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April 30,2016
Volume 9,Issue 8
Pages -
Subject Area:Electrical Engineering,Engineering Thermophysics,Basic Subject of Hydraulic Engineering,Air Transport

Title: Hazard perception test and analysis on its reliability and validity of driver

Authors: SUN Long, CHANG Ruosong, LI Shuang
PP: 863-867
Abstract: In order to develop a hazard perception test (HPT) for Chinese driver by using dynamic traffic video, we tested 152 drivers by combining reaction time method and eye movement method. 75 dynamic traffic videos shooting from the drivers’ view, among which 50 videos contained a latent hazard, were showed by Tobbi T120 eye tracker. The final test contained 26 video clips. Results showed that the reliability of the test (Cronbach’s α) was 0.903. The overall classification accuracy of the test was 82.7%. Further analysis of eye movement data verified the validity of the test. If drivers took less time to first fixate hazards and dwelled more time on them, they could response to hazards quicker. Therefore, the reliability and validity of HPT was well and it suited for assessing Chinese drivers’ hazard perception ability.
Keywords: safety psychology; hazard perception; eye movements; hazard perception test; dynamic traffic video

Title: Burned area prediction of urban district fire based on BP artificial neural network

Authors: ZHOU Dechuang, DING Chao, CHEN Mingyi
PP: 856-862
Abstract: The fire spreading processes under different parameters in a urban district are computed by fire spreading probability model of cellular automata. The investigated parameters include the location of ire source and environmental wind. The BP artificial neural network (ANN) model of burned area is built by Matlab neural network tool on the basis of cellular automata simulation results. The model can simulate the changing process of burned area under different environmental winds, providing the certain reference for city planning and fire control.
Keywords: safety engineering; burned area; neural network; urban district; fire spread

Title: Research on SVM-DTC AC variable frequency speed regulation experimental platform with dead-time compensation

Authors: SUN Tiecheng, Narentuya, LIU Lu
PP: 846-855
Abstract: The AC speed regulation experimental platform based on SVM-DTC control algorithm has overcome the shortcomings of traditional control algorithm, and the good operating performance has been verified in experiments. But the presence of dead-time in the AC speed control algorithm can cause the problem of dead-time effect. To solve the problems above, we proposed the dead-time compensation based on current vector, analyzed the dead-time compensation strategy, and designed AC variable frequency speed regulation experimental platform based on SVM-DTC algorithm with dead-time compensation. Experimental results show that the problem of dead-time effect caused by dead-time has been eliminated, and the operating performance of the system has been improved effectively.
Keywords: electrical engineering; variable frequency speed regulation; SVM-DTC algorithm; zero current clamp; dead-time compensation

Title: Analysis on failure of steam-side oxide scale on high-temperature boiler tubes using acoustic emission monitoring technique

Authors: HUANG Junlin, QI Jing, XIE Jianwen, ZHOU Keyi
PP: 838-845
Abstract: Cracking and exfoliation of steam-side oxide scale on high-temperature boiler tubes can affect the safety and economy of thermal power units. In this work, uniaxial tensile tests using acoustic emission (AE) monitoring technique were implemented to study the failure process of steam-side oxide scale on boiler tubes. Four different stages including oxide cracking, fast multiplication, cracking saturation and oxide exfoliation are encountered successively. Frequency spectra of AE signals captured from pure substrate and specimen experiencing different loading stages were obtained by performing fast Fourier transform. In the frequency spectra, three different peak frequency bands, 100-170, 175-250 and 280-390 kHz were identified, which were inferred to respectively corresponding to plastic deformation of substrate, oxide cracking, and oxide exfoliation with the aid of SEM observations, and can thus be used for determining various oxide scale failure modes.
Keywords: engineering thermophysics; steam-side oxide scale; failure; boiler; superheater; acoustic emission

Title: Strip profile control of the roughing mill for non-oriented electrical steel

Authors: DONG Qiang1, CAO Jianguo1, LI Yanlin, KONG Ning, ZHOU Yunsong, YAN Tanli
PP: 829-837
Abstract: Profile and flatness control is the bottleneck constraints in rolling field for schedule-free rolling of wide electrical steel. Taking a large hot tandem mill as the research object, the wear behaviors and service conditions of hi-Cr iron work roll, HSS work roll and backup roll in the roughing mill were investigated by industry experiments and tracking measurements. A constitutive relation model for electrical steel in austenite zone was built and a 3D roll-strip FE model was established. The varying contact backup roll was developed to meet a large number of the same wide rolling strategy. The merging effects of HSS work roll and VCR backup roll were analyzed. Industry application showed that roll contour self-maintainance and severe roll wear were improved, roll spallings were eliminated and the shape quality of the supplied strips for the finishing mill was increased.
Keywords: plastic forming technology and equipment; electrical steel; hot rolling; schedule-free rolling; FE modeling; strip profile control

Title: Simulation research on joint motion analysis and control strategy for rehabilitation manipulator

Authors: WEN Weisong, GAO Hong
PP: 822-828
Abstract: We studied an upper limb rehabilitation manipulator and its control approach, applying for patients’ training. Virtual simulation of the upper limb rehabilitation manipulator was made in virtual environments to simulate the motion parameters variation of wrist of patients when training. In this article, a velocity function of joint based on cubic fitting was proposed, and an approach of gravity compensation was presented theoretically. Synthesizing velocity variation and gravity compensation factors, the driving torque function of elbow joint was solved. This control strategy can control each motor of joints steadily.
Keywords: mechanical manufacturing and automation; rehabilitation manipulator; virtual simulation; gravity compensation

Title: Bionic optimization method based on BioTRIZ-Isight

Authors: WANG Wenlong, XU He, HU Mingyu
PP: 813-821
Abstract: In this paper, the implementation of bionic design as the research object and from the aspect of improving the efficiency of research and development, an bionic optimization method based on BioTRIZ-Isight has been proposed. The biological analogies can be found through the joint application BioTRIZ conflict matrix and biological case library, and the bionic design can be obtained by the method of geometric characteristics extracted and reconstructed. Isight parameter optimization platform is also introduced to improve the efficiency of product development. At last, based on the BioTRIZ-Isight bionic design method, the bluff body of the electromagnetic vortex flowmeter has been optimized and the effectiveness of the proposed method is verified.
Keywords: mechanical design; BioTRIZ; Isight; bluff body

Title: Study on load spectrum compiling method and load measurement of harvester frame

Authors: LANG Jian, LIU Shourong, ZHAI Zhiqiang, LI Fuqiang
PP: 804-812
Abstract: We get the strain change data of the maize harvest machine frame weak point in different working conditions by building a strain test system. We analyze the data in Matlab and get the load spectrum by using the statistics notation measurement. The harvest machine has a complex working environment, while the test system is designed to be modified and easily changing the strain test patch. Statistics notation measurement is simplified by data analysis program. Computing speed and accuracy is improved and the program is convenient for statistic analyzing the random load. This study provides a good reference for testing the agricultural machine parts load and compiling load spectrum chart.
Keywords: mechanical strength; maize harvest machine; frame; load spectrum; rain-flow notation

Title: Research on pressure and flow characteristics of gas film field of radial aerostatic bearing based on Workbench

Authors: LI Shusen, YUAN Yue
PP: 799-803
Abstract: Taking orifice hydrostatic gas bearing as the research object, we study gas film flow field pressure and flow characteristics for hydrostatic gas bearing using Workbench software. Three-dimensional modeling of the bearing is structured, and the model is given structured and non-structured mesh. Based on the model ANSYS Workbench software analysis, high-speed distribution of the bearing pressure, pressure contours, the impact of the flow field inside the bearing pressure contours and orifice diameter on the mass flow are obtained.
Keywords: mechanics; aerostatic bearing; pressure of gas film flow field; flow characteristics; Workbench

Title: Study on implement of virtual water strategy in Ordos city

Authors: GUO Shaofeng, JIA Debin
PP: 792-798
Abstract: Virtual water theory is a new field of water management. Water By introducing the basic theory and calculation method of virtual water and combining with the actual situation and related information of Ordos, one of the most water shortage cities in the north of China, this paper calculated the virtual water in agriculture, industry, ecology and resident consumption during 1998-2011, and proposed the strategy for adjusting planting structure and industrial layout, promoting the rational allocation of water resources and easing the local water shortage.
Keywords: water economics; virtual water; virtual water strategy; Ordos city

Title: A review of flow simulation in tidal rivers

Authors: ZHANG Xiaoqin
PP: 785-791
Abstract: Flow movement in tidal rivers is complicated under the interaction of upstream flood and downstream tide. We summarized the flow movement characteristics, flow simulation methods and error correction methods in tidal rivers. More works are needed to study the mechanism of combined effects of river flow and tide, and develop technologies with simple structure and high accuracy for flow simulation and error correction in tidal rivers in application.
Keywords: basic subject of hydraulic engineering; flow simulation; review; interaction of river flow and tide; error correction; tidal river

Title: Development needs prediction of China\'s general aviation using improved gray model

Authors: SONG Weiwei, ZHANG Liguo, LI Jingkui
PP: 778-784
Abstract: Using the improved gray system theory, we predict general aviation industry development indicators that is the number of flight hours and the number of general aviation enterprises of China. Through the establishment of gray prediction model, and at the meantime, gray prediction model is improved by using Markov chain theory, and both models are applied to predict. The results show that using the prediction model by Markov chain theory correction, the prediction accuracy has been greatly improved with more accurate results. Forecast results indicate that the rapid development of China’s general aviation and the growth potential is obvious.
Keywords: air transportation; general aviation development needs; gray prediction; improved gray prediction; Markov chain; model

Title: Study on the optimum design scheme of child restraint system’s dynamic test-oriented deceleration-type trolley

Authors: WEI Zhe，QIANG Yi
PP: 770-777
Abstract: The purpose of the study was, by simple and effective means, to ascertain the influencing factors for the deceleration curves of child restraint system’s dynamic test, and find a solution to generate the required deceleration curves conveniently, thus optimizing test impulses by adjusting part or all of the according factors, with the fewest tests and the lowest cost. The study was based upon Proe-Ansys-Lsdyna modelling and solving technique, and tests were carried out to verify the reliability of the simulation scheme. After the verification, part or all of the factors affecting the deceleration curves in dynamic tests underwent proper adjustments, and they could include the steel pipes’ thickness, slope, heat treatment process, the trolley’s weight, velocity, and the size of sliding block’s hole, etc. When all the factors influencing deceleration curves in tests were ascertained, a method which could conveniently and effectively produce deceleration curves for the deceleration-type trolley which is generally cheaper and therefore more popular with laboratories and factories of small scale, was then recommended to optimize the required curves in child restraint system’s dynamic test by comparison between influences of the factors upon the curves in simulation. Furthermore, the feasibility of other similar energy-absorbing methods was explored. However, the study depended to some extent upon simulations which were adopted to minimize the number of dynamic tests and to reduce the test cost, with tests of limited number for verification. Although the tendencies of curves in simulations and tests resemble each other, the ideal type of simulations would unavoidably be affected by the complexity of test conditions, i.e., simulation results could not be identical to test ones because of even tiny changes in test conditions. Meanwhile, the method to generate deceleration curves was limited to deceleration-type trolley only. Nevertheless, steel pipes with different slopes, thicknesses and yield stresses, together with other parameters concerned such as trolley’s velocity, weight and the size of sliding block’s rectangular hole could be combined to control the shape of deceleration curves easily, thus fulfilling the according requirements of deceleration-type trolley. Finally, deceleration curves required by child restraint system’s dynamic test can be generated successfully by means of changing the parameters of pipes and trolley, and the adjustment is simple and effective, which is suitable for small and middle sized enterprises and laboratories.
Keywords: transportation safety engineering; child restraint system; dynamic test; deceleration; trolley; steel pipe

Title: Application of negative compensation amount in ship precision control

Authors: MEI Zhi, FAN Huaqing
PP: 765-769
Abstract: The core content of this paper is to put the correct negative compensation in precision control. Combined with the corporate practice, we proposed a reasonable dimension compensation to resolve the actual ship construction problem of machining tolerances and welding heat distortion due to cutting, assembly, welding, etc. The application of negative compensation has great significance to improve shipbuilding quality, minimize on-site correction of the assembly operations, shorten the shipbuilding period, and lower the production costs.
Keywords: ship engineering; precision control; negative compensation; ship building

Title: Review on interaction between sea ice and wave/current/wind

Authors: NI Baoyu, XUE Yanzhuo, SUN Shili
PP: 759-764
Abstract: With the increasing possibility for arctic shipping and polar resources exploration, more attentions are being paid to polar environmental loads, especially for the ice loads. Under the forces of wave, current and wind, the ice motion including drifting, rafting, collision and fracture will happen. On the other hand, the propagations and evolutions of wave, current and wind will be changed with the effects of sea ice. From the two views of sea ice and wave/current/wind, the research progress and technical challenges of the interaction between sea ice and wave/current/wind have been reviewed and discussed, as well as the corresponding theoretical models, numerical methods and experimental techniques. This paper aims at providing some references for naval architecture of polar shipping and resources.
Keywords: ship engineering; sea ice; review; wave; current; wind

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