A Survey of Industry Data Models and Reference Data Libraries
7 Metrology and simulation
7.1 Quality Information Framework (QIF)
7.1.1 Defining organization
Digital Metrology Standards Consortium (DMSC) defines the Quality Information Framework (QIF) standard. The QIF has been adopted as an ANSI standard
7.1.2 Objectives and scope
The “what is QIF?” webpage says:
QIF (Quality Information Framework) is an American National Standard supporting Digital Thread concepts in engineering applications ranging from product design through manufacturing to quality inspection. Based on XML, the QIF standard contains a Library of XML Schema ensuring both data integrity and data interoperability in Model Based Enterprise implementation.
The QIF covers quality information including measurement plans, results, part geometry and product manufacturing information, measurement templates, resources, and statistical analysis. The scope of QIF is shown in Figure 21.
Figure 21 - Scope of the QIF
7.1.3 Structure of the model
A simplification of the top structure is shown in Figure 22.
Figure 22 - The top of the QIF model
Comments on Figure 22:
- The QIF approach to the definition of an assembly is similar to that of ISO 10303, but differs in detail and uses different terminology.
- The documentation of the QIF envisages that a definition of a part can be provided by a digital model according to ISO 10303-242. It is curious that the definition of an assembly is not provided in the same way.
- ISO 10303-239 also considers both actual products and product designs. The way in which the actual and design are linked is not the same in the QIF.
The QIF contains XML schemas for geometry and topology. These are similar to the EXPRESS schemas in ISO 10303-42, but different in detail.
The QIF standard exists as an explanatory 563 page PDF document, and a set of XML schemas. No visualisation of the data architecture in UML or similar is provided.
Both ISO 10303-242 and the QIF are large and complicated. Working the two together must be a challenge for IT specialists.
7.1.5 Maintenance and usage
The QIF is actively maintained by a consortium of industrial users supported by NIST. The latest [in August 2020] edition of the QIF was published in December 2018.
Use of the QIF for metrology data is widespread.
7.2.1 Defining organization
OpenDrive is defined by ASAM (Association for Standardization of Automation and Measuring Systems) e.V., which is a non-profit organization that promotes standardization for tool chains in automotive development and testing.
ASAM e.V. is based in Germany.
7.2.2 Objectives and scope
The introduction to the OpenDrive standard says:
ASAM OpenDRIVE defines a file format for the precise analytical description of road networks. Unlike other file formats typically used for navigation systems, ASAM Open-DRIVE's main use is in the area of simulation applications, which require exact road geometry descriptions, including surface properties, markings, signposting and logical properties such as lane types and directions. Road data may be manually created from road network editors, conversion of map data, or originate from converted scans of real-world roads.
The OpenDrive standard also covers railway networks. OpenDrive is similar to many other data models that are created for analysis applications, however it has been included here because it is closely related to infrastructure description.
7.2.3 Structure of the model
The OpenDrive standard supports road geometry, as do the GIS applications, but with additional details about lane camber. The standard supports information about road surfaces to support vehicle dynamics simulation.
An interesting feature of the OpenDrive model is that it can hold detailed information about a road junction, as shown in Figure 23.
Figure 23 - OpenDrive paths through a road junction
Comments on Figure 23:
- The “connecting roads” are the allowed paths through the junction.
- Additional details can be provided about lanes and how they are marked out and connect, about tram lines, and about junction controls.
The OpenDrive standard is well documented, with explanations using UML and implementations using XML schema.
7.2.5 Maintenance and usage
The OpenDrive standard is actively maintained. The latest [in August 2020] edition of OpenDrive was published in March 2020.
Use of the OpenDrive for vehicle dynamics simulation is widespread.
7.3 Intelligent transport systems - Terminology
7.3.1 Defining organization
ISO/WD-TS 14812 “Intelligent transport systems - Terminology” is being defined by ISO TC 204 “Intelligent transport systems”.
7.3.2 Objectives and scope
No objectives or scope have been published by ISO, but the current deliverable is more than merely a terminology. Instead it is a UML model that has classes with natural language definitions. Where possible, the definitions are taken from other ISO standards.
There is detailed modelling of:
- vehicle automation, and Driver Automation Systems (ADS);
- roadways, road networks and junctions;
There is also a high-level model of Intelligent Transport Systems (ITS).
7.3.3 Structure of the model
The detailed modelling is represented in UML, and is easy to understand. As an example the models for vehicle component and vehicle automation are shown in Figure 24 and Figure 25.
Figure 24 - ISO 14812 model for vehicle components
Figure 25 - ISO 14812 model for vehicle automation
The top-level model for intelligent transport systems distinguishes between functional and physical views. The model contains the entities physical object, functional object and process. However the model is not easy to relate to the process industry system models in ISO 15926, MIMOSA CCOM or EPRI CIM. Neither is the terminology of ISO/IEC/IEEE 15288 “System life cycle processes” used.
The UML model was generated using the Enterprise Architect software, and is available as an Enterprise Architect native file or as an HTML view. The HTML view is adequate for review.
7.3.5 Maintenance and usage
The latest [in August 2020] version of the UML model is April 2020.
The standard is still under development, so there is no industrial usage.
7.4 ISO/IEC JTC 1 AHG 11 “Ad Hoc Group on the Digital Twin”
7.4.1 Defining organization
ISO/IEC JTC 1 AHG 11 “Ad Hoc Group on the Digital Twin” was formed in 2018 and produced the report “Data Architecture of the Digital Twin” (document ISO/IEC JTC 1 AHG 11 N0007) in July 2019.
7.4.2 Objectives and scope
The Scope clause of the report says:
This Ad Hoc Group is charged with:
- Defining the Digital Twin in order to establish common terminology across ISO/TC 184
- Drafting a proposed architecture concept of the Digital Twin
- Assessing the ISO/TC 184 portfolio of standards against the data architecture
- Propose an organizational structure to carry the work forward (Task Force, Working Group, etc.)
- Making recommendations to TC 184 based on the group’s work.
- The report does this, and notes the role of the ISO 23247 series of standards being developed under ISO TC 184/SC 4.
7.4.3 Structure of the model
7.4.5 Maintenance and usage
7.5 ISO/TC 184/WG 15 “Digital manufacturing”
7.5.1 Defining organization
ISO/TC 184/WG 15 “Digital manufacturing”
7.5.2 Objectives and scope
This working group has four standards under development, which are currently [in August 2020] at the DIS (Draft International Standard) stage:
ISO 23247-1 "Digital Twin framework for manufacturing — Overview and general principles"
ISO 23247-2 "Digital Twin framework for manufacturing — Reference architecture"
ISO 23247-3 "Digital Twin framework for manufacturing — Digital representation of manufacturing elements"
ISO 23247-4 "Digital Twin framework for manufacturing — Information Exchange"
These standards are at a high level and do not contain data models or reference data libraries.
7.5.3 Structure of the model
7.5.5 Maintenance and usage
7.6 Digital twin consortium
7.6.1 Defining organization
The website says:
Digital Twin Consortium is The Authority in Digital Twin. It coalesces industry, government and academia to drive consistency in vocabulary, architecture, security and interoperability of digital twin technology. It advances the use of digital twin technology from aerospace to natural resources.
Digital Twin Consortium is a global ecosystem of users who are accelerating the digital twin market and demonstrating the value of digital twin technology. Members set de facto technical guidelines and taxonomies, publish reference frameworks, develop requirements for new standards and share use cases to maximize the benefits of digital twins.
Digital Twin Consortium is open to any business, organization or entity with an interest in digital twins. Its global membership is committed to using digital twins throughout their operations and supply chains and capturing best practices and standards requirements for themselves and their clients.
The consortium has the same address as OMG.