Multidisciplinary interface model for design of mechatronic systems

The design of mechatronic systems is based on the integration of several disciplines, such as mechanical, electrical and software engineering. How to achieve an integrated multidisciplinary design during the development process of mechatronic systems has attracted the attention of both academia and industry. However, solutions which can fully solve this problem have not been proposed by now. The concept of multidisciplinary interface represents the logical or physical relationship integrating the components of the mechatronic system or the components with their environment. As the design of mechatronic systems is a multidisciplinary work, the multidisciplinary interface model can be considered as one of the most effective supports to aid designers for achieving the integrated multidisciplinary design during the development process. The paper presents a multidisciplinary interface model for design of mechatronic systems in order to enable the multidisciplinary integration among design team members from different disciplines. On the one hand, the proposed model ensures the consistency of interface defined by the designers. On the other hand, it helps the designers to guarantee the different components integrate correctly. The interface model including three concepts: classification, data model and compatibility rules. The multidisciplinary interface model is implemented by a case study based on a 3D measurement system.     

Automated generation of multiphysics simulation models to support multidisciplinary design optimization

To ensure a consistent design representation for serving multidisciplinary analysis, this research study proposes an intelligent modeling system to automatically generate multiphysics simulation models to support multidisciplinary design optimization processes by using a knowledge based engineering approach. A key element of this system is a multiphysics information model (MIM), which integrates the design and simulation knowledge from multiple engineering domains. The intelligent modeling system defines classes with attributes to represent various aspects of physical entities. Moreover, it uses functions to capture the non-physical information, such as control architecture, simulation test maneuvers and simulation procedures. The challenge of system coupling and the interactions among the disciplines are taken into account during the process of knowledge acquisition. Depending on the domain requirements, the intelligent modeling system extracts the required knowledge from the MIM and uses this first to instantiate submodels and second to construct the multiphysics simulation model by combining all submodels. The objective of this research is to reduce the time and effort for modeling complex systems and to provide a consistent and concurrent design environment to support multidisciplinary design optimization. The development of an unstable and unmanned aerial vehicle, a multirotor UAV, is selected as test case. The intelligent modeling system is demonstrated by modeling thirty-thousand multirotor UAV designs with different topologies and by ensuring the automatic development of a consistent control system dedicated for each individual design. Moreover, the resulting multiphysics simulation model of the multirotor UAV is validated by comparing with the flight data of an actual quadrotor UAV. The results show that the multiphysics simulation model matches test data well and indicate that high fidelity models can be generated with the automatic model generation process.     

LOcal Uncertainty Processing (LOUP) method for multidisciplinary robust design optimization

In this paper, we develop an easy-to-implement approximate method to take uncertainties into account during a multidisciplinary optimization. Multidisciplinary robust design usually involves setting up a full uncertainty propagation within the system, requiring major modifications in every discipline and on the shared variables. Uncertainty propagation is an expensive process, but robust solutions can be obtained more easily when the disciplines affected by uncertainties have a significant effect on the objectives of the problem. A heuristic method based on local uncertainty processing (LOUP) is presented here, allowing approximate solving of specific robust optimization problems with minor changes in the initial multidisciplinary system. Uncertainty is processed within the disciplines that it impacts directly, without propagation to the other disciplines. A criterion to verify a posteriori the applicability of the method to a given multidisciplinary system is provided. The LOUP method is applied to an aircraft preliminary design industrial test case, in which it allowed to obtain robust designs whose performance is more stable than the one of deterministic solutions, relatively to uncertain parameter variations.     

A dimensional tolerancing knowledge management system using Nested Ripple Down Rules (NRDR)

This paper proposes to use a knowledge acquisition (KA) approach based on Nested Ripple Down Rules (NRDR) to assist in mechanical design focusing on dimensional tolerancing. A knowledge approach to incrementally model expert design processes is implemented. The knowledge is acquired in the context of its use, which substantially supports the KA process. The knowledge is captured which human designers utilize in order to specify dimensional tolerances on shafts and mating holes in order to meet desired classes of fit as set by relevant engineering standards in order to demonstrate the presented approach. The developed dimensional tolerancing knowledge management system would help mechanical designers become more effective in the time-consuming tolerancing process of their designs in the future.     

VERSION CONTROL OF DISTRIBUTED EDBMS FOR CSCW

ＶＥＲＳＩＯＮＣＯＮＴＲＯＬＯＦＤＩＳＴＲＩＢＵＴＥＤＥＤＢＭＳＦＯＲＣＳＣＷ￥ＷａｎｇＱｉａｎｐｉｎｇ；ＬｉｎＺｏｎｇｋａｉ；ＧｕｏＹｕｃｈａｉ（ＣＡＤＬａｂ．，ＩｎｓｔｉｔｕｔｅｏｆＣｏｍｐｕｔｉｎｇＴｅｃｈｎｏｌｏｇｙＡｃａｄｅｍｉａＳｉｎｉｃ...     

Design Scenarios: Enabling transparent parametric design spaces

This paper presents a novel methodology called Design Scenarios (DSs) intended for use in conceptual design of buildings. DS enables multidisciplinary design teams to streamline the requirements definition, alternative generation, analysis, and decision-making processes by providing a methodology for building and managing requirements driven design spaces with parametric Computer Aided Design (CAD) tools. DS consists of four interdependent models: (1) Requirements Model – stakeholders and designers explicitly define and prioritize context specific design requirements; (2) Scenarios Model (SM) – designers formally transform these requirements into actions necessary to achieve them, and determine the geometric and material parameters, interrelationships, and potential conflicts; (3) Parametric Process Model (PPM) – CAD experts build and represent the technical implementation of a SM in a parametric model to enable design teams to manage and communicate its CAD models; (4) Alternative Analysis Model – analyze and visually report performance back to the designers and stakeholders. This paper motivates the need for the DS methodology thorough an industry case study, and establishes points of departure for the methodology through literature review. Next, the paper details the elements and methods in the methodology, describes its implementation into a software prototype, provides an illustrative example to explain, and an industry test case to validate how DS can potentially enable multidisciplinary teams to generate and communicate larger and better performing design spaces more efficiently than with traditional methods.     

谈设计管理学对设计师的指导作用

设计管理学是一门有关如何管理设计的应用学科,好的设计管理在设计项目中起着重要作用。设计项目由客户、企业或者组织机构提供资金,由设计师、设计团队或设计咨询公司共同完成。而除了设计经理人统领整个设计项目之外,设计师对设计管理的理解能力与应用程度也决定了设计项目的成败。在本论文中详细阐述设计管理在设计项目中对设计师的指导作用及重要意义。     

Improving Web site design

Using quantitative measures of the informational, navigational, and graphical aspects of a Web site, a quality checker aims to help nonprofessional designers improve their Web sites. As part of the WebTango project, we explore automated approaches for helping designers improve their sites. Our goal is to create an interactive tool that helps steer occasional Web site builders away from bad designs and toward better ones - a "quality checker" tool, analogous to a grammar checker in a word processor. What distinguishes our work from most others is that this tool is based on empirically derived measures computed over thousands of Web pages. We converted these measures, which characterize the informational, navigational, and graphical aspects of a Web site, into profiles for a variety of site types. Our rudimentary design-checking tool uses these profiles to assess Web site designs; future versions will also suggest design improvements     

软件子项目的在线版本的版本升级

参考工程配置的版本分类法[2],可按软件配置的进化过程将软件配置的版本分为设计版本、在线版本和项目版本,本文重点讨论在项目/子项目模式下,受控库中的子项目的在线版本的版本升级。     

Design and implementation of an agent-based collaborative product design system

The evolution of computer science and technology has brought new opportunities for multidisciplinary designers and engineers to collaborate with each other in a concurrent and coordinated manner. The development of computational agents with unified data structures and software protocols contributes to the establishment of a new way of working in collaborative design, which is increasingly becoming an international practice. In this paper, based on the analysis of the dynamic nature of collaborative design process, a new framework for collaborative design is described. This framework adopts an agent-based approach and relocates designers, managers, systems, and the supporting agents in a unified knowledge representation scheme for product design. In order to model the constantly evolving design process and the rationales resulted from design collaboration, a Collaborative Product Data Model (CPDM) and a constraint-based Collaborative Design Process Model (CDPM) are proposed to facilitate the management and coordination of the collaborative design process as well as design knowledge management. A prototype system of the proposed framework is implemented and its feasibility is evaluated using a real design scenario whose objective is designing a set of dining table and chairs.     

Structural shape optimization using Cartesian grids and automatic <Emphasis Type="Italic">h</Emphasis>-adaptive mesh projection

We present a novel approach to 3D structural shape optimization that leans on an Immersed Boundary Method. A boundary tracking strategy based on evaluating the intersections between a fixed Cartesian grid and the evolving geometry sorts elements as internal, external and intersected. The integration procedure used by the NURBS-Enhanced Finite Element Method accurately accounts for the nonconformity between the fixed embedding discretization and the evolving structural shape, avoiding the creation of a boundary-fitted mesh for each design iteration, yielding in very efficient mesh generation process. A Cartesian hierarchical data structure improves the efficiency of the analyzes, allowing for trivial data sharing between similar entities or for an optimal reordering of the matrices for the solution of the system of equations, among other benefits. Shape optimization requires the sufficiently accurate structural analysis of a large number of different designs, presenting the computational cost for each design as a critical issue. The information required to create 3D Cartesian h-adapted mesh for new geometries is projected from previously analyzed geometries using shape sensitivity results. Then, the refinement criterion permits one to directly build h-adapted mesh on the new designs with a specified and controlled error level. Several examples are presented to show how the techniques here proposed considerably improve the computational efficiency of the optimization process.     

Modeling and analyzing dynamic social networks for behavioral pattern discovery in collaborative design

As a newly-developed information exchange and management platform, Building Information Modeling (BIM) is altering the way of collaboration among multi-engineers for civil engineering projects. During the BIM implementation, a large number of event logs are automatically generated and accumulated to record details of the model evolution. For knowledge discovery from huge logs, a novel BIM event log mining approach based on the dynamic social network analysis is presented to examine designers’ performance objectively, which has been verified in BIM event logs about an ongoing year-long design project. Relying on meaningful information extracted from time-stamped logs, networks on the monthly interval are built to graphically represent information and knowledge sharing among designers. Special emphasis is put on measuring designers’ influence by a defined new metric called “impact score”, which combines the k-shell method and 1-step neighbors to achieve comparatively low computational cost and high accurate ranking. Besides, an emerging machine learning algorithm named CatBoost is utilized to predict designers’ influence intelligently by learning features from both network structure and human behavior. It has been found that twelve networks can be easily distinguished into two collaborative patterns, whose characteristics in both network structures and designers’ behaviors are significantly different. The most influential designers are similar within the same group but varied from different groups. Extensive analytical results confirm that the method can potentially serve as month-by-month feedback to monitor the complex modeling process, which further supports managers to realize data-driven decision making for better leadership and work plan towards an optimized collaborative design.     

New reasoning algorithm for assembly tolerance specifications and corresponding tolerance zone types

When designing a mechanical product, how to determine its assembly tolerance specifications (ATS) and tolerance zone types (TZT) is a complex design problem, in which designers need to consider comprehensively the functional requirement, geometric feature, tolerance principle, and so on. Therefore, it has high requirements for designers. Meanwhile, the design and development of a complex assembly need to be done jointly by designers. This will cause difficulties for the overall coordination of tolerance design, which affects the quality and efficiency of product development. In order to reduce the uncertainty of ATS and TZT design, and to adapt to the requirements of digital design, a new reasoning algorithm for the automatic generation of ATS and TZT is presented. Polychromatic sets theory (PST) can provide a more formal approach to describe research objects and the relationships among them. Based on PST, this method establishes reasoning relation matrices to represent the relations among research objects, such as assembly feature, assembly constraint type, datum reference frame and tolerance zone type. Therefore, it can use a unified formal mathematical model to describe the whole reasoning process from assembly to ATS and TZT. This method realizes the systematization and computerization of ATS and TZT design, which can help designers to achieve the coordination and coherence of tolerance design. This method facilitates knowledge management and improves reasoning quality and efficiency. ATSs and TZTs generated by this method meet the functional requirements of product and are in accord with the tolerance standards in ISO/ASME. Furthermore, the method only requires a little geometric information and is consistent with the designers’ way of thinking, which shows good applicability for the practical design of ATS and TZT. Finally, the reasoning steps of ATSs and TZTs are demonstrated by means of an example.     

Optimal design of controlled multibody dynamic systems for performance,robustness and tolerancing

The multidisciplinary design approach has gained increasing popularity in recent years due to its ability to deal with conflicting design requirements imposed by discipline-specific objectives. The traditional design process involving multiple disciplines is typically a sequential process where the design objectives are met one at a time in a sequence of designs. However, in doing so, unnecessary limitations are imposed on the design parameters and the final design is far from being optimal. The effectiveness of integrated design methodology has been proven and such designs are being obtained in many applications. However, most of the work in this area has been problem and/or system specific and does not address important manufacturing considerations, such as tolerance allocation, robustness with respect to machining tolerances, etc. The results presented in this paper are intended to contribution towards filling these gaps. In particular, the new approach will help designers avoid a common known pitfall of performance optimization, i.e. the fact that designs that are optimized for performance alone are notoriously sensitive to deviations from the nominal design. Thus, optimizing for performance alone leads to designs that fall below acceptable standards of robustness; they are also expensive to manufacture because the tolerances must be kept very tight to ensure acceptable performance. The approach presented here will allow the user to systematically tradeoff performance versus robustness and tolerancing concerns. A proof-of-concept example that was solved to evaluate this methodology is also presented in this paper. This example provides a convincing demonstration of the fact that small sacrifices in performance can yield huge benefits in the other areas, provided a methodology is available for making these tradeoffs in a systematic way. This especially can be used by designers in various fields such as automotive, aerospace, deployable structures, machine tools (including hexapods), robotic systems, precision machinery, etc.     

Collaborative intelligent CAD framework incorporating design history tracking algorithm

This paper shows a new and efficient collaborative intelligent Computer Aided Design (CAD) framework in a theoretical study. While other collaborative CAD frameworks or protocols focus on decreasing the waiting time for updating design or communication methods for design review among collaborative designers, the suggested collaborative design protocol determines the next design ownership criterion with the objective of minimizing redundant design stages and design bottlenecks using the design history. In addition, the suggested framework generates an efficient reverse-engineered process for achieving the final design target with identification of redundant designs and how these can be prevented while resolving other existing collaborative design issues. As a design history mechanism, a feature-based design history tracking algorithm is suggested. In each design stage, the modeling activities are mapped to the related geometry and topology information. This information is reasoned into features using the feature design history graph (FDHG) and modified attribute adjacency graph (MAAG). The identified features are utilized for determining the redundant design stage and how it can be changed efficiently using the tracking algorithm. As the size of the design history increases with the number of collaborative designers and their design stages, this design history mechanism contributes to a decrease in size and captures the characteristics of design using features. As possible directions for future research this suggested framework can provide an insight into the design tendencies of designers and also be used as a reference model for intelligent CAD systems with an extracted design history-based knowledge database.     

Metropolis: an integrated electronic system design environment

Today, the design chain lacks adequate support, with most system-level designers using a collection of unlinked tools. The implementation then proceeds with informal techniques involving numerous human-language interactions that create unnecessary and unwanted iterations among groups of designers in different companies or different divisions. The move toward programmable platforms shifts the design implementation task toward embedded software design. When embedded software reaches the complexity typical of today's designs, the risk that the software will not function correctly increases exponentially. The Metropolis project seeks to develop a unified framework that can cope with this challenge. Based on a metamodel with formal semantics that developers can use to capture designs, Metropolis provides an environment for complex electronic-system design that supports simulation, formal analysis, and synthesis.     

Modeling design objects in CAD system for Service/Product Engineering

This paper proposes a new type of service CAD system utilized in Service/Product Engineering (SPE), a much-needed and novel engineering discipline within the background of servicification. In this research a design-object model was defined, and a prototype named Service Explorer was implemented. The model represents critical concepts such as value, costs, functions either of products or of service activities, and entities. Through its application to business cases such as selling washing machines, providing pay-per-wash service, and cleaning washing machines, the Service Explorer was proven to support designers as they describe and operate design objects. In the future we expect that the Service Explorer can help designers with generating new ideas.