bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanics Analysis and Experiments of the Elastic Linkage for a Novel Asymmetrical Pitch System
Authors: Luo Jun , Xie Shao Rong , Li Heng Yu
Published: October 2011

Concerning to problems of the traditional machine pitch system for miniaturizing Micro Air Vehicles (MAVs), A novel asymmetrical pitch method is discussed in this paper. This novel method makes use of the deformation of an elastic linkage to generate the blade pitch meeting the requirement of the MAV flight mode control. Based on velocity control, phase control and mechanics analysis, Based on strain gauge and mercury conductive slip ring, mechanism experiments of deformation for different ratio of length and thickness and different elastic modulus of the elastic linkage which is key part in asymmetrical pitch system are done. From deformation curves of the elastic linkage, bigger ratio of length and thickness and smaller elastic modulus of the elastic linkage have bigger amplitude of deformation.
New Scheme for Vibration Test Applying 3-Axis Acceleration Sensors Array
Authors: Wang Wei , Jiao Jian Chao , Tang Li Wei , Yang Tong Qiang
Published: October 2011

Acceleration sensors array can effectively measure 6-DOF high-frequency vibration parameters of many dimensions linear vibration and angular vibration. In engineering, single axis sensors introduce several errors. They also require more space to fix in and increase the computational complexity. The new scheme applying 3-axis acceleration sensors instead of single axis sensors can solve the problem above with effect. Simultaneously, the feasibility of the scheme was verified by principle derivation and model simulation.
Node Design of Alarming System for Coal Gas Based on AT89C55WD and CAN Bus
Authors: Han Ying Jiang , Chen Zhi Yuan
Published: October 2011

According to the performance and features of AT89C55WD and CAN bus, a nod design method of alarming system for coal gas based on AT89C55WD and CAN bus is proposed in this paper. The hardware structure and the design process of software are discussed in detail. The hardware system consists of microprocessor AT89C55WD, CAN controller SJA1000 and CAN transceiver PCA82C250. Under the support of corresponding software, the gas density, temperature and humidity can be effectively monitored by this alarming system.
Material Selection and Application of Abrasive-Liquid Device Sealing Bush
Authors: Zeng Rui , Du Chang Long , Zhao Jing , Xu Rui
Published: October 2011

In order to make the switch valve in abrasive-liquid device of premixed abrasive water jet cutting system work normally, the sealing bush which ensures the pressure constant and the switch smooth is needed. The structure, material and craft of the switch valve sealing bush are studied in this paper. The different weight content of short glass fiber reinforced nylon is tested in the environment of no lubricant, water lubricant and oil lubricant. The result shows that in oil lubricant environment, the 33% weight content of short glass fiber reinforced nylon composites have the best capabilities and the least resistance of friction. The experimental result proves that the sealing bush made by the prepared short glass fiber reinforced nylon composites can meet the require of the premixed abrasive water jet cutting system, according to which the sealing bush is producted and assembled to the abrasive-liquid device.
Design of Stepping Motor Position Closed Loop Control System Based on PLC
Authors: Wang Li Hong , Zhao Yue Ling
Published: October 2011

A stepping motor position closed loop control system was designed, which adopts displacement sensor to examine the position of the load. The system’s hardware constitute was given here, and the pulse control project was given at the same time. It uses the high-speed pulse output of PLC to export the adjustable frequency pulse. The adjustment of the frequency based on the error of initial value and actual value. On one hand, it can realize fast and accurate position control. On the other hand, it can overcome the weakness of losing step. Thus makes the system have better control function.
Study on Machinery Cutting Technology of Ceramic Parts
Authors: Jiang Dong Mei , Wang Qiang
Published: October 2011

The machinability of ceramics is evaluated by data envelopment analysis, mathematical programming model is constructed, then the optimal solution of decision-making unit is found. These reference values of he tool rake angle, clearance angle, tool cutting edge angle, minor cutting edge angle, tool cutting edge inclination angle, tip ARC radius and cutting speed, back engagement and the range of feeds are obtained through by orthogonal cutting test, these processing parameters are optimized, then better processing results are achieved. Considering the problem of Machining of ceramic materials, the techniques of mechanical cutting process, ceramic turning, grinding, drilling, et al are discussed.
Effect of Variety and Morphology of Substrate on the Crystal Form of Calcium Carbonate Crystal
Authors: Ma Wen Jie , Wang Xue Wu
Published: October 2011

Based on the basic principles of biomineralization, calcium carbonate (CaCO3) which has specific shapes can be synthesized by the biomimetic synthesis, using three-dimensional (3D) photonic crystals self-assembled by polystyrene spheres as the matrix (Ps film).The effects of variety and morphology of substrate on the crystal form and morphologies of CaCO3 were investigated. It was found that variety of substrates has great influence on the phase of calcium carbonate. On the Ps film, large amount of calcite and aragonite can be observed. SEM of the gold surface shows aragonite needles and vaterite. On the glass surface, large amount of vaterite can be observed. Ps films self-assembled by different diameters of polystyrene spheres have different morphologies and surface roughness, which have deep effects on the crystal form of calcium carbonate.This simple route might open opportunity to synthesis and the study of other novel inorganic materials.
Application of HYDROX to Torpedo Thermal Power System
Authors: Shan Xiao Liang , Zhao Jun , Zhu Rui , Kong Yan Feng
Published: October 2011

HYDROX is a new kind of torpedo energy. According to its application possibility to thermal power torpedo, the application patterns, supply of constituent element of the energy, adjustment of power system are discussed in the paper. By the conclusion that the paper comes to, it is clear that the using of HYDROX can increase torpedoes’ tactical and technical requirements, improve its concealment performance, reliability and maintainability, and the methods to supply hydrogen and oxygen are simple and feasible, and the security of hydrogen and oxygen can be well ensured, so HYDROX will have a great future. The method and system scheme mentioned in the paper contribute to the design of thermal power system.
The Simulation on the Power Train System of the Hybrid Horizontal Directional Driller
Authors: He Tao , Meng Li Xin , Liu Zhi Qiang
Published: October 2011

As technology and equipment improves, the horizontal directional driller was gradually accepted in the developed countries in the 1980s. With the rapid construction of urbanization, non-excavating technology is widely used in China. In this paper, a new kind of hybrid technology in the horizontal directional driller is presented. Taking HL518B as a prototype, a parallel hybrid system is designed .The control strategy of the hybrid horizontal directional driller is analyzed on the basis of the several operations in the working cycle. The control goal of whole system is to realize the torque demand of loading. Research is made on how to transform the single engine power into the hybrid power train, At same time the model of hybrid system is established and simulated. The simulation results show the hybrid system can effectively improve the horizontal directional driller fuel economy.
On the Application of Cultural Bionics to the Automobile Styling Design
Authors: Hou Min Feng , Fu Li Ming
Published: October 2011

In automobile styling design, importing the concept of cultural bionics is a continuation and development for bionics design. This thesis tends to explore design inspiration and design methods from the perspective of social and cultural bionics, national cultural bionics, traditional cultural bionics and other corporate cultural bionics, so as to provide a fresh and workable cultural bionics method for the automobile styling design.
The Repairing of Camshaft Based on Surfacing Welding and Brush Plating
Authors: Meng Li Xin , Zhang Xi
Published: October 2011

The surfacing welding and brush plating are the commonly repairing technology when the components are wear or local damaged. Surfacing welding is to use the fusion of welding material and base material to repair the surface defect. Surfacing welding is used to repair the working size of camshaft commonly, otherwise, the cam is scrap and replace the new one Brush plating has good adaptability and flexibility in repairing components’ surface abrasion, and this method is convenient and fast. The combination of the two methods will not only bring better repairing effect in repairing the components, but also has good economy. Take the comprehensive repair in the engine’s camshaft for example in this paper, process of the combination in repairing is described detailed.
Reverse Kinemics of Bionic 6-RSS Chewing Robot for Food Mechanical Properties Measuring
Authors: Yu Jing Hu , Pei Gang , Zhang Yin Zhi
Published: October 2011

A bionic chewing robot was designed to measure the mechanical properties of food, and the measuring mechanical properties of food include hardness, viscosity, elastic and chewiness. The bionic robot was composed of six mechanisms, each mechanism include there kinematic pairs, namely, revolute joint, sphere joint, sphere joint. This paper introduces the chewing robot mechanism aim to simulate the function of mandible of real mankind, and established the equation of reverse kinemics of chewing robot according to the structure of the chewing robot. Through the simulation module of NX, the equation of reverse kinemics of chewing robot was simulated.
Research on Object Recognition of Intelligent Robot Base on Binocular Vision
Authors: Wang Jun , Mei Tao , Kong Bin , Dong Xiang
Published: October 2011

For intelligent robots need reliable object recognition and precise orientation in complex environments, this paper presents a method that use binocular vision to object recognition. In this paper, use least-squares fitting method to accurately determine coordinates of one matching point and four boundary points. calculate the three-dimension coordinate of the mathcing point via binocular vision theory, compute the three-dimension information include the size and height of the object via projection theory and restrictive relation between four boundary points and depth of mathcing point, which improve the reliability of object recognition and precise of orientation. The results of experiment show that this method can get reliable object recognition and precise orientation, meet the needs of robot path planning and grab objects with gripper.
Bond Graph Simulation and Test on the Working Hydraulic System of ZL50 Type Loader
Authors: Wang Hui , Yang Fei
Published: October 2011

Based on the modeling and simulation software 20-sim developed by Control Engineering Group in University of Twebte in the Netherlands, the bond graph model of the hydraulic system for the working device of ZL50 wheel loader was established. During simulating the model, with the main parameters of the model were set based on the actual test result, which can skip deriving state function and simulate the system directly with the results of pressure response. The simulation results show that this method is feasible and convenience in the application of hydraulic dynamic simulation. Further more, through the test of cylinder pressure when the loader in the practical work, by comparing with the simulation results, which provides a new way in the field of dynamic modeling and simulation for hydraulic system.
Study on Modal Analysis and Dynamic Performance of Electric Wheel Self-Dumping Truck Carriage
Authors: Li Xiao Huo , Cao Jiang Wei , Liu Shu Ming , Wang Chao
Published: October 2011

In view of the reality that the transport efficiency affected directly by fatigue failures on a carriage of a electric wheel self-dumping truck in running process, in order to inquiry the failure reason and study the relationship between the dynamic performance of the carriage and the natural frequency of the carriage, ANSYS finite software was used to analysis the dump truck carriage model created by PRO/E in the paper, the low-level frequency and the vibration of the dump truck carriage were obtained, and the carriage’s dynamic performance was studied with the verification principle of reducing the amplitude of frequency response function in resonance. The results show that the road surface excitation greatly affects the dynamic performance on the compartment floor, and the road surface excitation, which should be avoided, is the main reason of fatigue failure on the carriage.
Back Analysis of the Elastic Modulus and Horizontal Crustal Stress of Tunnel Surrounding Rock with System Identification Method
Authors: Zhou Hai Bo , Li Rui Duo
Published: October 2011

Cording to the measured data from the Fenshuiling tunnel of Lingnan freeway, the elastic modulus of tunnel surrounding rock and the horizontal crustal stress are back calculated with the system identification method. The results indicate that it is reasonable and the inversion procedure has stronger adaptive control,good convergent calculation stability,rapid calculation velocity. It shows that the system identification method to back calculate the elastic modulus of tunnel surrounding rock is effective.
Electro Hydraulic Control Harmonic Aging Stress Elimination Devices-Modeling and Simulation of the Hydraulic Vibrator with the Frequency Modulation Rotary Valve
Authors: Wang Hui , Li Meng
Published: October 2011

The main research is the working conditions of the hydraulic vibrator with the frequency modulation rotary valve. Use the hydraulic vibration technology knowledge to set up a hydraulic system model and then use AMESim to establish and analyze the simulation model. So the working curves of dynamic characteristic were gotten. It is useful to analyze the parameters for production and application of the aging stress elimination devices. AMESim is abbreviation of Advanced Modeling Environment for Simulation of engineering systems. AMESim offers a complete platform for systems engineering design, allows users on a single platform to create systems models of complex multi-disciplinary field, so to make simulation and in-depth analysis. On AMESim platform, users can research steady-state and dynamic performance of any component or system.
Study on the Hydrostatic Support of Internal Gear Pumps Based on FLUENT
Authors: Mao Jun , Liu Shuang , Zu Zhen Ni
Published: October 2011

A kind of hydrostatic support method was developed based on the analysis of the failure of internal gear pumps’ agglutination in this paper. The changing cycle of pressure on the internal gear was analyzed, and the grid model was built. The distribution of pressure on the inner wall of internal gear in different positions was simulated as well as the direction and magnitude by the FLUENT software. The angle range of the hydrostatic support’s channel on the inner wall of pump body was determined according to the above analysis and the force generated after making hydrostatic support’s channel was compared with the one of no hydrostatic support’s channel. The result of the numerical simulation and prototype experiment shows that the agglutination failure of inner mesh gear pumps can be avoided by hydrostatic support method.
A New Adaptive CFAR Detector
Authors: Xu Congan , Jian Tao , He You , Gu Xin Feng
Published: October 2011

A new CFAR detector based on Grubbs statistic called G-CFAR detector is proposed and its detection architecture is given.in this paper. Also the values of the threshold in different confidence level are given. The G-CFAR is evaluated through Monte-Carlo simulation in various environments. In homogeneous background, the performance of G-CFAR shows a little worse than that of CA-CFAR. In multiple targets background, the G-CFAR performs robustly, especially when the interfering targets are not confined to a single half of the reference window, the G-CFAR keeps good performance, while the VI-CFAR can not detect the targets effectively .
Study on a Control Method Used in the Semi-Active Suspension
Authors: Zhao Yun Tang , Chen Si Zhong , Feng Zhan Zong
Published: October 2011

A new control method used in the semi-active suspension is studied. The force generated by the semi-active damper can be divided into two parts, one is the uncontrollable force, and the other is the controllable force. In order to make the sprung mass have the ideal isolation effect, the controllable force should be equal to the sum of the uncontrollable force and the force generated by the suspension spring. But the controllable force is limited by many constraints. Therefore, the control strategy can be concluded. The simulation results show that the ride comfort and handling stability are both improved by the control method.
Target Tracking Approximation Algorithms Based on Particle Filters and near-Linear Curve Simplified Optimization in WSN
Authors: Gao Xiang , Yang Yin Tang , Zhou Duan , Zhang Jian Xian , Chai Chang Chun
Published: October 2011

In order to process target tracking approximation with unknown motion state models beforehand in a two-dimensional field of binary proximity sensors, the algorithms based on cost functions of particle filters and near-linear curve simple optimization are proposed in this paper. Through moving target across detecting intersecting fields of sensors sequentially, cost functions are introduced to solve target tracking approximation and velocity estimation which is not similar to traditional particle filters that rely on probabilistic assumptions about the motion states. Then a near-linear curve geometric approach is used to simplify and easily describe target trajectories that are below a certain error measure. The validity of our algorithms is demonstrated through simulation results.
The FPGA Implementation of NLMS Adaptive Interference Cancellation Algorithm
Authors: Dai Jing , Zhang Guo Lin , Zhao Kun
Published: October 2011

A adaptive interference cancellation algorithm was proposed in this paper，which was based on NLMS algorithm.The NLMS algorithm was achieved on FPGA chips. This paper described the method of the specific implementation. This method introduces bit-shift in terms of subsection instead of division operation, by which the operation speed of FPGA is improved apparently.By Matlab simulating the functions, and analyzing the PSD curve and the constellation of output signals, the adaptive interference cancellation algorithm system based on NLMS achieved expected effect. The better in-band flatness of the PSD curve and the higher convergence rate on constellation were obtained. Therefore, the NLMS adaptive interference cancellation algorithm is chosen as the design with High Performance-price Ratio.
Application of Knowledge Based Engineering in Building Mould Standard Components
Authors: Huang Hong Hui , Wang Ling Yun
Published: October 2011

It analyzed the substance of parametric design. Nowadays, the CAD technology can not express the product knowledge and design experience. The combination of knowledge-based engineering (KBE) and CAD solved these problem in the filed of molding. UG/KF is a new technology to integrate CAD and KBE. This paper develops the mould parts with UG/KF as an example to explain its application, and point out the developing direction of CAD by analyzing new characteristics of knowledge fusion.
Development and Validation of Offset Deformable Barrier Model with Beam Element
Authors: Cao Li Bo , Cheng Wen Tao , Shi Xiang Nan , Chen Jie , Quan Li
Published: October 2011

According to GB/T 20913-2007 regulation, the finite element model of the offset deformable barrier (ODB) was built with beam and shell elements, and validated in the simulation of quasi-static compression test. In order to analyze the local deformation characteristics of the ODB model, a sled test was designed. A cylinder impactor of 110 mm in diameter was welded in front of the sled. It was used to impact the fixed ODB. The simulation model of this test was also built. The acceleration of the sled and the deformation of the ODB were measured in the test and compared with the simulation data. The results show that the ODB model with beam elements not only satisfies the demands of the regulations, but also has good local deformation characteristics. The efficiency of computing can be improved obviously with beam elements.
Development of Configuration Software Interface for Engineering Vehicle Supervisory Control and Management
Authors: Yuan Hai Bin , Xiang Hui Feng
Published: October 2011

The design and development of embedded configuration software is becoming one of the most important issues, the aim is to achieve mission-specific tasks and integrate supervisory management and control function in a collaborative way. In order to deal with the design and development of configure software for heavy-duty vehicle, object-oriented programming method is employed. At the same time, graphic-based display is realized using class object conception, and double buffering mechanism is proposed to improve graph display performance, furthermore, XML based serialization is employed to store the graph repository. The development environment and entire design process are based on the c sharp platform to take advantages of compatibility and scalability as well as meet further improvement. A snapshot of the graphic interface realization is shown to validate the design method.
Study on the Date Generation Process of Chinese Thermal Power
Authors: Chen Han Li , Qin Tao
Published: October 2011

In China, the thermal power is the main structure of power source. We consider that analysis thermal power’s date generation process is very important to precise planning of thermal power and whole electricity market. For testing the impact of inspection and external factors on thermal power, we study date generation process of thermal power by structural change model that carry unit root test and trend stationary test. This conclusion indicates that thermal power’s date generation process is the unit root process of structure change and isn’t trending stationary process.
The Model and Simulation of Hydraulic Non-Sinusoidal Vibration System on Billet Caster Crystallizer
Authors: He Xue Wen , Wang Yun , Tang Qing Bo , Jia Xiang Bao
Published: October 2011

Study focusing on the dynamics of the crystallizer hydraulic non-sinusoidal vibration system in the bullet caster crystallizer, which is employed in an electric furnace factory, is introduced. With respect to construct a mathematical model of continuous casting crystallizer hydraulic vibration system, a power band graph method is applied. With the utilization of this method, a process of modeling and evaluating the performance of the hydraulic cylinder, electric-hydraulic servo and sensor system is conducted. The system is also analyzed and simulated by MATLAB/SIMULINK. In our experiment, the performance of the crystallizer non-sinusoidal vibration system with the change of main parameters is studied. Furthermore, an experiment is also conducted aims at investigating the quality requirements for the servo system, including stability, rapidity, and accuracy. Furthermore, an experiment is also conducted aims at investigating the quality requirements for the servo system, including stability, rapidity, and accuracy. The results demonstrate that crystallizer hydraulic servo non-sinusoidal vibration system can satisfy high frequency steel ball requirements and small amplitude design requirements. In addition, it can effectively improve the surface quality of casting blank.
The Simulation Analysis of Structure Type Effect on Cutting Process
Authors: Li Shu Jun , Wan Xiao Hang , Dong Zhao Wei , Yuan Yuan
Published: October 2011

Based on the plastic-elastic method, the 3-D milling FEM analysis model is established in this paper, which simulates the material removal process. This paper studies the release of initial residual stress how to affect the deformation in different structure parts. Compared with the results of simulation and experiment, it can be drawn a conclusion that the symmetric release of the residual stress facilitates to reduce the machining deformation.
Wood Board Defects Sorting Based on Method of Possibilistic C-Means Improved Support Vector Data Description
Authors: Zhang Yi Zhuo , Tong Chuan , Yu Hui Ling , Cao Jun
Published: October 2011

This paper exposes automatic classification for wooden board according to its knot defects. A four-parameter-classification vector, which includes the knot size and red component pixels of interior and exterior and boundary part of the knot, is formed to recognize the knot type. A possibilistic c-means (PCM) improved support vector data description (SVDD) method was proposed to construct a multi-classifier to classify four types of wood knots. The results obtained with our method show a real improvement of the recognition rate, which is 94%, compared to the original SVDD classifier, which recognition rate is just 86%, and experiments also testify PCM can help SVDD overcome the shortage of being sensitive to the noises and outliers.
Face Detection Method Based on SSR Algorithm
Authors: Song Kai , Wang Lei , Liu Zhi Kun
Published: October 2011

In order to achieve high speed and high reliability of face detection system, a feature-based template-matching algorithm to detect a key part between the two eyes used. The method is achieved through divided a filter into six rectangular. The face detection process adopts the “integral image” theory. Just calculating the information of around the eyes, eyebrows, and nose area, aspect ratio of the value of the SSR filter is set to 2.22:1 through the experimental which improved the SSR algorithm. Using the advantages of gray-level information, it has better reliability on the changes in light conditions. The experiment result shows that the accuracy rate of the standard frontal face detection is 95%; to monitoring images, the accuracy rate of the “eyes - human face” window location detection is 90%
Finite Element Analysis of Impact Plunger and Drill Rod and Optimization Design for Drill Rod of YC70 Hydraulic Impactor
Authors: Yang Guo Ping , Zhu Fa Long , Yin Wen Long , Cheng Yi
Published: October 2011

This paper is primarily focused on finite element analysis and topological optimization of impact plunger and drill rod. Finite element method is an extremely functional, due to which we apply ANSYS software to analyze the stress and strain that impact plunger and drill rod bear in actual working condition and optimize their structure.
Software Design for Centralized Monitor of Chang’E-1 Operational Simulator
Authors: Zheng Ai Wu , Zhou Jian Ping , Ma Yong Ping , Ga Yu Hui
Published: October 2011

Operational simulator is a simulated training system used in a flight control center to train and improve mission operators’ ability to control and track spacecrafts, constructing a realistic mission-like circumstance for the system drilling. But previous simulator had not a centralized monitor. It must be operated and monitored at different terminals. Usually several operators are required to operate at the same time with a demanded order. It is very inconvenient to use. So, the centralized monitor software is specially designed for Chang’E-1 operational simulator. It is used for operations, status setting, Data management and monitors of the simulator. This paper introduces functional requirements, network structure, and design scheme of modules of the software. The object-oriented programming of plug-ins is adopted in the program development. The practice proves that it is very convenient for a single user to operate the Chang’E-1 operational simulator by using the centralized monitor software, and it also saves manpower and cut expense. The software architecture can be applied in centralized monitor software of future simulators.
Face Recognition Method Based on the Fuzzy Neural Network
Authors: Pan Xiang
Published: October 2011

This paper discusses a face recognition method based on the fuzzy neural network (FNN). The fuzzy neural network has more advantages than artificial neural network alone. The paper firstly introduces the structure of the FNN. Than proposed the fuzzy rules and the study algorithm. Thirdly it researches on the process of face recognition. The experimental results prove that this method can achieve good location performance and good effect of extraction.
High Accuracy Algorithm of Airborne Interferometric Synthetic Aperture Radar
Authors: Han Song Tao , Tang Ge Shi , Mao Yong Fei , Chen Lue , Wang Mei
Published: October 2011

Interferometric Synthetic Aperture Radar is one of the most important technologies for topographic mapping. The DEM quality of airborne InSAR system depends on both system hardware performance and data processing methods. To derive large scale topographic and thematic maps up to scale 1:50000 and 1:10000, the whole data processing methods were presented. The methods included SAR imaging, interferometric processing and cartographic processing. Special methods were induced to resolve the problems encountered in project applications. Results using X-band airborne InSAR system data showed validity of the algorithm.
Design of a Sliding Mode Control with a Nonlinear Continuous Time-Varying Switching Surface
Authors: Li Guang , Liu Ling Hua
Published: October 2011

A new sliding mode controller design approach for second-order systems is proposed that varies the switching surface in a nonlinear continuous time-varying fashion. The sliding mode control system, which the slope and intercept of switching surface changes continuously, can improve the system performance in terms of a eliminating in the reaching time process, robustness to parameters uncertainties and disturbance. The computer simulation results show the validity of the method.
Dynamic Properties on Double Driving Articulated in-Pipe Robot Inspecting System
Authors: Chen Jun , Chen Tao , Deng Zong Quan
Published: October 2011

To solve the problem of increased resistance founded in prototype test for single traction articulated in-pipe robot inspecting system move inversely, a driving scheme with double driving in-pipe robots located in both ends of inspecting system has been put forward. For the deflection of hinge connection caused by the misaligned centroid position of each modular unit, the limited contact mechanics model between the modular unit and pipe wall is established, and the stability of movement of modular units moved in elbow pipe is analyzed by example. The simulation results verify the rationality of analysis process, to provide the basis for improving in-pipe robot inspecting system design.
Intelligent Information System Design on Water Quality Monitoring, Water Bloom Prediction and Emergency Treatment Decision-Making
Authors: Chen Chen , Wang Xiao Yi , Liu Zai Wen , Zhao Zhi Yao , Wang Xiao Kai
Published: October 2011

According to the urgent requirement of water quality monitoring, water bloom prediction and emergency treatment decision-making, a multi-functional information system based on GIS (Geographic Information System) is designed and developed, which integrates water quality monitoring and analysis, water bloom prediction and emergency treatment decision-making. VS2010 platform and SQL Server 2005 database are used in the system, and the remote data communication is realized by GPRS. The system has functions such as lakes and reservoirs’ water quality real-time monitoring, teletransmission and location, water quality data analysis, water bloom prediction and emergency treatment decision-making. The medium-term prediction of water bloom is realized by wavelet neural network, and the optimal choice of water bloom emergency treatment decision-making projects is realized by multi-attribute decision-making theory. This design offers effective decision-making system for environmental protection departments, which also has significant meaning to the protection and renovation of water environment, and its application and promotion have considerable social and economic benefits.
Method of Parallel Active Power Filter Compensation on 3-Phase 3-Wire Nonlinear Unbalanced Load System
Authors: Zou Wen Xue , Liu Sheng Hui
Published: October 2011

The parallel active power filter has been accepted by users because of its’ installing and removing without disturbing other users and so its’ detecting and controlling algorithms have been studied with large efforts .A method about direction of active power flow (DAPF ) was raised in present paper under condition of the 3-phase asymmetrical voltage and 3-wire nonlinear unbalanced load. It’s means that detected currents on the point of common coupling can be put into two parts according the active power flow direction ,one of which is called positive direction current and another is called negative direction current .then decompose the asymmetrical voltage and positive directional current with Symmetrical Component Method. We can obtain the reference current components with clear physical meaning for the paralleled active power filter .The method shows there are several harmful power components could not be eliminated with parallel active power filter.
Monitoring of Winding Deformation of Power Transformer by Using Nanosecond Pulses
Authors: Liu Hua Lin , Zhan Yin Bo , Lei Xiao , Wang You Yuan , Zeng Hua Rong , Li Jian
Published: October 2011

As we know, the TF method is more sensitive to changes in the power transformers at higher frequencies. Although measurement based on low voltage impulse (LVI) is definitely faster than that based on swept frequency method (SFM), the available frequency band is narrow because of the typical microsecond impulse. In this paper, the characteristics of the nanosecond impulse in the frequency domain were investigated. A test System based on Nanosecond low voltage impulse was developed. The proposed method was applied to a 10kV/100kVA distribution transformer in the laboratory. Measurement results with two different impulses were compared.
Requirements of Level Arm Measurement Precision in Airborne Gravity
Authors: Huang Yang Ming , Zhang Kai Dong , Cai Shao Kun , Wu Mei Ping
Published: October 2011

Accelerometer bias and gyro drift determines the long term precision of the strapdown inertial navigation system (SINS) which is the primary and critical component of the strapdown airborne gravimeter (SAG). Making use of the complementary characteristic of DGPS and SINS has been widely and successfully used in many practical applications to prohibit the long term drift on condition that they are consistent in time and space, which stands for time synchronization and lever arm effect respectively. The paper extends kalman filter with lever arm as one of its states and gives the observability analysis in a global perspective. Observability shows that at least two segments of the trajectory with linearly independent angle rate make the lever arm observable. Simulation demonstrates that 10 centimeters error in three quantities of the lever arm vector has an impact at the level of 3 mGal in the horizontal accelerometer bias but little effect on the vertical quantity. Different simulations prove the analysis and highlight the pitch maneuvers during the climbing of the flight test and emphasize the importance of the angle rate to the estimation of the lever arm rather the magnitude of the angle itself.
Robotic Waist Mechanism Driven by Dielectric Elastomer Actuators
Authors: Guo Shuai , Wang Zhi Yong , Li Jian , Shi Wei
Published: October 2011

This paper presented a waist mechanism driven by dielectric elastomer actuators (DEA), suitable for a small light robot. Unlike traditionally continuous range-of-motion actuators, DEA have only two discrete states, both of which are stable. As a result, waist mechanism has a finite number of states, but works like human waist and just need 36 switching values to control. Major benefits of the waist mechanism are that extensive feedback control is not required, task repeatability can be very high, and DEA are very inexpensive, thus resulting in low cost robots. The waist mechanism is attractive but needs further investigation before successful application.
Selection and Optimization in Vibration Isolation Structure of Marine Podded SSP Propulsion
Authors: Zhang Gui Chen , Pang Huan Dong , He Ji Qing
Published: October 2011

Vibration isolation structure of Siemens-Schottel-Propulsor (SSP) is analyzed and the parameters and optimization in vibration isolation structure is computed theoretically in this paper. The choice of parameters in vibration isolation structure is an optimization process, and it is subjected to many practical constraints. From the view of the force strength, the vibration isolation materials should be “hard” while from vibration reducing effect it should be “soft”. For the double-layer vibration reducing structure, in addition to meeting the requirement of deformation and strength, the obvious stiff difference should be arranged in structure to reduce vibration. The vibration isolation structure plays the role as a transfer functions, outputs different responses according to different excitation input. The results show that the characteristics of the exciting signals should be considered in the SSP vibration isolation structure’s design, it is important to select the vibration isolation for SSP cushion materials.
A Self-Calibration Algorithm for Concentric-UCA in the Presence of Mutual Coupling
Authors: Chen Hui , Wu Yao , Zhao Man
Published: October 2011

A self-calibration algorithm for concentric uniform circular arrays (C-UCA) in the presence of mutual coupling is presented. The proposed algorithm can simultaneously estimate the directions of arrival (DOA) of signal sources and coupling coefficients of antenna array with a calibration source. It not only can calibrate the mutual coupling of the inner sub-arrays, but also can compensate for the mutual coupling between sub-arrays. Compared with conventional self-calibration algorithm based on iterative alternating minimization technique, the proposed algorithm transforms joint estimation about DOA and mutual coupling coefficients into cascaded estimation, which means that the parameters can be obtained by one dimensional spectrum peak search. The proposed self-calibration algorithm has high estimation precision and low computational burden. Simulation results show the effectiveness of the presented method.
Study on Data Acquisition and Measurement System of Occupant Restraint Test Bed
Authors: Bai Zhong Hao , Xu Zheng , Yan Qiang , Zhang Qian Bin
Published: October 2011

A new occupant restraint system test bed was designed based on the regulations on automotive seat test and safe-belt contact point strength test, which was capable of conducting seat rigid test, safe-belt contact point strength test, headrest performance test. The structure and parameters of the test bed were designed and FE model of the centre frame of the test bed was built with ANSYS to analyze the strength. Then the measuring and control system was developed based on LabVIEW. Finally, the static strength test of automotive seat and safe-belt contact point test were performed to evaluate the test device. The results demonstrated that this device met the test regulation requirements and could be used to conduct further investigation and vehicle design for occupant restraint system.
Study on Electromagnetic Exciting Force Characteristics and Electromagnetic Noise of Permanent Magnet DC Motor
Authors: Liu Man Lan , Yu Tian Da , Cui Shu Mei , He David
Published: October 2011

Electromagnetic exciting force is the key to generate electromagnetic noise. The characteristics of electromagnetic exciting force and the causing of electromagnetic noise were analyzed after the power was off for cooling fan Permanent Magnet DC (PMDC) motor. Time-stepping finite element method was selected to calculate its several parameters, such as air gap magnetic density harmonics generated by the stator and rotor, torque ripple and unbalanced magnetic pull at its different speed.Experiment on unloading vibration noise was carried out to confirm the validity of electromagnetic exciting force analysis. The results show: electromagnetic force amplitude keeps constant while the motor speed changing. Torque ripple decreases while the motor speed down. A kind of electromagnetic noise called howling noise produced by PMDC motor used in car cooling fan is mainly due to resonance. So the best way to eliminate this motor’s noise is to improve the order of electromagnetic waves and avoid the electromagnetic resonance.
Preparation and Characterization of Molecular Imprinted Polymers of Tetracycline Antibiotics by Mixed-Templates
Authors: Gong Guo Li , Jia Lin , Li Hui , Qi Xiang Jun
Published: October 2011

Molecular imprinted polymers (MIPs) were synthesized in certain conditions in the experiment when tetracycline antibiotics (TCs), including Oxytetracycline, Chlortetracycline and Tetracycline were used as templates, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker. Oxytetracycline and Chlortetracycline (1:1) were chosen as mixed-templates when the bonding property of the polymer was studied. The results showed that the mixed-templates MIPs had high selection for tetracycline, and were expected to be used as separation materials for the extraction and purification of TCs in animal food.
Research on Molten Iron Vertical Flow Rate and Level Based on Dynamic Infrared Radiation and Time Intervals
Authors: Liu Chen Xi , Jin Wei , Liu Jun Jie
Published: October 2011

In the foundry, it's difficult to measure the level of molten iron in pouring package and the flow of molten iron each pouring during casting control process, which will result in the control problem of over-pouring and under-pouring.So,a new measurement method about molten iron level and dynamic detection of vertical flow rate has been developed in this paper.The method is based on infrared radiation and time intervals under the state of vertical flow rate of molten iron. By analysing the flow rate of molten iron in the casting ladle taphole theoretically, building field experimental device and analysing experimental results, it shows that the proposed iron level measurement and dynamic detection of vertical flow rate based on infrared radiation and time intervals are feasible. And then it lays a foundation for controlling the flow of molten iron.
A Cellular Intrusion Detection Framework for Packet Dropping Attacks in Wireless Sensor Networks
Authors: Tong Xin , Chen Lan , Li Ying
Published: October 2011

Wireless sensor networks (WSNs) are vulnerable to a variety of malicious attacks, especially the packet dropping attack, making security an important research field. Since prevention based techniques are less helpful for guarding against inside attacks, intrusion detection (ID) techniques are indispensable to provide advanced protection. This paper proposes an innovative cellular ID framework for packet dropping attack, which takes the deployment of passive listening nodes into consideration. Performance evaluation made in VisualSense demonstrates its high detection accuracy.
A New Method Based on HMMs and K-Means Algorithms for Noise-Robust Voice Activity Detector
Authors: Luo Bing , Pei Zheng , Xu Li , Hu Da Li
Published: October 2011

In this paper, we proposed left-right hidden Markov models (HMMs) combination with k-means threshold of Likelihood ratio test (LRT) to identify the start and end of the speech. This method builds two models of non-speech and speech but not two states, i.e. each model could conclude several states. In the experiments we present the Voice Activity Detection (VAD) results between two states hidden semi-Markov model (HSMM) and proposed algorithm. We also compare accuracy and robust between the k-means threshold and the adaptive threshold in high signal to noise rate in the background noise. It presents that k-means threshold is more effective than the adaptive threshold and the proposed method also make a better performance than two states HSMM based VAD, especially in the low signal-to-noise ratio (SNR) environment.
A Novel Method for Measuring the Open-Circuit Loss and Short–Circuit Loss of Distribution Transformers Online
Authors: Li Xia , Chen Min You , Cheng Shan
Published: October 2011

The paper proposes a novel method for online measuring the open-circuit loss (OCL) and the short-circuit loss (SCL) of distribution transformer DT, based on the consideration of the drawbacks of the offline measuring method, which is regarded as the mainly and traditionally used methods for measuring the OCL and the SCL of DT. The novel method avoids the drawbacks of the offline method which is not cost-effective and is not good for the reliability of the power supply. Firstly, the relation expression of the short-circuit impedance with respect to the voltage and current of the primary and secondary side is developed from the analysis of the equivalent circuit model of DT, and the relations between the SCL and OCL and the short-circuit impedance are also deduced according to power balance. Then, the online short-circuit impedance is computed by using linear regression technique and the value of online voltage and current of DT. Furthermore, according to the developed relations, the online OCL and the SCL of DT can be acquired by using the obtained short-circuit impedance. Numerical simulations have been carried out on Matlab/smulink and results verified feasibility and effectiveness of the novel method for online measuring the OCL and the SCL of DT.
A Novel Precision Strain Measuring Circuit with Double-Channel Method
Authors: Cao Jun , Zhang Na , Zhang Jia Wei , Li Ming Bao , Zhang Xiu Mei
Published: October 2011

To improve the accuracy of strain, the design method and technology based on the theory of double-channel parametric measurement is proposed. At last, the measuring circuit with linear conversion function is designed. Based on the theory, a measuring system is developed. The practical experimentation indicates that the theory and technology are right, and the accuracy, stability, anti-interference and reliability are excellent.
A Simplified Cascaded Modular Structure for the Implementation of MVDR Detector
Authors: Li Zhong Jie , Zhu Cui Tao , Chen Shao Ping
Published: October 2011

A cascaded modular structure is proposed to implement the blind MVDR detector. In each module of the structure, a vector filter is introduced for adaptive interference cancellation. The weight vector is determined based on a maximum magnitude cross correlation criterion which maximizes the magnitude of the cross correlation between the output of the nonadaptive filter and that of the weight vector filter. The performance of the proposed receiver has been evaluated via computer simulation and shown to be comparable to that of the optimum method under asymptotic condition. When the number of received vectors is non-ideal, the proposed method outperform the optimum method.
A Skew Detection Algorithm for PDF417 Based on Feature Point
Authors: Li Jian Hua , Li Ping , Li Xiao Dan , Wang Yi Wen
Published: October 2011

The automatic identification of 2D (two dimensional) bar code PDF417 is very sensitive to skew angle, but, the common skew angle detection methods have shortcomings such as weak performance in time complexity. In this paper, based on the properties of PDF417 character code and the extraction of feature points, we get skew angle of PDF417 bar code image using the least square method. Experiments show that this algorithm has virtue of less computation and high accuracy.