bluuebunny/crossref_metadata_2025 huggingface dataset:
A Robust Controller for Positioning Control of Pneumatic Servo System: Design and Experiment Tests
Authors: Zhang Zhong Jie
Published: October 2014

The pneumatic cylinders are difficult to be controlled due to flow characteristics of control valves, compressibility of air, and static and dynamic friction forces. This paper describes the development of a robust controller based on H∞ control theory for positioning control of a high-speed pneumatic cylinder. To design the H∞ controller, one has selected appropriate weighting functions of pneumatic servo system.Simulation results show that the system is robust during the whole response process and can suppress the disturbance. Finally experiments have been performed with varying supply pressures and load mass. Experimental results imply that good performance and robustness of positioning in pneumatic servo system can be obtained using H∞ controller.
Application of Fuzzy Control Simulation Human Intelligence Controller in Ferment Process of Supplying Suger
Authors: Wang Lei , Feng Qian
Published: October 2014

In accordance with the features of non-linear, large time-delay and time varying for ferment process, an algorithm combining Fuzzy Control and Human-simulation Intelligent control is presented: Fuzzy control and human-simulating control algorithm is used to control the ferment process of supplying suger. The simulation research shows the algorithm is a very effective algorithm with very good anti-delay and anti-disturbance, especially suitable for the objects with large time-delay and strong disturbance.
Application of Hybrid Petri Net in Modeling of the Energy System in the Iron-Making Process
Authors: Wang Hong Jun , Gao Kun , Zhao Hui , Yue You Jun
Published: October 2014

Energy model is an important part to research energy system of iron and steel enterprise and the basis of energy saving. Based on the analysis of iron steel enterprise production process, material and energy employed in the iron-making process were extracted. According to the hybrid characteristics of energy systems in iron and steel enterprises, the hybrid Petri net was used for modeling material and energy of the iron-making process. The MATLAB simulation with the stateflow toolbox based on hybrid Petri net was given. The model was proved that it was able to provide further support to energy conservation and control in the actual production.
Application of the Wavelet Fuzzy BP Network in the Automotive Fault Diagnosis
Authors: Lu Bing Yan
Published: October 2014

Combined with the wavelet analysis, the fuzzy theory and the BP neural network this paper constructs the fault diagnostic method of the wavelet fuzzy BP network. In the process of the automotive fault diagnosis, through comparing the common BP neural network with the wavelet fuzzy BP network, the result indicates that the wavelet fuzzy BP network has the characteristics of higher precision and faster convergence speed etc.
Model-Based Design on the Application of Active Flow Control System
Authors: Shi Liu Wu , Wu Nai Ming
Published: October 2014

Active flow control has produced a great many values in the S-shaped inlets. In this study, the pressure gradient is used to characterize the degree of flow reattachment on the S-shaped inlet and be referred as the pressure recovery parameter[1]. A transfer function is established between an input of frequency of the solenoid valve and an output of the pressure gradient. According to the process of model-based design, one of Simulink model created by Different Control Algorithms which are applied to the established system in the simulation is selected to generate C codes automatically. The generated codes are embedded in the ARM7 processor and the test result of the processor is consistent with simulation.
Petri Net Automatic Modeling Method Based on System Behavior Sequence
Authors: Fan Hao , Shu De Qin , Zhang Liang
Published: October 2014

If you want to simulate and analyze a system by Petri net, you must construct a reliable and accurate Petri net model. Problem of constructing model by Petri net is discussed few at present. Petri net automatic modeling method based on system behavior sequence is presented. This method combines all the behavior sequences of system into the formal language expression. For different system, giving labeled function (giving the relationship between transition and system behaviors) can construct system Petri net model. To illustrate the algorithm, an example of constructing user Petri net model of telephone call service is given. This method has strong formalization and can be used universally. The model constructed by this method is standard and can realize computer automatic modeling. It makes progress in research of system modeling.
Robust Predictive Control for NPC Grid-Connected Inverters
Authors: Wang Lu Jun , Gong Tao , Zhu Jun
Published: October 2014

In this paper, the state space model of neutral point clamped three-level grid-connected inverter is detailed derived and an Robust Predictive Control (RPC) method is proposed. In the proposed method, the total 27 switching vectors composed of a finite set from which the optimal switching vector is selected according to a cost function. The robust performance is improved just by increasing switching frequency. Experimental results show that the proposed method has a flexible control purposes and we can optimize the synthesize performance just by adjusting weighting coefficients of cost function. In addition, RPC controller has a robust performance in tracking output reference current and balancing neutral point voltage.
Simulation and Parameter Optimization for Vibration Control System of MLRS Launcher
Authors: Zhao Xian , Luo De Qing
Published: October 2014

Vibration suppression of the launcher is an important way to improve the firing accuracy of Multiple Launch Rocket System (MLRS). In order to get a better control result from the course that pulse control mechanism generates pulses to restrain the vibration of MLRS launcher, this paper analyzed the process that pulse thruster control the vibration of launcher under the modulation of pulse width and pulse frequency (PWPF) modulator. And the simulation model of the control system is established through the SIMULINK software in MATLAB. Under repeated modifications of the structural parameters of PWPF modulator, the influence laws of these parameters are found out, and the best structure parameter values are obtained. The final simulation result shows that the vibration in the pitch and lateral direction is greatly reduced. It is a big help to improve the firing accuracy of MLRS.
The Design and Implementation of Automatic Verification System of Anemometer
Authors: Lu Hui Guo , Jiang Juan Ping , Li Cong Ying , Wang Li
Published: October 2014

This design makes the anemometer verification automatic and realizes the management of equipment information through the establishment of wind tunnel laboratory automatic verification software system. It integrates fan control device owned by the apparatus, data acquisition system and equipment information management to achieve the goal that we can record or select the information of inspected instruments, standard devices and verified data, and make data acquisition and calculation automatic by using the software platform. The system also has the function of generating verification log sheet automatically. The establishment of the system can reduce the error prone by manual operation of verification staff and enhance working efficiency thereby improving the efficiency and quality of the anemometer verification work.
The Fuzzy PID Control Simulation Research of the Macro-Micro Servo Driven Positioning Mechanism
Authors: Xu You Xiong , Zhu Song Qing
Published: October 2014

According to the contradiction between the large stroke and high precision of positioning mechanism, in order to solve the high precision positioning problem of large stroke motion system in precision machining and precision measurement fields, the macro-micro positioning mechanism based on electrohydraulic-piezoelectric hybrid servo was presented with the advantages of the electrohydraulic servo driven and the piezoelectric precision driven. Its combined simulation model based on AMESim and MATLAB/Simulink software was built. On this basis, its fuzzy PID control simulation research was done. The simulation results showed that compared with traditional PID, the positioning mechanism static and dynamic performance could be improved by using the fuzzy control method. This will provide control theoretical basis for practical engineering applications.
Data-Driven Based Temperature Prediction of Ferroalloy Electric Furnace Smelting Process
Authors: Zhang Niao Na , Liu Xu
Published: October 2014

Aiming at the features of nonlinearity, time delay, high dimension, big noise and others in the electric furnace smelting process, and the smelting process parameters some control process needs cannot be obtained by sensors, so the online parameter prediction method is of great significance for dynamic optimization control of system. In this paper, by using chaos theory and phase space reconstruction method, based on the idea of data-driven modeling, the temperature prediction model of crucible in the smelting process of ferroalloy electric furnace is established based on multivariate time series. Experiments show that the established data-driven prediction model can well predict the temperature change in the electric furnace smelting process, the root mean square errors of prediction are respectively less than 0.0715,and this has good guidance for practical production.
Robust Integrity Design for Uncertain NCS with Actuator Saturation Based on Discrete Event-Triggered Communication Scheme
Authors: Cao Hui Chao , Li Wei
Published: October 2014

This paper investigates the co-design problem of both robust integrity and the usage of communication resources for a class of actuator-saturated networked control system(NCS) based on a novel discrete event-triggered communication scheme(DETCS). First, a new model of NCS is established that parameter uncertainty, network-induced delay, actuator saturation and faults, and the state error arising from the DETCS are taken into consideration in a unified framework. Second, based on the model, the set of invariance condition of the closed-loop fault NCS with actuator saturation is proposed, which is the delay-dependent and event-dependent sufficient condition for ensuring the system stability. Then, a co-design approach which includes both robust fault-tolerant controller and the corresponding trigger weight matrix is given via linear matrix inequalities. The reciprocally convex combination lemma and the improved Jensen integral inequality are employed to deal with the derivative terms of the Lyapunov-Krasovakii functional, which can reduce the conservatism and computation of the results. Finally, a simulation example is used to demonstrate the advantage and the effectiveness of the proposed co-design approach, meanwhile, the quantitative relationship between the system performance and the communication resources is provided.
Structural Phase Stability and Electronic Properties of Magnesium under High Pressure from First-Principles Calculations
Authors: Liu Qiu Xiang , Zhang Rui Jun , Zhang Fang
Published: October 2014

First-principles pseudopotential calculations have been performed to investigate the structural stability and electronic properties of magnesium considering three possible structures under high pressure. The results show that magnesium crystallizes in the hcp structure is to be the most stable structure at the ground state, because of the lowest total energy. Magnesium undergoes a pressure-induced phase transition from the hcp structure to bcc structure at 65 GPa. And no further transition is found up to 220 GPa. The electronic structure properties of three structures of magnesium are also calculated and discussed. The structural stability mechanism is also explained through the electronic structures of three phases.
Analysis of the Energy Metering Problem in Dynamic Environment
Authors: Wang Zhuo , Bao Hai
Published: October 2014

The traditional electric power metering theory is a kind of no-error metering theory in sinusoidal steady-state circuit. However, the applying condition is too rigor, and the engineering environment is hard to fulfil, the application premise should be extended to dynamic. Ideal linear elements are adopted to build a first-order dynamic circuit. And the analytic expressions of the capacitor cumulative electric energy in the charging process are derived theoretically. It points out that the cumulative electric energy of capacitor in dynamic circuit is a nonzero value. This fully demonstrates that the energy metering principle brings error when it is used in dynamic environment.
Characteristics and Analysis of a New Type of Hybrid Compression Energy Storage System
Authors: Zhang Li Wei , Zi Xing Xing , Huang Xian Jin
Published: October 2014

Based on the background of compressed air energy storage system (CAES), this paper analyzes hybrid compression energy storage system (HCES) firstly. Design a new type of energy storage system - cyclic compression energy storage system (CCES). Secondly, study its working principle and characteristic parameters, such as compression-release efficiency, energy density and so on. Finally, by simulation and parameter calculation, prove the correctness of the theoretical analysis.
Scheme of Protection and Monitor Underground High-Voltage Power Supply System Based on PROFINET
Authors: Liu Hai Bo , Wang Yu Mei
Published: October 2014

Short circuit protection of high-voltage power lines in coal mine cannot realize selectivity with existing protection systems. To solve this problem, a scheme of protection and monitor underground based on PROFINET was proposed. The system is mainly composed of PROFINET network, monitor, controller, and integrated protector with PROFINET IO interface circuit. The system achieves protection and power monitoring network integration, completes the selectivity of short circuit protection, and can determine fault position quickly. Thus the troubleshooting time is cut and reliability of power supply network is improved. The simulation results show that the POROFINET real-time meets the requirement of protection and the system can realize short-circuit protection and power monitor function.
Master-Slave Joint Power Flow with Wind Power Generators
Authors: Wang Yan Ling , Zhou Xiao Feng
Published: October 2014

First based on the analysis of dynamic characteristics of wind power generators, the uniform extended flow model for transmission-distribution joint with wind power generators is derived. The master-slave decomposition and coordination solving methods is proposed. Master-slave system joint calculation, considering the affect between each other, realized the joint integration calculation of power system and improved the verisimilitude of results. And, the dynamic characteristics of dynamic element of the master-slave system are considered, and it makes the results more practical. Finally, through 94-node example system analysis, the effectiveness and necessity of the proposed model and method is verified.
Role-Based Services Certification Model of State Grid Unified Application Platform
Authors: Zhou Cheng , Li Qian Mu , Shi Jian
Published: October 2014

With analyzing the cause and characteristics of security problems in the current power State Grid Unified Application Platform, this paper proposes a Role-Based Services Certification Model, RBSCM, to solve the security problems in electric power information system and designs a generalized and effective mechanism of security management. The paper provides a set of constraint specifications. These constraint specifications of RBSCM are organized to form a construction, and an enact process is proposed to make it scalable and flexible to meet the need of diversified service application systems.
A Novel Rectenna Design with DGS Filters for Low-Power Energy Transfer
Authors: Liu Shuang Bing
Published: October 2014

A high efficiency rectifying antenna (rectenna) is designed at 5.8 GHz by using defected ground structure (DGS) filters for low-power energy transfer. A slot-coupled patch antenna is used as a receiving antenna with a high gain of 8.2dB. A DGS low-pass filter at the input port of the rectifying circuit is used to suppress the high order harmonics by 20dB. A DGS dc-pass filter is designed to block the AC signal from transmitting to the load. Both of the antenna and the filters are simulated by the full wave EM analysis software of HFSS. The RF-DC conversion efficiency of 51.8% is obtained when the received power is as low as 3mW.
Synthesis of a Cholesterylated Compound Containing Carboxyl Functional with PEG2000 Chain for Hepatic Targeting Liposome Ligand
Authors: Wu Xiao Chun , Hai Li , Wu Yong
Published: October 2014

A carboxyl functional cholesterylated compound for hepatic targeting liposome ligand T1 was synthesized. Cholesterol as starting material, after esterification with p-toluenesulfonyl chloride to get cholesterol tosylate M4, then etherification with tetraethylene glycol to get hydroxyl functional M3, M3 react react with methanesulfonyl chloride to get M2, M2 was elongated by reaction with PEG2000 to get M1 and M1 react with succine anhydride get T1. The target compounds afford cholesterylated hepatic targeting liposome ligands.
Application of PLC and RSView32 in Coal Mine Belt Transmission System
Authors: Ma Qiu Huan , Sun Wei Li , Zeng Shi Xian , Ge Wei Wei
Published: October 2014

The surface centralized control system of belt transmission of coal mine is the main channel coal transmission in coal mine, whether or not to normally operate directly affect the safety of coal production and economic benefits. With the expansion of coal production, the original capacity and safety of the belt transport cannot meet the development needs of the current. In response to the problems above, this system will the surface belt transmission of coal mine factory. Focus on control, to realize centralized control of the system. And perfect testing and protecting of the most vital part of the system.
Controllable Tuning of the Spin-Dependent Transport in the Graphene Sheet
Authors: Liu Chun Mei , Li Zhuan , Wang Jun Ling , Zhao Li Li , Wang Yang
Published: October 2014

Based on the non-equilibrium Green’s function in combination with the density-functional theory, The spin-dependent transport in the short graphene nanoribbon (graphene sheet) asymmetrically coupled to the electrodes of Au chains is investigated. It is found that a fully spin-polarized current (close to 100%) can be produced at the output port. The physics underlying attributes to the spatially separated edge states of the sheet caused by asymmetric contacts. Especially, the current's spin polarized direction can be tuned simply by changing the contact locations of the electrodes to the graphene sheet.
FPGA Based Frequency Correction of Master Clock Terminals of Whole-View Test Systems
Authors: Luo Bi Lu , Huang Qi , Cao Li Yue , Yang San Gen , Hu Xiao Dong
Published: October 2014

Aiming at the problem of low accuracy and insufficient stability of master clock terminals frequency in Whole-view Test Systems, in this paper, a simple and effective method to Correct frequency of OCXO (Oven Controlled Crystal Oscillator) have been proposed. This approach based on the principle of establishing time system within FPGA, with TDC (Time to Digital Converter) measure the periodic deviation between OCXO and GPS, modifying the value of period within FPGA, reaching the purpose of frequency correction. To reduce the impact of GPS signal jitter, the moving average filter algorithm has been used to tame OCXO quickly. Through simulations and experiments, the clock frequency accuracy is higher than the average 5×10-10, and the time accuracy is better than 1.8μ/h.
Image Acquisition System Design of Camera Based on FPGA
Authors: Zhu Jun Chao , Li Yong Chen , Jiao Ying Kui , Ma Zhi Jun
Published: October 2014

It designs an image acquisition system of the camera based on FPGA. It uses a CMOS image sensor as the sensitive chip and controls the timing of image collection by designing the FPGA. FPGA transfers captured image into a PC to display. It uses the I2C bus to initiate CMOS sensor. A problem of cross-clock is solved by asynchronous FIFO. By the ping-pong operation based on two SDRAM chips to solve the problem of high speed data cache. The FPGA chip communicates signal data with PC by Ethernet port. The experiment proved that the system is able to collect 2048×1536 resolution images in a speed of 12fps.
Research on PZT Phase Modulator Applied in Optical Cable Identification Device
Authors: Sun Qiang , Liu Guang Chao
Published: October 2014

The optical cable identification device is based on Sagnac interference principle, which is able to sense the optical phase shift.Phase modulation can improve the sensing sensitivity.In this paper,the feasibility of the piezoelectric ceramic used as phase modulator and its application in optical cable identification device have been analyzed theoretically. We have designed a PZT phase modulator by using P-5 type piezoelectric ceramic tube.Finally, the modulation principle of the PZT phase modulator has been tested by using optical cable identification device. The PZT phase modulator has a good linearity at 10KHz,the PZT phase modulator can be applied in the Sagnac optical cable identification device.
Improvement of the Analog Data Acquisition Accuracy Based on the Oversampling Technology
Authors: Yang Chun Song , Chen Xin , Lv Xun Hong
Published: October 2014

Unmanned aerial vehicle (UAV) flight control system often needs the acquisition of sensor signal in analog form. In that case, the accuracy of the analog signal acquisition has a very important influence on the UAV flight control system. During the collection of analog signal, noise can have a negative effect on the accuracy of this collection, so we need to filter out the noise. However, some kinds of noise cannot be filtered out with hardware filters, which makes it necessary to combine oversampling technology and digital filters. In this paper, we make use of own-designed circuit to discuss some relative problems about the improvement of the analog data acquisition accuracy with oversampling technology which Verify the effectiveness of the oversampling method by comparing the traditional sampling method and the oversampling technology.
The Design of Avionics System Interfaces Emulation and Verification Platform Based on QAR Data
Authors: Sun Yi Gang , Sun Li
Published: October 2014

In order to avoid the complex mathematical modeling and ensure the reliability of avionics system verification, this paper has designed an interfaces emulation and verification platform of avionics system based on QAR data. Platform includes 2 parts: Emulator and Simulator. Simulator generates the flight environmental data which is come from QAR and transforms the data into excitation signal of devices. Emulator emulates the interface features of avionic devices according to the ICD and can be replaced with real devices. By comparing the actual input-output data of devices with QAR theoretical data, this platform can evaluate the running performance of avionic systems or devices and the rationality of the ICD.
Ellipsometry Analysis of MgxZn1-xO Films on Silicon Substrates
Authors: Yu Yuan Xun , Lian Jie , Guan Wen Li , Yu Xiao Hong
Published: October 2014

MgxZn1-xO films with hexagonal structure are prepared by radio frequency (rf) magnetron sputtering on Si substrate. The refractive indices and absorption coefficients of these films in the wavelength range from 300 to 800nm are determined by using ellipsometry at room temperature. The results show that the refractive index increases as the wavelength decreases in the transparent region (400-800nm). It reaches its maximum value around 340nm and 331nm, which is close to the fundamental absorption edge. Then the refractive index decreases as the wavelength gets shorter. The value of the refractive index is also a function of the Mg content. The higher the Mg content is in the film, the smaller the refractive index of the film is in the wavelength range from 330nm to 850nm. The band gap energy of the MgxZn1-xO film is obtained by analyzing its absorption spectrum. An increase in the Mg content causes the fundamental absorption edge to shift toward shorter wavelength. In addition, UV and strong blue emission have been observed when the MgxZn1-xO film is excited with light wave of 260nm at room temperature, and the emission mechanism is discussed.
The Influence of Time Truncation on Phase Angle Measurement Principle
Authors: Chang Na Na , Bao Hai
Published: October 2014

Real-time accurate voltage phase angle measurement data has a very important significance to monitor and analyze the power system, and phase angle measurement principle of Fourier transform plays an important role in the theoretical calculations and engineering applications. The dynamic sinusoidal voltage signal contains two parts of the sinusoidal steady-state component and decaying DC component, and the decaying DC component having a continuous spectrum, at the frequency corresponding to the sinusoidal steady-state component must have a non-zero value, making dynamic signal phase than steady signal phase has one extra deviation angle. Considering Fourier transform method and theory of engineering application are different, this paper only considered the application conditions of time truncation, analyzes continuous Fourier transform under a real eigenvalue and a pair of conjugate complex roots condition, then compared with the theoretical calculation, for the two case of limited time integration and theoretical calculation condition, the phase angle difference and influencing factors are given.
Design of Rain Sensor Based on Optical Principle
Authors: Chen Hai Xiu
Published: October 2014

An optical rain sensor which can be used in automobile is described in this paper. The sensor is mainly composed of light source, light collimation system and light focusing system. When it rains, the rain sensor detects the rainfall on the automobile’s windshield surface through the light from the transmitter, and the light intensity received by the sensor receiver can be used to control the wiper to work automatically. The structure of the sensor is designed and the corresponding optical simulation is finished. With the optical rain sensor, the wiper device can work automatically and adjust the swing speed with the rainfall. The performance of automatic control of automobile and the driving safety are also improved.
Research on the Attenuation Law of Metal Magnetic Memory Testing Signal
Authors: Zhang Yuan Liang , Lv Yan , Zhang Hao , Wang Jin Long , Zhang Gui Jie , Zhao Jia Xu
Published: October 2014

In order to clear the timeliness issues of metal magnetic memory signal value after unloading, we conduct some static tension experiments on some specimens in materials of KMN, which is commonly used in centrifugal compressors? Furthermore, we analyze the specimen, which is prefabricated artificial defects, on the surface normal magnetic field strength decay law with EMS-2003, the intelligent magnetic memory tester. The results show that: the surface magnetic field signal value is reduced by time after unloading, in other words it has certain timeliness.
Breakdown Process of Pseudospark Discharge Using the Various Discharge Module
Authors: Gu Xiao Wei
Published: October 2014

A argon Pseudospark discharge is studied and modelled with our developed simulation program. The structure of our code is flexible and transparent. The modular structure is divided into three main parts: electromagnetics module which forms the heart of the model, the neutral gas module, and the chemical reaction module. The above three parts with the plasma module are controlled by the user. The strong modularity makes the code easy to handle and easy to adjust or expand. This project will do in-depth numerical simulation for the study of the inception of breakdown characteristics via a electrostatic particle-in-cell plus Monte-Carlo collision method. The model tracks the trajectories of both electrons and ions, including ionizing collisions in the gas phase by electrons and ions, and secondary electron emission by ions on surfaces. The result indicated the pseudospark discharge breakdown process mainly induced by field emission.The peak discharge current is found to be dependent on gas pressure,electrode borehole diameter. The effect of these design parameters on the peak anode current has been analysed. Simulate the discharge breakdown physical processes for the Pseudospark in order to lay the theoretical foundation for the optimize and improve the pulse power electron beam.
Effects of Groundwater Heat Pump Systems on the Temperature and Quality of Groundwater in Recharged Aquifer
Authors: Li Bing Hua , Cao Xiao Juan , Liu Li Cai , Zheng Fan Dong , Zhang Ni
Published: October 2014

Groundwater heat pump (GWHP) systems in three different hydrogeological fields, Beijing were selected, and their effects on temperature of groundwater in recharged aquifer were researched for three years. Results showed that the degree of thermal breakthrough was controlled by the distance between pumping wells and injection wells, and the temperature of groundwater with high flow rate can recover to normal faster than those with low flow rate. When distance between pumping wells and injection wells were shorter than 30m, thermal breakthrough may happen and the variation range of groundwater temperature during one heating or cooling period was 8~12°C.However, thermal breakthrough can be negligible and the temperature of groundwater may be steady when the distance between those wells was longer than 50m. Furthermore, GWHP in two different hydrogeological fields were selected to observe their effects on groundwater quality for one year. One GWHP was situated on the northwest piedmont alluvial fan of Beijing and the other was located in the southeast plain area of Beijing. Groundwater was sampled from those fields and thirty-two inorganic components were analyzed. Heavy metals were not detected, and calcium, magnesium, chloride, sulfate, fluoride and other ten inorganic components were studied. Groundwater quality in the northwest of Beijing was relatively steady because that aquifer was in relative oxidation environment. However, groundwater quality in the southeast of Beijing was subject to change because that aquifer was in relative reduction environment. Nitration reaction happened in the plain area, and ammonia, nitrite converted into nitrite nitrogen and nitrate nitrogen, respectively. Simultaneously, pH, concentrations of iron and manganese decreased, and total hardness increased.
Global Performance Estimation Based on Gaussian Mixture Model for Wind Turbines
Authors: Wang Wei , Zhang Meng Hang , Guo Shuang Quan , Li Hui , Lv Wei , Yang Jia Rong , Liu Zong Chang
Published: October 2014

In order to ensure that the wind turbines are reliable in stable condition and economical in maintenance cost, the most effective way is to estimate and monitor the performance and operation of the wind turbine. Traditional fault diagnosis methods using multivariate statistical process usually assume the unit only has a single operating condition, so it’s not suitable for multi-regimes. Aiming at this problem, this paper proposed a global performance estimation method of multi-regimes condition based on Gaussian mixture model (GMM). First establish GMM to train the baseline model, cluster the sample data using the similar GMM method, and then calculate the distance between the baseline model and the GMM of sample data by two different methods. The result shows that this method can identify the characteristics of the turbine productivity well, and can detect the abnormality of power curve that is related to incipient fault.
Finite Element Analysis of Wind Vibration Control Effect for Single Transmission Tower
Authors: Xie Wen Ping , Xia Dong Zhou , Yang Wei Jun
Published: October 2014

Three-dimensional finite element analysis model of transmission tower is established by using ANSYS software. According to the characteristics of the tower, wind vibration control effect of transmission tower is to be studied through seven different kinds of distribution of MR dampers condition, then get the dynamic response in different position of the tower body and tower top. The analysis results show that:: Through using of different damper layout, it can reduce vibration of the tower, especially the third scheme which is tower head lower half part edge member bar plus dampers had the most significant vibration reduction effect. Research results can be reference for engineering design and engineering practice, it also has a certain theoretical and practical significance.
Study of Wind Induced Vibration of Transmission Power Tower-Line System
Authors: Yang Wei Jun , Liang Long Teng
Published: October 2014

This paper reviews the study of wind induced vibration of transmission power tower-line system. Each fields of research of transmission power tower-line system —analysis model, dynamic characteristic, wind response and vibration control —are systematically introduced. the problem that exist in this stage and the development trend are summarized in the conclusions.
Study on Mechanical State Diagnosis of Power Transformer Winding Based on Vibration Method
Authors: Zhang Bin , Chen Jiang Bo , Li Hui , Xu Jian Yuan
Published: October 2014

This paper uses the vibration method to diagnose the mechanical state of transformer winding,directed against the fact that the accuracy of the mechanical fault diagnosis in transformer winding is not high. It collects the load test vibration signal of transformer winding in normal and abnormal state, analyzes the vibration signals in different states, and use the vibration frequency and load current matching to judge the winding condition. By setting the different faults to the actual transformer winding of S11-M-500/35 type, it uses the vibration method to do the diagnosis analysis. And the research content is of great significance for the promotion and application of vibration analysis method.
A Flextensional Transducer Prototype with PVDF Piezoelectric Film
Authors: Liu Jing Jing , Qin Lei , Wang Li Kun , Zhong Chao , Zhang Bin , Gu Chuan Xin , Long Dan
Published: October 2014

This paper presents a prototype of a new flextensional transducer with PVDF (Polyvinylidene Fluoride) piezoelectric film instead of metallic shell. Resonance frequency, bandwidth, transmitting voltage response, and horizontal directivity of the flextensional transducer with PVDF piezoelectric film were respectively measured by using laser-scanning vibrometer, and underwater acoustic measurement system. Experimental results showed that the new transducer features effectively conversion from longitudinal vibration of piezoelectric stack into radial vibration of PVDF piezoelectric film.
A Sensitive Formaldehyde Sensor Based on Cataluminescence Coupled with Thermal Desorption
Authors: Yang Hong Wei , Xing Zheng , Zhou Kao Wen
Published: October 2014

A sensitive cataluminescence-based detecting technology using nanosized Mo4V6Ti10O47 as a probe was proposed for determination of formaldehyde in air. Trace formaldehyde was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 75°C to determine. The method showed high selectivity to formaldehyde at wavelength of 575nm, satisfying activity at temperature of 260°C and good stability at carrier flow rate of 145 ml/min. The linear range of CTL intensity versus concentration of formaldehyde was 0.04~78 mg/m3, and the detection limit (3σ) was 0.02 mg/m3. The recovery of artificial sample was 96.8%-103.4% by this method. There was no response to CO, CO2, SO2, NH3, methanol, ethanol, benzene, toluene and xylenes.
Growth of Mo Thin Films on Flexible Polymer and Metal Foil Substrates for Solar Cell Application
Authors: Xu Jia Xiong
Published: October 2014

The Mo thin films have been used as the back electrodes of Cu (In,Ga)Se2and Cu2ZnSn (S,Se)4thin film solar cells. In this study, the Mo thin films were sputtered on flexible polyimide, polyethylene terephthalate, stainless steel foil, Ti foil, and Al foil substrates. The experimental results indicate that the Mo thin films with promising properties can grow on different flexible substrates. The favourable substrate material is stainless steel foil. By post-annealing, the average sheet resistance of Mo thin film on stainless steel foil substrate reduces to 2.05 Ω/sq.
Research on Measuring Methods on Explosion Seismic Waves
Authors: Chen Hao , Kong De Ren , Tong Xiao , Yang Fan , Li Li Ping
Published: October 2014

In engineering practice, geotechnical particle vibration speed is usually regarded as stability criterion of explosion seismic wave. However, when using explosion seismic wave to evaluate damage effect of shock wave, it is needed to study characteristics on other physical quantities of explosion seismic wave. By establishing test system of explosion seismic wave, seismic acceleration signals of 4 rounds of ammunition in air explosions are measured in three directions. The results show that the test system is reliable and effective.
A PXI-Based Biomedical Electrical Impedance Tomography System
Authors: Chen Xiao Yan , Yang Tao , Yang Yong Zheng
Published: October 2014

This paper presents a PXI-based biomedical electrical impedance tomography (BEIT) system and interprets how to build up a practical BEIT system quickly. The hardware platform of the system is composed of signal source module, switch module, signal conditioner module and PXI-6251 data acquisition card supplied by National Instruments (NI), which simplify the system structure as well as improving the stability and accuracy of the system. Different from the traditional BEIT systems, the electrodes selection, the switch pattern, the programmable gain amplifier (PGA) gain selection are realized by code programming in LabVIEW instead of electrical components design. The composition of the proposed system and the specialized software package developed in LabVIEW are introduced in detail in the paper, and experiments are undertaken to verify the feasibility of the system. The imaging results verify that the PXI-based BEIT system has prominent performance in flexibility, reliability and scalability.
Embedded Smart Textile Detecting Equipment Base on Flexibility Sensors
Authors: Wu Yu Chuan , Xue Yong , Hu Feng
Published: October 2014

This paper considers the application of flexibility sensors and wearable technologies on smart textiles to enhance the functionality of clothing and protective textiles for the benefit of people, especially older people. By introducing flexibility sensors based strain sensors, we can find its potential of the flexibility science in developed clothing and protective textiles. It has promising application on smart textile products and services appropriate to the needs and aspirations of active users. It shows us how the appropriate design of flexibility sensors has the potential to promote independence and wellbeing, and may enable participation in healthy exercise in the everyday lives of the active ageing.
Development of On-Line Monitoring System for Large Rotating Machinery under Complex Circumstance
Authors: Xu Ping , Yi Jian Gang , Zhao Li
Published: October 2014

Large rotating machinery is widely used in industrial production process. With the computer network technology, system testing technology, signal analysis and fault diagnosis technology, large motor based on high speed wire rod production line as the object, the online monitoring method of large motor is present. Based on it, the signal processing approach of large motor under complex circumstance is proposed, and the software of on-line monitoring system for large motor is developed. Through monitoring the key parameters of the distributed signals of temperature, pressure, current and so on, the developed system can accurately analyze and locate critical faults of equipments, reduce faults rate, extend the service life and increase productivity of the motor equipment.
Improving the SNR of SWD Data by Adjusting the Impact Energy of Drilling Tools
Authors: Wang Yao Kui , Yang Rui Zhao , Chen Nan , Zhang Tian , Liu Ji Fu
Published: October 2014

Seismic while drilling (SWD) technology, taking advantage of the vibration signal generated during the drill bit breaking rocks in drilling operations, has been used in the seismic explorations. Since the energy of signals produced by the seismic origin is weak while the noise jamming in the drilling site is strong, the signal-to-noise ratio (SNR) of collected SWD data is usually fairly low. In this paper, we focused on improving the SNR of SWD data via adjusting the impact energy of drilling tools. Based on the explanation of the working principle of SWD systems, the energy formation modes of three kinds of drilling tools were discussed. It was safe to expect that the hydraulic torque impactor could be applicable to improve the SNR of SWD data in evidence.
Accurate Measurement and Digital Modelling of Complex Surface
Authors: Liu Yan Qiang , Cheng Hong Xun , Wang Yan Zhong , Wang Jian Shen , Sun Ya Peng
Published: October 2014

Accurate measurement and modeling of complex surface is the foundation to precisely evaluate the error of complex surface. According to the NURBS method for rebuilding complex surface, a sampling data automatic replenishment method based on neural network is proposed and the sampling data with high precision is acquired. By using bicubic NURBS surface fitting method, the complex surface is rebuilt precisely and efficiently.
Research of Material On-Line Identification Based on Terahertz Spectrum
Authors: Zhang Qing Hua , Chen Xiai , Ke Shuang , Han Lu , Zhou Zhi Long
Published: October 2014

A material on-line identification system based on THz time-domain spectroscopy using VC was developed in this paper. The main functions including data reading, linear motor driving, the calculation of optical parameters, the display and management of curve, the management of interface, the analysis of historical data , the maintenance and updating of database, and on-line identification based on principal component analysis were realized. As the prototype of material detection application, the material whose corresponding type characteristic spectrum has already existed in the database could be well identified.
New Monitoring System of the Refractory Lining Wear in the Blast Furnace Hearth
Authors: Dmitriev Andrey N. , Zolotykh Maxim O. , Chesnokov Yury A. , Chen Kai , Ivanov Oleg Yu. , Vitkina Galina Yu.
Published: October 2014

The monitoring system of the firebrick lining state of the blast furnace devil is offered. The mathematical description, algorithm and program of calculation the temperature fields in any vertical and horizontal cross-section of the devil lining are developed with use of the indications of the temperature sensing transducer (to 1000) in the oven lining. The systems of gathering, processing and information transfer from the temperature transmitters to a program database are used. This monitoring system is established on five blast furnaces of metallurgical plants of China.
Single-User Cyclic Spectrum Detector Design in Cognitive Radio
Authors: Guo Jie , Tang Lei , Dong Yan
Published: October 2014

Cognitive radio can improve the spectrum utilization efficiency of spectrum band. So spectrum sensing is the key technology in cognitive radio network. Our main task is to design a cyclic detector with better detection performance than energy detector. This paper studies single-user spectrum detector in cognitive radio networks, including cyclic spectrum detector and energy detector. We firstly analyzed the energy spectrum sensing mathematic model for comparison, then we proposed the new simulation model and detailed simulation steps of this cyclic spectrum sensing detector. Simulation results demonstrate that the cyclic spectrum detector has better performance than energy detector while the SNR of channel condition is low.
Vibration Analysis of Silicon Microgyroscope Based on Simulink
Authors: Tang Wei Feng , Qiu An Ping , Xia Guo Ming , Su Yan
Published: October 2014

To improve the anti-vibration capability of silicon mcrogyroscope, making it works well under the vibration environment, this paper analyzes the dual-mass silicon mcrogyroscope and did the following works. First of all, the operating principle, analysis parameters of silicon microgyroscope and the vibration condition are introduced. Secondly, this paper proposes a vibration analysis method base on the signal conversion between time domain and frequency domain and establishes a Simulink demodulation model according to circuits of silicon microgyroscope. Finally, we get the conclusion that under the condition of vibration, composition with the same frequency of Vds in Vsense signal is the main influence factor of bias stability by analyzing experimental data. This has a great significance for improving the anti-vibration capability and guiding the interior structure design of silicon microgyroscope.
A Study of Linear versus Kinked Bulky Polymers for Proton Exchange Membranes Using Sulfonated Polyimides
Authors: Li Yu Han
Published: October 2014

Linear and kinked bulky monomers were incorporated into the main chain of a polyimide in order to investigate the effect of kinked versus linear polymers on membrane properties such as water uptake and proton conductivity. Polymers prepared using linear 1,4-bis (4-aminophenoxy)-naphthyl-2,7-disulfonic acid (BAPNDS), SPI-N, and using kinked 2,2’-bis (p-aminophenoxy)-1,1’-binaphthyl-6,6’-disulfonic acid (BNDADS), SPI-BN, were cast into membranes. All the copolymers showed excellent solubility and good film-forming capability. Membranes are thermally stable up to 300 °C under air. For SPI-BN, the nonplanar binaphthyl group result in polymer chain relaxation and produce large water uptake. However, the conductivity of kinked, SPI-BN membranes is lower than those prepared from SPI-N for a given IEC but water uptakes are higher. This might be related to substitution position of the sulfonic acid groups and the microstructure. Sulfonic acid group were located at the same side of the main chain will be favorable for forming hydrophilic clusters, thus better proton conductivity performance would be achieved.
LRF-Based Human Following Robot by Tracking Legs
Authors: Wang Li Xian , Yan Rui Jun , Sheng Long
Published: October 2014

This paper presents a method to track and follow target person. A laser range finder (LRF) is used to measure highly accurate distance of objects with the range of 180 degrees. First of all, the erroneous data are excluded due to the error of LRF. Then all the raw sensor data are separated into many groups when the difference of the measuring distances of two adjacent laser points are beyond a limited value. For each group, the width is calculated, and it is considered as human legs if the defined conditions are satisfied. Finally, a real-time human following experiment with a SICK LRF and PIONEER mobile robot is done to validate our proposed method.
The Analysis of Multi-Rotor Attitude Simulator Based on Matlab
Authors: Zhao Zheng Xu , Han Li Long , Xu Qian
Published: October 2014

There exist overfrequency issues of airframe vibration, instable fight conditions, inefficient airframe survivability and undeveloped cockpit’s eject-ability insides multi-rotor aircraft flights. This paper focuses on four-rotor aircraft researches via gathering inherent rotor attitudes with the inertial motion capture device. Based-on the resulting data analyses, the relations between flight attitudes and rotor performances are clearly figured out. This research also advances multi-rotor aircraft works, such as: drawing frameworks, evaluating simulations, designing control systems, and optimizing safety and stability properties.