Sitting on a gold mine: the story of the process industry's automatic formation of a digital twin

The use of a software tool chain to generate Digital Twins (DTs) automatically can speed up digitization and lower development costs. Engineering documents and system data are just two examples of source information that can be used to generate a DT. After proposing a general plan for semi-automatic generation of a DT for a process system, this work describe our efforts to extract necessary information for the generation of a DT of a process system from existing information in a factory floor like piping and instrumentation diagrams (P&IDs). To extract initial raw model data, techniques such as image, pattern, and text recognition can be used, and then an intermediate graph model can be generated and modified based on requirements. In order to increase the system's adaptability and reliability, this research will delve deeper into the steps involved in creating and manipulating an intermediate graph model

Efficacy of Low-Level Laser, Hard Occlusal Appliance and Conventional Pharmacotherapy in the Management of Myofascial Pain Dysfunction Syndrome; A Preliminary Study

Introduction:Myofascial pain dysfunction syndrome (MPDS) is a common temporomandibular joint disorder. Due to its multifactorial etiology, treatment usually involves more than one modality to obtain complementary results. The purpose of this study was to compare the combined effect of low level laser, hard occlusal appliance and conventional pharmacotherapy versus pharmacotherapy only in the management of patients with MPDS.Methods: In this randomized clinical trial, 15 MPDS patients were diagnosed and randomly assigned to 3 groups (n=5). Subjects in Group 1 were treated with pharmacotherapy (PT), Group 2 received active laser (940 nm Gallium Arsenide) every other day for a total of 10 sessions, plus pharmacotherapy (PTL) and Group 3 were given hard occlusal splint 12 h/day for 4 weeks plus pharmacotherapy (PTO). The intensity of pain was measured using visual analog scale (VAS) prior to treatment, 2 and 4 weeks after treatment onset and 2 weeks later. Maximum painless mouth opening and pain intensity at muscle palpation was also recorded. Comparisons were made between groups in 4 treatment sessions via repeated measure analysis of variance (ANOVA) (P < 0.05).Results: Pain relief, in subjective VAS was observed in both laser and appliance groups in the third and fourth examination sessions, though occlusal appliance significantly showed to provide the best results between the three groups (p<0.05). No statistically significant reduction in pain was noted using pharmacotherapy only. Maximum painless mouth opening and muscle tenderness was not significantly different among the three groups (p>0.05).Conclusion: Both Laser and occlusal appliance combined with pharmacotherapy proved to be effective for pain reduction. The 3 groups however failed to result in significant improvement in maximum mouth opening or tenderness of the muscles of mastication

Generating an industrial process graph from 3D pipe routing information

The automatic generation of digital twins of industrial processes requires the integration of several sources of information. If the twin is expected to accurately capture thermo-hydraulic phenomena, dimensions of tanks and other process components as well as detailed pipe routing information is relevant. Such information is not comprehensively captured in P&IDs (Piping & Instrumentation Diagrams), but it is available from 3D CAD models. However, information about control loops is not available from 3D CAD models, but is available from P&IDs. Previous research has demonstrated the extraction of such information from machine-readable P&IDs and 3D CAD models and converting this information to graphs. Further research is expected on applying graph matching methods for integrating these separate graphs to a common graph-based data structure that captures all of the desired information. This common model could support further work to develop digital twins. A major obstacle to this is that the graphs that have currently been generated from P&IDs and 3D CAD models are at very different abstraction levels, so graph matching methods are not feasible. This article address this obstacle by building on previous work, in which graphs were generated from P&IDs and 3D CAD models. The contribution of this paper is several novel algorithms for preprocessing a 3D CAD generated graph, until it is at the same level of abstraction as a P&ID generated graph of the same industrial process. The algorithms are demonstrated in the context of a laboratory process.Peer reviewe

Digital Twins for Manufacturing Using UML and Behavioral Specifications

Using digital twins, physical manufacturing objects can be virtualized and represented as digital models which are seamlessly integrated in both the physical and the digital space. This allows to simulate, verify and optimize production systems, from the logistical aspects to the manufacturing process and the involved components. A key challenge, in this area, is how to describe digital twins in complex manufacturing systems such that all physical details, processes, and verification needs are modeled at an appropriate and efficient abstraction level, e.g., modeling and detecting divers faults in production processes. To address this challenge, in this paper we present our work on modeling digital twins of manufacturing facilities using UML. UML class diagrams are used to describe static dependencies between entities, as well as to monitor and analyze the dynamic verification and quality aspects of manufacturing such as fault detection and consistency checks. Utilizing the key relevant features of UML in our approach, the designed class diagrams are used and enriched with behavioral models serving as digital twins which can be updated by live data from the manufacturing plant. We present a small example based on simulation programs and a demonstrator. The presented modeling approach and example provide useful insights to UML-based design of digital twins in complex manufacturing systems.Peer reviewe

Towards formal monitoring of workpieces in agile manufacturing

Information about the locations of objects is one of the main ingredients of Industry 4.0. With the increased use of flexible and agile manufacturing techniques, the monitoring of workpieces in a factory can become more challenging. In this paper, we present a state-machine-based approach for monitoring workpieces using sensors such as RFID readers. We present a solution where each object is represented as a deterministic state machine to monitor the object's journey throughout production via this state machine representation. Multiple objects can be monitored at the same time by running parallel event-based state machines. We present an implementation of our solution using RFID-Readers and OPC UA.Peer reviewe

Digital Twin-Assisted Controlling of AGVs in Flexible Manufacturing Environments

Publisher Copyright: © 2021 IEEE.Digital Twins are increasingly being introduced for smart manufacturing systems to improve the efficiency of the main disciplines of such systems. Formal techniques, such as graphs, are a common way of describing Digital Twin models, allowing broad types of tools to provide Digital Twin based services such as fault detection in production lines. Obtaining correct and complete formal Digital Twins of physical systems can be a complicated and time consuming process, particularly for manufacturing systems with plenty of physical objects and the associated manufacturing processes. Automatic generation of Digital Twins is an emerging research field and can reduce time and costs. In this paper, we focus on the generation of Digital Twins for flexible manufacturing systems with Automated Guided Vehicles (AGVs) on the factory floor. In particular, we propose an architectural framework and the associated design choices and software development tools that facilitate automatic generation of Digital Twins for AGVs. Specifically, the scope of the generated digital twins is controlling AGVs in the factory floor. To this end, we focus on different control levels of AGVs and utilize graph theory to generate the graph-based Digital Twin of the factory floor.Peer reviewe

Integrating 2D and 3D Digital Plant Information Towards Automatic Generation of Digital Twins

Ongoing standardization in Industry 4.0 supports tool vendor neutral representations of Piping and Instrumentation diagrams as well as 3D pipe routing. However, a complete digital plant model requires combining these two representations. 3D pipe routing information is essential for building any accurate first-principles process simulation model. Piping and instrumentation diagrams are the primary source for control loops. In order to automatically integrate these information sources to a unified digital plant model, it is necessary to develop algorithms for identifying corresponding elements such as tanks and pumps from piping and instrumentation diagrams and 3D CAD models. One approach is to raise these two information sources to a common level of abstraction and to match them at this level of abstraction. Graph matching is a potential technique for this purpose. This article focuses on automatic generation of the graphs as a prerequisite to graph matching. Algorithms for this purpose are proposed and validated with a case study. The paper concludes with a discussion of further research needed to reprocess the generated graphs in order to enable effective matching.Peer reviewe

Towards semi-automatic generation of a steady state digital twin of a brownfield process plant

Researchers have proposed various models for assessing design alternatives for process plant retrofits. Due to the considerable engineering effort involved, no such models exist for the great majority of brownfield process plants, which have been in operation for years or decades. This article proposes a semi-automatic methodology for generating a digital twin of a brownfield plant. The methodology consists of: (1) extracting information from piping and instrumentation diagrams, (2) converting the information to a graph format, (3) applying graph algorithms to preprocess the graph, (4) generating a simulation model from the graph, (5) performing manual expert editing of the generated model, (6) configuring the calculations done by simulation model elements and (7) parameterizing the simulation model according to recent process measurements in order to obtain a digital twin. Since previous work exists for steps (1–2), this article focuses on defining the methodology for (3–5) and demonstrating it on a laboratory process. A discussion is provided for (6–7). The result of the case study was that only few manual edits needed to be made to the automatically generated simulation model. The paper is concluded with an assessment of open issues and topics of further research for this 7-step methodology.Peer reviewe

Roadmap to semi-automatic generation of digital twins for brownfield process plants

Tallennetaan OA-artikkeli, kun julkaistu / KSIndustrial process plants have a lifecycle of several decades, and only some of the most modern plants have digital, machine-readable design information available. For all other plants, the information is often available in PDF and other human-readable formats. Based on this information, a digital twin could be constructed only with considerable human effort. There is a need for a methodology for the semi-automatic generation of digital twins for brownfields with such source information. The objective of this paper is to propose a roadmap towards a methodology for the semi-automatic generation of digital twins for brownfields with such source information as can be expected to be available for brownfields. The purpose of the roadmap is to: conceptualize the methodology, position relevant previous work along this methodology and identify further research challenges to develop the industrial applicability of the methodology. It was discovered that numerous relevant works exist, some of which do not specifically address brownfields. However, there is a lack of research to integrate such research to a methodology for the generation of digital twins.Peer reviewe

A Methodology for Generating a Digital Twin for Process Industry: A Case Study of a Fiber Processing Pilot Plant

Funding Information: This work was supported by Business Finland under Grant 3915/31/2019 and Grant 4153/31/2019. Publisher Copyright: © 2013 IEEE.Digital twins are now one of the top trends in Industry 4.0, and many companies are using them to increase their level of digitalization, and, as a result, their productivity and reliability. However, the development of digital twins is difficult, expensive, and time consuming. This article proposes a semi-automated methodology to generate digital twins for process plants by extracting process data from engineering documents using text and image processing techniques. The extracted information is used to build an intermediate graph model, which serves as a starting point for generating a model in a simulation software. The translation of a graph-based model into a simulation software environment necessitates the use of simulator-specific mapping rules. This paper describes an approach for generating a digital twin based on a steady state simulation model, using a Piping and Instrumentation Diagram (P&ID) as the main source of information. The steady state modeling paradigm is especially suitable for use casesinvolving retrofits for an operational process plant, also known as a brownfield plant. A methodology and toolchain is proposed, consisting of manual, semi-automated and fully automated steps. A pilot scale brownfield fiber processing plant was used as a case study to demonstrate our proposed methodology and toolchain, and to identify and address issues that may not occur in laboratory scale case studies. The article concludes with an evaluation of unresolved concerns and future research topics for the automated development of a digital twin for a brownfield process system.Peer reviewe