George Chryssolouris

• PhD
• Principal Investigator at University of Patras

This paper presents a methodology to calculate the Remaining Useful Life (RUL) of machinery equipment by utilising physics-based simulation models and Digital Twin concept, in order to enable predictive maintenance for manufacturing resources using Prognostics and health management (PHM) techniques. The resources and the properties of them are firs...

In human-robot collaborative assembly, robots are often required to dynamically change their pre-planned tasks to collaborate with human operators in a shared workspace. However, the robots used today are controlled by pre-generated rigid codes that cannot support effective human-robot collaboration. In response to this need, multi-modal yet symbio...

A theoretical investigation into the potential energy savings by the optimization of robot motion acceleration profiles, has been presented. The investigation is restricted to motion profiles that do not alter the motion time, so that neither is new equipment required nor are production cycle times altered. Example cases show that simple principles...

Industrial production systems as well as manufactured products are constantly evolving due to new technologies and customer demands. Towards ensuring an optimized co-evolution of both, the concept of Teaching Factory uses advanced ICTs and high-grade industrial didactic equipment to operate as a non-geographically anchored learning “space”. In this...

The importance of leveraging manufacturing teaching and training, up to the standards of current and future needs, is quite evident. Recent studies have shown the urgency for future engineers and knowledge workers to adopt new teaching curricula in order to cope with the increasing industrial requirements. Teaching and Learning Factories aim at ali...

Dematerialisation refers to the decline, over time, of material usage in industrial products. The subject of this paper is to identify the relationship between the material and knowledge content of several products. The issue is whether the knowledge content, through time, will be affecting the products, in terms of dematerialisation. Specifically,...

Utilizing this Simulation and Design Strategy will have benefits in : • Design, by utilizing the more accurate predictions for the design of better parts • Manufacturing, contributing to the optimization of the Key Performance Indicators of the Automated Lay-up Process • Monitoring, due to the computational speed of the analytical equations instead...

The industrial sector is increasingly concerned with energy consumption, due to the environmental burden and increased cost. An action plan requires the study of energy efficiency in manufacturing processes, especially energy-intensive processes. The energy consumption, during the assembly, plays a significant role on the product’s final energy and...

Learning factories present a promising environment for education, training and research, especially in manufacturing related areas which are a main driver for wealth creation in any nation. While numerous learning factories have been built in industry and academia in the last decades, a comprehensive scientific overview of the topic is still missin...

This paper proposes a method for human–robot (HR) task planning, considering at the same time, the design of the workplace. A model for the representation of humans and robots as a team of active resources is proposed, while equipment such as working tables and fixtures are considered passive resources. The HR workload is structured in a three-leve...

The paper presents an Augmented Reality (AR) tool for supporting operators where humans and robots coexist in a shared industrial workplace. The system provides AR visualization of the assembly process, video and text based instructions and production status updates. The tool also enhances the operator's safety and acceptance of hybrid assembly env...

This paper investigates the effect of introducing multi-purpose mobile robot manipulators to an assembly system. These units are easily relocated in the shop floor and are able to perform a plethora of production processes. This approach increases the system's responsiveness either in the case of planned system reconfigurations or in the resources...

The use of digital simulation tools for the planning and verification of manufacturing processes has been identified as a key enabler technology. Through these tools, the need for physical prototypes is reduced, thus enabling the early assessment of decisions, regarding the efficiency of processes. The same stands for manual assembly planning. Howe...

Sustainability, in terms of energy consumption and the emissions impact on both natural environment and human health constitute a major concern in modern society. In the current study, the environmental footprint of the processes related to the manufacturing of cylinder heads for a diesel and a petrol automotive powertrain is investigated with the...

Remote Laser Welding (RLW) provides new possibilities for the highly productive and flexible joining of metal structures, especially in the automotive industry. In this study, the main advantages and limitations of the RLW technology are discussed against the major rival technology, namely the Resistance Spot Welding (RSW). Additionally, an evaluat...

Manufacturing systems utilize data communications in order to monitor and control signals to be communicated either between the process and the controller or within the Manufacturing Execution System (MES), in general. Such communications, mostly wireless, which are usually studied in the framework of Networked Control Systems (NCS), have certain e...

The Human Robot Collaborative (HRC) workplace design and the automatic task allocation can significantly decrease the time of a new set-up or a cell's reconfiguration. This paper proposes a method for an HRC workplace layout generation and the preliminary assignment of human and robot tasks. A decision making framework is proposed in order for the...

The generation of assembly process plans of complex products is a challenging task. An assembly processing planning system reducing the human intervention and the computational effort is discussed. The method utilizes the information stored into the CAD model of the assembly for the extraction of the part precedence information which is then comple...

The autonomous robot technology can be used for part supply in assembly lines since it provides efficient handling and transport. This paper proposes a decision making method for plan generation of part supply operations undertaken by Mobile Assistant Units (MAUs). Time and inventory levels are used as decision making criteria. The method was teste...

In modern assembly lines, humans and robots coexist and collaborate for the execution of complex tasks. The sequence and the assignment of tasks to suitable resources, constitute a technological challenge. For the collaboration of humans and robots, in a single assembly station, a common modelling language is required. This paper examines the way t...

An optimization strategy is described herein for the design and manufacturing of parts, combining composites and metals. The design stages of such parts, as well as the modelling procedures, required in each stage, are presented. More specifically, the modelling steps that are essential for the optimization of the production processes are described...

With non-conventional manufacturing processes, being increasingly integrated into manufacturing process chains, controllers and control strategies, remote nowadays, have to take into account a plethora of phenomena and criteria. The current study addresses the challenges, associated with the framework of the thermal oriented processes, having holis...

Robot programming software tools are expected to be more intuitive and user friendly. This paper proposes a method for simplifying industrial robot programming using visual sensors detecting the human motions. A vocabulary of body and hand gestures is defined, allowing the movement of robot in different directions. An external controller applicatio...

In a manufacturing shop-floor, context-aware intelligent service systems, along with mobile solutions can be used for the provision of information services to shop-floor personnel according to their situation. This paper presents an Industry 4.0 system that provides decision support for line operators and maintenance personnel, in an industrial pro...

This paper presents the design and prototype implementation of a service based control system responsible for the material supply operations in assembly lines. Mobile Assistant Units (MAUs) are responsible for the transportation of the consumables from the warehouses to the production stations. A service oriented, web based software has been develo...

This paper proposes a method for task planning in a hybrid assembly cell which includes both Humans and Robots (HR). A model is structured addressing in a unified manner both humans and robots as the cell's resources. The sequence of the HR tasks is structured in three levels. The evaluation of the alternative HR task plans is based on multi-criter...

The Teaching Factory paradigm aims to align manufacturing teaching and training to the needs of modern industrial practice. Future engineers and knowledge workers need to be educated with new curricula in order to cope with the increasing industrial requirements of the factories of the future. The Teaching Factory paradigm comprises the relevant ed...

This study applies an innovative introduction of a learning framework to secondary education, using Virtual Reality (VR) aiming to attract young talent to Manufacturing. To achieve that, the developed approach exposes young students to the concepts of Manufacturing, by using an immersive VR simulation of a manual assembly task in a CAVE. The proced...

Additive Manufacturing (AM) offers great flexibility in producing parts and products that are geometrically complex. Therefore, several design methods have been developed aiming to exploit the AM capabilities and advantages over conventional manufacturing. However, it is crucial to further investigate the potential of AM to enable substitution of e...

This is a study of a Human-Robot Collaboration (HRC) framework for the execution of collaborative tasks in hybrid assembly cells. Robots and humans coexist in the same cell and share tasks according to their capabilities. An intelligent decision-making method that allows human-robot task allocation is proposed and is integrated within a Robot Opera...

The image based systems still have open issues in order to meet the latest manufacturing requirements for simplicity, low cost as well as the limited maintenance requirements. In this direction, there is a method proposed for the recognition of 3D randomly placed objects for eventual robotic handling. The method includes a 2D vision system and is c...

The wide interest of research and industry in the human–robot interaction (HRI) related topics is proportional to the increased productivity and flexibility of the production lines, as it combines human and robot capabilities. This paper presents a review of recent research and progress on HRI, related to task planning/coordination and programming...

A key characteristic for industrial production in the Industry 4.0 paradigm is the connection of physical items like sensors, devices and enterprise assets, connected both to each other and to the Internet. In this Internet of Things environment, things will sense more data, become context-aware and provide added-value information to assist people...

The extraction of assembly information from product data has been researched for the past three decades, mainly due to the advancements in computer performance and CAD-related software. However, the manipulation and processing of CAD data for the automatic generation of assembly information have only been recently researched. This paper presents a...

A theoretical model has been developed for simulating the laser grooving process. It takes into account the interaction among subsequent pulses, the required time for the melting temperature to be reached and the subsequent removal of a finite volume of material during each laser pulse. The model predicts the maximum groove depth that can be achiev...

Increasing the efficiency of gas turbines relies heavily upon machining of Ni-based superalloys. New alloys are continuously being created with increased operating temperature range, which in turn increases the gas turbine efficiency. However, these new-age superalloys are extremely difficult to machine, making production expensive and inefficient....

This paper investigates the flexibility aspects of production systems that use highly interactive and autonomous mobile robotic units. Open communication architectures and ontology technologies enable the accurate representation of robot capabilities. Mobile robots can relocate themselves and support the production process, thus providing a higher...

Future manufacturing challenges have been imposing on the current way of teaching and training the necessity to be competitive in the global market. Recent studies have shown that new teaching curricula are required for the preparation of the future engineers and knowledge workers in order for them to cope with the increasing industrial requirement...

This paper deals with the design of assembly stations, where human-robot collaborative tasks are carried out. Based on the assembly process specifications, different control, safety and operator support strategies have to be implemented in order for the human safety and the overall system's productivity to be ensured. The variability of assembly pr...

This paper discusses a method for the coordination of assembly tasks requiring the cooperation of humans with a robot. A ROS based architecture is used. The assembly sequence of these tasks and their characteristics are modeled in a neutral XML format generated off-line. A ROS based framework in order for different modules to communicate and coordi...

Manual assembly planning methodologies have been in the center of industrial and academic research for many decades, since the manual assembly costs may often account for even half of the total manufacturing expenses. The existing and emerging manufacturing trends, such as mass customization and personalization, require fast responses when it comes...

This article suggests an information system for the support of human operators in an assembly line. The information system utilises mobile devices and a pushlet-based infrastructure for automatically providing the mobile line operators with information in real time. The Radio Frequency Identification technology is used for tracking the location of...

This paper presents an internet-based approach for the performance of assembly line balancing and design in an integrated manner. The resulting software is capable of generating, simulating and evaluating a series of alternative assembly line configurations and is implemented as a cloud service, taking into account diverse market and manufacturing...

Additive manufacturing is a technology rapidly expanding on a number of industrial sectors. It provides design freedom and environmental/ecological advantages. It transforms essentially design files to fully functional products. However, it is still hampered by low productivity, poor quality and uncertainty of final part mechanical properties. The...

In the last decade, numerous learning factories for education, training, and research have been built up in industry and academia. In recent years learning factory initiatives were elevated from a local to a European and then to a worldwide level. In 2014 the CIRP Collaborative Working Group (CWG) on Learning Factories enables a lively exchange on...

The safe and reliable operations in industrial manufacturing processes play a crucial role in the economic productivity. Machining process disturbances such as collision, overload, breakdown, and tool wear tend to cause production system failures. The current study aims at investigating the limitations of tool wear prediction on the milling of CGI...

The manufacturing assembly process includes the manipulation of rigid and non-rigid parts. This paper discusses a method for the estimation of the cables’ shape for robotic manipulation. The paper uses methods that take into account the mechanical behaviour of materials. More specifically, in the framework of static analyses, a higher-order analyti...

This paper presents a framework for the control of autonomous production units for real time reconfiguration of the shop floor. The approach considers a series of highly flexible production solutions including a) autonomous mobile manipulators, which are capable of repositioning themselves on the line, b) flexible grippers with multiple connection...

In this study, an intelligent search algorithm is proposed to define the path that leads to the desired position and orientation of an industrial robot's manipulator end effector. The search algorithm gradually approaches the desired configuration by selecting and evaluating a number of alternative robot's configurations. A grid of the robot's alte...

The aim of this paper is to deal with a method that enables the user to design and configure a production line against multiple-user defined criteria. Machine utilization, investment cost, resource energy consumption, availability and annual production volume are some of the criteria used in the design. The production line design/configuration is a...

This is a technical report of the European FP7 Factory-of-the-Future Programme (FoF-ICT-2011.7, No. 285051). More information: URL: http://www.RLWnavigator.eu/. The RLW Navigator project has developed a few software solution toolkits to facilitate process planning, design, implementation and optimisation of automotive body assembly process with the...

In the globalised and interconnected market, demand fluctuation along with the requirements of high product quality, low cost, short lead time and high customisation may lead to an increase in manufacturing complexity. Over the past years, several methods, following different theories and approaches, have been proposed for the analysis of manufactu...

This paper proposes an approach to the design and operation of assembly systems that include mobile robots. It is based on a semantic model representing the robot/resource skills along with the operations that a resource has to execute. The method is implemented in a system capable of generating the assignment of operations to the proper robotic re...

ICT platforms, in the manufacturing context, provide a number of tools, such as sensors, wireless networks, mobile devices, MES, ERP and information management systems in order to support shop-floor and back-office personnel. There is a need for the vast amount of information gathered and generated by such ICT systems to be utilized in a manner tha...

This paper addresses the problem of modeling, integrating and utilizing existing knowledge for the designing of cooperating robots assembly cells. A knowledge-enabled approach is presented, allowing for the combined use of information pertaining to past engineering projects and of an advanced digital environment. The proposed approach, in the form...

This paper investigates into the use of a dual arm robot system for performing manual assembly operations. The investigation is based on a case study, originating from the final assembly area of an automotive assembly plant. The motivation as well as the benefits derived from the employment of a dual arm robot are discussed. The station layout, too...

This paper presents the vision and architectures, proposed by the EU project ROBO-PARTNER. The project aspires to the integration of the latest industrial automation systems for assembly operations, in combination with human capabilities. Focus is given to combining robot strength, velocity, predictability, repeatability and precision with human in...

Existing and evolving trends and paradigms in manufacturing, such as mass customisation and personalisation, call for better communication among product-production design and customisation and production execution. Specifically, the lack of feedback from and to the shopfloor can lead to lower product quality and increased production times. In state...

Assembly line design methodologies have been extensively researched during the past decades. Various definitions of problems have been established together with different approaches as to the way they are solved. However, in the automotive industry, most companies still use simple tools and methods for the solution of these problems. There can be s...

A numerical study of the laser welding process is presented. The numerical model is based on a combination of the enthalpy method and the finite difference techniques applied to the heat equation that can bypass the manual enforcement of the jump condition at the phase-separating surfaces. Minimal application of the “life and death of elements tech...

This research study deals with the early design and planning of manufacturing systems, following a knowledge reuse approach. The proposed approach introduces a knowledge based framework that facilitates the definition, storage and extraction of knowledge in terms of past production process configurations. The semantic technology and artificial inte...

The aim of this paper is to describe an assembly line paradigm that exploits the latest trends in handling and assembly technologies. Mobile robotic units, flexible and exchangeable end effectors, equipped with automated integration capabilities are used to achieve a highly reconfigurable and autonomous line as opposed to the existing fixed assembl...

Manufacturing systems, in pursuit of cost, time and flexibility optimization are becoming more and more complex, exhibiting a dynamic and non-linear behavior. Unpredictability is a distinct characteristic of such behavior and affects production planning significantly. This paper presents an approach to the assessment of unpredictability in the manu...

Energy efficiency constitutes a very significant factor that requires its inclusion in the manufacturing decision making attributes developing a strategy to produce more with less. The idle state of a machine tool is an inefficient phase. A strategy to increase the energy efficiency of an already balanced production line, using machine tool stand-b...

Energy efficiency has become a very significant factor, requiring its inclusion in the manufacturing decision-making attributes. This paper proposes a generalized approach to manufacturing energy efficiency. The basic element of the approach is the division of energy efficiency definition and study into four manufacturing levels, namely process, ma...

The dynamic manufacturing networks (DMNs) offer a modern approach to managing risks and increasing benefits in the manufacturing sector. The DMNs offer a solution to rapidly and efficiently designing and operating a new manufacturing network, or to reconfiguring an existing one, in order for specific objectives in each situation to be accomplished....

Virtual reality is a key technology for the designing of products through complex human-product interactions. This paper deals with the development of a product design method for complex human-product interactions, using the virtual reality (VR) technology. This VR method uses the graph theory in order for the complexity of the designed product to...

Laser drilling is a thermal process with relatively low energy efficiency since the material removal mechanism is mostly based either on melting or on vaporization. Aiming at the investigation of the laser drilling efficiency, a theoretical both analytical and numerical study of evaporation pulsed laser drilling is presented. The analysis is based...

Manufacturing organizations have been attempting to improve the operation of supply networks through efficient supply chain management. Dynamic manufacturing networks (DMNs) constitute chains of diverse partners, whose operation and interaction may change in a rapid and often not predictable way. While the existing supply chain models are quite sta...

The importance of leveraging manufacturing teaching and training up to the standards of the current and future needs is obvious. Recent studies have pointed out the urgent need for future engineers and knowledge workers to adopt teaching curricula in order to be prepared to cope with the increasing industrial requirements of the factories of the fu...

Laser machining belongs in the large family of material removing or machining processes. It is one of the most widely used thermal energy-based noncontact-type advanced machining processes. Laser beams can be used in many industrial applications, including machining, whereby it constitutes an alternative to traditional material removal techniques a...

The paper deals with modular design architecture and its capabilities for easy and fast customization in products. The basic principles of modularity are mentioned and the most known methodologies and tools for modular product design are reported. The way modularity can facilitate a product's customization is being addressed. With the help of a mod...

SynonymsProfilingDefinitionCold roll forming is a major forming process for the mass production of a variety of complex profiles from a wide spectrum of materials and thicknesses. According to Chryssolouris (2005) and Lange (1985), roll-forming process is classified into the category of sheet metal forming by bending with rotary tool motion. The pl...

This paper addresses the challenge of integrating simulation and augmented reality tools into final assembly operations. The study presented, comprises an assembly sequence generation algorithm, for the creation of assembly sequences and steps, carried out by engineers with the use of CAD data and any additional input concerning the product. This i...

Recent studies have presented clear evidence of the relationship between human capital qualifications and competitiveness. At the same time, there have been frequent reports on the shortage of skilled manufacturing personnel. This paper introduces some approaches to building skills and competences in manufacturing. The importance of human capital s...

This paper demonstrates the added value of using knowledge modeling for the structure of manufacturing indicators. There is a methodology describing the generation of relevant indicator values, based on knowledge modeling. The model has three different layers, starting from a generic one down to an instance layer. This model can be used for reasoni...