| 211. |
- Lager, Anders, et al.
(författare)
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A Task Modelling Formalism for Industrial Mobile Robot Applications
- 2021
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Ingår i: 2021 20th International Conference on Advanced Robotics, ICAR 2021. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665436847 ; , s. 296-303
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Konferensbidrag (refereegranskat)abstract
- Industrial mobile robots are increasingly introduced in factories and warehouses. These environments are becoming more dynamic with human co-workers and other uncertainties that may interfere with the robot's actions. To uphold efficient operation, the robots should be able to autonomously plan and replan the order of their tasks. On the other hand, the robot's actions should be predictable in an industrial process. We believe the deployment and operation of robots become more robust if the experts of the industrial processes are able to understand and modify the robot's behaviour. To this end, we present an intuitive novel task modelling formalism, Robot Task Scheduling Graph (RTSG). RTSG provides building blocks for the explicit definition of alternative task sequences in a compact graph format. We present how such a graph is automatically converted to a task planning problem in two different forms, i.e., a Mixed Integer Linear Program (MILP) and a Planning Domain Definition Language specification (PDDL). Converted RTSG models of a mobile kitting application are used to experimentally compare the performance of one MILP planner and two PDDL planners. Besides providing this comparison, the experiments confirm the equivalence of the converted MILP and PDDL problem formulations. Finally, a simulation experiment verifies the assumed correlation between a cost model, based on path lengths, and the makespan.
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| 212. |
- Lager, Anders, et al.
(författare)
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IoT and Fog Analytics for Industrial Robot Applications
- 2020
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Ingår i: The 25th International Conference on Emerging Technologies and Factory Automation ETFA2020.
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Konferensbidrag (refereegranskat)abstract
- The rapid development of IoT, cloud and fog computing has increased the potential for developing smart services for IoT devices. Such services require not only connectivity and high computing capacity, but also fast response time and throughput of inferencing results. In this paper we present our ongoing work, investigating the potential for implementing smart services in the context of industrial robot applications with focus on analytic inferencing on fog and cloud computing platforms. We review different use cases that we have found in the literature and we divide them into two suggested categories, "distributed deep models" and "distributed interconnected models". We analyze the characteristics of IoT data in industrial robot applications and present two concrete use cases of smart services where inferencing in a fog and a cloud architecture, respectively, is needed. We also reason about important considerations and design decisions for the development process of analytic services.
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| 213. |
- Lager, Anders, et al.
(författare)
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Task Roadmaps: Speeding up Task Replanning
- 2022
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Ingår i: Frontiers in Robotics and AI. - : Frontiers Media SA. - 2296-9144. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Modern industrial robots are increasingly deployed in dynamic environments, where unpredictable events are expected to impact the robot's operation. Under these conditions, runtime task replanning is required to avoid failures and unnecessary stops, while keeping up productivity. Task replanning is a long-sighted complement to path replanning, which is mostly concerned with avoiding unexpected obstacles that can lead to potentially unsafe situations. This paper focuses on task replanning as a way to dynamically adjust the robot behaviour to the continuously evolving environment in which it is deployed. Analogously to probabilistic roadmaps used in path planning, we propose the concept of Task roadmaps as a method to replan tasks by leveraging an offline generated search space. A graph-based model of the robot application is converted to a task scheduling problem to be solved by a proposed Branch and Bound (B&B) approach and two benchmark approaches: Mixed Integer Linear Programming (MILP) and Planning Domain Definition Language (PDDL). The B&B approach is proposed to compute the task roadmap, which is then reused to replan for unforeseeable events. The optimality and efficiency of this replanning approach are demonstrated in a simulation-based experiment with a mobile manipulator in a kitting application. In this study, the proposed B&B Task Roadmap replanning approach is significantly faster than a MILP solver and a PDDL based planner.
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| 214. |
- Lager, Anders, et al.
(författare)
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Task Roadmaps: Speeding Up Task Replanning : Corrigendum
- 2022
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Ingår i: Frontiers in Robotics and AI. - : Frontiers Media S.A.. - 2296-9144. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- In the original article, Listings 1 and 2 were not included during the typesetting process and were overlooked during production. The missing listings appear below.
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| 215. |
- Lager, Anders, et al.
(författare)
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Towards Reactive Robot Applications in Dynamic Environments
- 2019
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Ingår i: The 24th IEEE Conference on Emerging Technologies and Factory Automation ETFA2019. - 9781728103037 ; , s. 1603-1606
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Konferensbidrag (refereegranskat)abstract
- Traditionally, industrial robots have been deployed in fairly static environments, to perform highly dedicated tasks. These robots perform with very high precision and throughput. However, nowadays there is an increasing demand for utilizing robots in more dynamic environments, also performing more flexible and less specialized operations — high mix/low volume. Both traditional industrial robots and force-limited robots are used in collaborative, dynamic environments. Such robot applications introduce new challenges when it comes to efficiency and robustness. In this paper, we propose an architecture for reactive multi-robot applications in the context of dynamic environments, and we analyze the main research challenges that must be tackled for its realization. A logistics use case, with robots picking customer orders from the shelves of a warehouse, is used as a running example to support the description of the key challenges.
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| 216. |
- Lagou, Vasiliki, et al.
(författare)
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Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability
- 2021
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Differences between sexes contribute to variation in the levels of fasting glucose and insulin. Epidemiological studies established a higher prevalence of impaired fasting glucose in men and impaired glucose tolerance in women, however, the genetic component underlying this phenomenon is not established. We assess sex-dimorphic (73,089/50,404 women and 67,506/47,806 men) and sex-combined (151,188/105,056 individuals) fasting glucose/fasting insulin genetic effects via genome-wide association study meta-analyses in individuals of European descent without diabetes. Here we report sex dimorphism in allelic effects on fasting insulin at IRS1 and ZNF12 loci, the latter showing higher RNA expression in whole blood in women compared to men. We also observe sex-homogeneous effects on fasting glucose at seven novel loci. Fasting insulin in women shows stronger genetic correlations than in men with waist-to-hip ratio and anorexia nervosa. Furthermore, waist-to-hip ratio is causally related to insulin resistance in women, but not in men. These results position dissection of metabolic and glycemic health sex dimorphism as a steppingstone for understanding differences in genetic effects between women and men in related phenotypes.
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| 217. |
- Leander, Björn, 1978-, et al.
(författare)
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Dependability and Security Aspects of Network-Centric Control
- 2023
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Ingår i: IEEE Int. Conf. Emerging Technol. Factory Autom., ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9798350339918
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Konferensbidrag (refereegranskat)abstract
- Industrial automation and control systems are responsible for running our most important infrastructures, providing electricity and clean water, producing medicine and food, along with many other services and products we take for granted. The safe and secure operation of these systems is therefore of great importance.One of the emerging trends in industrial automation systems is the transition from static hierarchical controller-centric systems to flexible network-centric systems. This transition has a great impact on the characteristics of industrial automation systems. In this article we describe the network-centric design strategy for industrial automation systems and describe the impact on dependability and security aspects that this strategy brings, looking at both challenges and possibilities.
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| 218. |
- Lindgren, M., et al.
(författare)
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Applicability of using internal GPGPUs in industrial control systems
- 2014
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Ingår i: 19th IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2014. - 9781479948468 ; , s. Article number 7005096-
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Konferensbidrag (refereegranskat)abstract
- Industrial control systems are continuously increasing in functionality, connectivity, and levels of integration, and as a consequence they require more computational power. At the same time, these systems have specific requirements related to cost, reliability, timeliness, and thermal power dissipation, which put restrictions on the hardware and software used. Today the high-end embedded CPUs not only provide multiple cores, but also integrated graphics processors (GPU) at close to no additional cost. The use of GPUs for general processing have several potential values in industrial control systems; 1) the added computational power and the high parallelism could pave way for new functionality and 2) the integrated GPU could potentially replace other hardware and thereby reduce the overall cost. In this paper we investigate the applicability of using integrated GPUs in industrial control systems. We do this by evaluating the performance of GPUs with respect to computational problem types and sizes typically found in industrial control systems. In the end we conclude that GPUs are no obvious match for industrial control systems and that several hurdles remain before a wide adoption can be motivated.
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| 219. |
- Liu, Meng, et al.
(författare)
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A dependency-graph based priority assignment algorithm for real-time traffic over NoCs with shared virtual-channels
- 2016
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Ingår i: IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS. - 9781509023394
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Konferensbidrag (refereegranskat)abstract
- The Network-on-Chip (NoC) is the on-chip interconnection medium of choice for modern massively parallel processors and System-on-Chip (SoC) in general. Fixed-priority based preemptive scheduling using virtual-channels is a solution to support real-time communications in on-chip networks. Targeting the priority assignment problem in the context of NoCs, heuristic based priority assignment algorithms are more practical, due to the exponentially increased search space as the number of flows goes up. In our previous work, we have proposed a graph-based heuristic priority assignment algorithm (called GHSA) for NoC communications, where we show that taking the dependencies between flows into account can significantly reduce the search space. However, GHSA only works for NoCs with distinct priorities. Routers in such type of platforms may have a large amount of buffer cost when the number of flows is high. The applicability can thus be limited in reality. One solution to reduce the buffer cost is to allow priority sharing of different flows. In this paper, we propose a dependency-graph based priority assignment algorithm (called eGHSA) targeting NoCs with shared virtual-channels. A number of experiments as well as a case study based on an automotive application are generated, which clearly show that eGHSA improves the efficiency compared to the existing solution in the literature.
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| 220. |
- Liu, Meng, et al.
(författare)
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A Server-based Approach for Overrun Management in Multi-Core Real-Time Systems
- 2014
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Konferensbidrag (refereegranskat)abstract
- This paper presents a server-based framework for task overrun management in multi-core real-time systems. Unlike most existing scheduling methods which usually assume a single upper bound of the Worst-Case Execution Time (WCET) for each task, our approach targets scenarios with task overruns. The main idea of our framework is to employ Synchronized Deferrable Servers (SDS) to deal with globally scheduled task overruns, while a partitioned scheduling approach is applied on regular task executions. Moreover, we provide a deterministic Worst- Case Response Time (WCRT) analysis focusing on hard timing constraints, along with a probabilistic analysis of Deadline Miss Ratio (DMR) for soft real-time applications. In the evaluation phase, we have implemented two types of experiments evaluating different timing constraints.
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