IMPLEMENTING DOMAIN PROCESS MODEL AS A NAVIGATOR FOR COOPERATIVE WORK DOMAIN

SFC (Sequential Function Chart) is a kind of graphic representations, which is included in IEC standards for sequential control systems. It is introduced as a specific form of PC's (Programmable Controller's) programs. For the simplicity of graphic representations and the clarity of relations of sequences, SFC is much superior to Ladder Diagram that has been so far, widely used in sequential control systems. Each element of SFC is meaningful just by the connections and SFC is strong in the representation of a flow of control sequence. However, SFC has a weak point that it is difficult to describe logic by conditions in detail like interlock relations and to represent interrupt processing. But production rules are obviously suitable for representing logic by conditions and also for interrupting process.In this paper, we propose a method to translate SFC into production rules, and to implement SFC by production rules using RTPS (Real Time Production System) in which PSL (Production System Language) is used to describe production rules. SFC has three description elements: step representing states in systems, transition representing transition conditions of systems, and link representing the connections between step and transition. We classify the flows of SFC to three types: single sequence, selective sequence and parallel sequence, and, show that each sequence can be described by pairs of transition-step. Conceming a pair of transition-step, a rule for translating the pair of transition-step into production rules is presented. These production rules will be represented by PSL. Finally, we show an example that is implemented by an RTPS.

According to the requirements of IEC61131-3 standard, the system of Programmable Logic Controller (PLC) using Sequential Function Chart (SFC) as the main programming language is build. Aiming at the requirements of the SFC programming system, the framework of SFC is established, on this basis, a suit of data structure based on Object-Oriented thinking is designed. It describes the data structure of SFC mainly, and in this way, the functions of SFC, including edit, modify and compile, etc, are realized.The syntax check and logic check of SFC are achieved by traveling recursively and iterating the layers of the nested data structure of SFC. After making SFC into intermediate code, eventually the intermediate code is translated into the corresponding object code.

One of the most difficult aspects of modeling complex dilemmas in decision-analytic terms is composing a diagram of relevance relations from a set of domain concepts. Decision models in many domains, however, exhibit certain prototypical patterns that can guide the modeling process. Concepts can be classified according to semantic types that have characteristic positions and typical roles in an influence-diagram model. The authors have developed a graph-grammar production system that uses such inherent interrelationships among terms to facilitate the modeling of medical decisions. The authors' system also can examine a set of graph-grammar rules to establish whether the grammar satisfies a number of properties that they have determined to be important in the derivation of influence-diagram models. The authors' findings suggest that syntactic patterns can lead to automated construction of decision models in domains other than medicine.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Proposed new troubleshooting methods for programmable controllers (PCs). Through studies of field applications in the tire industry the sequential function chart (SFC) is recognized as not only a powerful substitution for ladder logic diagram but also as useful in machine trouble diagnosis. Typical enhancements of SFC as self diagnostic function are; 1) to search the conditions which cause the machine to halt, 2) to collect logging table data for the historical program paths analysis, and 3) to specify the cause of the trouble by tracing back 1) and 2). This paper discusses the self diagnostic functions by SFC and its implementation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This paper considers a whitelisting system for programmable logic controllers (PLCs). In control systems, controllers are final fortresses to continues the operation of field devices (actuators/sensors), but they are fragile with respect to malware and zero-day attacks. One of the countermeasures applicable for controllers is a whitelisting system which registers normal operations of controller behavior in a “whitelist” to detect abnormal operations via a whitelist. The previous research of the current author proposed a PLC whitelisting system with a control via a ladder diagram (LD). LD representations have a wide applicability because LDs can be implemented for all PLCs and security functions without hardware/firmware updates. However, the current status requires that all instances are manually entered in the whitelist. In this talk, we show how the setting up of the can be automatized whitelist from the PLC behavior. This paper introduces an auto-generation approach for the whitelist using sequential function chart (SFC) instead of the LD. SFC and LD are compatible representations for the PLC. Using Petri Net modeling, this paper proposes how to generate the whitelist from the SFC and how to detect abnormal operations via the whitelist. We call the SFC-based approach the model-based whitelist, the Petri Net based approach the model-based detection. Further, this paper carries out an experimental validation of the algorithms using an OpenPLC based testbed system.

Fault Detection and Isolation on Hybrid Systems by SFC

Validation of a SFC Software Specification by Using Hybrid Automata

Semantic Modelling of Hybrid Controllers for Robotic Cells

The unified modeling language (UML) is widely used to analyze and design different software development artifacts in an object oriented development. Domain model is a significant artifact that models the problem domain and visually represents real world objects and relationships among them. It facilitates the comprehension process by identifying the vocabulary and key concepts of the business world. Category list technique identifies concepts and associations with the help of pre defined categories, which are important to business information systems. Whereas noun phrasing technique performs grammatical analysis of use case description to recognize concepts and associations. Both of these techniques are used for the construction of domain model, however, no empirical evidence exists that evaluates the quality of the resultant domain model constructed via these two basic techniques. A controlled experiment was performed to investigate the impact of category list and noun phrasing technique on quality of the domain model. The constructed domain model is evaluated for completeness, correctness and effort required for its design. The obtained results show that category list technique is better than noun phrasing technique for the identification of concepts as it avoids generating unnecessary elements i.e. extra concepts, associations and attributes in the domain model. The noun phrasing technique produces a comprehensive domain model and requires less effort as compared to category list. There is no statistically significant difference between both techniques in case of correctness.

Design Method on Optimal Flexible Manufacturing Systems

This article reports the results of research into software project management. the main contribution of this research is a software project management framework that consists of a static structure, shown in an entity-relationship diagram, and a description of each component of the framework. It also describes the procedure to design and validate the framework. This consists of integrating the solutions of a traditional model (information model) and a formal model (domain analysis). This software project management framework is a key element for rapid and effective project management process improvement of a software organization.

To facilitate efficient procedure synthesis, the extended finite automata are adopted in this work to model all components in a chemical process. The intended operation is divided into several stages and each characterized with a set of unique features, e.g., stable operation, condition adjustment, material charging and/or unloading, etc. The control specifications of every stage should then be stipulated accordingly and also described with automata. The observable event traces (OETs) embedded in this system can be produced by synchronizing all aforementioned automata. The candidate operating procedures are summarized with sequential function charts (SFCs) on the basis of these OETs. The commercial package ASPEN Plus Dynamic has been used to validate these SFCs in simulation studies.

Test sequence construction from SFC specification

PLC 제어 시스템은 SFC 언어를 사용하여 설계할 경우, SFC 언어를 사용하면 제어의 흐름을 이해하기 쉽고, 유지보수가 용이하며 프로그램의 기술성이 뛰어나다. SFC 언어는 단일 시퀀스, 선택 시퀀스, 병렬 시퀀스로 나누어지며, 선택 시퀀스로 프로그래밍 하면 단일 시퀀스로 프로그램할 때보다 메모리의 크기가 커져야 한다. 본 논문에서는 선택 시퀀스의 기능을 단일 시퀀스로 구현하여 메모리의 크기를 줄여서 메모리의 효율을 향상시키는 방법을 제시하고, 실례를 통해 타당성을 확인하였다.

Entity-Relationship (ER) diagrams are widely used in software engineering to model relational databases and serve as semantic representations easily understood by humans. They convey the meaning of data, their relationships, and key modeling concepts. Despite their usefulness, designing ER diagrams requires technical expertise. This work proposes a prototype leveraging natural language processing tools, particularly large language models (LLMs), to simplify and democratize their creation. Using simple prompts, the system generates structured outputs in standard formats that can later be used for ER diagram construction. As a result, a web application was developed, offering a user-friendly interface that reduces time and effort, aiming to make diagram creation more accessible.