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  • 1.
    Abdalrhman, Slah Aldeen
    University West, Department of Engineering Science, Division of Production Systems.
    Virtual model of a production process: Seam sealing line at Scania2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The concept of digital factories is becoming more popular among the manufactures due to its contributions in simplifying the work of plant engineers and reducing time to market of the products [1]. The main aim of this thesis was to investigate the possible applications of a digital copy of production processes by creating a virtual model of a seam sealing line in the paint department at Scania in Oskarshamn. The main usage of the virtual model was to perform offline programming of the robots. The benefits of offline programming were investigated and compared to online programming. Some comparisons between offline and online programming were made when it comes to the time needed for programming, the accuracy of generated robot paths, the workflow of both approaches and the required knowledge to turn from online programming to offline programming.

    The result of the conducted experiment showed that the time of robot programming can be reduced, and the accuracy of robot paths increases by implementing an offline programming tool. The other application of virtual which was investigated in this thesis was virtual commissioning. Virtual commissioning is a method used to test and validate robot and control (PLC) programs in a virtual environment before implementing in the real plant. The software in the loop was selected as an approach for building the virtual commissioning model after presenting the different existed approaches. The result of the model showed great benefits of virtual commissioning not just in reducing the time of traditional of the new built line but even when replacing parts in an already existing manufacturing. Virtual commissioning is still new in the manufacturing, therefore, there are many issues which should be solved to get an optimal model that imitates perfectly the real plant.

  • 2.
    Adolfsson, Sebastian
    University West, Department of Engineering Science, Division of Production System.
    RatSLAM with Viso2: Implementation of alternative monocular odometer2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a ROS (Robot Operating System) version of Open RatSLAM, [1] [2], was tested with Viso2 [3] as an alternative monocular odometer. A land based rover [4] was used to perform data acquisition and a remote control tool was developed to facilitate this procedure, implemented as ROS nodes on both Ubuntu 16.04 and on Android 7.0.An additional requirement that comes from using Viso2 is the need for camera information together with the image stream, which might require camera calibration. A ROS node to manually add this camera information was made as well as a node to change the generated odometry message from Viso2 to a form that RatSLAM uses. The implemented odometer uses feature tracking to estimate motion, which is fundamentally different to matching intensity profiles which the original method does and can hence be used when different properties of the visual odometry function is desired. From experiments, it was seen that the feature tracking method from Viso2 generated amore robust motion estimate in terms of real world scale and it was also able to better handle environments of varying illumination or that contains large continuous surfaces of the same colour. However, the feature tracking may give slight variations in the generated data upon successive runs due to the random selection of features to track. Since the structure of RatSLAM gives the system ability to make loop closures even with large differences in position, an alternative odometry does not necessarily give a significant improvement in performance of the system in environments that the original system operates well in. Even though both algorithms show difficulty with estimating fast rotations, especially when the camera view contains areas with few features, the performance improvement in Viso2 together with its ability to better maintain the real-world scale motivates its usefulness. The source code, as well as instructions for installation and usage is public

  • 3.
    Adolfsson, Sebastian
    University West, Department of Engineering Science, Division of Production System.
    RatSLAM with Viso2: Implementation of alternative monocular odometer2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a ROS (Robot Operating System) version of OpenRatSLAM, [1] [2], was tested with Viso2 [3] as an alternative monocular odometer. A land based rover [4] was used to perform data acquisition and a remote control tool was developed to facilitate this procedure, implemented as ROS nodes on both Ubuntu 16.04 and on Android 7.0.  An additional requirement that comes from using Viso2 is the need for camera information together with the image stream, which might require camera calibration. A ROS node to manually add this camera information was made as well as a node to change the generated odometry message from Viso2 to a form that RatSLAM uses. The implemented odometer uses feature tracking to estimate motion, which is fundamentally different to matching intensity profiles which the original method does and can hence be used when different properties of the visual odometry function is desired. From experiments, it was seen that the feature tracking method from Viso2 generated a more robust motion estimate in terms of real world scale and it was also able to better handle environments of varying illumination or that contains large continuous surfaces of the same colour. However, the feature tracking may give slight variations in the generated data upon successive runs due to the random selection of features to track. Since the structure of RatSLAM gives the system ability to make loop closures even with large differences in position, an alternative odometry does not necessarily give a significant improvement in performance of the system in environments that the original system operates well in. Even though both algorithms show difficulty with estimating fast rotations, especially when the camera view contains areas with few features, the performance improvement in Viso2 together with its ability to better maintain the real-world scale motivates its usefulness.  The source code, as well as instructions for installation and usage is public.

  • 4.
    Almardoud, Nour
    University West, Department of Engineering Science, Division of Production Systems.
    Identifying the Potentials for Moving from Manual to Automated Systems2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Parker Hannifin Manufacturing Sweden AB is an international company with manufactory sites all around the world. The site in Trollhättan is part of the Pump & Motor Division Europe. The Factory has worked a lot with automating the manufacturing section. Many robots are implemented in the factory to produce the simple parts which need to be assembled to interduce the last product. Parker are now interested in starting the process of automating the assembly stations for the 3 products they produce in this site. The three products are Truck pumps, fixed and variable displacement pumps (LBP), variable hydraulic motors (VM) and fixed hydraulic motors (FM). Each one of the three types has different sizes and different series.

    This work focuses on analysing the current system which consists of seven assembly station, 101, 102, 201, 202, 203, 301 and 302. After analysing the current system, a work on finding the potentials for moving from manual to semi-or automated stations for each station is presented. Seven potentials were found. The first potential which handle a bout a central pressing robot cell is a common potential for all the stations, and the other potentials are for each station separately. Testing and validation for all the potentials where the automation can be implemented and started with, the cycle time for the operations and the productivity, the workspace and material handling in addition to the level of the ergonomics for these stations.

    The complexity of these solutions, the advantages and disadvantages and a safety analyses are also presented. And how to optimize the current system for reaching a high level of automation is discussed.

  • 5.
    AlNabulsi, Yasan
    University West, Department of Engineering Science, Division of Production System.
    Robot motion control based on 3D mouse tracking2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The manufacturing industry and associated systems are being developed in an increasing manner to cover the market needs, where the manufacturing companies are continuously racing and competing to achieve high productivity rate and better production quality. In this thesis work, an advanced method for motion control of industrial robots has been investigated and implemented. This method is based on motion tracking of a 3DSpaceMouse, which was used to perform movements by the operator. The benefits and disadvantages of this method were discussed in this thesis work. It mainly showed a high accuracy in response to the motion applied by the 3DSpaceMouse, and a great stability regarding the programming environment that was used to build it. The movements applied by the 3DSpaceMouse were successfully captured and stored in variables in the programming platform. The capturing and storing process was successfully created as a package and prepared to be exported for usage by other software. Complete simulation was performed for an industrial robot, and successful communications among the various hardware and software components of this solution were accomplished. This has formed a complete integrated solution that has also included a user-friendly HRI. This HRI made it easy and simple to track the motion control processes and establish connections with the robot controller. Thus, it can be considered a feasible solution for motion control of industrial robots, which can be used by the manufacturing companies. Several tests and verification processes were carried out to obtain accepted results and to succeed in implementing a working model. Some errors and unexpected events have appeared during the work, which required handling in order to achieve a working integrated system.

  • 6.
    Asad, Ahmed
    et al.
    University West, Department of Engineering Science, Avdelningen för produktionssystem (PS).
    Sallander, Rikard
    University West, Department of Engineering Science, Avdelningen för produktionssystem (PS).
    Balansering och tidsoptimering av materialsatsning till F12-monteringen på Parker PMDE Trollhättan2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In industries, the management tools of Lean Production are used to develop and streamline operations in a way to reduce waste and lead times in all processes. Parker PMDE in Trollhättan manufactures hydraulic machines. Since the 90´s, Parker has pursued business development under the management principles of Lean Production. One of the next steps in Parkers continuous improvement was to explore opportunities to develop a kitting department so that a worker could provide the assembly with the material quickly without surplus resources. In the current situation, there is an imbalance from the kitting station towards the tact times in the assembly station because it takes longer at the kitting station to pick materials for four hydraulic machines, than it takes for the assembly station to consume these kits of materials.The aim of the thesis was to develop suggestions for improvement where a worker could perform the kitting process in less than 16 minutes. The interim objectives were to do a survey of the times and activities within the kitting process. The boundaries of the project was not to examine processes outside the kitting station. The project was designed according to DMAIC methodology, which is a project model for fact-based problem solving and clear structure. The methods used in the data collection were observation and analysis of video footage applying the software called AviX Method. Video recordings were categorized as different activities in the kitting process such as transport, picking, scanner time, pre-assembly and uncategorized time. Activities that were time consuming and did not add value to the process were identified. These data measures were the basis for the solution proposals.Based on these results and using brainstorming, solution proposals were generated together with the engineers and material handlers. The solution proposals that met the objective of the project of picking a 4-set of materials in 16 minutes were: Pick by voice, Pick-by-light, Ring Scanner and Relocation of one pre-assembly operation. Pick by voice is considered to be the most appropriate solution for the company since it reduces picking times, scanning times and is a flexible system. Two more proposed solutions were developed that did not meet the objective of the project, but are considered worth investigating further based on Lean Production and ergonomic reasons. These proposed solutions consisted of changing the picking route and the installation of a magnetic lift.

  • 7.
    Bennulf, Mattias
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Production Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    Verification and deployment of automatically generated robot programs used in prefabrication of house walls2018In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 72, p. 272-276Article in journal (Refereed)
    Abstract [en]

    This paper presents a method for automating the generation, verification and deployment of robot programs used in prefabrication of walls for family houses. The making of robot programs is today performed manually by experts, i.e. implying high costs. This is a huge disadvantage since each wall can be unique. The work demonstrates, with implementation and testing, a method to automate the generation of robot programs for fabrication of walls made of wood. This includes the task of generating collision free paths, automatic verification of path performance and deploying to a real industrial robot with minimal human interaction. © 2018 The Authors. Published by Elsevier B.V.

  • 8.
    Bergström, Per
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Luleå, Sweden.
    Fergusson, Michael
    Xtura AB, Kungsbacka, Sweden.
    Folkesson, Patrik
    Xtura AB, Kungsbacka, Sweden.
    Runnemalm, Anna
    University West, Department of Engineering Science, Division of Production System.
    Ottosson, Mattias
    University West, Department of Engineering Science, Division of Production System.
    Andersson, Alf
    Chalmers University of Technology, Department of Product and Production Development, Gothenburg, Sweden.
    Sjödahl, Mikael
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Luleå, Sweden.
    Automatic in-line inspection of shape based on photogrammetry2016In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016, Lund: Swedish Production Academy , 2016, p. 1-9Conference paper (Refereed)
    Abstract [en]

    We are describing a fully automatic in-line shape inspection system for controlling the shape of moving objects on a conveyor belt. The shapes of the objects are measured using a full-field optical shape measurement method based on photogrammetry. The photogrammetry system consists of four cameras, a flash, and a triggering device. When an object to be measured arrives at a given position relative to the system, the flash and cameras are synchronously triggered to capture images of the moving object.From the captured images a point-cloud representing the measured shape is created. The point-cloud is then aligned to a CAD-model, which defines the nominal shape of the measured object, using a best-fit method and a feature-based alignment method. Deviations between the point-cloud and the CAD-model are computed giving the output of the inspection process. The computational time to create a point-cloud from the captured images is about 30 seconds and the computational time for the comparison with the CAD-model is about ten milliseconds. We report on recent progress with the shape inspection system.

  • 9.
    Billett, Robin
    University West, Department of Engineering Science, Division of Production Systems.
    Examining the impact of light on the perceivability and compatibility of different materials2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A car's interior uses many different surface materials. For the interior design scheme to uphold a high level of quality, these materials must harmonise and be visually compatible. Experience and research have proven that a material's appearance and colour can be subject to change when under various types of light. Compositions of surface materials can also influence the way they are perceived together when the light they are illuminated by changes.

    A study was performed where 21 interior surface materials were examined under a selection of white and coloured light. The materials consisted of ten décor samples, four grained plastic samples, four grained vinyl and leather samples and three chrome samples. The white light used consisted of daylight (CIE illuminant D65 at 6500 °K), fluorescent light (CIE illuminant F11 at 4000 °K) and incandescent light (CIE illuminant A at 2800 °K). The coloured light used consisted of six colours: red, green, blue, yellow, violet and turquoise. The materials were examined using the paired comparison method under all nine types of light, and the results were documented. Patterns were identified in the results and conclusions regarding different aspects of the materials were drawn.

    The results showed that light has a strong impact on the perceivability and compatibility of materials, which aligned with previous research. Light materials were more affected by changes in light than dark materials, often taking on the colour of the light entirely. Red, green and blue light caused many metameric issues and materials were often straining to observe. Violet light caused less issues, and yellow and turquoise light even fewer. The results were summarised into a list of conclusions relating to the materials and their properties.

    Implications of the results were discussed for three separate aspects: perceived quality, design and environmental. It is also important to keep in mind that conclusions drawn from results based on subjective judgements will always be prone to inaccuracies. Therefore, caution is advised when applying the results of this thesis, and compatibility tests should always be performed in addition to applying the conclusions.

  • 10.
    Bolmsjö, Gunnar
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Bennulf, Mattias
    University West, Department of Engineering Science, Division of Production Systems.
    Zhang, Xiaoxiao
    University West, Department of Engineering Science, Division of Production Systems.
    Safety System for Industrial Robots to Support Collaboration2016In: Advances in Ergonomics of Manufacturing: Managing the Enterprise of the Future. Proceedings of the AHFE 2016 International Conference on Human Aspects of Advanced Manufacturing, July 27-31, 2016, Walt Disney World®, Florida, USA / [ed] Christopher Schlick, Stefan Trzcieliński, Springer International Publishing , 2016, p. 253-265Chapter in book (Refereed)
    Abstract [en]

    The ongoing trend towards manufacturing of customized products generates an increased demand on highly efficient work methods to manage product variants through flexible automation. Adopting robots for automation is not always feasible in low batch production. However, the combination of humans together with robots performing tasks in collaboration provides a complementary mix of skill and creativity of humans, and precision and strength of robots which support flexible production in small series down to one-off production. Through this, collaboration can be used with implications on reconfiguration and production. In this paper, the focus and study is on designing safety for efficient collaboration operator—robot in selected work task scenarios. The recently published ISO/TS 15066:2016 describing collaboration between operator and robot is in this context an important document for development and implementation of robotic systems designed for collaboration between operator and robot.

  • 11.
    Bolmsjö, Gunnar
    et al.
    Linnaeus University, Växjö, Sweden.
    Ferreira Magalhães, Ana Catarina
    University West, Department of Engineering Science, Division of Production Systems. University West, Department of Engineering Science, Division of Welding Technology.
    Cederqvist, L.
    SKB AB, Oskarshamn, Sweden.
    De Backer, Jeroen
    University West, Department of Engineering Science, Division of Production Systems.
    Robotic Friction Stir Welding of complex geometry and mixed materials2018In: 50th International Symposium on Robotics, ISR 2018, VDE Verlag GmbH , 2018, p. 35-41Conference paper (Refereed)
    Abstract [en]

    Friction stir welding (FSW) is a solid state process for joining materials which has demonstrated advantages compares with other methods which include joining of mixed materials, hard to weld alloys and consistent and high quality. This paper presents a study of robotic FSW initiated by Volvo Skövde plant to join an insert workpiece of extruded aluminium with a cylinder block of aluminium casting. A three-stage procedure was decided to determine the feasibility to apply robotic FSW. The stages included study of welding the mixed materials, weld along the complex joint line with holes and channels close to the joint, and finally welding the cylinder block. The results based on preliminary analysis indicate that the final tests were successful and the process is feasible for the challenging case study. However, further studies are recommended in order to identify the operating parameters window, tool design, and control of the process in order to optimize productivity and quality. © VDE VERLAG GMBH

  • 12.
    Brandt, Otto
    University West, Department of Engineering Science, Division of Production System.
    Virtual commissioning of the PTC production line2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 13.
    Broberg, Patrik
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Runnemalm, Anna
    University West, Department of Engineering Science, Division of Production Systems.
    Analysis algorithm for surface crack detection by thermography with UV light excitation2016In: Quantitative InfraRed Thermography 2016: Abstracts / [ed] Kaczmarek, M. & Bujnowski, A., Gdańsk, Poland: Publishing Gdańsk University of Technology , 2016, p. 144-149Conference paper (Refereed)
    Abstract [en]

    Surface crack defects can be detected by IR thermograpgy due to the high absorption of energy within the crack cavity. It is often difficult to detect the defect in the raw data, since the signal easily drowns in the background. It is therefore important to have good analysis algorithms that can reduce the background and enhance the defect. Here an analysis algorithm is presented which significantly increases the signal to noise ratio of the defects and reduces the image sequence from the camera to one image.

  • 14.
    Carlsson, Henrik
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Nilsson, Jim
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering. University West, Department of Engineering Science, Division of Production Systems.
    Automated Generation of Discrete Event System Simulation Models for Flexible Automation2011In: The 21st International Conference on Flexible Automation and Intelligent Manufacturing: Taichung, Taiwan, June 26-29 2011, 2011, p. 825-832Conference paper (Refereed)
    Abstract [en]

    Flexible automation cells with rapid product changes are an important competitive advantage for industries today. These cells can increase a company’s productivity and thereby increase their profits. A flexible cell shall be able to handle different products with none or minimal changes to the cell itself. A powerful tool, which can be used to analyse and verify such cells, is discrete event system simulation. Problems such as potential bottlenecks, deadlocks, answers to "what-if" questions and the level of resource utilisation can be gathered. The drawback of discrete event system simulation is that the modelling task is both time consuming and difficult to accomplish. Furthermore, state-of-the-art discrete event system simulation tools that are used in the industry today are not suitable for flexible automation. If the production scenario is changed, e.g. introduction of a new product, the simulation and modelling has to be redone and this is both time consuming and tedious. In this paper a new approach will be presented that enables discrete event simulation models to be generated automatically. The models are generated from information retrieved from a PLM/PDM database system, which is shared among other engineering tools such as robot simulation, CAD and process planning. Hence, when the cell and the database are updated a new model can easily be generated. The database is also connected to the real cell so up-to-date data can be retrieved from the real cell. The model generator described in this paper was implemented and tested in a discrete event system simulation tool and showed promising results. With this approach it is possible to handle flexible automation cells more effectively in a process planning stage.

  • 15.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Production System. TWI Ltd, Cambridge, UK.
    Martin, Jonathan
    TWI Ltd, Cambridge, UK.
    Wei, Sam
    TWI Ltd, Cambridge, UK.
    Robotic Stationary Shoulder FSW: benefits and limitations2016In: Conference proceedings of the 11th International Symposium on Friction Stir Welding, 2016Conference paper (Refereed)
  • 16.
    Devapal, Arihant
    University West, Department of Engineering Science, Division of Production Systems.
    Automation Solution for Manual Assembly Station2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis is about finding a solution for the manual assembly process of making the industrial pumps which is currently present in the company named Parker in Boras. A number solutions is formed and simulated with the help of the software known as ABB Robot Studio. From all the solutions one final solution is thought through the project.

    The result is automation solution which is simulated with using two robots and other components to reduce the cycle time, improve the quality of the product, ensures safety for the workers thus resulting in overall higher production rate.

  • 17.
    Elefante, Arianna
    et al.
    University of Bari, Physics Department, Via Amendola 173, 70126 Bari, Italy.
    Nilsen, Morgan
    University West, Department of Engineering Science, Division of Production Systems.
    Sikström, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Production Systems.
    Maggipinto, Tommaso
    University of Bari, Physics Department, Via Amendola 173, 70126 Bari, Italy.
    Ancona, Antonio
    University West, Department of Engineering Science, Division of Production Systems. IFN-CNR Institute for Photonics and Nanotechnologies, Physics Department, Via Amendola 173, 70126 Bari, Italy.
    Detecting beam offsets in laser welding of closed-square-butt joints by wavelet analysis of an optical process signal2019In: Optics and Laser Technology, ISSN 0030-3992, E-ISSN 1879-2545, Vol. 109, p. 178-185Article in journal (Refereed)
    Abstract [en]

    Robotized laser beam welding of closed-square-butt joints is sensitive to the positioning of the laser beam with respect to the joint since even a small offset may result in a detrimental lack of sidewall fusion. An evaluation of a system using a photodiode aligned coaxial to the processing laser beam confirms the ability to detect variations of the process conditions, such as when there is an evolution of an offset between the laser beam and the joint. Welding with different robot trajectories and with the processing laser operating in both continuous and pulsed mode provided data for this evaluation. The detection method uses wavelet analysis of the photodetector signal that carries information of the process condition revealed by the plasma plume optical emissions during welding. This experimental data have been evaluated offline. The results show the potential of this detection method that is clearly beneficial for the development of a system for welding joint tracking.

  • 18.
    Emanuelsson, Viktor
    et al.
    University West, Department of Engineering Science, Avdelningen för produktionssystem (PS).
    Wahlberg, Christoffer
    University West, Department of Engineering Science, Avdelningen för produktionssystem (PS).
    Omkonstruktion av fixtur avsedd för manuell svetskontroll av turbinmotorstativ2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor's thesis treats the production of a fixture for manual physical and visual weld inspection of an aircraft engine stand, 30k TEC (Turbine Exhaust Case), for GKN Aerospace in Trollhättan. The main problem is that the inspection of 30k TEC had not previously occurred to the extent that is current today. The purpose was to facilitate the inspection staff's work situation and to determine whether it is possible to use parts of a fixture adapted to a different aircraft engine stand.The work is based, for the project, on relevant methods that includes data collection, inter¬pretation of collected data, concept generation and concept selection. Interested parties were identified with their respective demands on the fixture and the environment. Concept proposals were generated along with interviews and observations of similar fixtures. The concept proposals went through a concept selection process, which resulted in a final concept.The final concept allows motorized rotation of the aircraft engine stand and it is equipped with supports which prevents the aircraft engine stand to fall off the fixture. The support prevents the turbine exhaust case from falling off during the inspection, which could result in both material damage to the aircraft engine stand and equipment as well as physical damage to the inspection staff. Due to the possibility to rotate the aircraft engine stand with a motor the fixture is classified as a machine and must therefore be CE marked by the manufacturer. The work therefore includes in-depth knowledge in the Machinery Directive and the requirements for CE marking of machines. To meet the ergonomic aspects for the inspection staff, guidelines for ergonomic work.The report presents the final concept and its included components. The employer's work deliverables consists of order documents ready to be sent to the manufacturer of the fix-ture containing drawings and parts lists. Both manufacturers and inspection staff have shown a positive attitude towards the outcome.

  • 19.
    Erichsen, Mathias
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Hallgren, Peter
    University West, Department of Engineering Science, Division of Production Systems.
    Automatiserat produktionsupplägg för fönstermoduler i trä2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor's thesis has been carried out at PTC in Trollhättan. The work has been a part of the larger project "Trämanufaktur – Tillverka i trä" where a potential product for manufacturing in a test & demo environment has been explored.

    The purpose of the thesis was to investigate how window modules are produced, but also to visualize and to evaluate a concept for manufacturing the window module. This manufacturing is planned to be carried out with the flexible robot cell, which is available at PTC in Trollhättan. The goal of the thesis was to find out if the window module is a suitable manufacturing product for the test & demo environment for the project "Trämanufaktur – Tillverka i trä".

    The development of manufacturing concepts required a definition of the window module, this was to clarify what its components are and what steps are made in the production. A definition of the module and an in-depth study of the woodworking industry was made through case studies on manufacturing companies and through a literature study.

    To visualize manufacturing concepts in RobotStudio, 3D models were produced of the manufacturing environment and the window module. With the help of visualizations, the concept that was best suited for the test & demo environment could be developed. This was done by evaluating different concepts regarding the project's limitations. The concept chosen was further evaluated, the result included a scope study and a time study for workflow in the current range of the robot.

    A discussion is made in the report on development potential for further studies, the result and concepts for manufacturing the window module outside the project's limitations.

    The conclusion that was established was that the product, window module is not suitable for being manufactured in existing robot cell as a part of the test & demo environment. This is because it will require either major reconstructions, a complicated fixture or a less than full reachability around the window module.

  • 20.
    Ericsson, Mikael
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Zhang, Xiaoxiao
    University West, Department of Engineering Science, Division of Production Systems.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Production Systems.
    Virtual Commissioning of Machine Vision Applications in Aero Engine Manufacturing2018In: Proceedings of The 15th International Conference on Control,Automation, Robotics and Vision, November 18-21, 2018, 2018, p. 1947-1952, article id 0293Conference paper (Refereed)
    Abstract [en]

    New aero engine design puts new demands on the manufacturing methods with increased automation level. Therefore, the use of vision sensors for control and guiding of industrial robots is being increasingly used. In such system, it is need to customise the machine vision system with real components in the real environment which is normally done close to the start-up of the production. This paper addresses a new concept for designing, programming, analysing, testing and verifying a machine vision application early in the design phase, called Virtual Machine Vision. It is based on a robot simulation software where the real machine vision application is simulated before the implementation in the production line. To verify the Virtual Machine Vision concept an advanced stereo vision application was used. Using two captured images from the robot simulated environment, camera calibration, image analysis and stereo vision algorithms are applied to determine a desired welding joint. The information of the weld joint, i.e. robot position and orientation for the weld path, are sent from the machine vision system to the robot control system in the simulation environment and the weld path is updated. The validation of the Virtual Machine Vision concept using the stereo vision application is promising for industrial use, and it is emphasised that the same programs are used in the virtual and real word.

  • 21.
    Eriksson, Kristina M.
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Chirumalla, Koteshwar
    Ericsson, Mikael
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    A novel blended learning course developed jointly between three universities to address competence development of professionals in digitalized manufacturing2019In: VILÄR 5-6 december 2019, University West, Trollhättan: Abstracts / [ed] Kristina Johansson, Trollhättan: University West , 2019, p. 6-7Conference paper (Other academic)
    Abstract [en]

    New competences and knowledge needs arises as manufacturing industry evolves and becomes increasingly digitalized. Facing this transformation, one of the challenges is the continuous and growing need for novel initiatives for competence development.The case portrayed here stems from a Swedish cross-university project aiming to jointly develop and offer courses for competence development of professionals in the manufacturing and IT sectors. The ambition is to increase the impact of the universities' respective efforts of meeting industry competence needs, where the continuous digital transformation entails that employees must develop or even change their qualifications.

    The case outlined focus co-production of a joint course package, at master level, between three universities and their respective company networks. Participating universities have long traditions in working closely with companies in research and education, where approaches for co-production have evolved over time. We make use of our joint understanding of the manufacturing industry's specific competence needs and our experiences of sustainable course formats for participants working full time.The joint course covers aspects of a manufacturing company on three levels: plant level i.e. material and production flows, cell level e.g. robotic simulation and visualisation, and system level i.e. data acquisition and monitoring through sensors. Each university is developing a course module of 2.5 ECTS, addressing a level respectively of their specialist competence. Participants are to complete assignments for each course module, i.e. for all three manufacturing levels, where the previous assignment provides an input to the next level, enabling the participants to encompass a holistic view of a manufacturing system. Participants need to combine study and work and at the same time they wish to extend their network, hence we are adopting a blended learning approach, where virtual labs and web conferences are mixed with physical meetings.A variety of challenges arise when designing such novel approaches: combining company networks, course design including online learning, planning of physical course meetings,

    joint promotion, common admission and validation process, financial models and more. However, engaging in partnerships with industry for knowledge transformation and development has the potential to become rewarding for all parties.

  • 22.
    Eriksson, Kristina M.
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Hattinger, Monika
    University West, Department of Engineering Science, Division of Production Systems.
    Participants Perspectives and Results from Competence Development Courses for Industrial Work Integrated Learning2019In: VILÄR 5-6 december 2019, University West, Trollhättan: Abstracts / [ed] Kristina Johansson, Trollhättan: University West , 2019, p. 7-8Conference paper (Other academic)
    Abstract [en]

    In a work practice of constant implementation of new manufacturing processes, competence development becomes crucial for practitioners within engineering fields such as production systems, additive manufacturing, industry 4.0 and machine learning. Industrial work is transforming and practitioners constantly need to learn both integrated in work practice and through flexible education.Given this, the purpose of this study is to analyse how participants engage in a unique initiative where courses targeting competence development for manufacturing industry have been co-constructed between one university and a network of companies. The longitudinal initiative (2013-ongoing) focus industry knowledge needs and e-learning design aiming for industrial work integrated learning. Over time a course format of five-week flexible e-learning courses of 2.5 ECTS, on master level, has evolved, and 30 courses within e.g. robotics, additive manufacturing and industrial digitalization, have been designed.

    The uniqueness lies in the opportunities continuously taken for co-construction of course design throughout and this has brought about a combination of different practices for collaboration between academia and industry. Course participants perspectives are specifically explored through focus group studies and a questionnaire survey. Between 2014 and spring 2019 a total of 367 participants took part in focus group sessions at the end of each course instance. The questionnaire was distributed in spring 2019 to 638 individuals and the response rate was 12% (77 respondents) of which 56 had completed one or more courses. While the response rate of the questionnaire is low, results confirm the findings from the focus group studies and indicates new aspects for further study.

    Outcomes from the focus groups show that practitioners feel that their own motives for learning are key for course participation. This is corroborated by the questionnaire results where 79% say they apply for the courses with ambition to study built on their own desire. The flexible e-learning format including virtual laboratories, web-conferencing and practical cases, is essential when combining full time work with competence development. This coupled with 89% of the questionnaire respondents finding the course content useful in relation to their own work, indicates the uniqueness of the initiative. Challenges persisting are the university's lack of capacity to swiftly respond to companies' skills needs and the nurture and development of the growing network that requires continued coordination. However, participants perspectives reveal the potential of how to empower co-construction of knowledge for industrial work integrated learning.

  • 23.
    Ferreira Magalhães, Ana Catarina
    et al.
    University West, Department of Engineering Science, Division of Welding Technology.
    Cederqvist, Lars
    SKB AB, Oskarshamn, Sweden.
    De Backer, Jeroen
    University West, Department of Engineering Science, Division of Production Systems.
    Håkansson, Emil
    Volvo Cars, Göteborg, Sweden.
    Ossiansson, Bruno
    Volvo Cars, Skövde, Sweden.
    Bolmsjö, Gunnar
    Linnaeus University, Växjö, Sweden.
    A Friction Stir Welding case study using Temperature Controlled Robotics with a HPDC Cylinder Block and dissimilar materials joining2019In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 46, p. 177-184Article in journal (Refereed)
    Abstract [en]

    The automotive industry is going through a radical transformation from combustion engines to fully electric propulsion, aiming at improving key performance indicators related to efficiency, environmental sustainability and economic competitiveness. In this transition period, it is important to continue the innovation of combustion engines for e.g. plug-in hybrid vehicles. This led Volvo Cars to pursue radically new manufacturing processes such as Friction Stir Welding (FSW). The work presented in this paper is a case study whereby feasibility of using FSW to join a reinforcement element into the aluminium casted Cylinder Block was studied. The complex geometry of the joint required a flexible five-axis manipulator, i.e. an industrial robot, as well as advanced process control, i.e. temperature feedback control, in order to maintain a consistent weld quality throughout the whole component. The process was successfully demonstrated in a lab environment and offers a cost-efficient solution while maintaining the durability and higher efficiency. The outcome of this study shows the great potential of implementing the FSW process in combination with High Pressure Die Casted components, such a Cylinder Block. © 2019 The Society of Manufacturing Engineers

  • 24.
    Ferreira Magalhães, Ana Catarina
    et al.
    University West, Department of Engineering Science, Division of Production Systems. University West, Department of Engineering Science, Division of Welding Technology.
    De Backer, Jeroen
    University West, Department of Engineering Science, Division of Production Systems.
    Bolmsjö, Gunnar
    Linnaeus University, Växjö, Sweden.
    Thermal dissipation effect on temperature-controlled friction stir welding: [Efeito da dissipação térmica inducida durante soldadura por friçcão linear sob controlo de temperatura]2019In: Soldagem & Inspeção, ISSN 0104-9224, E-ISSN 1980-6973, Vol. 24, article id e2428Article in journal (Refereed)
    Abstract [en]

    During Friction Stir Welding (FSW) of complex geometries, the thermal dissipation, induced by geometric features or the surrounding environment, may strongly affect the final weld quality. In order to guarantee a consistent weld quality for different conditions, in-process welding parameter adaptation is needed. This paper studies the effect of thermal dissipation, induced by the backing bar thermal conductivity, on the weld temperature and the temperature controller response to it. A new temperature sensor solution, the Tool-Workpiece Thermocouple (TWT) method, was applied to acquire online temperature measurements during welding. An FSW-robot equipped with temperature control, achieved by rotation speed adaptation, was used. AA7075-T6 lap joints were performed with and without temperature control. The cooling rate during welding was register plus macrographs and tensile tests were assessed. The controller demonstrated a fast response promoting the heat input necessary to maintain the set welding temperature. The results demonstrated that temperature control using the TWT method is suitable to achieve higher joint performance and provides a fast setup of optimal parameters for different environments. © 2019, Universidade Federal de Uberlandia. All rights reserved.

  • 25.
    Ferreira Magalhães, Ana Catarina
    et al.
    University West, Department of Engineering Science, Division of Welding Technology.
    De Backer, Jeroen
    University West, Department of Engineering Science, Division of Production Systems. TWI Ltd. Cambridge, UK.
    Martin, Jonathan Peter
    TWI Ltd. Cambridge, UK.
    Bolmsjö, Gunnar
    Linnaeus University, Växjö, Sweden.
    In-situ temperature measurement in friction stir welding of thick section aluminium alloys2019In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 39, p. 12-17Article in journal (Refereed)
    Abstract [en]

    Friction stir welding (FSW) is a reliable joining technology with a wide industrial uptake. However, several fundamentals of the process such as the temperature inside the stirred zone of the weld and its influence on mechanical properties, are not yet fully understood. This paper shows a method for accurate temperature measurements in multiple locations around the tool, to identify the location of the peak temperature, the temperature variations between the advancing and the retreating side of the tool and its relation to the tool geometry. Both standardised thermocouples in the FSW tool and the novel "tool-workpiece thermocouple" method were used to record temperatures.Bead-on-plate welds in 20 mm thickness AA6082-T6 were produced while the temperatures were measured in three locations on the FSW tool: at the shoulder outer diameter, at the transition from shoulder to probe and at the probe tip. It was found that the hottest point in the stirred zone was 607 °C and was located at the transition between the shoulder and probe, on the retreating-trailing side of the tool. The lowest temperature was found at the probe tip on the retreating-leading side of the tool.The results offer a better understanding of the temperature distribution around a FSW tool. The method presented can be applied to verification of thermal simulation models, tool design optimization, quality assurance and temperature feedback control.

  • 26.
    Filipiak, David
    University West, Department of Engineering Science, Division of Production Systems.
    Deposition of Alloy 718 using robotized laser metal wire deposition2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aerospace industry wishes to investigate the possibilities of additive manufacturing (AM) processes to produce parts with improved design flexibility in cost-effective and environmentally friendly ways, serving as a complement to today's conventional manufacturing methods. MERLIN is an EU-funded research project constituting of University West and GKN Aerospace Sweden AB among others, with focus on developing AM for productivity improvements, monitoring and control techniques as well as thermal management strategies.

    The aim of this thesis work was to investigate the possibilities to build up a defined deposit geometry of Alloy 718 filler material onto flat Alloy 718 substrate plates by using the robotized laser metal wire deposition (rLMD-w) process. Alloy 718 belongs to the superalloys, a metal group that have been commonly used in aircraft engine and gas turbine applications due to their excellent material properties at elevated temperatures. The focus of the thesis was directed towards investigating the process stability and deposited material quality. A set of iterative experimental process trials combined with metallographic evaluations were conducted at the facilities of Production Technology Centre (PTC), in close collaboration with GKN Aerospace Sweden AB.

    The results revealed that both the deposition process and the microstructure are favored by maintaining a low delta-temperature throughout the welding build-up. Two thermal management strategies were applied, with their combined use showing to have the most beneficial outcome to the deposit quality. The delta-temperature effect is believed to have connections to hot cracking mechanisms and the relative cracking susceptibility of superalloys.

    The work conducted within this thesis was not able to succeed in building a deposit completely free from material defects. The final experiment geometry was however greatly improved regarding smooth and repeatable material transfer, with only minor online adjustments being necessary by the operator. The material defects in the form of lack of fusion and cracks were also immensely decreased in both size and quantity, compared to initial trials. The last deposit built, incorporating both thermal management strategies, resulted in no lack of fusion defects and only one micro-sized crack of 363 μm found between the top two layers of the geometry (layer 9 and 10).

  • 27.
    Gaudiuso, Caterina
    et al.
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, Via Amendola 173, Bari, Italy.
    Giannuzzi, Giuseppe
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, Via Amendola 173, Bari, Italy.
    Choquet, Isabelle
    University West, Department of Engineering Science, Division of Welding Technology.
    Lugarà, Pietro Mario
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, Via Amendola 173, Bari, Italy.
    Ancona, Antonio
    University West, Department of Engineering Science, Division of Production Systems.
    Incubation effect in burst mode fs-laser ablation of stainless steel samples2018In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 10520, article id 105200AArticle in journal (Refereed)
    Abstract [en]

    We report on an experimental study of the incubation effect during irradiation of stainless steel targets with bursts of femtosecond laser pulses at 1030 nm wavelength and 100 kHz repetition rate. The bursts were generated by splitting the pristine 650-fs laser pulses using an array of birefringent crystals which provided time separations between sub-pulses in the range from 1.5 ps to 24 ps. We measured the threshold fluence in Burst Mode, finding that it strongly depends on the bursts features. The comparison with Normal Pulse Mode revealed that the existing models introduced to explain the incubation effect during irradiation with trains of undivided pulses has to be adapted to describe incubation during Burst Mode processing. In fact, those models assume that the threshold fluence has a unique value for each number of impinging pulses in NPM, while in case of BM we observed different values of threshold fluence for fixed amount of sub-pulses but different pulse splitting. Therefore, the incubation factor coefficient depends on the burst features. It was found that incubation effect is higher in BM than NPM and that it increases with the number of sub-pulses and for shorter time delays within the burst. Two-Temperature-Model simulations in case of single pulses and bursts of up to 4 sub-pulses were performed to understand the experimental results. © Copyright SPIE.

  • 28.
    Gaudiuso, Caterina
    et al.
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, via Amendola 173, Bari, Italy & Università degli Studi di Bari, Dipartimento Interuniversitario di Fisica, via Amendola 173, Bari, Italy .
    Giannuzzi, Giuseppe
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, via Amendola 173, Bari, Italy & Università degli Studi di Bari, Dipartimento Interuniversitario di Fisica, via Amendola 173, Bari, Italy.
    Volpe, Annalisa
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, via Amendola 173, Bari, Italy.
    Lugarà, Pietro Mario
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, via Amendola 173, Bari, Italy & Università degli Studi di Bari, Dipartimento Interuniversitario di Fisica, via Amendola 173, Bari, Italy.
    Choquet, Isabelle
    University West, Department of Engineering Science, Division of Welding Technology.
    Ancona, Antonio
    University West, Department of Engineering Science, Division of Production Systems. Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, via Amendola 173, Bari, Italy.
    Incubation during laser ablation with bursts of femtosecond pulses with picosecond delays2018In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, no 4, p. 3801-3813Article in journal (Refereed)
    Abstract [en]

    Abstract: We report on an experimental investigation of the incubation effect during irradiation of stainless steel with bursts of ultrashort laser pulses. A series of birefringent crystals was used to split the pristine 650-fs pulses into bursts of up to 32 sub-pulses with time separations of 1.5 ps and 3 ps, respectively. The number of selected bursts was varied between 50 and 1600. The threshold fluence was measured in case of Burst Mode (BM) processing depending on the burst features, i.e. the number of sub-pulses and their separation time, and on the number of bursts. We found as many values of threshold fluence as the combinations of the number of bursts and of sub-pulses constituting the bursts set to give the same total number of impinging sub-pulses. However, existing incubation models developed for Normal Pulse Mode (NPM) return, for a given number of impinging pulses, a constant value of threshold fluence. Therefore, a dependence of the incubation coefficient with the burst features was hypothesized and experimentally investigated. Numerical solutions of the Two Temperature Model (TTM) in case of irradiation with single bursts of up to 4 sub-pulses have been performed to interpret the experimental results. © 2018 Optical Society of America.

  • 29.
    Glorieux, Emile
    University West, Department of Engineering Science, Division of Production Systems.
    Multi-Robot Motion Planning Optimisation for Handling Sheet Metal Parts2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Motion planning for robot operations is concerned with path planning and trajectory generation. In multi-robot systems, i.e. with multiple robots operating simultaneously in a shared workspace, the motion planning also needs to coordinate the robots' motions to avoid collisions between them. The multi-robot coordination decides the cycle-time for the planned paths and trajectories since it determines to which extend the operations can take place simultaneously without colliding. To obtain the quickest cycle-time, there needs to bean optimal balance between, on the one hand short paths and fast trajectories, and on the other hand possibly longer paths and slower trajectories to allow that the operations take place simultaneously in the shared workspace. Due to the inter-dependencies, it becomes necessary to consider the path planning, trajectory generation and multi-robot coordination together as one optimisation problem in order to find this optimal balance.This thesis focusses on optimising the motion planning for multi-robot material handling systems of sheet metal parts. A methodology to model the relevant aspects of this motion planning problem together as one multi-disciplinary optimisation problem for Simulation based Optimisation (SBO) is proposed. The identified relevant aspects include path planning,trajectory generation, multi-robot coordination, collision-avoidance, motion smoothness, end-effectors' holding force, cycle-time, robot wear, energy efficiency, part deformations, induced stresses in the part, and end-effectors' design. The cycle-time is not always the (only) objective since it is sometimes equally/more important to minimise robot wear, energy consumption, and/or part deformations. Different scenarios for these other objectives are therefore also investigated. Specialised single- and multi-objective algorithms are proposed for optimising the motion planning of these multi-robot systems. This thesis also investigates how to optimise the velocity and acceleration profiles of the coordinated trajectories for multi-robot material handling of sheet metal parts. Another modelling methodology is proposed that is based on a novel mathematical model that parametrises the velocity and acceleration profiles of the trajectories, while including the relevant aspects of the motion planning problem excluding the path planning since the paths are now predefined.This enables generating optimised trajectories that have tailored velocity and acceleration profiles for the specific material handling operations in order to minimise the cycle-time,energy consumption, or deformations of the handled parts.The proposed methodologies are evaluated in different scenarios. This is done for real world industrial case studies that consider the multi-robot material handling of a multi-stage tandem sheet metal press line, which is used in the automotive industry to produce the cars' body panels. The optimisation results show that significant improvements can be obtained compared to the current industrial practice.

  • 30.
    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. University West, Department of Engineering Science, Division of Production 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.

  • 31.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Franciosa, Pasquale
    University of Warwick, Warwick Manufacturing Group, CV4 7AL Coventry, UK.
    Ceglarek, Darek
    Warwick Manufacturing Group, University of Warwick, CV4 7AL Coventry, UK.
    End-effector design optimisation and multi-robot motion planning for handling compliant parts2018In: Structural and multidisciplinary optimization (Print), ISSN 1615-147X, E-ISSN 1615-1488, Vol. 57, no 3, p. 1377-1390Article in journal (Refereed)
    Abstract [en]

    The deformation of compliant parts during material handling is a critical issue that can significantly affect the productivity and the parts' dimensional quality. There are multiple relevant aspects to consider when designing end-effectors to handle compliant parts, e.g. motion planning, holding force, part deformations, collisions, etc. This paper focuses on multi-robot material handling systems where the end-effector designs influence the coordination of the robots to prevent that these collide in the shared workspace. A multi-disciplinary methodology for end-effector design optimisation and multi-robot motion planning for material handling of compliant parts is proposed. The novelty is the co-adaptive optimisation of the end-effectors' structure with the robot motion planning to obtain the highest productivity and to avoid excessive part deformations. Based on FEA, the dynamic deformations of the parts are modelled in order to consider these during the collision avoidance between the handled parts and obstacles. The proposed methodology is evaluated for a case study that considers the multi-robot material handling of sheet metal parts in a multi-stage tandem press line. The results show that a substantial improvement in productivity can be achieved (up to 1.9%). These also demonstrate the need and contribution of the proposed methodology.

  • 32.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Franciosa, Pasquale
    University of Warwick, Warwick Manufacturing Group (WMG), Coventry, CV4 7AL, United Kingdom.
    Ceglarek, Dariusz
    University of Warwick, Warwick Manufacturing Group (WMG), Coventry, CV4 7AL, United Kingdom.
    Quality and productivity driven trajectory optimisation for robotic handling of compliant sheet metal parts in multi-press stamping lines2019In: Robotics and Computer-Integrated Manufacturing, ISSN 0736-5845, E-ISSN 1879-2537, Vol. 56, p. 264-275Article in journal (Refereed)
    Abstract [en]

    This paper investigates trajectory generation for multi-robot systems that handle compliant parts in order to minimise deformations during handling, which is important to reduce the risk of affecting the part’s dimensional quality. An optimisation methodology is proposed to generate deformation-minimal multi-robot coordinated trajectories for predefined robot paths and cycle-time. The novelty of the proposed optimisation methodology is that it efficiently estimates part deformations using a precomputed Response Surface Model (RSM), which is based on data samples generated by Finite Element Analysis (FEA) of the handled part and end-effector. The end-effector holding forces, plastic part deformations, collision-avoidance and multi-robot coordination are also considered as constraints in the optimisation model. The optimised trajectories are experimentally validated and the results show that the proposed optimisation methodology is able to significantly reduce the deformations of the part during handling, i.e. up to 12% with the same cycle-time in the case study that involves handling compliant sheet metal parts. This investigation provides insights into generating specialised trajectories for material handling of compliant parts that can systematically minimise part deformations to ensure final dimensional quality. © 2018

  • 33.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Parthasarathy, Prithwick
    University West, Department of Engineering Science, Division of Production Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Production Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    Energy Consumption Model for 2D-Belt Robots2016In: 7th Swedish Production Symposium Conference proceedings, Lund: SPS16 , 2016, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Production that incorporates robotics consumes energy and the trend today is to reduce consumed energy not only to lower the cost but also to be a more energy efficient entity. Energy models can be used to predict the energy consumed by robot(s) for optimising the input parameters which determine robot motion and task execution. This paper presents an energy model to predict the energy consumption of 2D-belt robots used for press line tending. Based on the components’ specifications and the trajectory, an estimation of the energy consumption is computed. The capabilities of the proposed energy model to predict the energy consumption during the planning-phase (i.e. before installation), avoiding the need for physical experiments, are demonstrated. This includes predicting potential energy reductions achieved by reducing the weight of the gripper tools. Additionally, it is also shown how to investigate the energy saving achieved by using mechanical brakes when the robot is idle. This effectively illustrates the purpose and usefulness of the proposed energy model.

  • 34.
    Glorieux, Emile
    et al.
    WMG, University of Warwick, Coventry, CV4 7AL, United Kingdom.
    Parthasarathy, Prithwick
    ISolve Technologies, Chennai, 600018, India.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Production Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    Energy model for motion planning of 2D-belt press line tending robots2020In: International Journal of Manufacturing Research, ISSN 1750-0591, Vol. 15, no 1, p. 52-72Article in journal (Refereed)
    Abstract [en]

    A current trend in production is to reduce energy consumption where possible not only to lower the cost but also to be a more energy efficient entity. This paper presents an energy model to estimate the electrical energy consumption of 2D-belt robots used for material handling in multi-stage sheet metal press lines. An estimation of the energy consumption is computed by the proposed energy model based on the robot components’ specifications, the robot path and trajectory. The proposed model can predict the energy consumption offline by simulation, and thus, before installation, avoiding the need for physical experiments. It is demonstrated that it can be used for predicting potential energy reductions achieved by optimising the motion planning. Additionally, it is also shown how to investigate the energy saving achieved by using mechanical brakes when the robot is idle. This effectively illustrates the usefulness of the proposed energy model. © 2020 Inderscience Enterprises Ltd.

  • 35.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Riazi, Sarmad
    Department of Signals and Systems, Chalmers University of Technology, S-412 96 Gothenburg, Sweden.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Production Systems. Department of Signals and Systems, Chalmers University of Technology, S-412 96 Gothenburg, Sweden.
    Productivity/energy optimisation of trajectories and coordination for cyclic multi-robot systems2018In: Robotics and Computer-Integrated Manufacturing, ISSN 0736-5845, E-ISSN 1879-2537, Vol. 49, p. 152-161Article in journal (Refereed)
    Abstract [en]

    The coordination of cyclic multi-robot systems is a critical issue to avoid collisions but also to obtain the shortest cycle-time. This paper presents a novel methodology for trajectory and coordination optimisation of cyclic multi-robot systems. Both velocity tuning and time delays are used to coordinate the robots that operate in close proximity and avoid collisions. The novel element is the non-linear programming optimisation model that directly co-adjusts the multi-robot coordination during the trajectory optimisation, which allows optimising these as one problem. The methodology is demonstrated for productivity/smoothness optimisation, and for energy efficiency optimisation. An experimental validation is done for a real-world case study that considers the multi-robot material handling system of a multi-stage tandem press line. The results show that the productivity optimisation with the methodology is competitive compared to previous research and that substantial improvements can be achieved, e.g. up to 50% smoother trajectories and 14% reduction in energy consumption for the same productivity. This paper addresses the current lack of systematic methodologies for generating optimal coordinated trajectories for cyclic multi-robot systems to improve the productivity, smoothness, and energy efficiency.

  • 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 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. University West, Department of Engineering Science, Division of Production Systems. 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.

  • 37.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Production Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Production Systems. Department of Signals and Systems, Chalmers University of Technology, S-412 96 Gothenburg, Sweden.
    Constructive cooperative coevolution for large-scale global optimisation2017In: Journal of Heuristics, ISSN 1381-1231, E-ISSN 1572-9397, Vol. 23, no 6, p. 449-469Article in journal (Refereed)
    Abstract [en]

    This paper presents the Constructive Cooperative Coevolutionary ( C3C3 ) algorithm, applied to continuous large-scale global optimisation problems. The novelty of C3C3 is that it utilises a multi-start architecture and incorporates the Cooperative Coevolutionary algorithm. The considered optimisation problem is decomposed into subproblems. An embedded optimisation algorithm optimises the subproblems separately while exchanging information to co-adapt the solutions for the subproblems. Further, C3C3 includes a novel constructive heuristic that generates different feasible solutions for the entire problem and thereby expedites the search. In this work, two different versions of C3C3 are evaluated on high-dimensional benchmark problems, including the CEC'2013 test suite for large-scale global optimisation. C3C3 is compared with several state-of-the-art algorithms, which shows that C3C3 is among the most competitive algorithms. C3C3 outperforms the other algorithms for most partially separable functions and overlapping functions. This shows that C3C3 is an effective algorithm for large-scale global optimisation. This paper demonstrates the enhanced performance by using constructive heuristics for generating initial feasible solutions for Cooperative Coevolutionary algorithms in a multi-start framework.

  • 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. University West, Department of Engineering Science, Division of Production 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, IEEE, 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.

  • 39.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Production Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Production Systems. Department of Signals and Systems, Chalmers University of Technology,Gothenburg, Sweden.
    Multi-objective constructive cooperative coevolutionary optimization of robotic press-line tending2017In: Engineering optimization (Print), ISSN 0305-215X, E-ISSN 1029-0273, Vol. 49, no 10, p. 1685-1703Article in journal (Refereed)
    Abstract [en]

    This article investigates multi-objective optimization of the robot trajectories and position-based operation-coordination of complex multi-robot systems, such as press lines, to improve the production rate and obtaining smooth motions to avoid excessive wear of the robots’ components. Different functions for handling the multiple objectives are evaluated on realworld press lines, including both scalarizing single-objective functions and Pareto-based multi-objective functions. Additionally, the Multi-Objective Constructive Cooperative Coevolutionary (moC3) algorithm is proposed, for Pareto-based optimization, which uses a novel constructive initialization of the subpopulations in a co-adaptive fashion. It was found that Paretobased optimization performs better than the scalarizing single-objective functions. Furthermore, moC3 gives substantially better results compared to manual online tuning, as currently used in the industry. Optimizing robot trajectories and operation-coordination of complex multi-robot systems using the proposed method with moC3 significantly improves productivity and reduces maintenance. This article hereby addresses the lack of systematic methods for effectively improving the productivity of press lines.

  • 40.
    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. University West, Department of Engineering Science, Division of Production Systems. 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.

  • 41.
    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. University West, Department of Engineering Science, Division of Production 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.

  • 42.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Production Systems.
    Parthasarathy, Prithwick
    University West, Department of Engineering Science, Division of Production Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Production Systems.
    An energy model for press line tending robots2016In: ESM'2016, the 2016 European simulation and Modelling Conference: Modelling and Simulation '2016 / [ed] José Evora-Gomez & José Juan Hernandez-Cabrera, Eurosis , 2016, p. 377-383Conference paper (Refereed)
    Abstract [en]

    Today most industries aim at reducing energy consumption to become sustainable and environment-friendly. The automotive industry, with mass production and large volumes, is one such example. With many robots working round the clock, there is great potential to save energy. In this climate there is a need for robot simulation models that can be used for motion and task execution optimisation and which are aimed lowering energy consumption. This paper presents an energy consumption model for 2D-belt robots for press line tending in the automotive sector. The energy model is generic for 2D-belt robots and is entirely based on component specifications (e.g., dimensions, masses, inertia). An implementation and validation against a real 2D-belt tending robot used in the automotive industry is performed and presented. The purpose and usefulness of the energy model is also demonstrated by two application cases; the investigation of potential energy reductions achieved by reducing the weight of gripper tools, and by using mechanical brakes when the robot is idle.

  • 43.
    Gupta, Siddhartha
    et al.
    VIT Vellore,School Of Electrical Engineering (SELECT),Vellore,India.
    Sinha, Neha
    VIT Vellore,School Of Electrical Engineering (SELECT),Vellore,India.
    Ramasamy, Sudha
    University West, Department of Engineering Science, Division of Production Systems.
    Babu, Challa
    VIT Vellore,School Of Electrical Engineering (SELECT),Vellore,India.
    Breast Cancer Detection Using Image Processing Techniques2019In: 2019 Innovations in Power and Advanced Computing Technologies (i-PACT), Institute of Electrical and Electronics Engineers Inc. , 2019, Vol. 1Conference paper (Refereed)
    Abstract [en]

    Cancer is the uncontrolled multiplication of group of cells in a particular location of the body and is the second largest disease leading to the death of women in the world. The disease can be cured if it is detected in early stages. A lot of research has been done to find out the tumor correctly but a 100% accurate method has not been found. Research on breast cancer detection using digital image processing is not new but many new approaches in this field is being considered to accurately predict the tumor region. The present approach is to detect the tumor region visually as well as to figure out in which region the tumor is mostly concentrated. This work majorly focuses on finding out the best algorithm/s to detect the tumor present in the breast. In the proposed work, a variety of algorithms has been applied but the best one suited for cancer detection is the combination of K Means, Closing, Dilation and Canny Edge Detection algorithm. © 2019 IEEE.

  • 44.
    Gustavsson Christiernin, Linn
    University West, Department of Engineering Science, Division of Production System.
    How to describe interaction with a collaborative robot2017In: HRI '17 Proceedings of the Companion of the 2017 ACM/IEEE International Conference on Human-Robot Interaction, 2017, p. 93-94Conference paper (Refereed)
    Abstract [en]

    In this paper, we describe early work on a classification model on how to interact with industrial and other types of robots. We suggest a classification for how to describe different scenarios within Human-Robot Interaction. The idea with this model is to help when identifying the gap between where a company is and where they would like to be when it comes to collaborative automation. © 2017 Author.

  • 45.
    Gustavsson Christiernin, Linn
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Augustsson, Svante
    University West, Department of Engineering Science, Division of Production Systems.
    Interacting with Industrial Robots: A Motion-based Interface2016In: AVI '16 Proceedings of the International Working Conference on Advanced Visual Interfaces / [ed] Paolo Buono, Rosa Lanzilotti, Maristella Matera, New York: ACM Digital Library, 2016, p. 310-311Conference paper (Refereed)
    Abstract [en]

    Collaborative industrial robot cells are becoming more and more interesting for industry through the new Industrie 4.0 initiative. In this paper we report early work on motion-based interaction with industrial robots. Human motion is tracked by a Kinect camera and translated into robot code. A group of tests subjects are asked to interact with the system and their activities are observed. Lessons learned on interaction challenges in a robot cell are reported.

  • 46.
    Gustavsson Christiernin, Linn
    et al.
    University West, Department of Engineering Science, Division of Production Systems.
    Hartler, Johan
    Department of Shipping and Marine Technology Chalmers Technical University Gothenburg, Sweden.
    Multi-Layered Design and Game-Based Learning as a Pedagogical Concept: How to develop proper behavior in ARPA simulator training2016Conference paper (Refereed)
    Abstract [en]

    To become a professional master mariner one has to develop many different skills and have an understanding of how to act in different situations on the bridge. Within the master mariner program at Chalmers University of Technology, Sweden, simulation technologies are used to evolve pertinent skills within the educational program. A challenge with using a full scale simulator from the outset of the program is to get the students to develop both professional competencies and internalize tacit knowledge in the navigation of a ship when the interface of the simulator itself is quite demanding. By using an adaptive Multi-Layered Design approach in combination with game based learning, this paper proposes how to guide the student through a more summative learning process. The main idea is to grant limited access to what the students can do with some functions, and gradually turn on more functionality in order to develop certain experienced behaviors to get them to understand the logical approach behind selections and to make them think through why and when they should do things.

  • 47.
    Hagqvist, Petter
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Heralic, Almir
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Technology, Mathematics and Computer Science, Division for Electrical Engineering and Land Surveying.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Manufacturing Processes. University West, Department of Engineering Science, Division of Production Systems. Chalmers.
    Resistance based iterative learning control of additive manufacturing with wire2015In: Mechatronics (Oxford), ISSN 0957-4158, E-ISSN 1873-4006, Vol. 31, p. 116-123Article in journal (Refereed)
    Abstract [en]

    This paper presents successful feed forward control of additive manufacturing of fully dense metallic components. The study is a refinement of former control solutions of the process, providing more robust and industrially acceptable measurement techniques. The system uses a solid state laser that melts metal wire, which in turn is deposited and solidified to build the desired solid feature on a substrate. The process is inherently subjected to disturbances that might hinder consecutive layers to be deposited appropriately. The control action is a modified wire feed rate depending on the surface of the deposited former layer, in this case measured as a resistance. The resistance of the wire stick-out and the weld pool has shown to give an accurate measure of the process stability, and a solution is proposed on how to measure it. By controlling the wire feed rate based on the resistance measure, the next layer surface can be made more even. A second order iterative learning control algorithm is used for determining the wire feed rate, and the solution is implemented and validated in an industrial setting for building a single bead wall in titanium alloy. A comparison is made between a controlled and an uncontrolled situation when a relevant disturbance is introduced throughout all layers. The controller proves to successfully mitigate these disturbances and maintain stable deposition while the uncontrolled deposition fails.

  • 48.
    Hattinger, Monika
    University West, Department of Engineering Science, Division of Production System.
    Co-constructing Expertise: Competence Development through Work-Integrated e-Learning in joint Industry-University Collaboration2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is inter-disciplinary and proceed from the ongoing challenges of the increased digitalization, automation and robotization that impact the manufacturing industry's emergent need of high-qualified practitioners. Digitalization also challenges universities to open up to external collaboration and to design blended e-learning targeting industry knowledge needs. The studies take up on such challenges and explore inter-organizational collaborations and forms of knowledge construction to strengthen engineering competences integrated inwork in a way that enables manufacturing companies to remain effective and to be prepared for future industrial transformations. The objective is to explore how mutual construction of knowledge emerge through learning activities between multiple actors in a joint industry-university collaborative e-learning practice. The empirical setting is a new type of collaborative course concept developed within the project ProdEx. The project comprise a network of industries and one university in a longitudinal design and implementation process of blended and work-integrated e-learning. This initiative was explored with a collaborative action research approach integrated with five studies, from four perspectives, the industry managers, the practitioners, the research teachers and the course unit. Negotiated knotworking, from cultural-historical activity theory, became a central theoretical concept and a working tool to examine how managers, practitioners and research teachers together negotiated production technology knowledge content and e-learning design towards future workplace transformations. This concept was used to further understand how co-construction of knowledge was developing over time into a richer concept. The results contributes to a wider understanding of how co-construction of knowledge in an e-learning design practice was developing into stronger relations between actors and into more stable courses. Real learning cases and digital labs support theory-practical intertwining of mutual learning of active participation between practitioners and ix research teachers. Initial e-learning technology failures and pedagogical mistakes in the courses were easier to overcome, than issues concerning continuous company support for course participation. Matching industry competence needs with university research fields is continuously challenging. Practitioners' aiming for personal continuous competence development on university level created critical and high-qualitative performances and valuable engagement throughout the process of co-construction of knowledge. The knowledge co-construction became a two-way development, pushing research teachers to active involve and consider practitioners' industry experiences concerning learning content, pedagogical strategies and e-learning forms. While earlier research has discussed the problems of crossing boundaries between industry and university, overall findings show that industry and university actors are crossing boundaries when they mutually co-construct knowledge in an elearningpractice. Co-construction of knowledge entail mutual trust, sideways and interactive learning in a collaborative context. The main contribution suggested in the thesis is that co-constructing expertise entail three levels of activities among actors; to have insight into the purposes and practices of others (relational expertise), the capacity to transform the problems of a practice and together build common knowledge (distributed expertise), and finally the capacity of mutually co-construct knowledge acted upon in practice towards work-integrated transformations (co-constructing expertise).

  • 49.
    Hattinger, Monika
    University West, Department of Engineering Science, Division of Production Systems.
    Researchers design conceptions of e-learning courses targeting industry practitioners’ competence needs2018In: International Journal of Continuing Engineering Education and Life-Long Learning, ISSN 1560-4624, E-ISSN 1741-5055, Vol. 28, no 3-4, p. 235-253Article in journal (Refereed)
    Abstract [en]

    This paper addresses two overall challenges that concern university research teachers' professional identities when they make design plans for blended e-learning courses targeting practitioners' competence needs. Research teachers' are challenged by finding applicable learning material that matches practitioners' experiences and workplace knowledge demands. They are also challenged when they need to digitise engineering learning content such as virtual labs, and machine-related cases such as turning and milling aligning to workplace needs. Design plans used for campus education is argued to be insufficient meeting these challenges. Consequently, researchers' professional identities become vulnerable when they cross boundaries between university and industry practices. Results show that even if researchers are not trained for educational e-learning design they identify concepts for digitising cases and labs. By applying a work-integrated learning strategy, the courses integrate practical and theoretical tasks and cases collected from the manufacturing industry workplaces and thereby support competence development. © 2018 Inderscience Enterprises Ltd.

  • 50.
    Hattinger, Monika
    University West, Department of Engineering Science, Division of Production System.
    Sociomateriality and design – How do we un-pack technology for knowing in practice?: Research in Progress/Workshop2016Conference paper (Other academic)
    Abstract [en]

    Blended e-learning permeates flexibility and school is no longer the only place for learning, rather through e-learning courses new ways of building competences throughout life and integrated in the workplace can be accomplished. Technological artifacts, the material itself do not create learning,rather, social and pedagogical aspects from a participatory perspective in e-learning courses is needed to balance the impact of technology. Challenges to reach balance between material and social is in this paper illustrated as a sociomaterial learning practice through a work-integrated e-learning (e-WIL) project between a university and collaborating manufacturing industries. This learning practice comprise design of e-learning courses, target industry knowledge needs to reach for being a competent employee. Teachers' and course participants' activities show various challenges of work integrated e-learning. Early results from focus group sessions and observations are categorized as knowing-how to design and use digital learning technology, knowing-what knowledge to be learnt for work practice and knowing-when to use new knowledge in work practice.

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