Internet-Enabled Collaborative Fixture Design ^†

Abstract

The design of fixtures is a complex and instinctive process. A proficient fixture design system customized for particular applications reduces manufacturing costs and lead times. Various computer-aided systems are available to assist in the many manufacturing stages in today’s industry. A fixture design system should facilitate the seamless movement of information among several domains to enhance product design and production processes. The fixture design system should be easily transferable and compatible with many operating platforms. This study discusses creating an Internet-enabled interactive fixture design system that enables seamless communication among different disciplines in product development. Utilizing the Internet and Virtual Reality Modelling Language (VRML) allows for the exchange of information and expertise among computer-aided manufacturing systems. The CAD model of fixturing pieces is first turned into VRML coding. The VRML code for the model can be modified to vary the size and dimensions of the CAD model, facilitating alterations such as scaling fixture components, repositioning mounting points, and resizing clamping parts to align with specific design needs. The VRML model of the fixturing system was created with Java and built on an FTTP server architecture. It guarantees that the system performs consistently across different platforms. This work has also established a mechanism for comprehensive fixture design independent of a locating scheme. Establishing a library for storing previous fixture designs can prevent the need to recreate the current model.

1. Introduction

Modern customers expect more personalized products, which necessitates reduced product development timelines. New manufacturing concepts have been adopted to address this demand, including computer-integrated production, lean manufacturing, flexible manufacturing systems, agile manufacturing, and Internet-based manufacturing. Internet-enabled collaborative fixture manufacturing aims to address issues with different software solutions and provide a cohesive manufacturing setting. The several computer-aided systems utilized in the manufacturing process need to be able to collaborate smoothly to achieve this purpose. The current work presents a step toward accomplishing this objective by developing a fixture design system capable of being connected to the Internet. Fixtures are tools designed to hold workpieces in a stable manner and to align themselves consistently with the tools as they are being cut. Therefore, they are necessary to guarantee that a machined item has the degree of required geometric precision. Base plates, spacers, locators, stop elements, and clamps are standard components used in modular fixtures. These components are pre-manufactured and reusable, and they are used in a variety of installations. It is possible to build the modular fixture in such a way that they may handle workpieces of varying sizes and forms, providing design flexibility and reusing ability.

Fan et al. [1] created a collaborative fixture design system employing service-oriented architecture. Mervyn et al. [2] developed a fixture design information system to assist integrated design and manufacture. Rex et al. [3] introduced a versatile fixture design methodology to reduce workpiece distortion during milling operations. Mervyn et al. [4] created an Internet-supported fixture design platform. Duan et al. [5] presented the utilization of XML in graphic interchange technology for flexible fixtures, emphasizing the prospects for standardized data format and exchange in production settings. Li et al. [6] introduced a web-based system for optimizing process planning, highlighting the efficiency improvements attainable via centralized online platforms. Kang et al. [7] proposed fixture assembly planning within web-based collaborative environments, demonstrating the benefits of real-time collaboration and data sharing. Zuo et al. [8] developed a framework for energy consumption evaluation and analysis utilizing IoT devices and cloud-based analytics. Kim et al. [9] focused on retrieving CAD model data over web-based platforms, enabling interactive product creation in dispersed settings. Balakrishna et al. [10] investigated integrating CAD/CAM/CAE systems using STEP/XML formats, emphasizing interoperability and data exchange among various design and analysis tools. Rex et al. [11] developed a simultaneous technique for selecting the optimum fixture layout and clamping force. Song et al. [12] developed a digital mock-up system for complicated CAD assembly. Wang et al. [13] established a CAD/CAM combined system in a collaborative development framework. Jarzabek et al. [14] introduced an XML-based approach and tool for managing variant requirements in domain models. Rex et al. [15] devised a comprehensive fixture layout design methodology, employing finite element analysis and artificial neural networks.

The present study uses VRML for the fixture design system because it can depict 3D objects in a web-based context while ensuring simplicity and extensive interoperability across many platforms. Despite the enhanced capabilities of newer technologies such as WebGL and Unity, VRML was chosen for its reduced computing demands and seamless interaction with current CAD models and web architectures [16,17,18]. This decision prioritized interoperability, ease of implementation, and uniform performance across many systems and networks. Further, the proposed approach introduces several key improvements over traditional fixture design systems. Unlike systems that work in isolation, it uses the Internet to enable real-time collaboration, allowing for better communication between stakeholders. By combining VRML with Java SE23 and Java 3D v1.5.2, the system offers advanced 3D visualization and interaction, making fixture design more dynamic. The system also provides a flexible design mechanism that works independently of specific locating schemes, making it more versatile. A library for storing previous fixture designs speeds up the process by allowing the reuse of models. Additionally, the system features better processing speed, lower memory use, and the ability to handle complex designs, offering significant performance advantages over older systems.

The format of the paper is as follows: The framework of the system is described in Section 2, and the VRML schemas are presented in Section 3. Section 4 presents the primary interactive fixture design process, while Section 5 provides the paper’s conclusion.

2. Framework for the System

The system utilizes Java for programming, Java 3D for graphics API, and VRML for information exchange file format to ensure interoperability across different operating platforms. The system’s architecture, as seen in Figure 1, is called an FTTP Server architecture. This architecture divides programme execution into client and server. Clients handle user input and 3D model display. The server processes modelling and the repository stores fixture element data.

2.1. The FTTPServer

Para-solid’s WRL format stores the files of durable model parts, including workpieces and fixture elements. The capability of the system depends on the ability to derive data from it. Polygonization of the model is carried out by the Para-solid modelling kernel deployed on the server. This kernel also delivers the WRL file. A class must be present to make function calls to the Para-solid modelling kernel developed in a native language, a Java native interface (JNI), and to make function calls to the Para-solid modelling kernel developed in a native language. The server class polygonises the model and saves the facet information as a facet data (FD) VRML file on the FTTP server whenever a client requests a workpiece or fixture element. This enables the client to access the information. Additionally, the VRML file contains all the data required for client-side visualization.

2.2. Client Framework

Client-side components include a menu class, viewer class, and interactive fixture design (IFD) module. The customer starts the software by creating the GUI and Java 3D canvas for modelling and fixture design with the menu class. Every constructive solid geometry (CSG) modelling system capability is available in the stable modelling interface. Primitive stable functions (block, sphere, cylinder, and prism), Boolean operations (union, subtraction, and intersection), and transformation operations are mentioned. A server function call is made using Java Remote Method Invocation (RMI) when a modelling or object choice is selected from the menu. The Java 3D canvas displays the model design managed by the viewer class. Calls to parse VRML files on the FTTP server send data to Java 3D classes for canvas drawing. The fundamental IFD technique, fixture component query class, fixture design blueprint class, fixture design information parser, and numerous fixture rule algorithms make up the IFD module.

2.3. Repository Module

The Apache FTP server and the fixture element database are within the repository. On the Apache FTP server, the WRL files are kept for safekeeping. A MySQL 8.3 LTS relational database server was utilized to establish the fixture element database. The fixture element query class can perform complicated queries through Java database connectivity (JDBC) by utilizing the MySQL database management system. This is advantageous for introducing more rules into the system. Base plates, support pins, locating cylinders, stops, clamps, and risers are some of the different fixture pieces included in the database. The database server makes it possible for multiple personnel associated with fixture elements to access and monitor the status of their inventory.

2.4. System Application Module

Regardless of location, the part designer can design a part and then put it on the server. The process planner is responsible for creating the procedure and sending the data to the repository as VRML files. As a result of the fixture design client providing the fixture designer with access to the information regarding the part and the process plan, the fixture designer can develop the fixture from any location. Afterwards, the information on the fixture design is saved in the repository as a VRML file about the fixture design. By retrieving the necessary VRML file for the fixture design of the workpiece, the process planner can access the fixture design in the client environment. It is also possible for the fixture designer to change the inventory state of the products stored in the database. Through the online interface, the procurement planners can keep track of the current inventory status of the fixture pieces.

3. VRML Schema in Fixture Design

The WRL file is used for visualization purposes, and it contains information about the many aspects of the polygonized model of workpieces and fixture elements. Figure 2 illustrates the VRML plugin layout displayed by the system. Before describing data using VRML, a document type (DTD) description must first be specified. As a result, the data structure included within the VRML file can be regulated. There is a hierarchical structure to which XML tags all adhere. The root tag is consistently identified as <DOCUMENT> regarding VRML files. Within the WRL schema, every individual identified by a <BODYTAG> is further segmented into numerous faces. The <FACETAG> is employed to identify the various surfaces of the human body. The feature known as <FACETYPE> provides information regarding the shape of the face, including cylindrical, planar, or spherical characteristics. The corners of every face are represented by the icon <SNAPPOINT>. Facets, defined as elemental triangles, further subdivide each cup. Every triangle’s vertices are represented by their coordinates, which are included in the <FACET> tag.

The VRML file is necessary to create a collaborative environment for fixture design. The component, the base plate, the supporting areas, the positioning surfaces, the components, the clamp contact area, and the characteristics are all included in this graphical representation. Information about fixture analysis modules is also included in the VRML file assigned to the fixture design.

4. Interactive Approach for Fixture Design

This section presents a developed methodology for fixture design that is adaptable and independent of locating schemes, allowing the comprehensive design of complex parts. The flexibility in the locating scheme is achieved through a modular fixture design that does not depend on specific locating points, allowing the system to adapt to different parts and configurations without significant redesigns. The design ensures accuracy and repeatability across various applications using adjustable components and a systematic approach to fixture assembly. The collaborative system methodology is characterized by sequential interactivity. The process is depicted in Figure 3.

Integrating VRML with Java and Java 3D establishes a formidable foundation for developing interactive 3D applications; comprehending its performance parameters, including processing speed, memory needs, load handling capacities, and startup durations, is crucial. The memory footprint for Java 3D applications varies, with basic programmes necessitating approximately 25 MB, whereas more intricate sceneries may surpass 100 MB. Inadequate RAM may result in performance constraints caused by paging. Java 3D is engineered to accommodate diverse hardware, ranging from economical graphics cards to high-performance workstations, utilizing optimized rendering pathways and scene graph management methodologies, including OpenGL for enhanced rendering, to manage varying loads and facilitate more intricate virtual environments. Startup durations generally range from 3 s for simple loading to 14 s for intricate 3D multimedia, minimizing customer irritation. Moreover, Java 3D utilizes optimization strategies such as scene graph compilation, capability bits, and unordered rendering to save rendering overhead and enhance efficiency.

5. Result and Discussion

The model files were initially built using SolidWorks 2023. The solid model files are not easily converted or suitable for other mediums. They need to be transformed into another widely used portable language. This language must be modifiable. The model file was transformed into a VRML file format. This format was be utilized to create the 3D models. VRML has a unique syntax for creating shapes, allowing us to accurately design the desired shape and dimensions.

The Virtual Reality Modelling Language (VRML) file format describes interactive 3-dimensional vector graphics generated for the web. VRML files contain text files that define 3D polygon vertices and edges. Surface colour, UV-mapped textures, shininess, and transparency are included. URLs can link to graphical objects, allowing web browsers to obtain webpages or VRML files from the Internet. User inputs and timings can activate virtual world animations, audio, illumination, and more. A special Script Node lets VRML files contain programme code. VRML “worlds” have the ‘wrl’ extension. Multiple 3D modelling software can export VRML objects and scenarios. Figure 4 illustrates the fixture design VRML code.

VRML files require a plugin for viewing on all workstations, as not all websites and browsers can interpret these codes. The plugins provide the connection between VRML and browsers and systems. This plugin reads data from VRML files. A VRML display system utilizing virtual reality technology enables browsing and access via the Internet. Programming modelling can be utilised with the VRML, and modelling with visual modelling toolkit software. The modelling of the real estate community environment’s shape, physics, behaviour, and related objects has been finished. Figure 4 displays the operational arrangement of the VRML plugin. Figure 5 shows the representation of a fixture element in a web browser through plugins.

The created system supports collaborative fixture design production, as shown in Figure 6. Product designers can save parts on the server from anywhere. After developing a process plan, the process planner uploads the required XML data to the repository. The repository provides part data and the process strategy for remote fixture design. The repository stores fixture design data as an XML file. The process planner can locate and analyze this fixture design in their client system’s XML file. By updating fixture element inventory status in the database, fixture designers can let procurement planners track inventory via the web. This study shows the system’s Internet-based fixture design efficiency. The proposed system was evaluated using modular fixture components commonly utilized in manufacturing processes, as illustrated in Figure 5. This initial evaluation was limited to a select number of modular components.

Optimizing server response times and data synchronization can help address a key obstacle in client–server interactions that disrupt real-time collaboration. VRML’s limitations in handling complex designs may lead to performance issues; however, simplifying models or using WebGL can help resolve these problems. Ensuring interoperability across browsers and devices is also crucial, requiring a responsive design to improve accessibility. Addressing these challenges will make the fixture design system more robust, user-friendly, and effective in industrial environments.

6. Conclusions

A comprehensive, collaborative system enabled by the Internet and capable of carrying out 3D fixture designs was developed as part of the current study. Using Java and Java 3D, the system can be adaptable and compatible across various operating systems. It is possible to decouple fixture design systems from standard CAD systems with the assistance of the VRML file developed for fixture design. This file is helpful in the process of establishing an integrated manufacturing environment that is centred on the Internet for fixture design. In addition, plugins were utilized to display the fixture system in a web-based environment to promote collaborative device creation. Future work will involve implementing and testing the system in real-world manufacturing environments. Further, an attempt will be made to explore the integration of cloud computing to facilitate real-time collaboration among stakeholders and improve scalability. Integrating sophisticated virtual reality interfaces could enhance user interaction and visualization by offering immersive design experiences.