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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.)

Grapes can be cultivated in the cold areas of northern China. The cold-proof soil clearing has been the typical operation to prevent the freezing damage under the cold climate. Among them, the flexible roller is one of the most important components for the spring soil-clearing operation in northern grapes. The operating parameters have also posed a great impact on the performance of soil clearing. The numerical simulation can normally be used to optimize the operating parameters for the flexible soil-clearing roller. However, the overall modeling is confined to the harsh requirements so far, such as the large computational volume, long computation duration, and high configuration. In this study, a partial modeling of parameters was proposed to predict the whole one, in order to significantly reduce the cost of simulation calculation. Firstly, the minimum structure feature was extracted from the flexible soil-clearing roller. A prediction model of the overall performance was then constructed using the geometric similarity. Secondly, the minimum feature model of structure-soil interaction was established for the optimal operational performance using the coupled Discrete element method (DEM), and Multi-flexible-body dynamics (MFBD). Finally, the overall performance of the flexible soil clearing-roller was estimated using the prediction model. The results showed that a strong linear correlation was found in the linear fit R² values of 0.987, and 0.993 between the soil clearing rate and resistance torque of the flexible soil clearing-roller with the brush piece number, respectively. It infers that the linear model was used to accurately describe the relationship between the overall and partial performance. A series of finite element models (FEM) were established for the rubber sheet with the solid 10 cells and the damping ratio 0.005, while the brush wire with the solid 4 cells and damping ratio of 5×10-4, and the brush blade with the array density 90 of brush wire. The relative errors were 8.43%, and 1.52% for the simulation and physical measurements, respectively, for the minimum feature structure of the soil clearing rate and resistance torque in this case, indicating the excellent consistence with relatively small ones. Once different numbers of brush pieces were added, the maximum relative errors were 8.43%, and 10.53%, respectively, indicating the accurate and reliable model. Meanwhile, the contact calculation volume of the partial modeling was only about 8% of the overall modeling, which was effectively reduce the simulation calculation cost. Furthermore, an optimal combination was achieved, with the forward speed of 0.3m/s, the mounting angle of 30°, the axial length of 50mm, and the blade taper angle of 0°. The significant effects were also found on the operational performance of the minimum feature structure and brush piece. Specifically, the soil clearing rates of the whole and single brush piece were 36.87%, and 2.80%, respectively, whereas, the resistance torques were 18.91 and 2.78 N·m, respectively, for the minimum feature structure under the optimal condition. The relative errors were 3.74% and 10.15% between physical and simulation of the minimum feature structure under the same conditions, where the relative errors of brush piece were 10.36%, and 9.71%, indicating the accurate and reliable simulation optimization. Anyway, the soil clearing rate and resistance torque were 97.07%, and 78.68 N·m, respectively, for the flexible soil-clearing roller that estimated by the prediction model. The relative errors between the physical and the predicted were 7.84%, and 4.55%. The relative errors between the optimized by the overall modeling and the predicted were 10.66%, and 6.76%, indicating the partial modeling with the high feasibility and accuracy. The findings can also provide a new idea for the interaction modeling between the complex flexible bodies and bulk particles. [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.)

A furrow planting has been widely used for the large-scale vineyards in the Xinjiang of western China. A cold-proof cloth with the buried soil in-furrow planting has posed a great challenge on the spring soil clearing operations for grapes. The recycling of cold-proof cloth is also confined to a large amount of covering soil during the spring soil clearing. The breakage of cold-proof cloth can easily occur when directly pulling the cold-proof cloth between the rows during winding. It is necessary to clear the covering soil above the cold-proof cloth, in order to reduce the cold-proof cloth wind. In this study, a soil clearing device with a horizontally flexible brush roll was developed to remove the covering soil above the coil-proof cloth. Six factors were determined for the operation ranges for better performance, including the forward speed of the machine, the rotation rate of soil clearing assembly, the installation angle, the axial length of the anti-blocking device, the blade declination angle and the blade taper angle. Furthermore, a multi-body dynamics software RecurDyn was used to establish a finite element (FE) flexible body model for the soil clearing assembly, where the cell type was tetrahedral cells. At the same time, a discrete element software EDEM was selected to establish the soil ridge model, whereas, the EDEM-RecurDyn coupled simulation was utilized to establish the soil clearing assembly-soil interaction model for the operation process of soil clearing. A Plackett-Burman simulation was also conducted to select the four factors with the most significant impact on the operating performance, where the soil clearing rate and torque were taken as the test indicators. Then, a Box-Behnken experiment was designed, where the four factors with three levels for each factor. A quadratic regression model was then established for the soil clearing rate and torque. A systematic optimization was implemented, where the maximum soil clearing rate and the minimum torque were taken as the optimization objectives. An optimal combination of parameters was achieved as follows: the forward speed of the machine was 0.3 m/s, the rotation rate was 550 r/min, the installation angle was 30°, blade declination angle was 0°. These optimal parameters were used for the field tests, where the soil clearing rate and torque were 84.12% and 78.62 N·m, respectively, and the relative errors with the simulation and optimization were 3% and 7.2%, respectively. The finding can provide a promising technical reference to design the flexible components of soil clearing in vineyards. [ABSTRACT FROM AUTHOR]

Weeds have generally seized the growth resources of grapes, resulting in the aggravation of plant diseases and insect pests for the reduced grape quality, particularly the yield reduced by 10% to 20%. Therefore, weed removal is one of the most important steps in the vineyard. The current obstacle avoidance system in an automatic obstacle avoidance weeder can be operated bilaterally in the hedge-frame grape cultivation. Most obstacle avoidance action was controlled by the switches, where the obstacle avoidance stroke was fixed. However, a relatively low effect of weeding often occurred, due mainly to the obstacle avoidance action stroke cannot be accurately controlled, according to the position of obstacles. In this study, a highly precise control system of obstacle avoidance was optimized to design in an interplant weeding machine, according to the principle of copying control. The specific system consisted of the signal acquisition of obstacle avoidance, program control, hydraulic actuator, and the obstacle avoidance monitoring feedback part. A closed-loop control system was also composed of signal acquisition, hydraulic actuator, and monitoring feedback part, according to the requirements of precise obstacle avoidance. The signal acquisition of obstacle avoidance was run to collect the angle change of signals ∆β in real time when the weeding cutter moved to the position close to the obstacle. A voltage signal was then converted to transmit for the control system. The theoretical action stroke of the hydraulic actuator was calculated by the control system, where the signal was converted and output to the hydraulic actuator in the θ Angular variation ∆β size. At the same time, the displacement sensor of obstacle avoidance monitoring feedback transmitted the actual action stroke to the control system for the precise adjustment of the action stroke of the hydraulic cylinder. The structure of the hydraulic circuit was optimized to realize the precise control of obstacle avoidance under the combination of hydraulic and electronic control. Static calibration was carried out for the precise control program of obstacle avoidance. Specifically, the effective stroke range was 5-145 mm for the calibration hydraulic cylinder and the feedback displacement sensor, and the effective stroke of the signal acquisition displacement sensor was 0-70 mm. PID parameters were set in the control program at the speed of 440 mm/s, where the optimal PID parameters were finally determined as P=0.034 3; I=127.78; D=0. The target center distance curve of the hydraulic cylinder was well fitted to the actual center distance curve, indicating an accurate, quick and stable implementation of the obstacle avoidance process. Recurdyn was used to simulate the precise obstacle avoidance operation in a weeding machine under the condition of straight obstacles. The coverage rate of the weeding operation was calculated to analyze the movement track of the weeding cutter disc. An optimal speed of the weeding cutter disc was selected as 200 r/min. Taking the operation speed of the machine as the experimental factor, the weeding coverage rate, and the damage rate of the fruit tree as evaluation indexes, field tests were carried out in the Scientific Research Test Base of China Agricultural University Zhuozhou, Hebei Province in June 2021. The results were as follows: The average coverage rate of weeding was 94.82%, 94.36%, 93.97%, and 92.60% at the machine speed of 260, 320, 380, and 440 mm/s, and the fruit tree damage rate was 1.67%, 1.78%, 1.92%, and 2.08%, respectively. The best comprehensive effect of weeding coverage rate and the highest operational efficiency was achieved at the operation speed of 380 mm/s. The average weeding operation coverage rate was 93.97% in the test, and the machine weeding operation coverage rate under the original obstacle avoidance control system was about 90.02%. The coverage rate of weeding operation increased by 4.39% at the same machine operation speed. Consequently, there was an excellent performance obstacle avoidance weeding in the highly precise control system of obstacle avoidance. This finding can provide a sound reference for further optimization of the interplant weeding machines in the modern orchards. [ABSTRACT FROM AUTHOR]

Cleaning components of cold-proof soil are still lacking for grape production in northern China. In this study, a novel arc impeller was designed to remove the cold-proof soil from the surface of grapes, particularly with low power consumption. Four components were divided, including the spline connection sleeve, impeller shaft, arc impeller blade, and connecting plate of impeller blades. A layered-staggered structure was adopted in the form of a cross arrangement. The external dimension of the arc soil cleaning impeller and the number of impeller blades were determined, according to the agronomic requirements of grape cold-proof soil cleaning in the study areas. Specifically, the rotary diameter and the height of the arc soil cleaning impeller were 600 mm and 300 mm, respectively, where there were two impeller blades in each layer. The main factors were determined on the power consumption under the movement and force of the arc soil cleaning impeller. The specific range of each factor was determined for the key experimental parameters, according to the actual operation. A three-factor quadratic regression orthogonal rotation center simulation was carried out using an extended distinct element method (EDEM), where the experimental factors were the forward speed, rotation speed, and bending angle of impeller blade in the soil cleaning impeller, whereas, the indicators were the torque and horizontal forward resistance. Design Expert 8.0.6 software was used to analyze the significance of the regression model on simulation experimental data. A regression model was established between the torque and horizontal forward resistance of the arc soil cleaning impeller and the experiment factors. The results showed that the primary and secondary order of experiment factors affecting the torque and horizontal forward resistance of soil cleaning impeller were the rotation speed, the forward speed, and the bending angle of the impeller blade. An optimal combination of operation parameters was achieved when taking the minimum torque and horizontal forward resistance of the arc soil cleaning impeller as the optimization target. Specifically, when the forward speed was 0.38 m/s, the rotation speed was 450 r/min, and the bending angle of the impeller blade was 18°, the torque and horizontal forward resistance reached the minimum of 9.99 N·m and 27.09 N, respectively. A soil bin verification experiment was carried out using the working parameters of optimization, where the optimized bending angle was processed in the soil cleaning impeller. Correspondingly, the torque and horizontal forward resistance of the arc soil cleaning impeller in soil bin verification experiment were 11.56 N·m and 31.82 N, respectively, while the relative errors between the simulated and experimental values were 13.58% and 14.86%, respectively. It infers that the soil bin verification experiment was basically consistent with the simulation. In any way, the torque and horizontal forward resistance were reduced by 9.40% and 15.37%, respectively, in the arc soil cleaning impeller, compared with the conventional straight-plate soil cleaning impeller. [ABSTRACT FROM AUTHOR]

Deep application of organic fertilizer in orchards was often confined to the excessive concentration of fertilizer, and low utilization rate in traditional agriculture. In this study, a feasible layered backfill device was designed for the mixed soil and fertilizer. An auger was used to transport the backfill soil and fertilizer. Paddles were arranged to evenly mix the soil and fertilizer. Three groups of mixed backfill components were set to realize the layered backfill. A theoretical calculation was conducted to determine the parameters of the backfill auger, according to the amount of backfill needed to be transported. Specifically, the outer diameter of the auger was 0.28 m, the pitch was 0.20 m, and the rotational speed was more than 98 r/min. Taking the sideward angle of paddle α, pitch angle of paddle β and rotational speed n as test factors, the relative standard deviation of organic fertilizer proportion and the average normal contact force of particle structure as evaluation indexes, a response surface simulation test was carried out to obtain the regression equation. An optimal combination of mixing paddle parameters was obtained, where the minimum evaluation index was taken as the objective. The best mixing effect was achieved, where the relative standard deviation was 40.35%, and the normal contact force was 0.33 N, when the sideward angle of paddle α, pitch angle of paddle β and rotational speed n were 90°, 60°, and 200 r/min, respectively. An attempt was also made to explore the influence of the length for the paddle arrangement area on particle mixing in the simulation test. The results showed that the uniformity of particle mixing increased with the increase in the length of the paddle arrangement area, which tended to be stable at 400 mm. The mixing paddles were arranged in the whole length of the front and middle mixing backfill parts, and only within the length of 400 mm for the post-mixing backfill part. A deflector was also designed for a better stratification effect. The reason was that the soil and fertilizer cannot be evenly distributed in the whole width range, even piled up directly in one place, particularly for the wide fertilizing ditch. A bench test was performed on the movement of particles at the discharging port, thereby evaluating the mixing performance of the device. When the optimal inclination angles of deflectors at the front, middle and back discharging port were 70°, 65°, and 50°, respectively, the soil and fertilizer in each layer was evenly distributed in the whole width of the fertilization ditch, indicating an improved stratification effect. A fertilizing ditch was opened with a width of 0.3 m, a depth of 0.4 m, and a length of 15 m. On the left side of the ditch, a ridge with a width of 0.2 m and a height of 0.2 m was set, on which the organic fertilizer was arranged. During the test, the feeding area was aligned with the ridge, and the discharging port was aligned with the ditch. After the test, three areas with a length of 0.5 m and width of 0.3 m were selected in the ditch, where 5-point sampling was used for sampling. The samples were laid flat in a box with a length of 280 mm and a width of 220 mm. Then the images were captured. An image processing was used to calculate the proportion of organic fertilizer. The relative standard deviation was 18.03%. In order to verify the accuracy of discrete element model and the reliability of the simulation optimization results, the sample size was set to be consistent with the bench test in the simulation test with the optimal paddle parameters, and the relative standard deviation of organic fertilizer proportion was calculated, which was 18.01%, the relative error was 0.11%. The results showed that the discrete element model was accurate, the simulation optimization result was reliable, and the mixing performance of the device was good, which can meet the requirements of soil fertilizer mixing operation. [ABSTRACT FROM AUTHOR]

Cold-proof mode has widely been updated for some vineyards in Xinjiang Region of northern China. The cold-proof cloth is normally used to assist in soil buried operation for better insulation of heat and moisture in complete soil clearing. However, the machine is still lacking for the soil clearing of winter grape and cold-proof cloth recycling, particularly in the early stage of popularization and application for the cold-proof cloth assisted soil-buried mode. It is also difficult to realize the smooth winding of cold-proof cloth. In this study, a new speed control system was proposed for smooth winding of grape cold-proof cloth in spring in Xinjiang Region, China. The linear velocity of the cloth roll was set to be equal to the forward speed of the machine. This system automatically detected the winding state of the cold-proof cloth. In smooth winding of the cold-proof cloth, the theoretical rotation rate of the DC motor was calculated in real time, according to the real-time changes of forward speed in a machine and the radius of cloth roller. A PID controller was adopted to control the duty ratio of Pulse Width Modulation (PWM) signal, then to adjust the rotation rate of the DC motor, further to drive the cloth roller for winding the cold-proof cloth. As such, the forward speed of the machine was used to realize the real-time adjustment of rotation rate for the cloth roller. At the time of cold-proof cloth deflected winding, the rotation rate of the cloth roller was adjusted to advance or lag the target rotation rate so that the cold-proof cloth was to restore the smooth winding state. Specifically, this study included the structure design of grape cold-proof cloth winding device, the hardware and software design of the control system. A control model was established in Simulink module using the motor transfer function model. In the simulation, the PID parameters were set, where the gain coefficients of proportion, integral, and differential were 0.3, 0.2, and 0.000 05, respectively. A physical prototype was also processed for the speed system. The static calibration test was carried out for the rotation rate of the DC motor, in order to obtain the relation between the motor rotation rate and duty ratio of the PWM signal. A performance test was conducted to verify the feasibility of automatic deflection adjustment for the cold-proof cloth. The optimized mounting distance of 20 mm was achieved for the laser switching sensor. PID parameters in the simulation test were taken as the intermediate levels in the performance experiment for the rotation rate of the DC motor, where each coefficient was tested at 4 levels in turn. The optimized proportion, integral, and differential gain coefficient were 0.3, 0.1, and 0.000 05, respectively, indicating basic consistency with the simulated values. The steady-state response time of the control system was about 0.4 s with a response delay of about 0.1 s, indicating a relatively small influence and good control effect. The performance test of slant winding cold-proof cloth was carried out, where the flatness was taken as the evaluation index. It was found that the flatness of the cold-proof cloth was more than 90% and the average was 92.78%, suitable for the operational requirements. The speed system with better control performance can provide a technical reference for the design and optimization of recycling machinery for the grape cold-proof cloth. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research 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.)

This paper presents the design of a device for crushing caked fertilizer for the deep applicator of organic fertilizer. It is a kind of toothed crushing blade. The process of designing this device combines the simulation test and the physical test. In the EDEM software, Hertz-Mindlin contact model and the bonding model were selected to establish the bonding model of the caked fertilizer crushing blade. To replicate the mechanical properties of the actual blade in the bonding model of the caked fertilizer crushing blade, a uniaxial compression test was carried out to calibrate the bonding parameters, and the regression equation of maximum force, displacement and bonding parameters of caked fertilizer were obtained. Aiming at the maximum force and displacement value obtained from the uniaxial compression physical test, the multi-objective genetic algorithm available in the optimization toolbox of MATLAB software was used to optimize the bonding parameter, and the optimal combination obtained was that the unit normal stiffness was 5.80×108 N/m3, the unishear stiffness was 3.50×108 N/m3, the critical normal stress was 3.29 MPa, the critical shear stress was 2.92 MPa, and the bonding radius was 1.26 mm. The simulation model of a single caked fertilizer crushing blade was established, through the single factor simulation test, the influences of the rotating speed, sliding cutting angle, edge angle, tooth width and tooth height of the crushing blade at the maximum value of three-way resistance, resultant force and the crushing rate of caked fertilizer were analyzed. Taking the ratio of the maximum resistance of the crushing blade to the crushing rate as the evaluation index, the uniform design simulation test was carried out. Regression analysis was carried out on the test data, and the regression equation between the evaluation index and the crushing blade parameters was obtained. The genetic algorithm in MATLAB software optimization toolbox was used to obtain the optimal combination of the crushing blade parameters. The optimal combination of the crushing blade parameters was that the rotating speed of the crushing blade was 300 r/min, the sliding cutting angle was 8°, the edge angle was 50°, the tooth width was 3.9 mm and the tooth height was 2 mm. The simulation verification test was carried out based on the optimization results. The results showed that the maximum resistance to the blade was 74.59 N, the crushing rate was 25.63%, and the ratio of the maximum resistance of the crushing blade to the crushing rate was 291.03 N. According to the optimized results, the fertilizer crushing blade was processed, and the physical test was carried out on the fertilizer crushing device powered by BMM-50 hydraulic motor. At the same time, the oil inlet pressure of the motor was measured by the oil pressure sensor to evaluate the energy consumption. After crushing, the particle size distribution was determined to evaluate the crushing quality. The results showed that the average oil pressure for crushing was less than 2.44 MPa, and the average energy consumption required for crushing was less than 480 W, the particle size of the fertilizer was less than 20 mm. The blade has low energy consumption and high crushing rate and can be used for the caked fertilizer crushing operation. [ABSTRACT FROM AUTHOR]

Aiming at the problems of grapevine cold-proof cleaning in sandy loam soil areas of northern China in spring, such as, the degree of mechanization is low, the soil is not clean thoroughly, and the grape trees are easy to be damaged, this paper proposed a cold-proof soil cleaning parts with flexible brushes and rubber, and designed an automatic obstacle-avoiding grapevine cold-proof soil cleaner based on the coupled simulation method of multi-body dynamics software RecurDyn and discrete element software EDEM. The machine was mainly composed of frame, obstacle-avoiding swing mechanism, obstacle-avoiding signal acquisition mechanism, controller, soil cleaning parts, soil retaining plate, transmission mechanism and depth wheel. The structural parameters of the key components were determined based on the analysis of the working principle of the machine. The stroke of the obstacle-avoiding cylinder was 200 mm, the obstacle-avoiding cylinder bore was 40 mm, and the turning diameter of the soil cleaning parts was 550 mm. In order to reduce the amount of simulation calculations and improve simulation efficiency, the model was simplified and imported into the multi-body dynamics software RecurDyn. Using the discrete element software EDEM to model the soil particles and a ridge with an isosceles trapezoidal cross section was obtained. Based on coupling simulation tests of RecurDyn and EDEM, the automatic obstacle-avoiding process and the soil cleaning effects of the machine were simulated. The operating parameters of the machine were set in RecurDyn software, and the process and effect of soil cleaning were simulated in EDEM software. Taking the forward speed of the machine, the velocity of the obstacle-avoiding cylinder, the rotation speed of the soil cleaning parts and the threshold value of rotation angle of the touch rod as the test factors, the soil cleaning rate was the test index, the four-factor quadratic regression orthogonal rotation center combination simulation test were carried out. Design-Expert software was used to analyze the regression significance of the test data. The results showed that the four test factors all had a significant effect on the test index. Among the interaction factors, only the rotation speed of the soil cleaning parts and the threshold value of the rotation angle of the touch rod had a significant impact on the soil cleaning rate, while the other interaction factors had no significant impact. Among the quadratic factors, the square of velocity of obstacle-avoiding cylinder had a significant effect on soil cleaning rate, while the rest factors had no significant effect. Taking the maximum soil cleaning rate as the optimization goal, the optimal operating parameters of the machine was obtained: the forward speed of the machine was 0.43 m/s, the velocity of the obstacle-avoiding cylinder was 60 mm/s, the rotation speed of the soil cleaning parts was 550 r/min, and the threshold value of the rotation angle of the touch rod was 10 °, at this time, the theoretical soil cleaning rate was 54.65%. Based on the optimization result, the physical prototype was processed. Using the iron tubes inserted into the soil to simulate the concrete column, cold-proof soil ridges similar to that in the vineyard were generated by grapevine soil burying machine, the soil cleaning tests were carried out. The test results showed that the average value of the soil cleaning rate was 59.73%, the relative error between the test result and the simulation optimization result was 8.50%, the operation effects meet the requirements of automatic obstacle-avoiding grapevine cold-proof soil cleaning. The research results can provide theoretical basis and technical support for the overall design and optimization of obstacle-avoiding mechanism of earth-touching machines and tools. [ABSTRACT FROM AUTHOR]

In Xinjiang region of China, the grape cultivation area needs to take soil buried cold-proof operation in winter to make the vines safely overwinter. However, the single soil buried cold-proof operation brings great difficulties to the subsequent soil clearing operations, such as incomplete soil mechanical clearing and low operation efficiency. The vineyards headed by Xinjiang change the cold-proof mode, and the cold-proof cloth is used to assist in soil buried cold-proof operation, which can play a better effect of heat preservation and moisture conservation and provide the possibility for complete soil clearing. But at the same time, there are some problems such as difficulty in recycling cold-proof cloth. In view of the problems in the above-mentioned soil clearing operation and the agricultural requirements of the trellis-type grape planting, combined with the operation requirements of the grape soil clearing under the cold-proof cloth assisted soil-buried mode, this paper designed the grape winter buried soil clearing and cold-proof cloth recycling machine, which is composed of a frame, a soil clearing component, a cloth recycling component and a hydraulic system, etc. This paper explained the structure and working principle of each part of the machine in detail, and analyzed the structure and parameters of key components. The tensile performance test of the cold-proof cloth used for one year was carried out to verify the feasibility of the cold-proof cloth recycling. The result showed that the tensile strength of the old cold-proof cloth was lower than that of the new cold-proof cloth, and the warp tensile strength was better than the across, but it was not enough to affect its recycling, based on this the correct direction of the cold-proof cloth using was determined, and the basis for the design of cloth recycling component was provided. Discrete element software EDEM was used to carry out simulation test of soil clearing operation. The simulation model consisted of soil ridge and soil clearing component modes in EDEM software. The soil clearing distance was used as the evaluation index of soil clearing effect, and the experimental factors were the curvature radius of the working face of the scraper, the blade numbers of the soil clearing impeller and its rotation rate. Under the condition of 2 km/h, the three-factor five-level simulation orthogonal test was carried out. The results showed that the order of influence of three factors on soil cleaning distance was that curvature radius, blade number and rotation rate. According to the variance analysis of test result, the curvature radius was the significant influencing factor, the blade number and rotation rate were the non-influencing factors, and the optimal parameter combination was that the curvature radius was 680 mm, the blade number was 4, the rotation rate was 500 r/min, and the clearing distance was 294.27 mm. The prototype was processed and the field verification test was carried out based on the optimal parameter combination. The test results showed that the soil clearing distance was 271 mm, and the relative error with the simulation test results was 8%. The buried soil was basically cleaned and the damage to the vines and the cold-proof cloth was small. The operation efficiency of the machine was more than 10 times of the manual soil clearing efficiency. This study can provide a new development idea for the operation of buried soil clearing in Xinjiang regions of China, and provide reference for the development of follow-up grape soil clearing machinery. [ABSTRACT FROM AUTHOR]

Grapevine in seasonally frozen regions needs to be warm-insulated by soil in winter with the antifreezing soil removed in spring most mechanically by a soil removal machine. The purpose of this paper is to simulate the interaction between the insulating soil (with sandy loam texture) and the soil-cleaning materials (Q235 steel, rubber) commonly used in the soil removal machine, based on the discrete element method. The simulation model was constructed based on properties of the soil by integrating the hysteretic spring contact model (HSCM) and the linear cohesion model (LCM) as the contact model between soil particles. We took soil-soil restitution coefficient, soil-soil frictional coefficient, soil-soil rolling coefficient and soil cohesion energy density as the determinants and the soil accumulation angle as an evaluation index. The 4-factor universal rotation center combination simulation test, based on the EDEM, was used to regress the relationship between the determinants and the index using the Design-Expert software. The results showed that the soil-soil frictional coefficient was the only parameter that did not have significant effects on the soil accumulation angle. The best contact-parameter combination between soil particles was obtained by taking the physically measured soil accumulation angle as the optimization objective, which gave 0.51 for the soil-soil restitution coefficient, 0.65 for the soil-soil frictional coefficient, 0.06 for the soil-soil rolling frictional coefficient, and 10 495 J/m³ for the soil cohesion energy density. The associated soil accumulation angle was 31.74°, with a relative error of 0.83% compared with the physically measured results. The universal testing machine for soil yield test was used to obtain the HSCM model parameters based on the change in penetration stress with the displacement, and the resultant soil yield strength was 0.38 MPa. The static frictional coefficient between soil and Q235 steel as well as the rubber measured by the inclination test bench was 0.38 and 0.48 respectively. These data and the EDEM were used to conduct the simulation test of the soil slip, with the restitution coefficient and the rolling frictional coefficient between soil and the materials taken as the determinants and the sliding frictional angle as evaluating index. Regressing the test date with the two-factor universal rotation center combination test showed that the rolling frictional coefficient between soil and the materials had a significant effect on the sliding frictional angle between soil and the steel plate and rubber. In contrast, the restitution coefficient between the soil and the materials impacted significantly on the sliding frictional angle between the soil and the rubber but not on the soil and the steel plate. The restitution coefficient and the rolling frictional coefficient between the soil and the Q235 steel as well as the rubber were optimized by using the measured sliding frictional angle as the optimization objective. The resultant restitution coefficient and the rolling frictional coefficient were 0.60 and 0.37 respectively for the soil and the Q235 steel, and 0.61 and 0.23 respectively for the soil and the rubber. Soil bin test and simulation test of the scraper were conducted to verify the calibrated discrete element model parameters. The horizontal forward resistance of the scraper in the soil bin test and simulation test was 228.36 and 213.79 N respectively, with a relative error of 6.38%. The results presented in this paper have important implications for using discrete element method to analyze the removal of grapevine-insulating soil. [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.)

Considering the problems of low efficiency and large area without weeding around the vine after operation, a bilateral operation intra-row auto obstacle avoidance weeder for trellis cultivated grape was designed. The weeder consisted of frame, hydraulic system, transmission system, land wheel and weeding device. Frame was installation carrier for all of machine components. Hydraulic system was used to provide power for weeder, driving two hydraulic motors and four hydraulic cylinders. Transmission system was the medium which transmitted power from tractor to hydraulic system. Land wheel made it possible to adjust the weeding depth. Weeding device was the key component for the weeder, and it was composed of row width adjustment mechanism, signal acquisition mechanism, auto obstacle avoidance mechanism and weeding cutter head. The extending distance of row width adjustment mechanism could be adjusted from 0 to 400 mm to adapt different row spacings in different fileds. The specific location of the grape vine could be identified correctly with signal acquisition mechanism. And the obstacle avoidance mechanism could avoid weeding cutter head from contacting the grape vine, which probably caused injuries. The weed was destroyed under high-speed rotation of weeding cutter head driven by hydraulic motor. The parameters of these key components of weeding monomer were determined by theoretical analysis and experiment. In order to research the effects of structural and operation parameters of automatic obstacle avoidance weeder, a brief virtual prototype model was built in ADAMS software, and key components were parameterized simultaneously. To simplify calculation, using link mechanism to replace the complex machine and constraints were set between different links. Kinematics simulations was carried out using virtual prototype model, and the simulation results of operating trajectory of weeding cutter head agreed with theoretical analysis. Then single factor simulation experiments were carried out in ADAMS with the coverage rate of weeding selected as the evaluation index. The simulation results confirmed that speed of obstacle avoidance hydraulic cylinder, operating speed of the weeder and angle threshold (defined as the rotation angle of feeler lever when control system triggered the automatic obstacle avoidance mechanism) were the main influence factors. Operating speed and angle threshold had positive impact on it, while speed of obstacle avoidance hydraulic cylinder had negative impact on it. In addition, quadratic regression general combination experiments were conducted by taking speed of obstacle avoidance hydraulic cylinder, operating speed and angle threshold as the experiment factors and coverage rate of weeding as the evaluation index. Analysis of variance (ANOVA) was performed to find the statistically significant parameters in field experiments and quadratic regression model was set up by response surface methodology with Design-Expert 8.0.6. It was showed that speed of obstacle avoidance hydraulic cylinder, operating speed and angle threshold were extremely significantly (P<0.01) effective parameters, and the interaction of speed of obstacle avoidance hydraulic cylinder speed, operating speed and angle threshold were significantly (P<0.05) effective on coverage rate of weeding. Furthermore, the optimizing function of Design-Expert 8.0.6 was used for the optimization in this paper and the results showed that when speed of obstacle avoidance hydraulic cylinder was 160 mm/s, operating speed was 380 mm/s and angle threshold was 15.12°, the optimal average coverage rate of weeding was 90.15%. Field experiment with the optimal combination of key parameters were carried out to testify the validity of optimization. The coverage rate of weeding was 90.02%, which is 0.67 percentage points higher than the results of quadratic regression general combination tests. This study could provide a reference for further research of intra-row weeder for trellis cultivated grape and other plants. [ABSTRACT FROM AUTHOR]

Automatic directional packaging of corn seeds is the precondition for realizing mechanical directional sowing of corn. The key technology is tip orientation and embryo side facing recognition. Combined with the actual demand of directional packaging, tip orientation for dent corn seeds needs that the tip orientation success rate reaches 100% (i.e. the tip is completely directed), and the embryo side facing recognition accuracy rate is required to achieve a high level at the same time. In addition, combining the actual demand of agricultural production and popularization, the method and its dependent device used to realize the tip orientation and embryo side recognition method for corn seeds should have low requirements for the working environment and the operation cost should be reduced as far as possible. The existing methods of tip orientation and embryo recognition are difficult to fulfil practical requirement. On the basis of the available research results of the research team, taking dent corn seeds with horizontal posture and tip orientation incomplete exported by existing tip orientation device as research object, a tip orientation and embryo side recognition method for dent corn seeds based on laser switch and range theory was proposed and the tip orientation and embryo side recognition device was designed in this paper. According to the shape characteristics of the corn seeds, the corn seeds large head facing forward was removed by using the laser sensors and other components first to get the seeds tip orientation done, and then the embryo side facing direction of each corn seed was identified one by one and outputed. There were 2 main characteristics of the corn seed shape: shape characteristic and surface characteristic. The shape characteristic was that the outline of corn seed was similar to "V" shape with narrow tip and wide large head, the surface characteristic was that there was a germinal groove extending from tip to large head on the embryo side, and the germinal groove shape was approximately elliptical, and its long axis coincided with the symmetric axis of the embryo side, the reverse side was smooth. The tip orientation method was proposed based on the shape characteristics of corn seed and laser switch sensor. Referring to the shape characteristics of the corn seed, a "V" shape slot was designed, the corn seeds with tip facing forward could enter into the slot, while the corn seeds with large head facing forward could not enter the slot as the large head of seed would block the entrance, based on this difference, by means of a normally open laser switch sensor, a specific straight track and a push rod, the tip orientation of each corn seed could be identified and the corn seeds with large head facing forward were removed. When the seed’s tip was oriented, it would be stayed in the slot with tip facing forward, and then the direction of embryo side would be recognized based on the surface characteristic and laser range sensor. With the combined of designed device and existing tip orientation device, a practical test bench was built and the orientation test for dent corn seeds was carried out to verify the actual effect of tip orientation and embryo side recognition method. The result showed that: the tip orientation success rate of existing tip orientation device was 89.6%, the embryo side recognition accuracy rate of designed device was 96.4% and the tip orientation success rate of designed device was 99.1%, which increased by 9.5 percentage points comparing with the existing tip oriented devices. The orientation method proposed in this study could basically realize the tip orientation of the corn seeds, and at the same time, the embryo side recognition accuracy rate could be reached to a high level. Generally, the tip orientation and embryo side recognition method and the device proposed in this paper have low requirements for working environment and low operation cost, which could provide a reference for automatic directional packaging and mechanically directional sowing of corn. [ABSTRACT FROM AUTHOR]

As the parameters of discrete element model for organic fertilizer are difficult to obtain directly from literatures or experiments, this study proposed a method to calibrate the parameters based on tests of the angle of repose. Firstly, a physical test was carried out. The diameters of organic fertilizer particles were between 0.25 and 2 mm, the fertilizer moisture was 13.7%, and the organic fertilizer was crushed to meet the requirements of uniformity of fertilization. In the test, in order to obtain the organic fertilizer heap, the cylinder was lifted up by a universal testing instrument at a speed of 20 mm/s. Then, the angle of repose of the fertilizer was measured with inclinometer and the test was repeated for 10 times, as the mean angle of repose was 38.15°. Secondly, the simulation test was carried out. Considering the cohesion characteristics between particles of organic fertilizer, the contact model of Hertz-Mindlin with Johnson-Kendall-Roberts was used in simulation modeling. Since the organic fertilizer particles were near-spherical, the basic model of the software default was adopted to simulate organic fertilizer granules. In the simulation test, the relative error was 2.22% by comparing the angle of repose formed by a variety of particle sizes according to actual particle size distribution and the angle of repose formed by the same particle size (1 mm). Therefore, a basic sphere model with a radius of 1 mm was used and the three-dimension geometry model built by SolidWorks was imported into the simulation software, with the cylinder lifting speed was 20 mm/s, the total number of particles was 10 000, the generation rate was 2 000/s, the fixed time step was 22% of Rayleigh time step, the target save interval was 0.01 s, and the cell size was 2 mm. Not all discrete element model parameters of organic fertilizer had significant impact on the angle of repose, so a screening through Plackett-Burman Design was made. The results showed that rolling friction coefficient between organic fertilizer, surface energy (JKR) and rolling friction coefficient between organic fertilizer and steel plate had significant impact on angle of repose. The optimal value interval of the there significant parameters was determined by the steepest ascent test, and built the linear regression model of angle of repose through Central Composite Design. The fitting of the linear regression model was optimized by adding the quadratic term and cubic term of rolling friction coefficient between organic fertilizer with the fitting of the regression model had a great improvement, and the P value of the lack of fit was improved from 0.091 to 0.405 6. Thirdly, the optimal value of the significant parameters was obtained with the actual angle of repose as a goal, with the rolling friction coefficient between organic fertilizer was 0.10, the JKR was 0.015, and the rolling friction coefficient between organic fertilizer and steel plate was 0.11. Finally, in order to verify the accuracy of the calibrated parameters, the simulation verification test of the calibration parameters was carried out, and the relative error between the simulated angle of repose and the actual angle of repose is 0.42%, which meant that the calibration parameters were accurate. This study can provide reference for the selection of discrete element model parameters of organic fertilizer. [ABSTRACT FROM AUTHOR]

The method of regarding corn seed as bullet to sow is a new way, which can realize mechanically directional sowing of corn. The concrete realization process is as follows: Firstly, it needs to make directional corn seed bullet clip, and then the corn seed in the bullet clip is inserted into the soil by specific equipment. The key technology of making directional corn seed bullet clip is directionally pushing corn seeds. In order to realize directionally the pushing of corn seeds, taking dent corn seeds with horizontal posture as research object, most tip orientation of which had been oriented by existing directional device, in this paper, a directional push device for dent corn seeds was designed. Those dent corn seeds could be directionally received, then directionally moved and pushed by the device. The device consisted of 3 parts: directional receiving and moving mechanism, directional pushing mechanism, and power unit. Among them, the directional receiving and moving mechanism was mainly composed of a turntable, 4 seed holders, a turntable base and other components. The directional pushing mechanism mainly consisted of a cam, a linear push rod and some others. And the power unit was a simple stepper motor system. There were 2 kinds of stations when corn seeds with horizontal posture got into the seed notch on seed holder: tip facing forward or main part facing forward. The working process of directional push device for corn seeds was as follows: The turntable started to rotate after corn seeds got into the seed notch, taking seed holders and corn seeds turning together on the turntable base. The corn seeds with main part facing forward would be eliminated when the seed holder passed through the sorting notch, and the corn seeds with tip facing forward could be passed through smoothly, thus completing the directional receiving of the corn seeds. The turntable continued to rotate, and the corn seeds held were kept relatively fixed with the seed holder under the constraint of guard board, and the turntable stopped after turning 90°, thus completing the directional moving of the corn seeds. At last, the linear push rod would push each seed in seed holder outward to complete the directional pushing function. Among the 3 functions of the directional push device for corn seeds, the directional receiving function was the most critical, as it provided a basis for directionally moving and pushing. The analysis of the principle of directional receiving function showed that the shape parameters of the sorting notch had great influence on the process of directionally receiving. Taking arc angle and depth of sorting notch as factors, and respectively taking holding success rate of corn seeds with tip facing forward and elimination success rate of corn seeds with main part facing forward as test index, 2 simulation tests were carried out with corn seeds of 2 different stations. The best parameters of the sorting notch were obtained: Arc angle was 14° and the depth was 3 mm. Under this condition, the holding success rate and elimination success rate respectively reached 94% and 100%. In order to verify the accuracy and reliability of simulation optimization result and test the performance of the device, the practical directional push device for corn seeds was constructed. A performance experiment was performed with 600 corn seeds whose most tip orientation had been oriented. The results show that the device works stably, and the 3 functions of directional receiving, moving and pushing perform well. For directional receiving function, the holding success rate of corn seeds with tip facing forward and elimination success rate of corn seeds with main part facing forward are respectively 93.8% and 100%, which coincide with simulation very well. Generally, this research provides a reference for mechanically making directional corn seed bullet clip subsequently and mechanically directional sowing of corn. [ABSTRACT FROM AUTHOR]

Navel orange is rich in nutritive value and has high edible and medicinal value, and it is loved by people. With the increase of planting area and yield of navel orange, Gannan navel orange industry has developed into an industry cluster which integrates production, logistics and deep processing. Also, mechanical and intelligent picking is an inevitable trend in modern agriculture. The picking robot is one of the important equipment of intelligent agriculture, which plays an important role in promoting the agricultural transformation and upgrading. As one of the most important parts of the picking robot, the end effector, has a direct influence on the success rate, damage rate and the work efficiency of the picking operation. In order to improve mechanical and automatic picking level, meet the requirements of non-destructive picking for navel orange and solve the shortage of labor force, a new picking end-effector was designed. It mainly consisted of 3 parts, i.e. adsorption mechanism, clamping mechanism and rotary cutting mechanism. The fruit could be quickly separated from the fruit cluster by the adsorption mechanism, and stably and non-destructively clamped by the clamping mechanism, and the rotary cutting mechanism mainly realized the separation of the fruit and the fruit stalk. At the same time, the mathematical model of navel orange was established by fruit index test, which was a standard ellipsoid. The mechanism model was established on the basis of the navel orange equatorial plane and with the horizontal diameter as the index. Each joint was designed to V type and the transverse diameter range of navel orange harvested was determined as 50-100 mm. In order to ensure the finger surface and recoverable diameter range of arbitrary navel orange have 4 tangent points in holding and the 4 sensors can feed back pressure value in real time, the parameters of the finger were simulated and optimized by CAD, finally obtaining the ideal parameters. The minimum positive pressure was determined by the static stress analysis of navel orange to 0.77 N. In the compression experiments of the equatorial surface of navel orange with different diameters at the different speeds of loading, which were 100 and 200 mm/min, the maximum deformation was determined as 5 mm and the maximum positive pressure was 25.57 N. In the friction coefficient experiment with 3 common materials which were rubber, foam and silica gel, the silica gel was chosen as buffer material and the coefficient of friction was 1.275 by comparing the results of repeated tests of each material. Through the analysis of a series of experiments above, a finger feedback system with a resistive thin-film pressure sensor was designed and a rationally designed drive motor was used to achieve stable and non-destructive picking requirements. What was more, hardware and software of the control system of end effector were designed. Hardware system mainly contained electric relay, stepper motor, motor drivers, force sensor, I/O (input/output) board, solenoid valve and embedded motion controller. Main-computer control interface was designed by MFC (microsoft foundation classes) frame. MFC frame is always used in VC++ software. Program of submitted computer was designed in Language C. Through the above design, the highly integrated hardware that could be controlled by visual software was realized. Lastly, the reliability of end effector for picking navel orange was examined though experiments after the whole platform was established. In the experiments, different stepper motor speeds were took as the influencing factors, and the picking time of single fruit, the picking success rate and the damage rate as the indices, and the experiments were carried out 105 times. The test results show that the average picking success rate is 94.28% when the speed of the stepper motor is 250 r/min, the picking time of single fruit is 1.76 s, and the fruit damage rate is 0. The end effector is proved to be useful and reliable, and provides reference for research on the development of key components of the late navel orange robotic picking. [ABSTRACT FROM AUTHOR]

Wolfberry belongs to Solanaceae, Lycium. Studies have shown that the LBP has many effects, such as delaying aging, anti-tumor, anti-fatigue, controlling blood sugar, preventing glaucoma and so on. The main producing areas of wolfberry are Ningxia, Inner Mongolia, Xinjiang, Hebei, Qinghai, Hubei and Tibet. In recent years, wolfberry acreage increased by 11% annually. Wolfberry is infinite inflorescence, and the end of June to early October is the picking period of wolfberry. Wolfberry is in continuous flowering during the picking period, and the average picking cycle is 7 days. Wolfberry picking is still dependent on artificial, so low efficiency and high labor cost are the most prominent issues. The efficiency of artificial picking wolfberry is only 3 ~ 5 kg/h, while the cost is up to 34 500 yuan / hm2, accounting for more than 50% of production costs. With the growing area of wolfberry, the labor force will be in short supply, so the picking problem has become the bottleneck restricting the sustainable development of wolfberry industry. Wolfberry is less cultivated abroad, so there are few researches on large-scale cultivation and mechanized picking of wolfberry in foreign countries. The domestic research on wolfberry picking machinery began in the early 21st century and was carried out mainly in several major producing areas. At present, according to the different principles of picking, wolfberry picking machinery can be divided into 4 main types: shear, brush comb, vibration and air flow. However, the current various picking machinery has obvious defects. This study designs a vibrating wolfberry harvesting device with comb brush bases on combing vibration method and tests it. The device consists of harvesting unit and lifting mobile unit. Harvesting unit includes: comb brush vibration mechanism, DC motor, timing pulley, support frame, baffle. Among them, the comb brush vibration mechanism is the key component, which including left input shaft, right input shaft, harvesting rob, T reducer, disc, connecting rob, coupling, slider and sliding shell. The 4 rows of harvesting poles and the shell are fixed by bolts. The shell and the slide are also fixed by bolts. The slide block and the slider are matched with each other so as to make linear motion along the slider. The 2 ends of the connecting rod are respectively hinged with the shell and the disc. Harvesting unit is used to achieve the recovery of wolfberry fruit. Lifting mobile unit is a hydraulic lift trolley. The harvesting unit is fixed on the lifting mobile unit, and the whole harvesting device can move horizontally and vertically. Based on ADAMS software, the model of Lycium barbarum fruit and branch, the model of comb vibration are established by parameterized modeling. The connecting force between fruit and fruit stem is connected by generalized force. The sensor is used to monitor the fruit stem breakage condition, which realizes the process control of separation of fruit and stem of wolfberry. Through the simulation analysis, it is determined that the brushing speed, the disc speed (vibration frequency) and the vibration amplitude of the harvesting device have a significant effect on shedding of wolfberry fruit. The field experiment is carried out to evaluate the harvest efficiency, the harvest rate of mature wolfberry, the shedding rate of immature and the damage rate of mature wolfberry. Test results showed that the best combination was that the comb brush speed is 80 r/min, disc rotation speed is 100 r/min, vibration amplitude is 80 mm. Based on the combination of the factor level, the harvest efficiency is 13.12 kg/h, the harvest rate of mature wolfberry is 87.46%, the shedding rate of immature is 13.81%, the damage rate of mature wolfberry is 2.82%. Compared with other single-principle harvest mechanisms, the device not only achieves harvest efficiency and higher mature harvest rate, but also guarantees relatively low shedding rate of immature and damage rate of mature wolfberry. This studdy can provide theoretical basis and data support for the design of the mechanized harvesting machinery of wolfberry. [ABSTRACT FROM AUTHOR]

At present, in the trellis vineyard, the methods of mechanical weeding are mainly divided into inter-row mechanical weeding and intra-row mechanical weeding. The development of intra-row mechanical weeding is relatively slow, because the identification and location for crop and weed is difficult in the process of mechanical weeding. Now, the theoretical study on intra-row mechanical weeding of trellis cultivated grape is not very much. In order to achieve the intra-row weeding of trellis cultivated grape, this paper designs an auto obstacle avoidance mechanism based on the existing weeder, which includes parallel four-bar linkage mechanism and trigger mechanism of obstacle avoidance. The contact rod is composed by 2 straight lines and an arc connecting straight lines in the trigger mechanism of obstacle avoidance. And the theoretical working principle of auto obstacle avoidance mechanism is described. After the pre-test, it is found that the length of the straight section of the first section of the rod, the arc angle of the intermediate transition arc and the 3 distances between the contact rod and the edge of the weeding part have obvious effect on the result of weeding. So a virtual prototype model for auto obstacle avoidance mechanism is built in ADAMS, and the trigger mechanism of obstacle avoidance is parameterized. Then, the orthogonal test is conducted by taking the combination of 3 distances between contact rod and edge of weeding part and the length of the first part of the rod as the test factors and the area which is not covered by the weeding parts after the work as the experimental index. The results show that the combination of 3 distances and its interaction with the arc angle of intermediate transition are significant factors. In order to analyze the effect of the combination of 3 distances on the area not covered by the weeding parts after the work deeply, the length of the first part of the rod is set as 1050 mm, the arc angle of intermediate transition is 85°the forward speed is 390 mm/s, the initial velocity of the cylinder is 50 mm/s, and furtherly taking the parameter the combination of 3 distances as the test factor and the area not covered by weeding parts after the work as the experimental index, the optimization simulation is conducted. The results show that the optimal value is obtained when the 3 distances between contact rod and edge of weeding part are 225, 300, and 212 mm, respectively. The area not covered is 783 mm2except the scheduled area which is not needed to weed. It is very small, so the weeds can be considered to be removed completely, which shows the result of weeding is good. On the basis of simulation optimization, the field tests of single obstacle avoidance and continuous obstacle avoidance are also carried out, in which the combination of 3 structural parameters of the obstacle avoidance mechanism is set as variable and the parameters such as length of the first part of the rod and arc angle of the intermediate transition arc as constant values. The field test results show that the average coverage rate of weeding operation after optimization is 97.5%, which is about 8% higher than before, and the standard deviation is 2.98%, which is lower than before. The stability of weeding is also better, and the effect of optimization is obvious. Generally, this study enriches the method of identification and location for crops and weeds in the process of mechanical weeding, and also provides reference for the improvement of the design of intra-row weeder for trellis cultivated grape. [ABSTRACT FROM AUTHOR]

The electromagnetic vibration hopper can be used to disperse and transport corn seeds in order. However, presently, there are few studies on the mechanism of dispersion and arraying transport of corn seeds under circular electromagnetic vibration, and limited parameter optimization for electromagnetic vibration hopper, which result in unreliable effects and efficiency of stacked corn seeds' dispersion and arraying transport. In order to solve the problem, firstly, the theoretical study on the mechanism of stacked corn seeds' dispersion and arraying transport in electromagnetic vibration hopper was done, from which the regulations were summarized and the influential factors were concluded as inclination angle of bottom, orbit pitch and working voltage. Then a simulation model was established by EDEM (enhanced discrete element method), adopting 200 corn seeds and a hopper. Meanwhile 2 parameterized sinusoidal motion functions were respectively applied in vertical direction and circle direction for the hopper to enable its vibration effect consistent with the actual electromagnetic vibration hopper. In the simulation test, dispersion time and total time were test indices, while inclination angle of bottom, orbit pitch and working voltage were influence factors. By observing the motion state and motion trajectory of stacked corn seeds in the hopper and analyzing the relationship between influence factors and test indices, the theoretical study results were verified and supplemented. At the same time, the electromagnetic vibration hopper was optimized. Lastly, the orthogonal test was conducted based on actual corn seeds and electromagnetic vibration hopper to verify the rationality of simulation optimization results, and the total time was taken as test index, and the inclination angle of bottom, orbit pitch and working voltage as influence factors as previous simulation test. Consequently the following results were gained: 1) The dispersion motion of stacked corn seeds was a compound motion, including forward circular motion, centrifugal motion and sliding motion. In the heap of corn seeds, the higher position of one corn seed resulted in smaller movement speed; the larger radius resulted in faster movement. 2) When the hopper diameter and height were determined, there were 3 factors related to the motion state of stacked corn seeds' dispersion and arraying transport, namely inclination angle of bottom, orbit pitch and working voltage. Among them, the inclination angle of bottom mainly influenced the dispersion motion; the orbit pitch only affected the arraying transport motion; the working voltage had effect on both of the 2 motions. Specifically, with the inclination angle of bottom increasing, the efficiency of stacked corn seeds' dispersion was improved, whereas the total efficiency barely changed. If the orbit pitch was less than 35 mm, its increasing would improve the total efficiency, but further increasing would reduce the total efficiency. If the voltage was less than 220 V, its increasing would significantly enhance the total efficiency, but further increasing showed no benefit to the total efficiency, and on the other hand resulted in unstable motion state. 3) The optimized working voltage was 220 V, the inclination angle of bottom was 4°, and the orbit pitch was 35 mm. Under these conditions, the stacked corn seeds' dispersion and arraying transport were stable with a high total efficiency. Generally, this research enriches the mechanism of stacked corn seeds' dispersion and arraying transport under circular electromagnetic vibration, and also provides reference for directional packaging and directional sowing of corns. [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.)

At present, the theory of the motion of the material under the electromagnetic vibration is still not perfect, which results in the lack of theoretical guidance for the optimization of the directional arrangement device of corn seeds based on circular electromagnetic vibration. To solve this problem, the theoretical research on the movement characteristics of single corn seed under the circular electromagnetic vibration was carried out in cylindrical coordinate system, and the working angle amplitude, the occupied circle radius of corn seed and the angular velocity of corn seed’s forward circular motion were taken as the main parameters in this paper. And the theoretical research consisted of 2 main parts: relative motion theory and self motion theory. Then, the practical experiments on single corn seed were carried out under 2 conditions of embryo face up and down. The practical experiments included 3 parts: the relative motion characteristics test, the self motion characteristics test and the forward circular motion characteristics test. The state changes of relative motion, self motion and the size changes of the angular velocity of corn seed’s forward circular motion were observed under different working angle amplitude and occupied circle radius of corn seed in each test. The theoretical analysis could be verified and supplemented by the practical experiments. The following results were gained: 1) The relative motion characteristics of single corn seed showed that under the electromagnetic vibration there were 4 primary movement states: forward circular motion, reverse circular motion, throwing motion and centrifugal motion, and there were also 4 critical angle amplitudes respectively corresponding to the states. It meant that when the working angle amplitude of circular electromagnetic vibrator reached each critical angle amplitude, the single corn seed would carry out the corresponding movement. The effect of the embryo’s direction of single corn seed on 4 critical angle amplitudes was very small. The critical angle amplitude corresponding to throwing motion was always kept to equal to 0.012 9 rad, but the other 3 critical angle amplitudes were related to the occupied circle radius of corn seed, and the relationship was that they would decrease with the occupied circle radius of corn seed increasing. Besides, the critical angle amplitude corresponding to throwing motion was larger than that corresponding to reverse circular motion and then that corresponding to forward circular motion at all time. 2) As the self motion characteristics of single corn seed revealed, the embryo’s direction of single corn seed had obvious influence on self motion law of corn seed. The law was that corn seed could adjust its tip orientation concordant with the tangent line of the circular movement by self reverse or forward rotation when its embryo faced up, but the tip orientation of corn seed would be random without a clear law when its embryo faced down. 3) As the forward circular motion velocity characteristics of single corn seed revealed, when the embryo faced up, the angular velocity of corn seed’s forward circular motion was always larger than that when the embryo faced down before the amplitude of circular electromagnetic vibrator reached 0.008 rad; the angular velocity of corn seed’s forward circular motion could increase with the increase of the angle amplitude, and after 0.008 rad it could decrease regardless of the embryo’s direction. The best working angle amplitude of circular electromagnetic vibrator was 0.008 rad, and under this condition, the angular velocity of corn seed’s forward circular motion could reach the maximum (4.15 °/s when the embryo of corn seed faced up and 4.03 °/s when the embryo of corn seed faced down). This research enriches the movement theory of materiel under the circular electromagnetic vibration, and provides the theoretical reference to the optimization of directional arrangement device for corn seeds. [ABSTRACT FROM AUTHOR]