International Journal of Intelligent Engineering and Systems

Number 2, 2011

9
Fault Diagnosis Based on Fuzzy C-means Algorithm of the Optimal Number of Clusters and Probabilistic Neural Network

Authors: Qing Yang, Jinggran Guo, Dongxu Zhang, Chang Liu, Renbo Xia

Abstract

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Number of views: 354

Fault diagnosis is essential for the reliable, safe, and efficient operation of the plant and for maintaining quality of the products in industrial system. This paper presents an ensemble fault diagnosis algorithm based on fuzzy c-means algorithm (FCM) with the Optimal Number of Clusters (ONC) and probabilistic neural network (PNN), called FCM-ONC-PNN. In clustering methods, the estimation of the optimal number of clusters is significant for subsequent analysis. As a simple clustering method, FCM has been widely discussed and applied in pattern recognition and machine learning, but FCM could not guarantee unique clustering result because initial cluster number is chosen randomly. As the number of clusters is randomly chosen, the iterative amount is large and the result of the classification is unstable. In this paper, firstly subtractive clustering is proposed to find the optimal number of clusters and the clustering results of the FCM are compared with random initialization method, and then PNN is used to classify the clustering data of FCM. The experiments show that the modified initial cluster number of FCM algorithm can improve the speed, and reduce the iterative amount. At the same time, FCM-ONC-PNN approach can make classification more stable and have higher precision.

10
A Satellite Networks Fault Management Method based on Cooperation

Authors: Wenbo Zhang , Xiaobo Tan

Abstract

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Number of views: 312

Different from terrestrial networks, satellite network topology is time-varying. Moreover, satellite networks communication resources are scare and expensive. So it is important to research on the fault management for satellite networks to insure it work safely and smoothly. However, the traditional fault management method for terrestrial networks is difficult to use for satellite networks. In this paper, the satellite networks topology is studied and the satellite networks management architecture is established. Based on these the three level management mechanism is proposed and put forward a new fault management method for satellite networks. When a satellite agent could respond to the network management instruction received from the management station, the traditional fault management method was used through network management technique. If the satellite could not respond to the network management demand, the intra-domain cooperation or inter-domain cooperation would be activated. The suspected fault satellite could be tested through cooperation among the satellite agents in satellites. The simulation results shows that in the circumstance of the low faulty frequency, the new method could be effectively used in satellite network with short cooperative time and low throughput.

10
A New Knowledge Modeling Method for Product Design

Authors: Lingling Li, Zhigang Li, Fenfen Zhu, Liguo Ma

Abstract

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Number of views: 353

The representation and organization of knowledge is the core of key technologies of artificial intelligence, and the modeling of design knowledge is an important and difficult step in developing intelligent designing system. The Design-Mode-Oriented Model (DMOM) used in representation of design knowledge was proposed in this paper. And corresponding to DMOM, three object design models, named as function model, parametric model and case model were also proposed to represent the knowledge of object design. The information gathered from users can be classified into three kinds and each of which represents functions, technical specifications and types of product respectively. Three design modes were also established by mapping the three kinds of information to corresponding object design models. By using model transformation, design information can be processed and the solution of design can be found. This modeling method can be used in the applications of designing for most of electrical and mechanical products.

10
Intelligent Calibration Method of low cost MEMS Inertial Measurement Unit for an FPGA-based Navigation System

Authors: Lei Wang, Fei Wang

Abstract

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Number of views: 440

Based on a small, lightweight, low-cost high performance inertial Measurement Units(IMU), an effective calibration method is implemented to evaluate the performance of Micro-Electro-Mechanical Systems(MEMS) sensors suffering from various errors to get acceptable navigation results. A prototype development board based on FPGA, dual core processor’s configuration for INS/GPS integrated navigation system is designed for experimental testing. The significant error sources of IMU such as bias, scale factor, and misalignment are estimated in virtue of static tests, rate tests, and thermal tests. Moreover, an effective intelligent calibration method combining with Kalman filter is proposed to estimate parameters and reduce the effect of IMU dynamic errors that can degrade the system performance. The efficiency of proposed approach is demonstrated by various experimental scenarios.

11
An Methodology for Dimension Parameter transfer to Support Variant Product

Authors: Weiping Shao , Yongping Hao, Pengfei Zeng, Chunyan Wang

Abstract

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Number of views: 316

In variant design of mass customization, sometimes it’s necessary to modify some dimensions of product modules. This paper introduces a methodology for dimension parameter transfer related to variant design that based on constraint satisfaction priority of part and assembly connection. In order to research parameter transfer path and build the parameter transfer structure, parts and its variant parameters are classified. Parameter association relations between parts are analyzed based on assembly connection in product. Parameter constraint relations also presented for variant design. And, parameter transfer structure and model is put forward. Constraint forms between dimension parameter are listed and described, and then a reconstructed network structure for dimension constraints relations is built in which every edge has only one direction with purpose of making the network simple and easy to solve the constraints. Finally, using Pro-E as a 3D environment and VC++ as a development tool, all methods are applied to a shaft-hub link of speed reducer product, thus verifying the proposed method.