Cheng Pang

Closed-Loop Modeling in Future Automation System Engineering and Validation

This paper presents a new framework for design and validation of industrial automation systems based on systematic application of formal methods. The engineering methodology proposed in this paper is based on the component design of automated manufacturing systems from intelligent mechatronic components. Foundations of such componentspsila information infrastructure are the new IEC 61499 architecture and the automation object concept. It is illustrated in this paper how these architectures, in conjunction with other advanced technologies, such as Unified Modeling Language, Simulink, and net condition/event systems, form a framework that enables pick-and-place design, simulation, formal verification, and deployment with the support of a suite of software tools. The key feature of the framework is the inherent support of formal validation techniques achieved on account of automated transformation among different system models. The paper appeals to developers of automation systems and automation software tools via showing the pathway to improve the system development practices by combining several design and validation methodologies and technologies.

Model-Driven Development of Control Software for Distributed Automation: A Survey and an Approach

This paper presents a survey on model-driven design and validation approaches for distributed automation and control systems with essentially decentralized logic. Driven by the goals of flexibility and performance improvement, researchers have explored several approaches to distributed systems design, including multiagent systems, middleware, and distributed component architectures. This also results in several international standards and reference architectures, such as IEC 61499, OpenRTM, IEC 61804, etc. Verification and validation of distributed systems is another grand challenge. This survey presents methods of using traditional and novel modeling and simulation tools in the context of distributed systems. In particular, this paper then focuses on the developments related to IEC 61499 standard, which displays a range of research directions that aim to fill the gaps in the distributed systems modeling, implementation, and validation.

Virtual smart metering in automation and simulation of energy-efficient lighting system

Building Automation and Control System (BACS) is a promising contributor for conserving building energy consumption. This paper proposes a virtual smart metering approach as an integral part of BACS for the demand control of building services. It can assist consumers to monitor the energy consumption and take measures to rationalize their energy efficiency at a finer granularity. This virtual smart metering enables the simulation-based energy efficiency evaluation of different automation and control strategies. It also establishes the load controlling infrastructure for further Demand Side Management at building side. A prototype lighting control system using virtual smart metering has been developed, where different control strategies can be simulated. It has been demonstrated that how intelligent lighting control taking daylight luminance and occupant presence into account can achieve better energy efficiency.

Automatic model generation of IEC 61499 function block using net condition/event systems

The IEC 61499 standard establishes a framework specifically designed for the implementation of decentralized reconfigurable industrial automation systems. However, the process of distributed systempsilas validation and verification is difficult and error-prone. This paper discusses the needs of model generators which are capable of automatically translating IEC 61499 function blocks into formal models following specific execution semantics. In particular, this paper introduces the prototype Net Condition/Event Systems model generator and aims to summarize the generic techniques of model translation.

Neutralizing Semantic Ambiguities of Function Block Architecture by Modeling with ASM

The Function Blocks Architecture of the IEC 61499 standard is an executable component model for distributed embedded control systems combining block-diagrams and state machines. The standard aims at the portability of control applications that is however hampered by ambiguities in its execution semantics descriptions. In recent years several execution models have been implemented in different software tools that generate mutually incompatible code.

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.

IEC 61499 function block implementation of Intelligent Mechatronic Component

This paper presents a new approach of implementing Intelligent Mechatronic Component (IMC) using the IEC 61499 Function Block standard. In particular, this paper tries to address two issues during the engineering process of IMCs: a systematic approach of developing and organizing IMC elements and a seamless and scalable way supporting IMC composition and reconfiguration. A case study implementation example is presented to illustrate how the results from this work can be applied and integrated in Function Block development tools.

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.

Time-stamped event based execution semantics for industrial cyber-physical systems

Cyber-physical systems show their impacts in many areas including industrial automation. Design and analysis of cyber-physical automation systems requires an integral model that takes into account tight coordination of control, communication and physical plants dynamics, thus creating a new research domain, namely industrial cyber-physical systems. This paper proposes a new execution semantics for the IEC 61499 standard that is based on the concepts of discrete-event systems augmented with timestamping of events to guarantee real-time constraints for industrial cyber-physical systems. The proposed execution semantics is implemented in an IEC 61499 execution environment and a case study on building automation systems is used to verify the results.

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 controllers logic and the resulting controlled object ...