Jeffrey Yan

Distributed Software Architecture Enabling Peer-to-Peer Communicating Controllers

This paper presents a novel model-driven software architecture for systems with high degree of redundancy and modularity of the equipment. The architecture is based on totally decentralized control. It combines adaptability and robustness of multi-agent control architectures with portability and interoperability benefits of IEC 61499 function block architecture. The architecture has been successfully proven feasible on a number of field trials, including modeling and implementation of a medium-scale airport baggage handling control. Deployment was done on distributed networks consisting of configurations ranging from a few to dozens of communicating control nodes. The work confirmed the ability to deliver similar functional characteristics as centralized systems but in a distributed implementation. Performance testing and development verified sufficient performance and software life-cycle benefits.

Distributed execution and cyber-physical design of Baggage Handling automation with IEC 61499

This paper proves feasibility of a fully distributed automation design of Baggage Handling Systems automation. The proposed design methodology leverages IEC 61499 Function Blocks as a supporting architecture. Each physical element of the BHS, such as a conveyor is represented by a Function Block that encapsulates functionality into a single re-usable module. The proposed solution demonstrates such benefits as flexibility, fault resilience and design re-use. A graph based representation of the system layout was used for rendering of the visualisation. The solution was prototyped using ISaGRAF — the first commercial implementation of IEC 61499 and tested on a network of 50 networked control nodes, each representing an embedded controller of a single conveyor or of a group of conveyors. The Ethernet communications framework was tested to confirm the appropriate levels of network utilisation and potential sources of delay were identified. This design approach can be regarded as cyber-physical since it naturally combines simulation models into the design life-cycle, providing ready to use simulation within the design framework.

Distributed IEC 61499 material handling control based on time synchronization with IEEE 1588

This paper proposes a method of time-driven control with high-precision synchronous clocks in distributed control systems built following the IEC 61499 standard. It investigates the impact of applying time-driven control on performance of material handling systems. A time-driven control system for a multi-diverter conveyor line has been developed using IEC 61499 Function Blocks architecture with support of the IEEE 1588 Precision Time Protocol. Analytic performance model has been developed and comparisons between the time-driven and two other possible control designs have been conducted and elaborated in terms of costs, logic design, and system throughput.

On composition of mechatronic components enabled by interoperability and portability provisions of IEC 61499: A case study

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.

Extension of reconfigurability provisions in IEC 61499

This paper presents an investigation into the implementation of reconfigurable industrial applications using the IEC 61499 standard. An architecture and design methodology is proposed to allow for the addition of reconfigurable elements to existing IEC 61499 applications. The commercially available NxtForte IEC 61499 platform was chosen for experiments. The notion of state resumption is discussed along with a corresponding application level implementation. Deficiencies of the standard for promoting reconfiguration are outlined and some extensions are then proposed to streamline the development of reconfigurable applications.

Towards implementation of Plug-and-Play and distributed HMI for the FREEDM system with IEC 61499

This paper presents an implementation of Plug-and-Play for the FREEDM system with IEC61499 function blocks. The FREEDM system is the envisioned next generation power distribution infrastructure which integrates DRER/ER with the legacy grid and is enabled by novel power electronics and distributed control. Plug-and-Play device integration is one of the key features of the FREEDM system that allows distributed renewable energy resources and distributed energy storage devices to be added or removed from the FREEDM distributed intelligent devices seamlessly. IEC61499 is an open standard for designing distributed control systems, which is investigated in the FREEDM project as an underlying system-level software architecture. Plug-and-Play is achieved by dynamic reconfiguration in IEC61499 to create the necessary function blocks during runtime for enabling Plug-and-Play between the DRER and the DGI devices. The developed Plug-and-Play technology is incorporated into the FREEDM infrastructure implemented in IEC61499 function blocks.

Cyber-physical components for heterogeneous modelling, validation and implementation of smart grid intelligence

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.

Adaptable software components: Towards digital ecosystems and software evolution in the industrial automation domain

This paper proposes new type of software components for distributed automation systems that are capable of adapting to the computational load conditions by migrating to other devices. The migration is seen as a basic mechanism of bio-inspired heuristic search for more optimal overall load across distributed network of devices. The adaptable components can form digital ecologies self-configuring themselves after changes in the environment. The proposed architecture is prototyped using extended IEC 61499 distributed reference architecture. A simple use case of a baggage handling system is used for illustration.

Knowledge-based routing in mechanical transportation systems

This paper presents the ways of constructing routing algorithms in mechanical transport systems based on knowledge. It is assumed that the experts observing system behavior applies his experience by designating subsystems with a specific behavior. To create routing tables, a model of fuzzy temporal hypergraph was used. We consider fixed and dynamic routing, given modifications of Dijkstras algorithm for the case of fuzzy temporal hypergraphs.

Time-complemented event-driven reconfigurable systems

The complexity of modern industrial automation systems means that designing with change in mind is a necessity. Event-driven and time-driven programming paradigms each have their own benefits for the development of distributed systems control. However, flexibility and reconfiguration will always be required as new technologies are introduced and increased distribution results in greater chances for point failures. Dynamic runtime based reconfiguration is desired to reduce any experienced downtime. Implementation of reconfiguration is problematic, particularly as the system grows in size. System behavior arises from complex interactions between distributed modules, making their reconfiguration inherently difficult. This paper proposes the unification of time-driven and event-driven control paradigms for the purpose of unification. A formal model discussing the suitability of this architecture for reconfiguration purposes is introduced. Each reconfiguration mechanism for the architecture and design patterns is then implemented in the IEC 61499 function block standard.