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  • 51.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Thermoelectric method for temperature measurement in friction stir welding2013In: Science and technology of welding and joining, ISSN 1362-1718, E-ISSN 1743-2936, Vol. 18, no 7, p. 541-550Article in journal (Refereed)
    Abstract [en]

    Previous research within friction stir welding (FSW) has demonstrated that online control of welding parameters can improve the mechanical properties and is necessary for certain applications to guarantee a consistent weld quality. One approach to control the process is by adapting the heat input to maintain a stable welding temperature, within the specified operating boundaries. This requires accurate in-process temperature measurements. This paper presents a novel method to measure the temperature at the interface of the FSW tool and workpiece. The method is based on the thermoelectric effect between dissimilar materials. The measurements are compared to thermocouple measurements and to a physical model and show good correspondence to each other. Experiments demonstrate that the method can quickly detect temperature variations, due to geometrical variations of the workpiece or due to parameter changes. This allows use of the method for online control of robotic FSW.

  • 52.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Temperature control of robotic friction stir welding using the thermoelectric effect2014In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 70, no 1-4, p. 375-383Article in journal (Refereed)
    Abstract [en]

    Friction stir welding (FSW) of non-linear joints receives an increasing interest from several industrial sectors like automotive, urban transport and aerospace. A force-controlled robot is particularly suitable for welding complex geometries in lightweight alloys. However, complex geometries including three-dimensional joints, non-constant thicknesses and heat sinks such as clamps cause varying heat dissipation in the welded product. This will lead to changes in the process temperature and hence an unstable FSW process with varying mechanical properties. Furthermore, overheating can lead to a meltdown, causing the tool to sink down into the workpiece. This paper describes a temperature controller that modifies the spindle speed to maintain a constant welding temperature. A newly developed temperature measurement method is used which is able to measure the average tool temperature without the need for thermocouples inside the tool. The method is used to control both the plunging and welding operation. The developments presented here are applied to a robotic FSW system and can be directly implemented in a production setting.

  • 53.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation Systems.
    Surface Quality and Strength in Robotic Friction Stir Welding of Thin Automotive Aluminium Alloys2011In: The 4th International Swedish Production Symposium / [ed] Jan-Eric Ståhl, The Swedish Production Academy , 2011, p. 554-562Conference paper (Refereed)
    Abstract [en]

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

  • 54.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Process and Product Development.
    Oqueka, Jens
    University West, Department of Engineering Science.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Investigation of path compensation methods for robotic friction stir welding2012In: Industrial robot, ISSN 0143-991X, E-ISSN 1758-5791, Vol. 39, no 6, p. 601-608Article in journal (Refereed)
    Abstract [en]

    Purpose – Friction stir welding (FSW) is a novel method for joining materials without using consumables and without melting the materials. The purpose of this paper is to present the state of the art in robotic FSW and outline important steps for its implementation in industry and specifically the automotive industry.

    Design/methodology/approach – This study focuses on the robot deflections during FSW, by relating process forces to the deviations from the programmed robot path and to the strength of the obtained joint. A robot adapted for the FSW process has been used in the experimental study. Two sensor-based methods are implemented to determine path deviations during test runs and the resulting welds were examined with respect to tensile strength and path deviation.

    Findings – It can be concluded that deflections must be compensated for in high strengths alloys. Several strategies can be applied including online sensing or compensation of the deflection in the robot program. The welding process was proven to be insensitive for small deviations and the presented path compensation methods are sufficient to obtain a strong and defect-free welding joint.

    Originality/value – This paper demonstrates the effect of FSW process forces on the robot, which is not found in literature. This is expected to contribute to the use of robots for FSW. The experiments were performed in a demonstrator facility which clearly showed the possibility of applying robotic FSW as a flexible industrial manufacturing process.

  • 55.
    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)
  • 56.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Soron, Mikael
    ESAB Welding AB .
    Three-dimensional friction stir welding of Iconel 718 using the ESAB Rosio FSW-robot2013In: Trends in Welding Research: Proceedings of the International Conference on Trends in Welding Research, June 4-8, 2012, Hilton Chicago/Indian Lakes ResortChicago, Illinois, USA / [ed] Tarasankar DebRoy, Stan A. David, John N. DuPont, Toshihiko Koseki, Harry K. Bhadeshia, Ohio: ASM International, 2013, p. 829-833Conference paper (Refereed)
    Abstract [en]

    Robotic Friction Stir Welding (FSW) facilitates for increased welding flexibility, and allows for studies of forces in three dimensions without having the high cost of a stiff 5-axes FSW machine. Recent developments in tool materials and welding equipment motivate this study on FSW of high-strength alloys by a robot in a three dimensional workspace. New concepts of aircraft engines suggest higher temperatures to increase engine efficiency, requiring more durable materials such as the nickel-based alloy 718. The ESAB Rosio (TM) FSW robot, used in this study, can deliver up to 15kN downforce and 90Nm torque. This is sufficient for welding high-strength alloys of limited thickness. This study focuses on the process forces during friction stir welding of Inconel 718 with thickness up to 3mm in butt-joint configuration. A newly developed threaded Poly-Crystalline Boron Nitride (PCBN) tool with convex shoulder is used in a local argon-shielded atmosphere. Initial tests are performed in a stiff FSW machine in position controlled mode. The measured process forces in position control are later on used as parameters on the force-controlled robot. Different backing bar materials are investigated with the aim to decrease the risk of root defects. Tool steel and regular inconel backing bars are proven to be too soft for this purpose and alternatives are suggested. The optimal welding parameters are tuned to combine a good weld quality with the process forces that can be obtained by the robot. Preheating is used to further decrease the need of high process forces.

  • 57.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Soron, Mikael
    ESAB Welding AB .
    Cederqvist, Lars
    Influence of side-tilt angle on process forces and lap joint strength in robotic friction stir welding2012In: Proceedings 9th International friction stir welding symposium, Huntsville, AL, USA, 15th to 17th of May 2012, 2012, p. CD-Conference paper (Refereed)
  • 58.
    Delcorte, Kilian
    University West, Department of Engineering Science.
    Indoor localization for moving elements on stage within the context of entertainment industry2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis explored the most appropriate technology for indoor positioning of automated stage elements within the entertainment industry context. A range of technologies were evaluated, such as camera systems, Bluetooth, GPS, and more. The study primarily focused on the Ultra-Wideband (UWB) Real Time Location System (RTLS) due to its evident potential.

    A comprehensive analysis was conducted to understand the basic mechanics of UWB technology, its comparative advantages, and possible limitations. Practical application of UWB RTLS for static positioning was assessed through experiments within a small-scale setup. These experiments examined crucial factors such as system calibration, noise reduction, signal processing, and accuracy measurement. These tests helped identify challenges and potential solutions for effective implementation of UWB RTLS in such settings

    Subsequently, to further test the technology in a real-world context, field tests were executed in a full-scale stage setup. These tests aimed to mimic the conditions of a live performance environment and provided insights into the challenges and potential solutions for successful implementation of UWB RTLS in larger environment and more complex setting. 

    Results from the experiments conducted in this thesis revealed an accuracy of approximately 30cm in position and 3 degrees in rotation using a complete real-sized Ultra-Wideband system. The precision achieved in these measurements was notably high. 

    These results indicate that the UWB has the potential to greatly enhance the operation of the wagon system, allowing for reliable position retrieval when needed. The accuracy achieved, although slightly below theoretical expectations, is still considered very good and provides a solid foundation for further improvements in the system.

    The thesis concludes with a discussion on the potential future developments of UWB technology within the entertainment industry. Furthermore, it touches upon other fields that could potentially benefit from the application of precise indoor positioning. The work done in this thesis lays a solid foundation for future research and development in the applicationof UWB technology in entertainment and beyond.

  • 59.
    Denys, Kristof
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Circular motion for robotized metal deposition: verification and implementation2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Metal deposition is an additive layered manufacturing process that deposits molten metal droplets on a substrate and by repeating this process layer by layer, a complex shaped 3D geometry can be manufactured.

    In this thesis, the metal deposition process is performed by a robot with a wire feeder tool and a laser as energy source to melt the metal wire. The robot programming for robotized metal deposition process can be completely automated by computer aided robotics software. University West is currently developing an add-in application in a computer aided robotics software, Process Simulate, that is capable of programming the robotized metal deposition process.

    The first goal of this thesis was to verify the up to now developed software and the process from CAD drawing down to robot code. Another goal was to find and implement an algorithm that will reduce the number of locations on a circular arc to three locations.

    The algorithm to minimize the locations must be capable of changing all the different curvature paths to linear and circular arc motions which are easy to translate to robot code. The user should be able to decide the fitting precision of the approximated motion path to the original path.

    A real robot cell setup is modelled in Process Simulate. This lets Process Simulate generate the correct robot code for that specific cell.  Since each robot cell has its own unique setup, a custom script will be developed that changes the universal robot code, that Process Simulate generates, to the custom robot code required in this specific robot cell.

    The software is improved and tested from CAD drawing down to robot code but still needs to be debugged more and needs implementation of some non-existing features.

    Download full text (pdf)
    Circular motion for robotized metal deposition
  • 60.
    Depaquit, Valentin
    University West, Department of Engineering Science.
    Simulation Study of Production Line to Increase its Efficiency through an iterative proces: A Case Study with Sanser2023Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The initial reason for this thesis is the desire of Sansera to reach their target production with this production line. They already invest on conveyors to carry part with more reliability between workstations which has led to an under than expected production increase. To achieve the target production this thesis does a simulation study by developing a virtual model of the production line which is a powerful tool to identify weak point and potential areas for improvement.Through an iterative process of model improvement and analysis, various weaknesses in the production line are identified and addressed, leading to the proposal of different solutions. The study focuses on two key approaches for improving production efficiency, which can be valuable for decision-making purposes. However, the conclusions drawn from these improvements are subject to scrutiny due to the quality and accuracy of the underlying data. The validity of the results depends on the data collected and the assumptions made during the modeling process.In conclusion, this study demonstrates the effectiveness of simulation modeling in optimizing production processes and identifying potential areas for improvement. It highlights the importance of data quality and methodology in drawing reliable conclusions.

  • 61.
    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.

  • 62.
    Erman, Evin
    University West, Department of Engineering Science.
    Robotiserad automation inom Prefabricering2023Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Industrial prefabrication of wooden houses is a technology that is constantly evolving. Sections are built in the factory and then transported to the construction site for assembly. The construction industry at large is dominated by many small and specialized subcontractors who are usually not technically proficient to embrace automation. The sector representing factory-built housing is an exception. Since the products are built in factories, the principles of mass production and mass customization apply as the norm for manufacturing. Mass production in factories is profitable to automate, but automation for mass customization is more difficult and requires new technology. Automation ensures quality in manufacturing. The prefabricated sections can be verified before they leave the factory, together with an optimal construction plan. Newer materials can be applied, tight tolerances achieved, while the built products are not affected by external climatic conditions, which is the case for sitebuilt housing. In order to estimate the needs of automation in the prefab sector, several automation technologies relevant to construction have been reviewed. The purpose of the literature review is to summarize the results of this study and provide an overview of the type of automation that is dominant in the industry. It will help the prefab industry to get a broader picture of building automation, while the research community gets a sense of the industry's "pull" in terms of automation.

  • 63.
    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

  • 64.
    Gay, Clement
    University West, Department of Engineering Science.
    Automatic measurement of surface roughness on a part2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The integration of AM (Additive Manufacturing) process into the industry leads to a new kind of part production. Parts coming from this manufacturing process need to be inspected to have a better understanding of the surface roughness. Thus, the automation of this inspection process must be achieved to perform a total scan of any shape. 

    In this study, the automation process for the scan of an AM part is developed with the ABB robot present in the SMART CELL at the University West SMART cell at Production Technology Centre in Trollhättan, Sweden. The scan is performed by a SJ-210 mechanical stylus sensor from Mitutoyo on a small blade produced by GKN Aerospace. The aim of this work is to adapt the SJ-210 surface roughness sensor to be mounted on the IRB 6700 robot and then automate the scanning process of the surface of a sample. 

    At this stage of the study, the sensor is mounted on the robot and the path of the scanning process is developed. Nevertheless, to trigger and to collect data from the sensor, a physical USB link has been established between the sensor and the computer.

  • 65.
    Glorieux, Emile
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Danielsson, Fredrik
    University West, Department of Engineering Science, Division of Automation Systems.
    Svensson, Bo
    University West, Department of Engineering Science, Division of Automation Systems.
    Lennartson, Bengt
    Chalmers University of Technology, Department of Signals and Systems.
    Optimisation of Interacting Production Stations using a Constructive Cooperative Coevolutionary Approach2014In: Proceedings of 2014 IEEE International Conference on Automation Science and Engineering (CASE), IEEE conference proceedings, 2014, p. 322-327Conference paper (Refereed)
    Abstract [en]

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

  • 66.
    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.

  • 67.
    Glorieux, Emile
    et al.
    WMG, University of Warwick, Coventry, CV4 7AL, United Kingdom (GBR).
    Parthasarathy, Prithwick
    ISolve Technologies, Chennai, 600018, India (IND).
    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.

  • 68.
    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.

  • 69.
    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.

    Download full text (pdf)
    fulltext
  • 70.
    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.

  • 71.
    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.

  • 72.
    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.

  • 73.
    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.

  • 74.
    Gohil, Kuldeepsinh
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Verification and Visualization of Safe Human Robot Collaboration for Robotic Cell2018Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Robotics and Automation field is booming in today´s scenario. Researchers and Technologist comes up with new ideas in the robotics field to achieve a higher productivity, flexibility and efficiency. To achieve the above goals, it shall be required that human and robot share their work space with each other and works in a collaborative nature. Safety is a main concern and in focus. Robot should not injure the operator in any way during working in robotic cell. In this master thesis main focus is to create a various test plans and validate them to ensure the safety level in robotic cell. The test plan should be validated in a real robot environment. The test plans consist of functional and individual verification of safety devices which are being used in a robotic cell at PTC which is known as smart automation lab. Apart from that it includes design simulation of robotic cells with manikins to ensure validation of safety in virtual environment. Design simulation of robotic cell with manikins are created in RobotStudio 6.06. However, smart components, trap routines, SafeMove and offline program in RAPID have been created. Various test results are incorporated in the results section to ensure the verification and validation of safe human robot collaboration of virtual environment in RobotStudio 6.06.

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  • 75.
    Gopinath,, Kiran
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Mimicking of human hand motion on robot arm using point cloud and Machine learning techniques2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Collaborative robots may be required to do complex assembly operations during production and programming the Robot to perform such operations can be a challenging task. If the motions of the human palm could be mimicked on the Robot, it would mitigate the com-plexities involved in teaching such skills to the Robot. This mimicking action could also be used in other applications like robot based painting where it is necessary to capture motion generated by a skilled human hand and reproduce it on a robot.

    To achieve this there may be many methods. A point cloud camera could be used to capture and store point cloud data of an object at different positions and orientations inside the Robot work volume. Corresponding Tool centre point positions and orientations read from the Robot controller serve as labelled data necessary for machine learning.

    The task involves generation of Robot programs to synchronize point cloud capture and robot pose capture resulting in generation of data necessary for machine learning. The point cloud data is generated using Kinect point cloud camera by establishing the communication between the robot and the Kinect V2.

    The objective in this paper is concluded by gathering the point cloud data for limited positions using Kinect V2 which is necessary for machine learning. Since machine learning techniques can be applied for further process huge amount of data is required hence this data is generated.

  • 76.
    Gorla, Mohith Sai
    University West, Department of Engineering Science.
    Explore Correlations between Process and Inspection Data for LDMD-Wire process: Finding Correlations between the in-process monitoring and post process inspection for the LDMD-Wire process2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study seeks to investigate the relationship between in-situ monitoring data and inspection data acquired via Non-Destructive Testing (NDT) techniques in the context of Additive Manufacturing (AM) utilizing the LDMD-Wire process. The purpose of this study is to propose a method to improve the efficacy and accuracy of the validation and certification procedures for additive manufacturing (AM) products. The study describes numerous challenges associated with the administration of high-dimensional data, such as data noise, absence of values, alignment of data, and temporal time synchronization. This study examines the relationship between in-process monitoring and post-process inspection data using various correlation methods. The primary findings indicate that correlation methods can analyze the linear correlation between in-situ monitoring and inspection data in the LDMD-Wire process. The classification model for defining meltpool behavior from the process data has reduced the computational time required to do image processing and image classification. One of the proposed regression models contributes significantly to the detection of anomalies and the prediction of essential aspects, thereby augmenting the validation and certification processes. But the study acknowledges several constraints regarding the material and geometry used in the experimental procedures. Real-world scenarios can be executed effectively using the presented models' methodologies. This study contributes significantly to the advancement of additive manufacturing (AM) technology and has potential applications in various sectors with similar characteristics and data challenges. 

  • 77.
    Gowda Marigowda, Shreyas
    University West, Department of Engineering Science.
    Discrete Event Simulation-based optimization of Sawmill Production: A Study on Advanced Automation and Digitization performed at Stora Enso, Grums.2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to examine the feasibility of automation and digitalization in the Swedish sawmill sector, with a particular emphasis on the Stora Enso Gruvön sawmill. Maintaining a high standard of quality while increasing sawmill productivity is the goal. To examine potential outcomes and pinpoint optimization opportunities, a Discrete Event Simulation (DES) model in Tecnomatix Plant Simulation is built. Historical data supports the conclusion that the simulation model faithfully represents the actual industrial layout and processes. Production flow, throughput, and efficiency are all boosted by the model, as shown experimentally and via simulation. Waste and bottlenecks like long setup periods and insufficient dryer capacity may be found with the model's assistance as well. Three possible scenarios for a sawmill are evaluated, and the third, which incorporates the findings from the other two, has the greatest potential for improving production and efficiency. The research found that DES models accurately portray production systems, which improved decision-making and allowed for more manufacturing process optimization. Though beneficial, DES implementation calls for skilled personnel and ready access to data. Overall, the thesis shows how automation and digitalization may boost sawmill efficiency, and it provides real-world applications for simulation modeling in industrial optimization

  • 78.
    Guldersson, Lukas Auren
    University West, Department of Engineering Science, Division of Production Systems.
    On the development of monitoring system based on laser diode and vision camera: Dimensions and feature extraction of beads and welds2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Laser Directed Energy Deposition with wire (LDEDw) is one of additive manufacturing technologies where a high-density laser beam, is used to melt wire feedstock metal. During processing, free-form 3D shapes are built by depositing material bead-by-bead and layer-by-layer. LDEDw technology gains interest in industry as it gives new opportunities for machining materials that are hard to process by conventional, subtractive technologies, like for example Ni-based superalloys. The possibility to deposit near-net shape components allows costs savings related to material waste, which is a common issue for milling and turning, as well as it introduces new, improved designs, making the parts lighter.

    The laser beam provides a concentrated heat source, allowing for narrow, deep welds and high welding rates. There is a major challenge in this because there is a difficulty for stability and repeatability. So, there should be proper regulation of the deposition and the process parameters by applying a proper monitoring solution that will take measurements for the dimensions of the geometries of weld and beads, thereby finding defects. Only recently, OEMs started providing off-shelf solutions based on the light in the blue range and there is varied limited research preformed within this field.

    In this thesis work, an experimental setup using blue laser light is being put to the test. The setup is proved to be effective in extracting precise dimensional information from scanned images acquired in three different speeds, Low – 10 mm/s, medium –15mm/s and high 20 mm/s, when tested with bead-shape and weld-shape objects of Inconel and stainless-steel. In these three translation speeds, the laser setup can provide a good quality laser line that can be used to define the characteristics of the scanned object: the height, the width and the cut-section area, which provide valuable information for the scanned object. The setup when compared to an off-shelf solution, like the micro-Epsilon scanner, is proved to be at least as effective and in many cases even better in measuring the width. Compared to the results of similar work of researchers, the blue laser experimental setup seems to be on par, producing a min error of 0.0149 mm for height and 0.0023 mm for width.

  • 79.
    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.

  • 80.
    Hagqvist, Petter
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Instrumentation and estimation for high temperature control2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Within a variety of industrially relevant high temperature production processes such as welding, heat treatment and metal deposition, the quality of the manufactured component is largely affected by how well parameters can be controlled during processing. These parameters might be, in the case of metal deposition, power input, material feed, or a parameter which is common for all of the aforementioned processes: material temperature. The ability to correctly measure, or in other ways estimate process parameters is vital in order to successfully control high temperature processes such as above 700 degrees Celsius. In this work, instrumentation and estimation solutions adapted to high temperature control are proposed and implemented with a focus on the laser metal wire deposition process. Special attention is given to temperature measurements on specimens with varying emissivity as commonly found in high temperature processes. A calibration procedure for a single-wavelength pyrometer is also presented together with a general discussion on limitations of such a system for measurands with varying emissivity. A new method for non-contact emissivity compensated temperature estimations using a spectrometer is presented. Simulations and industrially relevant experiments have been carried out validating the method. The theoretical framework for the developed method will be further investigated in the future together with additional experimental validation. In addition to temperature measurements, a method for real-time process control of laser metal wire deposition has been developed and implemented with good results. This control scheme estimates and controls the tool-to-workpiece distance based on resistance measurements. Such measurements allow for placement of instruments outside of the processing chamber and easy integration into existing equipment. Future work will be directed towards incorporation of resistance measurements into an iterative learning control scheme. Also, improvement on the resistance-distance model and further investigation into suitable signal processing methods for the resistance signal will be pursued.

  • 81.
    Hagqvist, Petter
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Automatic detection of material phase transitions from spectroscopic data2013In: Proceedings of the IECON 2013: 39th Annual Conference of the IEEE Industrial Electronics Society, IEEE, 2013, p. 2384-2389Conference paper (Refereed)
    Abstract [en]

    When using a temperaturemeasurementmethod which utilizes spectral information for measuring the temperature of varying emissivity measurands, there is a need for a temperature reference at some point in time. In this work, such a reference is created from the spectral radiance data already used by the temperature measurement method. A method of using knowledge of the measurand material's phase transitions and spectral radiance data as a temperature reference is presented. Through automatical identification of phase transitions from radiance spectra employing signal processing, the temperature is known at a certain instance in time, just like required by the temperature measurement method. Three methods for automatic identification of material phase transitions from spectroscopic data are examined and evaluated. The methods are, based on derivatives, steady-state identification and cross correlation respectively. They are introduced and evaluated using experimental data collected from a solidifying copper sample. All methods proved to identify the phase transitions correctly. The addition of automatic phase transition identification supplements the existing temperature measurement method such that it becomes a stand alone, reference free method for measuring the true absolute temperature of a measurand with varying emissivity.

  • 82.
    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 Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    Chalmers.
    Resistance measurements for control of laser metal wire deposition2014In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 54, no March, p. 62-67Article in journal (Refereed)
    Abstract [en]

    A method for controlling robotized laser metal wire deposition online by electrical resistance metering is proposed. The concept of measuring the combined resistance of the wire and the weld pool is introduced and evaluated for automatic control purposes. Droplet formation, detachment of the wire from the weld pool and stubbing can be hard to avoid during processing due to the sensitive process and short reaction times needed for making on-line adjustments. The implemented system shows a possible route for automatic control of the process wherein such problems can be avoided automatically. The method proves to successfully adjust the distance between the tool and the workpiece through controlling the robot height position, thus increasing stability of the laser metal wire deposition process.

  • 83.
    Hagqvist, Petter
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Sikström, Fredrik
    University West, Department of Engineering Science, Division of Process and Product Development.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    Chalmers.
    Emissivity compensated spectral pyrometry for varying emissivity metallic measurands2014In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 25, no 2, p. 025010-Article in journal (Refereed)
    Abstract [en]

    A novel method for converting electromagnetic spectral radiance information into emperature measurements is presented. It allows for varying spectral emissivity of the metallic measurand during the course of the measurement. Such variations are due to e.g. thermal oxidation or temperature dependent emissivity. Based on the assumption that emissivity changes with time and temperature in a continuous manner, it is further assumed that an emissivity estimate at one sample instance can be derived from the estimated emissivity found at the previous samples together with updated spectral information. This leads to successive recalculations of spectral emissivity together with corresponding temperature values. The proposed algorithm has been proven to give accurate temperature estimates from a measurement based on data captured by a standard UV-Vis spectrophotometer even for an oxidizing Ti-6Al-4V specimen in a temperature range between 900K and 1400K. The method however, is not limited to these wavelength- or temperature-ranges.

  • 84.
    Hagqvist, Petter
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Sikström, Fredrik
    University West, Department of Engineering Science, Division of Process and Product Development.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    Chalmers.
    Emissivity compensated spectral pyrometry-algorithm and sensitivity analysis2014In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 25, no 2, p. 025011-Article in journal (Refereed)
    Abstract [en]

    In order to solve the problem of non-contact temperature measurements on an object with varying emissivity, a new method is herein described and evaluated. The method uses spectral radiance measurements and converts them to temperature readings. It proves to be resilient towards changes in spectral emissivity and tolerates noisy spectral measurements. It is based on an assumption of continuous changes in emissivity and uses historical values of spectral emissivity and temperature for estimating current spectral emissivity.

    The algorithm, its constituent steps and accompanying parameters are described and discussed. A thorough sensitivity analysis of the method is carried out through simulations. No rigorous instrument calibration is needed for the presented method and is therefore industrially tractable.

  • 85.
    Hammar, Samuel
    University West, Department of Engineering Science, Division of Production Systems.
    Automated path planning for supporting autonomous industrial robots in multi-agent systems2021Independent thesis Advanced level (degree of Master (Two Years)), 14 HE creditsStudent thesis
    Abstract [en]

    Due to the paradigm shift from mass production (high volume, low variety) towards mass customization (high volume, high variety) today’s manufacturing systems must adapt to be more flexible. One approach for solving this is with the concept of Plug & Produce, which can be realized using a Multi-Agent System (MAS). In a MAS, the logical control is distributed onto individual, autonomous agents, which are digital representations of physical objects (parts and resources) in the manufacturing system. In these types of solutions agents representing robots can request paths for moving from A to B. These paths need to be generated automatically without human intervention to maximise flexibility. This thesis work aimed at implementing an automatic path planning service in a MAS.The work resulted in a system design for a path planner service that was successfully implemented and evaluated in a simplified multi-agent manufacturing scenario. The evaluation shows that it is possible to implement a path planner as an agent, the results include a comprehensive agent configuration in the system used. The solution is successful in generating a path upon request from an agent within the multi-agent system, without any need for human intervention once the system has been started. Suggestions for future work include improvements to the path planning algorithm used, tests on a real manufacturing cell and the development of a digital twin

  • 86.
    Hampali N, Ajay
    University West, Department of Engineering Science.
    Automatically Updating a Robotics Simulator with Object locations and CAD data2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Individual, autonomous agents, which are digital representations of physical items (parts and resources) in the manufacturing system, receive logical control in a MAS. Agents representing robots can request paths to get from point A to point B in these types of solutions. To maximize flexibility, like to automize the entire process when introducing new products, these pathways must be generated automatically with less human effort such as a few buttons to be pressed to verify or confirm the start procedure. Also, consume less time when deploying and integrating into the existing systems. There could be many scenario’s /complexities in today’s industries regarding customization but solving and applying ideas to reduce these complexities is what all are trying to solve. Traditional mass production manufacturing techniques are difficult to reconfigure for new items because of the various changes which must be made on the production line affecting time, production and costs, and as more customized products become available, new alternatives are required. Manual online programming of robots takes a lot of time and costs lots of money. It is feasible to generate collision-free pathways and entire robot programmes using off-line programming software such as ABB Robot Studio without having to test them on an actual robot. This is advantageous sincenew programmes may be developed without disrupting ongoing work. Off-line programming, on the other hand, is not automatic and takes time for personnel who usethese technologies. Many path planning algorithms are available and finding themost feasible and optimized planning algorithms is also important so that we can deploy that in Multi-Agent System (MAS). Hence this thesis work will help in supporting path planning by providing the flexibility to import the CAD models in their respective locations automatically rather than the manual placements of them in the simulated environment which could provide a collision-free path in the simulation. Utilising ABB’s Robot Studio software for visualising the process with other tools will help to contribute to the development the of Multi-Agent System (MAS) whichin turn contributes to Industry 4.0. 

  • 87.
    Haydar, Abdulmajeed
    University West, Department of Engineering Science, Division of Production Systems.
    Smart Warehouses with Robots and AGVs2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Parker is a global company within motion and control technologies. Parker products that originate from a global leadership position in nine core Motion and Control technologies that include aero-space, climate control, electromechanical, filtration, fluid and gas handling, hydraulics, pneumatics, process control, sealing and shielding [1] [2].

    Parker in Trollhättan produces hydraulics pumps and motors [3]. They produce almost 2730 pumps/motors per week. The factory has worked a lot with automation in the manufacturing sections.

    They are now interested to start with automation in other parts in the factory; especially improve the warehouses by using the robots and AGVs and improve the material handling between different sections by using the AGVs. And of course, they think also about improve the ergonomics and solve the bottleneck. Parker want to analyse the assembly stations and material handling to identify the key areas to start the automation process.

    Parker has a main big warehouse and many buffers around the assembly stations. Material handling now is done manually by using the workers, small trolley or vehicles with a big trolley. The material handling for all assembly stations takes between 512 and 770 minute per shift as manual transfer by workers in addition to several of transfer operations by trolleys and vehicles. And the buffers inside the workplace take about 200 square meters. Wherefore, Parker is very interested to improve the warehouses.

    This work focuses on analysing the current system for material handling in both warehouse and stations. After analysing the current system, the potential for moving from manual material handling to semi- or automated material handling was discussed. Different potentials for improving material handling with the help of robots and AGVs in warehouse and stations has been defined. Testing and validation for all the potentials were the automation can be implemented and started with, the productivity, workspace, safety, in addition to the level of the ergonomics for these working places. The likelihood for solutions success are also presented. And how to optimize the solutions for reaching a high level of automation is discussed.

  • 88.
    Helmersson, Daniel
    University West, Department of Engineering Science.
    Flexible and modular production machines: A guiding framework and the design of a packaging machine2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To increase production and reduce intermediate storage in the factory a new flexible packaging machine is needed. The main purpose of this project is to design a new flexible and modular packaging machine and to create a new framework to use when designing new machines. Current research shows that no framework or practical guide for designing flexible and modular machines exist. A new framework is developed based on a literature study on flexibility in the industry with past, present, and future concepts. The proposed framework is a step-by-step tree/flowchart where each step has a set of rules/guidelines to follow. Along with the flowchart a help section is written to guide the user through the design steps. Existing industry standards are investigated to find a suitable structure for connecting the modules and the machine in the project. Results show that few standards exist in the connectivity structure for the industry.  To lower maintenance costs and increase operational reliability, predictive maintenance using edge computing is investigated. Using edge computing allows the machine to take advantage of predictive maintenance while being offline which makes it suitable for a moveable machine. Evaluation of predictive maintenance show that it still needs more research, and it is complex to implement, which makes it expensive for non-critical machines.The results of this project are a new proposed framework that was used in the project to design a new packaging machine and a flexible PLC program that is easily adaptable for changing modules. The proposed framework fills a gap in the practical usage of known concepts and was used while designing the new machine to evaluate its usability.

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  • 89.
    Heralic, Almir
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Monitoring and Control of Robotized Laser Metal-Wire Deposition2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis gives a number of solutions towards full automation of the promising manufacturing technology Robotized Laser Metal-wire Deposition (RLMwD). RLMwD offers great cost and weight saving potentials in the manufacturing industry. By metal deposition is here meant a layered manufacturing technique that builds fully-dense structures by melting metal wire into solidifying beads, which are deposited side by side and layer upon layer. A major challenge for this technique to be industrially implemented is to ensure process stability and repeatability. The deposition process has shown to be extremely sensitive to the wire position and orientation relative to the melt pool and the deposition direction. Careful tuning of the deposition tool and process parameters are therefore important in order to obtain a stable process and defect-free deposits. Due to its recent development, the technique is still manually controlled in industry, and hence the quality of the produced parts relies mainly on the skills of the operator. The scientific challenge is therefore to develop the wire based deposition process to a level where material integrity and good geometrical fit can be guaranteed in an automated and repeatable fashion. This thesis presents the development of a system for on-line monitoring and control of the deposition process. A complete deposition cell consisting of an industrial robot arm, a novel deposition tool, a data acquisition system, and an operator interface has been developed within the scope of this work. A system for visual feedback from the melt pool allows an operator to control the process from outside the welding room. A novel approach for automatic deposition of the process based on Iterative Learning Control is implemented. The controller has been evaluated through deposition experiments, resembling real industrial applications. The results show that the automatic controller increases the stability of the deposition process and also outperforms a manual operator. The results obtained in this work give novel solutions to the important puzzle towards full automation of the RLMwD process, and full exploitation of its potentials.

  • 90.
    Heralic, Almir
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Charles, Corinne
    University West, Department of Engineering Science, Division of Production Engineering. University West, Department of Engineering Science, Division of Welding Technology.
    Dzevad, Imamovic
    Volvo Aero Coorporation.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Lennartson, Bengt
    Dep of signal and systems, Chalmers.
    Towards stable high-speed metal-wire deposition, Part I: Parameter studyIn: Journal of laser applications, ISSN 1042-346X, E-ISSN 1938-1387Article in journal (Refereed)
  • 91.
    Heralic, Almir
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Automatic in-process control of laser metal-wire deposition based on sensor feedback2011In: 30th Interantional Congress on Applications of Lasers & Electro-Optics, ICALEO 2011: Orlando October 23-27, 2011. Code 87581|, 2011, p. 211-220Conference paper (Refereed)
    Abstract [en]

    This paper describes alasermetaldepositionsystem that isbasedon robotizedlaserwelding andwirefiller material. The system has been found suitable for the manufacture of simple but large shapes with high metallurgical requirements such as bosses or flanges found on aero engine components. Several benefits have been identified with the usage ofwirefiller compared to powderized feedstock, such as betterprocessefficiency, higherdepositionrates, and cleaner working environment. Thewirebaseddepositionprocessis however sensitive to disturbances and thus requires continuous monitoring and adjustments.Inthis work a 3D scanning system is described forautomaticin-processcontrolof thedeposition. The goal is to obtain a flat surface for each deposited layerinorder to ensure stabledeposition. The deviationsinthe layer height are compensated by controlling thewirefeed rate. The system is tested throughdepositionof small cylindrical bosses and the results show that the proposedcontrolapproach is suitable forautomaticdepositionof such structures. The material consideredinthis paper is Ti-6Al-4V deposited on plates of same material. The paper presents the equipment and thecontrolstrategy and discusses practical issues regarding thesensorused.

  • 92.
    Heralic, Almir
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Lennartson, Bengt
    Dep of signal and systems, Chalmers.
    Height control of laser metal-wire deposition based on iterative learning control and 3D scanning2012In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 50, no 9, p. 1230-1241Article in journal (Refereed)
    Abstract [en]

    Laser Metal-wire Deposition is an additive manufacturing technique for solid freeform fabrication of fully dense metal structures. The technique is based on robotized laser welding and wire filler material, and the structures are built up layer by layer. The deposition process is, however, sensitive to disturbances and thus requires continuous monitoring and adjustments. In this work a 3D scanning system is developed and integrated with the robot control system for automatic in-process control of the deposition. The goal is to ensure stable deposition, by means of choosing a correct offset of the robot in the vertical direction, and obtaining a flat surface, for each deposited layer. The deviations in the layer height are compensated by controlling the wire feed rate on next deposition layer, based on the 3D scanned data, by means of iterative learning control. The system is tested through deposition of bosses, which is expected to be a typical application for this technique in the manufacture of jet engine components. The results show that iterative learning control including 3D scanning is a suitable method for automatic deposition of such structures. This paper presents the equipment, the control strategy and demonstrates the proposed approach with practical experiments.

  • 93.
    Heralic, Almir
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Lennartson, Bengt
    Dep of signal and systems, Chalmers.
    Towards stable high-speed metal-wire deposition, Part II: Automatic deposition using feedback controlIn: Article in journal (Refereed)
  • 94.
    Heralic, Almir
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Ottosson, Mattias
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering. University West, Department of Engineering Science, Division of Production Systems.
    Lennartson, Bengt
    University West, Department of Engineering Science, Division of Production Systems. Dep of signal and systems, Chalmers.
    Automation of laser metal deposition for the manufacture of fully dense structures2011In: 4th International Swedish Production Symposium, SPS11: 3-4 May, Lund, Sverige / [ed] Jan-Eric Ståhl, Swedish Productio Academy , 2011, p. 219-227Conference paper (Refereed)
  • 95.
    Heralic, Almir
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Ottosson, Mattias
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Kristiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering. University West, Department of Engineering Science, Division of Production Systems.
    Norlander, Torbjörn
    Volvo Aero Coorporation.
    Geometry control of laser metal deposition for the manufacture of complex structures in the aero industry2011In: 20th International Society for Airbreathing Engines Conference, ISABE 2011: September 12-16, 2011 Gothenburg, 2011, p. 1666-1674Conference paper (Refereed)
  • 96.
    Heras Aguilar, Sergio
    University West, Department of Engineering Science, Division of Production System.
    Comparison and visualization of robot program modifications: Applied on ABB industrial robots at Volvo Cars Corporation2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Volvo Cars Corporation creates robot programs off-line for all new robot implementations for virtual commissioning. These virtually created robot programs are then downloaded to the real robot, after the installation has been carried out, to be tested before they are fully operational. These tests are spanned from robot installation until full production, adjusting the robot programme according to Volvo Cars specification and correcting errors that the robot program may have. Changes of the robot programs will be saved each time it is modified, generating a series of backups for each robot until the robot is correctly adjusted along all the steps of the process. To improve the offline programming there is a necessity for visualize the modifications made during the physical robot commissioning. The objective of this thesis is to identify, categorise, quantify and visualize modifications between each different backup of a robot. A software application has been developed using Microsoft Visual Studio using C#. The application is designed in windows for different types of data. It enables the user to compare two robot programs (two different backup programs from the tests) from one robot and see the result between them graphically. The graphs are designed interactively so that the user can filter the information to see the desired data from the robot programs comparison. Key performance indicators (KPIs) has been specified for RobTargets and Procedures according to Volvo Cars Corporation requests. These KPIs are implemented and visualised in a graphical representation.

    Download full text (pdf)
    fulltext
  • 97.
    Johansson, Dahniel
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Automated inspection of defects onmetal surfaces2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aerospace industry is today manufacturing a large variety of parts. Some which are classifiedas critical, these parts are today manually inspected and validated according to proceduresand standards. The Aero space industry is interested in a product that can aid in the process of inspection and validation to reduce the manual work.

    The identification of the needs is done by a study visit at GKN Aerospace Sweden, in Trollhättan, and through questions and discussions with the staff from GKN. The main need is identified as an automated visual inspection of defects on metal surfaces. The automated inspection is divided into sub-functions, which in turn allows identification of potential robot tool modules.

    Modular design is a method which enables variations and updates of a product's features without being locked into a singular solution. Modular design also allows sustainability due to the ease of upgrading and recycling a product.

    The robot tool modules are developed into several concepts. The concepts are 3D modelled in CAD software and in parallel with the concept development, a simulation of an inspection procedure, including the 3D models, is developed in ABBs simulation environment RobotStudio. The development of the solution for the automated inspection is an iterative process. When the simulated solution is satisfying functionality and customer needs, construction drawings are created for the modules of the robot tool.

    The simulation and the manufactured tools are implemented in a real robot cell and as a result, the objective the project is met, an automated inspection of defects on metal surfaces.

  • 98.
    Joseph Peter, Samuel Abishek
    University West, Department of Engineering Science.
    Material Handling by Automated Guided Vehicle System Using Discrete-Event Simulation: A case study at Autoliv, Thailand2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A case study for this project is performed at Autoliv in Thailand the company uses a lean production flow approach. This manufacturing plant operates on the level of Industry 3.0, which automates processes using information technology. The case study scenario in manufacturing plants that runs in industrial automation 3.0 has some problems in material handling under the logistics division. By implementing AGV (Automated Guided Vehicle) with help of simulation, the time reduction factor through route and time optimization can be processed and displayed. This will have a direct impact on increasing the material handling efficiency in the production plant. The simulation used for AGV in plant layout is Discrete Event Simulation (DES), which divides each event according to its time. Siemens’s Tecnomatix Plant Simulation software is used as a software. This software handles complex production systems and provides control methods.

    In this thesis work, the entire plant is implemented in the simulated environment based on the plant layout as per dimensions. Then the AGV routing is done from source to destination. The stations are made as per the requirements between the source and the destination for loading from/ unloading to AGV. The processing time of these stations is given as inputs and the simulation is run for a shift to get the throughput. The specification of the AGV such as speed and dimensions given in the simulated environment is taken from the case study of AGV. A total of 55 AGV models’ are studied and 40 of them are selected for this particular plant layout, they are selected based on their features along with the throughput of units transferred from source to destination. The parameters of the AGV are based on the case study of AGV models. The unit throughput acquired in the simulated environment by the AGV is 20% to 22.5% more efficient than manual material handling.

    Download full text (pdf)
    fulltext
  • 99.
    Jovignot, Lucie
    University West, Department of Engineering Science.
    Towards Automated Reversal of Manufacturing Processes: Guideline Development for Operator Assistance and Process Restoration2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the era of Industry 4.0, the complexity of manufacturing systems has increased significantly, making the task of restarting a process after a failure more challenging. Instead of restarting the entire process, there is a growing need to restore the process to its previous state, which can be a quicker and more efficient approach. However, performing maintenance tasks accurately and efficiently is not easy, as they often involve numerous intricate steps. 

    To address these challenges, this thesis focuses on the development of a guideline to support operators in performing corrective maintenance tasks. The primary goal is to provide operators with guidance and assistance throughout the process of restoration, minimizing human error and improving overall efficiency.

    The thesis initially explores research on generating automated steps for reversing manufacturing processes. While the research phase did not yield a definitive solution, valuable insights were gained. The thesis then shifts its focus to the practical implementation of a guideline that can be displayed on the Human-Machine Interface (HMI) of a Plug & Produce robot cell. The guideline is designed to provide step-by-step instructions to operators, ensuring they follow the correct sequence of actions to restore the process.

  • 100.
    Juste, Alexandre
    University West, Department of Engineering Science, Division of Production Systems.
    Energy consumption reduction for gantry crane through simulation: A case study at a car engine manufacturing plant2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Reducing energy consumption is at the core of many researches over the last decades. These researches are motivated by an increasing awareness of the environmental situation and by the economical aspect of energy savings. Companies in possession of large production site like Volvo increase their productivity through the usage of automated lines of production.

    This thesis outline how energy savings can be achieved for mobile devices like a gantry crane. A workflow analysis of a production line has been achieved, this analysis resulted in a route modification for the gantry crane without altering the production rate of the line and saving energy at the same time. After adapting the route of the gantry crane, a mapping of the production in function of the velocity and acceleration of the gantry was conducted.

    By studying the impact of the gantry crane velocity on the energy consumption, the previous mapping lead to adjusted values of speed and acceleration for the gantry crane carriage. A new route and velocity values for the gantry crane were found and at the same time keeping the production rate unchanged and therefore ensuring a profitable scenario for the company and the environment.

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