Vacuum and Air Flow for 2QXP-1 Vacuum Precision Seed Metering

Vacuum precision seed metering is the key part of vacuum seed planter. Planting performance of planter is affected by vacuum and air flow which are important parameters for choosing fan. Effects of qualification percent and miss percent on air chamber vacuum 3, 4, 5 and 6 kPa were studied at different operating speeds. The results showed that operating performance of the seed metering was excellent when air chamber vacuum was 5 and 6 kPa, which air flow was 7.4-8.0 m3·s-1 and 8.0-8.8 m3·s-1 , respectively.

Design and experiment of the pneumatic double disc precision seed metering device for Chinese flowering cabbage

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.

Development and evaluation of a low-cost precision seeding control system for a corn drill

Precision seeding requires that the corn drill drop seeds into the soil by a specific in-row spacing while its travelling speed fluctuates due to unevenness of the field ground.This paper presents a low-cost precision seeding control system for a conventional corn drill with mechanical metering devices of finger-pickup type.A median filtering method was implemented in the control system to process measurements from a rotary encoder in order to acquire stable values of the corn drill travelling speed.The metering unit was driven by an electric motor controlled by the metering ECU according to the actual travelling speed and the desired in-row spacing in real-time.A user interface was programmed to communicate with ECUs for configuring parameters and displaying operating information during working.The newly-developed precision seeding control system was first calibrated in terms of speed measurement and control for two ECUs.Experiments were conducted on a seeding test platform in the laboratory for evaluating its accuracy in dropping seeds by giving different in-row spacing under different travelling speeds of the conveyor sticky belt.Results showed that the average spacing error was less than 2 cm and the maximum RMS error was 0.78 cm for all spacing values including 25 cm,30 cm and 35 cm under the travelling speed of 1.0-8.0 km/h.These indicated that the low-cost precision seeding control system worked in a both accurate and stable way.

Design and experimental study of seed precise delivery mechanism for high-speed maize planter

Aiming at improving the seed spacing uniformity of maize planter at high forward speed,a seed precise delivery mechanism driven by electric motor has been developed and evaluated in laboratory.The mechanism was designed to deliver single seed from seed meter to furrow.Seed’s movement from the seed release point in a seed meter to the seed delivery cavity in the belt was analyzed,the mathematical model of seed movement in the seed precise delivery mechanism was established based on seed delivery time analysis.A mechanical prototype was designed and associated control system was developed.The performance contrast experiment was conducted between a traditional seed tube and newly developed seed precise delivery mechanism,and test results indicated that the qualities of feed index of the seed precise delivery mechanism were higher than those of the traditional seed tube delivery mechanism,and the coefficients of variation of the seed precise delivery mechanism were lower than those of the traditional seed tube delivery mechanism when the forward speed of planter was set at 10 km/h,12 km/h and 14 km/h,respectively.It indicated the seed precise delivery mechanism significantly improved seed spacing uniformity of maize planter compared with the traditional seed tube delivery mechanism.

Optimization method for accurate positioning seeding based on sowing decision

Variable seeding by sowing decision can improve the utilization rate of resources.In order to achieve more accurate position control and sowing rate control,precision sowing decision control system was developed,and the integral separation Proportional Integral Derivative(PID)control algorithm of metering disc speed and grid based dead reckoning method were proposed.In order to test the performance of the system,the experiment of the influence of integral switching on step response and the experiment of seeding response based on simulated sowing decision were carried out.The results showed that average lag distance based on dead reckoning was 72.2 cm less than that of non-dead reckoning;system response distance of integral separation PID control algorithm was 43.1 cm shorter than that of ordinary PID control algorithm.The field experiment showed that the error of the monitoring sowing rate relative to the actual sowing rate was 3.5%,the average transition distance within the speed range of 3-9 km/h was 139.5 cm,and the standard deviation was 12.8 cm.The developed seeding control system improves the accuracy of seeding based on sowing decision,and provides a technical reference for low-cost sowing decision based control system in China.

Effect and economic benefit of precision seeding and laser land leveling for winter wheat in the middle of China

Rapid socio-economic changes in China,such as land conversion and urbanization,are creating new scopes for the application of precision agriculture(PA).An experiment to assess the economic benefits of two precision agriculture methods was applied for one year–precision seeding and precision seeding with land leveling.Whilst the results for this were positive,of itself it did not provide evidence of longer terms gains.The costs of land leveling are accrued in a single year but the benefits could carry over into subsequent years.Thus,in this case if the PA method provides carry over benefits to future years,the economic assessment would incorrectly assign all the costs to a single year of benefits i.e.the benefit-cost ratio would be underestimated.To gauge whether there was carry over benefits in future years we looked at NDVI and GUI as proxies for future year benefits.For the single year experiment,our results showed that:(1)Winter wheat yield was increased 23.2%through the integration of precision seeding and laser leveling technologies.(2)Both the single technology and the integrated technologies significant reduced the concentration of soil ammonium nitrogen at the depths of 60 cm;(3)The benefit/cost ratio's of the treatments exceeded that of the baseline by approximately 10%which translated to an increase of several hundred US$per hectare.The NDVI analysis showed that the effect of laser land leveling could last to the next two years.When considering the multi-year impact of land leveling,the benefit/cost ratio of PSLL will increase to 23.5%and 22.9%with and without laser land leveling subsidies.Making clear the eco-nomic benefits of using PA technologies will likely promote application of the technologies in the region.

Design of motor-driven precision seed-metering device with improved fuzzy PID controller for small peanut planters

Traditional passive ground wheel drive of peanut planters has displayed poor high-speed seeding performance and the slippage caused in case of sticky and wet soil.Given this,an integrated electric-driven precision seed metering device and controller were designed,which features the application of improved fuzzy PID algorithm.Based on a small peanut planter with one ridge width and duplicate rows,the servo motor drive is used to replace the traditional passive ground wheel.In addition,the satellite speed measurement is employed to complete the electric driving and controlling modification of the seed meter and precise seeding control.A working process mathematical model for the peanut metering device was established to conduct motor speed and field tests which aim at comparing performances between the conventional and the improved fuzzy PID controls.The motor speed trial shows that the average error of the actual speed of the improved fuzzy PID motor was±1 rad/min,and the coefficient of variation was less than 1%.Against the conventional one,it can better suppress overshoot and improve the response speed.The stable output speed can still be obtained even in case of step changes.Field tests show that when working at medium and low speeds,the qualified rate of plant spacing was greater than 98%,and the rate of missed sowing is<2%;while working at high speed,the qualified rate was greater than 94%,and the rate of missed sowing was less than 4%.The average plant spacing qualification rate of the seed device increased by 6.72%;compared with other electric-driven peanut seed meters,the plant spacing qualification rate increased by 4%during high-speed sowing.In summary,this study has provided an effective technical reference for high-speed precision planting of peanuts.

Optimized design of the pneumatic precision seed-metering device for carrots

The small size, light weight, irregular shape, and impurities that characterize seed groups increase clogging tendencies in the traditional seed-metering device thereby making it difficult to achieve high-speed precision seeding. A pneumatic seed-metering device with good seed-filling performance for carrot was designed in this study. By analyzing the movement state of seeds in the device under the theoretical condition, it was concluded that the minimum critical negative pressure value of air chamber was 0.32 kPa, which provided a theoretical basis for simulation and testing. ANSYS 17.0 Software was used to simulate the shape of the seeding plate hole. By comparing the pressure, air flow stability between the suction surface and the plug removal surface of the convection field, it was concluded that the conical hole was optimal. A bench verification test was conducted on the device. The average qualified rate, missing rate, and replaying rate were 81.48%, 4.07%, and 14.45%, respectively, which provided a strong reference for the design of carrot precision seed-metering device.

Design and key parameter optimization of an agitated soybean seed metering device with horizontal seed filling

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.

Design and experiment of an air-suction potato seed metering device

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.

Development and test of an electric precision seeder for small-size vegetable seeds

An electric seeder for small-size vegetable seeds was designed based on the power drive and the optical fiber detection technology.The seeder is driven by electric power during the sowing process.At the same time,using the fiber sensor technology to monitor the sowing condition,the seeder is more efficient with high seeding precision in terms of different seed sizes.In order to achieve the precision seeding for the 2-10 mm seeds,the driving motor is equipped in the rear crackle.The power drive reduces pollution and dyeing.Also the other components of the electric seeder were modularly designed.The seeder was designed with buckle,which could be quickly disassembled on the sowing machine to replace the sowing wheel.It can quickly adjust row spacing and sowing depth during sowing process to meet the requirements of agricultural planting.Field test was carried out for coriander,pakchoi,and radish on the accuracy and monitoring of the system,respectively.The results showed that during the field operation,the sowing precision of the sowing machine was 95%.When the seeder worked at the speeds of 3 km/h and 4 km/h,the relative error of the monitoring precision of the system was less than 6%.This system can meet the real-time monitoring requirements of the seed metering device and improve the quality of the sowing work.

Virtual simulation analysis and verification of seed-filling mechanism for dipper hill-drop precision direct rice seeder

In order to improve the seeder’seed-filling ability of the dipper hill-drop precision direct rice seeder,and to meet the mechanization requirement of high speed operation,the self-designed seeder was taken as the objective to explore its seed-filling mechanism and the movement status of rice seed in seed box from the perspective of mechanics.The force models of seed-filling process by dipper were established,and the influential regularity of its rotation speed to compressive resistance of seed population was analyzed as well.The image processing Module-Clipping of discrete element simulation software EDEM was used in the virtual simulation analysis for the process of the seed filling into the dipper,and the velocity relation curve and the force changing curve between rotation speed and seeds were obtained.According to the virtual experiment,the composite filling force of seeds,i.e.the qualified rate on filled rice seed amounts was the largest when rotation speed was at 40 r/min.The performance test bed of seeder was used to verify the simulation results,in which the qualified rate on scooped rice seed amounts was taken as the index,and six rotation speeds of seed-filling dipper were also selected for analysis of seed-filling ability of the device.The results are as follows:with the increase of working speed,the qualified rate on filled rice seed amounts fluctuated with a trend of cosine curve,the largest value was 94.16%occurred when the rotation speed of seed-filling dipper was at 40 r/min.The variation trend of simulation value was approximately consistent with that of verification value.The study can provide a reference for the research and development of mechanical seeder.

Design method and experiment of machinery for combined application of seed,fertilizer and herbicide

This study aimed to resolve the problems of full wheat straw returning to the field,which might readily cause stalk obstruction,poor sowing quality,and serious weeds at the seedling stage,affecting the growth of maize.Based on the idea of“simultaneous seeding and spraying,closed weeding”,this paper presented a design method for designing a corn seed-fertilizer-herbicide simultaneous operation machine,which focuses on the design of vertical active straw-removing anti-blocking device mechanism,design of nozzle key parameters,nozzle selection,seeding monomer analysis and spatial layout design of seed-fertilizer-herbicide mechanism.In addition,the interrelated formulas were deduced and machine design and field experiment were conducted.The experiment results showed that the average variation coefficient of spray uniformity of machines was 17.70%.The post-experiment weed amount was 8.9%,which was lower than that before sowing,8.5%lower than that before artificially closed weeding,and 14.3%lower than that in unenclosed weeding area.Moreover,the weeds were less in the working area of the machine,and the growth of corn was better.Compared with manual closed weeding,the average plant height uniformity and average stem diameter uniformity increased by 4.4%and 5.1%,respectively.Compared with unclosed weeding,the average plant height uniformity and average stem diameter uniformity increased by 18.3%and 10.8%,respectively.Overall,the rationality of the design method proposed in this paper was validated,and these can lay a foundation for the research and development of the same type of machine.

Design and experiment on the air-blowing and vibrating supply seed tray for precision seeders

Vacuum-vibration precision seeding technology is a crucial technology that affects the industrialization process of super rice plug seedlings.To solve the problems that the vibrating supply seed tray structure in a vacuum-vibration precision seeder caused the vibration of the whole machine and the decline of the seeding eligible rate under high frequency and large amplitude vibration,it is important to design a new supply seed tray structure.This research proposed a method to make the seeds“boiling”under the combined effect of air blowing and vibration,and designed the air-blowing and vibrating supply seed tray structure.FLUENT was used to analyze fluid motion inside the supply seed tray and optimize the structure parameters of the supply seed tray.The maximum airflow velocity was determined when the inlet air pressure was 22 kPa,the number of air inlets was 2,and the diameter of the holes at the bottom of the supply seed tray was 2 mm.Comparative experiments were carried out to prove the air-blowing and vibrating supply seed tray structure could reduce the vibration frequency by 1.5 Hz and decrease the amplitude by 0.25 mm.The mathematical regression models between the inlet air pressure,vibration frequency,amplitude,and seeding performance indexes were established by orthogonal experiments.Through the optimization operation and bench tests,it was determined that when the inlet air pressure was 19.49 kPa,the vibration frequency was 9.00 Hz,and the amplitude was 2.65 mm,the eligible rate,replay rate,and hole rate could reach 93.56%,3.35%,and 3.09%.The experimental results were generally consistent with the predicted values.The research confirmed that the air-blowing and vibrating supply seed tray could improve the eligible rate while reducing the vibration frequency and amplitude of the vacuum-vibration tray precision seeder.It also provided a necessary basis for precision seeding technology.