This paper proposes a novel AI agent for reasoning, planning, and testing industrial automation applications. The AI agent accepts operator instructions in natural language and performs semantic reasoning over functional requirements to generate an optimized cost-effective action plan. This plan comprises a sequence of executable actions that can be deployed in industrial control systems (ICS) to enable efficient and sustainable machine operation. Then the AI agent automates the testing of control systems by comparing the agent’s planned and executed actions against expected outputs, ensuring requirement conformance and enhancing system reliability. Experimental results demonstrate the effectiveness of the AI agent in generating sustainable operational plans and validating control system behavior for laboratory scale case studies, underscoring its potential in the future of intelligent industrial automation.

This paper presents the Function Block Assistant (fbAssistant), an LLM-backed tool prototype for developing control logic in industrial automation. fbAssistant interprets natural language requirements and automatically generates state machines and their function blocks implementation. The study demonstrates iterative refinement, simulation validation, and deployment using EcoStruxure Automation Expert. The proposed approach aims at improved efficiency and accuracy in the development of automation software.

This paper introduces an innovative multiactor framework that harnesses the potential of LLMs to augment the functionalities of ICS. By integrating conversational AI technologies, this framework significantly improves human-machine interactions, enabling sophisticated analysis and visualization of intricate data sets. The core of the system comprises specialized LLM actors that interact through a LangGraph-based multiactor framework, addressing various aspects of IEC 61499 control systems including PLC code analysis, SQL query execution, and data visualization. This integration enables operators to interact with the control system using natural language, significantly reducing technical barriers and enhancing the accessibility and usability of complex industrial systems.

IEC 61499 is an executable, event-based language for control software that allows visual and textual implementation of individual software components (Function Blocks, FBs). The standardized visual service sequence model specifies the expected input/output behaviour of a component, thus supporting model-based testing. We present our approach for testing an FB on various platforms, which helps manage the variations in execution semantics between different vendors. First, service sequences are generated manually or derived from an existing (partial) implementation. Then, these service sequences serve as unit tests for this implementation. Finally, we create a test application that is executable on any IEC 61499-compliant platform. Executing tests directly in the target platform helps validate the correct functionality of an FB before deploying the control software to a cyber-physical system.

A learning management system (LMS) is a web-based technology developed to improve the learning process in educational institutions. This study addresses the drawbacks of existing LMS by developing DeLMS (Decentralized Learning Management System) and aims to revolutionize the way educational institutions manage and deliver educational content using Ethereum smart contracts and the IPFS (InterPlanetary File System). By leveraging Smart contracts and IPFS cutting-edge technologies, DeLMS provides a secure, transparent and decentralized platform for managing and delivering educational content. The content addressing feature of IPFS eliminates the need for constant requests to centralized servers for the location of files, resulting in faster file transfer and reduced energy consumption. The proposed system has the potential to change the way educational institutions operate, making it more accessible and beneficial for both students and educators.

In this paper, we describe a method to automatically derive the controller for an automated process by an interactive learning approach using a simulation model developed in Visual Components 3D simulation software. The latter is used to record the events of the processes and the controller is generated as an IEC 61499 function block. To create different process scenarios, the actuator signals are triggered manually in appropriate order. The controller logic in Petri net is derived by process discovery algorithms with help of recorded events and conversion of Petri net to IEC 61499 function blocks is done by a software tool configured with a set of transformation rules.

Arrowhead Tools

With increase in use formal verification tools and methods in distributed systems, it is becoming more challenging to analyse the execution traces generated by formal verification tools. This paper presents a method for unification of execution traces of industrial automation systems, based on IEC 61499 standard. Execution trace of a system is a sequence of events, where each event represents a change in the state of the system. Execution traces allow developers to explore safely behavior of control software. Execution traces can be obtained several ways, including monitoring of a real system (or its simulator), or as a counterexample build by model checker. In the paper we explore unification of execution traces for debug task in FBME - modular IDE for IEC 61499 applications. We present the formal model of the execution trace representation and show the working on a simple example.

In this paper, we discuss how process mining techniques can be applied in industrial control systems for modeling, verification, and enhancement of the cyber-physical system based on recorded data logs. Process mining is used for extracting the process models in different notations from the recorded behavioral traces of the system. The output model of the system’s behavior is mainly derived using an open-source tool called ProM. The model can be used for such applications as anomaly detection, detection of cyber-attacks and alarm analysis in industrial control systems with the help of various control flow discovery algorithms. The extracted process model can be used to verify how the event log deviates from it by replaying the log on Petri net for conformance analysis.

This paper reports on a method of automatic generation of a formal model of plant from the behaviour traces recorded from its digital twin. The traces are observed from simulation in the loop of the digital twin in Visual Components connected with distributed automation software, developed in NxtSTUDIO according to IEC 61499. The generated modular formal model of the closed-loop system is transformed to the model of uncontrolled plant behaviour extended with nondeterminism. The model is then combined in closed-loop with the formal model of controller, generated from its source code using the fb2smv tool. The verification and simulation is done by the symbolic model checker NuSMV tool, which verifies various CTL/LTL specifications of the system.

This paper introduces a problem-oriented notation within the IEC 61499 syntax to be used for creating formal closed-loop models of cyber-physical automation systems. The proposed notation enables creation of a comprehensive tool-chain that can combine design, simulation, formal verification and distributed deployment of automation software. The proposed notation allows for definition of non-deterministic transitions in ECC of basic function blocks of IEC 61499.The tool chain includes an IEC 61499 compliant engineering environment, fb2smv converter of functions blocks to SMV code, the NuSMV model-checker and utilities for interpreting counterexamples.

This paper reports on integration of the Industrial Internet of Things (IIoT) service framework Arrowhead with automation systems programmed in the traditional and future automation languages. In particular it focuses on integrating the Arrowhead Datamanager system into the Eclipse 4DIAC IEC 61499 development environment and testing it on a physical system plant.

Nowadays an increasing number of industries are considering moving toward being Industry 4.0 compliant. But this transition is not straightforward: transfer to new system can lead to significant production downtime, resulting in delays and cost overruns. The best way is systematic seamless transition to newer and advanced technologies that Industry 4.0 offers. This article proposes a framework based on automatic synthesis methods that learns the behavior of an existing legacy programmable logic controller (PLC) and generates state machines that can be incorporated into IEC 61499 function blocks. Proposed algorithms are based on Boolean satisfiability (SAT) solvers. The first algorithm accepts a set of noisy PLC traces and produces a set of candidate state machines that satisfy the traces. The second algorithm accepts error-free traces and synthesizes a modular controller that may be distributed across several physical devices. The toolchain architecture is exemplified on a laboratory scale Festo mechatronic system.

The growing need for smart and flexible systems in many areas of industry, such as manufacturing, smart grids, building automation systems and others, has resulted in new design approaches such as Cyber-physical systems (CPS). This raised the need for formal modelling of these systems to address reliability and robustness requirements. This paper addresses the problem of developing a formal semantics, based on abstract state machines (ASM), for modelling of distributed control systems for industrial CPS based on the IEC 61499 standard. The developed approach allows to build formal models of flexible distributed control systems for analysis and verification of various properties.

Daedalus is conceived to enable the full exploitation of the CPS' virtualized intelligence concept, through the adoption of a completely distributed automation platform based on IEC-61499 standard, fostering the creation of a Digital Ecosystem that could go beyond the current limits of manufacturing control systems and propose an ever-growing market of innovative solutions for the design, engineering, production and maintenance of plants' automation.

Today, more and more industries are considering moving towards being Industry 4.0 compliant. But this transition is not straightforward due to many reasons: in particular, transfer to new system can lead to significant production downtime and could result in delays and cost overruns. The best way is systematic seamless transition to newer and advanced technologies that Industry 4.0 offers. This paper proposes an automated synthesis framework that learns the behavior of existing legacy and often black-box programmable logic controllers and generates state machines that can be incorporated into IEC 61499 function blocks. The paper presents the toolchain architecture and exemplifies it on a laboratory scale Festo didactic mechatronic system.

Industrial automation systems (IAS) need to be highly dependable; they should not merely function as expected but also do so in a reliable, safe, and secure manner. Formal methods are mathematical techniques that can greatly aid in developing dependable systems and can be used across all phases of the system development life cycle (SDLC), including requirements engineering, system design and implementation, verification and validation (testing), maintenance, and even documentation. This state-of-the-art survey reports existing formal approaches for creating more dependable IAS, focusing on static formal methods that are used before a system is completely implemented. We categorize surveyed works based on the phases of the SDLC, allowing us to identify research gaps and promising future directions for each phase.

This paper presents initial results on formal verification of protection functions in a smart power distribution grid. Informal properties of the smart grid were formalized in the language of LTL and formal verification is performed using NuSMV model checker on the closed-loop plant-control model which consists of IEC 61499-based control logic and an abstract plant model of distribution grid with fault scenario. The paper presents the results of verification of dependability, liveliness, safety and security properties. The results show the effectiveness of the closed-loop formal verification methodology.

Design patterns in software engineering is a generic solution provided for repeatable problems occurring frequently in a software design. They are used a lot in the field of software engineering, especially for object-oriented software development. Different standards exist for design and development of industrial cyber-physical systems and the IEC 61499 standard is one of them. The standard presents a reference component architecture for design and development of distributed industrial cyberphysical systems. There is a lack of design patterns for application development with IEC 61499 standard and this paper address this by proposing some patterns. The design patterns presented are inspired by popular design patterns used in software engineering.

Cyber-physical agnosticism (CPA) is a property of software in cyber-physical systems (CPS) to withstand various disturbances and keep maintaining the required behaviour of the physical process. With the increased research on the use of internet of things (IoT) in industrial automation (IoT-A), there is a need for robust distributed automation control systems that can take into account some overheads of using wireless devices in such an IoT setup. For example, data transfer delays between wireless sensors and the controller might result in the controller acting on a stale sensor value. In this paper, we present an approach of using time-aware computations to let the controller to assess quality of the input data and formal verification as a method to check the CPA property of the IoT-A applications. The paper specifically considers IEC 61499 standard for implementation of distributed IoT-A application. Ptolemy II PTIDES inspired time stamped event semantics is used in the application to keep track of the origin of different events. Timed automata are used to model the plant. The IEC 61499 application together with abstract plant model is then converted to SMV language and NuSMV model checker is used for formal verification. The paper presents a case study of an elevator example to demonstrate the proposed approach. A random delay is used to model the communication delay in the wireless network. It is shown that if the communication delay was not accounted for, then the elevator would stop in-between the floors and open the doors that is considered unsafe. The paper then shows how time-aware computation is used to make sure that the elevator always follows safe behaviour.

An approach for automatic reconstruction of automation logic from execution scenarios using a metaheuristic algorithm is proposed. IEC 61499 basic function blocks are chosen as implementation language and reconstruction of Execution Control Charts for basic function blocks is addressed. The synthesis method is based on a metaheuristic algorithm that combines ideas from ant colony optimization and evolutionary computation. Execution scenarios can be recorded from testing legacy software solutions. At this stage results are only limited to generation of basic function blocks having only Boolean input/output variables.

This paper presents a novel approach to automation of flexible manufacturing systems with mechatronic intelligence and distributed control. The mechatronic intelligence layer is implemented using a combination of wireless sensor/actuator networks with service-oriented architecture, where services are located at the device level, as well as in local and global Clouds following the Arrowhead framework.

The protection system is a crucial part of the power grid. It protects people, equipment, and property. Reliability of such mission critical systems is of an extreme importance. Protection systems have strict requirements to reliability including dependability, security and timeliness. Although it undertakes rigorous testing and commissioning, it fails in some circumstances causing faults in the network, resulting in loss of power. It is hard to catch these hidden and undetectable errors in the design and installation. Since protection function is essentially a piece of code, formal methods can be used for rigorous testing of the software and provide definitive proof of the system properties. This paper proposes a formal model (to use in formal verification techniques) for protection systems. The paper develops closed loop model of the electrical network with its protection system. The model is developed in IEC 61499 language for the further generation of its formal model in SMV language. The model is validated via simulation and comparison with a comprehensive model of the electrical network in Matlab Simulink. In future work, the generated SMV model will be used to formally verify reliability requirements of the protection system.

This paper presents a model-checking framework for the purpose of design and implementation of robust smart grid applications based on distributed intelligence. The paper first introduces distributed grid intelligence approach to smart grid automation and related challenges of their verification. We then introduce the case study example and how model-checking can be applied to the presented system implemented in IEC 61499 standard. In the end we present the initial results of our model-checking application to smart grid applications. The paper will conclude with some issues faced during the research and corrective steps to address these issues in future.

Requirements engineering is the first stage in the development of any system. For safety-critical industrial systems like smart-grids, we must ensure that requirements are properly elicited, defined, analyzed and managed. This paper adapts the requirements framework developed in the CESAR European project, called the CESAR requirements meta-model, to support all aspects of requirements engineering for safety-critical systems. This enables the formalization of requirements in order to automate and assist in many aspects of later stages in the system development life cycle. Using a smart grid system from the FREEDM project, we illustrate that the adapted requirements engineering framework is comprehensive and rich for large safety-critical systems. We find that the use of the IEC 61499 function block standard provides an appropriate system modelling and implementation framework, which complements the strengths of the proposed requirements engineering framework. Traceability links between requirements and components of an IEC 61499 system model can help with automatic test case generation and formal analysis of requirements.

This paper presents an approach for automatic reconstruction of automation logic from execution scenarios using a metaheuristic algorithm. The IEC 61499 basic function blocks is chosen as implementation language and reconstruction of Execution Control Charts for basic function blocks is addressed. The synthesis method is based on a metaheuristic algorithm most closely related to ant colony optimization and evolutionary computation. Execution scenarios can be recorded from testing legacy software solutions. At this stage results are only limited to generation of basic function blocks having only Boolean input/output variables.

This paper proposes a framework for formal verification of industrial automation software in an intuitive way. The IEC 61499 function block architecture is assumed to be the input language, and the Intelligent Mechatronic Components (IMC) architecture is assumed as an underlying design pattern for the applications, which implies autonomous control logic in each IMC and their compositions to systems in a plug-and-play way. Then the system is automatically verified using model checking and the counter examples for the failed model checking properties are played back step-by-step and state-by-state in the simulation model that most industrial automation control systems would have built as the basis for initial testing. Net Condition Event Systems formalism (a modular extension of Petri net) is used to model the decentralized control logic and discrete-state dynamics of the plant. The model is then subjected to model checking using the ViVe/SESA tool chain. The method's application is illustrated using a simple pick and place manipulator. A closed loop model of Plant and Controller is used. Controller is extensively verified for safety, liveliness and functional properties of the robot. We then show how a counter example for deadlock detected by the model checker is played back in the simulation model for visualizing how exactly the system deadlocked.

This paper proposes a new software composition method for automated machines that exploits their mechatronic modularity. It is demonstrated that desired behavior of a certain class of machines can be composed of behaviors of its mechatronic components, including fully decentralized scheduling and operation control. This aims at increased performance of software design and maintenance, as well as systems' flexibility and reconfigurability. The IEC 61499 Function Blocks' (FBs) architecture is used as an implementation platform that enables system-level simulation and transparency of deployment. A configurable pick-and-place (PnP) manipulator with decentralized control synthesized using the proposed approach is chosen as an illustrative example.

This paper presents a feasibility study of implementing parts of a distributed function block application as TinyOS modules running on Wireless Sensors as a part of Wireless Sensor Network. The paper first briefly describes underlying technologies and gives motivation for implementation of function blocks in TinyOS. The paper then presents implementation details about TinyOS realization of the one of the function block, which is a part of bigger distributed control application with the help of distributed function block application.

The second edition of the IEC 61499 standard aims to clarify the interpretation ambiguities of function block's execution semantics. This resolves the pivotal issue of realizing portable and interoperable implementations of the IEC 61499 reference architecture. As the IEC 61499 standard is about entering its technology takeoff phase, these clarifications are timely and important. It is hence expected that more innovators of automation software tools, runtime environments, and control hardware will start adopting this technology. To assist such adoption, this paper presents a study of existing IEC 61499 tools' portability issues. In particular, the features of currently active IEC 61499 tools, such as FBDK, ISaGRAF, 4DIAC, and nxtStudio are outlined. Their incompatibility issues due to different execution semantics are exemplified. Moreover, it is also illustrated in this paper how these issues can be addressed by complying with the updated norms.

This paper presents a practical framework to bring the cyber-physical block diagram models, such as Ptolemy, to the practice of industrial automation. Cyber-Physical Component (CPC) architecture is suggested. CPC aims at the improvement of design, verification and validation practices in automation of Smart Grid. IEC 61499 standard is used as a basis for this architecture. This architecture addresses several design software and system engineering challenges: right equilibrium between abstract representation and “executability” and round-trip engineering. An CPC exhibit such properties as portability, interoperability and configurability thanks to the reliance on open standards. The use of time stamp based execution paradigm adds determinism and predictability at the run-time.

Interoperability is one of the most important features expected from distributed automation architectures. Achieving interoperability involves addressing issues related to synchronization of behavior, communication protocols, and data presentation formats. In this paper a case study on deployment of an automation application to a network of control devices with three different hardware/software platforms is presented to exploit benefits of the IEC 61499 architecture. Firstly, an overall control application with essentially distributed logic was created. This control application was then validated using closed-loop simulation and finally deployed to a network of control devices.

This paper presents implementation of one of the Distributed Grid Intelligence (DGI) applications: Load Balancing, using the IEC61499 architecture. This enables system level design of distributed load balancing application with a direct pathway to deployment to hardware. The use of IEC 61499 improves scalability, re-configurability and maintainability of automation software. The application was deployed to commercial programmable automation devices and embedded controller (ARM based TS-7800). The application was verified using co-simulation approach: control and power system simulated using Matlab on PC networked with the number of distributed hardware running load balance algorithm. The use of IEC 61499 facilitates deployment of hardware independent function block model to the variety of compliant hardware.

This paper presents implementation of the Distributed Grid Intelligence (DGI) applications such as Intelligent Fault Management and Load Balancing using IEC61499 reference architecture. This enables system level design of distributed applications with a direct pathway to deployment to hardware. The use of IEC 61499 improves scalability, re-configurability and maintainability of automation software. Both applications were verified using co-simulation approach: control and power system simulated on PCs, and power system simulation on a PC networked with the number of distributed hardware running control algorithm. Both DGI applications were deployed to commercial programmable automation devices and embedded controllers. The use of IEC 61499 facilitates deployment of hardware independent function block model to the variety of compliant hardware. The paper also discusses distributed SCADA concept with IEC61499 implemented with the so-called Composite Automation Type (CAT) function blocks which combine functional and visual components. These blocks are used to implement human-machine interface of the FREEDM Smart Grid demonstrator reacting on plugging and unplugging of energy resources.

This paper introduces an approach to automatic verification of mechatronic systems designed as plug-and-play of Intelligent Mechatronic Components (IMC). The control logic of the system is composed from autonomous controllers of the IMCs and is automatically verified using model-checking. Net Condition Event Systems formalism (a modular extension of Petri net) is used to model the decentralized control logic and discrete-state dynamics of the plant. A re-configurable pick and place robot is used as an illustrative example. At first a three cylinder pick and place robot is used to design our new master-slave architecture for controller design and then the NCES models are re-used without much modification in a new 6 cylinder pick and place robot. The control model is then subjected to model checking using the ViVe/SESA model checker. A multi closed loop model of Plant and Controller is used and controller is extensively verified for safety, liveliness and functional properties of the robot. Computational Tree Logic (CTL) is used to specify these properties.

This paper proposes a step-by-step approach for developing modular and reusable logic controllers of mechatronic systems. Following that, it presents the results of employing three distributed control methods, including master-slave, peer-to-peer and independent controllers on a pick-and-place robot as a simple showcase of implementing a distributed control system on industrial applications, using the emerged IEC 61499 standard. Moreover, it addresses possibilities and challenges of using each approach.

A Self-Biased Charge-Transfer Sense Amplifier (SB-CTSA) is proposed for applications in high performance static memory. The new design incorporates an internal biasing mechanism along with a static output latch that can store the result from a read cycle indefinitely at no additional cost in power. It exhibits 23% faster sensing delay and a 37% reduction in read energy when compared to a recently proposed CTSA structure. In addition, the SB-CTSA design exhibits low sensitivity to both input capacitance and input capacitance mismatch.

An efficient voxel representation scheme coupled with algorithms for voxelisation, display and thickness analysis of complex free form shapes is presented. The binary voxel model is stored as a stack of layers represented as bit-arrays. Polygonal solid models are converted into voxel format with a maximum resolution of 1000 (one billion voxels) in less than 2 minutes. Near real-time visualization of the voxel model is achieved by direct point rendering using a look-up table based on a finite set of neighbour voxel configurations. Thickness analysis is performed in terms of cross-sectional visualisation, progressive skin removal and radiography with minimum, maximum and total thickness along an orthographic direction. Testing of the algorithms for intricate shapes like Ganesha idol, pelvis bone and automobile cylinder gave satisfactory results. The voxel framework can be coupled to traditional CAD/CAM systems, providing additional capabilities to product engineers.