| 1. |
- Dahl, Martin, 1984, et al.
(författare)
-
Integrated Virtual Preparation and Commissioning: supporting formal methods during automation systems development
- 2016
-
Ingår i: IFAC-PapersOnLine. - : Elsevier BV. - 2405-8963. ; 49:12, s. 1939-1944
-
Konferensbidrag (refereegranskat)abstract
- Virtual commissioning – the development and validation of industrial control systems against a simulation model – is attracting interest in the automotive industry. The main motivation for its use is that control systems can start to be integrated and tested before the construction of the physical system. In addition to this, the ability to continuously test can lead to increased reliability and enables better coping with late changes. At the same time, using formal methods during production preparation and control system design promise similar benefits. Formal methods however, are not seeing the same surge in interest – they are rarely used in the automotive industry. In this paper a framework is proposed, Integrated Virtual Preparation and Commissioning, where virtual commissioning models are used as a base for preparation and control system implementation assisted by formal methods. The extensive use of simulation in virtual commissioning allows computation results from formal methods to be continuously validated by visual inspection and using existing analysis tools (e.g. collision detection methods). The framework is applied in a case study, where the combination of a simulation model and a formal model is used as an aid in generating operation sequences for validation during production preparation. The resulting formal model can be used to study the behavior of the production system before a control system has been implemented.
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| 2. |
- Dahl, Martin, 1984, et al.
(författare)
-
Sequence Planner: Supporting Integrated Virtual Preparation and Commissioning
- 2017
-
Ingår i: IFAC-PapersOnLine. - : Elsevier BV. - 2405-8963. ; 50:1, s. 5818-5823
-
Konferensbidrag (refereegranskat)abstract
- It is essential to understand the operation sequences of a production system when designing or changing it. This paper will demonstrate how the software tool Sequence Planner (SP) not only supports this understanding by sequence visualization, but also improves the solution using optimization and verification. SP is a tool for modeling and analyzing automation systems. The tool has been developed since 2007 with an initial focus on supporting engineers when developing control code for programmable logical controllers. Today, SP is a micro-service architecture, usable in various areas like runtime control, online monitoring, energy optimization, and even emergency department patient planning. This paper presents a use case at an automotive company, where the operation sequences in a large number of automated robot stations, need to be modified. SP, together with virtual commissioning tools, automates this modification by identifying, optimizing, verifying and simulating operation sequences, and then updates the robot and control programs. This use case demonstrates the strength of SP and its architecture and how it is used for integrated virtual preparation and commissioning.
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| 3. |
- Khan, Adnan, 1984, et al.
(författare)
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Digital Twin for Legacy Systems: Simulation Model Testing and Validation
- 2018
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Ingår i: IEEE International Conference on Automation Science and Engineering. - 2161-8070 .- 2161-8089. ; 2018-August, s. 421-426
-
Konferensbidrag (refereegranskat)abstract
- In this paper, an approach to incorporate a digitaltwin for legacy production systems is presented. Hardware-in-the-loop setups are routinely used by manufacturing companiesto carry out virtual commissioning. However, manufacturingcompanies having online legacy production systems are stillstruggling to incorporate a digital twin due to the absence ofverified and validated simulation models. Companies that usevirtual commissioning as a part of their engineering tool chain,usually perform offline verification of the simulation model.This approach is typically based on visual inspection and is atedious task as each aspect of the model has to be visuallyvalidated. For legacy systems, only assessing the behaviorvisually in the absence of updated documents can result in anincorrect simulation model, i.e. simulating incorrect behaviorwith respect to the specification. Due to this, such simulationmodels cannot be incorporated in the engineering tool chain,as the simulated results can lead to improper decisions and caneven cause equipment damage. This paper presents a platformand an approach, based on model-based testing, that is a firststep for manufacturing companies to incorporate a validatedsimulation model for existing online production systems thatwill serve as a digital twin.
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| 4. |
- Dahl, Martin, 1984-, et al.
(författare)
-
A 2,000-Year Record of Eelgrass (Zostera marina L.) : Colonization Shows Substantial Gains in Blue Carbon Storage and Nutrient Retention
- 2024
-
Ingår i: Global Biogeochemical Cycles. - : John Wiley & Sons. - 0886-6236 .- 1944-9224. ; 38:3
-
Tidskriftsartikel (refereegranskat)abstract
- Assessing historical environmental conditions linked to habitat colonization is important for understanding long-term resilience and improving conservation and restoration efforts. Such information is lacking for the seagrass Zostera marina, an important foundation species across cold-temperate coastal areas of the Northern Hemisphere. Here, we reconstructed environmental conditions during the last 14,000 years from sediment cores in two eelgrass (Z. marina) meadows along the Swedish west coast, with the main aims to identify the time frame of seagrass colonization and describe subsequent biogeochemical changes following establishment. Based on vegetation proxies (lipid biomarkers), eelgrass colonization occurred about 2,000 years ago after geomorphological changes that resulted in a shallow, sheltered environment favoring seagrass growth. Seagrass establishment led to up to 20- and 24-fold increases in sedimentary carbon and nitrogen accumulation rates, respectively. This demonstrates the capacity of seagrasses as efficient ecosystem engineers and their role in global change mitigation and adaptation through CO2 removal, and nutrient and sediment retention. By combining regional climate projections and landscape models, we assessed potential climate change effects on seagrass growth, productivity and distribution until 2100. These predictions showed that seagrass meadows are mostly at risk from increased sedimentation and hydrodynamic changes, while the impact from sea level rise alone might be of less importance in the studied area. This study showcases the positive feedback between seagrass colonization and environmental conditions, which holds promise for successful conservation and restoration efforts aimed at supporting climate change mitigation and adaptation, and the provision of several other crucial ecosystem services. © 2024. The Authors.
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| 5. |
- Dahl, Martin, 1984, et al.
(författare)
-
Automatic modeling and simulation of robot program behavior in integrated virtual preparation and commissioning
- 2017
-
Ingår i: Procedia Manufacturing. - : Elsevier BV. - 2351-9789. ; 11, s. 284-291
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a method where the behavior of a robot cell is automatically modeled based on existing robot programs and a simulation model of the cell. Robot programs from the shop floor are uploaded into a virtual manufacturing tool, and a formal model is then generated from the robot programs. Then, control logic is automatically calculated, and the fastest possible execution order is found by using the generated model to formulate an optimization problem. The result is continuously analyzed and validated by simulation in the virtual manufacturing tool.
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| 6. |
- Dahl, Martin, 1984, et al.
(författare)
-
Control components for Collaborative and Intelligent Automation Systems
- 2019
-
Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - 1946-0759 .- 1946-0740. ; 2019-September, s. 378-384
-
Konferensbidrag (refereegranskat)abstract
- Collaborative and intelligent automation systems need intelligent control systems. Some of this intelligence exist on a per-component basis in the form of vision, sensing, motion, and path planning algorithms. To fully take advantage of this intelligence, also the coordination of subsystems need to exhibit intelligence. While there exist middleware solutions that eases communication, development, and reuse of such subsystems, for example the Robot Operating System (ROS), good coordination also requires knowledge about how control is supposed to be performed, as well as expected behavior of the subsystems. This paper introduces lightweight components that wraps ROS2 nodes into composable control components from which an intelligent control system can be built. The ideas are implemented on a use case involving collaborative robots with on-line path planning, intelligent tools, and human operators.
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| 7. |
- Dahl, Martin, 1984-, et al.
(författare)
-
First assessment of seagrass carbon accumulation rates in Sweden: A field study from a fjord system at the Skagerrak coast
- 2023
-
Ingår i: PLoS Climate. - : Public Library of Science (PLoS). - 2767-3200. ; 2:1
-
Tidskriftsartikel (refereegranskat)abstract
- Seagrass meadows are globally important blue carbon sinks. In northern cold-temperate regions, eelgrass (Zostera marina) is the dominant seagrass species, and although their sedimentary carbon stocks have been quantified across regions, information regarding the CO2 withdrawal capacity as carbon sinks remains scarce. Here we assessed the carbon (Corg) accumulation rates (CARs) and stocks as well as the organic matter sources in five seagrass meadows in the Gullmar Fjord area on the Swedish Skagerrak coast. We found that the mean (±SD) CAR was 14 ± 3 g Corg m-2 yr-1 over the last ~120–140 years (corresponding to a yearly uptake of 52.4 ± 12.6 g CO2 m-2). The carbon sink capacity is in line with other Z. marina areas but relatively low compared to other seagrass species and regions globally. About half of the sedimentary carbon accumulation (7.1 ± 3.3 g Corg m-2 yr-1) originated from macroalgae biomass, which highlights the importance of non-seagrass derived material for the carbon sink function of seagrass meadows in the area. The Corg stocks were similar among sites when comparing at a standardized depth of 50 cm (4.6–5.9 kg Corg m-2), but showed large variation when assessed for the total extent of the cores (ranging from 0.7 to 20.6 kg Corg m-2 for sediment depths of 11 to at least 149 cm). The low sediment accretion rates (1.18–1.86 mm yr-1) and the relatively thick sediment deposits (with a maximum of >150 cm of sediment depth) suggests that the carbon stocks have likely been accumulated for an extended period of time, and that the documented loss of seagrass meadows in the Swedish Skagerrak region and associated erosion of the sediment could potentially have offset centuries of carbon sequestration.
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| 8. |
- Dahl, Martin, 1984, et al.
(författare)
-
Guard extraction for modeling and control of a collaborative assembly station
- 2020
-
Ingår i: IFAC-PapersOnLine. - : Elsevier BV. - 2405-8963. ; 53:4, s. 223-228
-
Konferensbidrag (refereegranskat)abstract
- A transition system represented by guards and actions can be amended by new guards computed in order to satisfy some specification. If the transition system is the result of composing smaller state machines, guard extraction can be used to put the new guards onto the guards the original state machines. Planning and verification can then be performed directly on the system with additional guards. In this paper we discuss the benefits of applying guard extraction as part of the modeling work in a modular control architecture, where reusable resources are composed using specifications. We show with an example from the development of an industrial demonstrator that even if the specification language is limited to invariant propositions, in practice many common safety specifications can be expressed when combined with a notion of which transitions are allowed to be restricted.
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| 9. |
- Dahl, Martin, 1984-, et al.
(författare)
-
Impacts of land-use change and urban development on carbon sequestration in tropical seagrass meadow sediments
- 2022
-
Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136 .- 1879-0291. ; 176
-
Tidskriftsartikel (refereegranskat)abstract
- Seagrass meadows store significant carbon stocks at a global scale, but land-use change and other anthropogenic activities can alter the natural process of organic carbon (Corg) accumulation. Here, we assessed the carbon accumulation history of two seagrass meadows in Zanzibar (Tanzania) that have experienced different degrees of disturbance. The meadow at Stone Town has been highly exposed to urban development during the 20th century, while the Mbweni meadow is located in an area with relatively low impacts but historical clearing of adjacent mangroves. The results showed that the two sites had similar sedimentary Corg accumulation rates (22–25 g m−2 yr−1) since the 1940s, while during the last two decades (∼1998 until 2018) they exhibited 24–30% higher accumulation of Corg, which was linked to shifts in Corg sources. The increase in the δ13C isotopic signature of sedimentary Corg (towards a higher seagrass contribution) at the Stone Town site since 1998 points to improved seagrass meadow conditions and Corg accumulation capacity of the meadow after the relocation of a major sewage outlet in the mid–1990s. In contrast, the decrease in the δ13C signatures of sedimentary Corg in the Mbweni meadow since the early 2010s was likely linked to increased Corg run-off of mangrove/terrestrial material following mangrove deforestation. This study exemplifies two different pathways by which land-based human activities can alter the carbon storage capacity of seagrass meadows (i.e. sewage waste management and mangrove deforestation) and showcases opportunities for management of vegetated coastal Corg sinks.
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| 10. |
- Dahl, Martin, 1984, et al.
(författare)
-
Interactive formal specification for efficient preparation of intelligent automation systems
- 2022
-
Ingår i: CIRP Journal of Manufacturing Science and Technology. - : Elsevier BV. - 1755-5817 .- 1878-0016. ; 38, s. 129-138
-
Tidskriftsartikel (refereegranskat)abstract
- The automation system of the future will consist of an increasing amount of complex resources, such as collaborative robots and/or autonomously roaming robots for material handling. To control these devices in an environment shared with human operators require state of the art computer perception and motion planning algorithms to be used as part of the automation system. This new type of intelligent automation system, where intelligent machines and learning algorithms are replacing more traditional automation solutions, requires new methods and workflows to keep up with the increase in complexity. This paper presents an interactive and iterative framework for solving some of these new challenges. The framework supports model-based control system preparation performed simultaneously to preparation of 3D geometries, positioning of robots, and tool design. The workflow enables an interactive preparation process, where new resources and constraints can be added to a live (real or simulated) automation system and control system failures can be analyzed in familiar tools for virtual preparation. Additionally, the paper describes how the integrated preparation process was applied to reconfiguring an industrial use case that includes a collaborative robot working side by side with a human operator, smart tools, and a vision system for localizing both work objects and tools.
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| 11. |
- Dahl, Martin, 1984-
(författare)
-
Natural and human-induced carbon storage variability in seagrass meadows
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Seagrasses are considered highly important CO2 sinks, with the capacity to store substantial quantities of organic carbon in the living biomass and sediments, and thereby acting as a buffer against climate change. In this thesis, I have studied carbon storage variability in temperate and tropical seagrass habitats and identified factors influencing this variation. In addition, as seagrass areas are decreasing worldwide, I have assessed effects of different anthropogenic disturbances on carbon sequestration processes. The result from this thesis showed that there was a large variation in carbon storage within and among temperate, tropical and subtropical regions. The highest organic carbon stocks were found in temperate Zostera marina meadows, which also showed a larger carbon storage variability than the subtropical and tropical seagrass habitats. The tropical and subtropical seagrass meadows had inorganic carbon pools exceeding the organic carbon accumulation, which could potentially weakens the carbon sink function. The variability in organic carbon stocks was generally strongly related to the sediment characteristics of the seagrass habitats. In Z. marina meadows, the strength of the carbon sink function was mainly driven by the settings of the local environment, which in turn indicates that depositional areas will likely have higher organic carbon stocks than more exposed meadows, while in the tropics seagrass biomass was also influencing sedimentary carbon levels. Furthermore, locations with large areas of seagrass were associated with higher carbon storage in tropical and subtropical regions, which could be related to increased accumulation of both autochthonous and allochthonous carbon. In an in situ experiment, impacts on carbon sequestration processes from two types of disturbances (with two levels of intensity) were tested by simulating reduced water quality (by shading) and high grazing pressure (through removal of shoot biomass). At high disturbance intensity, reductions in the net community production and seagrass biomass carbon were observed, which negatively affected carbon sequestration and could impact the sedimentary organic carbon stocks over time. In the treatments with simulated grazing, erosion was also seen, likely due to an increase in near-bed hydrodynamics. When experimentally testing effects of increased current flow on organic carbon suspension in Z. marina sediment, a ten-fold release of organic carbon with higher current flow velocities was measured, which resulted in an increase in the proportion of suspended organic carbon by three times in relation to other sediment particles. Therefore, periods with enhanced hydrodynamic activity could result in a removal of organic carbon and thereby likely reduce the seagrass meadows’ capacity to store carbon. The findings of this thesis add to the emerging picture that there is a large natural variability in seagrasses’ capacity to store carbon, and highlight how human-induced disturbances could negatively affect the carbon sink function in seagrass meadows.
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| 12. |
- Dahl, Martin, 1984, et al.
(författare)
-
Sequence Planner: A Framework for Control of Intelligent Automation Systems
- 2022
-
Ingår i: Applied Sciences (Switzerland). - : MDPI AG. - 2076-3417. ; 12:11
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a framework that tackles the challenges met in the development of automation systems featuring collaborative robotics and other machines that have some degree of autonomy. These machines rely on online algorithms for both sensing and acting in order to achieve a very high level of flexibility. To take advantage of these new machines and algorithms, control systems must also be increasingly flexible. In this paper, we present a framework for control of this new class of intelligent automation systems called Sequence Planner (SP), which helps with control of both traditional automation equipment and machines with autonomy. To aid the complex task of developing automation control solutions, SP relies on supporting algorithms for control logic synthesis and online planning. SP has been implemented with plug-in support for the Robot Operating System (ROS) and applied to an industrial demonstrator. We present our findings on how SP performed as a control system for this demonstrator, where we show that it is an adequate approach to implement automation for a highly flexible single station system. As a standardized way of automating such systems is missing, we hope that our contribution will provide a foundation for how to develop intelligent automation systems.
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| 13. |
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| 14. |
- Silas, Mathew O., et al.
(författare)
-
Seascape configuration influences big blue octopus (Octopus cyanea) catches: Implications for a sustainable fishery
- 2023
-
Ingår i: FISHERIES RESEARCH. - : Elsevier. - 0165-7836 .- 1872-6763. ; 264
-
Tidskriftsartikel (refereegranskat)abstract
- Seascape configuration is known to influence fish distribution and abundance in coastal waters. However, there is little information regarding how the shape of the coastal seascape influences catches of landed fisheries species, particularly so in the understudied western Indian Ocean (WIO). With focus on big blue octopus (Octopus cyanea), which is a widely found cephalopod species in the WIO, we compared landed catches (biomass, catch rate, and density) in submerged and exposed reefs, and explored the influence of proximity to fishing villages and reef habitat size on octopus landings. We used fishery-dependent data collected between 2018 and 2020 from eight landing sites spread across the Tanzanian coast. We found a strong relationship between biomass of octopus catch and distance from fished reefs to fishing villages, with higher fished biomass on reefs farther away. Octopus densities were higher, while catch rates were lower, on reefs very close to (within one km distance from) fishing villages compared to more distant reefs. In general, submerged reefs provided higher catches than exposed reefs. The low octopus catches on the exposed reefs were attributed to high fishing pressure, while submerged reefs that are only accessible through diving provide optimal areas for octopuses to grow. Octopus catches were, however, not significantly affected by reef size. The findings suggest that management policies should propor-tionate fishing efforts to ensure sustainable exploitation of reefs and associated fishery resources.
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| 15. |
- Vinogradova, Olena, et al.
(författare)
-
3000 Years of past regional and local land-use and land-cover change in the southeastern Swedish coastal area : Early human-induced increases in landscape openness as a potential nutrient source to the Baltic Sea coastal waters
- 2024
-
Ingår i: The Holocene. - : Sage Publications. - 0959-6836 .- 1477-0911. ; 34:1, s. 56-73
-
Tidskriftsartikel (refereegranskat)abstract
- Reconstructions of past land use and related land-cover changes at local and regional scales are needed to evaluate the potential long-term impacts of land use on the coastal waters of the Baltic Sea. In this purpose, we selected the Gamleby area at the Swedish Baltic Sea coast for a case study. We use a new, high resolution pollen record from a small lake (Lillsjön) located 3.6 km NNW of the bay Gamlebyviken and detailed analysis of the available archeological data to reconstruct local land-use changes over the last 3000 years. To estimate land-cover change at local (2–3 km radius area) and regional (50 km radius area) scales we use four additional, published pollen records from two small and two large lakes (25–70 km S of Lillsjön) and the Landscape Reconstruction Algorithm, a pollen-vegetation modeling scheme. Results show that regional and local (small lakes Lillsjön and Hyttegöl) land-cover changes are comparable over the last 1500 years (Late Iron Age to present), and that landscape openness was much larger locally than regionally (difference of 20–40% cover over the last 500 years). The periods of largest potential impacts on the Gamlebyviken Bay from regional and local land use are 200–950 CE (Late Iron Age) and 1450 CE to present, and of lowest potential impacts 950–1450 CE. The question on whether the large landscape openness 1150–50 BCE and significant afforestation 50 BCE–200 CE reconstructed for Lillsjön’s area are characteristic of the Gamlebyviken region will require additional pollen records in the catchment area.
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| 16. |
- Albo, Anton, 1991, et al.
(författare)
-
A framework concept for data visualization and structuring in a complex production process
- 2019
-
Ingår i: Procedia Manufacturing. - : Elsevier BV. - 2351-9789. ; 38, s. 1642-1651
-
Konferensbidrag (refereegranskat)abstract
- This paper provides a concept study for a visual interface framework together with the software Sequence Planner for implementation on a complex industrial process for extracting process information in an efficient way and how to make use of a lot of data to visualize it in a standardized human machine interface for different user perspectives. The concept is tested and validated on a smaller simulation of a paint booth with several interconnected and supporting control systems to prove the functionality and usefulness in this kind of production system. The paper presents the resulting five abstraction levels in the framework concept, from a production top view down to the signal exchange between the different resources in one production cell, together with additional features. The simulation proves the setup with Sequence Planner and the visual interface to work by extract and present process data from a running sequence.
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| 17. |
- Dahl, Martin, 1984, et al.
(författare)
-
Application of the sequence planner control framework to an intelligent automation system with a focus on error handling
- 2021
-
Ingår i: Machines. - : MDPI AG. - 2075-1702. ; 9:3
-
Tidskriftsartikel (refereegranskat)abstract
- Future automation systems are likely to include devices with a varying degree of autonomy, as well as advanced algorithms for perception and control. Human operators will be expected to work side by side with both collaborative robots performing assembly tasks and roaming robots that handle material transport. To maintain the flexibility provided by human operators when introducing such robots, these autonomous robots need to be intelligently coordinated, i.e., they need to be supported by an intelligent automation system. One challenge in developing intelligent automation systems is handling the large amount of possible error situations that can arise due to the volatile and sometimes unpredictable nature of the environment. Sequence Planner is a control framework that supports the development of intelligent automation systems. This paper describes Sequence Planner and tests its ability to handle errors that arise during execution of an intelligent automation system. An automation system, developed using Sequence Planner, is subjected to a number of scenarios where errors occur. The error scenarios and experimental results are presented along with a discussion of the experience gained in trying to achieve robust intelligent automation.
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| 18. |
- Dahl, Martin, 1984
(författare)
-
Preparation and control of intelligent automation systems
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the automation systems of tomorrow, it is likely that the devices included have various degrees of autonomy, and include advanced algorithms for perception and control. Human operators will be expected to work together with collaborative robots as well as with roaming robots for material handling. The volatile nature of the environment of such intelligent automation systems lead to an enormous amount of possible situations that can arise and which need to be suitably handled. This complexity makes development of control systems for intelligent automation systems difficult using traditional methods. As an alternative, this thesis presents a model-based control framework, which uses a combination of formal specification and automated planning. The proposed framework allows for defining the intentions of the automation system on a high level, which enables decisions that influence when things should occur to be modeled using logical constraints, rather than programming. To achieve a modular framework, low level, reusable, resource models are composed by 1) formal specification to ensure safety and 2) applying an abstraction called an operation, which couples the reusable resources to the intentions of the system. By planning also the resources' detailed actions, the operations can, when possible, be completed regardless of the resources' current state. This eases error-recovery, as resources do not have to be reset when an error occurs. Additionally, the thesis proposes an iterative and interactive workflow for integrating the proposed model-based control framework into a virtual preparation process, using computer-based simulation as a tool for validating formal specifications. The control framework allows for adding new constraints to a running system, enabling an efficient and interactive preparation process. The framework has been applied to a use case from final assembly, which features human-robot collaboration. Experimental results on the ability to handle unforeseen errors and planning performance are presented.
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| 19. |
- Dahl, Martin, 1984
(författare)
-
Towards an integrated framework for modeling, control, and validation of production systems
- 2018
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To prepare a production system before installation includes a multitude of computer assisted tasks. Virtual preparation, including many simulation supported activities, has made great strides during the last decade. Industrial robots are routinely programmed offline in simulation environments. Assembly sequences and material transportation are validated using simulation, as well as the ergonomics of human workers. In recent years, virtual commissioning has been added as another possible activity that can be performed using a simulated production system. The purpose of virtual commissioning is to enable the control software, which controls and coordinates the different devices in a production station, to be tested and integrated in a virtual environment before the system is installed. However, there is still a gap between developing the control system and the earlier simulation activities. This thesis presents steps taken towards bridging this gap, by integrating virtual commissioning into the existing virtual preparation workflow. This is done by formalizing how the control system development can be performed, and enabling testing of logic related to the coordination of devices to be performed during the entire virtual preparation work. Furthermore, it is shown how existing preparation work for industrial robots can be brought into this formalized workflow to enable reuse and a gradual transition from traditional preparation methods into the proposed workflow. This is done by automatically generating models of how existing robot programs behave, which allows the coordination of them to be optimized, verified, and simulated within the proposed workflow. Lastly, it is demonstrated how virtual reality technology can be used in combination with virtual commissioning to perform testing of safety protocols by ``physically'' interacting with safety equipment and simulated human-machine interfaces.
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| 20. |
- Dahl, Martin, 1984, et al.
(författare)
-
Virtual Reality Commissioning in Production Systems Preparation
- 2017
-
Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - 1946-0740 .- 1946-0759. - 9781509065059
-
Konferensbidrag (refereegranskat)abstract
- Virtual commissioning (VC) is a method used to virtually visualize and test production systems, control logic and material flows. The focus of this paper is to further extend this concept using Virtual Reality (VR). The introduction of VR in VC enhances the concept by adding a more realistic visualization and movement tracking which extends the possibilities of its validation. The changes to the validation aspect are mainly due to the fact that it is now possible to interact with the running virtual production in a realistic and intuitive way. The interaction gives designers and operators a new possibility to go from being observers to actors in the design phase. They are now able to validate the production system, test security protocols and validate the human interaction with the system, using VR.
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| 21. |
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| 22. |
- Erös, Endre, 1990, et al.
(författare)
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Development of an Industry 4.0 Demonstrator Using Sequence Planner and ROS2
- 2021
-
Ingår i: Studies in Computational Intelligence. - Cham : Springer International Publishing. - 1860-9503 .- 1860-949X. ; 895, s. 3-29
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In many modern automation solutions, manual off-line programming is being replaced by online algorithms that dynamically perform tasks based on the state of the environment. Complexities of such systems are pushed even further with collaboration among robots and humans, where intelligent machines and learning algorithms are replacing more traditional automation solutions. This chapter describes the development of an industrial demonstrator using a control infrastructure called Sequence Planner (SP), and presents some lessons learned during development. SP is based on ROS2 and it is designed to aid in handling the increased complexity of these new systems using formal models and online planning algorithms to coordinate the actions of robots and other devices. During development, SP can auto generate ROS nodes and message types as well as support continuous validation and testing. SP is also designed with the aim to handle traditional challenges of automation software development such as safety, reliability and efficiency. In this chapter, it is argued that ROS2 together with SP could be an enabler of intelligent automation for the next industrial revolution.
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| 23. |
- Erös, Endre, 1990, et al.
(författare)
-
Evaluation of high level methods for efficient planning as satisfiability
- 2021
-
Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - 1946-0740 .- 1946-0759. - 9781728129891 ; 26
-
Konferensbidrag (refereegranskat)abstract
- Fast planning algorithms play a key role in intelligent automation systems where control sequences are constantly calculated. In order to determine which algorithms increase planning performance, we evaluate and compare several high level planning methods on a set of standard benchmarks. We focus on planning as satisfiability as the leading approach for solving difficult planning problems.
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| 24. |
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| 25. |
- Erös, Endre, 1990, et al.
(författare)
-
Towards compositional automated planning
- 2020
-
Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - 1946-0759 .- 1946-0740. ; 2020-September, s. 416-423
-
Konferensbidrag (refereegranskat)abstract
- The development of efficient propositional satisfiability problem solving algorithms (SAT solvers) in the past two decades has made automated planning using SAT-solvers an established AI planning approach. Modern SAT solvers can accommodate a wide variety of planning problems with a large number of variables. However, fast computing of reasonably long plans proves challenging for planning as satisfiability. In order to address this challenge, we present a compositional approach based on abstraction refinement that iteratively generates, solves and composes partial solutions from a parameterized planning problem. We show that this approach decomposes the monolithic planning problem into smaller problems and thus significantly speeds up plan calculation, at least for a class of tested planning problems.
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| 26. |
- Hanna, Atieh, et al.
(författare)
-
Industrial Challenges when Planning and Preparing Collaborative and Intelligent Automation Systems for Final Assembly Stations
- 2019
-
Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728103037 ; 2019-September, s. 400-406
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Konferensbidrag (refereegranskat)abstract
- During the last five decades, automation and robotics have transformed the automotive industry by increasing efficiency and improving the product quality. However, future trucks that will be autonomous, electrical and connected will require a completely new type of flexibility and intelligence in the production systems, especially in the final assembly. To handle the increased complexity of the products, production processes and logistic systems, final assembly must be transformed into collaborative and intelligent automation systems. These systems will include collaborative and deliberative robots (cobots), advanced vision-based control, adaptive safety systems, online optimization and learning algorithms and connected and well-informed human operators. But it will be a huge undertaking to transform current trucks industry such that they can design, implement and maintain large scale collaborative and intelligent automation systems. This paper presents the challenges with current planning and preparation processes for final assembly as well as the requirement and possible solutions for the future processes. An industrial use case at Volvo Trucks based on Sequence Planner and ROS2 is used to evaluate the proposed planning and preparation processes.
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| 27. |
- Yau, Y. Y. Y., et al.
(författare)
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Methane Emissions in Seagrass Meadows as a Small Offset to Carbon Sequestration
- 2023
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Ingår i: Journal of Geophysical Research - Biogeosciences. - : American Geophysical Union (AGU). - 2169-8953 .- 2169-8961. ; 128:6
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Tidskriftsartikel (refereegranskat)abstract
- Seagrass meadows are effective carbon sinks due to high primary production and sequestration in sediments. However, methane (CH4) emissions can partially counteract their carbon sink capacity. Here, we measured diffusive sediment-water and sea-air CO2 and CH4 fluxes in a coastal embayment dominated by Posidonia oceanica in the Mediterranean Sea. High-resolution timeseries observations revealed large spatial and temporal variability in CH4 concentrations (2-36 nM). Lower sea-air CH4 emissions were observed in an area with dense seagrass meadows compared to patchy seagrass. A 6%-40% decrease of CH4 concentration in the surface water around noon indicates that photosynthesis likely limits CH4 fluxes. Sediments were the major CH4 source as implied from radon (a natural porewater tracer) observations and evidence for methanogenesis in deeper sediments. CH4 sediment-water fluxes (0.1 +/- 0.1-0.4 +/- 0.1 mu mol m(-2) d(-1)) were higher than average sea-air CH4 emissions (0.12 +/- 0.10 mu mol m(-2) d(-1)), suggesting that dilution and CH4 oxidation in the water column could reduce net CH4 fluxes into the atmosphere. Overall, relatively low sea-air CH4 fluxes likely represent the net emissions from subtidal seagrass habitat not influenced by allochthonous CH4 sources. The local CH4 emissions in P. oceanica can offset less than 1% of the carbon burial in sediments (142 +/- 69 g CO2eq m(-2) yr(-1)). Combining our results with earlier observations in other seagrass meadows worldwide reveals that global CH4 emissions only offset a small fraction (<2%) of carbon sequestration in sediments from seagrass meadows. Plain Language Summary Seagrass meadows are hotspots for marine carbon storage in sediments. Part of the sediment carbon can be released as carbon dioxide and methane (CH4). Methane has 45-96 times more powerful global warming effect than carbon dioxide. If seagrass meadows release CH4, the emissions counteract their climate mitigation potential. We measured greenhouse gas concentrations and fluxes in a seagrass-dominated Mediterranean embayment. Low CH4 coincided with oxygen produced from seagrass photosynthesis. Areas with dense seagrass meadows had lower CH4 emissions. Overall, seagrass-dominated coasts were a small source of CH4 that offset only <2% of carbon buried in sediments on local and global scales. Hence, seagrass meadows remain an effective carbon sink.
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