An Ontological Approach to Manufacturing Supplier Discovery in Virtual Markets

Manufacturing supply chains are increasingly becoming global, virtual and short-lived in order to improve their agility and dynamic adaptability to rapid changes in today’s volatile market. In this context, online marketplaces for manufacturing services have become attractive venues for rapid development of supply chain relationships. Despite their numerous benefits, the existing online markets have failed in adequately automating the supply chain deployment process. Heavy reliance of the existing online markets on human agents for formulating supplier queries and evaluating the obtained results can be mainly attributed to the informal nature of the information models used in these markets. To enable active involvement of machine agents in supply chain deployment, the underlying information models that support online markets should represent the semantics of information in a formal and machine-interpretable fashion. This paper introduces Manufacturing Service Description Language (MSDL) as a formal ontology for description of suppliers’ capability at different levels of abstraction including process-level, machine-level, and system level. Also, an agent-based framework is proposed in this paper that facilitates automated discovery and evaluation of potential manufacturing partners based on the MSDL description of the services they provide.

Knowledge-Based Task Planning Using Natural Language Processing for Robotic Manufacturing

Robotic alternative to many manual operations falls short in application due to the difficulties in capturing the manual skill of an expert operator. One of the main problems to be solved if robots are to become flexible enough for various manufacturing needs is that of end-user programming. An end-user with little or no technical expertise in robotics area needs to be able to efficiently communicate its manufacturing task to the robot. This paper proposes a new method for robot task planning using some concepts of Artificial Intelligence. Our method is based on a hierarchical knowledge representation and propositional logic, which allows an expert user to incrementally integrate process and geometric parameters with the robot commands. The objective is to provide an intelligent and programmable agent such as a robot with a knowledge base about the attributes of human behaviors in order to facilitate the commanding process. The focus of this work is on robot programming for manufacturing applications. Industrial manipulators work with low level programming languages. This work presents a new method based on Natural Language Processing (NLP) that allows a user to generate robot programs using natural language lexicon and task information. This will enable a manufacturing operator (for example for painting) who may be unfamiliar with robot programming to easily employ the agent for the manufacturing tasks.

Investigations of PMN-PT Single Crystal Performance

Application of new materials, such as PMN-PT single crystals, requires a good understanding of basic material performance under both electrical and mechanical loading. Over the past 5 years the authors have used both computational and experimental techniques to examine the relationships between poling direction, crystal orientation, and electric field actuation. Experiments show mixed results indicating that the relationship between material orientation and loading is more complex than originally imagined. In some cases crack initiation and propagation perpendicular to the applied field was observed within a few thousand cycles but in other cases no failure was observed even after a few hundred thousand cycles despite crack growth in the presence of introduced defects. Computational effort quickly identified a gap between development of theoretical constitutive models that addressed domain switching based nonlinear behavior and what was available in workable form as part of commercial finite element codes. This led to the implementation of a macro-mechanical constitutive model which addresses domain switching, into a commercially available finite element code. The rate independent version has been used to investigate issues of electric field actuation and poling direction. Presented here are insights into the fracture and fatigue behavior of piezoelectric single crystals from both experimental and computational studies.

MTConnect-Based Kaizen for Machine Tool Processes

Kaizen is a part of Lean Manufacturing that focuses on the concept of continuous improvement to reduce waste. For implementing Kaizen on the factory floor, comprehensive and efficient tools for data acquisition, process measurement and analysis are required. The MTConnect open specification provides for cost-effective data acquisition on the manufacturing floor for machine tools and related devices. This paper will look at a Kaizen implementation on the shop floor level for continuous improvement using real-time MTConnect data. The Kaizen transformation of machine data into production knowledge was performed in order to understand energy consumption, asset operation and process performance. The paper takes a detailed examination of the machine tool energy management.

Meshless Integral Method for Analysis of Elastoplastic Geotechnical Materials

The meshless integral method based on regularized boundary equation [1][2] is extended to analyze elastoplastic geotechnical materials. In this formulation, the problem domain is clouded with a node set using automatic node generation. The sub-domain and the support domain related to each node are also generated automatically using algorithms developed for this purpose. The governing integral equation is obtained from the weak form of elastoplasticity over a local sub-domain and the moving least-squares approximation is employed for meshless function approximation. The geotechnical materials are described by pressure-sensitive multi-surface Drucker-Prager/Cap plasticity constitutive law with hardening. A generalized collocation method is used to impose the essential boundary conditions and natural boundary conditions are incorporated in the system governing equations. A comparison of the meshless results with the FEM results shows that the meshless integral method is accurate and robust enough to solve geotechnical materials.

Analysis of the Structure and Evolution of an Open-Source Community

Open-source processes are based on the paradigm of self-organized communities as opposed to traditional hierarchical teams. These processes have not only been successful in the software development domain, but are increasingly being used in the development of physical products. In order to successfully adapt open-source processes to product realization there is a need to understand how open-source communities self-organize and how that impacts the development of the products. Towards the direction of fulfilling this need, we present an analysis of an existing open-source community involved in developing a web-based content-management platform, Drupal. The approach is based on the analysis of networks using techniques such as social network analysis, degree distribution, and hierarchical clustering. Openly available information on the Drupal website is utilized to perform the analysis of the community. The data is transformed into two weighted undirected networks: networks of people and networks of Drupal modules. Both the structure of these networks and their evolution during the past six years are studied. The networks are visualized by mapping them into images. Based on the analysis, it is observed that the structure of the Drupal community has the characteristics of a scale-free network, which is similar to many other complex networks in diverse domains. Finally, key trends in the evolution of the networks are identified and the possible explanations for those trends are discussed.

Supply-Chain Product Development Collaboration Using Configurable Product Platform Models

Collaborative product platform development in the supply chain faces problems not only with inefficient knowledge management and information exchange between collaborating partners, but also with configuration and carryover strategies — both of which result in large amounts of system variants to maintain, and restrained reuse. To address these problems, this article proposes a new, more system-oriented and abstract, knowledge-based approach to define and describe configurable product platforms. A new platform model concept with a new modeling procedure, consisting of linked, fully configurable generic and autonomous sub-systems, has been devised. The model has been implemented as a separate platform configuration (PFC) system within an envisioned product lifecycle management (PLM) system architecture. The PFC system is the common base for system configuration as well as for information and knowledge exchange between collaborating partners. The proposed platform model and collaborative modeling procedure have been partly verified and validated, in cooperation with the industrial partners participating in a joint research project.

Establishing Relationships Between Manufacturing Sustainability and Performance

The current LCA methods assess a product’s sustainability over its full life cycle, cradle-to-grave. While the number(s) obtained detail the contributions a process makes to a product in terms of energy intensity or the generation of wastes, it is insufficient to optimize a process for both sustainability and performance objectives. The Economic Input/Output Life Cycle Analysis (EIO-LCA) was used to investigate whether metrics could be identified which address sustainability — performance issues in materials processing. This method lends itself to the assessment of processes on a unit time basis while allowing for calculation of resources used and byproducts expelled. Productivity of manufacturing processes is also based on time. For example, material removal rate is related to processing feed, speed, and the geometry and tolerances established during design. A scaled waterjet cutting process was tested to investigate the unit time relationships. The EIO-LCA was conducted and the subsequent environmental impact in the form of total energy consumed and equivalent CO2 expelled evaluated per unit time, establishing the relationship to cutting speed. Although this is a static LCA at set conditions, it suggests that relationships can be explored between the regulation of resources, productivity, cost and environmental impact by varying the processing parameters.

APU FMEA Validation and Its Application to Fault Identification

FMEA (Failure Mode and Effects Analysis) is a standard method to characterize and document product and process problems at the design phase. The FMEA is often delivered to the end user along with the product or system. However, once the system is deployed, the corresponding FMEA is rarely validated and updated. This is mainly due to the lack of method to validate and update FMEA. This paper argues that historical maintenance and operational data could be used to help address this problem. Building on data mining and database techniques, the paper introduces a FMEA validation and updating technique. The proposed technique derives statistics from real world historical operation and maintenance data and uses these statistics to update key FMEA parameters such as Failure Rate and Failure Mode Probability. The paper then shows how the validated FMEA can be used with data mining for fault detection and identification of root contributing component for a given failure mode or failure effect. The paper presents the developed methodology for FMEA validation and experimental results for fault identification. The results show that the updated FMEA can provide more reliable and accurate information that could benefit the decision-making process and improve maintenance efficiency.

Closing the Loops Without Human Subjects: A Survey of Control Approaches in Simulation of Human-Artifact Interaction

To include interactions with human users in simulations of the use of products, the most common approach is to couple human subjects to the behavioral product model in the simulation loop using interfaces based on VR and haptics. Replacing human subjects by human models with simulation capabilities could offer a cost-saving alternative. Currently available human models have not yet been deployed this way. This paper explores the possibilities to achieve mutual closed-loop coupling between human models and artifact models for enabling fully software-based interaction simulations. We have not only investigated human control in simulations, but also solutions to include embedded control in artifacts. The paper critically reviews existing (partial) solutions to simulate or execute control behaviors, and to close the control loops we identified in human-artifact interaction simulation. We concluded that closed-loop control of interaction simulations can be achieved by selectively combining existing partial solutions. Inclusion of decision-making appears to be the biggest challenge. Promising solutions are (i) cognitive simulation and (ii) execution of conjectured interactions specified as logical instructions, typically in the form of scenarios. Based on scenarios, which we expect to be more intuitive for designers, a new approach is now being developed.