A knowledge based expert system for moulded part design

In today's competitive market many consumer products are designed with complex curved shapes to meet customers' demands for styling and ergonomics. These styled products are commonly manufactured using moulding processes because they can produce a wide range of freeform shapes at relatively low cost. However, although injection moulding and metal casting allow a great deal of design freedom they also make significant demands on the designer to ensure that parts are designed with due regard for manufacturability. This paper describes a knowledge based moulding advisor that has been developed to provide design for moulding advice to designers during the design process. The main contributions of the research are the development of a hierarchical knowledge representation to allow moulding advice to be generated at different levels of detail and the integration of the expert system with a geometric part description extracted from a Computer Aided Design (CAD) solid model. A demonstrator for the manufacturing advisor has been implemented using the expert system shell CLIPS and integrated with CAD using feature recognition. The moulding advisor is able to generate tailored design for moulding advice for a range of manufacturing processes and materials and evaluate the manufacturability of a designed part at the feature level. The paper provides a case study for a simple moulded test part

A Student-Centered Learning Approach to Design for Manufacturability: Meeting the Needs of an Often- Forgotten Customer

A hands-on learning module was implemented at Marquette University in 2012 to teach biomedical engineering students about basic manufacturing processes, lean manufacturing principles, and design for manufacturability. It incorporates active and student-centered learning as part of in-class assembly line simulations. Since then, it has evolved from three class periods to five. The module begins with two classroom presentations on manufacturing operations and electronics design, assembly, and testing. Students then participate in an in-class assembly line simulation exercise where they build and test an actual product per written work instructions. They reflect on this experience and suggest design and process changes to improve the assembly line process and quality, save time, and reduce cost and waste. At the end of the module students implement their suggested design and process improvements and repeat the exercise to determine the impact of their improvements. They learn of the importance of Design for Manufacturability, well-written work instructions, process design, and designing a product not only for the end user, but also for the assemblers and inspectors. Details of the module, and its implementation and assessment are presented along with student feedback and faculty observations

Observing Suppliers observing Early Supplier Involvement: An Empirical Research based upon the Social Systems Theory of Niklas Luhmann.

supplier, involvement, Luhmann

Conceptual Graphs in CAD

This paper elaborates on the use of conceptual graphs in a prototype of a computer based support system for re-design. Re-design support involves the modelling of assemblies and components. The requirements of the components to be modelled are a compromise between the functioning of the assembly and the manufacturability of the individual components. Conceptual graphs provide for an elegant way of representing both functioning and manufacturing aspects. In the prototype system, conceptual graphs are used for representing and defining assemblies, components and features as well as the relations between these entities. Constraints, such as kinematic, tolerance and manufacturing constraints are also represented using conceptual graphs

An extensible manufacturing resource model for process integration

Driven by industrial needs and enabled by process technology and information technology, enterprise integration is rapidly shifting from information integration to process integration to improve overall performance of enterprises. Traditional resource models are established based on the needs of individual applications. They cannot effectively serve process integration which needs resources to be represented in a unified, comprehensive and flexible way to meet the needs of various applications for different business processes. This paper looks into this issue and presents a configurable and extensible resource model which can be rapidly reconfigured and extended to serve for different applications. To achieve generality, the presented resource model is established from macro level and micro level. A semantic representation method is developed to improve the flexibility and extensibility of the model

Design of a compact objective for SWIR applications

Lately the short-wave infrared (SWIR) has become very important due to the recent appearance on the market of the small detectors with a large focal plane array. Military applications for SWIR cameras include handheld and airborne systems with long range detection requirements, but where volume and weight restrictions must be considered. In this paper we present three different designs of telephoto objectives that have been designed according to three different methods. Firstly the conventional method where the starting point of the design is an existing design. Secondly we will face design starting from the design of an aplanatic system. And finally the simultaneous multiple surfaces (SMS) method, where the starting point is the input wavefronts that we choose. The designs are compared in terms of optical performance, volume, weight and manufacturability. Because the objectives have been designed for the SWIR waveband, the color correction has important implications in the choice of glass that will be discussed in detai

Design Management Capability in Entrepreneurship: A Case Study of Xiaomi

In recent years, entrepreneurship has become a popular topic and attracted many young people to start their own companies. In entrepreneurship, design was generally viewed as essential to innovation, replacing the conventional role of the engineer. Unlike traditional businesses, which generally take a longer time to become established in the more stable economic context of mass-production, current start-ups have to face fierce competition and have the tendency to expand rapidly and accommodate the dynamic business environment. Consequently, design management is considered to be crucial to business growth, since it contributes to both competitive advantages and strategic flexibility. However, start-up companies are well-known for their high failure ratio. This triggered our initial research question: what is the role of design in a start-up to support it in achieving success? Through a case study of Xiaomi, a well-known successful entrepreneurship in China, the new capabilities of entrepreneurial design management were reported. It was further classified into three key topics in line with the three stages of entrepreneurial business development. Difference with design management capabilities reported in previous studies, the new capabilities show the dynamic nature of entrepreneurial design management

Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990'

Review of research in feature-based design

Research in feature-based design is reviewed. Feature-based design is regarded as a key factor towards CAD/CAPP integration from a process planning point of view. From a design point of view, feature-based design offers possibilities for supporting the design process better than current CAD systems do. The evolution of feature definitions is briefly discussed. Features and their role in the design process and as representatives of design-objects and design-object knowledge are discussed. The main research issues related to feature-based design are outlined. These are: feature representation, features and tolerances, feature validation, multiple viewpoints towards features, features and standardization, and features and languages. An overview of some academic feature-based design systems is provided. Future research issues in feature-based design are outlined. The conclusion is that feature-based design is still in its infancy, and that more research is needed for a better support of the design process and better integration with manufacturing, although major advances have already been made