Human Arm simulation for interactive constrained environment design

During the conceptual and prototype design stage of an industrial product, it is crucial to take assembly/disassembly and maintenance operations in advance. A well-designed system should enable relatively easy access of operating manipulators in the constrained environment and reduce musculoskeletal disorder risks for those manual handling operations. Trajectory planning comes up as an important issue for those assembly and maintenance operations under a constrained environment, since it determines the accessibility and the other ergonomics issues, such as muscle effort and its related fatigue. In this paper, a customer-oriented interactive approach is proposed to partially solve ergonomic related issues encountered during the design stage under a constrained system for the operator's convenience. Based on a single objective optimization method, trajectory planning for different operators could be generated automatically. Meanwhile, a motion capture based method assists the operator to guide the trajectory planning interactively when either a local minimum is encountered within the single objective optimization or the operator prefers guiding the virtual human manually. Besides that, a physical engine is integrated into this approach to provide physically realistic simulation in real time manner, so that collision free path and related dynamic information could be computed to determine further muscle fatigue and accessibility of a product designComment: International Journal on Interactive Design and Manufacturing (IJIDeM) (2012) 1-12. arXiv admin note: substantial text overlap with arXiv:1012.432

Methods of representing the structure of complex industrial products on computer files, to facilitate planning, costing and related management tasks : a thesis presented in fulfilment of the requirements for the degree of Master of Technology in Manufacturing and Industrial Technology at Massey University

When the original concepts for the computerisation of product structures were developed in the late 1960's the available computer power was very limited. A modularisation technique was developed to address the situation in which a number of similar products were being manufactured. This technique tried to rationalise these products into family groups. Each member of the family differed from the others due to the possession of different features or options. However there was also a high degree of commonality to give the product membership of the family. Modularisation involved the identification of the options and features providing the variability. Those parts remaining tended to be common to all members of the family and became known as the common parts. Separate Bills of Material (BOMs) were set up for each of the identified options or features. Another BOM was set up for the common parts. The simple combination of the required options and/or features BOMs with the common parts BOM specified a product. Computer storage requirements and redundancy were reduced to a minimum. The Materials Requirements Planning (MRP) system could manipulate these option and feature BOMs to over plan product variability without over planning the parts common to all members. The modularisation philosophy had wide acceptance and is the foundation of MRP training. Modularisation, developed for MRP, is generally parts orientated. An unfortunate side effect tends to be the loss of product structure information. Most commercial software would list 6 resistors, Part No. 123, in the common parts BOM without concern as to where the resistors are fitted. This loss of product structure information can hide the fact that two products using these 6 resistors 'in common' are in fact different as they do not use the resistors in the same 6 places. Additional information must be consulted to enable the correct assembly of the 'common' portion of these products. The electronics industry is especially affected by this situation. This industry has changed considerably since the late 1960's. Product variability can be very high. Changes and enhancements are a constant factor in products having a relatively short life span. The modularisation technique does not have a good mechanism for the situation where an option itself has options or features. This situation can exist down a number of layers of the family tree structure of an electronics product. Maintenance of these BOMs is difficult. Where there are options within options the designers and production staff need to know the inter-relationship of parts between options to ensure accuracy, compatibility and plan assembly functions. The advent of computerised spreadsheets has made the maintenance of this type of product structure information easier. This matrix is another separate document which must be maintained and cross checked. It will inevitably differ from the BOMs periodically. This thesis develops a product structure Relational BOM based on the matrix for the family of products. The processing power of the 1990's computer is fully utilised to derive the common parts for any or all of the selected products of the family. All product structure information is retained and the inter-relationship of parts is highly visible. The physical maintenance of the BOMs is simple. The BOM serves all purposes without the need for supplementary information. It is fully integrated into the Sales Order Entry , MRP, Costing, Engineering Design and Computer Aided Manufacturing (CAM) systems. This technique has been proven by being the only system used in one Electronics Design and Manufacturing organisation for over 1 year without any major problems. As described in Section 1.6 user satisfaction has been high. The response of the users to the suggestion 'lets buy an "off the shelf" package' is very negative, as it would not incorporate this BOM system. Users have expressed the opinion that EXICOM could not continue, with present staffing levels, using the traditional BOM structure

Concurrent Design of Assembly Plans and Supply Chains: Models, Algorithms, and Strategies.

Assembly planning and supply chain designs are two inter-dependent activities in product development. The traditional sequential approach of designing the supply chain after completing assembly planning results in long lead time for product realization and sub-optimal product cost. The weakness of the sequential method is exacerbated nowadays as product proliferation brings more challenges to assembly system design and supply chain management. Making concurrent decisions on assembly plans and supply chain configurations is a desirable strategy. However, due to the complexity of both assembly representations and supply chain modeling, there have been limited systematic models, optimization algorithms, or deep understanding of the interaction between assembly-plan and supply-chain designs. This dissertation first analyzes and compares existing assembly representation methods. Hyper AND/OR Graph (HAG) is then developed to incorporate both assembly planning and supply chain configuration information by adding one additional layer representing supplier information on top of a typical assembly AND/OR graph. Based on HAG, a DP based algorithm with a polynomial complexity for typical assembly products is developed to generate the assembly plans and supplier assignment at the optimal cost. For the problem with a lead time constraint, a revised DP algorithm with a pseudo-polynomial complexity is also presented. Under the scenario of product family designs, an investigation is carried out on the optimal strategies to design assembly supply chains when commonality is limited between products in the family. The impact of product variety on safety inventory is derived and then evaluated with a performance measure. Strategies of prioritized differentiation and branch balancing are suggested for optimal process sequencing and assembly decomposition. The outcome of this research are threefold: (1) it establishes a foundation for the research on integrated designs of assembly plans and supply chains as well as other concurrent design problems; (2) it offers a tool for integrated assembly plan and supply chain designs using which manufacturers can shorten the product development time, lower the product cost, and increase the responsiveness to fluctuations in supply chains; and (3) it provides a measure of the impact of product variety on inventory and insightful strategies to manage complicated assembly supply chains.PhDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133210/1/hekuang_1.pd

Development of a manufacturing feature-based design system

Traditional CAD systems are based on the serial approach of the product development cycle: the design process is not integrated with other activities and thus it can not provide information for subsequent phases of product development. In order to eliminate this problem, many modern CAD systems allow the composition of designs from building blocks of higher level of abstraction called features. Although features used in current systems tend to be named after manufacturing processes, they do not, in reality, provide valuable manufacturing data. Apart from the obvious disadvantage that process engineers need to re-evaluate the design and capture the intent of the designer, this approach also prohibits early detection of possible manufacturing problems. This research attempts to bring the design and manufacturing phases together by implementing manufacturing features. A design is composed entirely in a bottom-up manner using manufacturable entities in the same way as they would be produced during the manufacturing phase. Each feature consists of parameterised geometry, manufacturing information (including machine tool, cutting tools, cutting conditions, fixtures, and relative cost information), design limitations, functionality rules, and design-for-manufacture rules. The designer selects features from a hierarchical feature library. Upon insertion of a feature, the system ensures that no functionality or manufacturing rules are violated. If a feature is modified, the system validates the feature by making sure that it remains consistent with its original functionality and design-for-manufacture rules are re-applied. The system also allows analysis of designs, from a manufacturing point of view, that were not composed using features. In order to reduce the complexity of the system, design functionality and design-for manufacture rules are organised into a hierarchical system and are pointed to the appropriate entries of the feature hierarchy. The system makes it possible to avoid costly designs by eliminating possible manufacturing problems early in the product development cycle. It also makes computer-aided process planning feasible. The system is developed as an extension of a commercially available CAD/CAM system (Pro/Engineer), and at its current stage only deals with machining features. However, using the same principles, it can be expanded to cover other kinds of manufacturing processes

The Utilization of Normalized Difference Vegetation Index to Map Habitat Quality in Turin (Italy)

The integration of ecosystem service mapping in decision-making is crucial to place effective urban design and sustainable planning solutions. Nonetheless, often ecosystem service maps are the product of different data inputs that influences the final modeling output thus affecting final decisions, especially when a finer and site-specific assessment is required to design practical and effective solutions. In this work, the city of Turin (Northwest Italy) was selected as a test site for an empirical experiment of ecosystem service mapping using the software Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST): two habitat quality models of the city were compared in a Geographic Information System environment, the first using the “traditional” sensitivity employed during the LIFE SAM4CP European research while the second using the natural difference vegetation index to re-assign the sensitivity scores. Results demonstrate that the integration of site-specific information in the habitat quality input model generates a different result, which is capable of differentiating all those dense built-up areas of the dense settlement system that provide ecosystem supporting functions at the city-level. These differences were analyzed to define new green hotspots in the compact city while furnishing a new perspective for sustainable city planning

An implementation model of a quality management information scheme for cellular manufacturing environments

As today's global competition grows in manufacturing industries companies are forced to work smart in all areas of operations, starting with suppliers and ending with customers. This competition in general requires firms to improve market responsiveness, product quality, use computerised information systems for production planning and control, have more rapid changeovers, reductions in setup times, work-in-progress reduction and hence throughput time reduction. In order to accomplish these formidable tasks, there are a number of management philosophies available for manufacturing companies. These include just-in-time, flexible manufacturing systems, computer integrated manufacturing, total quality management, concurrent engineering. Implementation of these philosophies, however, requires mass mobilisation encompassing many areas of operations such as production, sales and marketing, suppliers, finance, customer servicing, product design and method engineering, maintenance, personnel and training, etc. This thesis details a study which evaluates the total quality management philosophy in cellular manufacturing environment. Following this evaluation, a quality management information scheme, which is structured and integrated, has been produced using the Manufacturing Systems Analysis and Design Method. In order to manage smoothly this mobilisation and incorporate the scheme to other integrated functional areas, a new approach namely the Activity Based Implementation (ABI) has also been produced. Justification of the model from various points of view has shown that the model is expected to address a considerable gap in the area concerned. The model was designed to be used as an integrated part of a system or as a stand-alone scheme by quality practitioners, the management board of organisations implementing TQM and quality management researchers

The Design of a Monitoring Application System for The Production of Foam Products Using the UML And Waterfall Methods

The development of information technology, which is followed by a higher level of competition in the foam product industry, encouraging companies to manage their company's resources properly and to plan effective, systematic and mature activities within the company. As a company with a variety of products, the most dominant problem is in the productivity process. Production is the most important part of a manufacturing company, where in carrying out its production activities this company produces based on orders from customers (Job Orders). And the problems that often occur are planning revisions in the midst of production and changing production schedules between groups (lines), delays in production planning in terms of prioritizing planning, and still being done manually in making daily reports. By implementing monitoring, which is the supervision and control of an activity where measurements and evaluations are completed repeatedly from time to time, monitoring is carried out for the purposes of the company and to maintain ongoing management. Monitoring will provide information about the status and trend of production activities towards the company's goals. The solution to this production problem is to build a web-based foam product production monitoring system application using the Waterfall method which is integrated with UML the method used is use case diagrams, activity diagrams, sequence diagrams, class diagrams and component diagrams and software development with PHP and MySQL technology. With Black box testing, it is proven that the design of this foam production monitoring system application can assist the company's foam product production activities in fulfilling customer orders and accurate reports so that it becomes effective and efficient. in improving the productivity and performance of the company

A Boolean Algebra Approach To High-level Process Planning

One of the most daunting challenges in Computer Integrated Manufacturing (CIM) is bridging the gap between Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM). Many specific approaches have been developed for limited manufacturing domains. For example, a solid model may be directly converted into Numerical Control (NC) code for a computerized milling machine. But, when we try to extend the planning to cover a number of domains, there are no satisfactory techniques. This still leaves many unresolved problems when converting a product from design features to manufacturing features.;Computer Aided Process Planning (CAPP) is the umbrella term for automated approaches to determining production process parameters from a design. This thesis has a description of the various approaches and methods used when constructing these systems. For the most part, the existing research has focussed on limited production domains, while there is a definite need for a system that can combine a large number of different manufacturing processes. Such an approach is presented in this thesis.;This approach begins with a design stored in sets that are linked together with Boolean equations. The information in this representation can be collected using modern solid modeling systems. The primary difference is that current CAD systems perform operations and then discard the information provided by the user. When this information is kept, it provides a powerful tool for reasoning about manufacturing a product.;The design is loaded into a hierarchical, non-linear planning system. The planner first looks for assemblies and reused features. Each of the features and assemblies are examined separately. In a first pass, the equation for a part is examined for known forms in the equation using templates. If a template is matched to part of an equation, then corresponding production rules are examined. These rules are of the form \u27if {dollar}\langle\rm conditions\rangle{dollar} then {dollar}\rm\langle actions\rangle{dollar}\u27. The planner will find a number of alternatives for each operation, and try to plan from beginning to end. If for some reason the planner is not able to complete the plan, it will backtrack and try another alternative. If the planner is unable to find a satisfactory plan, then it will simplify the Boolean equation and begin planning again.;The planner\u27s capabilities are demonstrated through the use of examples. The results show that the planner is able to plan with mixed production technologies, select plans on the basis of cost, generate alternative operations, deal with new technologies, and recover from failures. The thesis is concluded with a discussion of the method in general, including some of the future developments, some of the shortcomings, and some of the outstanding research questions for the method

A novel and smart interactive feature recognition system for rotational parts using a STEP file

Sharing product design information with other downstream applications, such as process planning, is a major barrier to develop an integrated manufacturing system. Part of this shortcoming is due to the difference in product data descriptions, since a design is geometry based, whereas process planning is manufacturing feature based. The implementation of automatic feature recognition (AFR) techniques is considered an indispensable concept for transferring product data between computer-aided design (CAD) and automatic computer-aided process planning (ACAPP). This is accomplished using one of the international Product Data Exchange (PDE) standards, such as DXF, IGES, or STEP files. Despite different AFR techniques and systems having been developed to serve this aim, each of them has limitations. The most important limitation is that each system is restricted to a specific set of predefined manufacturing features. This means that even when the system tries to cover as many as possible of the existing features that are predefined, it is always possible to create a new feature based on the specific requirements and designer creativity. Consequently, the new feature is not included in the compiled database and, hence, will not be recognised. This paper presents a novel and smart interactive AFR (SI-AFR) methodology for recognising the features of rotational parts, taking a STEP AP203, AP214, or AP242 file as an input to the system. This has been written using C# coding to extract the features’ geometrical and topological information from a STEP file, building a database containing a set of 54 predefined features, whilst also smartly learning how to recognise new features and adding them to the set. Several examples have been processed for this paper to validate the system, and based on the results, it is anticipated that it will lead to the launching of a new generation of feature recognition systems.Republic of Iraq Ministry of Higher Education & Scientific Research; The University of Technology, Baghda

The Design and Implementation of a bespoke Enterprise Resource Planning System (ERP) for an acoustical engineering company

This paper will describe the tasks completed so far as part of a Knowledge Transfer Partnership between the University of Hertfordshire and Acoustical Control Engineers (ACE) a ‘small and medium sized enterprise’ (SME) based in Cambridgeshire, UK. ACE’s 25 personnel design, manufacture and install noise and vibration control systems to solve a wide range of acoustic problems. The projects undertaken include acoustic enclosures for supermarket refrigeration plant and for generators used in many situations, together with other more diverse applications such as controlling noise in the workplace and even on a luxury boat. Before the current KTP project the company used some partially computerised systems consisting of spreadsheets to perform acoustic analyses, pricing and project management functions supplemented with a paper based system to ‘fill the gaps’. Enterprise Resource Planning (ERP) systems provide an integrated database for all parts of the organisation allowing decisions to be based on a complete understanding of the organisation’s information, avoiding the problems due to duplication of data and ensuring that the consequences of decisions in one part of the organisation are reflected in the planning and control systems of the rest of the organisation. ERP systems became popular from the 1990’s mainly in relatively large organisations due to the complexity and cost of these systems. This project is unusual in that rather than adapting an off-the-shelf ERP solution to ACE’s very specific and specialised requirements we are taking an ERP development approach in an SME whose legacy systems are made up of spreadsheet and paper based systems. For the software development an Agile approach has been used. Agile involves software development methods based on iterative and incremental development. The initial attempt was to start developing the ERP from an Open Source ERP Source Code; however this effort was futile as a result of the bespoke nature of ACE’s business and product lines. Mapping ACE’s data model to the database which any existing ERP system could be adapted to, proved to be a very difficult problem. Therefore, developing the ERP from first principles was inevitable. Several of the ERP modules have been developed, user training has taken place and the core modules have been signed off. The project is due to complete in September 2014 and by this time we will have further information on how the ERP system has increased the competitiveness of the company, as well as experience of introducing an ERP into an SME. However, as would be expected the work undertaken developing the system so far has had several significant effects on ACE and acted as a catalyst for change in various parts of ACE’s business.Non peer reviewe