Fang Ming-lun

Model reconstruction of existing products using neural networks for reverse engineering

In many cases, the task of manufacturing a new product starts with a prototype. Then the detailed physical characteristics of the product is extracted to facilitate its redesign or manufacture. Reverse engineering is the process by which this is done. In general, reverse engineering is accomplished through two stages-part digitizing and surface modeling. Techniques for part digitizing are well established and commercial systems are available. The area that is less developed is to generate models based on the digitized points. The paper emphasizes the applications of neural networks in reconstruction of computer models for existing surfaces. Three neural networks which use the value of defined surface parameters as input and identify the correspondent points are designed and trained using a backpropagation algorithm. In order to solve the problem of the network visual feasibility, functions of OpenGL are introduced in the training program to monitor changes of the parameters and errors of the networks. To evaluate the effectiveness of the approach, a mathematically known surface, a non uniform B spline surface is used for generating a number of samples for training the networks. The trained networks then generate a number of new points which can be used to reconstruct computer representations of the existing surfaces and to manufacture these surfaces.

Knowledge-based platform for collaborative innovation development of products

The platform of distributed design and resource sharing is important for medium-sized and small companies in developing products to improve competitiveness. As a background of creative product design, a knowledge model based on product collaborative innovation development of products (CIDP) is proposed. Characteristics of CIDP are analyzed, and the framework and key technologies of the CDDP-platform based knowledge studied. Through integration of existing system and interface designs, a development platform has been built to support the PCID within knowledge-based engineering (KBE). An example is presented, indicating that the prototype system is maneuverable and practical.

The Neural-fuzzy Modeling and Genetic Optimization in WEDM

Considering the needs for getting more precise parameters and at the same time to get faster cutting speed and better surface roughness in Wire Electrical Discharge Machining (WEDM), the authors established a model of WEDM, which has higher forecast precision and generalization ability and could help us in getting better understanding of the basic principles of WEDM. The model combined modeling function of fuzzy inference with the learning ability of artificial neural network; and a set of rules has been generated directly from the experimental data. Integrated with the genetic optimization procedure, the fuzzy inference systems are used to optimize the wire electrical discharge model of WEDM and the optimum results of the model have proved the feasibility and practicability of the system in WEDM.

Research on concurrent design of collaborative product commerce oriented discrete manufacturing enterprises

In order to fulfill the product concurrent design requirements of discrete manufacturing enterprises, this paper puts forth for the first time a Collaborative Product Commerce (CPC) oriented X2D (X to Design) theory, which can take Collaboration, Commerce and Concurrence (3C) into realization during the product design stage. At the same time, this research adopts VPN (Virtual Private Network) technique to ensure the security of product data and information during transportation. By building CPC-oriented and VPN-based framework of X2D product concurrent design system, the paper explores a way for discrete enterprises adapting to the drastically competitive market and performing their product innovation.

Reconstruction technique in reverse engineering

Creating CAD models from physical objects is a growing demand in areas from automotive subcontracting to consumer products and industrial design. We are meeting this demand with reconstruction technique, a quick and accurate solution for reverse engineering. Creating a CAD model lets you benefit from the advantages offered by CAD/CAM technology, such as the ability to rapidly and accurately visualize, analyze and modify the model, and then generate machining tool paths. With reconstruction technique, surfaces are automatically created directly from a digitized points file, even from one with millions of points. This paper addresses our research works in reverse engineering.

Design of a fuzzy pre-compensator PID tension controller for fabric based on DSP

A new control method is proposed for fabric tension regulation in an electronic let-off and take-up system designed for rapier loom. It is based on a fuzzy pre-compensator PID control strategy, which actively compensates for dynamic changes in the system and unpredictable external disturbances. The performance of scheme performed on an AC servomotor tension control has been tested under the varying load conditions. The experimental results show the effectiveness of the proposed tension controller in coping with large dynamic variations commonly seen in web tension applications.

Microstructural Comparison and Analysis of Bone Scaffold Prepared by FDM and SLS Process

Three-dimensional (3D) micro-structure of bone scaffold played an important role in cell adhesion and reproduction. The introduction of 3D measuring techniques in bone research made it possible to capture the actual architecture of bone scaffold without assumptions of the structure type. Two bone scaffolds fabricated by FDM and SLS were reconstructed and analyzed, then were compared with 3D structure indices of canine femur specimens. Based on the direct 3D analysis, there were obvious differences between two scaffolds in structural characteristics. Scaffolds prepared by FDM showed a denser and plate structure, a lower porosity, the trabecular bone was thinner. While scaffolds prepared by SLS showed a rod-shaped structure, were closer to real canine femur specimens, had a higher inter-connectivity. Scaffolds prepared by these two methods had no significant anisotropy.

DSP-Based Intelligent Tension Controller

Tension control is difficult and pivotal in lots of fields. This paper mainly discusses the design of intelligent tension controller by a novel 16-bit DSP module. DSP is designed to meet the need of control field. It can be used in some fields such as multi-lines cutting of microsystems manufacturing. Intelligent fuzzy-PID algorithm is adopted. This paper takes let-off and take-up control system of rapier loom for example and discusses how to design DSP-based intelligent tension controller. From the given experiment, test results show that the DSP-based fuzzy-PID intelligent controller has superior performance. It can be used widely to control tension in different fields

Research on product data management based on multi-agent system

PDM (product data management) is one kind of techniques based on software and database, which integrates information and process related to products. But it is not enough to perform the complication of PDM in enterprises. Then the mechanism to harmonize all kinds of information and process is needed. The paper introduces a novel approach to implement the intelligent monitor of PDM based on MAS (multi-agent system). It carries out the management of information and process by MC (monitor center). The paper first puts forward the architecture of the whole system, then defines the structure of MC and its interoperation mode.

Establishment of person and enterprise process model in product data management system

Before the implementation of product data management (PDM) system, person model and enterprise process model (EPM) must be firstly established. For the convenience of project management, all the related users must be allocated to the “Person-User-Role-Group“ net. Based on the person model and the direction of information flow, the EPM is established subsequently. The EPM consists of several release levels, in which the access controls are defined. The EPM procedure shows the blueprint of the workflow process structure. The establishment of person model and EPM in an enterprise has been instanced at the end of this paper.