STEP COMPLIANT APPROACH FOR TURN-MILL OPERATIONS

Current machine tools have incurred challenges on limitation such as part programming complexity of G and M code, weak integration of digital machine tools and coverage of universal data modeling for product and manufacturing resources. In response to this manufacturing system requirement, Standard for Exchange of Product data (STEP) and its implementation on developing an interface for the next generation of machine tool controllers (STEP-NC) has become a concern of research interest and performed on basic manufacturing technology limited to a unit domain such as turning, milling or Wire EDM. Therefore; extending this STEP implementation on multipurpose machine tools such as turn-mill machines is mandatory since the machines are the main component in these industries. The research work offers a STEP-NC compliant interface supporting turn-mill machining environment identified as SCSTMO

STEP-NC-compliant implementation to support mixed-control technologies applied to stone-processing machines based on industrial automation standards

STEP-NC (Standard for the Exchange of Product Model Data–Numerical Control) for metal milling and turning is not implemented by industrial computer numerical controllers. Solutions reported are prototypes based on post-processing in G-code. Moreover, minority machining processes, such as stone cutting, have not yet been contemplated in the STEP-NC standard. This article takes that sector as a use case. An extended STEP-NC model for circular saw stone-cutting operations is proposed, and a prototype automation implementation is developed to work with this extended model. This article shows how modern technological resources for coordinated axes control provided by many industrial controllers for the automation of general-purpose machines can speed up the processes of implementing STEP-NC numerical controllers. This article proposes a mixed and flexible approach for STEP-NC-based machine automation, where different strategies can coexist when it comes to executing STEP-NC machining files, so controllers do not need to implement the standard in an exhaustive way for all the possible features, but only at selected ones when convenient. This is demonstrated in a prototype implementation which is able to process STEP-NC product files with mixed-feature types: standard milling and non-standard sawblade features for stone processing

A Design for a Novel Open, Intelligent and Integrated CNC System Based on ISO 10303-238 and PMAC

The combination of the high-level data model called ISO 10303-238 with the open programmable multi-axis controller (PMAC) presents a vision for the open, intelligent and integrated computer numerical control (CNC) systems whose demands have been growing with the rapid development of modern manufacturing. Evolved from design philosophy, this paper proposes a novel open, intelligent and integrated CNC system based on ISO 10303-238 and PMAC. In the system, ISO 10303-238 is chosen as the numerical control (NC) data in order to make the CNC system interoperable. And the open master-slave hardware structure on the basis of industrial process computer (IPC) + PMAC with double central processing units (CPUs) is designed in order to make the CNC system flexible. Also, the open and modular software structure is designed in order to make the CNC system intelligent. In addition, the development of the prototype system is given. At the end, it has been verified by case study that the proposed CNC system is feasible and effective

A Survey of Automated Process Planning Approaches in Machining

Global industrial trend is shifting towards next industrial revolution Industry 4.0. It is becoming increasingly important for modern manufacturing industries to develop a Computer Integrated Manufacturing (CIM) system by integrating the various operational and information processing functions in design and manufacturing. In spite of being active in research for almost four decades, it is clear that new functionalities are needed to integrate and realize a completely optimal process planning which can be fully compliant towards Smart Factory. In order to develop a CIM system, Computer Aided Process Planning (CAPP) plays a key role and therefore it has been the focus of many researchers. In order to gain insight into the current state-of-the-art of CAPP methodologies, 96 research papers have been reviewed. Subsequent sections discuss the different CAPP approaches adopted by researchers to automate different process planning tasks. This paper aims at addressing the key approaches involved and future directions towards Smart Manufacturing

STEP COMPLIANT APPROACH FOR TURN-MILL OPERATIONS

Current machine tools have incurred challenges on limitation such as part programming complexity of G and M code, weak integration of digital machine tools and coverage of universal data modeling for product and manufacturing resources. In response to this manufacturing system requirement, Standard for Exchange of Product data (STEP) and its implementation on developing an interface for the next generation of machine tool controllers (STEP-NC) has become a concern of research interest and performed on basic manufacturing technology limited to a unit domain such as turning, milling or Wire EDM. Therefore; extending this STEP implementation on multipurpose machine tools such as turn-mill machines is mandatory since the machines are the main component in these industries. The research work offers a STEP-NC compliant interface supporting turn-mill machining environment identified as SCSTMO

An approach to accessing product data across system and software revisions

Long-term users of engineering product data are hampered by the ephemeral nature of CAD file formats and the applications that work with them. STEP, the Standard for the Exchange of Product Model Data (ISO 10303), promises to help with meeting this challenge, but is not without problems of its own. We present a complementary solution based on the use of lightweight file formats to preserve specific aspects of the product data, in conjunction with a registry of relevant representation information as defined by the Open Archival Information System Reference Model (ISO 14721). This registry is used to identify suitable destination file formats for different purposes, and provides a resource to aid in the recovery of information from these formats in the future.

From computer-aided to intelligent machining: Recent advances in computer numerical control machining research

The aim of this paper is to provide an introduction and overview of recent advances in the key technologies and the supporting computerized systems, and to indicate the trend of research and development in the area of computational numerical control machining. Three main themes of recent research in CNC machining are simulation, optimization and automation, which form the key aspects of intelligent manufacturing in the digital and knowledge based manufacturing era. As the information and knowledge carrier, feature is the efficacious way to achieve intelligent manufacturing. From the regular shaped feature to freeform surface feature, the feature technology has been used in manufacturing of complex parts, such as aircraft structural parts. The authors’ latest research in intelligent machining is presented through a new concept of multi-perspective dynamic feature (MpDF), for future discussion and communication with readers of this special issue. The MpDF concept has been implemented and tested in real examples from the aerospace industry, and has the potential to make promising impact on the future research in the new paradigm of intelligent machining. The authors of this paper are the guest editors of this special issue on computational numerical control machining. The guest editors have extensive and complementary experiences in both academia and industry, gained in China, USA and UK

A multi-perspective dynamic feature concept in adaptive NC machining of complex freeform surfaces

This paper presents a new concept of feature for freeform surface machining that defines the changes in feature status during real manufacturing situations which have not been sufficiently addressed by current international standards and previous research in feature technology. These changes are multi-perspective, including (i) changes in depth-of-cut: the geometry of a feature in the depth-of-cut direction changes during different machining operations such as roughing, semi-finishing and finishing; (ii) changes across the surface: a surface may be divided into different machining regions (effectively sub-features) for the selection of appropriate manufacturing methods for each region such as different cutting tools, parameters, set-ups or machine tools; and (iii) changes in resources or manufacturing capabilities may require the re-planning of depth-of-cuts, division of machining regions and manufacturing operations (machines, tools, set-ups and parameters). Adding the above dynamic information to the part information models in current CAD systems (which only represent the final state of parts) would significantly improve the accuracy, efficiency and timeliness of manufacturing planning and optimisation, especially for the integrated NC machining planning for complex freeform surfaces. A case study in an aircraft manufacturing company will be included in this paper

Conceptual framework for closed-loop inspection based on the coordinate measurement technology adherent to STEP-NC

Tese (doutorado) — Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2021.As demandas por qualidade e produtividade na fabricação de peças com especificações de projeto com- plexas representam novos desafios para os processos de fabricação e sistemas de inspeção de qualidade. Os desafios são coletar, processar, transmitir e armazenar dados do processo de fabricação e inspeção e refinar cada processo relacionado ao ciclo de vida do produto. Conceitos como integração e interoperabili- dade, relevantes no contexto digital, apresentam barreiras que impedem sua plena implementação no atual cenário de manufatura. A implementação de uma malha fechada de manufatura permite que os resulta- dos da inspeção sejam realimentados na cadeia digital e usados para tomar decisões nas fases de projeto, planejamento e fabricação que reduzem as incertezas na fabricação. A inspeção dimensional e geométrica permite a geração de dados contendo vestígios de fabricação. Esses dados processados corretamente podem fornecer conhecimento sobre as causas do desvio da peça fabricada e as condições de fabricação que podem ser melhoradas. Este trabalho de tese se enquadra nesta perspectiva e apresenta uma solução de integração de dados gerados nas diferentes fases do ciclo de vida de um produto. A integração de dados ocorre em uma arquitetura de manufatura em malha fechada por meio de uma linguagem neutra, extensível e sintaticamente homogênea que permite vincular informações de projeto, manufatura, resultados de medição e suportar o fluxo por meio de sistemas CAx (tecnologias assistidas por computador). Como resultado da pesquisa, a arquitetura de integração interoperável baseada no padrão ISO10303 e seus protocolos de aplicação é apresentada, cobrindo especificações de projeto, requisitos de fabricação e troca de informações de inspeção dimensional e geométrica. Uma implementação computacional é desenvolvida usando o ambiente Java para manipular esquemas EXPRESS, gerar bibliotecas com entidades, funções, métodos e desenvolver uma aplicação que permite ler, escrever e modificar arquivos neutros de troca STEP. A metodologia seguida por meio de uma estrutura conceitual prática é exposta para gerar novas aplicações baseadas na norma ISO 10303. Três estudos de caso são apresentados para verificar a integração e interoperabilidade dentro da arquitetura de manufatura em malha fechada. Os resultados revelam novas linhas de pesquisa que são propostas para trabalhos futuros.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).The demands for quality and productivity in manufacturing parts with complex design specifications pose new challenges for manufacturing processes and quality inspection systems. The challenges are collecting, processing, transmitting, and storing data from the manufacturing and inspection process and refining each process related to the product life cycle. Concepts such as integration and interoperability, relevant within the digital context, show barriers that prevent their full implementation within the current manufacturing scenario. Implementing a closed manufacturing loop allows inspection results to be fed back into the digital chain and used to make decisions in the design, planning, and manufacturing phases that reduce uncertainties in manufacturing. Dimensional and geometric inspection allows the generation of data containing traces of manufactur- ing. These correctly processed data can provide knowledge about causes of deviation of the manufactured part and manufacturing conditions that can be improved. This thesis work is framed within this perspective and presents a solution for integrating data generated in the different phases of the life cycle of a prod- uct. Data integration occurs within a closed-loop manufacturing architecture through a neutral, extensible, syntactically homogeneous language that allows both linking design information, manufacturing, measure- ment results, and supporting the flow through Computer-Aided Technologies (CAx) systems. As a result of the research, interoperable integration architecture based on the ISO10303 standard and its application protocols is presented, covering design specifications, manufacturing requirements, and dimensional and geometric inspection information exchange. A computational implementation is developed using the Java environment to manipulate EXPRESS schemas, generate libraries with entities, functions, methods and develop an application that allows read- ing, writing, and modifying neutral STandard for the Exchange of Product model data (STEP) exchange files. The methodology followed through a practical conceptual framework is exposed to generate new applications based on the International Standards Organization (ISO) 10303 standard. Three case studies are presented to verify integration and interoperability within the closed-loop manufacturing architecture. The results reveal new lines of research that are proposed for future work