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Design and parameter optimization of air-suction wheel type of seedmetering device with elastic pad for maize

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International Journal of agricultural and Biological engineering 2024年第4期17卷 116-127页

作者： Yuhuan Sun Junhai Guo Linrong Shi college of mechanical and electrical engineering Gansu Agricultural UniversityLanzhou 730070China college of mechanical and electrical engineering Lanzhou University of TechnologyLanzhou 730070China

Due to the maize growing agronomy requires ground covered by mulch film in the arid zones of the China Northwest region,the seed-metering device must roll over,break the film,and then throw seeds into ***,the uneven ground can cause the seed-metering device to shake,reducing seed-metering *** improve the adaptability for different shapes of maize seeds,a air suction wheel type seed-metering device with elastic pad was developed for better seed extraction and bump ***,the advantages and influencing factors of the elastic pad were analyzed through four processes of metering ***,the velocity distributions of six diameters of the suction hole are compared to determine the range with ***,a one-factor experiment was conducted to analyze the pattern of the factors(the seed layer height,the critical vacuum,the rotational speed of the seed disk,and the suction hole diameter)influencing the metering seed ***,a five-level quadratic rotation orthogonal design was used to optimize the *** show that the optimal values are that the seed layer height is 40 mm,and the critical vacuum is 2.85 kPa,and the rotational speed of the seed disk is 20.1 r/*** validation experiment resulted in a 93.79%qualified index,with a 4.02%missing index and a 2.19%multiple index.

关键词： maize seeds seed-metering device with air suction elastic suction parameter optimization

Cotton leaf disease detection method based on improved SSD

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International Journal of agricultural and Biological engineering 2024年第2期17卷 211-220页

作者： Wenjuan Guo Shuo Feng Quan Feng Xiangzhou Li Xueze Gao college of mechanical and electrical engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China college of mechanical and electrical engineering Sichuan Agricultural UniversityYa’an 625014China

In response to the problems of numerous model parameters and low detection accuracy in SSD-based cotton leaf disease detection methods,a cotton leaf disease detection method based on improved SSD was proposed by combining the characteristics of cotton leaf ***,the lightweight network MobileNetV2 was introduced to improve the backbone feature extraction network,which provides more abundant semantic information and details while significantly reducing the amount of model parameters and computing complexity,and accelerates the detection speed to achieve real-time ***,the SE attention mechanism,ECA attention mechanism,and CBAM attention mechanism were fused to filter out disease target features and effectively suppress the feature information of jamming targets,generating feature maps with strong semantics and precise location *** test results on the self-built cotton leaf disease dataset show that the parameter quantity of the SSD_MobileNetV2 model with backbone network of MobileNetV2 was 50.9%of the SSD_VGG model taking VGG as the *** with SSD_VGG model,the P,R,F1 values,and mAP of the MobileNetV2 model increased by 4.37%,3.3%,3.8%,and 8.79%respectively,while FPS increased by 22.5 frames/*** SE,ECA,and CBAM attention mechanisms were introduced into the SSD_VGG model and SSD_MobileNetV2 *** gradient weighted class activation mapping algorithm to explain the model detection process and visually compare the detection results of each *** results indicate that the P,R,F1 values,mAP and FPS of the SSD_MobileNetV2+ECA model were higher than other models that introduced the attention ***,this model has less parameter with faster running speed,and is more suitable for detecting cotton diseases in complex environments,showing the best detection ***,the improved SSD_MobileNetV2+ECA model significantly enhanced the semantic information of the shallow feature map of the model,and has a goo

关键词： cotton disease detection SSD MobileNetV2 attention mechanism

Numerical simulation of the 3D flow field in a ring die pellet mill considering viscous heating

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第3期11卷 135-153页

作者： Yong-Mei Wang Xiao-Peng Huang Jin-Feng Wu Wan-Xia Yang college of mechanical and electrical engineering gansu agricultural university Lanzhou 730070P.R.China

Viscous heating has a substantial influence on the extrusion forming process and product quality of powder *** study selected the MUZL420 ring die pellet mill as the research object,from which a 3D flow physical model was *** numerical simulation of 3D nonisothermal flow in the extrusion pelletizing process of granulated alfalfa was performed with *** distribution laws of pressure,velocity,shear rate,viscosity,viscous heating and temperature in the flow field were revealed to thoroughly investigate the pelletizing process and provide a reference for structural optimization and process *** results showed that two extrusion zones in the pelleting chamber were symmetrical with respect to the center,and the significant pressure gradient along the rotating direction of the ring die and the roller caused the material to flow back in the opposite *** were larger velocity gradients,shear rates and viscous heating levels in the deformation and compaction zone,the negative pressure zone behind the extrusion zone and the die *** distribution of viscosity was opposite to that of the shear *** temperature increase area caused by viscous heating gradually expanded from the material inlet to the bottom of the extrusion chamber along the Z-axis direction,and the temperature increased *** extrusion force and the forming temperature in the extrusion forming zone were captured in the numerical *** extrusion forming density was calculated with the regression prediction model established through the simulation experiment of pelletizing with a ring *** a comparison with the results of mean alfalfa pellet density from the ring die pellet mill experiment,the relative error was less than 5%,which indicated that the numerical simulation method was reliable.

关键词： Ring die pellet mill viscous heating 3D flow field numerical simulation

Mechanism analysis and performance improvement of mechanized ridge forming of whole plastic film mulched double ridges

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International Journal of agricultural and Biological engineering 2020年第5期13卷 107-116页

作者： Fei Dai Xuefeng Song Wuyun Zhao Ruijie Shi Fengwei Zhang Xuekun Zhang gansu Provincial Key Laboratory of Aridland Crop Science Gansu Agricultural UniversityLanzhou 730070China college of mechanical and electrical engineering Gansu Agricultural UniversityLanzhou 730070China

In order to achieve high-performance and mechanization construction standard of whole plastic mulched double ridge seedbed,and to meet its forming process and corresponding agronomic requirements of the mechanized double ridge seedbed,the key working parameters such as the speed of rotary blade group,the thickness of upturned sod and the power consumption of rotary blade group under different parameters were analyzed based on related working performance in ridge ***,the test factors and their range of values were finally determined in this *** element method(DEM)simulation was applied in the numerical simulation of the mechanized ridge forming process of whole plastic mulched double ridges,and the ridge forming effect and digging resistance variation characteristics of different types of shovels were *** the forward speed of the combined machine,the penetration angle of the arc-shaped shovel and the depth of rotary tillage as independent variables,and the qualified rate of seedbed tillage as the response value,the mathematical model between the test factors and the qualified rate of the seedbed tillage was established,to explore the influence sequence of the factors on the qualified rate of seedbed tillage,and obtained the following optimal working parameters of the ridge forming device:the advancing velocity of the combined machine of 0.50 m/s,penetration angle of the arc-shaped shovel of 31°,rotary tillage depth of 140 mm,and average qualified rate 95.20%of seedbed tillage in corresponding simulation verification *** test showed that the average qualified rate of seedbed tillage in ridge forming device was 93.60%,which was close to that of the simulation *** actual working condition of the sample machine was basically in line with the simulation process and could relatively precisely reflect the mechanized ridge forming mechanism of whole plastic double *** results showed that the established DEM model and its

关键词： whole plastic film mulched double ridges mechanized ridge forming DEM numerical simulation parameter optimization

Numerical simulation and analysis of mechanized suppression process of seedbed with whole plastic film mulching on double ridges

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International Journal of agricultural and Biological engineering 2021年第1期14卷 142-150页

作者： Fei Dai Xuefeng Song Wuyun Zhao Bugong Sun Ruijie Shi Yang Zhang college of mechanical and electrical engineering Gansu Agricultural UniversityLanzhou 730070China gansu Provincial Key Laboratory of Aridland Crop Science Gansu Agricultural UniversityLanzhou 730070China

In order to achieve the construction standard of high mechanized performance of the seedbed with whole plastic-film mulching on double ridges,in this study,the forms of suppression failure were analyzed,and the key factors influencing the suppression performance were determined based on the structure of the seedbed suppression device and its working *** discrete element method was adopted for numerical simulation on the suppression process of the seedbed with whole plastic film mulching on double ridges;the parameters during the interaction between the suppression device and seedbed soil were extracted and analyzed,such as contact area,sinkage and horizontal traction resistance trend of press wheels on big ridges and furrows of small *** the suppression load on big ridges,suppression load on furrows of small ridge,and advancing velocity of the combined operation machine as the independent variables,qualified rate of suppression as the response value,a mathematical model between the test factors and qualified rate of suppression was established,to explore the influence sequence of the factors on suppression qualified *** optimal working parameters of the suppression device were finally obtained:the suppression load on big ridges was 40 N,suppression load on furrows of small ridge was 69.8 N and the machine advancing velocity was 0.98 m/s,and the achieved mean value of suppression qualified rate was 92.6%.Field verification test showed that the mean value of suppression qualified rate was 90.3%,a mere difference of 2.3%compared with the simulation *** actual operation of the sample machine was basically consistent with the simulation process and could reveal the mechanized suppression operation mechanism of the seedbed with whole plastic film mulching on double ridges,indicating that the established DEM model and its parameter setting were relatively accurate and reasonable.

关键词： seedbed whole plastic film mulching double ridges mechanized suppression discrete element method numerical simulation parameter optimization

Determination of the coefficient of rolling friction of irregularly shaped maize particles by using discrete element method

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International Journal of agricultural and Biological engineering 2020年第2期13卷 15-25页

作者： Linrong Shi Wuyun Zhao Bugong Sun Wei Sun School of mechanical and electrical engineering Gansu Agricultural UniversityLanzhou 730070China

The coefficient of rolling friction is a foundation parameter for conducting particles simulation,however,which of irregularly shaped maize seeds is difficult to ***,the coefficient of rolling friction between the simulation particles and the actual seeds is inconsistent due to the shaped difference of model and different position of gravity *** paper use two methods to determinate the coefficient of rolling friction based on discrete element method(DEM)and physical *** types of maize models from five different shaped maize samples(including horse-tooth shape,spherical cone shape,spherical shape,oblate shape,irregular shape)were developed with the help of slice modeling and 3D modeling *** cylinder container is used to arrange the simulation experiments of angle of repose with taking the coefficient of rolling friction as independent variables and the simulation angle of repose as target *** predicting detailed the coefficient of rolling friction(including horse-tooth shape,spherical cone shape,spherical shape,between horse-tooth shape and spherical cone shape,between horse-tooth shape and spherical shape,between spherical shape and spherical cone shape maize models),and forecasting a unified the coefficient of rolling friction among horse-tooth shape,spherical cone shape and spherical shape maize models,two types of materials(aluminum cylinder container and organic glass container)were used to validate the difference the angle of repose between the simulation maize models and actual maize *** show the relative error of the angle of repose between the maize models controlled by the coefficient of rolling friction through the detailed method and the actual maize seeds is 0.22%,0.33%in aluminum cylinder,organic glass container,*** relative error of the angle of repose between the simulation maize models controlled by the coefficient of rolling friction through the united method and a

关键词： coefficient of rolling friction maize irregularly shaped model angle of repose discrete element method

Determination and analysis of basic physical and contact mechanics parameters of quinoa seeds by DEM

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International Journal of agricultural and Biological engineering 2023年第5期16卷 35-43页

作者： Linrong Shi Wuyun Zhao Bugong Sun Wei Sun Gang Zhou college of mechanical and electrical engineering Gansu Agricultural UniversityLanzhou 730070China Institute of Dryland Agriculture Gansu Academy of Agricultural SciencesLanzhou 730070China

Quinoa is an ancient crop that is nutritious,balanced,and suitable for most ***,it has not been known and sought by the public until modern *** recent years,quinoa has been intensively known and widely grown in *** mechanized production machines have also been *** the help of DEM,we design and optimize the quinoa combined seeder,improving seeding efficiency and *** this paper,the basic physical and contact mechanics parameters required for the Hertz-Mindlin(no slip)of quinoa seeds in EDEM software were *** coefficient of rolling friction of quinoa seeds was calibrated on DEM,and which of Long Quinoa 4 is 0.043,and that of Meng Quinoa 4 was ***,we can find that the coefficient of rolling friction strengthens the shape to restrict rolling and weakens the shape to increase *** above research provides simulation parameters for the design and optimization of quinoa seed seeding machinery.

关键词： quinoa seeds physical parameters contact parameters calibration DEM

Fault Diagnosis Based on BP Neural Network Optimized by Beetle Algorithm

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Chinese Journal of mechanical engineering 2021年第6期34卷 252-261页

作者： Maohua Xiao Wei Zhang Kai Wen Yue Zhu Yilidaer Yiliyasi college of engineering Nanjing Agricultural UniversityNanjing210031China college of mechanical and electrical engineering Xinjiang Agricultural UniversityUrumqi830052China

In the process of Wavelet Analysis,only the low-frequency signals are re-decomposed,and the high-frequency signals are no longer decomposed,resulting in a decrease in frequency resolution with increasing ***,in this paper,firstly,Wavelet Packet Decomposition is used for feature extraction of vibration signals,which makes up for the shortcomings of Wavelet Analysis in extracting fault features of nonlinear vibration signals,and different energy values in different frequency bands are obtained by Wavelet Packet *** features are visualized by the K-Means clustering method,and the results show that the extracted energy features can accurately distinguish the different states of the *** a fault diagnosis model based on BP Neural Network optimized by Beetle Algo-rithm is proposed to identify the bearing *** with the Particle Swarm Algorithm,Beetle Algorithm can quickly find the error extreme value,which greatly reduces the training time of the *** last,two experiments are conducted,which show that the accuracy of the model can reach more than 95%,and the model has a certain anti-interference ability.

关键词： Rolling bearing BP neural network Beetle algorithm Wavelet packet transform

Efficient one-pot synthesis of n-butyl levulinate from carbohydrates catalyzed by Fe_2(SO_4)_3

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Journal of Energy Chemistry 2017年第3期26卷 556-563页

作者： Ran An Guizhuan Xu Chun Chang Jing Bai Shuqi Fang School of Chemical engineering and Energy Zhengzhou University college of mechanical and electrical engineering Henan Agricultural University

Butyl levulinate（BL） is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe（SO）was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose, inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe（SO）, showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe（SO）was studied by characterizing them using powder X-ray diffraction（XRD）, scanning electron microscope（SEM）, X-ray photoelectron spectroscopy（XPS）. A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass.

关键词： One-pot n-butyl levulinate Metal sulfate Carbohydrates