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| 1 | Powertrain parameter matching and optimal design of dual-motor driven electric tractor显示文摘The rationality of powertrain parameter design has a significant influence on the traction performance and economic performance of electric tractor.At present,researches on powertrain parameter design mainly focus on electric vehicles,and electric agricultural machinery draw much less attention.Therefore,a method of powertrain parameter matching and optimization design for electric tractor was proposed in this paper,which was based on dual-motor coupling drive mode.The particle swarm optimization(PSO)algorithm based on mixed penalty function was used for parameter optimization.Parameter optimization design was programmed using MATLAB.A simulation dynamic model with optimization design variables of electric tractor powertrain was established based on MATLAB/Simulink.Compared with the simulation results before optimization,the objective functions were optimized and the traction performance of electric tractor was improved,which indicated the effectiveness of the proposed method. | Yanni Chen Bin Xie Yuefeng Du Enrong Mao | 2019 | International Journal of Agricultural and Biological Engineering2019，12，1： | 4 |
| 2 | Height stability control of a large sprayer body based on air suspension using the sliding mode approach显示文摘When a high clearance self-propelled sprayer sprays,the sprung mass varies with the amount of liquid in the tank,which causes a change in the height of the sprayer body.This change not only is harmful to the sprayer ride comfort,but also has a greater impact on the sprayer application quality.In this paper,a large-scale high clearance self-propelled sprayer with air suspension was taken as the research object.Based on vehicle dynamics and air thermodynamics theory,a mathematical model of air spring inflation/deflation was established,then a 3 degree of freedom(3-dof)vertical dynamics model of sprayer air suspension was built.On this basis,the height control strategy of the sprayer body was formulated.Due to the nonlinear characteristics of air suspension,two control algorithms,namely sliding mode control and the on-off control,were used to design the suspension height stability controller,respectively.A simulation experiment was carried out by using the sprayer spraying crops as an example.The simulation experiment results showed that sliding mode control and on-off control could track and stabilize the height of the sprayer body when it changed under no excitation and D-grade road random excitation.However,due to strong nonlinearity and hysteresis of the pneumatic system,on-off control precision was poor.With the on-off control method,further reduction of the sprung mass would change the internal parameters of the pneumatic system,cause the air spring over deflation,even worse,the over deflation phenomenon presented a serious trend and cause system instability under random road excitation.Compared with on-off control method,sliding mode control approach had good control ability and precision due to its robustness to change in model parameters.The research will provide a reference for the height stability adjustment of large high clearance self-propelled sprayers during spraying and dosing operations. | Yu Chen Shuo Zhang Enrong Mao Yuefeng Du Jun Chen Shanju Yang | 2020 | Information Processing in Agriculture2020，7，1： | 4 |
| 3 | The inhibitory effects of siRNA expression vector on CXCR4 expression in prostate carcinoma cell lines显示文摘Objective: To investigate the inhibitory effects of RNAi (RNA interference, RNAi) expression vector on CXCR4 expression in prostate carcinoma cell lines. Methods: Small interference RNA(siRNA) expression vectors for CXCR4 gene were constructed and transfected into prostate carcinoma cell lines(PC-3m and LNCaP)with liposomes. The expression of CXCR4 was detected by RT-PCR and western blot. Results: The expression of CXCR4 mRNA and protein in the PC-3m and LNCaP cells was reduced by RNAi expression vectors. The inhibitory rate of CXCR4 mRNA expression in the PC-3m cells was 87.81%±10.20%,56.10%±9.32% at the 24th hour and the 48th hour, compared with 56.93%±8.78%,49.24%±11.23% in LNCaP cells. The inhibitory rate of the expression of CXCR4 protein was 64.71%±6.68%,58.66%±11.56% respectively. Conclusion: The expression of CXCR4 gene can effectively be inhibited by RNAi expression vectors. | Yuefeng Du Yifei Xing Fuqing Zeng Peng Lu Xianyin Liu | 2006 | Journal of Nanjing Medical University2006，20，2： | 3 |
| 4 | Enhanced tribological properties of aligned graphene-epoxy composites显示文摘The random distribution of graphene in epoxy matrix hinders the further applications of grapheneepoxy composites in the field of tribology.Hence,in order to fully utilize the anisotropic properties of graphene,highly aligned graphene-epoxy composites(AGEC)with horizontally oriented structure have been fabricated via an improved vacuum filtration freeze-drying method.The frictional tests results indicated that the wear rate of AGEC slowly increased from 5.19x10^(-6)mm^(3)/(N-m)to 2.87x10^(-5)mm^(3)/(N-m)with the increasing of the normal load from 2 to 10 N,whereas the friction coefficient(COF)remained a constant of 0.109.Compared to the neat epoxy and random graphene-epoxy composites(RGEC),the COF of AGEC was reduced by 87.5%and 71.2%,and the reduction of wear rate was 86.6%and 85.4%at most,respectively.Scanning electron microscope(SEM)observations illustrated that a compact graphene self-lubricant film was formed on the worn surface of AGEC,which enables AGEC to possess excellent tribological performance.Finally,in light of the excellent tribological properties of AGEC,this study highlights a pathway to expand the tribological applications of graphene-epoxy composites. | Yuefeng DU Zhenyu ZHANG Dong WANG Lezhen ZHANG Junfeng CUI Yapeng CHEN Mingliang WU Ruiyang KANG Yunxiang LU Jinhong YU Nan JIANG | 2022 | Friction2022，10，6： | 2 |
| 5 | Discovering context-aware conditional functional dependencies显示文摘有条件的功能的相关性(CFD ) 是为数据一致性的重要技术。然而, CFD 被限制到 1 ) 为一致性修理提供合理价值并且 2 ) 检测潜在的错误。这篇论文论述贡献的上下文知道的有条件的功能的相关性(CCFD ) 提供合理价值并且检测潜在的错误。特别,我们集中于自动地发现最小的 CCFD。在这篇论文,我们测量 CFD 的关系的现在的上下文相关性。相关 CFD 的重叠能提供导致修理的更多的精确性一致性的合理价值,并且一些相关 CFD 被合为 CCFDs.Moreover,我们证明发现最小的 CCFD 是 NP 完全的,我们设计精确方法和启发式的方法。我们也介绍统治价值在精确方法和启发式的方法便于这个过程。另外, CFD 的上下文相关性影响清洗结果。我们将为建议根据数据分发给上下文相关性的近似阀值。修理结果是 approvedmore 精确性,甚至由我们的实验评估证实了。 | Yuefeng DU Derong SHEN Tiezheng NIE Yue KOU Ge YU | 2017 | Frontiers of Computer Science2017，11，4： | 1 |
| 6 | Experiments and modeling of mechanism analysis of maize picking loss显示文摘Maize picking is the main form of maize harvest in China.Maize picking loss accounts for a large proportion of the current maize harvest loss.An experimental study and a theoretical analysis were conducted to explore the influencing factors and rules of maize picking loss.First,the boundary conditions,established by analyzing the mechanism of maize picking,determined the influences of maize picking loss.Then,single-factor experiments and a central composite design(CCD)method were used to determine the influence of various factors and their interactions on maize picking loss.Finally,the models of kernel loss and ear loss were set up to determine the optimal parameter combination of maize picking harvest.Field experiment verification was conducted.The results indicated that the optimal parameters of the maize picking harvest were the rotational speed of pulling rollers of 1120 r/min,operating speed of 1.94 m/s,the inclination of the header of 18°and clearance between the picking plates of 30 mm.By establishing these optimal parameters,the kernel loss rate was 0.065%,and the ear loss rate was 0%.The obtained experimental results and regression models could be used to predict the performance of the maize picking harvest,guide the adjustment of header working parameters,and provide a theoretical basis for reducing the mechanical loss of maize harvesting. | Zhen Zhang Ruijuan Chi Yuefeng Du Xiang Pan Naixi Dong Bin Xie | 2021 | International Journal of Agricultural and Biological Engineering2021，14，1： | 1 |
| 7 | Tractor path tracking control based on binocular vision显示文摘In the process of field operation management,determining how to accurately realize crop row identification and path tracking control is an essential part of tractor automatic navigation.According to the linear operation in the process of cotton field management,the tractor path tracking control system was designed based on binocular vision and the pure pursuit model.A new crop row detection method based on the Census transform and the PID control algorithm with dead zone were used.First,the upper computer software was developed by C++with the functions of parameter setting and image acquisition and processing.Second,an automatic steering controller was developed based on microprocessor MC9S12XS128 of Freescale.The control program was developed based on modular design using CodeWarrior during development of the PID-based automatic steering control strategy.Finally,a field experiment platform of tractor path tracking control was built,and field experiments under the actual cotton were conducted.The optimal visibility distance was determined by several previous experiments.When the tractor tracks the path with the optimal visibility distance in the growth environment of actual cotton crops,the mean absolute deviation of course angle was 0.95°,and the standard deviation was 1.26°;the mean absolute deviation of lateral position was 4.00 cm,and the standard deviation was 4.97 cm;the mean absolute deviation of front wheel angle was 2.99°,and the standard deviation was 3.67°.The experimental results show that(1)the crop row detection method based on Census transform can identify the crop line and plan the navigation path well,and(2)the tractor path tracking control system based on binocular vision has good stability and high control precision;thus,the control systemcan realize the automatic path tracking control of cotton line operation and meets the agricultural requirements of cotton field operation management. | Shuo Zhang Yunyi Wang Zhongxiang Zhu Zhen Li Yuefeng Du Enrong Mao | 2018 | Information Processing in Agriculture2018，5，4： | 1 |
| 8 | SSR Primer Screening for Marchantia convoluta by SAM Method显示文摘[Objectives] This study was conducted to study SSR primers in wild Marchantia convoluta by SAM method. [Methods] The M. convoluta genomic DNA was extracted by improved CTAB method,and the SSR primers for M. convoluta were selected through digestion,ligation,suppression PCR,pre-amplification,SAM method and PCR. [Results] The improved CTAB method extracted a high purity of DNA; the SAM PCR method gave clear bands; and 100 positive clones were sequenced,obtaining 86 sequences. [Conclusions] The SSR molecular markers could be used for analyzing the genetic diversity of M. convoluta. | Yuefeng WANG Fengfeng XIE Yuqing ZHOU Peilin DU Hua ZHU Jianbei TENG | 2017 | Agricultural Biotechnology2017，6，5： | 0 |
| 9 | Experimental study on the key factors of low-loss threshing of high-moisture maize显示文摘The rates of maize breakage and entrainment loss are high in the harvest of high-moisture maize,which remains an issue with the development of agricultural mechanization.In order to reduce the maize breakage and entrainment loss rates,the correlations among key factors,such as the threshing cylinder speed,concave clearance and feeding rate,and the rates of breakage and entrainment loss during high-moisture maize harvesting were studied in this paper.A single-factor experiment was carried out using a single-longitudinal-axial flow maize harvester,and an orthogonal experiment was carried out using single-and double-longitudinal-axial flow maize harvesters with the Taguchi experimental design method.The single-factor experiment revealed that when the cylinder speed increased,the breakage rate of maize decreased first and then increased,while the entrainment loss rate decreased.The breakage rate of maize decreased as the concave clearance increased,while the entrainment loss rate decreased first and then increased.The optimum value of the concave clearance was positively correlated with the ear diameter of maize;Additionally,the minimum breakage rate of maize occurred when the feeding rate was at the rated value,and the entrainment loss rate increased as the feeding rate increased.The orthogonal experiments revealed that the importance of cylinder speed,feeding rate,concave clearance on the maize breakage and entrainment loss rates were in descending order.The optimum values of parameters for the single-longitudinal-axial flow maize harvester were 370 r/min cylinder speed,40 mm concave clearance and 10 kg/s feeding rate.The optimum values of parameters the double-longitudinal-axial flow maize harvester were 550 r/min cylinder speed,35 mm concave clearance and 10 kg/s feeding rate.The research can provide a reference for parameter configuration and control strategy for the longitudinal-axial flow maize harvester with high-moisture maize. | Xiaolong Zhu Ruijuan Chi Yuefeng Du Jiahao Qin Zexin Xiong Weitong Zhang Xiaoyu Li | 2020 | International Journal of Agricultural and Biological Engineering2020，13，5： | 0 |
| 10 | Image moments-based visual servoing control of bagged agricultural materials handling robot显示文摘Manual handling is less efficient and sometimes even hazardous to humans in many areas,for example,agriculture.Using robots in those areas not only avoids human contact with such dangerous agricultural materials but also improves working efficiency.The motion of a robot is controlled using a technique called visual servoing that uses feedback information extracted from a vision sensor.In this study,a visual servoing method was proposed based on learning features and image moments for 3D targets to solve the problem of image moment-based visual servoing.A Gaussian process regression model was used to map the relationship between the image moment invariants and the rotational angles around the X-and Y-axes of the camera frame(denoted asγandβ).To obtain maximal decoupled structure and minimal nonlinearities of the image Jacobian matrix,it was assumed two image moment features,which are linearly proportional toγandβ.In addition to the other four standardized image moment features,a 6-DOF image moment-based visual servoing controller for the agricultural material handling robot was designed.Using this method,the problem of visual servoing task failure due to the singularity of the Jacobian matrix was solved,and it also had a better convergence effect for the part of the target image beyond the field of view and large displacement visual servoing system.The proposed algorithm was validated by carrying out experiments tracking bagged flour in a six-degree-of-freedom robotic system.The final displacement positioning accuracy reached the millimeter level and the direction angle positioning accuracy reached the level of 0.1°.The method still has a certain convergence effect when the target image is beyond the field of view.The experimental results have been presented to show the adequate behavior of the presented approach in robot handling operations.It provides reference for the application of visual servoing technology in the field of agricultural robots and has important theoretical significance and practical value. | Han Li Zhijiang Zuo Ruijuan Chi Yuefeng Du Enrong Mao | 2023 | International Journal of Agricultural and Biological Engineering2023，16，1： | 0 |
| 11 | Design and experiment of corn low damage threshing device based on DEM显示文摘Kernel broken rate is an important index to evaluate the maize kernel direct harvesting quality.In view of the problem of the high kernel broken rate in the present maize harvester,a new threshing cylinder was designed in this study.This device utilized rasp bar to achieve low damaged maize ears threshing.In order to determine the structure and working parameters of threshing device,the“crop-crop”contact model and the“crop-mechanical”interaction system were established and analyzed based on the discrete element method first,and the mathematical expressions of the related kinematic response of maize kernel under the external force were obtained.Then,the structure parameters of rasp bar were studied through EDEM simulation experiment,and the working parameters were determined through test-bed experiment.Finally,the simulation experiment results and test-bed experiment results were verified through field experiment.The results showed that when the threshing cylinder speed was 356 r/min,the concave clearance was 40 mm,the installation distance of rasp bar was 250 mm with 50Mn steel,and the feeding amount was 8 kg/s,the kernel broken rate was 1.93%,which satisfied the requirements of maize harvest standard.This study proved that the DEM(Discrete Element Method)can be adopted to guide the optimization design of mechanical structure,and it has certain value for the research and development of operation equipment of other agricultural crops. | Xiaoyu Li Yuefeng Du Enrong Mao Yan’an Zhang Lei Liu Dafang Guo | 2023 | International Journal of Agricultural and Biological Engineering2023，16，3： | 0 |
| 12 | Path-tracking control based on a dynamic trigonometric function显示文摘With the rapid development of the modern vehicle industry,the automated control of new vehicles is in increasing demand.However,traditional course control has been unable to meet the actual needs of such demand.To solve this problem,more precise pathtracking control technologies have attracted increased attention.This paper presents a new algorithm based on the latitude and longitude information,as well as a dynamic trigonometric function,to improve the accuracy of position deviation.First,the algorithm takes the course deviation and adjustment time as the optimization objectives and the given path and speed as the constraints.The controller continuously adjusts the output through a cyclic“adjustment and detection”process.Second,through an integration of the steering,positioning,and speed control systems,an experimental platform of a path-tracking control system based on the National Instruments(NI)myRIO controller and LabVIEW was developed.In addition,path-tracking experiments were carried out along a linear path,while changing lanes,and on a curved path.When comparing and analyzing the experimental results,it can be seen that the average deviation in lateral displacement along the linear and curved paths was 0.32 and0.8 cm,and the standard deviation of the lateral displacement was 2.65 and 2.39 cm,respectively.When changing lanes,the total adjustment time for the vehicle close to the target line to reach stability was about 1.5 s.Finally,the experimental results indicate that the new algorithm achieves good stability and high control accuracy,and can overcome directional and positional errors caused by road interference while driving,meeting the precision requirements of automated vehicle control. | Yunyi Wang Shuo Zhang Zhongxiang Zhu Zhen Li Yuefeng Du Lizhi Fang | 2019 | Information Processing in Agriculture2019，6，1： | 0 |
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