Experimental study on the performance of bowl-tray rice precision seeder

In order to optimize the parameters of bowl-tray rice precision seeder and improve its performance,three major factors respectively at five levels,including shaped hole diameter,vertical displacement of rice seeds and rotating speed of cam,were tested,the quadratic orthogonal rotational regression experiments were conducted,and the effects on seeding rate,leakage sowing rate and the injury rate were investigated.The test results show that factors affecting rice seeding rate are in the order of shaped hole diameter,rotating speed of cam and vertical displacement of rice seeds.The factors affecting rice planting leakage rate are in the order of shaped hole diameter,vertical displacement of rice seeds and rotating speed of cam,and the factors affecting rice injury rate are in the order of rotating speed of cam,vertical displacement of rice seeds and shaped hole diameter.Optimal parameters(shaped hole diameter:10 mm,vertical displacement of rice seeds:27 mm,rotating speed of cam:13 r/min)and performance index(seeding rate:95.43%,leakage sowing rate:0.37%,injury rate:0.58%)provided the basis for design and performance improvement of the bowl-tray rice precision seeder.

Experimental study on seed-filling performance of maize bowl-tray precision seeder

According to the requirement of assorted maize transplanting machine,a maize bud-seed precise sowing device was presented for use in cold areas.Experiments were performed to optimise the parameters of a maize bowl-tray precise seeder to improve the seed-filling performance.When the diameter of brush seed wheel was 78 mm,the clearance of brushing seed was 3 mm,with the maize varieties Demeiya 1,the moisture content about 40%,the depth of shaped hole 6 mm,the two major factors,the diameter of shaped hole and the velocity of seed box,were tested at five levels for each factor using the orthogonal rotational regression experiment.The effects on the single-seed rate,multi-seed rate,empty-seed rate,broken-bud rate and damage rate were investigated.The test results indicated that the factors affecting the single-seed rate and the multi-seed rate were the diameters of shaped hole and the velocity of seeds box,and the factor affecting the empty-seed rate was primarily the diameter of shaped hole.This study determined the optimal parameters,and verified the results,which provide the basis for the design and performance improvement of the maize bud-seed bowl-tray precision seeder.

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.

Design and experiment of multi-row pneumatic precision metering device for rapeseed

The main objective of this study was to design a pneumatic disk with four-rows for planting rapeseed and to investigate its performance under several rotating speeds and vacuum pressure values.The effects of rotating speeds,vacuum pressure and rows on seed sucking and retaining were inspected.Six rotating speeds(5 r/min,10 r/min,15 r/min,20 r/min,25 r/min and 30 r/min)incorporated with the application of vacuum pressure were employed for detecting the optimum vacuum amount that was sufficient for seed sucking under each speed.These values of vacuum were found to be 1.1 kPa,1.25 kPa,1.35 kPa,1.65 kPa,1.8 kPa and 2.0 kPa,respectively.Moreover,a regression model was developed for predicting of vacuum pressure that corresponds with each rotating speed.Based on seed mass analysis,statistical differences were found at 5%significance under the influence of speeds and negative pressure and existed also between and within rows according to Duncan’s Test.The highest seed mass means of 3.17 g and 3.96 g were obtained by row 1 under the effects of speed and vacuum pressure,respectively,while the lowest means of 2.79 g and 3.05 g were attained by row 4.Due to the influence of rows,important differences were occurred between row 1(closer to the center of rotation)and row 4(farther one),particularly under high speeds(25 r/min and 30 r/min).Results concluded that,pneumatic disk with multiple-rows could be satisfactorily used for seed sowing with a little variation in seed amount between rows without any seed damage.The rows of hole farther from plate center of rotation were obviously influenced by angular velocity and vacuum amount rather than the closer ones.

Review of precision rice hill-drop drilling technology and machine for paddy

Mechanized rice direct seeding is a cost-effective and efficient approach for rice cultivation.Recently,the use of rice direct seeding has been increasing rapidly owing to rural labour shortages and continuous increases in agricultural production costs.This article reviews the research and application progress of mechanized rice direct seeding including direct seeding technologies,precision rice seeding,precision rice seed-metering devices,key supporting agronomy technologies for mechanized rice direct seeding.South China Agricultural University developed precision rice hill-drop drilling(PRHDD)with synchronous furrowing and ridging technology and series machines for paddy that affords remarkable advantages in terms of saving time and labour,higher yield,and higher efficiency.In this approach,pre-germinated seeds are uniformly hill-dropped in the expected positions in puddled soil.It significantly improved the crop growth population and effectively solved the problems of high frequency of disease and pests caused by the irregular distribution of rice seeds with manual broadcasting,and generally reduces seed usage and increases the yield.Therefore,this technology has broad application prospects and great potential for promoting the development of mechanized rice direct seeding in China.

Design and field evaluation of hill-drop pneumatic central cylinder direct-seeding machine for hybrid rice

To meet the requirement of the precision direct-seeding for hybrid rice,this study aimed to design a hill-drop pneumatic central cylinder direct-seeding machine to sow ten rows at a time.A series of orthogonal experiments were conducted to investigate the performance of the cylinder seeder.The influences of the hole diameters,degree of vacuum,and rotational speed of the cylinder were tested on JPS-12 computer-vision seeding test platform,and the rotational speed of 10-50 r/min,diameter of 135 mm and a negative pressure of 1.0-2.0 kPa were employed.Test results showed that the optimal parameter combination was a vacuum of 2.0 kPa and a hole diameter of 2.0 mm(straight hole),with a rotational speed of 30 r/min.The probability of(2±1)seeds in each hole was 95.3%,while the probability of seed-missing hole was 2.0%.A series of field experiments were then conducted to test the seeder performance according to China National Standard Test Methods,and the field test results showed that for the hill-drop pneumatic central cylinder direct-seeding machine,the probability of(2±1)seeds in each hill was 91.6%,while the probability of seed-missing hill was 2.7%.The yield data showed that the average effective panicle had 231.25 ears,the average seed setting rate was 9.92%,the average 1000-grain weight was 22.45 g,and the average yield was 7107.9 kg/hm^(2) that was 26.14%higher than the average yield of rice(5634.9 kg/hm^(2))of Guangdong Province in 2016.The results showed that the hill-drop pneumatic central cylinder direct-seeding machine for hybrid rice could be applied in practical precision rice seeding.

Design of an active seed throwing and cleaning unit for pneumatic rice seed metering device

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.