Dimitris Mavrikios

Digital manufacturing: History, perspectives, and outlook

Abstract Digital manufacturing has been considered, over the last decade, as a highly promising set of technologies for reducing product development times and cost as well as for addressing the need for customization, increased product quality, and faster response to the market. This paper describes the evolution of information technology systems in manufacturing, outlining their characteristics and the challenges to be addressed in the future. Together with the digital manufacturing and factory concepts, the technologies considered in this paper include computer-aided design, engineering, process planning and manufacturing, product data and life-cycle management, simulation and virtual reality, automation, process control, shopfloor scheduling, decision support, decision making, manufacturing resource planning, enterprise resource planning, logistics, supply chain management, and e-commerce systems. These technologies are discussed in the context of the digital factory and manufacturing concepts.

A virtual reality-based experimentation environment for the verification of human-related factors in assembly processes

Abstract This paper investigates the use of virtual reality (VR)-based methods for the verification of performance factors related to manual assembly processes. An immersive and interactive virtual environment has been created to provide functionality for realistic process experimentation. Ergonomic models and functions have been embedded into the VR environment to support verification and constrain experimentation to ergonomically acceptable conditions. A specific assembly test case is presented, for which a semi-empirical time model is developed employing statistical design experimentation in the virtual environment. The virtual experimentation results enable the quantification and prediction of the influence of a number of process parameters and their combination at the process cycle time.

On industrial learning and training for the factories of the future: a conceptual, cognitive and technology framework

The manufacturing education addresses significant challenges in view of paving the way for the human capital of the Factories of the Future. This paper introduces a specification framework for the delivery of industrial learning and training, addressing the needs for the “knowledge” workers of the factories of the future. A review of the relevant background, including the activities associated with the industrial learning and its basic methods as well as some emerging paradigms, is first provided. A Teaching Factory based paradigm is then suggested as the conceptual foundation of this framework. A cognitive framework, addressing the major building blocks of the industrial learning process, namely the attitude the knowledge the skills and the competences is being defined. An appropriate technology framework, dealing with the needs of engineers and blue-collar workers, for practising the manufacturing knowledge content within digital environments, is suggested at this point. Finally, the approach of the future implementation of the specific framework is being discussed.

Development of a web-based collaboration platform for manufacturing product and process design evaluation using virtual reality techniques

This paper describes the development of a web-based platform for collaborative process and product design evaluation. The distributed collaborative design evaluation (DiCoDEv) platform provides real-time collaboration of multiple users at different sites on the same project. The innovation concept of this platform lies in the use of virtual reality (VR) technology for the development of the working display environment that provides also navigation, immersion and interaction capabilities for all collaborative users in real time. The scope of this work is to provide an efficient robust collaboration tool for the real-time validation of a manufacturing product or process, from the early stages of the conceptual design until the latest stages of the production chain. In order to demonstrate the benefits of the virtual collaboration that DiCoDEv platform can provide for manufacturing, a pilot case with a VR environment has been developed based on the requirements of a ‘real life’ manufacturing company.

A prototype virtual reality-based demonstrator for immersive and interactive simulation of welding processes

This paper investigates the use of virtual reality (VR)-based methods to support human-integrated simulation for manual welding processes. Within this concept, a prototype demonstrator has been developed, called ‘the virtual welding environment’, which provides functionality for an immersive and interactive process execution within a virtual environment. The simulation features of this environment enable the user to set up, execute and validate the results of a welding process. This environment demonstrates a promising potential for supporting process design and training procedures related to manual welding.

The role of simulation in digital manufacturing: applications and outlook

Digital manufacturing technologies have been considered an essential part of the continuous effort towards the reduction in a product’s development time and cost, as well as towards the expansion in customisation options. The simulation-based technologies constitute a focal point of digital manufacturing solutions, since they allow for the experimentation and validation of different product, process and manufacturing system configurations. This article investigates simulation-based applications in a series of different technological and manufacturing domains. First, this article discusses the current industrial practice, focusing on the use of information technology. Next, a series of simulation-based solutions are explored in the domains of product and production process design, as well as in the area of enterprise resource planning. The current technologies and research trends are discussed in the context of the new landscape of computing hardware technologies and the emerging computing services, including the initiatives comprising both the Internet cloud and the Internet of things.

A novel virtual experimentation approach to planning and training for manufacturing processes--the virtual machine shop

This paper discusses the use of a virtual experimentation environment as a planning and training tool for machining processes. This approach involves the virtual performance of machining processes within a Virtual Machine Shop environment. The features of this environment enable the user to set up a process, to operate a machine tool, to edit and execute an NC part program in an immersive and interactive way. Additional functions are provided in order to support process verification in terms of geometrical, technical and economic characteristics. A test case is presented in order to demonstrate the simulation functions of the Virtual Machine Shop and the capability of the system to deal with machining planning and training problems.

Ergonomic Evaluation Of Virtual Assembly Tasks

This paper investigates the use of Virtual Reality and Human Simulation technologies for the ergonomic evaluation of manual assembly tasks. Within this concept, a virtual environment has been developed for the realistic representation of assembly stations into which digital humans can be imported and used to evaluate assembly executions in terms of ergonomics aspects. The industrial need lies on the reduction of process time and on the ergonomic optimization of the assembly workstations. The use of this environment enables the identification of critical steps during an assembly execution, which provides stress to humans resulting in increased assembly times and over wearied operators. A real life assembly task of a commercial refrigerator has been simulated and presented in order to demonstrate environment capabilities.

A web-based platform for collaborative product design and evaluation

This paper presents a web-based integrated platform for supporting the collaborative product design activities. An overview of the overall Digital Factory framework, in which the Collaborative Prototype Designer (CPD) resides, has been given first. Next, the CPDs functional architecture is presented including the way it addresses the needs for collaboration during the product design process. The CPD is based on the integration of a spectrum of technologies, including Content Management, Computer-Aided Design (CAD), Virtual & Augmented Reality (VR/AR) and Decision Support, through a Web-based user friendly interface. The major contribution of the proposed approach is the CPDs flexible architecture, which takes into consideration the design needs of both mechanical and nonmechanical products and it is therefore, considered being applicable to a wide range of products. It integrates design activities, processes, methods and tools in a modular feature, easy to be used and be enhanced even further. The CPD mainly aims at SMEs that usually cannot afford an expensive commercial solution, for supporting of the collaborative product design.

A Hybrid Approach to the Verification and Analysis of Assembly and Maintenance Processes Using Virtual Reality and Digital Mannequin Technologies

This chapter discusses the concept and the first pilot implementation of a hybrid approach to the realistic representation of human performance in virtual manufacturing environments. The approach employs simulation principles of both virtual reality (VR) and digital mannequin (DM) technologies. The software tool developed, called VRSP, enables the immersive virtual performance of an industrial task, in an adequately realistic and user-friendly way, and the control of a mannequin within the virtual environment, based upon the spatially tracked user interactions of the immersed human. Design and implementation aspects of VRSP are described. An industrial test case is presented to demonstrate the capability of VRSP to deal with real process tasks. There follows a discussion, focused on the results and the future perspectives of this research work.