Volume 37,Issue 4,2014 Table of Contents

1 Infulence of individual pitch control on the load of large-scale wind turbine

JIN Xin , JU Wenbin , HE Yulin , DU Jing , YANG Xiangang

2014, 37(4):1-7. DOI: 10.11835/j.issn.1000-582X.2014.04.001

[Abstract](2093) [HTML](498) [PDF 8.97 M](1271)

Abstract:
A thorough study on large-scale wind turbine is presented，and the force and torque(flap wise and edge wise) are derived from wind inflow velocity based on BEM theory. Through the Coleman transformation, a system state space equation is established. Based on the equation，the theory research on individual pitch control is studied and programmed in MATLAB/SIMULINK. The theory research and engineering application show the superiority of individual pitch control design on load reduction，which is more suitable for the control of large-scale wind turbine. Individual pitch control can reduce the load that is happened in the operation process，so as to extend system service life and decrease maintenance.

2 Experiments on transmission efficiency of electric drive AMT shifting actuator

ZHANG Zhigang , GE Shuaishuai , HAO Jianjun , SHI Xiaohui

2014, 37(4):8-13. DOI: 10.11835/j.issn.1000-582X.2014.04.002

[Abstract](1779) [HTML](432) [PDF 5.66 M](1071)

Abstract:
In order to analyze efficiency of electric-drive AMT shifting actuator from experimental perspective and form an effective test evaluation system，an average transmission efficiency test program is designed through analyzing features of electric-drive AMT shifting actuator. According to the motion law of electric-drive AMT shifting actuator，a new computing method of the average transmission efficiency is proposed. Based on the AMT actuator test bed，the average transmission efficiency of an AMT shifting actuator is respectively tested in two working conditions with time-constant load-variable and with time-variable load-constant. Results indicate that the average transmission efficiency on the basis of the test program and computing method have a good repeatability；and when the test time is constant，the average transmission efficiency increases along with the load；however，when the load is constant，different test time has little effect on the average transmission efficiency.

3 Hierarchical modeling and control of four-wheel-independent-vibrationabsorbing vehicle

WU Long

2014, 37(4):14-22. DOI: 10.11835/j.issn.1000-582X.2014.04.003

[Abstract](1346) [HTML](298) [PDF 9.41 M](986)

Abstract:
By considering the vertical road roughness and accompanied lateral excitaion produced by tire effect，a traditional vehicle model with fourteen degrees of freedoms is adopted as background. Based on the space force analysis on sprung mass of the full vehicle，five body motions such as vertical，lateral，pitch，roll and yaw vibrations are studied，and ratio relations of coupling dynamics between a whole vehicle and each four quarter vehicles of vertical and lateral directions are deduced. A hierarchical parallel model which contains some independent quarter vehicles is formed. A concept of four-wheel-independent-vibrationabsorbing(4WIV) vehicle is proposed. The central level is founded by above coupling ratio relations and local control levels are constructed by quarter vehicles. Based on sophisticated robust control strategies under Matlab software environment，the control process of 4WIV vehicle is simulated. The results show that the system response could be quickened and ride comfort and handling properties would be improved due to parallel computation realization of local control parameters. The research on 4WIV vehicle in this paper lays the theoretical foundation for its application in automotive fields.

4 Analysis of operating characteristics of dual stator-winding wind power induction generator

HAN Li , LUO Zhangyao , JIN Zhao , YUAN Chun , LU Bin , SU Hongchun

2014, 37(4):23-32. DOI: 10.11835/j.issn.1000-582X.2014.04.004

[Abstract](1600) [HTML](297) [PDF 9.51 M](1040)

Abstract:
To research the operating characteristics of dual stator-winding induction generator(DWIG) in wind power generation system，the operating mechanism and features of DWIG with the speed change as well as the load change are analyzed based on the equivalent circuit and phasor diagram. And then，the calculation methods of control winding current with different loads are derived. Furthermore，aiming at the rated and variable speed operation modes，the operating characteristics of a 18.5 kW DWIG with inductive load are analyzed in detail. The results show that the control winding can regulate the excitation reactive power to build up the no-load voltage. With the increase of the load current，the control winding current and the slip ration increase，and the efficiency increases first and then decreases. The control winding can regulate the reactive power in variable speed condition for constant voltage output. The correctness of the research is verified by the consistency of the theoretical analysis and the simulation results.

5 Research on prognostics and health management system of frequency convector

YANG Xinyu , MA Qishuang , ZHANG Lin , ZHANG Qiang

2014, 37(4):33-38. DOI: 10.11835/j.issn.1000-582X.2014.04.005

[Abstract](1759) [HTML](712) [PDF 6.61 M](1082)

Abstract:
To meet the requirement of high reliability and indemnificatory to power supply system of certain weapon system，the general structure of prognostics and health management(PHM) of frequency converter system based on its fault mechanism is presented，the function of every layer in PHM of frequency converter system is explored，and the key technology of PHM system is studied. By considering the rapid calculation requirement, PHM and database of maintenance based on industry personal computer are designed. Intelligent diagnosis algorithm and effective fault prognostics based on the Hilbert transform technology are proposed. The correctness and validity of the structure of PHM of frequency converter system are tested and verified though the experiments. The system fulfils the basic functions of prognostics and health management for frequency converter system. It provides an effective method of prognostics and protection for typical frequency converter system.

6 A method for mobile robot SLAM based on modified particle filter

ZHU Lei , FAN Jizhuang , ZHAO Jie , WU Xiaoguang

2014, 37(4):39-45. DOI: 10.11835/j.issn.1000-582X.2014.04.006

[Abstract](1661) [HTML](311) [PDF 6.42 M](1102)

Abstract:
Traditional methods based on particle filter for mobile robot SLAM(simultaneous localization and mapping)always induce particles degradation. Focusing on the particles degradation of the traditional particle filter and the need of a large number of particles to improve the precision of robot location，the AFAS(artificial fishing-swarm algorithm) is introduced into the particle filter method. This method updates the particle’s prediction again basing on the AFSA which adjusts the particle distribution concentrate around the robot’s true pose and improve the accuracy of SLAM. Through the MATLAB simulation，the results show that the method can locate the robot quickly and accurately，and improve the mapping precision.

7 Weighted sparse principal component analysis and it’s application

XUAN Shibin

2014, 37(4):46-51. DOI: 10.11835/j.issn.1000-582X.2014.04.007

[Abstract](1638) [HTML](987) [PDF 4.94 M](890)

Abstract:
The principal component analysis(PCA) is one of the important methods for feature extraction，but it can’t provided more classification information by itself. In order to pick up feature information in favor of recognition from PCA eigenvector，a weight sparse principal component analysis is proposed in the paper. It achieves image de-noising function by using primitive PCA algorithm，acquires the group of weight values which are able to maximize within-class distance and minimize between-class distance in PCA feature space by utilizing Lagrange multiplier，and finishes dimension reduction by using sparse PCA(SPCA) to retain effectively some classification information of eigenvectors with little eigenvalue. In the end，the proposed algorithm is tested on an all-known public face database. The experiment results indicate the proposed algorithm has not only faster running speed but also better rate of recognition.

8 Fusing LBP and HOG features by canonical correlation analysis for facial age estimation

QU Zhong , KONG Lingjun , FENG Xin

2014, 37(4):52-57. DOI: 10.11835/j.issn.1000-582X.2014.04.008

[Abstract](2120) [HTML](338) [PDF 7.54 M](1199)

Abstract:
Estimating human age via facial image analysis is very difficult，due to the fact that the factors of causing variations in the appearance of the human face include not only the aging，but also the lifestyle and life environments etc. Both illumination and position of facial image have side-effect on the age estimation. Existing estimation methods consider the shape or texture of facial image to characterize human aging with the preprocessing of the gray-balance and Procrustes analysis. Motivated by the fact that both LBP and HOG information of facial images are robust to control illumination and rotation and can provide complementary information in characterizing human age，we propose fusing these two sources of information at the feature level by using canonical correlation analysis(CCA) for enhanced facial age estimation. Then，we learn a multiple linear regression function to uncover the relation of the fused features and the ground-truth age values for age prediction. Experimental results are presented to demonstrate the efficacy of the proposed method.

9 Performance analysis on sorting algorithms in cloud computing environment

DING Yucheng , ZHUGE Qingfeng , SHA Xingmian

2014, 37(4):58-64. DOI: 10.11835/j.issn.1000-582X.2014.04.009

[Abstract](2499) [HTML](740) [PDF 8.40 M](1268)

Abstract:
With the rapid increase of data amount in cloud computing environment，it is an urgent need to study how to analysis and process those data fast and effectively. How to sort large scale data efficiently in cloud computing environment is a significant problem. Whether the widely used sorting algorithms can achieve high-performance and how many cloud computing resources they consume are concerned problems. This paper studies and implements several efficient sorting algorithms，including Radix sort，Quicksort and Sample sort，based on Hadoop，analyzes and compares the efficiency，consumption of CPU resources，memory consumption and communication between machines. Through a large number of experiments，it’s found that compared to Radix sort and Quicksort，Sample sort has the advantages of higher sorting speed，higher load balancing and lower CPU consumption. This result provides a valid basis and foundation for designing more efficient，energy-saving algorithms in cloud computing environment.

10 Delay measuring technique of BOC signal channel

CUI Xiaozhun , CHEN Yu , DONG Haiqing , WANG Qinghua , ZHU Jiantao

2014, 37(4):65-70. DOI: 10.11835/j.issn.1000-582X.2014.04.010

[Abstract](1474) [HTML](326) [PDF 5.84 M](946)

Abstract:
The delay caused by signal transmission channel of navigation satellite is a part of the total delay of the satellite-to-earth link，and it must be deducted in the actual positioning and timing applications. Delay measurement of satellite channels must be carried out in ground tests. Test accuracy of the channel delay will affect users ranging accuracy and precision time transfer. A BOC(binary offset carrier) signal channel delay measuring technique using partial correlation is proposed. BOC navigation signals and 1 PPS(1 pulse per second) signal are high-speed synchronous sampled. Partial correlation processing is made for the sampling BOC signal data and the integration time is less than a pseudo-random code cycle. The starting point of the pseudo-random code sampling data obtained by processing，then the transmission channel delay of the BOC navigation signals can be calculated. The uncertainty of the test method is less than 0.2 ns for sampling frequency of 10 GHz.

11 R&D on hydraulic rotary actuator based on virtual prototype technology

ZHAO Xianqiong , CHEN Zhihong , LIU Yilun

2014, 37(4):71-76. DOI: 10.11835/j.issn.1000-582X.2014.04.011

[Abstract](1492) [HTML](463) [PDF 6.52 M](1096)

Abstract:
Virtual prototype technology is a new method in R&D，which can effectively improve the product quality，decrease the new product developing time and reduce the production cost. A virtual prototype of rotary actuator is built up for simulation. According to double involute-spiral-pairs，which are the key parts of the hydraulic rotary actuator，a research is done on the relationship between input pressure and output torque. After simulation and experiment，it’s found that system pressure and output torque is in a positive linear programming. And another experiment is carried out on the relationship between different helix angles and output torques under same pressure. Through three series simulations within helix angles of 30°，45° and 60°，it’s found that we’d better design a helix gear in around 45° helix angle without any gear modification，so that we can get a optimized output torque. If a bigger output torque is wanted without higher pressure，the initial way is to increase the gear radial dimension.

12 Geometrical scale and density measuring system for nuclear fuel pellets

GAO Chao , ZHANG Sichao , JIN Lei , JIANG Cong , LIAO Bin , WANG Tao

2014, 37(4):77-81. DOI: 10.11835/j.issn.1000-582X.2014.04.012

[Abstract](1343) [HTML](451) [PDF 5.07 M](1031)

Abstract:
In view of the particularity and importance of pellets，a geometrical scale and density measuring system for nuclear fuel pellets is designed. The system realizes bi-dimensional，synchronous and high-precision measurement for pellets’ height and diameter by using optical noncontact way，and uses multi-point scanning for diameter due to the particular require of diameter measurement. Measuring pellets’ weight while finishing the measurement of geometrical scale，the system achieves high-precision and high-speed measurement for pellets’ geometrical scale and density. It can measure the pellets with diameter over 1 μm and height over 3 μm. Its measuring speed is 7 pellets/min and the function such as data displaying in real time，alarm，storage and inquiry，automatic report generation and user management are endowed.

13 Adaptive visual tracking based on DSPCA

XIANG Ruxi , LI Jianwei , FENG Hailiang

2014, 37(4):82-87. DOI: 10.11835/j.issn.1000-582X.2014.04.013

[Abstract](1525) [HTML](249) [PDF 6.41 M](1181)

Abstract:
In order to solve the problem resulted from tracking drift of single reference color histograms，a sort of particle filtering algorithm based on DSPCA(decomposition-sparse-principal component-analysis) is presented. The image set with complementary is accessed by DSPCA，which is fused by means of the new similarity as the new object model. Compared with the basic particle filtering，visual tracking decomposition and adaptive multiple cues fusion tracking algorithm in challenging scenarios，the presented method can robustly track the object in fast motion and the object which is mostly blocked.

14 Flow friction analysis of the water-cooled nozzle in the high-speed wire rod rolling process

LI Longjian , LIU Guichuan

2014, 37(4):88-92. DOI: 10.11835/j.issn.1000-582X.2014.04.014

[Abstract](1256) [HTML](294) [PDF 4.86 M](911)

Abstract:
Numerical simulation is performed to investigate the flow friction performance of the water-cooled nozzle used in the high speed rod rolling. A great deal of resistance characteristic data are obtained based on a series of numerical computations of flow process in the water-cool nozzle. The research results reveal the effects of the mass flow rate of the water，the diameter and the speed of the rod on the flow friction. The empirical formula is fitted with those computed resistance coefficients. Finally the formula is revised with the measured data from the actual product line，which will provide a theoretical basis for the design of the control cooling technology in the high-speed wire rod rolling process.

15 Finite element simulation of duct grouting to standard prestressed concrete beam

YAN Qiurong , XU Ying , KONG lingyun

2014, 37(4):93-99. DOI: 10.11835/j.issn.1000-582X.2014.04.015

[Abstract](1308) [HTML](298) [PDF 8.37 M](920)

Abstract:
For the duct grouting of prestressed beams，due to the narrow passageways grouting，the paste in the flow condition is very complex. In order to understand the grouting body in flow，the article establishes a three dimension finite element model of the grouting body，and uses the fluid mechanics software Fluent to analyze the grouting process of the standard prestressed beams through the finite element numerical method for the first time. The results show in the speed of cloud，the paste which is in a straight space and passes top space flows slow，may cause grouting defects. In the cloud of duct static pressure，the static pressure in the centre of the duct is greater than those on both ends. When paste is in hydration process，secrete water is forced to flow to the two ends，which causes grouting defects. The analysis results provide theoretical and actual testing data processing support for grouting nondestructive testing technology.

16 Conversion coefficient for backcalculated modulus of unbound aggregate base asphalt pavement

ZHUANG Chuanyi , YE Yali , WANG Lin

2014, 37(4):100-108. DOI: 10.11835/j.issn.1000-582X.2014.04.016

[Abstract](2285) [HTML](320) [PDF 7.75 M](1211)

Abstract:
In order to get pavement structure modulus which can real reflect pavement mechanical characteristics and the properties of pavement materials，four kinds of full-scale unbound aggregate base asphalt pavement test road are constructed，accelerated pavement testing is conducted and pavement deflection is tested. Based on FWD testing program，layered measure and analysis method are introduced to measure deflections，FWD deflection testing is conducted in different stages of pavement damage. The influence characteristics of loading level，position and pavement temperature on FWD backcalculated modulus are analyzed，the relationship between FWD backcalculated modulus and laboratory dynamic modulus is established，and the conversion coefficients of asphalt concrete，unbound aggregate and subgrade soil are put forward. The results show that the asphalt concrete modulus is greatly affected by temperature and wheel loads，asphalt layer backcalculated modulus conversion coefficients is of 0.5 to 1.0 if the pavement is in good condition，and it is of 1.3 to 1.5 if pavement top-down cracking is occurred. If the pavement is damaged at the bottom of the asphalt layer，the conversion coeefient is more than 1.5. The conversion coefficient of unbound aggregate is of 1.32 to 1.49；the subgrade soil backcalculated modulus conversion coefficient is related with stress level and soil types，the conversion coefficient of inverse modulus for soil base decreases with decreasing stress.

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