Line Optimisation2014In: Proceedings of the 24th International Conference on Flexible Automation and Intelligent Manufacturing: Capturing Competitive Advantage via Advanced Manufacturing and Enterprise Transformation / [ed] F. Frank Chen, Lancaster, PA, USA: DEStech Publications, Inc. , 2014, p. 909-916Conference paper (Refereed)
    Abstract [en]

    Simulation-based optimisation often considers computationally expensive problems. Successfully optimising such large scale and complex problems within a practical time frame is a challenging task. Optimisation techniques to fulfil this need to be developed. A technique to address this involves decomposing the considered problem into smaller subproblems. These subproblems are then optimised separately. In this paper, an efficient algorithm for simulation-based optimisation is proposed. The proposed algorithm extends the cooperative coevolutionary algorithm, which optimises subproblems separately. To optimise the subproblems, the proposed algorithm enables using a deterministic algorithm, next to stochastic genetic algorithms, getting the flexibility of using either type. It also includes a constructive heuristic that creates good initial feasible solutions to reduce the number of fitness calculations. The extension enables solving complex, computationally expensive problems efficiently. The proposed algorithm has been applied on automated sheet metal press lines from the automotive industry. This is a highly complex optimisation problem due to its non-linearity and high dimensionality. The optimisation problem is to find control parameters that maximises the line’s production rate. These control parameters determine velocities, time constants, and cam values for critical interactions between components. A simulation model is used for the fitness calculation during the optimisation. The results show that the proposed algorithm manages to solve the press line optimisation problem efficiently. This is a step forward in press line optimisation since this is to the authors’ knowledge the first time a press line has been optimised efficiently in this way.

  • 36.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Automation Systems. Department of Signals and systems, Chalmers University of Technology.
    Improved Constructive Cooperative Coevolutionary Differential Evolution for Large-Scale Optimisation2016In: Computational Intelligence, 2015 IEEE Symposium Series on, 2016, p. 1703-1710, article id 7376815Conference paper (Refereed)
    Abstract [en]

    The Differential Evolution (DE) algorithm is widely used for real-world global optimisation problems in many different domains. To improve DE's performance on large-scale optimisation problems, it has been combined with the Cooperative Coevolution (CCDE) algorithm. CCDE adopts a divide-and-conquer strategy to optimise smaller subcomponents separately instead of tackling the large-scale problem at once. DE then evolves a separate subpopulation for each subcomponent but there is cooperation between the subpopulations to co-adapt the individuals of the subpopulations with each other. The Constructive Cooperative Coevolution (C3DE) algorithm, previously proposed by the authors, is an extended version of CCDE that has a better performance on large-scale problems, interestingly also on non-separable problems. This paper proposes a new version, called the Improved Constructive Cooperative Coevolutionary Differential Evolution (C3iDE), which removes several limitations with the previous version. A novel element of C3iDE is the advanced initialisation of the subpopulations. C3iDE initially optimises the subpopulations in a partially co-adaptive fashion. During the initial optimisation of a subpopulation, only a subset of the other subcomponents is considered for the co-adaptation. This subset increases stepwise until all subcomponents are considered. The experimental evaluation of C3iDE on 36 high-dimensional benchmark functions (up to 1000 dimensions) shows an improved solution quality on large-scale global optimisation problems compared to CCDE and DE. The greediness of the co-adaptation with C3iDE is also investigated in this paper.

  • 37.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Manufacturing Processes. Chalmers.
    Optimised Control of Sheet Metal Press Lines2014In: Proceedings of the 6th International Swedish Production Symposium 2014 / [ed] Stahre, Johan, Johansson, Björn & Björkman, Mats, 2014, p. 1-9Conference paper (Refereed)
    Abstract [en]

    Determining the control parameters for sheet metal press lines is a large scale and complex optimisation problem. These control parameters determine velocities, time constants, and cam values of critical interactions between the equipment. The complexity of this problem is due to the nonlinearities and high dimensionality. Classical optimisation techniques often underperform in solving this kind of problems within a practical timeframe. Therefore, specialised techniques need to be developed for these problems. An existing approach is simulation-based optimisation, which is to use a simulation model to evaluate the trial solutions during the optimisation. In this paper, an efficient simulation-based optimisation algorithm for large scale and complex problems is proposed. The proposed algorithm extends the cooperative coevolutionary algorithm, which optimises subproblems separately. Hence, the optimisation problem must be decomposed into subproblems that can be evaluated separately. To optimise the subproblems, the proposed algorithm allows using embedded deterministic algorithms, next to stochastic genetic algorithms, getting the flexibility of using either type. It also includes a constructive heuristic that creates good initial feasible solutions to expedite the optimisation. The extension enables solving complex, computationally expensive problems efficiently. The proposed algorithm has been applied on an automated sheet metal press line from the automotive industry. The objective is to find control parameters that maximise the line’s production rate. The results show that the proposed algorithm manages to find optimal control parameters efficiently within the practical timeframe. This is a step forward in press line optimisation since to the authors’ knowledge this is the first time a press line has been optimised efficiently in this way.

  • 38.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Automation Systems.
    Simulation-based Time and Jerk Optimisation for Robotic Press Tending2015In: Modellling and Simulation: The European simulation and modelling conference 2015, ESM 2015, Ostende: ESM , 2015, p. 377-384Conference paper (Refereed)
    Abstract [en]

    Increased production rate and robot motion smoothness in a sheet metal press line are essential. Smooth robot motions avoid unplanned production interruptions and excessive wear of the robots. Reaching high production rate and smooth motions requires tuning of the tending press robot control to minimise the cycle time and jerk. Doing this for a press line with multiple robots is a complex large-scale problem. To model such problems for the optimisation process, computer simulations become almost essential. This work presents simulation-based optimisation of the time and jerk of robotic press tending operations and investigates the importance of including the robot motion’s smoothness. An optimiser works in concert with a simulation model of a sheet metal press line and its parametrised control system. The effect of including jerk minimisation in the objective function is tested on a real-world problem concerning a sheetmetal press line. The results illustrate the importance of including jerk-minimisation as an objective in the optimisation.Furthermore, the performance of this approach is compared with manual tuning by experienced operators. The results show that the proposed simulation-based optimisation approach outperforms manual tuning.

  • 39.
    Gull Karlsson, Marcus
    University West, Department of Engineering Science, Division of Automation Systems.
    Utredning beträffande förutsättningar för sammankoppling över elnätsföretag2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor´s thesis is conducted on behalf of Trollhättan Energi AB (TEAB). The bachelor´s thesis is an investigation of conditions for interconnection of TEAB and Hjärtum Elförenings electrical grids.

    The current electrical grids are radial electrical grids and means that it can only be fed from one cable end. An interconnection would allow for sectional operation of the electrical grid. This means input opportunities from both cable ends and that the electrical grid becomes more safely, reliably and efficiently.

    Suggestion for new electrical grids which parts of TEAB and Hjärtum Elförenings electrical grids are interconnected has been developed. With the new suggestions becomes the electrical grid more reliable and complies with legal and regulatory requirements.

    The calculations that are underpinning the work is theoretical. Therefore, a continued planning and research in the subject should be performed before the electrical grids are interconnected.

    Budget price for the reconstruction of the electrical grids have been estimated to be about 700 000 SEK and the investment is considered essential for the interconnection.

  • 40.
    Gustavsson Christiernin, Linn
    et al.
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Augustsson, Svante
    University West, Department of Engineering Science, Division of Automation Systems.
    Christiernin, Stefan
    University West, Department of Social and Behavioural Studies.
    Safety Critical Robot Programming and Testing for Operations in Industrial Co-production2014In: IEEE Conference Publications, 2014, p. 29-32Conference paper (Refereed)
  • 41.
    Hagqvist, Petter
    University West, Department of Engineering Science, Division of Automation Systems. Department of Signals and Systems Automatic control, Automation and Mechatronics, Chalmers University of Technology.
    Non-intrusive instrumentation and estimation: Applications for control of an additive manufacturing process2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    For integration of additive manufacturing into industrial production, there is a need for capable yet robust automation solutions. Such solutions are to ensure consistent process outputs, both with regard to deposit geometry and material properties. In this thesis, instrumentation and control solutions have been investigated for the laser metal wire deposition additive manufacturing process. This particular process is promising with regard to e.g. high deposition rates and negligible material waste. However, due to its inherent dynamics, it requires automatic control in order to prove competitive. A large number of process parameters affect the resulting quality of the deposit. Successful control of these parameters is crucial for turning laser metal wire deposition into an industrially tractable process. This requires relevant and reliable process information such as the temperature of the deposit and the positioning of the tool relative to the workpiece. Due to the particular requirements of instrumenting the process, only non-intrusive measurement methods are viable. In this thesis, such measurement solutions are presented that advance automatic control of the laser metal wire deposition. In response to the need for accurate temperature measurements for the process, a new temperature measurement method has been developed. By adopting the novel concept of temporal, rather than spectral, constraints for solving the multispectral pyrometry problem, it opens up for temperature measurements which compensates for e.g. an oxidising deposit. For maintaining a good deposition process in laser metal wire deposition, control of tool position and wire feed rate is required. Based on measurements of resistance through the weld pool, a simple yet well performing control system is presented in this thesis. The control system obtains geometrical input information from resistance measurements made in-situ, and feeds this information to an iterative learning controller. This results in a robust, cheap and practical control solution for laser metal wire deposition, which is suitable for industrial use and that can easily be retrofitted to existing equipment.

  • 42.
    Hagqvist, Petter
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation Systems.
    Heralic, Almir
    GKN Aerospace.
    Automation of a laser welding system for additive manufacturing2015In: Proceedings of the 2015 IEEE International Conference on Automation Science and Engineering / [ed] Kazuhiro Saitou, Univ. of Michigan, 2015, p. 900-905Conference paper (Refereed)
    Abstract [en]

    This paper presents the benefits and challenges ofusing a standard robotised laser welding cell for additive manufacturing(AM). Additive manufacturing, sometimes denoted3D-printing or rapid prototyping, has lately met strong interestin several areas of society, and a variety of technologies andmaterials have been in focus. The current paper summarisesautomation efforts for AM of advanced aero engine componentsusing high power laser with welding optics as power source formelting metal wire and using an industrial robot for obtaininga 3-dimensional feature shape. The challenges are related to theprocess itself encountering high and repeated temperatures withmelting and solidification of the metal as the main players. Themajor research solutions discussed in this paper are relatedto automation issues for obtaining a stable process and tohave control of the temperatures and temperature changes thatthe metals encounter during the process. The solutions aresuccessfully implemented in an industrial laser welding cell.

  • 43.
    Harati, Ebrahim
    et al.
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Ottosson, Mattias
    University West, Department of Engineering Science, Division of Automation Systems.
    Karlsson, Leif
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Svensson, Lars-Erik
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Non-destructive measurement of weld toe radius using Weld Impression Analysis, Laser Scanning Profiling and Structured Light Projection methods2014In: Proceedings of First International Conference on Welding and Non Destructive Testing (ICWNDT2014), 2014, p. 1-8Conference paper (Refereed)
  • 44.
    Hatefipour, Saeid
    et al.
    University West, Department of Engineering Science, Division of Automation Systems. saeid@termisk.se.
    Ahlberg, Jörgen
    Linköping University.
    Wren, Joakim
    University West, Department of Engineering Science, Division of Automation Systems.
    Runnemalm, Anna
    University West, Department of Engineering Science, Division of Automation Systems.
    Thermal non-destructive testing: modeling, simulation and experiments for improved localization of hidden defects2014In: The 12th International Conference on Quantitative Infrared Thermography, 2014, p. 1-8Conference paper (Refereed)
    Abstract [en]

    During the last decades, a substantial amount of research and practical work has been conducted on non-destructive testing of materials using thermography. The performed studies elucidate the potential of various types of thermal non-destructive testing (TNDT) for different materials and applications, including various types of defects. This paper presents a method for detecting in-depth defects in metallic materials and a simulation model for the heat transfer in the material. Experiments are performed on a test specimen with artificial defects (flat-bottom holes). The detection method exploits spatiotemporal analysis in order to find deviations from a model of normality, and shows novel results. Thermal modelling is performed in order to have a base-line simulation model enable us to (a) investigate affecting parameters without repeating the experiments and (b) generalize the results and extend their validity to other cases. Results show that there is an acceptable compliance between simulated and measured thermal data. 

  • 45.
    Hattinger, Monika
    et al.
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Eriksson, Kristina
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Malmsköld, Lennart
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Lars
    University West, Department of Economics and IT, Divison of Informatics.
    E-learning Readiness and Absorptive Capacity in the Manufacturing Industry2014In: International Journal of Advanced Corporate Learning, ISSN 1867-5565, E-ISSN 1867-5565, Vol. 7, no 3, p. 33-40Article in journal (Refereed)
    Abstract [en]

    The manufacturing industry constantly strive to develop the competencies of their expert production engineers in order to achieve and maintain a competitive advantage. Research shows that the absorptive capacity of a firm is central in order to reach such a goal. The absorptive capacity is the firm´s ability to recognize the value of new external information, assimilate it, and apply it to commercial ends, and thereby exploit the conditions for innovation. In this paper the concept of absorptive capacity is used as a lens for analyzing managerial rationales for engaging in technology enhanced competence development projects. Through interviews with key informants in 15 manufacturing firms we study the capabilities and readiness that organizations need for participation in e-learning initiatives. We present a framework of readiness for technology enhanced competence development comprised of the following interrelated constructs; awareness, e-learning maturity, dynamic capability and co-creativity. Results show a broad variation of levels within the constructs among the firms. Notable is the low level of e-learning maturity and dynamic capability. We argue that e-learning maturity is dependent on all four constructs.

  • 46.
    Hattinger, Monika
    et al.
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Eriksson, Kristina
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Malmsköld, Lennart
    University West, Department of Engineering Science, Division of Automation Systems. Chalmers University of Technology, Department of Product and Production Development,.
    Svensson, Lars
    University West, Department of Economics and IT, Divison of Informatics.
    Work-Integrated Learning and Co-creation of Knowledge: Design of collaborative technology enhanced learning activities2014In: Proceedings of the 37th Information Systems Research Seminar in Scandinavia (IRIS 37) / [ed] Ahmad Ghazawneh, Jacob Nørbjerg and Jan Pries-Heje, Ringsted, 2014, p. 1-15Conference paper (Refereed)
    Abstract [en]

    In this paper we aim to understand management’s perceptions of knowledge and competence development to inform the design of technology enhanced learning activities integrated in the workplace. Work-integrated learning can be viewed with the university lens on studies of formal education integrated in the workplace setting, but here we rather emphasize the conditions of the workplace as implications for design of successful e-learning initiatives. We conducted interviews with 15 manufacturing industries in Sweden and used qualitative content analysis approach to interpret the text data. Results show that companies describe a rich variation of work-integrated learning activities, but the step towards external collaboration with academia for co-production of knowledge is marginal. Also, broad-minded work for innovations is limited. This imply the need for well-planned design of richer collaborative acitivites between academia and organizations through use of media technology to encourage competence development.

  • 47.
    Hermawatia, Setia
    et al.
    Human Factors Research Group, Faculty of Engineering, The University of Nottingham.
    Lawson, Glyn
    Human Factors Research Group, Faculty of Engineering, The University of Nottingham.
    D'Cruz, Mirabelle
    Human Factors Research Group, Faculty of Engineering, The University of Nottingham.
    Arlt, Frank
    Adam Opel AG – General Motors Company, Rüsselsheim, Germany.
    Apold, Judith
    Adam Opel AG – General Motors Company, Rüsselsheim, Germany.
    Andersson, Lina
    VOLVO Group, Gothenburg.
    Gink Lövgren, Maria
    VOLVO Group, Gothenburg.
    Malmsköld, Lennart
    University West, Department of Engineering Science, Division of Automation Systems. Volvo Technology.
    Understanding the complex needs of automotive training at final assembly lines2014In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 46, p. 144-157Article in journal (Refereed)
    Abstract [en]

    Automobile final assembly operators must be highly skilled to succeed in a low automation environment where multiple variants must be assembled in quick succession. This paper presents formal user studies conducted at OPEL and VOLVO Group to identify assembly training needs and a subset of requirements; and to explore potential features of a hypothetical game-based virtual training system. Stakeholder analysis, timeline analysis, link analysis, Hierarchical Task Analysis and thematic content analysis were used to analyse the results of interviews with various stakeholders (17 and 28 participants at OPEL and VOLVO, respectively). The results show that there is a strong case for the implementation of virtual training for assembly tasks. However, it was also revealed that stakeholders would prefer to use a virtual training to complement, rather than replace, training on pre-series vehicles.

  • 48.
    Hjalmarsson, Malin
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Bergvall, Louise
    University West, Department of Engineering Science, Division of Automation Systems.
    Integrering och optimering av nya produktflöden2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 49.
    Hogmalm, William
    University West, Department of Engineering Science, Division of Automation Systems.
    Undersökning av visionsystem för hantering av trämaterial i automationssystem2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    University West is involved in research in automation and production technology. One project is to investigate the opportunity of assembling wood constructions for prefabricat-ed houses with robots in an automated system instead of manual assembly. Automated production of wood constructions is an opportunity for house manufacturers to develop a more competitive assembling process with high and consistent quality. One problem that occurs when robots move the wooden parts is that the material position misaligns due to variations in the material shape. The thesis work has been focused on investigating how a vision system can be designed to provide information to the robots how the material is placed. The report gives a description of the items included in a vision system and the working methodology for the system. It has been investigated which major factors that is needed to create a successful vision application. Experimental samples have been made by using a vision camera for image acquisition when the wood material is placed on the as-sembling table. The images were then image processed and analyzed in computer to find out if the desired information can be read from them. The difficulties that occur when the images are obtained have been investigated. It has been investigated how a vision program can be designed to perform measurements in the image to determine whether a placement is correct so the assembling can be performed. The focus was to make a program that is flexible and extendable with more functions so it can be adapted in many different assem-bly steps. By using the result from the program the robots shall be able to have information of how the material shall be corrected. The investigation has shown good potential in de-veloping a vision based inspection system to correct the position and shape changes that may occur in wood handling. It has also demonstrated the challenge, in building a success-ful application, with creating a well optimized lighting that illuminates the desired parts of the images. The study has shown the opportunities in get accurate results from images ob-tained at close range, as when camera is mounted on the robot. The results have also shown that more studies are suitable to implement in order to investigate which alternative and complementary technologies that may be appropriate to use in this challenge

  • 50.
    Jakobsson, Tomas
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Salman, Sebastian
    University West, Department of Engineering Science, Division of Automation Systems.
    Provplan för validering av reläskyddmed Omicron CMC 3562015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vattenfall Eldistribution AB (Vattenfall) got an interest in standardising the reoccurring maintenance tests in the power. During the coming years Vattenfall will be having their maintenance work in the power monitoring facility out for procure which can result in several different actors with mixed skills may commit to the maintenance of a certain area. To ensure that the testing of relay protections will be performed the same way by all of the drafted maintenance staff Vattenfall wants a testing manual that the staff can follow. Vattenfall hopes that the manual will be of use for the staff to ease the testing on the medium voltage level. This thesis contains the subject safety relays and describes the relay functions, the testing equipment and the software associated whit the testing equipment. This thesis also contains theory regarding safety relays and some specific functions in the relay. There's also an explanation regarding the safety relay REF620 from ABB within the theory regarding the tested functions. The validated functions that are explained in the thesis are over and under current, over and under voltage, frequency protection and earth fault protection. The computer program from Test Universe 3.00 from Omicron was used for validating the functions. This program controls the testing equipment Omicron and sends the voltage and current quantities to the safety relay, the quantities are used to simulate faults in the distribution network. The simulation of the faulted network shows that the ABB REF620 safety relay meets the demands on the safety limits on the start and trigger values. In the few cases the safety relay didn't meet the requirements there were a discussion regarding the causes of the failed test.

    A part of the issue could be that the mechanical relay inside the safety relay may cause some delay time, other reasons for the delay time may be due to preprogramed safety marginal that makes the safety relay act quicker or slower than expected. Despite some test failed due to the delay it's all in the valid range of the safety marginal. The Omicron CMC 356 in combination with the testing software is an effective tool for testing safety relays. In the software it's easy to access the error reports and results.

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