API-based Digital Twins - Architecture for Building Modular Digital Twins Following Microservices Architectural Style

Riku Ala-Laurinaho

API-based Digital Twins - Architecture for Building Modular Digital Twins Following Microservices Architectural Style

Julkaisun otsikon käännös: API-pohjaiset digitaaliset kaksoset

Riku Ala-Laurinaho

Energia- ja konetekniikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Neljäs teollinen vallankumous etenee nopeasti teollisuuden digitalisoitumisen kiihdyttämänä. Digitaalinen kaksonen on työkalu, joka tukee digitalisaatiota. Se tarjoaa useita ominaisuuksia, kuten huoltotarpeen ennustamista, simulaatioita, sekä laitteen käytönaikaista optimointia. Digitaalisen kaksosen ominaisuudet vaihtelevat paljon riippuen sen käyttökohteesta, ja yksinkertaisimmillaan digitaalinen kaksonen voi olla vain dokumentti, joka kuvaa tuotetiedot. Koska digitaaliset kaksoset ovat hyvin erilaisia, tarpeeksi yleisen arkkitehtuurin luominen on osoittautunut hankalaksi. Lisäksi nykyiset digitaalisten kaksosten arkkitehtuurit eivät hyödynnä jo olemassa olevia järjestelmiä täysimääräisesti digitaalisen kaksosen toteutuksessa. Tässä työssä kehitetään modulaarinen API-pohjainen (Application Programming Interface, sovellusrajapinta) arkkitehtuuri digitaalisille kaksosille sekä esitetään arkkitehtuurin käytännön toteutus siltanosturille. Tämä arkkitehtuuri tuo digitaalisen kaksosen tarjoaman tiedon saataville yhden rajapinnan kautta ja hyödyntää olemassa olevia järjestelmiä digitaalisen kaksosen toteutuksessa. Arkkitehtuurissa digitaalinen kaksonen koostuu erillisistä ohjelmistopalikoista, jotka toteuttavat sen ominaisuudet yhteistyössä. Jokainen näistä palikoista tarjoaa toiminallisuutensa palveluina API-rajapinnan kautta. Tämä API-rajapinta on liitetty Data Link -komponenttiin, joka välittää viestejä sekä näiden ohjelmistopalikoiden välillä että ohjelmistopalikoiden ja ulkoisten palveluiden välillä. Data Linkin käytännön toteutus on API-yhdyskäytävä, joka välittää viestit ohjelmistopalikoille noudattaen mikropalveluarkkitehtuuria. Mikropalveluarkkitehtuurissa jokainen ohjelmistopalikka toteuttaa yhden toiminnallisuuden eli tässä tapauksessa digitaalisen kaksosen ominaisuuden. API-pohjaisen arkkitehtuurin lisäksi tässä työssä tutkitaan Internet-rajapintoja teollisessa kommunikaatiossa. Tutkittuja REST- ja GraphQL-rajapintoja voidaan hyödyntää mikropalveluiden yhdistämisessä Data Link-komponenttiin. Tässä työssä arvioidaan myös Internet-rajapintojen soveltuvuutta OPC UA -palvelimelle, joka mahdollistaa kommunikaation teollisen laitteen ohjelmoitavan logiikan kanssa. Tässä työssä esitellään myös OSEMA (Open Sensor Manager, avoin anturienhallintajärjestelmä), joka mahdollistaa mittaukset digitaalisen kaksosen fyysisestä vastinparista. OSEMA mahdollistaa digitaalisen kaksosen pysymisen ajan tasalla sen fyysisestä kaksosesta. Sen avulla antureiden mittausasetuksia voidaan päivittää etänä Internetin yli. Lisäksi OSEMA pystyy luomaan anturille ohjelman sen asetuksiin perustuen, mikä helpottaa uusien anturien lisäämistä. Modulaarinen digitaalisten kaksosten arkkitehtuuri, Internet-rajapintojen vertailu sekä OSEMA tukevat osaltaan kehitystä kohti neljättä teollista vallankumousta ja teollisuuden digitalisaatiota.

Julkaisun otsikon käännös	API-pohjaiset digitaaliset kaksoset
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Tammi, Kari, Vastuuprofessori
Kustantaja	Aalto University
Painoksen ISBN	978-952-64-0593-3
Sähköinen ISBN	978-952-64-0594-0
Tila	Julkaistu - 2021
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

digitaalinen kaksonen
arkkitehtuuri
sovellusrajapinta
Teollisuus 4.0

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-64-0594-0

Siteeraa tätä

@phdthesis{68d9bfa10d0146718951f0d46d218ca3,

title = "API-based Digital Twins - Architecture for Building Modular Digital Twins Following Microservices Architectural Style",

abstract = "The Fourth industrial revolution drives the rapid digitalization of industry. Digital twin is an emerging tool for digitalization and offers various features, such as simulations, predictive maintenance, and optimization of operation. These features are highly use case dependent, and at simplest, a digital twin may only be a metadata document of the physical product. Because digital twins and their use cases vary greatly, creating an architecture that covers most of the digital twin features has been proven to be challenging. The digital twin features could be partly implemented using existing systems, but the current architectures do not employ these systems to the full extent. This dissertation proposes an Application Programming Interface (API)-based digital twin architecture for creating modular digital twins and presents a proof-of-concept implementation of the architecture for an overhead crane. The architecture enables using existing systems to implement digital twin and makes the digital twin data available from a single interface. In the API-based digital twin architecture, digital twins consist of separate software blocks that implement the features of digital twins and can work in collaboration. Each block offers its services via API that is accessed via Data Link. Data Link acts as a message broker between the blocks and makes their services available on the Internet. The practical implementation of the broker is an API gateway, which forwards HTTP (Hypertext Transfer Protocol) messages to software blocks. This API-based architecture follows microservices architectural style, in which each software block is responsible for implementing one feature of a digital twin. This study also compares Web APIs, REST (Representational State Transfer) and GraphQL, for industrial communication. These interfaces can be used to connect microservices to Data Link. In addition, the suitability of Web APIs for an additional interface to an OPC UA (Open Platform Communications Unified Architecture) server is investigated. OPC UA can provide access to an industrial machine PLC (Programmable Logic Controller) system. Finally, Open Sensor Manager (OSEMA) is presented as an enabler for data collection from a physical entity, which helps to keep a digital twin in sync with its counterpart. OSEMA allows remote software updates of sensors nodes and makes adding new ones easy by generating software based on the node configuration. In conclusion, this thesis presented a general API-based architecture for digital twins. The proposed architecture makes digital twin data accessible, provides a platform for creating advanced applications, and allows the use of existing systems to build digital twins. In addition, the architecture is flexible, modular, and scalable. This thesis also compared Web interfaces, which allow connecting microservices to Data Link, in industrial communication and presented one microservice for a digital twin. This service is Open Sensor Manager that facilitates keeping digital twin sync with its counterpart. These contributions aid in the digitalization of industry and accelerate the Fourth industrial revolution.",

keywords = "digital twins, cyber-physical systems, architecture, REST, API, GraphQL, Industry 4.0, digitaalinen kaksonen, arkkitehtuuri, sovellusrajapinta, Teollisuus 4.0, digital twins, cyber-physical systems, architecture, REST, API, GraphQL, Industry 4.0",

author = "Riku Ala-Laurinaho",

year = "2021",

language = "English",

isbn = "978-952-64-0593-3",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "159",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - API-based Digital Twins - Architecture for Building Modular Digital Twins Following Microservices Architectural Style

AU - Ala-Laurinaho, Riku

PY - 2021

Y1 - 2021

N2 - The Fourth industrial revolution drives the rapid digitalization of industry. Digital twin is an emerging tool for digitalization and offers various features, such as simulations, predictive maintenance, and optimization of operation. These features are highly use case dependent, and at simplest, a digital twin may only be a metadata document of the physical product. Because digital twins and their use cases vary greatly, creating an architecture that covers most of the digital twin features has been proven to be challenging. The digital twin features could be partly implemented using existing systems, but the current architectures do not employ these systems to the full extent. This dissertation proposes an Application Programming Interface (API)-based digital twin architecture for creating modular digital twins and presents a proof-of-concept implementation of the architecture for an overhead crane. The architecture enables using existing systems to implement digital twin and makes the digital twin data available from a single interface. In the API-based digital twin architecture, digital twins consist of separate software blocks that implement the features of digital twins and can work in collaboration. Each block offers its services via API that is accessed via Data Link. Data Link acts as a message broker between the blocks and makes their services available on the Internet. The practical implementation of the broker is an API gateway, which forwards HTTP (Hypertext Transfer Protocol) messages to software blocks. This API-based architecture follows microservices architectural style, in which each software block is responsible for implementing one feature of a digital twin. This study also compares Web APIs, REST (Representational State Transfer) and GraphQL, for industrial communication. These interfaces can be used to connect microservices to Data Link. In addition, the suitability of Web APIs for an additional interface to an OPC UA (Open Platform Communications Unified Architecture) server is investigated. OPC UA can provide access to an industrial machine PLC (Programmable Logic Controller) system. Finally, Open Sensor Manager (OSEMA) is presented as an enabler for data collection from a physical entity, which helps to keep a digital twin in sync with its counterpart. OSEMA allows remote software updates of sensors nodes and makes adding new ones easy by generating software based on the node configuration. In conclusion, this thesis presented a general API-based architecture for digital twins. The proposed architecture makes digital twin data accessible, provides a platform for creating advanced applications, and allows the use of existing systems to build digital twins. In addition, the architecture is flexible, modular, and scalable. This thesis also compared Web interfaces, which allow connecting microservices to Data Link, in industrial communication and presented one microservice for a digital twin. This service is Open Sensor Manager that facilitates keeping digital twin sync with its counterpart. These contributions aid in the digitalization of industry and accelerate the Fourth industrial revolution.

AB - The Fourth industrial revolution drives the rapid digitalization of industry. Digital twin is an emerging tool for digitalization and offers various features, such as simulations, predictive maintenance, and optimization of operation. These features are highly use case dependent, and at simplest, a digital twin may only be a metadata document of the physical product. Because digital twins and their use cases vary greatly, creating an architecture that covers most of the digital twin features has been proven to be challenging. The digital twin features could be partly implemented using existing systems, but the current architectures do not employ these systems to the full extent. This dissertation proposes an Application Programming Interface (API)-based digital twin architecture for creating modular digital twins and presents a proof-of-concept implementation of the architecture for an overhead crane. The architecture enables using existing systems to implement digital twin and makes the digital twin data available from a single interface. In the API-based digital twin architecture, digital twins consist of separate software blocks that implement the features of digital twins and can work in collaboration. Each block offers its services via API that is accessed via Data Link. Data Link acts as a message broker between the blocks and makes their services available on the Internet. The practical implementation of the broker is an API gateway, which forwards HTTP (Hypertext Transfer Protocol) messages to software blocks. This API-based architecture follows microservices architectural style, in which each software block is responsible for implementing one feature of a digital twin. This study also compares Web APIs, REST (Representational State Transfer) and GraphQL, for industrial communication. These interfaces can be used to connect microservices to Data Link. In addition, the suitability of Web APIs for an additional interface to an OPC UA (Open Platform Communications Unified Architecture) server is investigated. OPC UA can provide access to an industrial machine PLC (Programmable Logic Controller) system. Finally, Open Sensor Manager (OSEMA) is presented as an enabler for data collection from a physical entity, which helps to keep a digital twin in sync with its counterpart. OSEMA allows remote software updates of sensors nodes and makes adding new ones easy by generating software based on the node configuration. In conclusion, this thesis presented a general API-based architecture for digital twins. The proposed architecture makes digital twin data accessible, provides a platform for creating advanced applications, and allows the use of existing systems to build digital twins. In addition, the architecture is flexible, modular, and scalable. This thesis also compared Web interfaces, which allow connecting microservices to Data Link, in industrial communication and presented one microservice for a digital twin. This service is Open Sensor Manager that facilitates keeping digital twin sync with its counterpart. These contributions aid in the digitalization of industry and accelerate the Fourth industrial revolution.

KW - digital twins

KW - cyber-physical systems

KW - architecture

KW - REST

KW - API

KW - GraphQL

KW - Industry 4.0

KW - digitaalinen kaksonen

KW - arkkitehtuuri

KW - sovellusrajapinta

KW - Teollisuus 4.0

KW - digital twins

KW - cyber-physical systems

KW - architecture

KW - REST

KW - API

KW - GraphQL

KW - Industry 4.0

M3 - Doctoral Thesis

SN - 978-952-64-0593-3

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

API-based Digital Twins - Architecture for Building Modular Digital Twins Following Microservices Architectural Style

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

Sormenjälki

Siteeraa tätä