Customized Encryption of Computer Aided Design Models for Collaboration in Cloud Manufacturing Environment

Author(s):  
Xiantao Cai ◽  
Weidong Li ◽  
Fazhi He ◽  
Xiaoxia Li

Computer aided design (CAD) models reflect design goals, intentions, and functions so that they are the key intellectual properties of companies. In a Cloud manufacturing environment, how to effectively protect the sensitive feature information for a model owner while enabling the owner to flexibly share the rest of the CAD model with collaborators is an important yet challenging research issue. In this paper, an innovative partial encryption approach, which is able to represent a CAD model into the granularity of sharing information in order to address various collaboration scenarios and customized requirements from the model owner and collaborators, is presented. The approach is composed of a customized encryption algorithm for a CAD model, a key based customized authorization algorithm for collaborators to decrypt shared features in the model, and a customized geometric transformation method to support the effective protection model-based visualization of the model for collaboration. With this approach, a CAD model can be flexibly encrypted to realize partial sharing of features and safe protection of the rest of the model according to collaboration requirements. Meanwhile, during encryption and decryption, the CAD model is always manifold no matter which feature is encrypted or decrypted to ensure user friendliness, model validity, and robustness of the approach. A case study is used to verify and illustrate the effectiveness of the approach. This research is a new attempt to design a content-based and customized encryption approach applicable to CAD model-based collaboration in a Cloud manufacturing environment.

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.


3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi

Laser additive manufacturing is an advanced manufacturing process for making prototypes as well as functional parts directly from the three dimensional (3D) Computer-Aided Design (CAD) model of the part and the parts are built up adding materials layer after layer, until the part is competed. Of all the additive manufacturing process, laser additive manufacturing is more favoured because of the advantages that laser offers. Laser is characterized by collimated linear beam that can be accurately controlled. This chapter brings to light, the various laser additive manufacturing technologies such as: - selective laser sintering and melting, stereolithography and laser metal deposition. Each of these laser additive manufacturing technologies are described with their merits and demerits as well as their areas of applications. Properties of some of the parts produced through these processes are also reviewed in this chapter.


2020 ◽  
Vol 36 ◽  
pp. 101554
Author(s):  
Wenjin Li ◽  
Gary Mac ◽  
Nektarios Georgios Tsoutsos ◽  
Nikhil Gupta ◽  
Ramesh Karri

2005 ◽  
Vol 5 (4) ◽  
pp. 381-387 ◽  
Author(s):  
Zahed Siddique ◽  
Karunakar Boddu

In order to provide products that can be tailored to the need of the customer, it is necessary to integrate the customer into the design process. In this paper we present a mass customization computer-aided design (CAD) framework that helps to integrate the customer into the design of user-configurable products. A template approach, which considers both modularity and scaling, is utilized to concisely represent a CAD model of the entire family. The system accepts user selections and parameters to automatically create a CAD model of the customized product in real time and then shows the model to the user. The system is implemented using PRO/ENGINEER and demonstrated through customization of bicycle frames.


Author(s):  
Ali Aidibe ◽  
Souheil-Antoine Tahan

At the end of the manufacturing process, engineers need to know if a manufactured part fits its computer-aided design (CAD) model and how is the amplitude of inherent variation of manufacturing process. Non-rigid parts, at free state condition, may have a significant different form than their CAD model due to gravity loads; residual stresses induced distortion and/or assembly load. Today, a complicated and expensive specialized fixture is needed to conform these parts. To tackle the above challenges, we present in this paper a new approach for metrology of fixtureless non-rigid parts. This approach combines the curvature properties of manufactured parts with the extreme value statistic test as identification method to distinguish profile deviation due to the manufacturing process from part’s deformation due to the flexibility of the part and to determine whether the tolerance fits the CAD model or no. This approach is tested on simulated typical industrial sheet metal giving satisfying results in terms of percentage of errors in defect area and in peak profile deviation estimated.


Author(s):  
Harley R. Myler ◽  
Avelino J. Gonzalez ◽  
Massood Towhidnejad

A number of automated reasoning systems find their basis in process control engineering. These programs are often model-based and use individual frames to represent component functionality. This representation scheme allows the process system to be dynamically monitored and controlled as the reasoning system need only simulate the behavior of the modeled system while comparing its behavior to real-time data. The knowledge acquisition task required for the construction of knowledge bases for these systems is formidable because of the necessity of accurately modeling hundreds of physical devices. We discuss a novel approach to the capture of this component knowledge entitled automated knowledge generation (AKG) that utilizes constraint mechanisms predicated on physical behavior of devices for the propagation of truth through the component model base. A basic objective has been to construct a complete knowledge base for a model-based reasoning system from information that resides in computer-aided design (CAD) databases. If CAD has been used in the design of a process control system, then structural information relating the components will be available and can be utilized for the knowledge acquisition function. Relaxation labeling is the constraint-satisfaction method used to resolve the functionality of the network of components. It is shown that the relaxation algorithm used is superior to simple translation schemes.


Author(s):  
Ming C. Leu ◽  
Amit Gawate

Implant based dental restorations have many advantages over standard removable dentures because using implants can prevent the loss of jawbones, help restore facial features, and enable the patients to get firm bites. A critical step in this kind of restorations is the fabrication of the dental bar on which the denture sits. A dental bar is patient-specific because each patient’s jawbone is unique and the device needs to be conforming to the patient’s gingival surface. The design of a dental bar is crucial to the success of dental restorations. Traditionally, designing a dental bar is a lengthy and laborious process and requires high levels of craftsmanship. There have been attempts to develop CAD/CAM systems towards automating design and fabrication of dental restorations. However, currently available commercial CAD/CAM systems are only capable of making crowns, bridges, copings, onlays and veneers, and they are not capable of making dental restorations involving multiple teeth. The present paper describes a method for computer aided design of a dental bar used in implant based dental restorations. The method starts with a set of digital scan data representing the patient’s gingival surface and generates a CAD model of a dental bar that is ready for fabrication of a physical dental bar.


Author(s):  
Olalere Folasayo Enoch ◽  
Ab Aziz Bin Shuaib ◽  
Ramli bin Ismail

This paper investigates the knowledge regarding how user-centre design can be built in ceramic consumer products. The paper gives the general overview of ceramics, computer-aided design and its application in ceramic product development. It also illuminates on product emotion, its influence on consumers’ behaviour and how it can be integrated into new product conceptualization. Furthermore, the paper analysed the systematic approach in building user-centred design in new product and also reveals how CAD can be used to achieve a user-centred design. In order to test the viability of CAD in achieving user-centred design, a study was performed where a CAD-model of a multi-functional ceramic pot was created and a questionnaire with the image (CAD model) and eight emotions was given to participants so as to know their emotional responses toward the product. The result from the study reveals the viability of computer aided design as tool for building user-centred design in consumer ceramics’ product development.


Author(s):  
Yuchu Qin ◽  
Wenlong Lu ◽  
Qunfen Qi ◽  
Xiaojun Liu ◽  
Yanru Zhong ◽  
...  

Exchanging computer-aided design (CAD) model data among heterogeneous CAD systems is indispensable for collaborative product development. Currently, the industry mainly uses the standardized neutral files-based methods to implement such exchange. While at the same time, the application of web ontology language (OWL) file and underlying semantic web technologies in CAD model data exchange is gaining importance and popularity within the academia. The coexistence of different types of methods has generated a series of controversies and questions within the industry and the academia. Yet, can the neutral files-based exchange methods completely implement model data exchange among heterogeneous CAD systems? What challenges have been addressed to date by the developed CAD model data exchange standards? Why OWL has been introduced to CAD model data exchange? Does CAD model data exchange really need OWL? Are there any issues in existing neutral files-based exchange methods and OWL file-based exchange methods need to be addressed in future studies? This paper proposes to conduct a study of the standardized neutral files-based exchange methods and OWL file-based exchange methods. An in-depth analysis of the widely used standard for the exchange of product model data (STEP) method and the newly emerging OWL methods is first provided. Then, the paper makes a detailed comparison between these two types of methods based on this analysis. Finally, some issues in the two types of methods that need to be addressed in the future are discussed.


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