Search

A high-precision mechanized seeding can greatly contribute to the vegetable production at present. In this study, a spotting glue-paper tape precision seeder was designed for the small seed vegetables, particularly combining the seed rope and printing seeding. Three components were also divided in the seeder, including the peristaltic pump glue, ratchet spotting glue, and seed metering device. Among them, the glue was a mixture of pregelatinized starch and water. Specifically, the glue volume and viscosity were the main factors affecting the number of adhered seeds. The glue point volume depended mainly on the rotation angle of the peristaltic pump during the movement. A pretest of seed adhesion was carried out to preliminarily determine the mass ratio of pregelatinized starch to water (less than 1:5), representing the glue viscosity. Furthermore, the frequency of pump and dispensing were analyzed to clarify the relationship between the peristaltic pump and ratchet speed, where the number of ratchet teeth was determined to be 4. As such, the matching was realized between the peristaltic pump and ratchet spotting glue. The ratchet profile was also designed, according to the spotting glue motion. A theoretical analysis was made on the movement of seeds in the seed guiding tube. It was found that the aggregation effect of seeds on the paper tape relied on the length and cross-sectional angle of the seed guiding tube, as well as the rotation speed of the socket wheel. The seed guiding tube was then optimized for the optimal structural parameters. A Box_Behnken test was also carried out, where the length and cross-sectional angle of the seed guiding tube, while the rotation speed of the socket wheel was taken as the test factors, whereas, the percentage of seeds in the effective area on the paper tape was taken as the test index. The results showed that the percentage of seeds in the effective area on the paper tape was 57.23%, when the length of the seed guiding tube was 56 mm, the section angle was 35°, and the rotation speed of the seed metering wheel was 30 r/min. An adhesion test was also performed on the Shanghai Qing 605 seeds with a diameter of 1.5-2.0 mm. The test factors were then selected as the roller angle of the peristaltic pump and the mass ratio of pregelatinized starch to water. An optimal combination of parameters was achieved, including the size of the glue point, and the mass ratio of pregelatinized starch to water. Once the roller rotation angle was 10° and the mass ratio of pre-gelatinized starch to water was 1:6, the single seed rate of glue point adhesion to seeds reached 97.4%. The adaptability test was also carried out on the whole machine on the working performance of different varieties of small seed vegetables. It was found that the single seed rates of Shanghai Qing 605 and Siji Chinese cabbage seeds were greater than 95% under the working speed of 0.5-1.5 m/s, whereas, the coefficient of variation of plant spacing was less than 10%, fully meeting the requirements of precision sowing indicators that specified in the standard NY/T1143-2006. Therefore, the single seed rate and the working efficiency of the improved seeder increased by 3.53%, and 50% than before. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pregnancy diagnosis is one of the most important links in the reproductive management of meat rabbits. Especially, the early identification of non-pregnant rabbits can advance the re-insemination time, further improving the service rate of breeding rabbits for a shorter reproductive cycle in commercial productions. However, the manual touch diagnosis can present some stress responses of rabbits at present. A non-invasive approach can be an alternative for the early pregnancy diagnosis in the future large-scale production of rabbits. In this study, a non-invasive portable diagnosis device was developed to rapidly and accurately identify the early pregnancy of rabbits using spatial diffuse light. The optical characteristics also presented differently from the gestational sac tissue in the abdomen of pregnant and non-pregnant rabbits. The portable diagnostic device consisted of a sensing probe and a signal processing host with two infrared LEDs (the light-emitting wavelengths of 850 and 930 nm), three silicon-based photodiodes, and peripheral circuits. 130 rabbits were selected to test after 14 days of artificial insemination, including 63 pregnant rabbits and 67 non-pregnant rabbits. The collected data was then divided into the training set and test set, according to the ratio of 7:3. Specifically, the training set was used to establish the partial least squares discriminant analysis (PLS-DA) and support vector machine (SVM) classification model. The test set was used to evaluate the classification performance of the established model. At the same time, the PLS-DA was conducted for the supervised principal component analysis (PCA) and variable importance analysis (VIA) on the sampling data. The results showed that there were great differences between the sampling datasets of pregnant and non-pregnant rabbits, indicating a better classification. Furthermore, it was found that the SVM presented a better classification performance than that of the PLS-DA for the pregnant and non-pregnant rabbits, where the sensitivity, specificity, and accuracy of the test set data were 80.95%, 83.33%, and 82.05%, respectively. Consequently, the developed diagnosis device can be widely expected to rapidly identify the pregnancy of rabbits within 14 days after insemination, indicating a feasible optical pregnancy diagnosis. The finding can provide a strong reference to the early pregnancy diagnosis of rabbits, further enhancing the intelligent level of industrial equipment in rabbit production. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seeding amount determines the distribution density of plants in the field, thereby posing a significant impact on the final yield of crops. Real-time detection of sowing amount is an inevitable trend in precise agriculture. However, the current technology is difficult to rapidly identify overlapping seeds for the total amount of wheat precision seeding. In this study, an accurate detection system with an interpolation sensor was developed to control the seeding amount in a wheat precision planter with a wide seedling strip. Infrared radiation LEDs were used as the sensitive elements, and the 24-bit ADS1256 as the high-precision sampling module. The sampling frequency of the system was determined to be 1×103 Hz. The process of seed falling was analyzed, where the seeds were sampled at least three times when the sensor was scanning over the detection areas. The sampling voltage of one seed, two seeds, and three seeds were obtained when the sensor passed through. Two sampling threshold divisions were set using the peak and the mean value, according to the sampling voltage. In the peak, 489 was the threshold value for 1 and 2 seeds while 616 for 2 and 3 seeds. In the mean, 277 was the threshold value for 1 and 2 seeds while 330 for 2 and 3 seeds. A detection system of precision seeding was realized to integrate with the interaction interface of touch screen personal-computer and drive control of a stepper motor. A field experiment of planter under static state was carried out to verify the detection accuracy of the system, the adaptability for different varieties of wheat and seeding frequency, and further to evaluate the two-threshold division. Three types of wheat were selected as the research objects, including Heng-Guan 35, Ji-Mai 22, and Cun-Mai 11. It was found that the peak detection was optimal, due to the low detection error and good adaptability to different wheat varieties. The peak detection was further revised, where the correction coefficient was 7.08%. A field experiment was also carried out to further verify the performance of the detection system under dynamic conditions. It was found that the absolute detection error of the system ranged from 1.12%~5.63%, and the mean absolute error was 3.12%, indicating a high detection accuracy for the high requirements under various sowing rates and operation speeds, as well as a high resistance to sunlight and dust interference. The finding can provide potential technical support for the design of seed tube sensor, and the rapid detection of seeding amount in the process of precision wheat sowing. [ABSTRACT FROM AUTHOR]

In order to increase the rate of single seed and reduce the missing and multiple rate of the mechanical precision seed-metering device, and from the perspective of reducing the seeds friction in the filling area and increasing the seeds activity, a kind of self-disturbance inner-filling cell wheel maize precision seed metering device was designed. For the mechanical metering device, the process of seeds filling into hole depends more on gravity, because of seed layer thickness is limited, the size of filling gravity will not change too much, and disturbing the seed to a certain extent will cause the seed to produce normal beating, which is not conducive to fill. So a seed disturbing strip on the inner surface of a certain inclined cone disc was designed. The advantage is that the seed on the top of the hole gets a small normal jump to decrease the seed friction, simultaneously it can ensure that the seed gets enough filling force to be filled into the hole. The movement of the seed on the disturbing strip and the principle of seed filling were analyzed, and then the parameter design of the seed metering device was completed. The hole parameters of seed metering disc were calculated, and the optimum hole size for seed filling was determined. Different types of disturbing strip are set on the conical surface of the seed metering disc, which are non-disturbing strip, direct disturbing strip, decline disturbing strip and spiral disturbing strip. The force acting on the seed disturbing strip and the relative limit velocity of the seed filling into hole were analyzed. It was determined that the radius of the seed disturbing strip, the cone angle of the cone and the rotation speed of the seed disc all affected the filling process. In order to determine the optimal seed metering parameters of the seed metering device, a discrete element software EDEM was used to simulate the seed metering device. The single factor test and the multiple quadratic rotation orthogonal combination test were carried out with the test factors of the rotation speed of the seed plate, the strip form of disturbing the seed, the cone angle of the seeding plate and the radius of the disturbing strip. Using Design-Expert 8.0.6 to analyze the test data, the mathematical model between the rate of single seed, missing , multiple sowing and the test index was obtained. The optimum parameters were as follows: The speed of the seed disc was 8.40 r/min, the disturbing strip form was spiral, the cone angle of the seed plate was 38.6°, and the radius of the disturbing strip is 1.24 mm, respectively. The single, multiple and missing rate were 96.29%, 2.55% and 1.15%, respectively. Under the optimal parameter combination, the bench test proved that the of single、multiple and missing rate were 95.4%, 2.55% and 1.15%, respectively. When the speed of the seed disc during 8.40~16.67 r/min, the single rate was more than 91.4%, multiple and missing rate were less than 2.55% and 1.15%, the seed damage rate was less than 0.44%, respectively, and the seeding effect is 3.2% higher than the scoop wheel type metering device. which could meet the agronomic requirements of the precision sowing of maize. The simulation test of the seed metering device based on EDEM discrete element method has provided references for determining the performance parameters of the seed metering device and shortens the design period. This study can provide references for improving the performance of the mechanical seed metering device. [ABSTRACT FROM AUTHOR]

Precision seeding of rice is key technology to achieve the modernization of rice cultivation. At present, most seeding precision of rice in China is 1 to 7 per hole, which is hard to achieve the requirements of seeding precision. A cell-belt type precision seed-metering device based on friction and repeated filling principle was developed aimed at meeting the production requirement of sowing (2±1) seeds into per hole to solve the problem on the precision seeding of low sowing quantity for hybrid rice seedling production. Structure and working principle of the cell-belt type precision seed-metering device was described, and the result showed the feasibility of precision of the seed-metering device. Structure size of key components was analyzed, included the shape and dimensions of cell, the distribution of cell, the dimensions of cell-belt. The mechanics and kinematics on seed-filling processing mechanism was analyzed, from which the filling conditions was found out. And the factors influenced the filling performance was received, including the angle of cell, velocity of the cell-belt and thickness of seed layer. And this provided theoretical basis for the design of metering device. With the consideration of the motion direction, the resistance and the processing difficulty, the directional angle of cell was designed as 90°, which meant the direction of the long side of the cell was in accordance with the motion direction of the belt. Multiple and repeated seed filling process was simulated. And the single factor tests on the effects of cell-belt velocity, cell-belt inclined angle and seed layer thickness on seed filling performance was performed by EDEM software. It showed that: the leakage rate decreased first and then increased as the increases of the cell-belt velocity; the circulation layer formed and the range of it became larger gradually as increasing the seed layer thickness, which caused the longer of the filling interval and could decrease the leakage rate; the filling interval decreased and leakage rate increased as increasing the cell-belt inclined angle. On this basis, the prototype device was designed in accordance with the parameters of the metering device. According to the tests and the analysis based on the simulation, the optimal conditions were selected for experimental verification. The optimal parameters combination of the cell-belt inclined angle, cell-belt velocity and seed layer thickness was 43°, 0.11 m/s, 50 mm, respectively. The text response parameters of the result were the seed-filling qualified rate (the rate of sowing (2±1) seeds into per hole), the multiple seed rate (the rate of sowing >3 seeds into per hole) and the leakage rate (the rate of sowing 0 seed into per hole), respectively. The result was that: The seed-filling qualified rate, the multiple seed rate, the leakage rate were 96.4%, 1.4% and 2.2%, respectively. Under the same condition, the crushing test was done, and the average of 3 tests result showed that the broken rate was 0.18%, which was enough for the practical production. The cell-belt rice precision seed-metering device based on friction and repeated filling principle could meet the requirements of precision seeding. The research results provide a reference for the design of precision seeding machine for factory plug seedlings. [ABSTRACT FROM AUTHOR]

Fertilizing operation is an important link in grain seeding, which plays an important role in ensuring the high yield. Fertilizer spreaders often are used in the operating process. At present, the spreading uniformity of most of the machines needs be improved. In order to improve the spreading performance, in this study, a centrifugal fertilizer spreader with a rotating swing disk with 16 involute spiral guide rails was studied and dynamic characteristic analysis of fertilizer particle was performed. A single factor simulation analysis on rotational speed of disk, feeding angle, feeding quantity and angle of feeding position was conducted using a disk rete element model based on theoretical analysis results. Influence of various factors on the spreading uniformity of the centrifugal swing disk was discussed. The working range of the parameters was derived. The rotational speed of disk ranged from 700 r/min to 1 100 r/min, feeding angle was from 70° to 110°, feeding quantity was from 2 000 particles to 6 000 particles per sencond, and angle of feeding position was from 50° to 90°. The urea with larger size was taken as the research material. The orthogonal regression rotation simulation experiment with four influencing factors was designed and the test indexes were coefficient of variation of fertilizer distribution on the lateral width direction. The simulation experiments on fertilizer spreading performance and target parameter optimization was done, and the static verification test was carried out. Multivariate nonlinear regression model was established and the affecting importance of factors on the uniformity and response surface analysis was finished. The experimental data were processed and optimized by Design-expert 8.0.6. The results showed that the interaction between angle of feeding position and rotational speed of disk, angle of feeding position and feeding angle had important influence on spreading uniformity. The order of importance was followed by rotational speed of disk, feeding angle, feeding quantity and angle of feeding position. The minimum uniformity coefficient of variation were 12.48% when rotational speed of disk, feeding quantity, feeding angle and angle of feeding position was 900 r/min, 4 275 per second, 110° and 64°, respectively. With the optimal parameters, the results of simulation and bench testing were mostly in agreement. The simulation research on fertilizer spreading performance of fertilizer spreader by EDEM was proved to be feasible. In order to verify operating effect under actual working conditions, the dynamic simulation research of multi-track fitting and superposition was carried out. The results showed that uniformity coefficient of variation were 9.92% and 11.43%, respectively when the forward speed of a machine was 0.5 m/s and 1.5 m/s. The fertilizer spreader can meet the technical requirements of field operations. The centrifugal fertilizer spreader with a rotating swing disk provides better working performance. The research results provide a theoretical reference for design and optimization of the granular fertilizer spreader with a spinning swing disk. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the process of discrete element numerical calculation, the establishment of the particle model is an important factor to affect the accuracy of the simulation.It is necessary to establish the 3-D models of irregular grains for discrete element method whose morphology is approximate to the real grain to analyze and simulate the main working process like precision seeding and precision selecting and classifying seeds.At present, an irregular particle with complex contours is simplified into the regular shape to model, which can lead to reduction of the simulation accuracy. In order to improve the accuracy of the dynamic simulation of the irregular particles, a method of modeling 3-D DEM models was proposed for irregular shape particles like rice grain based on 3-D laser scanning.Five hundreds of Kongyu 131 (rice cultivar) rice seeds were chosen randomly and scanned using CF-30 automatic high precision 3-D scanner.The size distribution of length, width and thickness is in accordance with the normal distribution and the average length, average width and average thickness of the three-dimensional measurement were 7.0 mm, 3.5 mm and 2.4 mm, respectively.The rice seed with the average three-dimensional sizes was scanned and the polygonal contour model and space coordinate information were obtained by the process of treating color, noise removal, point cloud registration, point cloud triangulation, consolidation and model modification using the reverse engineering software Geomagic Studio.The polygonal contour model was imported into SolidWorks and the 3-D DEM model with complex contour of the rice seed based on 3D laser scanning was created by inverse modeling.The 3-D DEM model of the rice seed based on 3D laser scanning was filled by 87 balls particles based on the theory of polymer particles, which was named as Model1.The 3-D DEM model of the rice seed with the same three-dimensional sizes as Model1 was processed usually as regular ellipsoid, which was named as Model 2.In order to test the simulation accuracy for discrete element method of the modeling method of irregular particle based on 3D laser scanning, the simulation prediction of repose angle for Model 1 and Model 2 was done respectively using the discrete element method software EDEM.The repose angle of the Model 1 and the Model 2 were 29.77° and 27.08°, respectively.And the repose angle of the actual rice seeds was measured under the same condition as the simulated experiment condition for comparative analysis.The experimental result of the repose angle was 29.70°. And the measurement errors between the simulation results by two modelling methods and the actual experiment value about repose angle were 0.24% and 8.83%, respectively.The repose angle obtained by Model 1 based on 3-D laser scanning was closer to not only the experimental measured value but also accumulation form, and there was a big error between that by Model 2 based on the usual treatment as regular ellipsoid and the experimental result, which showed that the modeling method of irregular particle for discrete element based on 3-D laser scanning was validated and available.This paper provides a new means to improve simulation precision of irregular particles for discrete element method. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)