Volume 42,Issue 7,2019 Table of Contents

1 A neural network fuel consumption model hybrid of EVT system

YANG Yalian , DENG Qiyuan , LIU Qiangshou , PEI Huanxin

2019, 42(7):1-9. DOI: 10.11835/j.issn.1000-582X.2019.07.001

[Abstract](929) [HTML](523) [PDF 1.31 M](1166)

Abstract:
In order to quickly screen the hybrid electric vehicle powertrain (EVT, electric variable transmission) configurations based on their fuel economy, a configuration matrix of hybrid EVT system is proposed and the dynamic model of hybrid EVT system is established on the basis of graph theory hierarchical drawing model of hybrid EVT system. A fuel consumption model of hybrid EVT system that combines general regression neural network and dynamic programming algorithm is established and its effectiveness is verified by comparing the calculation results of GRNN fuel consumption model and that of the DP simulation of the test configurations.

2 Multi-objective optimization method for FJSP under mixed work calendars

ZENG Qiang , CHANG Menghui , WANG Menghua , ZHANG Jinchun

2019, 42(7):10-26. DOI: 10.11835/j.issn.1000-582X.2019.07.002

[Abstract](739) [HTML](402) [PDF 1.98 M](931)

Abstract:
This paper presents a multi-objective optimization method based on NSGA Ⅱ to solve a kind of flexible job-shop scheduling problem(FJSP) under mixed work calendars. A time reckoning mechanism based on the machine's work calendar is proposed and related time reckoning functions are designed. A two-segment encoding method is used to encode the processes and equipments. A two-segment crossover and mutation operator is respectively used to implement crossover operation and mutation operation, in which an improved strategy of genetic operators is applied to ensure feasibility of the progeny individuals and reduce amout of calculation. The time reckoning functions proposed above are used to calculate start time and end time of each operation accurately so as to ensure feasibility of each scheduling scheme in the decoding operation. The following two techniques are employed to shorten production cycle so as to improve quality of each scheduling scheme in the decoding operation:1)Operation time is subdivided into adjusting time and processing time so that the machine of the next operation can be adjusted in advance. 2)A forward extrusion scheduling method is used to arrange each operation so as to reduce idle time of the machines. The research result shows that the proposed method can provide an effective Pareto set of the flexible job-shop scheduling problem under mixed work calendars for the dispatcher.

3 Human pulse wave simulation analysis based on transmission line model

CAI Xiao , ZHAO Liangju , ZHOU Zhenggang , JIANG Yuhuan

2019, 42(7):27-35. DOI: 10.11835/j.issn.1000-582X.2019.07.003

[Abstract](893) [HTML](679) [PDF 1.18 M](1144)

Abstract:
A transmission line model was established by using 55 human arterial trees to simulate the propagation of pulse wave in human arterial tree, and the effect of resistance change was investigated by changing the peripheral resistance of the model branch under the condition of the settled volume flow rate wave of cardiac output. The results show that with the increase of the peripheral resistance of a branch, its blood flow rate drops rapidly, the rise of the average blood pressure of the aorta and radial artery can be caused by the increase of the resistance ratio of different organs, and the trend of the elevation decreases gradually. When η is set as 4, the radial artery mean pressure is 2.86%,4.55%,1.90%,12.15%,9.81% and 1.49% higher than normal respectively with the flow resistance increase of liver, spleen, stomach, superior mesenteric, right kidney and inferior mesenteric branch. The objective relationship between pulse wave harmonics and the pathological changes of the organs is the basis of pulse diagnosis in traditional Chinese medicine. By analyzing the pulse wave frequency domain of radial artery, it is found that the connection between the amplitude of pulse wave and the change of peripheral resistance of each organ is not obvious. And the effect of cardiac self-regulation with different organ lesions should be considered in the simulation.

4 Building grid generation method for complex surfaces by slicing and reconstruction

LI Tierui , WU Hui , GAO Boqing , SHAN Yanling

2019, 42(7):36-41. DOI: 10.11835/j.issn.1000-582X.2019.07.004

[Abstract](721) [HTML](923) [PDF 1.43 M](924)

Abstract:
A surface slicing and reconstruction method for complex surfaces with trimmed boundaries and holes is presented in this paper, by which the negative effects of trimmed boundaries and holes can be removed and the quality of building grid generation can be improved. Firstly, the boundaries of slices are drawn on the surface. Secondly, the adapted polygon construction method is applied to obtain the topological relationships to recognize the slices. Thirdly, the interpolation and relaxation method is used to achieve uniform n×m regular samplings. Then the slices are reconstructed to get sub-surfaces independent of the original surface, on which the grids are generated to obtain sub-grids. At last, the sub-girds are combined and relaxed on the original surface. Several cases are delivered, showing that the grids are uniform, smooth and harmonious near the boundaries.

5 Study of calculation of negative skin friction on piles in high filled embankment after dynamic compaction considering consolidation effect

YAN Xiaoqi , HU Ruigeng , SHI Wei , SHUI Weihou , ZHANG Wenlong

2019, 42(7):42-53. DOI: 10.11835/j.issn.1000-582X.2019.07.005

[Abstract](739) [HTML](855) [PDF 2.42 M](1156)

Abstract:
The paper put forward the method of calculating the values of negative skin friction with the consolidation time on piles based on the field tests on high filled embankment after dynamic compaction. The proposed method calculate the values of skin friction respectively according to the improvement depths by dynamic compaction and non-improvement depths, using Terzaghi consolidation theory to calculate soil settlements to reflect the influence of consolidation effects on skin friction, using interference shear tests with soil and concret to get load transfer function between soil and piles to reflect the influence of relative deformation, and calculating the values of negative skin friction by finite difference method. Based on the comparative analyses of the results of the calculation and field testing, it is proved that the changing tendency of negative skin friction with depth by the calculation corresponds with that by field testing. The values of negative skin frication by field testing are about 0.5 of theoretical values by the calculation, and it is advisable to multiply the latter by a reduction coefficient of 0.5 when using them in projects.

6 Effect of interactive aging considering ultraviolet on rheological properties of SBR modified asphalt and analysis of the aging mechanism

CHEN Huiqiang , LI Chenglin , SUN Jianbang , HE Qiang

2019, 42(7):54-62. DOI: 10.11835/j.issn.1000-582X.2019.07.006

[Abstract](651) [HTML](505) [PDF 1.12 M](1179)

Abstract:
Considering the influence of ultraviolet aging on the properties of SBR modified asphalt, two interactive aging methods (1. SBR modified asphalt +RTFOT+PAV+UV; 2. SBR modified asphalt +RTFOT+ UV+PAV) were used to prepare aged asphalt, and the five kinds of aged asphalt were tested by DSR, BBR, DSC differential heat test and IR spectroscopy. The results showed that the rheological properties of SBR modified asphalt after short-term aging were similar to that after UV aging and PAV aging respectively. However, the rheological properties and aging degree of SBR modified asphalt after further aging were significantly changed after PAV aging and UV aging respectively, and UV aging effect on asphalt was very obvious. The interactive aging results of different aging sequences were also quite different. Compared with the first aging mode, the second one had a more significant effect on the rheological properties of SBR modified asphalt. PAV and UV aging have different aging mechanisms respectively, and the experimental results of SBR modified asphalt undergoing interactive aging were the concrete embodiment of the superposition of these two different aging mechanisms.

7 Influence of composite foundation embedded depth on the failure modes of stone columns

XIAO Chengzhi , XIA Boyang , ZHENG Gang , LIU Zhi , ZHOU Haizuo

2019, 42(7):63-69. DOI: 10.11835/j.issn.1000-582X.2019.07.007

[Abstract](728) [HTML](414) [PDF 1.23 M](967)

Abstract:
Performance of stone columns in composite foundation was investigated through finite difference method(FDM) that was verified by published experimental results of model tests, and then the effect of embedded depth of composite foundation on failure mode of single column and group columns in saturated clay soil was analyzed. The research results show that with the increase of the embedded depth of composite foundation, the surrounding pressure of the single column increases, the lateral constrains function is enhanced, the horizontal maximum deformation along stone columns reduces, and the failure location move down gradually along stone column. In the cases of a group of stone columns, the failure mode of columns is determined by the location of columns under composite foundation. Compared with side stone columns whose failure location is near to the top of the columns, the failure of the central column is located in the deeper parts of the columns. The lateral restraint effect of the foundation embedded depth on the side column is obvious. The failure mechanism of the friction columns transforms from the initial bulging(shearing)along the horizonal direction to downward penetration when the embedment depth becomes large.

8 Plastic deformation analysis of double-layer continuous paving for large thickness water stabilized base course

FANG Naren , WANG Xuancang , YE Hongyu , ZHANG Chunan

2019, 42(7):70-78. DOI: 10.11835/j.issn.1000-582X.2019.07.008

[Abstract](755) [HTML](798) [PDF 1023.77 K](916)

Abstract:
In order to obtain the plastic deformation law of the base under large thickness continuous paving, and find solution to the problem of lack of relevant control standards for the construction smoothness of large thickness continuous paving technology, the incremental elastic Duncan-Chang model is studied and improved by using D-P yield criterion. The yield limit of uncured water-stable mixture is 220 kPa by triaxial shear test and field test, and the initial tangent modulus is determined to be 500 kPa, from which a prediction formula for deformation value of uncured cement stabilized macadam base during construction period is obtained. Then the number of repeated loads in the most unfavorable position of the pavement is calculated, and the Wolff and Visser permanent deformation prediction model is introduced to establish the construction displacement prediction model of the lower bearing stratum. Finally, by studying the smoothness transfer law and the disturbance effect of the construction vehicles on the base stratum under the double-layer continuous paving, the smoothness control principle of the continuous paving is proposed. The smoothness of middle and lower layers of continuous paving layer should be controlled according to the construction standard of the lower layer, and that of the other layers should be controlled according to the traditional paving construction standard.

9 Preparation of porous montmorillonite and adsorptionproperties study of Pb(II) on It

ZHOU Zhifang , ZHANG Youxian , ZHAO Baiping , HUANG Tao , SUN Hanxue , JING Lingyun

2019, 42(7):79-87. DOI: 10.11835/j.issn.1000-582X.2019.07.009

[Abstract](677) [HTML](759) [PDF 1.40 M](948)

Abstract:
To improve adsorption propertiesof Pb(Ⅱ) onmontmorillonite,porous montmorillonite(PM) is prepared using CaCO₃ porogen and Na-montmorillonite material. The properties of PM are characterized by scanning electron microscopy(SEM),Fourier transform infrared spectrum (FTIR) and X-ray diffraction(XRD), and the adsorption properties of Pb(Ⅱ) on PM are discussed.The experimental results show that PM has abundant pores.With the increase of PH value,adsorption capacity by PM of Pb(Ⅱ) increases first and then decreases at 25℃,and the adsorption capacity is the highest when initial pH is 5.5.The adsorption process accords with the pseudo-second order kinetics model and the adsorption isotherm accords with Langmuir equation. The saturated adsorption capacity is 143.5 mg/g at 25℃,when pH is 5.5.

10 OMP-DAMAS beamforming acoustic source identification

WU Guijiao , LI Wenba , HE Liuhai

2019, 42(7):88-94. DOI: 10.11835/j.issn.1000-582X.2019.07.010

[Abstract](1005) [HTML](805) [PDF 2.95 M](1137)

Abstract:
Orthogonal matching pursuit applied to the deconvolution approach for the mapping of acoustic sources inverse problem (OMP-DAMAS) is characterized with high resolution and high location accuracy by reducing mainlobe and eliminating sidelobes.The change rules of the acoustic source identification results with signal frequency, iteration number and signal to noiseratio (SNR) were explored based on numerical simulated incoherent sources identification imaging maps and deviation value. The results are listed as following. OMP-DAMAS can improve resolution and location accuracy effectively. Excellent performance and robustness are guaranteed for medium and high frequency source. Acoustic sources can be identified with clear map when the algorithm is applied to sources with frequency higher than 2 300 Hz and SNR higher than 0 dB. The number of reconstructed sources depends on iteration number, while sidelobes can be eliminated by setting dynamic range properly. These conclusions have guiding significance for the application of the OMP-DAMAS. Furthermore, the feasibility of the method has been validated through a physical experiment on acoustic source identification of several loudspeakers.

11 CEEMDAN adaptive threshold denoising algorithm in application to seismic direction

LIU Xia , SONG Qihang

2019, 42(7):95-104. DOI: 10.11835/j.issn.1000-582X.2019.07.011

[Abstract](868) [HTML](874) [PDF 1.36 M](1329)

Abstract:
An adaptive threshold denoising algorithm based on complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN) is proposed in this paper. The noisy signal is decomposed into several modal components(IMF) by CEEMDAN algorithm. Based on the sample entropy theory, the adaptive selection of high frequency components in IMF components is realized, and the noise figure in high frequency components is located according to the different correlation between noise and useful information or the original signal. The main noise interval is selected by energy entropy, and the noise coefficient variance of the main noise interval in high frequency components is used as the threshold. Threshold denoising of high-frequency components is carried out to further remove noise and retain useful information in high-frequency. Finally, high-frequency components and low-frequency components separated from signal-noise are reconstructed. The denoising of synthetic and actual seismic signals is processed separately and compared with conventional denoising algorithms. Data simulation and experimental results show that when the signal-to-noise ratio of the original signal is 0.5 dB, the signal-to-noise ratio obtained by the conventional and improved algorithms is 4.55 dB and 9.97 dB respectively, which indicates significant improvement in the signal-to-noise ratio, achieving the purpose of random noise suppression and realizing the self-adaptive selection of high-frequency components and the re-extraction of useful information from high-frequency components.

12 Main steam pressure control technique based on mismatch compensation Smith predictor and RBF neural network

GAO Jin , ZHANG Jiayan , FENG Xugang , YAO Fengqi

2019, 42(7):105-113. DOI: 10.11835/j.issn.1000-582X.2019.07.012

[Abstract](554) [HTML](529) [PDF 1.78 M](808)

Abstract:
To solve the problems of large lag, uncertainty and gas disturbance of main steam pressure control system object of gas-fired power boiler,a control scheme based on mismatch compensation Smith prediction and RBF neural network is designed. The RBF neural network's online learning ability is used to adjust the parameters of the conventional PID, and the mismatch compensation Smith prediction controller to compensate the pure hysteresis in the system.The improved algorithm effectively solves the problem of mismatch of dynamic characteristic model and pure lag of main steam pressure object in thermal power boiler. The simulation research and practical application show that the control method has good stability and anti-interference ability for the main steam pressure control of thermal power boilers.

13 Backstepping finite time sliding mode control for multi-joint manipulator with total disturbance

GUO Yijun , XU Jianming

2019, 42(7):114-122. DOI: 10.11835/j.issn.1000-582X.2019.07.013

[Abstract](840) [HTML](863) [PDF 1.50 M](1216)

Abstract:
In this paper, a backstepping finite time sliding mode control algorithm considering the system total disturbance is designed for the trajectory tracking control of multi-joint manipulator with model parametric perturbation and external bounded disturbances. Firstly, the system dynamics model is formulated as a strict feedback form, and the uncertainty factors such as model parameter perturbation and external bounded disturbances are considered as the total disturbance of the system which is then estimated by a nonlinear extended state observer developed for improving the robust performance of the system. Secondly, the backstepping finite time sliding mode controller is designed based on the traditional backstepping method and the finite time sliding mode control technique. Finally, the Lyapunov stability theory is employed to prove that the position vector of the multi-joint manipulator can stably track the desired position vector within finite time. The comparison of simulation results is presented to verify the effectiveness of the proposed method.

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