Precision Seed Metering Device Research Articles

Design and experiment of a six-row air-blowing centralized precision seed-metering device for Panax notoginseng.

Panax notoginseng is grown mainly in Yunnan Province. Under the present high-density planting patterns for the plant, to solve the problems of a high rate of seed damage and the inability to use a traditional single air-blowing metering device, this paper designs a six-row air-blowing centralized precision seed-metering device for P. notoginseng to realize mechanized precision seeding of this species. This paper describes the working principle of the seed-metering device, and the main structural parameters are determined by combining theoretical calculations with simulation analysis. A mechanics model of the seed filling, cleaning and pressing processes of the seed-metering device was constructed. The seeds of P. notoginseng in Yunnan Province were selected as experimental subjects. An experimental study on the seed-metering performance of the seed-metering device was carried out using the quadratic rotation orthogonal combination test method. The outlet pressure of the air nozzle, forward velocity and cone angle of the hole were selected as test factors. Mathematical models of the grain spacing qualified index, miss index, multiple index and the coefficient of variation of the row displacement consistency were established to analyze the order of factors affecting indicators. Through parameter optimization, the optimum combination of parameters was determined as follows: the cone angle of the hole is 50°, the forward velocity is less than 0.73 m/s, and the outlet pressure of the air nozzle is 0.32-0.52 kPa. The qualified index of grain spacing is higher than 94%, the miss index is less than 3%, the multiple index is less than 5%, and the coefficient of variation of the row displacement consistency is less than 5%. The test results are essentially consistent with the optimization results. The metering device meets the requirements of precision seeding of P. notoginseng. This study provides a basis for the design of a six-row air-blowing centralized precision seed-metering device for P. notoginseng. Keywords: Panax notoginseng, air blowing, seed-metering device, optimization design, air distribution mechanism DOI: 10.25165/j.ijabe.20201302.5161 Citation: Lai Q H, Sun K, Yu Q X, Qin W. Design and experiment of a six-row air-blowing centralized precision seed-metering device for Panax notoginseng. Int J Agric & Biol Eng, 2020; 13(2): 111–122.

Numerical simulation of particle motion characteristics in quantitative seed feeding system

High-speed precision seed metering device is the key to achieve efficient and precise seed planting in agricultural industry. In this work, a novel quantitative seed feeding system containing a feeding device and a venturi feeding tube is investigated using the coupled CFD and DEM approach. The flow behavior of seed particles and airflow field in this system are analyzed in detail, and the effects of different variables related to venturi tube and operations are examined. The results show that as the nozzle convergence angle increases, the pressure at the nozzle gradually decreases and the pressure gradient extends. As a result, particle movement mobility is enhanced and particle accumulation is reduced. With the increase of the feeding angle, seed particles tend to deposit and collide with the bottom wall. The results also show that when wind pressure reaches above 10 kPa, the spacing between two adjacent seed particles is more consistent, and seed particles are more uniformly discharged from the venturi tube. The results demonstrate that for a better design of the quantitative seed feeding system, the proper nozzle convergence angle is roughly at 70°, and the feeding angle is at around 45°

变粒径气力滚筒式豆类种子精量排种器的设计与实验

The roller for seeds of different sizes, a variable-size pneumatic cylinder precision seed metering device was designed, which could realize the precision seeding of different diameter seeds without changing the roller. The structure and working principle of seed metering device were explained, and the structural parameters of the main components of the seed meter were determined. The ANSYS was used to analyse the influence of the size of the negative pressure inlet pipe and the shape of the eyelet on the airflow velocity in a negative pressure chamber. Based on the above optimal structure, the orthogonal experiment of seed metering device was carried out. Testing results showed: under the negative pressure of 4 kPa, roller speed of 16.93r/min and the wind speed of 11.48m/s, the seed metering device had the best seeding effect. The qualification rate of the seed metering device was 92.37%, the miss-seeding rate was 3.74% and the over-seeding rate was 3.88%.

Design and experiment of a six-row air-blowing centralized precision seed-metering device for Panax notoginseng

Panax notoginseng is grown mainly in Yunnan Province. Under the present high-density planting patterns for the plant, to solve the problems of a high rate of seed damage and the inability to use a traditional single air-blowing metering device, this paper designs a six-row air-blowing centralized precision seed-metering device for P. notoginseng to realize mechanized precision seeding of this species. This paper describes the working principle of the seed-metering device, and the main structural parameters are determined by combining theoretical calculations with simulation analysis. A mechanics model of the seed filling, cleaning and pressing processes of the seed-metering device was constructed. The seeds of P. notoginseng in Yunnan Province were selected as experimental subjects. An experimental study on the seed-metering performance of the seed-metering device was carried out using the quadratic rotation orthogonal combination test method. The outlet pressure of the air nozzle, forward velocity and cone angle of the hole were selected as test factors. Mathematical models of the grain spacing qualified index, miss index, multiple index and the coefficient of variation of the row displacement consistency were established to analyze the order of factors affecting indicators. Through parameter optimization, the optimum combination of parameters was determined as follows: the cone angle of the hole is 50°, the forward velocity is less than 0.73 m/s, and the outlet pressure of the air nozzle is 0.32-0.52 kPa. The qualified index of grain spacing is higher than 94%, the miss index is less than 3%, the multiple index is less than 5%, and the coefficient of variation of the row displacement consistency is less than 5%. The test results are essentially consistent with the optimization results. The metering device meets the requirements of precision seeding of P. notoginseng. This study provides a basis for the design of a six-row air-blowing centralized precision seed-metering device for P. notoginseng. Keywords: Panax notoginseng, air blowing, seed-metering device, optimization design, air distribution mechanism DOI: 10.25165/j.ijabe.20201302.5161 Citation: Lai Q H, Sun K, Yu Q X, Qin W. Design and experiment of a six-row air-blowing centralized precision seed-metering device for Panax notoginseng. Int J Agric & Biol Eng, 2020; 13(2): 111–122.

Design and Test of a Double-Curved Guiding Groove for a High-Speed Precision Seed-Metering Device

HighlightsThe instability of the seed release point in a seed-metering device is proved theoretically.A double-curved guiding groove at the seed-release point improves the seed-metering uniformity.A discrete element model was used to examine effects of the design parameters on the metering performance.The critical parameters for the double-curved guiding groove design were determined.Abstract. The instability of the seed release point in a seed-metering device is one of the main causes of the non-uniformity of seed spacing. To improve the seed spacing uniformity, a double-curved guiding groove (DGG) was designed based on the prerelease adaptive principle. The DGG was used at the seed release point of an existing high-speed precision soybean seed-metering device with a double-setting plate. The results showed that the prerelease curved surface of the DGG was capable of guiding seeds to be released at the same seed release point at all times, and the adaptive curved surface of the DGG prevented any changes in seed velocity caused by friction or collisions between seeds and the meter, thereby improving the seed spacing uniformity significantly. A discrete element model was developed and validated with laboratory tests. Through simulations using the model, the primary and secondary factors of the DGG impacting the qualified rate of seed metering (QRM) and the coefficient of variation of the seed spacing uniformity (CVU) were identified and were, in descending order, the spacing of prerelease (SPR), the starting position of prerelease (SPP), the inclination angle of the seed outlet (ASO), and the inclination angle of the receiving cup (ABR). Regression equations of the QRM and CVU with the two main impacting factors were then established. For a planter travel speed of 10 km h-1, the optimal SPR was 10 mm, and the optimal SPP was 40°, where the QRM was 100% and the CVU was 16.61%. When compared to seed metering without the DGG, the CVU was reduced by 2.55%, showing that the DGG significantly improved the uniformity of seed spacing. Keywords: Double-curved guiding groove, Discrete element method, Seed-metering device, Travel speed, Uniformity.

DEM-CFD coupling simulation and optimization of an inside-filling air-blowing maize precision seed-metering device

Simulation of the gas-solid flow in an inside-filling air-blowing maize precision seed-metering device was performed by means of a coupling approach of the discrete element method (DEM) and computational fluid dynamics (CFD). In this model, EDEM software was used to depict the discrete particle phase, and ANSYS Fluent software was used to describe the continuous gas phase. Maize particles were created by EDEM software using the bonded particle model (BPM) to define a single structure of the particles. Effects of the positions, the width and the average arc length of the lateral hole were examined and analyzed in terms of gas field and seed movement. Using an orthogonal experimental design, the primary and secondary factors and parameters of the maximum evaluation index affecting the working performance of a seed-metering device were assessed. The superiority of a lower position of the lateral hole was identified, as both the width and the average arc length of the lateral hole had no effect on the drag force or differential pressure. The area of the lateral hole significantly affected the movement and airflow field of seeds in the hole of a seed-metering device. The drag force, the differential pressure and the pressure loss increase with the expansion of the area of the lateral hole also resulted in a decrease in the upper pressure. The optimized lateral hole, which is 1.5 mm wide and has an average arc length of 10 mm when the position is lower, had a good working performance, with less pressure loss, superior drag force and differential pressure. The qualified rate of the optimized seed-metering device was greater than 93% when the working pressure was above 5.5 kPa with a working speed lower than 10 km/h through experiment. The results showed that the DEM-CFD coupling approach was a reliable instrument for simulating the physical phenomenon of seed movement in the airflow field. DEM-CFD coupling simulation of seed movement can provide a theoretical basis for assessment of the potential working performance of an inside-filling air-blowing seed-metering device.

Simulation and verification for seed-filling performance of cell wheel precision seed metering device based on discrete element method

The cell wheel seed metering device was improved and a stirring seed-filling device was added to improve the seed-filling performance of cell wheel pseudo-ginseng precision seed metering devices. Using pseudo-ginseng seeds in Wenshan Prefecture, Yunnan Province as the objects for seed metering, the software application EDEM was adopted based on the discrete element method for the simulation calculation and analysis of the seed-filling performance of the seed metering device under 4 rotational speeds of the cell wheel and 6 rotational speeds of the stir wheel. The simulation results indicate that the filling ratio increases as the rotational speed of the stir wheel increases under a constant rotational speed of the cell wheel. Test verification of the simulation analysis results was conducted on the test bed of the seed metering device. The results indicate that increasing the rotational speed of the stir wheel can obtain a filling ratio of over 90%. The test results display a similar variation trend to that of the simulation analysis with an error of average filling ratio less than 5%. Therefore, it is feasible to analyze the seed-filling performance of the stirring and seed-filling device of the seed metering device with the discrete element method.

Development and evaluation of electronically controlled precision seed-metering device for direct-seeded paddy planter

An electronic experimental set-up was developed to evaluate three seed-metering mechanisms, viz. slanting, semi- circular and rectangular shape for three paddy varieties and to investigate the influence of the selected levels of variables, viz. forward speed, cell shape and inclination of seed-metering plate on performance parameters of seed- metering. Mean seed spacing, miss index and seed damage were found to increase with increase in forward speed and angle of inclination while multiple index decreased with increase in forward speed and angle of inclination for all metering plates tested. Precision decreased with increase in forward speed and with increase in angle of inclination, it increased initially up to optimum value and then decreased. The mean seed spacing of 14.8 cm close to theoretical seed spacing of 15 cm, highest quality feed index of 88.1%, lowest miss index of 6.1% and minimum seed damage of 0.38% were observed in slanting type metering plate at an angle of 35º with the horizontal and at a forward speed (belt speed) of 2 km/h. Hence, for design of precision paddy planter, the optimum parameters, like slanting type metering plate with angle of inclination 35º and forward speed of 2 km/h can be used to achieve best results.

Design and Experiment of Swallow line Wheat Precision Seed-metering Device

In order to improve wheat seeding uniformity, a 7.5 cm rows-spacing seed-filling groove style precision seed-metering device is designed to replace traditional external groove-wheel seed-metering device. Size and number of seed groove, upper curve of curb plate to transfer seed, upper curve of blocking plate to clear seed and the diameter and width of seed metering wheel parameters are analyzed and computed. Field experiment of the seeder indicates that 7.5 cm row-space seeder seeds more uniformitier compared with the 15 cm row-space seeder in the same seeding amount. Primary and secondary roots number of seedlings of 7.5 cm row-space is relatively large. It had stocky stem and high tillering ability. By estimation yield, the yield of 7.5 cm rows-spacing increases 8.9% more than 15 cm rows-spacing.

Experimentation Research and Design of Circular Tube Slit Pneumatic Precise Wheat Seed-metering Device

In order to solve problems that traditional mechanical wheat seed-metering device has defects such as poor seeding uniformity and consistency, instability and high seed-injuring rate, a kind of pneumatic wheat precision seed-metering device is designed. The seed-metering device with internal and external circular tube grip seeds in vertical slit of the external circular tube by the negative pressure of the internal circular tube. We optimized slit width, rotating speed and negative pressure of the seed-metering device by the orthogonal experiment. In the field, we did contrast experiment through contrasting the existing mechanical seeder for wheat and measured and analyzed seeding uniformity, seedling emergence rate, consistency of each line seeding quantity, stability of total seeding quantity and rate of damaged seeds of the seed-metering device. The experiment data shows its each seed distance variation coefficient increases more 20% than current domestic mechanical wheat seed-metering device and its seeding uniformity gains obvious improvement.

Design and experimental study of the control system for precision seed-metering device.

The precision seeding technique has been developed at full speed along with the continuous development of new agricultural technologies, especially those concerning cultivated patterns. The seed-metering device is the key component of a precision seeder. A ground wheel is used to drive the seed-metering device of the conventional direct seeder. However, the wheel bears high resistance and easily slips. Moreover, the adjustment of the precision seeder’s seeding rate is more difficult. In order to solve these problems, a control system which could keep the rotational speed of the seed-metering device consistent with the seeder’s working speed for the precision seed-metering device was designed. The control system includes a Hall sensor, a single chip microcomputer system, a motor control module, a stepper motor and a display. The control system used a Hall sensor to measure the seeder’s working speed and employed a single chip microcomputer system to predict the rotational speed of seed-metering device. It would then determine the relationship between the seeder’s working speed and the rotational speed of the seed metering-device according to the seeder’s working state, distance between seeds and the requirement of sowing rate. The system could effectively reduce the influence of inhomogeneous sowing caused by the ground wheel’s slipping. The system was found to be reliable by the experiment. The seeding control system could also make the speed of the seed-metering device and seeder’s uniform, improving the uniformity of the amount of seeding, and achieving the goal of design. This new design provides a platform to solve problems of the seed-metering device and the seeder. Keywords: agricultural machinery, precision seeder, seed-metering device, sensor, control system, stepper motor DOI: 10.3965/j.ijabe.20140703.002 Citation: Zhai J B, Xia J F, Zhou Y, Zhang S. Design and experimental study of the control system for precision seed-metering device. Int J Agric & Biol Eng, 2014; 7(3): 13－18.

Design on Multifunctional Water-Saving Mulch Planter

In order to improve the seeding efficiency and quality of water-saving mulch planters, a kind of multifunction mulch planter with laying irrigation tape was designed based on duckbill type precision seed metering device. It broke the pattern of single planting machine and realized duplex joint seeding operations. The seeding and film mulching performance were also improved by optimizing the seed metering device and film laying device. The planter has the characteristics of simple operation, less investment, reliable performance and good film-mulching result. The result of field test showed that: the average seed space is 150mm; the working speed is 4.3km/h; the pass rate of grain distance is 96.7%; the vacancy rate is 0.8%, the pass rate of seed number is 99.2%. So the sowing quality of the planter is well.

Experimental Research on Belt Type of Precision Seed-Metering Device

Based on the fact of low single seed plant rate, high seed damaged rate and low seed adaptability for conventional and mechanistic precision seed-metering device, a new belt type of seed-metering device was designed (patent No.20101020638.7). both of the 1/4 spherical shape and its size was first established by analyzing the working process of the seed-metering combination the material character of the tested corn seed, and the structure size 6mmX6mm of the seed scoop of this type of seed-metering was then determined by the frame test in agricultural lab, which was tested to own the good work performance. At last, the working adaptability tests were operated, the conclusion showed that the following character indexes were single seed plant rate 98.6%, repeated plant rate 6.3%, leakage plant rate 0.8% and seed damaged rate 0.05% when the size of seed-scoop is 8mmX12mm and the belt speed is1.05 m/s.

Numerical Simulation and Experiment of Motion of Rice Seed in Pneumatic Seed-Metering Device

A new-style pneumatic precision seed-metering device for super rice seed was proposed. This paper analyzed the working process for seed-metering device. The movement of rice seed in the “L” tube was simulated by finite element analysis software. The speed distribution, pressure distribution of air in the “L” tube and the trajectory of rice seed were solved. Results of the analyses indicated that there were partial reflux at the entrance and elbow; while the airflow moved steadily at the straight pipe. Based on the fabricated device, the motion trajectory was studied by high speed video camera. Experiment was used to analyze the effect of parameters. The results showed that the experimental trajectory was in accordance with theoretical models.

Simulation Analysis of Seed Metering Procedure in Scoop Metering Device Based on Discrete Element Method

Seed metering procedure of metering device was a key factor to affect performance of precision seed metering device. Based on analysis of seed holding volume of metering scoop, relationship between the seed holding volume and structure parameters of the metering scoop was established, and beginning and ending angles of seed clearing during the seed metering procedure were determined. Simulation analysis of seed metering procedure with different parameters of the metering device was carried out by mean of discrete element method to identify the influences of metering scoop parameters on the performance the metering device, and suitable range of structure parameters of the metering scoop were investigated. Finally, the reasonability of design parameters of the metering scoop for experiment usage was verified.

벼 직파용 정밀 배종장치 개발

In order to save labor and cost, direct seeding has been considered as an important alternative to the machine transplanting in rice cultivation. As current seeders for direct seeding of rice seeds drill irregular amount of seeds under various operating conditions, conventional drilling should be turned to precision planting which enables accurate placement of proper amount of rice seeds at equal intervals within rows. In this study, design, construction and performance evaluation of a precision seed metering device for planting of rice seeds were carried out. As prototype, the conventional roller type seed metering device was modified for planting: increasing diameter of metering roller, setting 2 or 4 seed cells on metering roller, adding seed discharging lid and its driving cam mechanism. Through performance tests for prototype and the current seed metering device, number of seeds in a hill, planting space and its error ratio, coefficient of variation of planting space (planting accuracy), and seeding length of <TEX>$90\%$</TEX> of seeds in a hill divided by planting space (planting precision) at setting planting spaces of 15, and 20cm, seeding heights of 10, and 20cm, and seeding speeds of 0.1, 0.2, and 0.5m/s were investigated. Prototype showed better seed planting performance than the current seed metering devices. When setting planting space of 15 cm and seeding height of 10cm, prototype with 2 seed cells showed that variations of planting space and seeding lengths of <TEX>$90\%$</TEX> of seeds in a hill at up to seeding speed of 0.5m/s were within 0.9cm, and 3.6cm, respectively.

PRECISION SEED METERING WITH A SUBMERGED TURBULENT AIR-JET

ABSTRACT A precision seed metering device consisting of a submerged turbulent air-jet directed at an artificial turf barrier has been developed and tested. As the air-jet passed through a seed mass, individual seeds were picked up and held against the barrier. Critical surface characteristics of the barrier included deformability and porosity. When metering sized seed-corn with a vertical plate system, a 1.6 mm (0.063 in.) jet nozzle, and supply pressure (gage) of 30 to 40 kPa (4.4 to 5.8 psi), theoretical drops of approximately 100% were achieved. Similarly, 100% theoretical drops were possible for individual soybeans at supply pressures ranging from 20 to 25 kPa (2.9 to 3.6 psi). Metering rate increased as supply pressure increased and plate speed decreased.