INMATEH - Agricultural Engineering

21-36

Authors: Ping ZHAO, Tiankuo YU, Guofa XU, Ruijin GUO, He LI, Hongfei XU, Tianci JIN, Dong JI

Taking into account the physicochemical properties of soil and the complexity of adhesion interface, how to improve the soil adhesion on the mechanical surface is a crucial technical issue. In order to lower the increasing resistance caused by soil adhesion on the surface of a digging shovel in potato harvesting, a potato digging shovel with a non-smooth surface structure was designed based on bionics theory. Based on testing physical and mechanical properties of soil, a soil groove model corresponding to soil physical properties and particle model physical properties was established through a combination of simulation and physical tests, and a simulation test for evaluating the drag reduction performance was conducted. The simulation comparison test results show that the performance of the bionic digging shovel is better than that of the traditional potato digging shovel, regardless of whether the broken soil rate or the working resistance is reduced, and the soil adhered to the mechanical surface can be effectively reduced by 93.3%. The research results can provide ideas and methods for solving the adhesion problem between machinery and soil.

46-56

Authors: Junming HOU, Zhaotan REN, Hongjie ZHU, Zhi RENDE, Wei WANG

Castor is one of the important oil crop, the shelling process of which directly affects the quality of castor seeds. In the process of shelling, the shelling force of castor is an important index to study its damage. The castor capsule model was established and the shelling test machine was established based on the discrete element method. Then the extrusion law of castor capsule during shelling was analyzed. The shelling process is divided into three stages, which are the Initial stage, stable shelling stage and the final stage. The force law of shelling process is analyzed. The results show that with the increase of rotating speed, the maximum force decreases from 68.78 to 68.10 N, the maximum speed increases from 8.92 to 12.99 m/s, the force of inner drum increases from 509.34 to 533.14 N, and then decreases to 456.15 N. The shelling increases from 91.23% to 91.28%, and then decreases to 88.89%. With the increase of filling amount, the maximum force increases from 55.86 to 76.93 N, the maximum speed decreases from 12.99 to 10.86 m/s, the force of inner drum increases from 338.58 to 603.364 N, and the shelling rate changes from 91% to 90.05%. This study can provide theoretical support for the design of castor shelling machine.

66-75

Authors: Andrés Rodríguez Toscano, Rafael Ramirez, José M. Sánchez

This research presents a thermodynamic analysis of a Thermal LTC-10 single-effect absorption series cooling system using the water/LiBr pair. Four operating scenarios were modeled on an hourly basis (24h) with EES software using mass and energy balances and the environmental conditions of the city of Barranquilla, Colombia. The analysis of the results shows that the system powered only by solar energy obtains the highest COP between 8:00 and 16:00 hours and the lowest greenhouse gas (GHG) emissions, while the system powered by rice husk biogas presents stable operation throughout the day and higher SO2eq emissions.

86-95

Authors: Hongwen YAN, Zhiwei HU, Yiran LIU

To explore the application of traditional machine learning model in the intelligent management of pigs, in this paper, the influence of the PCA pre-treatment on pig face identification with KNN is studied. With testing method, individual identification test was carried out on 10 different pigs in two testing schemes, in which one adopted KNN alone and the other adopted PCA + KNN, for which the classifier parameter was taken as 3 and 5, respectively. In the optimized scheme, the operating efficiency got significantly increased, also the training time and testing time were reduced to 4.8% and 7% of the original value in the KNN alone scheme, though the accuracy got lowered to a certain extent. With all these factors taken into consideration, PCA pre-treatment is beneficial to individual pig identification with KNN. It can provide experimental support for mobile terminals and embedded application of KNN classifiers.

107-116

Authors: Bin WANG, Hua YANG, Lili LI

In order to realize the rapid and accurate identification of different maturity of Cerasus humilis fruit, this study explored the nondestructive testing method of Cerasus Humilis fruit maturity based on hyperspectral imaging technology. The hyperspectral data of 320 samples of Cerasus humilis fruit were collected by using a hyperspectral imaging system in the range of 895~1700 nm. By comparing the prediction accuracy of the partial least squares (PLS) model established by four preprocessing methods, the competitive adaptive reweighted algorithm (CARS), successive projection algorithm (SPA), and random frog (RF) were used to extract characteristic wavelengths, and partial least squares-discriminant analysis (PLS-DA) and least squares-support vector machine (LS-SVM) discriminant models were established. The results showed that the SPA-LS-SVM model had the highest discrimination accuracy for the four types of maturity samples, and the discrimination accuracy of the correction set and prediction set were 85.00% and 87.50%, respectively. This study provides a theoretical reference for the rapid and nondestructive testing of the maturity of Cerasus Humilis fruit by hyperspectral imaging technology.

127-136

Authors: Jingxin SUN, Liqin YANG, Baohui XU, Yuming GUO

In order to meet the precision seeding of small seeds including millet and broomcorn millet in hilly and mountainous areas, a single-row small grain precision seeder was developed. Static seeding test and seeding test were carried out on the seeder. In this paper, the key parts such as socket wheel-ring groove seed metering device, transmission system and tensioning wheel are designed. The working parts such as arrow shovel furrow opener, plastic seed tube and hollow cast iron press wheel were selected to achieve seed metering. The seed metering wheel has double-row of holes. The results of static seeding test showed that rotational speed had a significant effect on the sowing quantity of millet and broomcorn millet (P < 0.001). The higher the rotational speed, the greater the sowing quantity. With the increase of rotational speed of seed metering wheel, the damage rate of millet and broomcorn millet increased. At the same rotational speed, the breakage rate of broomcorn millet is smaller than that of millet. The field sowing test showed that when the seeder is at a marching speed of about 0.5 m/s, the qualified rate of the hole spacing of millet and broomcorn millet is greater than or equal to 90%, and the qualified rate of the number of grains per hole is greater than or equal to 82%. All indicators meet the requirements of the technical conditions of single-grain (precision) seeder. The design can provide reference for the design and optimization of small grain precision seeder.

147-154

Authors: Mariana- Gabriela MUNTEANU, Gheorghe VOICU, Gabriel-Alexandru CONSTANTIN, Elena –Mădălina STEFAN, Paula TUDOR, Mihaela NITU

This paper presents an analysis of the variation of energy consumption in the lamination and drawing process of bagel doughs. Also, the paper highlights the farinographic characteristics (water absorbtion, dough develpomnet time, dough stability, degree of dough softening and farinographic index) of the floour used for the dough preparation for which the energy consumption during lamination and drawing was determined

165-172

Authors: Wenhao DOU, Sanmin SUN, Pengxiang XU

This paper evaluates linear regression analysis, BP neural network, and a random forest prediction model for the prediction of jujube water demand. The results highlight that the R2 of the random forest is 0.941 and the residual distribution is the most stable. Hence, the random forest is more suitable for prediction, and therefore, an intelligent irrigation system is established employing random forest, where the cloud server is the upper computer and a Raspberry Pi is the lower computer, and at the same time, a PC and a mobile interface was built to present various information about the developed irrigation system.

181-190

Authors: Juan LIU, Zhuoyu YAN, Mingze XU, Yudi LIU, XueWei BAI, Yonghai XIU, DeSheng WEI

Coconut coir dust and corn stover powder were taken as raw biomass materials for pellet production, using four uni-axial compression set-ups, to explore the influence of the diameter of the inner hole diameter of the cylinder, the depth in compression , and the depth remained in compaction on the pellet density. Sample of pellets produced at the force steady phase, the maximum pellet density of the coconut coir dust material is 1.53 g/cm3 (1530 kg/m3), and 1.23 g/cm3 (1230 kg/m3) of the corn stalk powder pellets are obtained, At the same time, in the process of the test, Failure to compress the two biomass raw materials into pellets also occurred, indicating that the compression parameters studied in the experiment had a significant impact on the pellet quality. On the basis of the obtained pelleting test data, taking into account the nonlinear characteristics between pellet density and processing parameters involved, the adaptive neuro-fuzzy influence system(ANFIS) method was used to predict the pellet density of coconut coir dust and corn stover powder. The results show that the method is effective for predicting the density of biomass particles.

201-210

Authors: Tomasz ŻELAZIŃSKI, Adam EKIELSKI, Karol DURCZAK, Magdalena MORAWSKA

The paper presents the results of research on film biocomposites made of thermoplastic starch (TPS) and various types of nut shells. The research involved the use of thermally treated nut shells: hazelnuts, pistachios, walnuts and peanuts. TPS biocomposites were produced by the pour method using non-adherent moulds. The obtained samples were used to test the basic physical properties used in testing biodegradable materials. The following parameters were determined: mechanical strength, colour and colour difference, water contact angle, moisture absorption from water and atmospheric air. Images of biocomposite fractures were also taken using a scanning electron microscope (SEM). It was found that the addition of nut shells enabled the production of homogeneous materials and contributed to the improvement of their strength parameters. The research showed that nut shells can be a prospective raw material for the production of innovative biodegradable materials.

221-231

Authors: Xin WANG, Guohai ZHANG, Jia YAO, Jitan LIAN, Xining YANG

The corn grain harvester serves as an example of complex farming machinery with a condition monitoring system that collects a lot of working condition data, making it challenging to identify the true change pattern due to the data coming from the equipment in various states. Firstly, the overall structure of the corn grain harvester is analyzed, and the common causes and mechanisms of corn grain harvester failures are analyzed, leading to the cutting table as the main research object; Secondly, by collecting historical failure data of corn grain harvester as well as real-time failure information for collation and pre-processing, eliminating interference such as noise and missing data, establishing a failure matrix, extracting internal characteristics between failure causes and establishing a mapping between failure causes and failure phenomena; Finally, the future failure phenomena of the corn grain harvester are predicted according to different failure causes. The simulation analysis results show that the self-coding neural network fault prediction model can better predict the occurrence probability and types of faults and provide data support for fault maintenance and decision making of agricultural machinery.

239-250

Authors: Qichao LI, Jinlong FENG, Xianglan MING

In order to improve the opener of the seeder and its lightweight structure, a new type of opener is designed. The overall structure and working principle of a single-ditch double-row opener are analyzed, and the structural parameters of machete cutting soil and the soil guide board are designed and optimized. Using the penetration angle of machete cutting soil and the included angle of the soil guide board as test factors, field experiments were conducted. As the test indexes, the working resistance, the sowing coefficient of variation, and the depth coefficient of variation were used to analyze the effect of the opener. The results showed that in terms of working resistance, the penetration angle of the machete cutting edge and the included angle of the soil guide board were extremely significant, and the included angle was greater than the penetration angle regarding the influence degree. In terms of the sowing coefficient of variation, the penetration angle was significant, and the included angle was extremely significant. Regarding the depth coefficient of variation, the penetration angle was extremely significant, and the included angle of the guide soil board was significant. Based on the optimization analysis by using the Design Expert 8.0.6, it is found that the performance of the opener is optimal when the penetration angle and the included angle are 50.03° and 42.36°, respectively. The working resistance, the sowing coefficient of variation, and the depth coefficient of variation are 61.47N, 6.49% and 4.22%, respectively. After verification, the results are basically consistent, and the seeding and trenching performance meets the agronomic requirements. This study can provide a basis and technical reference for the design and development of the ditching technology and opener.

265-274

Authors: Yun LIU, Weiran LV, Lihong LI, Bing XU, Decong ZHENG, Qi LU

In order to fully explore the influence of different pressure methods on the growth characteristics of buckwheat, a pressure test device with adjustable press force, and easy to replace the press wheel was designed. Using the dry matter quality of buckwheat roots, stems, leaves at seedling stage, plant height, number of main stem nodes, number of main stem branches, grain number per plant, grain weight per plant, and yield as evaluation indexes, single factor test on press force was carried out, and three-factor and three-level orthogonal test was carried out too with press wheel outer diameter, press force and press wheel type as factors. The results showed that the index values of buckwheat showed a trend of first increasing and then decreasing with the increase of press force. When the press force was 450 N, the growth and development of buckwheat performed best. The effects of press wheel outer diameter, press force, and press wheel type on growth characteristics of buckwheat was different. The effects of press force and press wheel type on the indexes were greater than that of press wheel outer diameter. The optimal pressure methods of buckwheat sowing are as follows: the press wheel outer diameter is 300 mm, the press force is 450 N, and the press wheel type is conical combined wheel. The results of this study could provide reference for the improvement of high-yield mechanized sowing technology of buckwheat and the design of rational pressure device.

287-298

Authors: Tianhua LI, Siqi ZHANG, Chaofan ZHANG, Guanshan ZHANG, Min WEI, Hongen GUO, Guoying SHI

This paper proposes a fertilizer mixing device that combines pressure relief return and mechanical agitation to address the issues in the current water-fertilizer integration equipment related to limited fertilizer mixing methods and inconvenient irrigation pressure regulation. The device employs different mixing modes for various fertilizer forms and uses pressure relief return to adjust irrigation pressure, thereby enhancing the efficiency of water-fertilizer mixing and optimizing energy consumption. The experimental results indicate that the reflux mode is suitable for liquid-type fertilizers which are fast dissolving and easy to diffuse, and its EC value is stable at about 6.60 mS/cm, which is close to the calibrated value of 6.80 mS/cm. The stirring paddle mode compensates for the reflux mode's weak mixing effect, making it suitable for solid powder-type fertilizers' mixing operation. The EC value remains stable at approximately 8.60 mS/cm when calibrated at 8.70 mS/cm. The “stirring paddle + two-way reflux” mode demonstrates the most robust mixing effect and is suitable for mixing solid granular fertilizers. When calibrated at 8.20 mS/cm, it stabilizes at approximately the calibration value after 105 s. This research provides technical support and a theoretical basis to accomplish efficient, energy-saving, and rational application of water-fertilizer integration across diverse fertilizer forms.

309-319

Authors: Huang TIANYI, Florentina BADEA, Xiao MAOHUA, Zhao SHANHU, Sorin-Ionut BADEA, Cristian-Radu BADEA

In order to solve the real-time obstacle avoidance problem in electric tractor operation, an improved dynamic window approach (DWA) based on optimal energy consumption is proposed for electric tractor obstacle avoidance. Firstly, energy consumption model of tractor is established based on the transmission system of electric tractor, then energy consumption evaluation sub-function is introduced to improve the evaluation function of original DWA algorithm, and finally, the trajectory is evaluated and the optimal solution of the trajectory is determined by using new evaluation function. Based on the kinematics model of YL254ET electric tractor in Yancheng Yueda, a model predictive controller is designed. The obstacle avoidance planning and tracking control of electric tractor are simulated jointly on Simulink and CarSim simulation platform. Finally, the obstacle avoidance planning test is carried out. The simulation and experimental results show that after the algorithm improvement, the energy consumption of electric tractors is reduced, the generated path is smoother, and the lateral error is smaller.

328-336

Authors: Bing XU, Qingliang CUI, Decong ZHENG

Aiming at the poor efficiency in crushing a handful of caking organic fertilizers spraying from the traditional disc spreader, an improved disc spreader equipped with spike-tooth crushing unit was designed with the introduction of its structural composition and working principle. Also simulation experiments were carried out based on the discrete element method according to the solutions made before and after the structural improvement. Firstly, a granular organic fertilizer model was established based on the EDEM and a caking organic fertilizer bonding model was built based on the HMB (Hertz-Mindlin with bonding) contact model. Then two organic fertilizer spreading models corresponding to the solutions were respectively established, based on which simulation experiments were repeated three times on the spreading process. The analysis on the particle velocity vector diagram revealed the interaction relationship between organic fertilizers with the toothed shaft, external wall and disk, verifying the crushing mechanism of crushing unit. By calculating the total number of the bonds generated and broken in the spreading process in both of the spreading models, the average broken rate of bonds in the spreading process was separately 58.87% and 98.05% based on each solution, revealing that the improved solution outperformed the traditional solution in terms of the efficiency in crushing the caking organic fertilizers. This research will be a reference in designing the critical components or improving the overall performance of disc spreader.

350-358

Authors: Volodymyr BULGAKOV, Semjons IVANOVS, Volodymyr KUVACHОV, Lucretia POPA, Igor SIVAK, Oleksandra TROKHANIAK, Yevhen IHNATIEV

An important operational indicator of agricultural machine-tractor units is the smoothness of movement, which significantly affects the traction and dynamic performance of their work, productivity, agronomic qualities of the operation, traffic safety, durability and efficiency. As a rule, it is evaluated by the influence of oscillations (translational vertical, transverse, angular longitudinal, etc.), on these indicators, as well as on the physical condition and health of operators who control these units in real production conditions. This article presents an improved method and results of experimental assessment of the smoothness of the movement of the modular agricultural unit, which moves in the footsteps of a constant technological track. Studies of the smoothness of the modular unit showed that the graphs of normalized correlation functions of vertical oscillations of the modular agricultural tool developed by us in its motion in the wake of a constant techno-logical track is characterized by a function containing along with random components harmonic, which are expressed by attenuating periodic oscillations. The range of frequencies of oscillations of the frame of the agricultural tool is concentrated in the range from 0 tо 20 s−1, which is consistent with the frequency range 0…0.3 s−1 in which the variances of oscillations of inequalities of a profile of traces of a technological track are concentrated. Studies have confirmed the effectiveness of the method of estimating the intensity of vertical oscillations of the agricultural unit measuring and recording system based on a tablet computer with Android operating system with built-in accelerometer sensors and Accelerometer Meter application. The developed technique of mathematical modelling and experimental determination of vertical oscillations of the machine-tractor unit can be used in the study of the dynamics of other agricultural machines and units.

369-378

Authors: Changqing LIU, Jinheng GU, Xin DU, Chengwen LIU, Yuefeng DU, Enrong MAO

The accuracy of tractor plowing is an important link to ensure the quality of agricultural crops. The integrated control of draft-position in plowing is an effective plowing precision control technology which can be used to improve the tractor's plowing efficiency. The hydraulic system of the tractor hitch has the characteristics of large load and complex working environment. A differential and integral sliding mode adaptive controller (DI-SMAC) is designed for the tractor hitch hydraulic system with strong nonlinearity, uncertainty and time-varying parameters. Compared with the traditional PID controller, integral sliding mode adaptive controller(I-SMAC) and differential and integral sliding mode adaptive controller(DI-SMAC) in the electro-hydraulic hitch control system, the numerical simulation verifies the advantages of the differential and integral sliding mode adaptive controller. The real test platform of the agricultural tractor is built. The test results show that the DI-SMAC can realize the integrated control function of draft-position. In the position control mode, there is no static error, and the anti-interference ability is strong; Under the draft control mode, compared with the traditional PID controller, the range of traction error of differential and integral sliding mode controller is reduced by 32.9%, and the standard deviation is reduced by 38.6%; When the weight coefficient is changed, the traction force and tillage depth fluctuation are different with different weight coefficients. It shows that the DI-SMAC is stable and effective, and the developed method is expected to provide technical support for the fine plowing operation of tractors.

391-400

Authors: Xin DU, Changqing LIU, Xuhui LI, Wei ZHU, Qixin SUN, Shufa CHEN

To ensure accurate and consistent fertilizer application, the key component of the fertilizer feeding device, the grooved wheel, was designed and theoretically analyzed, and the number of grooves of the fertilizer wheel was determined to be 9. The effects of grooves inclination angle, grooves length and operating speed on the fertilizer feeding performance were analyzed by single-factor tests, and the appropriate range of factors was determined. The effect of the interaction between groove length and operating speed on the amount of fertilizer discharged from the groove was investigated by a full factorial test, and a quadratic regression was fitted to the test results to establish the regression equations of groove length and operating speed on the average fertilizer application per groove and the coefficient of variation of the average fertilizer application per groove, which can be used to predict the average fertilizer application per groove and the coefficient of variation of the average fertilizer application per groove to solve for groove length and operating speed.

415-422

Authors: Dimitar GEORGIEV, Galina DINEVA, Dimitar KARASTOYANOV, Kancho PEYCHEV, Vania DIMOVA

The hourly productivity of the milking parlour is significantly influenced by the organization of the technological process. Milkers perform a series of sequential operations (entry on the platforms, washing, drying, placing the milking units, removing them, disinfecting the teats, exiting the platforms of the milking parlour) the duration of which is a large part of the total milking time. The duration of the latent period from the release of oxytocin to its contact with the myoepithelial cells in the glandular part of the udder is from 30 s to 90 s (average 60 s). In this line of thought, the following questions arise: "in what time interval should the preparatory operations for milking be performed and what is their permissible duration". The aim of the present study is to develop methodologies (models) for simulating the work of milkers in "Parallel" type parlours. It was found that under the initially set working conditions of only two milkers in the milking parlour, all developed models are applicable for capacities up to 2x8. Models II, III and IV are unacceptable for capacities above 2x8, as the total duration of preparation of milking cows exceeds the time frame by between 30-80%. This finding proves that for a capacity over 2x8 it is necessary to perform technological operations with a larger number of milkers.

431-440

Authors: Shibang MA, Ailing GUO

Soluble solid content (SSC) is a major quality index of kiwifruits. Visible near-infrared (Vis/NIR) hyperspectral imaging with the genetic algorithm (GA) was adopted in this study to realize the non-destructive prediction of kiwifruit SSC. A laboratory Vis/NIR hyperspectral imaging system was established to collect the hyperspectral imaging of 120 kiwifruit samples at a range of 400–1100 nm. The average reflectance spectral data of the region of interest of the kiwifruit hyperspectral imaging were obtained after different preprocessing method, namely, Savitzky–Golay smoothing (SG), multiplicative scatter correction (MSC), and their combination method. The prediction models of partial least squares regression, multiple linear regression, and least squares support vector machine (LS-SVM) were built for determining kiwifruit SSC by using the average reflectance spectral data and effective feature wavelength variables selected by GA, respectively. The results show that SG+MSC is the best preprocessing method. The precisions of the prediction models built using the effective feature wavelength variables selected by GA are higher than that established using full average reflectance spectral data. The GA-LS-SVM prediction model has a best performance with correlation coefficient for prediction (R=0.932) and standard error of prediction (SEP=0.536° Bx) for predicting kiwifruit SSC. The prediction accuracy has been improved by 5.6% compared with that of the prediction models established by using the full-band reflectance spectral data. This study provides an effective method for non-destructive detection of kiwifruit SSC.

455-467

Authors: Zhen WANG, Keqing QIAN, Xiaoli ZHU, Xinyu HU, Xinran LI

With the rapid development of agricultural machinery intelligence and informatization, agricultural robots are becoming the protagonist, promoting standardized production in agriculture, improving efficiency, and reducing labor costs. However, how to quickly plan an efficient and safe path for agricultural transport robots is currently a hot topic in path planning research. In this study, the path optimization problem of agricultural robots handling agricultural products (such as Edible Fungi) in and out of warehouses, which served as the study object, was solved. First, the number of agricultural handling robots was initialized based on the scanning method, and the geometric center of sub-path nodes was set as the virtual node. Secondly, the optimal path of the virtual node was solved using the improved ant colony algorithm embedded with a genetic operator, and the optimal result of sub-paths was acquired. Thirdly, the optimal solution meeting constraint conditions was obtained with the launch cost, transportation cost, and time cost of agricultural robots as objective functions. Lastly, the effectiveness of the optimization model and the improved ant colony algorithm was verified through the instance analysis. This study is of certain significance to the ex-warehousing path optimization of agricultural robots under the sustainable development concept of agricultural automation.

477-486

Authors: Muhammad Nashir EFFENDY, Siti NURHASANAH, Asri WIDYASANTI

Desiccated Coconut (DC) is a product rich in fat, protein, carbohydrates and fiber. It is widely used as an additive for the snack industry. As a potential food additive product, every process needs to be considered to produce a good quality DC. The effort to maintain the quality of DC is to optimize the main process of making DC, namely the drying process. In several studies, the drying condition of DC was carried out differently, that is why an optimization process on DC drying is needed. This study aims to determine the temperature and drying time combination that produces DC with the optimum moisture content, fat content, and yield. The drying process used a food dehydrator with a temperature combination of 50°C to 70°C and a time of 2 to 4 hours. The research method used was a laboratory experimental method with Response Surface Methodology (RSM) optimization using Central Composite Design (CCD). It was presented that the optimum drying conditions given by RSM were obtained by drying at 70°C for 2 hours. The results obtained from the validation of a water content of 1.279% wet basis (wb), a fat content of 64.855% wb, and a yield of 42.363%, were following CODEX STAN 177-1991. Based on this study, it can be concluded that the combination of temperature and drying time affects moisture content, fat content, and DC yield.

497-506

Authors: Man CHEN, Gong CHENG, Jinshan XU, Guangyue ZHANG, Chengqian JIN

In this study, an online detection system of soybean crushed rate and impurity rate based on DeepLabV3+model was constructed. Three feature extraction networks, namely the MobileNetV2, Xception-65, and ResNet-50 models, were adopted to obtain the best DeepLabV3+model through test analysis. Two well-established semantic segmentation networks, the improved U-Net and PSPNet, are used for mechanically harvested soybean image recognition and segmentation, and their performances are compared with the DeepLabV3+ model’s performance. The results show that, of all the models, the improved U-Net has the best segmentation performance, achieving a mean intersection over union (FMIOU) value of 0.8326. The segmentation performance of the DeepLabV3+ model using the MobileNetV2 is similar to that of the U-Net, achieving FMIOU of 0.8180. The DeepLabV3+ model using the MobileNetV2 has a fast segmentation speed of 168.6 ms per image. Taking manual detection results as a benchmark, the maximum absolute and relative errors of the impurity rate of the detection system based on the DeepLabV3+ model with the MobileNetV2 of mechanized soybean harvesting operation are 0.06% and 8.11%, respectively. The maximum absolute and relative errors of the crushed rate of the same system are 0.34% and 9.53%, respectively.

517-526

Authors: Tiangang HOU, Zhenyu WANG, Mingce ZHAO, Cuihong LIU, Mingjin XIN, Liyan WU, Benhua ZHANG

In this study, the effects of different electric field parameters on the germination characteristics of aged rice seeds were determined via low-frequency high-voltage pulsed electric field (LH-PEF) treatment. The Design-Expert software was used to design a rotating combination test, and response surface analysis was used to optimize five germination characteristics of rice seeds. The optimal treatment voltage was 13 kV and the optimal treatment time was 32.72 min. The results show that, under the optimal treatment conditions (P<0.01), the germination potential (GE), germination rate (GP), germination index (GI), vitality index (VI) and high vitality ratio (HVR) of the aged rice seeds increased by 23.7%, 17.7%, 43.2%, 59.7%, and 250%, respectively, compared to the control. The pulsed electric field’s biological effect on the aged rice seeds was the most significant when the optimal treatment parameters were used. The results of this study provide a reliable reference for the parameter optimization of high-voltage electric field treatment of crop seeds.

539-548

Authors: Fazheng WANG, Yaoming LI, Yanbin LIU, Kuizhou JI, Zeng LI, Xiangqian XU, Lei XU

In view of the fact that the threshing gap of combine harvester can only be controlled by adjusting gravure screen and it is time-consuming and laboring, a kind of variable-diameter threshing drum with movable radial plates is developed by changing the diameter of threshing drum to adjust the threshing gap concentrically. All parts of the threshing drum were designed and checked by mechanical design principle, and the statics and modal analysis of the whole structure were carried out by ANSYS Workbench. The results show that the maximum deformation of the variable-diameter threshing drum with movable radial plates is 0.29 mm under boundary conditions. The maximum allowable deformation of the threshing drum in use is 3 mm, which meets the requirements of use. The equivalent stress of the threshing drum with variable diameter is up to 100 MPa, which is less than the yield strength of the material, and will not cause structural damage. According to the modal analysis, the natural frequency of the threshing drum does not cause resonance phenomenon. The field test of wheat was carried out after the processing of the variable-diameter threshing drum with movable radial plates was installed, and the working performance was compared with that of the ordinary drum. The results showed that the threshing performance was the best when the forward speed was 1 m/s, the grain entrainment loss rate was 0.53%, and the grain un-threshed rate was 0.065%. The grain breakage rate is 0.54%, and the performance is more than 50% higher than that of ordinary rollers. It lays a foundation for the adaptive adjustment of threshing gap in combine harvester.

557-559

Authors: Xianmin LIANG, Xiangcai ZHANG, Xingcheng AN, Meng LIU, Xianliang WANG, Zhongcai WEI, Xiupei CHENG, Hui LI

An active-action seeding depth automatic control system was designed , with the purpose of effectively ensure the consistency and stability of the seeding depth when the seeder is operated in the field. Strain-gauge pressure sensor was used in the system, which can detect the force on the tip of the furrow opener in the soil in real time, proceed to the next step judge the change of the seeding depth in the soil according to the change of the pressure signal. In order to achieve consistency and stability of seeding depth, the control signal formation circuit will send a control signal when the pressure on the tip of furrow opener exceeds the appropriate pressure range, and the motor will be controlled to rotate clockwise or counterclockwise to drive the rack and pinion movement to realize the vertical lift of the furrow opener, so that the force on the tip of furrow opener in the soil remains within the appropriate range. The test results indicate that the seeding depth adjustment device based on the tip of furrow opener force measurement has stable and reliable control performance for controlling the seeding depth with an average seeding depth qualification rate of 94.56% and an average seeding depth variation coefficient of only 9.29%, which greatly ensures the consistency and stability of the seeding depth under the condition that the seeding depth is 30-70mm and the working speed is 3-7km/h.

583-592

Authors: Valerian CEREMPEI, Eduard BANARI, Gheorghe POȘTARU, Lucreţia POPA

In the given article, the results of the tribological research of the chrome-gray cast iron coupling are presented, the friction conditions between the cylinder liner and the compression segment being lubricated in various environments are modeled: diesel (control), pure biodiesel B100 and biodiesel-diesel B20 mixture. It was established that the average values of the coefficient of friction in the chrome-gray cast iron coupling, in the case of using biofuels B20, B100 as the lubricating material, are higher in relation to diesel fuel: by 15.6% for B20 and, respectively, by 23.3% for B100. The values of the total wear of the tribological coupling decreased, in relation to diesel, by 36.8% in the case of lubrication with B20 and by 39.5% - with B100.

607-614

Authors: Oana-Diana CRISTEA, Mihaela NITU, Gabriel CONSTANTIN, Mariana MUNTEANU, Oana-Elena MILEA, Roxana ZAHARIA, Marga GRADILA

The working process of the threshing apparatus is characterized by the qualitative working indices they achieve during operation. In order to maximize them with effect on reducing the percentage of seed losses, damaged seeds and impurities in the seed mass, respectively increasing the percentage of separated seeds, certain adjustments can be made on the component elements of a threshing apparatus in accordance with the type, quality and the condition of the material subjected to the threshing operation. In this paper, a n axial flow threshing apparatus was tested under different conditions, in order to be able to obtain the data necessary to adjust the working parameters, which would allow it to be operated at the desired quality indices (losses, injuries and minimal impurities together with separation of seeds from ears and straw almost completely).