Immersive Display Interface Specification Standards in Virtual Manufacturing:A Prototype

In this paper we briefly describe our effort in developing standards for immersive display interfaces in virtual manufacturing.This work is being conducted in collaboration with the National Institute of Standards and Technology(NIST).First we review the concept of virtual manufacturing,discuss its scope and lay the contextual foundation for describing our application.Next we describe a prototype implementation of immersive display interfaces in virtual manufacturing.This prototype is based on processing the output of a factory simulation model.Finally we describe the standards emerging from this prototype.

A SYSTEMATIC ARCHITECTURE AND MODELING OF VIRTUAL MANUFACTURING AND MEASURING CELL

The concept of virtual manufacturing and measuring cell (VMMC) is proposed, the systematic architecture of the VMMC is established and two key problems: the error fusion in machining and the reconstructable modeling of workpiece during virtual manufacturing and measuring, are discussed. An actual VMMC is presented as an example and its modularized frame is introduced.

Integration of Manufacturing Services into Virtual Environments over the Internet

Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.

Simulation Based Energy-resource Efficient Manufacturing Integrated with In-process Virtual Management

As energy efficiency is one of the key essentials towards sustainability, the development of an energy-resource efficient manufacturing system is among the great challenges facing the current industry. Meanwhile, the availability of advanced technological innovation has created more complex manufacturing systems that involve a large variety of processes and machines serving different functions. To extend the limited knowledge on energy-efficient scheduling, the research presented in this paper attempts to model the production schedule at an operation process by considering the balance of energy consumption reduction in production, production work flow （productivity） and quality. An innovative systematic approach to manufacturing energy-resource efficiency is proposed with the virtual simulation as a predictive modelling enabler, which provides real-time manufacturing monitoring, virtual displays and decision-makings and consequentially an analytical and multidimensional correlation analysis on interdependent relationships among energy consumption, work flow and quality errors. The regression analysis results demonstrate positive relationships between the work flow and quality errors and the work flow and energy consumption. When production scheduling is controlled through optimization of work flow, quality errors and overall energy consumption, the energy-resource efficiency can be achieved in the production. Together, this proposed multidimensional modelling and analysis approach provides optimal conditions for the production scheduling at the manufacturing system by taking account of production quality, energy consumption and resource efficiency, which can lead to the key competitive advantages and sustainability of the system operations in the industry.

Multilevel manufacturing system of virtual enterprise based on manufacturing grid and strategies for member enterprise selection and task assignment

In order to improve efficiency of virtual enterprise, a manufacturing grid and multilevel manufacturing system of virtual enterprise is built up. When selecting member enterprises and task assignment based on the manufacturing grid, key activities are assigned to the suitable critical member enterprises by task decomposition, enterprise node searching and characteristic matching of manufacturing resources according to the characteristic matching strategy. By task merger, some ordinary activities are merged with corresponding key activities and assigned to corresponding critical member enterprises. However, the other ordinary activities are assigned to the related ordinary member enterprises with enterprise node searching and characteristic matching of manufacturing resources. Finally, an example of developing the artificial hip joint in the virtual enterprise is used to demonstrate that efficiency of the virtual enterprise is improved by using the manufacturing grid and the proposed strategies for member enterprise selection and task assignment.

Applications and research trends of digital human models in the manufacturing industry

Virtual reality(VR)has been widely used in various manufacturing industries,and VR-based virtual manufacturing has received significant attention in the current intelligent manufacturing era.Digital human models(DHMs)are essential for virtual manufacturing applications.Additionally,researching new applications of DHMs has developed into an important academic research field.This paper aims to identify the applications and research trends of DHMs in the manufacturing industry and to provide a reference for the continued development of virtual manufacturing and DHMs.We selected a total of 49 related articles from a large number of articles published between 2014 and 2019.The applications of DHMs in the manufacturing industry are analyzed from different perspectives and various relevant technical limitations are discussed.The results indicate that the applications of DHMs differ significantly between different types of fields.The automotive industry is the main application field for DHMs,and assembly/maintenance simulations and evaluations are the main application types.Additionally,there are still some limitations in the establishment of virtual environments,motion control,and DHM evaluation that should be addressed.Finally,research trends in the application of DHMs are illustrated and discussed,including the planning and assessment of human-robot collaboration systems,the combination of DHMs and augmented reality,and improved motion planning for DHMs.In summary,the application of DHMs can improve the realism and effectiveness of virtual manufacturing,and DHMs will be more widely and deeply studied and applied in various manufacturing industries in the near future.

Numerical and experimental evaluation for density-related thermal insulation capability of entangled porous metallic wire material

Entangled porous metallic wire material(EPMWM)has the potential as a thermal insulation material in defence and engineering.In order to optimize its thermophysical properties at the design stage,it is of great significance to reveal the thermal response mechanism of EPMWM based on its complex structural effects.In the present work,virtual manufacturing technology(VMT)was developed to restore the physics-based 3D model of EPMWM.On this basis,the transient thermal analysis is carried out to explore the contact-relevant thermal behavior of EPMWM,and then the spiral unit containing unique structural information are further extracted and counted.In particular,the thermal resistance network is numerically constructed based on the spiral unit through the thermoelectric analogy method to accurately predict the effective thermal conductivity(ETC)of EPMWM.Finally,the thermal diffusivity and specific heat of the samples were obtained by the laser thermal analyzer to calculate the ETC and thermal insulation factor of interest.The results show that the ETC of EPMWM increases with increasing temperature or reducing density under the experimental conditions.The numerical prediction is consistent with the experimental result and the average error is less than 4%.

Research of Web-based 3D collaborative CAPP system

This paper present an architecture of Web-based collaborative 3D CAPP （Computer Aided Process Planning） system. It is a three tired system basis of the VRML and ActiveX technology. This Web-based system implements collaborative functions such as fixture design, process planning, G-code simulation, etc. The manufacturing resource management also discussed, which composed of equipments information management, fixtures information management, cutting tools information management and process pa- rameters information management. In the end, the procedure of collaborative process planning based on this Web-based system is in- troduced. This 3D CAPP system can be used for geographically distributed engineers to make optimized process planning of the part or assembly.

GLOBAL MANUFACTURING VIRTUAL NETWORK (GMVN): A REVISITING OF THE CONCEPT AFTER THREE YEARS FIELDWORK

The idea of the global manufacturing virtual network (GMVN) was introduced in 2000 in order to highlight an emerging as well as an alternative manufacturing system which will have strong impacts on industry and implications to management theory. During the last three years, more than thirty companies - based in the electronics, bio-pharmaceuticals, garment, and home electronics appliance industries - have been studied in the UK and China. The research project addresses the emergence of the collaborative manufacturing phenomenon at three levels - sector, system and enabling technology. This paper summarises preliminary research findings from fieldwork conducted over the last three years. It seeks to clarify the characteristics and functionality of GMVN through the case studies and to contrast it to other types of business model, such as the multinational corporations (MNC) and international strategic alliances (ISAs). It also raises some new research questions and themes for further research into GMVN.

Revisiting digital twins: Origins, fundamentals, and practices

The digital twins(DT)has quickly become a hot topic since it was proposed.It appears in all kinds of commercial propaganda and is widely quoted by academic circles.However,the term DT has misstatements and is misused in business and academics.This study revisits DT and defines it to be a more advanced system/product/service modeling and simulation environment that combines most modern information communication technologies(ICTs)and engineering mechanism digitization and characterized by system/product/service life cycle management,physically geometric visualization,real-time sensing and measurement of system operating conditions,predictability of system performance/safety/lifespan,and complete engineering mechanisms-based simulations.The idea of DT originates from modeling and simulation practices of engineering informatization,including virtual manufacturing(VM),model predictive control,and building information modeling(BIM).On the basis of the two-element VM model,we propose a three-element model to represent DT.DT does not have its unique technical characteristics.The existing practices of DT are extensions of the engineering informatization embracing modern ICTs.These insights clarify the origin of DT and its technical essentials.

Collection and Management of Shop-floor Controller Data

This paper describes shop floor data collection and management. An architecture is presented for a shop floor data collection and management system based on the analysis of the features of these data. Two critical aspects of the system are discussed in detail: the various communication protocols between computers and machines, and the real time demands of the shop floor controller.