Zhou Zude

Resources publication and discovery in manufacturing grid

In the manufacturing grid’s architecture, Resources Management System (RMS) is the central component responsible for disseminating resource information across the grid, accepting requests for resources, discovering and scheduling the suitable resources that match the requests for the global grid resource, and executing the requests on scheduled resources. In order to resolve the problem of resources publication and discovery in Manufacturing Grid (MGrid), the classification of manufacturing resources is first researched after which the resources encapsulation class modes are put forward. Then, a scalable two-level resource management architecture is constructed on the model, which includes root nodes, domain nodes and leaf nodes. And then an RMS is proposed, and the resources publication and discovery mechanism are detailedly described. At last, an application prototype is developed to show the validity and the practicability of the proved theory and method.

Modelling and application of optimal-selection evaluation for manufacturing grid resource

Manufacturing grid (MGrid) is a new resource sharing platform. To reduce the decision-making time of selecting appropriate resources for special clients and to improve the quality of service (QoS) in MGrid, the evaluation indices library is established, which includes the general evaluation indices, the special evaluation indices and the individual evaluation indices. The notion of agent-based resource optimal selection evaluation is proposed in the MGrid and the architecture model and the particular algorithm are presented. The experimental results show that the model and the algorithm are feasible and effective for solving the problem of resource optimal selection in the MGrid system.

Measurement error of surface-mounted fiber Bragg grating temperature sensor.

Fiber Bragg grating (FBG) sensors are extensively used to measure surface temperatures. However, the temperature gradient effect of a surface-mounted FBG sensor is often overlooked. A surface-type temperature standard setup was prepared in this study to investigate the measurement errors of FBG temperature sensors. Experimental results show that the measurement error of a bare fiber sensor has an obvious linear relationship with surface temperature, with the largest error achieved at 8.1 °C. Sensors packaged with heat conduction grease generate smaller measurement errors than do bare FBG sensors and commercial thermal resistors. Thus, high-quality packaged methods and proper modes of fixation can effectively improve the accuracy of FBG sensors in measuring surface temperatures.

Multi-agent Architecture for Collaborative CAD System

In order to improve the features of traditional CAD system, a system architecture based on multi-agent is put forward. The proposed system framework includes three levels, supporting the collaborative product design for different remote users. The user agents are classified as real-time monitoring agent, conflict detection agent, conflict solution agent, user communication agent and knowledge management agent. We give the detail flow architecture of the user agents. The experiment system presents the efficient cooperation among multidisciplinary designers.

Compensation Scheme of Position Angle Errors of Permanent-Magnet Linear Motors

The position angle is very important in the current control of permanent-magnet linear motors (PMLMs), and its error affects the control precision of currents. However, the position angle is often not accurately detected because of faults in motor making, pulse loss of linear encoders, and so on. In order to precisely control the currents of PMLMs, a compensation scheme of position angle errors is proposed based on the mathematical relation between position angle errors and currents. In the scheme, a position angle error compensator is designed to compensate the position angles detected by linear encoders. Furthermore, a filter and a class of iteration learning algorithm are proposed to avoid the errors produced by detected phase currents and phase voltages. Simulation results show that position angle errors of PMLMs are fully compensated. Using the designed position angle error compensator, currents can be controlled in a more precise manner.

Research on secure buyer-seller watermarking protocol

A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyers watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.

A Redundant-Sensor-Based Fault Reasoning Technique for Multi-Sensors

In magnetic bearing systems or other relative devices with multi-sensors which states are not easy to be monitored and tested, multi-valued logic algebra based on sequential variables is suggested to be utilized in the fault diagnosis of the multi-sensors. The states of sensors and devices are both discretized to be three logic values: normal, abnormal and a transition state between them. On the basis of proving several relative theorems that can reveal the relation between the states of the sensors and that of the devices, the experiment arrangement is discussed in detail when the state of a device is anyone of the three states respectively. All the completed experiments should be necessary and be without redundant ones. A novel redundant-sensor-based fault reasoning technique is presented to be used for fault diagnosis of multi-sensors according to the experiment results. The reasoning result shows that it is not in all the occasions that the state of every sensor can be determined. Fault diagnosis should be carried out early when there are not too many sensors with fault.

H ∞ filter design for uncertain descriptor systems

In this paper, the problem of Hinfin filter design for uncertain descriptor systems is investigated. We consider designing state space filters and descriptor filters for descriptor systems. Via using linear matrix inequalities (LMIs), sufficient conditions are established for the existences of the filter such that the uncertain error systems are admissible and their transfer functions from the disturbance to the filtering error output satisfy a prescribed Hinfin-norm bound constraint. By solving LMls, explicit parameterization expressions of all desired state space filters and descriptor filters are obtained. Furthermore, all these results involve no decomposition the original descriptor system matrices, which makes the filter design procedure simple and direct. Simultaneously, we still optimize its Hinfin performance for uncertain error systems.

Research on the architecture of Web-based distributed cooperative design system

Web-based distributed cooperative design is an important enabling technology in the implementation of advanced manufacturing. According to the analysis of the requirements of cooperative design system, a three-layer B/S architecture of browser, Web server and database is presented in this paper. By comparing this architecture with the traditional one, which is composed of client layer and server layer, this paper discusses the functions of these three different layers and the internal relations between them at length. The proposal of this architecture lays a foundation of establishing a flexible and effective cooperative design system under the circumstance of network.

Study of detecting impact damage for composite material based on intelligent sensor

A system of impact damage detection for composite material structures by using an intelligent sensor embedded in composite material is described. In the course of signal processing, wavelet transform has the exceptional property of temporal frequency localization, whereas Kohonen artificial neural networks have excellent characteristics of self-learning and fault-tolerance. By combining the merits of abstracting time-frequency domain eigenvalues and improving the ratio of signal to noise in this system, impact damage in composite material can be properly recognized.