Function Block Model Research Articles

Co-clustering of multivariate functional data for the analysis of air pollution in the South of France

Nowadays, air pollution is a major threat for public health with clear relationships with many diseases, especially cardiovascular ones. The spatiotemporal study of pollution is of great interest for governments and local authorities when deciding for public alerts or new city policies against pollution increase. The aim of this work is to study spatiotemporal profiles of environmental data collected in the south of France (Région Sud) by the public agency AtmoSud. The idea is to better understand the exposition to pollutants of inhabitants on a large territory with important differences in term of geography and urbanism. The data gather the recording of daily measurements of five environmental variables, namely, three pollutants (PM10, NO2, O3) and two meteorological factors (pressure and temperature) over six years. Those data can be seen as multivariate functional data: quantitative entities evolving along time for which there is a growing need of methods to summarize and understand them. For this purpose a novel co-clustering model for multivariate functional data is defined. The model is based on a functional latent block model which assumes for each co-cluster a probabilistic distribution for multivariate functional principal component scores. A stochastic EM algorithm, embedding a Gibbs sampler, is proposed for model inference as well as a model selection criteria for choosing the number of co-clusters. The application of the proposed co-clustering algorithm on environmental data of the Région Sud allowed to divide the region, composed by 357 zones, into six macroareas with common exposure to pollution. We showed that pollution profiles vary accordingly to the seasons, and the patterns are similar during the six years studied. These results can be used by local authorities to develop specific programs to reduce pollution at the macroarea level and to identify specific periods of the year with high pollution peaks in order to set up specific health prevention programs. Overall, the proposed co-clustering approach is a powerful resource to analyse multivariate functional data in order to identify intrinsic data structure and to summarize variables profiles over long periods of time.

Functional non-parametric latent block model: A multivariate time series clustering approach for autonomous driving validation

Advanced driving-assistance systems validation remains one of the biggest challenges car manufacturers must tackle to provide safe driverless cars. The reliable validation of these systems requires to assess their reaction's quality and consistency to a broad spectrum of driving scenarios. In this context, large-scale simulation systems bypass the physical “on-tracks” limitations and produce important quantities of high-dimensional time series data. The challenge is to find valuable information in these multivariate unlabeled datasets that may contain noisy, sometimes correlated or non-informative variables. A new model-based tool is proposed for multivariate time series clustering based on a Bayesian co-clustering approach. The tool discriminates groups of correlated temporal variables, while modeling noise and providing probabilistic confidence interval for outlier detection. The proposed Functional Non-Parametric Latent Block Model (FunNPLBM) simultaneously creates a partition of observations and a partition of variables, using latent multivariate Gaussian block distributions. The model parameters follow a bi-dimensional Dirichlet Process as a prior for the block distribution parameters and for block proportions, and natively provides model selection. The method's capacities are illustrated with experiments and benchmarks on a simulated dataset and on an advanced driver-assistance system validation use-case.

IEC 61499 Device Management Model through the lenses of RMAS

Abstract The RMAS (relational-model multi-agent system) architecture has been proven promising towards the introduction of autonomic intelligence for industrial agents, and suitable for the enforcement of some parts of the reference model in the IEC 61499 standard, for distributed adaptive automation and control systems, namely the Resource model and the Function Block model. In this paper, the analysis is extended to the Device Management model. The RMAS is overlaid on the structures of this model in order to demonstrate that it can constitute factual and promising means for the expression of essential self-* capabilities of autonomic industrial agents. The analysis here conducted covers also some aspects of the XAI (explainable artificial intelligence), due to their relevance in industrial context. RMAS results a fundamental step for the factual introduction of AI in industrial playground, as a technology framework for the explainability, controllability, and quality of the intelligent automation solutions for industry.

Multi-Agent Modeling of Cyber-Physical Systems for IEC 61499 Based Distributed Automation

The traditional industrial automation systems developed under IEC 61131-3 in centralized control are statically programmed with determined procedures to perform predefined behaviors/tasks in structured environments. A major challenge for the traditional system is the frequent changes and constant uncertainties of the system itself, its operations and the operating environments. Therefore, in this paper we are trying to develop a two-layer architecture for modelling industrial cyber-physical systems, in which the multi-agent computing model is designed for the high-level architecture and the IEC 61499 function block model is applied for the low-level architecture. It aims to integrate system intelligence by communicating and computing cores from the high-level cyber modules and real-time adaptation by distributed and intelligent control of the low-level physical modules. The proposed modeling framework is tested for the feasibility study through preliminary experiments on Jetson Nano and Raspberry Pi by using agent modeling tool SPADE and function block modeling tool Eclipse 4diac.

The Functional Latent Block Model for the Co-Clustering of Electricity Consumption Curves

SummaryAs a consequence of recent policies for smart meter development, electricity operators nowadays can collect data on electricity consumption widely and with a high frequency. This is in particular so in France where the leading electricity company Électricité de France will be able soon to record the consumption of its 27 million clients remotely every 30 min. We propose in this work a new co-clustering methodology, based on the functional latent block model (LBM), which enables us to build ‘summaries’ of these large consumption data through co-clustering. The functional LBM extends the usual LBM to the functional case by assuming that the curves of one block live in a low dimensional functional subspace. Thus, the functional LBM can model and cluster large data sets with high frequency curves. A stochastic expectation–maximization–Gibbs algorithm is proposed for model inference. An integrated information likelihood criterion is also derived to address the problem of choosing the number of row and column groups. Numerical experiments on simulated and original Linky data show the usefulness of the methodology proposed.

Migration From PLC to IEC 61499 Using Semantic Web Technologies

This paper proposes a new methodology of migration from IEC 61131-3 PLCs to IEC 61499 function blocks. The aim of this migration process is to recreate IEC 61131-3 applications in IEC 61499 implementations with equivalent execution behavior. The formal model of the IEC 61131-3 standard for migration and cyclical execution model is defined. This method also creates a foundation for correct-by-design development tools and automatic migration between the IEC 61131-3 and IEC 61499 standard. Formal migration rules based on ontology mappings, restoring execution model including tasks and programs scheduling and variables mapping with different access levels, are provided. A transformation engine for importing PLC code, mapping from PLC ontology model to function block model and code generation is implemented based on the ontological knowledge base and semantic query-enhanced web rule language. The migration approach is demonstrated on a simple airport baggage handling system.

Interoperable CNC Machine via Function Block and STEP-NC Data Model for Milling Operation

The Function Block Development Kit (FBDK) platform proposed for STEP-NC controller architecture . It can be used to create an open CNC architecture on ISO 14649 and Function Block (IEC 61499). This offers interoperability, portability, and adaptability. The proposed framework consists of three main modules: (1) STEP-NC Interface, (2) Simulator, and (3) Communication. The system will be implemented in CNC controller on actual milling machine. It will simplify the design of CNC machine controller with the architecture layers responsible for data processing, data storage, execution and feedback. This paper also discusses towards the requirements for global interoperable manufacturing for real-life machining system with the architecture layers responsible for data storage, data processing, and execution.

The Design and Research of Cluster Router Based on ForCES Protocol

Cluster router is the trend of router development in the future, it enables every router in cluster to cooperate with each other very well. Besides, it greatly expands the capacity of router, and makes the network topology and routing strategies become simple and clear. This paper proposed a architecture based on Forwarding and Control Element Separation (ForCES) cluster, including control module and forwarding module, they are composed of a large number of PCs. The architecture solved the problem of the dynamic service deployment of Logical Function Block (LFB) model and so on, which is an evidence of improving the performance of the existing router by achieving the forwarding model.

Towards a Model-Driven IEC 61131-Based Development Process in Industrial Automation

The IEC 61131-3 standard defines a model and a set of programming languages for the development of industrial automation software. It is widely accepted by industry and most of the commercial tool vendors advertise compliance with it. On the other side, Model Driven Development (MDD) has been proved as a quite successful paradigm in general-purpose computing. This was the motivation for exploiting the benefits of MDD in the industrial automation domain. With the emerging IEC 61131 specification that defines an object-oriented (OO) extension to the function block model, there will be a push to the industry to better exploit the benefits of MDD in automation systems development. This work discusses possible alternatives to integrate the current but also the emerging specification of IEC 61131 in the model driven development process of automation systems. IEC 61499, UML and SysML are considered as possible alternatives to allow the developer to work in higher layers of abstraction than the one supported by IEC 61131 and to more effectively move from requirement specifications into the implementation model of the system.

Different perspectives [Face to Face; "IEC 61499 function block model: Facts and fallacies"

Different perspectives [Face to Face; "IEC 61499 function block model: Facts and fallacies"

The function block model in embedded control and automation from IEC61131 to IEC61499

The Function Block (FB) model was first standardized by the 1131 standard of the International Electrotechnical Commission (IEC) for programmable controllers. This standard was successfully adopted...

Automated Model Transformation between MATLAB Simulink/Stateflow and IEC 61499 Function Blocks

This paper presents a new method of modelling automation systems based on the combination and mutual transformation of Function Blocks of IEC 61499 and MATLAB Simulink/Stateflow. The ultimate goal of this development is to have a fully automated transformation between models built in the two platforms. The reasons for such transformation are due to the need for a proper validation environment for Function Blocks models and the difficulty in obtaining industrial acceptance in this new design approach. MATLAB Simulink/Stateflow provides a nice environment for modelling and simulation of control and embedded systems. Function Blocks are good for designing control application for complex physically distributed systems. An integrated software environment with transformation ability between these two tools will lead to a solution for the validation need for Function Blocks and also the adoption problems. This paper demonstrates a transformation practice where a Simulink model is transformed into a Function Block model in FBDK. The transformed model still requires some manual modifications to be executed because of the missing algorithm translation from MATLAB language to a language that can be used for algorithms in Function Blocks. This paper also discusses important issues of model transformation, such as semantics mapping, data type mappings and transformation rules.

Performance Analysis of a Real-Time Java Execution Environment for IEC 61499

The IEC 61499 standard enhances the 1131 Function Block model to exploit the advantages of the object technology in the industrial automation domain. Several prototype development environments have been developed by various research groups and the first commercial tools that support this model are already in the market. However, the absence of mature run-time environments that will allow the execution of IEC 61499 compliant applications is still evident. Even for the existing ones, there is no evidence about their efficiency to meet real-time constraints imposed by this kind of applications. Benchmarking of run-time environment is required to prove that these environments can be considered for the development of real-time applications. In this paper, a benchmarking framework is described and it is used to analyze the performance of an IEC 61499 run-time environment that is based on the real-time Java Specification. The recently released IBM and Sun RTSJ implementations are used to demonstrate the effectiveness of the RTSJ based framework. Performance results prove the applicability of the proposed run-time environment and the model driven approach that was adopted, in the control and automation domain.

Systematic Closed-Loop Modelling in IEC 61499 Function Blocks: A Case Study

In industrial automation, verification and validation using closed-loop plant-controller models is getting recognized as the way to verify the controller's logic and the resulting controlled object's behaviour. To tackle the issues preventing wide adoption of closed-loop verification, a model-integrated design framework supporting structural model development and verification has been recently proposed. This work presents a follow-up case study of the proposed model design methodology following the Model-View-Control design pattern to develop closed-loop models using IEC 61499 function blocks. In particular, this paper tries to identify and address the generic issues of closed-loop modelling and the issues specific to IEC 61499 function block model development.

An IEC61499-based development approach for distributed industrial control applications

The IEC61499 standard proposes the function block (FB) model for the next generation of distributed control applications. This model defines the FB type to be the basic construct in this paradigm. A control application is considered as a network of interconnected instances of FB types. These applications can be executed on one device such as a multitasking programmable logic controller (PLC), but they are usually executed on a network of interconnected devices. In this paper 1 , a methodology for the development and deployment of IEC61499-based control applications on a network of interconnected devices is proposed. The methodology is based on a hybrid approach that integrates the unified modelling language (UML) with the FB model; to semi automatically generate the design diagram in the form of a network of interconnected FB instances. A heuristic-based approach is described to allocate these instances to the execution environment, so as to satisfy constraints imposed by this kind of applications. A formal description of FB design models is proposed and a formal approach is described to assign FB instances to feasible OS tasks of devices while considering temporal constraints. A running example from industry is used to demonstrate the feasibility of the proposed approach.

A reconfigurable concurrent function block model and its implementation in real-time Java

This paper focuses on the important holonic manufacturing systems issue of automatic and dynamic adaptability to change at the physical machine level of control. We propose a model to support confi...

An agent-based approach to reconfiguration of real-time distributed control systems

We describe a general approach for dynamic and intelligent reconfiguration of real-time distributed control systems that utilizes the IEC 61499 function block model. This work is central to the development of distributed intelligent control systems that are inherently adaptable and dynamically reconfigurable. The approach that is used takes advantage of distributed artificial intelligence at the planning and control levels to achieve significantly shorter up-front commissioning times as well as significantly more responsiveness to change. This approach is based on object-oriented and agent-based methods, and aims at overcoming the difficulties associated with managing real-time reconfiguration of an intelligent manufacturing system.

A reconfigurable concurrent function block model and its implementation in real-time Java

This paper focuses on the important holonic manufacturing systems issue of automatic and dynamic adaptability to change at the physical machine level of control. We propose a model to support configuration and reconfiguration of real-time distributed

Network architecture for optical path transport networks

This paper proposes a new layered transport network architecture on which the WDM optical path network can be effectively created. The optical path network will play a key role in the development of the transport network that will realize the bandwidth-abundant B-ISDN. This paper extends the layered transport network architecture described in ITU-T Recommendation G.803 which is applied in existing SDH networks. First, we elucidate an application example of WDM optical path networks. Next, we propose a new layered architecture for WDM-based transport networks that retains maximum commonality with the layered architectures developed for existing B-ISDN networks. The proposed architecture is composed of circuit layer networks, electrical path layer networks, optical layer networks, and physical media (fiber) networks. The optical layer is divided into an optical path layer and an optical section layer. The optical path layer accommodates electrical paths. Optical section layer networks are divided into optical multiplex section (OMS) layer networks and optical repeater section (ORS) layer networks. The OMS layer network is concerned with the end-to-end transfer of information between locations transferring or terminating optical paths, whereas the ORS layer is concerned with the transfer of information between individual optical repeaters. Finally, a detailed functional block model of WDM optical path networks, the function allocation of each layer, and an optical transport module (OTM) are developed.