Methodology for evaluating the alignment of a multi-level CPPS digital twin

Background and objectives of the thesis

This thesis is part of the ANR Digital Twin for Cyber Physical Systems (DT4CPS, ANR-23-CE10-0010) project, which aims to federate the digital models of automation engineers and production engineers, turning them into fully-fledged digital twins for the commissioning of Cyber-Physical Production Systems (CPPS), but also a management support tool for Industry 4.0 actors.

CPPS (Cyber-Physical Production Systems) are systems made up of autonomous and collaborative entities with the computing capacity to interact with the physical world and make data available on the network.

There are a multitude of definitions of a digital twin (DT), depending on the use cases and associated value creation. The definition chosen for the DT will correspond to the vision of the automation engineer and the production engineer. The AIF (Alliance Industrie du Futur) has published a report on DT as a "major lever for the digital transformation of industry". DT is defined as:

• an organized set of digital models representing a realworld entity to address specific issues and uses,
• updated in relation to reality, with a frequency and precision adapted to its issues and uses,
• with advanced operational tools for understanding, analyzing, forecasting and optimizing the operation and management of the real entity.

In the DT4CPS project, the digital twin of a production system is considered to be multi-level: component level (automation engineer), equipment level (automation engineer / production engineer) and line level (production engineer). A calibration of the numerical simulation models making up this digital twin is necessary to align these numerical models with the physical twin, in order to give the digital twin a sufficiently similar behavior to its physical twin.

The scientific objectives of the thesis are therefore:

1. define indicators that characterize the alignment of a digital twin with respect to a physical twin;
2. on the basis of these indicators, define the gap deemed acceptable between the two twins for the intended use of the digital twin (if not, corrective action on the digital and/or physical twin will be necessary).  

From the point of view of DT usage, an "acceptable" alignment is a behavioral and temporal deviation that does not call into question the purpose of the decision.

Candidate profile

 The candidate must hold or be about to obtain a Master's degree or an engineering diploma at the time of application. The candidate should have skills in production systems, operations management and associated tools/software (flow simulation, MES, etc.), discrete-event systems, communication and data exchange between equipment. In addition, the successful candidate should have a keen interest in software development.

Missions

 Propose a methodology for evaluating the alignment of a multi-level digital twin to guarantee the intended uses of the digital twin at all times.

The main stages of the thesis will be:

• State of the art on the alignment and synchronization of a digital model with the entity being modeled (physical and software)
• Define relevant indicators to characterize the alignment of a digital twin with its physical twin
• Propose a methodology for measuring indicators of the alignment of a digital twin with its physical twin, considering different levels (from component level to production line level)
• Propose an approach for detecting deviations that require modification of one of the twins (with possible use of PLC and/or line reconfiguration techniques, in connection with another project thesis)

The proposed method will be tested on at least one automated line from one of the DT4CPS project partners and its digital twin.

Participation in national and international conferences and at least one publication in an international journal are expected. A good command of English is required.

Keywords

 Digital twin, alignment indicators, decision support, simulation, data processing, industry 4.0

Working environment

 Co-directed, the thesis will benefit from the working context of both the Quartz and DISP laboratories.

The thesis will be carried out in the Quartz laboratory. Travel to DISP will be required.

The Quartz laboratory is a multidisciplinary research unit dedicated to the engineering of complex systems. It is structured into six research teams covering a range of disciplinary and multidisciplinary scientific themes, focusing on : the vibratory and acoustic behaviour of structures ; the behaviour of materials under the severe stresses induced by operation and the consideration of non-linearities and geometric constraints in the context of analysing and optimising the behaviour of mechanical systems ; non-linear automation, power electronics, fast electronics, sustainable systems, renewable energy and mechatronics. The thesis will be carried out within the Sustainable Systems team. “Sustainable Systems” are complex products, systems or systems of systems. Sustainability may be linked to long life, use and/or the consideration of environmental indicators in the design, integration, reconfiguration and management of these systems. Research focuses on systems for the production of goods (automotive, aeronautics, cosmetics, etc.) and services (hospitals, urban transport and mobility, intelligent roads, etc.), supply chains, cyber-physical systems, and so on. It covers the various phases in the life cycle of these systems, from overall design to end-of-life, and is part of research fields such as "big data", "industry 4.0" and "smart and sustainable cities".

The DISP (Decision and Information Systems for Production system, UR4570) laboratory brings together researchers and teacher-researchers from the University of Lyon, with dual expertise in Industrial Engineering and Business Information Systems. In response to the scientific challenges posed by changes in the socio-economic world, it conducts research into the design and deployment of decision-support methods and information systems to improve the performance, agility and resilience of goods and services production systems and global supply chains. Its dual expertise, drawing on skills in Modeling, Operations Research, Simulation, Software Engineering, Artificial Intelligence, Planning, Scheduling and Decision Support, enables it to consider these complex systems in their technical, structural, organizational and human dimensions simultaneously. Its members are spread across 4 institutions of the University of Lyon: INSA Lyon, Université Lumière Lyon 2 and Université Claude Bernard Lyon 1, as the parent institutions, and Université Jean Monnet de Saint Etienne as a partner institution.

Application

 The application must include :

• A detailed CV
• A cover letter outlining your motivation for the thesis and your interest in research and doctoral studies.
• Grades from Master's program (M1, M2) or engineering school (L3, M1, M2) and any other documents deemed useful (letters of recommendation, for example)

After an initial selection process based on applications, the selected candidates will be interviewed by the thesis supervisors.

The thesis is scheduled to start in October 2024.

The gross monthly salary is 2,500 euros, plus a contribution towards transport and health insurance costs.

The thesis will be carried out in the Quartz laboratory. Travel to DISP will be required.

The Quartz laboratory is a multidisciplinary research unit dedicated to the engineering of complex systems. It is structured into six research teams covering a range of disciplinary and multidisciplinary scientific themes, focusing on : the vibratory and acoustic behaviour of structures ; the behaviour of materials under the severe stresses induced by operation and the consideration of non-linearities and geometric constraints in the context of analysing and optimising the behaviour of mechanical systems ; non-linear automation, power electronics, fast electronics, sustainable systems, renewable energy and mechatronics. The thesis will be carried out within the Sustainable Systems team. “Sustainable Systems” are complex products, systems or systems of systems. Sustainability may be linked to long life, use and/or the consideration of environmental indicators in the design, integration, reconfiguration and management of these systems. Research focuses on systems for the production of goods (automotive, aeronautics, cosmetics, etc.) and services (hospitals, urban transport and mobility, intelligent roads, etc.), supply chains, cyber-physical systems, and so on. It covers the various phases in the life cycle of these systems, from overall design to end-of-life, and is part of research fields such as "big data", "industry 4.0" and "smart and sustainable cities".

The DISP (Decision and Information Systems for Production system, UR4570) laboratory brings together researchers and teacher-researchers from the University of Lyon, with dual expertise in Industrial Engineering and Business Information Systems. In response to the scientific challenges posed by changes in the socio-economic world, it conducts research into the design and deployment of decision-support methods and information systems to improve the performance, agility and resilience of goods and services production systems and global supply chains. Its dual expertise, drawing on skills in Modeling, Operations Research, Simulation, Software Engineering, Artificial Intelligence, Planning, Scheduling and Decision Support, enables it to consider these complex systems in their technical, structural, organizational and human dimensions simultaneously. Its members are spread across 4 institutions of the University of Lyon: INSA Lyon, Université Lumière Lyon 2 and Université Claude Bernard Lyon 1, as the parent institutions, and Université Jean Monnet de Saint Etienne as a partner institution.

The candidate must hold or be about to obtain a Master's degree or an engineering diploma at the time of application. The candidate should have skills in production systems, operations management and associated tools/software (flow simulation, MES, etc.), discrete-event systems, communication and data exchange between equipment. In addition, the successful candidate should have a keen interest in software development.