Mechanized sugarcane seeding is one of the effective technical measures for improving seeding uniformity and operation efficiency.However,the imperfection of supporting equipment limits the promotion and application o...Mechanized sugarcane seeding is one of the effective technical measures for improving seeding uniformity and operation efficiency.However,the imperfection of supporting equipment limits the promotion and application of this technology.As there are some problems in domestic sugarcane planting machines currently,such as large auxiliary labor,high labor intensity,low seeding uniformity,and large amount of seeds,a disc-type single-bud sugarcane seed metering device was innovatively designed on the basis of the analysis of physical properties of single-bud sugarcane seeds and the combination with agronomic requirements for field planting in this paper.Solidworks was used to simulate and analyze the mechanism,check the theoretical parameters,and process the test prototype.Through single-factor experiments,the effective factors affecting seeding uniformity were determined.A multi-factor orthogonal rotation test was designed,data were collected and then SPSS was used to get the optimal parameters for the seeding uniformity:the advancement speed of machine is 0.22 m/s,the number of disc seeding grooves is 10,the rotating disc speed is 0.18 r/s,and the seeding uniformity is 86.2%;the seeding uniformity was verified by field trial,and the results showed that the average seeding uniformity of the field verification was 83%,with the error 3.2% relative to the optimization result.The relative error is within 10%,indicating that the optimization result is reliable and meets the requirements of seeding uniformity,thus providing theoretical basis for the research and development of the disc-type single-bud seeding device.展开更多
Plot drill has a significant impact on field breeding by replacing manual seeding.However,the seeding performance of plot drill needs to be further improved as the mechanical transmission method cannot work under the ...Plot drill has a significant impact on field breeding by replacing manual seeding.However,the seeding performance of plot drill needs to be further improved as the mechanical transmission method cannot work under the optimal combination of operating parameters.In this study,a cone compartment tray of sowing device was evaluated under the laboratory conditions,using a self-designed seeding control system to adjust the operating parameters.Among them,a plot seeding control system was involved that could set operating parameters through an Android terminal,which effectively reduced the difficulty of parameters adjustment.The method of central composite experiment design was employed to conduct experiments and explore the effects of experiment factors such as lifting height of storage tube(LHST),rotation speed of cone compartment tray(RSCCT),and rotation speed seed distributor(RSSD)on the seeding uniformity coefficient of variation among rows(SUCVR)and the rate of damaged seeds(RDS).For SUCVR of wheat,the results showed that the importance order of main factors from high to low was RSSD,RSCCT and LHST.And for SUCVR of buckwheat,RSCCT had the largest influence,followed by RSSD,and LHST had the smallest influence.For RDS of wheat and buckwheat,only RSSD had a very significant effect among the main factors.The experiments data of wheat indicated that when operated at 27.2 mm for LHST,4.5 r/min for RSCCT and 1169 r/min for RSSD,the sowing performance of wheat was optimal,with SUCVR and RDS values of 5.02%and 0.117%,respectively.The buckwheat seeding performance was found to be optimal when the LHST,RSCCT and RSSD were 26.5 mm,3.9 r/min and 711 r/min,and SUCVR and RDS were 4.74%and 0.113%.The seeding control system realized the electromechanical control of the seeding equipment,was convenient for parameter setting and stepless adjustment,and could be operated under an optimized combination of operating parameters.The research results could provide a reference for the performance improvement and application of plot drill.展开更多
In this paper,the gas and seed flow characters in the air-blowing seed metering device are investigated by using the coupled computational fluid dynamics and discrete element method(CFD-DEM)in three dimensions(3D).The...In this paper,the gas and seed flow characters in the air-blowing seed metering device are investigated by using the coupled computational fluid dynamics and discrete element method(CFD-DEM)in three dimensions(3D).The method of establishing boundary model based on the computer-aided design(CAD)drawing,has been used to build the boundary model of seed metering device.The 3D laser scanning technique and multi-element method are adopted to establish the particle model.Through a combined numerical and experimental effort,using 3D CFD-DEM software,which is based on the in-house codes,the mechanisms governing the gas and solid dynamic behaviors in the seed metering device have been studied.The gas velocity field and the effect of different rotational speeds and air pressures on the seeding performance and particle velocity have been studied,similar agreements between numerical and experimental results are gained.This reveals that the 3D CFD-DEM model established is able to predict the performance of the air-blowing seed metering device.It can be used to design and optimize the air-blowing seed metering device and other similar agriculture devices.展开更多
Single seed metering devices for Chinese flowering cabbage planting machines have suffered such deficiencies as low efficiency,poor accuracy,and instability.To overcome these limitations,a pneumatic double disc precis...Single seed metering devices for Chinese flowering cabbage planting machines have suffered such deficiencies as low efficiency,poor accuracy,and instability.To overcome these limitations,a pneumatic double disc precision seed metering device was designed.This innovative device can simultaneously plant four rows,considering the specific agricultural requirements and the geometric characteristics for Chinese flowering cabbage seeds.The precise parameters of the key component seed disc were derived through theoretical calculation.In addition,a detailed account was given for the working principle and workflow of the seed metering device.The discrete element method and EDEM software were employed to optimize the seed disc by exploring the effects of seed disc rotational speed and interleaving seed slots on seed viability.Orthogonal rotation experiments were conducted to evaluate the impact of seed disc rotational speed and negative pressure.While rates of qualified seeding,double seeding and missing seeding were adopted as test indicators.Testing results show that,at a seed disc rotational speed of 41.5 r/min and a negative pressure of 3.80 kPa,the average qualified seeding rate is 90.13%,the average missing seeding rate is 3.30%,and the average double seeding rate is 6.02%.These values satisfy the agricultural requirements for planting Chinese flowering cabbage.The findings can also provide valuable insights for the structural optimization and design of precision seed metering devices for Chinese flowering cabbage.展开更多
Seeding is an important part of improving corn yield.Currently,seed guide tubes are mostly used as transport devices.But the existing seed guide tubes cannot meet the requirements or achieve the goal of fixing the see...Seeding is an important part of improving corn yield.Currently,seed guide tubes are mostly used as transport devices.But the existing seed guide tubes cannot meet the requirements or achieve the goal of fixing the seed falling trajectory.A seed collision phenomenon occurs occasionally.So,in response to the problems that the seeds and seed guide tube collide or bounce under high speed operation,which results in a lower sowing qualification rate and poor spacing uniformity,a seed receiving and conveying system comprising a belt-type high-speed corn seed guiding device was designed and optimized,to meet the needs of high-speed precision sowing operations and improve the spacing uniformity.The factors affecting the seed conveying performance were obtained by analyzing the mechanical properties of the seeds at various movement stages.These factors were the number of seed cavities between adjacent seeds,the forward speed,the height from the ground,and the installation angle.Single factor simulation experiments were conducted by selecting the paddle spacing as the test factor and using the pass rate,reseeding rate,omission rate and coefficient of variation as the evaluation indexes to investigate the influence of the paddle spacing on the seed guide performance of the device and further determine the structural parameters of the paddle belt.Orthogonal rotation combination tests of three factors and five levels were also conducted through bench testing.Then the test outcomes were optimized.The results indicated that the best results were obtained when the number of seed cavity intervals between adjacent seeds was 5.16,the installation angle was 79.40°,and the height from the ground was 31.84 mm.At this time,the qualified rate was 98.49%,the repeated sowing rate was 0.48%,the missed sowing rate was 1.03%,and the coefficient of variation was 6.80%.Experiments were used to validate the optimization results,and all of the obtained index data satisfied the criteria for accurate and quick corn sowing.The study’s findings can serve as a theoretical foundation for a belt-type high-speed corn seed guiding device optimization test.展开更多
A secondary seeding precision double-seed peanut hole seeding seed metering device was designed to improve the performance of the peanut planting equipment and provide a solution for problems on the high seed charge t...A secondary seeding precision double-seed peanut hole seeding seed metering device was designed to improve the performance of the peanut planting equipment and provide a solution for problems on the high seed charge that can cause poor cavitation and uniformity easily.The main structure and operation parameters in terms of groove length,seed charge height,seed-bed belt speed,and rotation speed of the seed metering wheel were determined through theoretical analysis.Single-factor and orthogonal tests were carried out through the JPS-12 seed metering device test bench,and the peanut variety Jinonghua-3 was selected as the test object.The single hole double-seed rate,qualified rate,the variation coefficient of hole spacing,and hole rate were chosen for evaluating the working performance.The results of the single-factor test showed that the seed metering performance is mainly affected by the groove length,the speed of the seed-bed belt and the rotation speed of the seed metering wheel,and the influence of the cavitation rate is minimal.The optimal seeding height is determined to be 40 mm.The results of the orthogonal test showed that the groove length was 27.3 mm,the seed-bed belt speed was 1.51 km/h,and the rotation speed of the seed metering wheel was 14.11 r/min.What’s more,a regression model based on the orthogonal test results was established,the qualified rate of the number of holes obtained after optimizing the model was 98.84%,the variation coefficient of hole spacing was 9.74%,and the hole rate was 1.40%.Notably,the working performances of the device can meet the requirement of precision seeding.展开更多
In order to solve the problem of poor uniformity of wheat strip sowing,this paper designs a positive-negative pressure wheat wide-seedling-strip-seeding precision seed metering device,which adopts the roller structure...In order to solve the problem of poor uniformity of wheat strip sowing,this paper designs a positive-negative pressure wheat wide-seedling-strip-seeding precision seed metering device,which adopts the roller structure with the principle of combined positive-negative pressure.Through theoretical analysis and relevant data,the structure of the seed metering device and the structure of the positive-negative pressure air chamber were designed.The internal flow field conditions were simulated by Fluent software under different structural parameters.The design of the seed holes was completed by analyzing the pressure cloud diagram and the flow velocity vector diagram,and the optimal combination of parameters was obtained and the influence law of negative pressure on the flow field was obtained.The effect of rotational speed on the flow field was studied by EDEM-Fluent coupling technique.In this paper,a three-factor and three-level response surface test was conducted on a JPS-12 test bench with Liangxin-99 wheat as the research object.The experiment was conducted with the rotational speed of seed metering device,the negative pressure of seed suction and the seeding height as factors,and the qualified index,the reseeding index and the miss-seeding index as evaluation indicators.Through the test,the optimal structure and working parameters of the seed metering device were determined as follows:the diameter of the seed hole was 2 mm,and the number of seed holes per row was 28,negative pressure was−3.5 kPa,rotational speed of seed metering device was 19 r/min,and seeding height was 180 mm.Validation test was carried out on the optimized seed metering device:the qualified index was 80.62%,the reseeding index was 9.22%,and the miss-seeding index was 10.16%,which reached the parameter indicator in JB/T 10293-2013 Technical conditions of single seed(precision)seeder and met the agronomic requirements for wheat wide-seedling-strip-seeding.展开更多
In order to meet the agronomy demand for hybrid rice direct seeding,a novel precise pneumatic rice seed metering device was designed with groups of sucking holes plate,by which 3-4 seeds could be synchronously sucked ...In order to meet the agronomy demand for hybrid rice direct seeding,a novel precise pneumatic rice seed metering device was designed with groups of sucking holes plate,by which 3-4 seeds could be synchronously sucked and synchronously dropped into the paddy field.The plate was divided into five sections:seed sucking,seed clearing,seed carrying,seed dropping,and blank sections.The seeds were sucked in sucking section by the vacuum,carried and rotated to the dropping section with the plate,blown away in dropping section by the positive pressure air,and thrown into the dropping tube.The influences of the hole diameter,vacuum degree,and clear-up equipment on precision of metering device were discussed.Experiments were conducted to investigate the seeding precision and simulate the field emergence rates on the indoor seeding test-bed.The subjects were pregnant Indic hybrid Peizataifeng under two kinds of moisture content(23.43%and 26.07%).Other experiment conditions included the vacuum degree of 2.60 kPa,the rotation speed of seed sucking plate of 30 r/min,three sucking holes with a diameter of 1.6 mm,and the seed layer thickness of 25 mm.The seeding results showed that,in condition of no more than two seeds per hill,the emergence probabilities under the two moisture contents were 11.82%and 11.95%,respectively,and in condition of 3-4 seeds per hill,the results were 64.81%and 65.84%,respectively.With 2-5 seeds per hill,the results were 92.08%and 92.60%,respectively.If the emergence probability was 80%,under the two moisture contents,the no seed per hill probabilities were 1.33%and 0.80%respectively;the probabilities with 3-4 seeds per hill were 56.13%and 56.40%respectively;the probabilities with 5 or more seeds per hill were 10.67%and 10.13%respectively;the probabilities with 2-5 seeds per hill were 87.60%and 88.13%respectively.The results showed the simulated experiment was an efficient and economic method to assess the capability of pneumatic rice seed drilling metering device,and the precise pneumatic rice seed drilling metering device had a good prospect in practical application.展开更多
A ripple surface type pickup finger was designed to improve the performance of pickup finger precision maize seed metering device and to provide a solution for precision maize planter.The main structure and working pr...A ripple surface type pickup finger was designed to improve the performance of pickup finger precision maize seed metering device and to provide a solution for precision maize planter.The main structure and working principle of seed metering device were detailed in this paper.The dimension size distributions of maize seeds in different types were studied,the gestures of seeds clamped by pickup finger were analyzed,and the clamping dynamical model of pickup finger was established by theoretical analysis.To optimize the structural parameters of ripple surface type pickup finger,the discrete element method(DEM)model of pickup finger precision maize seed metering device was established by the discrete element software EDEM.The numerical simulations of orthogonal seeding performance experiments were conducted to analyze the influences of these factors on the quality of seeding.The rotational speed,wavelength of ripple surface and amplitude of ripple surface were selected as the experimental factors.The average seeding qualified index and the average seeding coefficient of variation on four different types of maize seeds were chosen for evaluating the seeding performance.The results showed that,the average seeding qualified index was 93.35%and the average seeding coefficient of variation was 11.23%under conditions of the 25 r/min rotational speed,8 mm wavelength of ripple surface and 2 mm amplitude of ripple surface.Under the same condition,the bench test was done which showed that the results of test and simulation were consistent.The maximum error of qualified index was 1.95%and the qualified index of improved seed metering device exceeded the original one by 12.34%.The working performance can meet the requirements of precision maize seeding.展开更多
An air-suction potato seed metering device was designed to improve the performance of the large-size seed crops planting equipment and provide a solution for problems on the mechanical potato seeder,such as high multi...An air-suction potato seed metering device was designed to improve the performance of the large-size seed crops planting equipment and provide a solution for problems on the mechanical potato seeder,such as high multiple-seeding index,high missing-seeding index,low qualified index,and limited versatility.The main structure and operation parameters in terms of rotating speed of the device,seeds height and pickup vacuum pressure were determined by theoretical analysis.Two orthogonal tests,conventional tuber(the triaxial average diameter is about 38-57 mm)test and mini-tuber(the triaxial average diameter is about 12-36 mm)test,were conducted to analyze the influences of these factors on the quality of seeding.The multiple-seeding index,missing-seeding index and qualified index were chosen for evaluating the working performance.The results of conventional tuber test showed that,the multiple-seeding index was 1.1%,the missing-seeding index was 0.8%and the qualified index was 98.1%under conditions of the 30 r/min rotating speed,25 cm seeds height and 10 kPa pickup vacuum pressure.The results of mini-tuber test showed that the multiple-seeding index was 0.5%,the missing-seeding index was 0.6%and the qualified index was 98.9%under conditions of 35 r/min rotating speed,17 cm seeds height and 3.5 kPa pickup vacuum.The working performances of the device can meet the requirements of precision seeding.展开更多
Since the low seed filling speed of mechanical seed metering devices reduces the low qualified rate of seed spacing during high-speed practices,it is significant to design agitated seed metering devices with horizonta...Since the low seed filling speed of mechanical seed metering devices reduces the low qualified rate of seed spacing during high-speed practices,it is significant to design agitated seed metering devices with horizontal seed filling that are suitable for high-speed practices.The combination of horizontal seed filling and agitated seed filling can accelerate the seed filling of mechanical seed metering devices,and improve the qualified rate of seed spacing during high-speed practices.In this study,theoretical analysis,discrete element method-based simulation and indoor bench test verification were conducted to investigate how key parameters of the agitated seed metering device with horizontal seed filling(angles,installation position and number of agitating plates,diameters of convex spoons)would affect the characteristics of soybean seed movement,seed number and seeding performance(qualified index,multiple index,missing seeding index)under different working speeds.Computer-based simulation,test design and regression analysis were combined to analyze the population moving rules and optimize the design parameters of seed metering devices.Based on the test scheme as designed,simulations were conducted on Fluent EDEM,and the optimal angle of the agitating plates was determined by analyzing the population migrating rules.Regression equations were established through the regression of test results,and used to find out the optimal design parameters(diameter of convex spoon,positions and number of agitating plates)of seed metering devices.Then the optimal parameter combination among different working conditions was determined that the angle,position and number of agitating plates were 30°,24.4 mm,and 13,respectively,and the diameter of convex spoon was 11.0 mm.With the optimal parameter combination and at the seeding speed of 12 km/h,the qualified index,multiple index and missing seeding index were 93.1%,2.1%and 4.8%,respectively.Under high-speed practices,the new seed metering device was not significantly different from the pneumatic seed metering device,but significantly outperformed the mechanical seed metering device.展开更多
In order to solve the problem of interaction between multiple evaluation indexes of seed metering performance under multiple factors of centralized seed feeding device,a multi-objective optimization of structure based...In order to solve the problem of interaction between multiple evaluation indexes of seed metering performance under multiple factors of centralized seed feeding device,a multi-objective optimization of structure based on particle swarm optimization(PSO)algorithm was proposed in this paper.The wheat centralized seed feeding device was taken as the research object,and the experimental factors were cone angle of type hole,working speed and seed filling gap.The working process of wheat centralized seed feeding device was simulated by discrete element method(DEM).The average seed number of type hole,the variation coefficient of the average seed number of type hole,and the maximum tangential force between seed and seed feeding mechanism were selected as the evaluation indexes.Through the variance analysis of the evaluation indexes by the experimental factors,the optimization objective function was constructed.Using PSO algorithm,the multi-objective optimization was carried out for the wheat centralized seed feeding device.The optimization results show that the best structural combination parameters of the wheat centralized seed feeding device are the hole cone angle of 31.6°and the seed filling gap of 4.6 mm.The validity of the method was verified by simulation and field test.The results show that the PSO algorithm multi-objective optimization method proposed in this paper can provide a reference for the structural improvement and optimal design of the centralized seed feeding device.展开更多
To address the clogging of the rice seed metering device after a long period of operation without affecting the precision of normal seeding,an active seed throwing and cleaning unit was designed based on the fact that...To address the clogging of the rice seed metering device after a long period of operation without affecting the precision of normal seeding,an active seed throwing and cleaning unit was designed based on the fact that magnets of the same pole were mutually exclusive.The working principle of the two devices was analysed theoretically,and a mechanical model was created according to the relationship between the repulsion forces of magnets and the spring forces of springs.The super hybrid rice Y-2 You 900 with 22.5%moisture content(wet basis)was used as the test object.The whole factor experiments were carried out under different negative pressures,rotational speeds of the suction plates,and lengths of probes.The results indicated that under any test conditions,the active seed throwing and cleaning unit worked normally.The results of high-speed photography showed that the rate of seed cleaning was 100%.The results also showed that the optimal negative pressure was 0.8 kPa.The probability of 1-3 seeds per hill for the seed metering device was approximately 95%under the optimal negative pressure.The optimal length of the probe was found to be 2 mm.The average qualified rate of hill space was 96.04%under the optimal length of probe,the longer the length of the probe,the lower the qualified rate of hill space.It also showed that an active seed throwing and cleaning unit could effectively avoid the hole clogging caused by the long-term operation and had no influence on the normal operation of the pneumatic rice seed metering device.The active seed throwing and cleaning unit improved the stability of the seed metering device,and the research provided a reference for the optimal design of seed throwing and cleaning structures of the pneumatic rice seed metering device.展开更多
Uniformseed distribution within the row is the prime objective of precision planters for better crop growth and yield.Inclined plate planters are generally used for sowing bold seeds likemaize,groundnut,chickpea,and t...Uniformseed distribution within the row is the prime objective of precision planters for better crop growth and yield.Inclined plate planters are generally used for sowing bold seeds likemaize,groundnut,chickpea,and their operating parameters like the forward speed of operation,the seedmetering plate inclination,and the seed level in the hopper affect the cell fill and subsequently the uniformseed distribution.Therefore,to achieve precise seed distribution,these parameters need to be optimized.In the present study,out of the different optimization techniques,a new intelligent optimization technique based on the integrated ANN-PSO approach has been used to achieve the set goal.A 3–5-1 artificial neural network(ANN)model was developed for predicting the cell fill of inclined plate seedmetering device,and the particle swarmoptimization(PSO)algorithmwas applied to obtain the optimum values of the operating parameters corresponding to 100%cell fill.The most appropriate optimal values of the forward speed of operation,the seed metering plate inclination,and the seed level in the hopper for achieving 100%cell fill were found to be 3 km/h,50-degree,and 75%of total height,respectively.The proposed integrated ANN-PSO approach was capable of predicting the optimal values of operating parameters with amaximumdeviation of 2%compared to the experimental results,thus confirmed the reliability of the proposed optimization technique.展开更多
基金financially supported by National Key Research and Development Project(Grant No.2017YFD0700805)Special Fund for Basic Scientific Research Business Expenses of Chinese Academy of Tropical Agricultural Sciences(Grant No.1630132022001)+2 种基金Hainan Natural Science Foundation Project(Grant No.520QN331)Zhanjiang Science and Technology Plan Project(Grant No.2021A05011 and 2021A05189)Special Topic on the Construction of Key Laboratory of Zhanjiang Science and Technology Planning Project(Grant No.2020A05004).
文摘Mechanized sugarcane seeding is one of the effective technical measures for improving seeding uniformity and operation efficiency.However,the imperfection of supporting equipment limits the promotion and application of this technology.As there are some problems in domestic sugarcane planting machines currently,such as large auxiliary labor,high labor intensity,low seeding uniformity,and large amount of seeds,a disc-type single-bud sugarcane seed metering device was innovatively designed on the basis of the analysis of physical properties of single-bud sugarcane seeds and the combination with agronomic requirements for field planting in this paper.Solidworks was used to simulate and analyze the mechanism,check the theoretical parameters,and process the test prototype.Through single-factor experiments,the effective factors affecting seeding uniformity were determined.A multi-factor orthogonal rotation test was designed,data were collected and then SPSS was used to get the optimal parameters for the seeding uniformity:the advancement speed of machine is 0.22 m/s,the number of disc seeding grooves is 10,the rotating disc speed is 0.18 r/s,and the seeding uniformity is 86.2%;the seeding uniformity was verified by field trial,and the results showed that the average seeding uniformity of the field verification was 83%,with the error 3.2% relative to the optimization result.The relative error is within 10%,indicating that the optimization result is reliable and meets the requirements of seeding uniformity,thus providing theoretical basis for the research and development of the disc-type single-bud seeding device.
基金This study was supported by the Program for China Agriculture Research System(Grant No.CARS-03)Chinese Universities Scientific Fund(Grant No.2020TC116)+1 种基金Research Innovation Fund for Graduate Students of China Agricultural University(CAU)(Grant No.2020XYZC06A)The authors thank all the members working at the Conservation Tillage Research Centre and for proving their inputs to this paper.
文摘Plot drill has a significant impact on field breeding by replacing manual seeding.However,the seeding performance of plot drill needs to be further improved as the mechanical transmission method cannot work under the optimal combination of operating parameters.In this study,a cone compartment tray of sowing device was evaluated under the laboratory conditions,using a self-designed seeding control system to adjust the operating parameters.Among them,a plot seeding control system was involved that could set operating parameters through an Android terminal,which effectively reduced the difficulty of parameters adjustment.The method of central composite experiment design was employed to conduct experiments and explore the effects of experiment factors such as lifting height of storage tube(LHST),rotation speed of cone compartment tray(RSCCT),and rotation speed seed distributor(RSSD)on the seeding uniformity coefficient of variation among rows(SUCVR)and the rate of damaged seeds(RDS).For SUCVR of wheat,the results showed that the importance order of main factors from high to low was RSSD,RSCCT and LHST.And for SUCVR of buckwheat,RSCCT had the largest influence,followed by RSSD,and LHST had the smallest influence.For RDS of wheat and buckwheat,only RSSD had a very significant effect among the main factors.The experiments data of wheat indicated that when operated at 27.2 mm for LHST,4.5 r/min for RSCCT and 1169 r/min for RSSD,the sowing performance of wheat was optimal,with SUCVR and RDS values of 5.02%and 0.117%,respectively.The buckwheat seeding performance was found to be optimal when the LHST,RSCCT and RSSD were 26.5 mm,3.9 r/min and 711 r/min,and SUCVR and RDS were 4.74%and 0.113%.The seeding control system realized the electromechanical control of the seeding equipment,was convenient for parameter setting and stepless adjustment,and could be operated under an optimized combination of operating parameters.The research results could provide a reference for the performance improvement and application of plot drill.
基金The authors would like to express appreciation for the support of Australia Research Council(IH140100035)Nature Science Foundation of China(51675218)+1 种基金Doctor Starting Foundation of Jiangxi University of Science and Technology(JXXJBS17078)Science and Technology Project of the Education Department of Jiangxi Province(GJJ180426).
文摘In this paper,the gas and seed flow characters in the air-blowing seed metering device are investigated by using the coupled computational fluid dynamics and discrete element method(CFD-DEM)in three dimensions(3D).The method of establishing boundary model based on the computer-aided design(CAD)drawing,has been used to build the boundary model of seed metering device.The 3D laser scanning technique and multi-element method are adopted to establish the particle model.Through a combined numerical and experimental effort,using 3D CFD-DEM software,which is based on the in-house codes,the mechanisms governing the gas and solid dynamic behaviors in the seed metering device have been studied.The gas velocity field and the effect of different rotational speeds and air pressures on the seeding performance and particle velocity have been studied,similar agreements between numerical and experimental results are gained.This reveals that the 3D CFD-DEM model established is able to predict the performance of the air-blowing seed metering device.It can be used to design and optimize the air-blowing seed metering device and other similar agriculture devices.
基金supported by Collaborative Innovation Center for Shandong’s Main Crop Production Equipment and Mechanization,Qingdao Shandong 266109,China。
文摘Single seed metering devices for Chinese flowering cabbage planting machines have suffered such deficiencies as low efficiency,poor accuracy,and instability.To overcome these limitations,a pneumatic double disc precision seed metering device was designed.This innovative device can simultaneously plant four rows,considering the specific agricultural requirements and the geometric characteristics for Chinese flowering cabbage seeds.The precise parameters of the key component seed disc were derived through theoretical calculation.In addition,a detailed account was given for the working principle and workflow of the seed metering device.The discrete element method and EDEM software were employed to optimize the seed disc by exploring the effects of seed disc rotational speed and interleaving seed slots on seed viability.Orthogonal rotation experiments were conducted to evaluate the impact of seed disc rotational speed and negative pressure.While rates of qualified seeding,double seeding and missing seeding were adopted as test indicators.Testing results show that,at a seed disc rotational speed of 41.5 r/min and a negative pressure of 3.80 kPa,the average qualified seeding rate is 90.13%,the average missing seeding rate is 3.30%,and the average double seeding rate is 6.02%.These values satisfy the agricultural requirements for planting Chinese flowering cabbage.The findings can also provide valuable insights for the structural optimization and design of precision seed metering devices for Chinese flowering cabbage.
基金financially supported by the National Natural Science Foundation(Grant No.52275246)the Key Research and Development Plan Project of Heilongjiang Province(Grant No.2022ZX05B02).
文摘Seeding is an important part of improving corn yield.Currently,seed guide tubes are mostly used as transport devices.But the existing seed guide tubes cannot meet the requirements or achieve the goal of fixing the seed falling trajectory.A seed collision phenomenon occurs occasionally.So,in response to the problems that the seeds and seed guide tube collide or bounce under high speed operation,which results in a lower sowing qualification rate and poor spacing uniformity,a seed receiving and conveying system comprising a belt-type high-speed corn seed guiding device was designed and optimized,to meet the needs of high-speed precision sowing operations and improve the spacing uniformity.The factors affecting the seed conveying performance were obtained by analyzing the mechanical properties of the seeds at various movement stages.These factors were the number of seed cavities between adjacent seeds,the forward speed,the height from the ground,and the installation angle.Single factor simulation experiments were conducted by selecting the paddle spacing as the test factor and using the pass rate,reseeding rate,omission rate and coefficient of variation as the evaluation indexes to investigate the influence of the paddle spacing on the seed guide performance of the device and further determine the structural parameters of the paddle belt.Orthogonal rotation combination tests of three factors and five levels were also conducted through bench testing.Then the test outcomes were optimized.The results indicated that the best results were obtained when the number of seed cavity intervals between adjacent seeds was 5.16,the installation angle was 79.40°,and the height from the ground was 31.84 mm.At this time,the qualified rate was 98.49%,the repeated sowing rate was 0.48%,the missed sowing rate was 1.03%,and the coefficient of variation was 6.80%.Experiments were used to validate the optimization results,and all of the obtained index data satisfied the criteria for accurate and quick corn sowing.The study’s findings can serve as a theoretical foundation for a belt-type high-speed corn seed guiding device optimization test.
基金This work was financially supported by the Modern Agricultural Industrial Technology System Oil Industry Innovation Team Building Project of Hebei Province(Grant No.HBCT2018090206)the Hebei Province Youth Top Talent Funding Project.
文摘A secondary seeding precision double-seed peanut hole seeding seed metering device was designed to improve the performance of the peanut planting equipment and provide a solution for problems on the high seed charge that can cause poor cavitation and uniformity easily.The main structure and operation parameters in terms of groove length,seed charge height,seed-bed belt speed,and rotation speed of the seed metering wheel were determined through theoretical analysis.Single-factor and orthogonal tests were carried out through the JPS-12 seed metering device test bench,and the peanut variety Jinonghua-3 was selected as the test object.The single hole double-seed rate,qualified rate,the variation coefficient of hole spacing,and hole rate were chosen for evaluating the working performance.The results of the single-factor test showed that the seed metering performance is mainly affected by the groove length,the speed of the seed-bed belt and the rotation speed of the seed metering wheel,and the influence of the cavitation rate is minimal.The optimal seeding height is determined to be 40 mm.The results of the orthogonal test showed that the groove length was 27.3 mm,the seed-bed belt speed was 1.51 km/h,and the rotation speed of the seed metering wheel was 14.11 r/min.What’s more,a regression model based on the orthogonal test results was established,the qualified rate of the number of holes obtained after optimizing the model was 98.84%,the variation coefficient of hole spacing was 9.74%,and the hole rate was 1.40%.Notably,the working performances of the device can meet the requirement of precision seeding.
基金supported by State Key Laboratory of North China Crop Improvement and RegulationKey R&D Projects in Hebei Province(Grant No.21327215D)Funding Projects for the Returned Overseas Chinese Scholars in 2020,China(Grant No.C20200337).
文摘In order to solve the problem of poor uniformity of wheat strip sowing,this paper designs a positive-negative pressure wheat wide-seedling-strip-seeding precision seed metering device,which adopts the roller structure with the principle of combined positive-negative pressure.Through theoretical analysis and relevant data,the structure of the seed metering device and the structure of the positive-negative pressure air chamber were designed.The internal flow field conditions were simulated by Fluent software under different structural parameters.The design of the seed holes was completed by analyzing the pressure cloud diagram and the flow velocity vector diagram,and the optimal combination of parameters was obtained and the influence law of negative pressure on the flow field was obtained.The effect of rotational speed on the flow field was studied by EDEM-Fluent coupling technique.In this paper,a three-factor and three-level response surface test was conducted on a JPS-12 test bench with Liangxin-99 wheat as the research object.The experiment was conducted with the rotational speed of seed metering device,the negative pressure of seed suction and the seeding height as factors,and the qualified index,the reseeding index and the miss-seeding index as evaluation indicators.Through the test,the optimal structure and working parameters of the seed metering device were determined as follows:the diameter of the seed hole was 2 mm,and the number of seed holes per row was 28,negative pressure was−3.5 kPa,rotational speed of seed metering device was 19 r/min,and seeding height was 180 mm.Validation test was carried out on the optimized seed metering device:the qualified index was 80.62%,the reseeding index was 9.22%,and the miss-seeding index was 10.16%,which reached the parameter indicator in JB/T 10293-2013 Technical conditions of single seed(precision)seeder and met the agronomic requirements for wheat wide-seedling-strip-seeding.
基金Financial support for this study was provided by National Natural Science Foundation of China(Grant No.51105147)Chinese Agriculture Commonweal Projects(Grant No.201203059)+1 种基金National High Technology Research and Development Program 863(Grant No.2014AA10A605-8)Fundamental Research Funds for the Central Universities(Grant No.2013PY123,2014PY043).
文摘In order to meet the agronomy demand for hybrid rice direct seeding,a novel precise pneumatic rice seed metering device was designed with groups of sucking holes plate,by which 3-4 seeds could be synchronously sucked and synchronously dropped into the paddy field.The plate was divided into five sections:seed sucking,seed clearing,seed carrying,seed dropping,and blank sections.The seeds were sucked in sucking section by the vacuum,carried and rotated to the dropping section with the plate,blown away in dropping section by the positive pressure air,and thrown into the dropping tube.The influences of the hole diameter,vacuum degree,and clear-up equipment on precision of metering device were discussed.Experiments were conducted to investigate the seeding precision and simulate the field emergence rates on the indoor seeding test-bed.The subjects were pregnant Indic hybrid Peizataifeng under two kinds of moisture content(23.43%and 26.07%).Other experiment conditions included the vacuum degree of 2.60 kPa,the rotation speed of seed sucking plate of 30 r/min,three sucking holes with a diameter of 1.6 mm,and the seed layer thickness of 25 mm.The seeding results showed that,in condition of no more than two seeds per hill,the emergence probabilities under the two moisture contents were 11.82%and 11.95%,respectively,and in condition of 3-4 seeds per hill,the results were 64.81%and 65.84%,respectively.With 2-5 seeds per hill,the results were 92.08%and 92.60%,respectively.If the emergence probability was 80%,under the two moisture contents,the no seed per hill probabilities were 1.33%and 0.80%respectively;the probabilities with 3-4 seeds per hill were 56.13%and 56.40%respectively;the probabilities with 5 or more seeds per hill were 10.67%and 10.13%respectively;the probabilities with 2-5 seeds per hill were 87.60%and 88.13%respectively.The results showed the simulated experiment was an efficient and economic method to assess the capability of pneumatic rice seed drilling metering device,and the precise pneumatic rice seed drilling metering device had a good prospect in practical application.
基金the National Science and Technology Support Plan Project(2014BAD06B04).
文摘A ripple surface type pickup finger was designed to improve the performance of pickup finger precision maize seed metering device and to provide a solution for precision maize planter.The main structure and working principle of seed metering device were detailed in this paper.The dimension size distributions of maize seeds in different types were studied,the gestures of seeds clamped by pickup finger were analyzed,and the clamping dynamical model of pickup finger was established by theoretical analysis.To optimize the structural parameters of ripple surface type pickup finger,the discrete element method(DEM)model of pickup finger precision maize seed metering device was established by the discrete element software EDEM.The numerical simulations of orthogonal seeding performance experiments were conducted to analyze the influences of these factors on the quality of seeding.The rotational speed,wavelength of ripple surface and amplitude of ripple surface were selected as the experimental factors.The average seeding qualified index and the average seeding coefficient of variation on four different types of maize seeds were chosen for evaluating the seeding performance.The results showed that,the average seeding qualified index was 93.35%and the average seeding coefficient of variation was 11.23%under conditions of the 25 r/min rotational speed,8 mm wavelength of ripple surface and 2 mm amplitude of ripple surface.Under the same condition,the bench test was done which showed that the results of test and simulation were consistent.The maximum error of qualified index was 1.95%and the qualified index of improved seed metering device exceeded the original one by 12.34%.The working performance can meet the requirements of precision maize seeding.
基金the China Agriculture Research System Special Foundation CARS-10-P22National Science and Technology Support Project 2014BAD06B03+1 种基金Yunnan Province Winter Pollution-free Yield Technology System Construction and Application Projects Funded 2014YNC001Heilongjiang Province Key Science and Technology Project GA15B401.
文摘An air-suction potato seed metering device was designed to improve the performance of the large-size seed crops planting equipment and provide a solution for problems on the mechanical potato seeder,such as high multiple-seeding index,high missing-seeding index,low qualified index,and limited versatility.The main structure and operation parameters in terms of rotating speed of the device,seeds height and pickup vacuum pressure were determined by theoretical analysis.Two orthogonal tests,conventional tuber(the triaxial average diameter is about 38-57 mm)test and mini-tuber(the triaxial average diameter is about 12-36 mm)test,were conducted to analyze the influences of these factors on the quality of seeding.The multiple-seeding index,missing-seeding index and qualified index were chosen for evaluating the working performance.The results of conventional tuber test showed that,the multiple-seeding index was 1.1%,the missing-seeding index was 0.8%and the qualified index was 98.1%under conditions of the 30 r/min rotating speed,25 cm seeds height and 10 kPa pickup vacuum pressure.The results of mini-tuber test showed that the multiple-seeding index was 0.5%,the missing-seeding index was 0.6%and the qualified index was 98.9%under conditions of 35 r/min rotating speed,17 cm seeds height and 3.5 kPa pickup vacuum.The working performances of the device can meet the requirements of precision seeding.
基金supported by the 13th Five-Year Plan for National Science and Technology(Grant No.2016YFD0700302)National Natural Science Foundation of China(51705194)(JJKH20170811KJ).
文摘Since the low seed filling speed of mechanical seed metering devices reduces the low qualified rate of seed spacing during high-speed practices,it is significant to design agitated seed metering devices with horizontal seed filling that are suitable for high-speed practices.The combination of horizontal seed filling and agitated seed filling can accelerate the seed filling of mechanical seed metering devices,and improve the qualified rate of seed spacing during high-speed practices.In this study,theoretical analysis,discrete element method-based simulation and indoor bench test verification were conducted to investigate how key parameters of the agitated seed metering device with horizontal seed filling(angles,installation position and number of agitating plates,diameters of convex spoons)would affect the characteristics of soybean seed movement,seed number and seeding performance(qualified index,multiple index,missing seeding index)under different working speeds.Computer-based simulation,test design and regression analysis were combined to analyze the population moving rules and optimize the design parameters of seed metering devices.Based on the test scheme as designed,simulations were conducted on Fluent EDEM,and the optimal angle of the agitating plates was determined by analyzing the population migrating rules.Regression equations were established through the regression of test results,and used to find out the optimal design parameters(diameter of convex spoon,positions and number of agitating plates)of seed metering devices.Then the optimal parameter combination among different working conditions was determined that the angle,position and number of agitating plates were 30°,24.4 mm,and 13,respectively,and the diameter of convex spoon was 11.0 mm.With the optimal parameter combination and at the seeding speed of 12 km/h,the qualified index,multiple index and missing seeding index were 93.1%,2.1%and 4.8%,respectively.Under high-speed practices,the new seed metering device was not significantly different from the pneumatic seed metering device,but significantly outperformed the mechanical seed metering device.
基金The authors acknowledge that this work was financially supported by Collaborative Innovation Project of Anhui Colleges and Universities(GXXT-2019-036)Nature Science Fund Project of Anhui province(2008085QE217)Natural Science Fund Project of Anhui Agricultural University(2019zd09).
文摘In order to solve the problem of interaction between multiple evaluation indexes of seed metering performance under multiple factors of centralized seed feeding device,a multi-objective optimization of structure based on particle swarm optimization(PSO)algorithm was proposed in this paper.The wheat centralized seed feeding device was taken as the research object,and the experimental factors were cone angle of type hole,working speed and seed filling gap.The working process of wheat centralized seed feeding device was simulated by discrete element method(DEM).The average seed number of type hole,the variation coefficient of the average seed number of type hole,and the maximum tangential force between seed and seed feeding mechanism were selected as the evaluation indexes.Through the variance analysis of the evaluation indexes by the experimental factors,the optimization objective function was constructed.Using PSO algorithm,the multi-objective optimization was carried out for the wheat centralized seed feeding device.The optimization results show that the best structural combination parameters of the wheat centralized seed feeding device are the hole cone angle of 31.6°and the seed filling gap of 4.6 mm.The validity of the method was verified by simulation and field test.The results show that the PSO algorithm multi-objective optimization method proposed in this paper can provide a reference for the structural improvement and optimal design of the centralized seed feeding device.
基金funding from National key research program(Project No.2017YFD07000700,2017YFD07000704)Commonweal Project(Project No.201203059)+1 种基金National Natural Science Foundation of China(Project No.51105147)Foundation of Guangdong Province of China(Project No.S2011010001948).
文摘To address the clogging of the rice seed metering device after a long period of operation without affecting the precision of normal seeding,an active seed throwing and cleaning unit was designed based on the fact that magnets of the same pole were mutually exclusive.The working principle of the two devices was analysed theoretically,and a mechanical model was created according to the relationship between the repulsion forces of magnets and the spring forces of springs.The super hybrid rice Y-2 You 900 with 22.5%moisture content(wet basis)was used as the test object.The whole factor experiments were carried out under different negative pressures,rotational speeds of the suction plates,and lengths of probes.The results indicated that under any test conditions,the active seed throwing and cleaning unit worked normally.The results of high-speed photography showed that the rate of seed cleaning was 100%.The results also showed that the optimal negative pressure was 0.8 kPa.The probability of 1-3 seeds per hill for the seed metering device was approximately 95%under the optimal negative pressure.The optimal length of the probe was found to be 2 mm.The average qualified rate of hill space was 96.04%under the optimal length of probe,the longer the length of the probe,the lower the qualified rate of hill space.It also showed that an active seed throwing and cleaning unit could effectively avoid the hole clogging caused by the long-term operation and had no influence on the normal operation of the pneumatic rice seed metering device.The active seed throwing and cleaning unit improved the stability of the seed metering device,and the research provided a reference for the optimal design of seed throwing and cleaning structures of the pneumatic rice seed metering device.
文摘Uniformseed distribution within the row is the prime objective of precision planters for better crop growth and yield.Inclined plate planters are generally used for sowing bold seeds likemaize,groundnut,chickpea,and their operating parameters like the forward speed of operation,the seedmetering plate inclination,and the seed level in the hopper affect the cell fill and subsequently the uniformseed distribution.Therefore,to achieve precise seed distribution,these parameters need to be optimized.In the present study,out of the different optimization techniques,a new intelligent optimization technique based on the integrated ANN-PSO approach has been used to achieve the set goal.A 3–5-1 artificial neural network(ANN)model was developed for predicting the cell fill of inclined plate seedmetering device,and the particle swarmoptimization(PSO)algorithmwas applied to obtain the optimum values of the operating parameters corresponding to 100%cell fill.The most appropriate optimal values of the forward speed of operation,the seed metering plate inclination,and the seed level in the hopper for achieving 100%cell fill were found to be 3 km/h,50-degree,and 75%of total height,respectively.The proposed integrated ANN-PSO approach was capable of predicting the optimal values of operating parameters with amaximumdeviation of 2%compared to the experimental results,thus confirmed the reliability of the proposed optimization technique.
