Co-CAD: A Collaborative Mechanical CAD System

1994 ◽  
Vol 3 (4) ◽  
pp. 341-350 ◽  
Author(s):  
Mark A. Gisi ◽  
Cristiano Sacchi

It is becoming increasingly common for manufacturing design teams to be composed of members belonging to the same organization, yet located in geographically different places. This has significantly increased the need for better support of synchronous communication among team members collaborating over a design. Unfortunately, there is a considerable technological gap in the support for collaborative, synchronously communicating mechanical CAD systems. In this paper we describe a prototype system, CoCAD, that provides a number of features that support synchronous collaboration among a number of mechanical CAD engineers located at different sites. Some of these features include the ability for each person to edit a design, the ability for each user to customize their local view of a design, the ability for each user to share a common view of a design, a shared pointer, the ability for someone to join in the middle of a design session, and object ownership and access permissions.

Author(s):  
Zhiyong Huang ◽  
Fazhi He ◽  
Xiantao Cai ◽  
Xiaoxia Li ◽  
Yuan Cheng

Undo/redo mechanism is an important issue in interaction-centered CAD system. Since the design task is a creative process, the users of CAD systems have to use undo/redo mechanism to repeatly modify the CAD model in order to achieve a satisfied result. However, undo/redo mechanism is not an easy work even in standalone CAD systems. This is the reason why different commercial CAD systems are equipped with different level of undo/redo mechanism. Therefore, group undo/redo mechanism in collaborative system becomes a special challenge. This paper proposed a group undo/redo method in replicated collaborative modeling system. In our method, one user’s operation intention can be preserved in both local site and remote sites. The preservation is based on dependency relationship among users at different sites. The implementation of the Undo/Redo operation in both local site and remote site is described in detail respectively. The proposed approach has been tested in a prototype system with case study. The authors believe that this work represents the first attempt to address group undo/redo mechanism in collaborative CAD systems.


Author(s):  
J Y H Fuh ◽  
S H Wu ◽  
K S Lee

The die casting industry has an imperative need for an automated or semi-automated approach for die casting die design. One of the key challenges that die makers face is how to shorten the lead-time to the market and reduce the cost in die design and manufacturing. Most die makers have employed computer aided design (CAD) systems to improve the efficiency and quality of die design. However, conventional CAD systems do not have the functionality specially for the die casting die design, therefore, a specific computer aided system for die casting die design is needed to meet the market demand. This paper describes a prototype system structured by several functional modules as specific add-on applications on a commercial CAD system for die casting die design. These modules include data initialization, cavity layout, gating system design, die-base, parting, standard component design, etc. Focus of the development will be placed on gating, runner and die-base design.


Author(s):  
V. A. Martynyuk ◽  
V. A. Trudonoshin ◽  
V. G. Fedoruk

The article considers applications of foreign CAD-systems in creating the challenging projects at domestic enterprises and design bureaus. As stated in the article "... presently, there is no domestic CAD-system that could completely replace such foreign products as NX, CATIA, Credo". Besides, due to international cooperation in creating the challenging projects (for example, the project to create a modern wide-body aircraft, proposed jointly with China), it makes sense to use the worldwide known and popular CAD systems (the aforementioned NX, CATIA, Credo). Therefore, in the foreseeable future, we will still have to use foreign software products. Of course, there always remains a question of the reliability of the results obtained. Actually, this question is always open regardless of what software product is used - domestic or foreign. This question has been haunting both developers and users of CAD systems for the last 30 to 40 years. But with using domestic systems, it is much easier to identify the cause of inaccurate results and correct the mathematical models used, the methods of numerical integration applied, and the solution of systems of nonlinear algebraic systems. Everything is much more complicated if we use a foreign software product. All advertising conversations that there is a tool to make the detected errors available to the developers, remain only conversations in the real world. It is easily understandable to domestic users, and, especially, to domestic developers of similar software products. The existing development rates and competition for potential buyers dictate a rigid framework of deadlines for releasing all new versions of the product and introducing the latest developments into commercial product, etc. As a result, the known errors migrate from version to version, and many users have accepted it long ago. Especially, this concerns the less popular tools rather than the most popular applications (modules) of a CAD system. For example, in CAD systems, the "Modeling" module where geometric models of designed parts and assembly units are created has been repeatedly crosschecked. But most of the errors are hidden in applications related to the design of parts from sheet material and to the pipeline design, as well as in applications related to the analysis of moving mechanisms and to the strength or gas dynamic analysis by the finite element method.The article gives a concrete example of a moving mechanism in the analysis of which an error was detected using the mathematical model of external influence (a source of speed) in the NX 10.0 system of Siemens.


2021 ◽  
Vol 1 ◽  
pp. 1529-1536
Author(s):  
Mohammad Reza Dastmalchi ◽  
Bimal Balakrishnan ◽  
Danielle Oprean

AbstractTeam collaboration is a critical necessity of the modern-day engineering design profession. This is no surprise given that teams typically possess more task-relevant skills and knowledge than individuals (Levine & Choi, 2004). Advancements in digital media provide new opportunities for collaboration across the design lifecycle. However, early stages of the design process still pose challenges to digitally mediated design collaboration due to greater representational abstraction and the presence of multiple modalities for design ideation. Usually, design teams spend a substantial amount of time generating a broad set of ideas that can lead them to a wide range of design solutions during the ideation phase. However, sooner or later, teams should narrow down their vision for a final solution. What factors influence team members to eliminate or select an idea? Our study is an attempt to demonstrate some examples of this challenge. By drawing on research in team cognition, particularly the concept of transactive memory system (TMS) we studied a design teams' communication and media use during the ideation phase. The goal was to see if media type and communication modes can predict a team's decisions on selecting and eliminating ideas.


Author(s):  
S. Minami ◽  
T. Ishida ◽  
S. Yamamoto ◽  
K. Tomita ◽  
M. Odamura

Abstract A concept for the initial stage of the mechanical design and its implementation in the computer-aided design (CAD) are presented. The process of decision making in design is: (1) determining an outline of the whole assembly using a 2-dimensional model that is easy to operate; (2) checking the outline using a 3-dimensional model in which it is easy to identify the spatial relationships; (3) determining details of its sub-assemblies or their components using the 2-dimensional model; and (4) checking the details using the 3-dimensional model. The CAD system must provide consistent relationships through all the steps. For that, following functions are implemented in our prototype system: (1) a 2D and 3D integrated model for consistency between 2- and 3-dimensional shapes, (2) a hierarchical assembly model with dimensional constraints for consistency within an assembly and their components, and (3) a check on constraints for consistency between shapes and designers’ intentions. As a result, the system can provide an environment well fitted to the designers’ decision making process.


Author(s):  
Meisha Rosenberg ◽  
Judy M. Vance

Successful collaborative design requires in-depth communication between experts from different disciplines. Many design decisions are made based on a shared mental model and understanding of key features and functions before the first prototype is built. Large-Scale Immersive Computing Environments (LSICEs) provide the opportunity for teams of experts to view and interact with 3D CAD models using natural human motions to explore potential design configurations. This paper presents the results of a class exercise where student design teams used an LSICE to examine their design ideas and make decisions during the design process. The goal of this research is to gain an understanding of (1) whether the decisions made by the students are improved by full-scale visualizations of their designs in LSICEs, (2) how the use of LSICEs affect the communication of students with collaborators and clients, and (3) how the interaction methods provided in LSICEs affect the design process. The results of this research indicate that the use of LSICEs improves communication among design team members.


2021 ◽  
Vol 22 (18) ◽  
pp. 9697
Author(s):  
Huizhong Liu ◽  
Yu Zhang ◽  
Yingsi Wang ◽  
Xiaobao Xie ◽  
Qingshan Shi

Heavy metal pollution is widespread and persistent, and causes serious harm to the environment. Pseudomonas putida, a representative environmental microorganism, has strong resistance to heavy metals due to its multiple efflux systems. Although the functions of many efflux systems have been well-studied, the relationship between them remains unclear. Here, the relationship between the Czc and Cad systems that are predominantly responsible for cadmium efflux in P. putida KT2440 is identified. The results demonstrated that CzcR3, the response regulator of two-component system CzcRS3 in the Czc system, activates the expression of efflux pump genes czcCBA1 and czcCBA2 by directly binding to their promoters, thereby helping the strain resist cadmium stress. CzcR3 can also bind to its own promoter, but it has only a weak regulatory effect. The high-level expression of czcRS3 needs to be induced by Cd2+, and this relies on the regulation of CadR, a key regulator in the Cad system, which showed affinity to czcRS3 promoter. Our study indicates that the Cad system is involved in the regulation of the Czc system, and this relationship is important for maintaining the considerable resistance to cadmium in P. putida.


2021 ◽  
Vol 21 (S1) ◽  
Author(s):  
Giacomo Donato Cascarano ◽  
Francesco Saverio Debitonto ◽  
Ruggero Lemma ◽  
Antonio Brunetti ◽  
Domenico Buongiorno ◽  
...  

Abstract Background Computer-aided diagnosis (CAD) systems based on medical images could support physicians in the decision-making process. During the last decades, researchers have proposed CAD systems in several medical domains achieving promising results. CAD systems play an important role in digital pathology supporting pathologists in analyzing biopsy slides by means of standardized and objective workflows. In the proposed work, we designed and tested a novel CAD system module based on image processing techniques and machine learning, whose objective was to classify the condition affecting renal corpuscles (glomeruli) between sclerotic and non-sclerotic. Such discrimination is useful for the biopsy slides evaluation performed by pathologists. Results We collected 26 digital slides taken from the kidneys of 19 donors with Periodic Acid-Schiff staining. Expert pathologists have conducted the slides preparation, digital acquisition and glomeruli annotations. Before setting the classifiers, we evaluated several feature extraction techniques from the annotated regions. Then, a feature reduction procedure followed by a shallow artificial neural network allowed discriminating between the glomeruli classes. We evaluated the workflow considering an independent dataset (i.e., processing images not used in the training procedure). Ten independent runs of the training algorithm, and evaluation, allowed achieving MCC and Accuracy of 0.95 (± 0.01) and 0.99 (standard deviation < 0.00), respectively. We also obtained good precision (0.9844 ± 0.0111) and recall (0.9310 ± 0.0153). Conclusions Results on the test set confirm that the proposed workflow is consistent and reliable for the investigated domain, and it can support the clinical practice of discriminating the two classes of glomeruli. Analyses on misclassifications show that the involved images are usually affected by staining artefacts or present partial sections due to slice preparation and staining processes. In clinical practice, however, pathologists discard images showing such artefacts.


2021 ◽  
Author(s):  
Vivek Rao ◽  
Ananya Krishnan ◽  
Jieun Kwon ◽  
Euiyoung Kim ◽  
Alice Agogino ◽  
...  

Abstract Design team decision-making underpins all activities in the design process. Simultaneously, goal alignment within design teams has been shown to be essential to the success of team activities, including engineering design. However, the relationship between goal alignment and design team decision-making remains unclear. In this exploratory work, we analyze six student design teams’ decision-making strategies underlying 90 selections of design methods over the course of a human-centered design project. We simultaneously examine how well each design team’s goals are aligned in terms of their perception of shared goals and their awareness of team members’ personal goals at the midpoint and end of the design process, along with three other factors underpinning team alignment at the midpoint. We report three preliminary findings about how team goal alignment and goal awareness influence team decision-making strategy that, while lacking consistent significance, invite further research. First, we observe that a decrease in awareness of team members’ personal goals may lead student teams to use a different distribution of decision-making strategies in design than teams whose awareness stays constant or increases. Second, we find that student teams exhibiting lower overall goal alignment scores appear to more frequently use agent-driven decision-making strategies, while student teams with higher overall goal alignment scores appear to more frequently use process-driven decision-making strategies. Third, we find that while student team alignment appears to influence agent- and process-driven strategy selection, its effect on outcome-driven selection is less conclusive. While grounded in student data, these findings provide a starting place for further inquiry into of designerly behavior at the nexus of teaming and design decision-making.


Author(s):  
Tushar H. Dani ◽  
Rajit Gadh

Abstract Despite advances in Computer-Aided Design (CAD) and the evolution of the graphical user interfaces, rapid creation, editing and visualization of three-dimensional (3D) shapes remains a tedious task. Though the availability of Virtual Reality (VR)-based systems allows enhanced three-dimensional interaction and visualization, the use of VR for ab initio shape design, as opposed to ‘importing’ models from existing CAD systems, is a relatively new area of research. Of interest are computer-human interaction issues and the design and geometric tools for shape modeling in a Virtual Environment (VE). The focus of this paper is on the latter i.e. in defining the geometric tools required for a VR-CAD system and in describing a framework that meets those requirements. This framework, the Virtual Design Software Framework (VDSF) consists of the interaction and design tools, and an underlying geometric engine that provides the representation and algorithms required by these tools. The geometric engine called the Virtual Modeler uses a graph-based representation (Shape-Graph) for modeling the shapes created by the user. The Shape-Graph facilitates interactive editing by localizing the effect of editing operations and in addition provides constraint-based design and editing mechanisms that are useful in a 3D interactive virtual environment. The paper concludes with a description of the prototype system, called the Virtual Design Studio (VDS), that is currently being implemented.1.


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