Periodic Reporting for period 2 - DeFacto (Design Automation for Smart Factories)
Période du rapport: 2022-10-01 au 2023-09-30
These opportunities will come, however, with a series of engineering challenges. A smart manufacturing system must integrate a diverse set of components while offering strong guarantees in terms of functionality, reliability, safety, and cost. This heterogeneity in components and system requirements inevitably calls for models, specification formalisms, and design constraints of different nature to represent a design space that is difficult to extensively explore in a reasonable time, an issue that is often recognized as the "explosion in complexity" of today's industrial CPS design.
Mirroring the success of electronic design automation (EDA) in taming the complexity of microchip design in the '80s, system design automation is expected to play a crucial role in reducing the complexity of CPS design. The scientific goal of DeFacto is to advance the state of the art in system design automation by developing novel modeling paradigms, scalable algorithms, and tools to aid the design of smart manufacturing systems. DeFacto aims at automatically defining the architecture (i.e. the system components and their interconnections) and synthesizing the control software for the industrial CPSs that are part of smart manufacturing systems, ultimately fostering their widespread adoption. The methodologies developed in DeFacto reason about systems using reliable compositional abstractions of system behaviors based on assume-guarantee (A/G) contracts. Intuitively, an A/G contract represents the interface of a component as a pair of assumptions and guarantees. Assumptions are the behaviors that a component expects from the environment; guarantees are the behaviors the component promises in the context of the assumptions. Contracts are then mathematical models that provide rigorous composition rules and mechanisms to analyze complex system behaviors, validate the design requirements, and develop system components in a modular and hierarchical way. The project has three main research objectives:
- Objective 1: Identify requirements and architectures for the design of industrial CPSs and define contract-based representations for the requirements and the system components at different abstraction levels.
- Objective 2: Develop a formal methodology, algorithms, and computational tools for contract-based requirement validation, design-space exploration, and model refinement. The methodology refines the system-level requirements and maps them to a system architecture and a set of control algorithms.
- Objective 3: Develop synthesis and mapping algorithms to generate software implementations from higher-level models of the system architecture and the control algorithms. The implementations include monitors detecting undesired behaviors due to uncertainty in sensors, communication networks, and machine learning components.
SysML emerged as the most promising language for industrial cyber-physical systems (CPSs). This decision was based on understanding the interconnections among advanced manufacturing system requisites, system formalisms, and SysML diagrams. We developed a methodology for seamless reuse of system models and a SysML-centric strategy for system components and production recipes. The goal is to create models supporting advanced functionalities in cutting-edge manufacturing systems.
Our project aimed to address identified requirements, focusing on methodologies and tools supporting the formal design of industrial CPS. We advanced the theory of assume/guarantee contracts and introduced CHASE, a contract-based framework for exploring, analyzing, and optimizing CPS design space. We defined methodologies for validating and synthesizing discrete and stochastic systems and co-designing logistics systems, like automated warehouses.
We engineered a service-oriented manufacturing (SoM) architecture, modifying the automation pyramid, to improve data collection and increase the automation level of the systems. It enables data-driven autonomous execution, online optimization, and dynamic system reconfiguration. We developed methodologies for automated generation and deployment of software components, crucial for implementing the SoM paradigm, ensuring a smooth transition to autonomous manufacturing ecosystem.
Results were disseminated through articles at international conferences and tutorials at scientific venues in CPS, design automation, and computer engineering for manufacturing. Furthermore, part of the research led to creating a spin-off company.
The analysis of modeling and specification languages conducted in the project allowed us to identify the major drawbacks and limitations of the current approaches to modeling production systems. Subsequent research resulted in the definition of improved specification methods and the formulation of structured modeling methodologies. These methodologies enable holistic modeling, based on a single language (i.e. SysML), of features and requirements in a modern manufacturing system, thereby enhancing the organization of information used for designing, configuring, re-configuring, and managing production systems.
The automation software architecture developed in the project enables existing manufacturing systems to implement service-oriented manufacturing. Thus, making production systems more flexible and adaptable to market changes.