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Cotton, one of the main commercial crops in the world, mostly distributes in several major growing regions, including Xinjiang of western China. An important renewable biomass resource, the cotton stalk has received most attention to serving as the poultry feed, paper making, environmental protection materials, and biomass briquette fuel. Particularly, the highly efficient recycling of cotton stalk can be widely expected to bring enormous economic and ecological benefits. However, most previous treatments are focused on pulverizing cotton stalks and returning to the field. A great challenge is still posed on the current pulling machines for cotton stalks, with emphasis on operational requirements, leakage, and breaking rate. In this study, a novel horizontal-roller cotton stalk pulling machine was proposed to efficiently implement the pulling of the whole cotton stalk after harvesting. The machine was mainly composed of traction, gearbox, stalk conveying, transmission system, machine body, road wheel, spacing regulating mechanism, stalk pulling, dam-board, and support frame. Specifically, the power input shaft of the gearbox was connected to the power output shaft of a tractor. In working, the power was transferred to the chain drive by the power output shaft of a gearbox, and then to realize the stalk conveying and pulling operation under the rotation of the toothed belt and the opposite rotation of the stalk pulling roller. A systematic kinematic analysis was conducted to determine the influencing factors in the working process. A field test was also carried out in a farmland in Korla City, Xinjiang Uygur Autonomous Region of China in October 2019. The soil firmness was 467 kPa, and the moisture content of the soil was 15%-20%, due to the perennial drought and little rain in the study area. The average height of cotton stalk was 700 mm, while, the plant spacing was 50 mm in a wide and narrow close planting mode. The power was from a CFD604A wheeled tractor with a calibrated power of 44.2 kW. The test was performed on the national standard of a harvester combine test(GB/T 8097-2008). A three-level quadratic regression orthogonal test was designed, where the forward velocity of the machine, the rod velocity of the deflector, and the speed of the stalk pulling roller were selected as the influencing factors, whereas, the leakage rate and plucking rate were the response factors. A response surface method was utilized to establish the regression equations for the relationship between the factors and assessment indexes. An optimal combination of parameters was obtained, while an experiment was also conducted to verify the mathematical model. The test results demonstrated that there were great effects of factors on the performance of horizontal-roller cotton stalk pulling. The significant effects on the leakage rate were ranked in a decreasing order: the forward velocity of the machine, the rod velocity of the deflector, and the speed of the stalk pulling roller. Correspondingly, the significant effects on the plucking rate were ranked in a decreasing order: the speed of the stalk pulling roller, the rod velocity of the deflector, and the forward velocity of the machine. The verification test indicated that the leakage rate of the cotton stalk was 5.24%, and the plucking rate was 3.75%,when the forward velocity of the machine was 0.68 m/s, the rod velocity of the deflector was 1.75 m/s, and the speed of the stalk pulling roller was 221 r/min. The optimal combination was better consistent with the predicted one in model optimization, indicating a reasonable structural design. The findings can provide a sound reference for the structural design and optimization of operation parameters in the horizontal-roller cotton stalk pulling machine. [ABSTRACT FROM AUTHOR]

Non-till farming has attracted increasing attention in developing sustainable agriculture, but the straws and the stubbles left over after harvest could block dispatch of fertilizer and seeds in seed drilling, which could detach the seeds and soil and result in nonuniform seed drilling both vertically and horizontally. Therefore, developing devices able to clean and crush the corn straw on seedbed before fertilization and seed drilling/spraying are demanded. However, the existing blade in such devices for laterally cutting the stubbles cannot completely clean and transport the stubble. The leftovers in soil make seed drilling problematic as they could block seed dispatch, increase energy consumption and, under certain circumstances, even make the sowing device unbale to operate. In order to resolve these problems, we designed a device to laterally cut and remove the stubbles from corn field. In this paper, we analyzed its efficacy in stubble clearance, soil disturbance, energy consumption, as well as conveying and throwing the cut/cleaned stubbles. The optimal structure of the stubble-cleaning blade and the working parameters of the device were calculated by taking the bending angle of the blade α, the transverse cutting edge B, and the angular velocity of the blade ω as determinants, and the stubble clearance ratio, soil disturbance ratio and equivalent energy consumption of the blade as quantitative indexes of its performance, using the three-factor and three-level orthogonal test and the fuzzy comprehensive evaluation method. The results showed that the stubble clearance ratio was significantly impacted by the bending angle, while the performance indexes were significantly impacted by the width and angular velocity of the blade. The factors that affected the performance of the device were ranked in the order of bending angle > transverse cutting edge > angular velocity. It was also found that soil disturbance ratio was mostly impacted by the transverse cutting edge, followed by the bending angle and the angular velocity, while the equivalent energy consumption was mostly affected the transverse cutting edge, followed by the bending angle and the velocity of the cutter tooth angle. The optimized results for the device operation were that when the operation speed was 7.2 km/h, the bending angle was 0.86 rad, the transverse cutting edge was 50 mm, and the angular velocity was 52 rad/s, the associated stubble clearance ratio was 94.3%, soil disturbance ratio was 54.3%, and the equivalent energy consumption was 3.4 kW. Under these conditions, clogging and straw entanglement did not occur. The results in this paper are helpful for designing devices to clear straw and stubbles left over after harvest in no-till farming. [ABSTRACT FROM AUTHOR]

Deep rotary tillage is a hot and difficult problem in the research field of tillage machinery. Scholars at home and abroad have made a lot of explorations on deep rotary tillage technology and theory. At present, deep rotary tillage is mainly realized through the following three methods: 1) plowing depth was increased by directly increasing the diameter of the knife roller; 2)Two-axis stratified rotary tillage. Two rows of knife rollers are set in front and back for the first rotary tillage of the former one, and then the latter one for further rotary tillage; 3) subsoil reverse rotary tillage, that is, deep tillage is achieved by sinking the knife shaft below the surface. These three methods can achieve the goal of deep rotation tillage, but they all have their own disadvantages. Considering the characteristics of oblique rotary tilling and reverse tilling, the principle of oblique submerged reverse rotary tillage is put forward in this paper, which can not only destroy the soil by “pull” but also reduce the heaping soil as well as make the central transmission box easy to sink subsoil, and realize low energy consumption deep tilling with short knife. The back-up amount of tilting rotary tilter directly depends on the performance of tilting rotary tilter. Oblique submerged reverse rotary tillage is put forward in this paper. It is important to study the mechanism of throwing soil to optimize the design of this machine. Oblique submerged reverse rotary tillage is a new type of rotary tillage. It is important to study the mechanism of throwing soil to optimize the design of inclined subterranean reversal rotary tiller. In this paper, a simulation model of SPH (Smoothed Particle Hydrodynamics) is established on the LS-DYNA platform. The model is used to reverse the rotary tillage in different working conditions. The simulation results show that the post-soil rate of different layers in the reverse rotation of different parameters under different parameters is obtained. The post-soil rate of different layers obtained under the same conditions and the post-casting of different layers obtained by the indoor soil trough test are obtained. The soil rate was compared and analyzed. The verification results show that the maximum simulation error is 12.50%, the minimum simulation error is 0.20%, and the average error is 3.09%. Applying the corrected simulation model, the oblique angle, the forward speed, the depth of the submerged soil and the speed of the cutter roll were taken as the four factors of the test, and three levels were taken for each factor. Afterwards, the throwing rate was measured and the tilt was set. The virtual orthogonal experiment of reversing the rotary tillage and throwing soil was conducted. The test results were analyzed by the range analysis method, the variance analysis method and the regression analysis method. The data analysis results show that the primary and secondary order of the impact rate after the impact is the subsoil depth and the oblique angle, the forward speed and the knife roll speed. The influence on the post-lost rate is not significant, and the mathematical relationship model of the subsoil depth, the oblique angle and the post-lost rate is obtained. According to the results of virtual experiment, the physical prototype of the inclined submersible soil reverse rotation tillage machine was optimized and the field experiment was carried out. The field test results showed that the reverse rotation of the inclined subterranean soil successfully solved the problem of the rotary tiller bracket and the central transmission box. And with the R175 standard rotary cultivator, the tilling depth of 20 cm was achieved, and deep tilling using short knife was realized in this paper. [ABSTRACT FROM AUTHOR]

Castor is one of the top ten oil crops in the world, which has a extremely high economic value. For a long time, the harvesting of castor bean has relied on manual operations, so the development of the castor industry have been greatly restricted by the high labor intensity and low efficiency. At present, there are few studies on harvesting machinery of castor, and the mechanization of castor harvesting is still in the initial stage. The existing castor harvesting equipments are not suitable for the growth features of castor, which has the problems of high loss rate and high damage rate. In order to solve these problems, a brush-roller harvesting method was proposed in this paper. The harvesting principle of brush-roller castor harvester is that the castor capsules are separated from the plant by the brushing force caused from the brush wire. According to the physical characteristics and planting mode of castor, the picking mechanism of brush-roller castor harvester was designed. Firstly, the structure of the picking mechanism was introduced, the picking mechanism is mainly composed of crop divider, brush roller, screw conveyor, transfer case, et. Then, the kinematic and mechanical analysis of the working process of the mechanism was carried out, so as to determine the structural parameters and working parameters of each part of the picking mechanism. In order to improve the harvesting quality of castor, we conducted a field experiment in October 2020 in Hohhot, Inner Mongolia. In the field experiment, Box-benhnken response surface design theory was used on the basis of single fator experiment to optimize the working parameters of the picking mechanism. The picking rate, the breakage rate and the impurity rate were used as the evaluation indexes of working quality. And the moving speed, the brush roller speed and the length of brush wire were taken as three factors influencing the working quality. The quadratic polynomial response surface regression model was established, and the influence of various factors on the response value was analyzed. From the regression model and variance analysis of regression equation, it could be seen that: lower moving speed, moderate brush roller speed, and shorter brush wire led to higher picking rate; Lower moving speed, lower brush roller speed, and longer brush wire led to lower breakage rate; Higher moving speed, lower brush roller speed, and longer brush wire led to lower impurity rate. The experiment results also showed that the significant effects of moving speed, length of brush wire and brush roller speed on increasing the picking rate were in a decreasing order. The significant effects of brush roller speed, length of brush wire and moving speed on reducing the breakage rate and the impurity rate were in a decreasing order. At the same time, the factors were multi-objective optimized comprehensively, and the optimization results were verified by experiments. The results showed that the optimum parameters were: 0.72 m/s for the moving speed, 372 r/min for the brush roller speed and 57 mm for the length of brush wire. Under these conditions, the picking rate was 91.36%, the breakage rate was 0.18%, and the impurity rate was 11.67%. The measured values of each index were in good agreement with the theoretical optimization values, which meant that the model established was reliable and could be used for optimization. The results can provide a reference for further improving the structure design and working parameters optimization of the brush-roller castor harvester. [ABSTRACT FROM AUTHOR]

The existing phase change material (PCM) devices of PCM refrigerated truck are mostly arranged on the top of the carriage, which has the problems of high gravity center and uncontrollable temperature and so on. In view of the above problems, a new type refrigerated truck was designed in this paper, which integrated phase change thermal storage unit, refrigeration system, heat-insulated carriage, air supply system and so on. The cold storage device was set independently in the front of the truck and was insulated. The phase change thermal storage unit used was 360 kg PCM (the phase transition temperature is -30 ºC and the latent heat of phase change is 175.3 kJ/kg), which used cheap electricity at night to store energy, when working, the temperature in carriage could be adjusted between -25-10 ºC. The simulation and tests of 2 working modes were carried out with the setting temperature of 0 and -18 ºC in a refrigerated sample. A computational fluid dynamics (CFD) simulation model of PCM refrigerated truck was built and the temperature field in carriage was simulated, the root mean square error and maximum absolute error between simulations and measurements of 2 working modes were 0.7 and 0.8 ºC, 1.1 and 1.2 ºC respectively, the simulated temperature calculated by the simulation model agreed well with the measured temperature, and the measured temperature near the air outlet in the carriage was slightly lower than the simulation temperature, while the measured temperature near the rear section was slightly higher than the simulation temperature, this was due to the fact that the simulation data were generally in an ideal state, but the cold leak was unavoidable at the return air outlet of the actual refrigerated truck and the heat leak (air leak) at the door. The test results showed that the new type of PCM refrigerated truck proposed in this paper could effectively control the temperature more than 10 h on the basis of sufficient cold storage. The average temperature fluctuated between 1.1-2.9 ºC and -14.8--16.9 ºC and the fluctuation ranges were 1.8 and 2.1 ºC under the 2 working modes. The lowest temperature in the carriage was located at the front of the carriage and close to both sides of the air outlet, the high temperature area was located at the top of the middle of the carriage and near the air inlet. The coefficient of temperature non-uniformity was less than 1.0 when the setting temperature in carriage was 0 ºC and was less than 0.4 when the setting temperature in carriage was -18 ºC. In terms of cooling time, it took 60 minutes when the carriage was set to 0 ºC and 90 minutes when the carriage was set to -18 ºC. The tested results showed that the average temperature fluctuation of the new type temperature controlled PCM refrigerated truck was 48.7% lower than that of the traditional PCM refrigeration truck, the coefficient of temperature non-uniformity was 50% lower, and the center of gravity was 25.9% lower than that of the overhead traditional PCM refrigeration truck. In addition, the temperature stability of the new type PCM refrigerated truck was better than that of the similar mechanical refrigerated truck because it didn’t need to defrost the evaporator during long-term operation. The new type PCM refrigerated truck can effectively reduce the transportation energy consumption and cost while guaranteeing the quality and safety of goods, and the research provided the basis for the optimization and application of the PCM refrigerated truck. [ABSTRACT FROM AUTHOR]

In order to develop a more efficient and universal flower auto-transplantation technique, an auto-transplantation mechanism with the integrated function of seedling pick-up and transplanting has been designed. This mechanism involves gear driving and two transplanting arms of the same structure. The gear driving system is made up of one semi-circle gear, four oval planet gears and concave-convex lock-up arc. It aims to move with the non uniform speed through the operation of planet gears and pulling and imbedding of concave-convex lock-up arc. The auto-transplantation arm includes the transplanting claw, convex gear and removing gear-gap parts. It transfers the whirling operation of planet gear into straight-line operation of pick-up seedling. The manual finger scratching and planting were simulated by two pins at the end of the seedling arm. The auto-transplantation mechanism combines the pick-up and planting. The transplanting trajectory and the location of pick-up and planting were special. Thus, it is essential to design new mechanism accordance with the movement of pick-up clip and achieve “Double beak sharp” trajectory. In this paper, we designed a device of bouncing clip to lengthen the trajectory to realize the function of pick-up and planting, and it could facilitate the integration of the planting. At the same time, when the claw moves nearly to the pot seedling, the seedling needle was inserted into the soil with a certain angle of inclination, which could effectively avoid the injury of the seedlings and the interference with the seedling box. Based on the kinematics characteristics of the mechanism, a corresponding mathematic model was established, and the Visual Basic 6.0 software was used to optimize the mechanism parameters. The program was used to analyze the influence of the parameters of mechanism on the trajectory and attitude of the “Double beak sharp". Finally, the best group of mechanism parameters was selected, and then the 3D design and components assembly were carried out based on SolidWorks 2015 software. Importing the 3D model to Adams, the trajectories of seedling needle could be obtained by the kinematics simulation. Finally, the prototype test was carried out and the test trajectory of the prototype was obtained by the test platform. Through the platform, the operation process was recorded by high-speed camera. Therefore, the trajectories of seedling needle could be tracked through the Bestcam picture analysis software. The results were basically the same among the simulation trajectory, the test trajectory of the prototype and the theoretical trajectory, which verified the correctness and feasibility of the design in this paper. Experimental research was carried out using the prototype, “Marigold chrysanthemum” seedlings were selected in the experiment, the basic composition of the pot seedling combines the pearl cave and peat mud, with the water component of 46%, the seedling tray were eight lines and 16 rows, both the length and width of seedling were 31 mm, and depth was 43 mm, and the test seedlings of marigold were 35 days, with the average height of 10 cm. The rotation speed of the mechanism was set as 35 r/min, its mean efficiency was 70 stems per minute. The obtained seedling success rate was 97.27%, while the transplanting success rate was 77.62%. It reflected the practicality of the integrated transplanting mechanism; the research could provide a reference for the key technology of automatic transplanting. [ABSTRACT FROM AUTHOR]

The performance of the supercharger volute directly affects the overall efficiency and capability of the turbocharger. It is important to improve the efficiency and performance of the turbocharger by reducing the flow resistance and decreasing the energy loss of the volute. Many measures are taken to improve the efficiency of the volute. Ocean spiral shells have evolved to reduce fluid resistance and cut down fluid energy loss during motion. In this paper, the spiral shell was taken as the biomimetic prototype, and the cavity data of the spiral shells were obtained by reverse engineering technology. The internal cavity cross-section data of shells were extracted in the range of 270 degrees. After the cross-section curves were optimized, they were taken as the section curves to construct the bionic volute. And then the volute bionic surface design was realized. The computational models of the prototype and bionic supercharger were finished. Taking the turbocharger volute of the gasoline engine with 1.5-liter displacement as the research object, the numerical analysis method was used to realize the performance difference between the bionic volute and the prototype volute. First, the prototype numerical model’s reliability was verified. Then the bionic volute was matched with the prototype turbine system. The numerical simulation of the bionic volute and the prototype volute was carried out in the range of common working conditions, and the difference between the two was explored from the microscopic flow field. During the modeling process, the A/R values of the two turbine volutes were the same, and the outlet width of the volute was consistent with the outlet diameter. The verification test was carried out on a QYZ-2 turbocharger test bench. The inlet flow of the compressor was measured by a double-line flowmeter, and the maximum measurement error was less than 2% FS. Both the inlet and the outlet of the compressor were provided with a pressure sensor and a temperature sensor. The turbine inlet was provided with a turbine inlet pressure sensor and an intake temperature sensor, and the turbine outlet had a turbine exhaust pressure sensor and an exhaust temperature sensor in the extension duct. The maximum error of the pressure sensor was less than 2.5% FS, and the maximum error of the temperature sensor was less than 3% FS. The maximum error of the simulation calculation was within the allowable range. The simulation results showed that the simulation model was in good agreement with the test bench, and has good reliability. Therefore, the numerical model can meet the requirements of subsequent research. In the simulation, 12×104 r/min, 16×104 r/min and 20×104 r/min were selected to represent the low, medium and high operation speed of turbine respectively. The evaluation parameters included turbine efficiency, flow characteristics and total volute loss coefficient. The results showed that the turbine flow capacity increases with the increase of the expansion ratio increase. And the turbine flow characteristics of the two volutes were basically the same. The results showed that the turbine efficiency can be increased by 3% and by up to 5% under the condition of keeping the same turbine flow capacity matching two volutes. The flow field analysis results showed that the bionic optimization volute reduces the flow loss near the inner surface of the volute and the airflow friction in the flow channel. And the flow resistance was small, the whole flow in the bionic volute was smooth and uniform, and there was no swirling flow. Therefore, the turbine efficiency can be significantly improved. The bionic design method used in this paper had a significant improvement on turbocharger turbine performance, and can provide reference and method innovation for the design and optimization of automotive and agricultural machinery turbocharging systems. [ABSTRACT FROM AUTHOR]

The degree of automation of domestic combine harvester is low, and the operation is complex, it is difficult for workers to understand the actual adjustment of working parts. Crop height, crop length, height of the ground and the lack of consistency in course of project led to the continuous adjustment of harvester's joystick. The traditional operation method, in which experiences are excessively relied on, cannot meet the requirements of automatic operation of domestic-made combine harvester. The current operation method is an obstacle to the development of the automatic control of the combine harvester. In this paper, a device of adjusting combine harvester header parameters was designed. The header parameters include height of header, height of reel, position of reel and speed of reel. The control function of header parameters adjusting device is to adjust height of header, height of reel, position and speed of reel. The header parameter adjusting device was composed of sensor modules, PLC control units, display modules, key module, header drive parts module and so on. The sensor modules were used to detect the parameter of header which include height of header, height of reel, position of reel, speed of reel and forward speed. Sensor modules detect the signal inputed into PLC control unit. PLC control unit is the core component of the adjusting device. PLC performs data operation and processing. Using touch display screen as human-computer interaction tools, which communicates with PLC. The display interface includes parameters displaying and setting, and displayed parameters include header parameter, operating speed, crop height and so on. The key module adopts self-reset and self-locking switch to realize manual and automatic function signal input. At the same time, PLC receives the key information and make judgments, and then sends the control signal to drive header hydraulic system to carry out the movement of the mechanism. Header drive parts modules include lectromagnetic directional valve and proportional solenoid valve, which adopts the hydraulic control principle. High reel speed has a large impact on crop yield and increase grain losses. It is difficult to push crops to header and proceed to the next step of threshing, clearing and collection at low reel speed, and it is difficult to match the change of operation speed with the reel speed. In this paper, an automatic control method of reel speed was presented. By analyzing the working process of reel, a mathematical model of reel speed was established, and fuzzy PID algorithm is used to realize the automatic control of reel speed. The header parameter adjusting device was installed on the test prototype, and the regulatory tests, data records and data analysis were carried out. The test results showed that header height, reel height, reel position and reel speed could be electrically controlled by the header parameter adjusting device. Relative adjustment errors of header height, reel height, reel position and reel speed were 7.4%, 3.4%, 2.0% and 7.8% respectively. The operation speed of maximum relative error was 3.4%. The response time is less than 0.8 s, and the adjustment time is less than 1.7 s. The system was proved to meet the design requirements of header parameter controller of combine harvester. The research results can be applied in intelligent operation of combine harvester. [ABSTRACT FROM AUTHOR]

As a main grain production equipment, the combine wheat harvester plays an important role in grain production, and its technological development level is an important indicator of the degree of agricultural modernization. However, during the harvesting process, the working parts of the harvester interact with the crop to be harvested, so that the dust originally attached to the surface of the crop is disturbed and separated from the surface of the organism, forming floating and flying dust, some of which are scattered around the harvester, seriously affecting The driver’s body is healthy; some infected plants carry diseased dust, which is more harmful to the human body; more dust is dispersed in the air with the wind, causing a wider range of air pollution and increasing the amount of inhalable particles in the air. This has become one of the sources of air pollution during the crop harvest season. In order to understand the dust generation status and the characteristics of the dust composition, this paper first conducts the dust concentration and distribution test on the operation site of the combine wheat harvester .The result is as the header and tail of harvester are the main areas where dust is generated, Excessive dust mass concentration will harm the health of workers .The characteristics of the dust sample was tested results as follows: the proportions of dust with a particle size of 10μm and 100μm or less are 45% and 92%, the dust is mostly composed of minerals, grease and carbohydrates. The dust measurement test revealed for the first time the dust generation and dust composition characteristics of combine wheat harvester operations in the rice-wheat (oil) rotation area in southern my country. On this basis, a dust suppression system installed on the combine wheat harvester was designed. The system adopts the working principle of negative pressure dust suction and filter cartridge dust collection. The system utilizes the power of the existing combine wheat harvester and can change the working parameters of the fan at any time to meet a variety of field working conditions. Conduct field tests on the dust suppression system. Through theoretical analysis to determine the main factors that affect the efficiency of the dust suppression system. Taking the harvester header dust suppression efficiency and harvester tail dust suppression efficiency as the test indicators, and the harvester speed, fan speed and environment humidity as the test factors. Using Box-Behnken central combination test method, the three-factor and three-level test are carried out. A mathematical regression model of various factors and test indicators was established. Through variance analysis and response surface analysis, the influence of harvester speed, fan speed and environment humidity on the test indicators is obtained. Use Design-Export8.0.6.1 data analysis software to fitting and optimization analysis of the test results, the optimal parameter combination is obtained as follows: harvester speed 3.73 km/h, fan speed 3 507 r/min, and ambient humidity 56%. On this condition, the efficiency of the header dust suppression is 76.8%,the efficiency of the tail dust suppression is 79.6%. The optimal working parameters are tested and verified to verify the feasibility of optimizing the optimal parameter combination, the minimum fan speed of the dust suppression system to meet the dust suppression requirements under difficult working conditions is 3 332 r/min. This research can provide a basis for the design of the harvester dust suppression system. [ABSTRACT FROM AUTHOR]

The banana stalks are rich in fiber, and the existing returning machines for banana straw and stubble crushed in China have generated a few problems such as overly severe cutting resistance, the fiber of banana straw winding crushing blade roller on the returning machine, working on the unstable condition and serious fuel consumption. In order to deal with the above problems which the existing choppers met with in the working process, with the help of theoretical study and the analysis on the planting model for banana in Hainan Province, this paper put forward a returning method that the moving knives on the front knife roller were used to crush banana straws and the flail knives on the back knife roller were used to break stubble under the earth. The rotational direction of stubble crushing roller in the returning machine was same to the forward direction of the machine providing power, while the rotational direction of straw crushing roller was contrary to that of stubble crushing roller. On the basis of establishing theoretical model and the analysis on the planting model for banana in southern China, the key shaped parameters of the sliding-cutting blade and the structural parameters of crushing blade rollers were determined respectively. Besides, the sliding-cutting and anti-twining returning device for banana straw was put forward. The overall structure and working principle of sliding-cutting and anti-twining returning device were described. The performance of crushing banana straw and the power consumption were evaluated by simulating the breaking operation of banana straw in farmland through a bench test driven by double electric motors. The machine was composed of electrical motors, a tractor powered by electricity, the frame of machines, the straw crushing device and the stubble crushing device. Through Design-Expert software, a quadratic orthogonal rotating experiment was performed. Based on the variance analysis and regression fitting, a multiple regression equation was gained, presenting the effects of the working speed of the returning device, the rotating speed of rotating roller of moving knives and the rotating speed of rotating shaft of stubble breaking on the qualified rate of straw crushing and power consumption. It could be seen that the rotating speed of rotating roller of moving knives had the most influential effect, followed by the rotating speed of rotating shaft of stubble breaking, and the working speed of the returning device had the least influence on the qualified rate of straw chopping. The operation condition was optimized by applying the response surface method. The optimum factors for straw and stubble crushing process were as follows: The rotating speed of rotating roller of moving knives was 1 600 r/min, the rotating speed of rotating shaft of stubble breaking was 500 r/min, and the working speed of the returning device was 1.39 m/s. Based on the theoretical analysis, the higher qualified rate of straw crushing was achieved under the faster rotating speed of rotating roller of moving knives. The smaller power consummation was obtained under the lower rotating speed of rotating roller of moving knives and the lower rotating speed of rotating shaft of stubble breaking. Under the optimal condition, the corresponding qualified rate of straw crushing and power consumption were 95.2%, and 4.96 kW, respectively. The differences between the experimental and the analytical values of the qualified rate of straw chopping and power consumption were 0.31 percentage points and 0.27%, respectively, which indicated that the software analytical value was in great agreement with the experimental value. And by field test, qualified rate of straw crushing of machine proposed in this paper was higher by 1.94 percentage points and power consumption was lower by 11.3%, compared with vertical flail banana stalk crushing machine. Its successful implementation can greatly improve the production efficiency for crushing banana straw and stubble on one hand, and on the other hand prevent the pollution brought by deserted banana straw putridity. [ABSTRACT FROM AUTHOR]

Large-scale grain drying technology has a nearly 50 years of development history in China. There are concurrent flow dryer, countercurrent dryer, cross flow dryer and mixed flow dryer, which meet the actual needs in various fields. But compared with the similar foreign products, there are many defects on our grain dryer, such as low manufacturing technology, low level of automation and high energy consumption. The co-current flow dryer has the characteristics of dry uniformity, low unit heat consumption and high productivity. But there are some defects, such as poor control of drying quality, high cost of drying and environmental pollution. These shortcomings are not conducive to the sustainable development of agricultural production and ecological environment. Therefore, from the perspectives of the structure and the process of the high temperature grain dryer, combining energy saving with conservation of grain quality is the key to the development of modern grain drying technology. Generally, the form of air supply in large-scale grain dryer is positive pressure, with easy maintenance and adjustment. The negative pressure air supply technology is only used for small cycle dryers. In this paper, the negative pressure technology in the large-scale grain drying system was applied for the first time. Negative pressure drying can effectively solve the internal control problems of the drying process based on the theory of micro pressure. Negative pressure is beneficial to collect the grain dust, create excellent production environment and realize safe production. The losses of static pressure and dynamic pressure are relatively small in the process of negative pressure drying, and this technology can reduce power consumption, and is easier to realize intelligent control of air volume and air medium parameters. In order to reduce primary energy consumption and improve corn drying process capacity, combined with grain drying characteristics in cold region, 5HFS-10 type negative pressure grain dryer was designed based on the principle of negative pressure drying. This drying technology combined the multi-stage concurrent flow and countercurrent flow, and a set of advanced structure and control system were applied in this drier. The parallel dilated fan was combined with variable diameter cornute duct, the cold air quota regulation agencies were coordinated, online work parameters were real-time collected with multi sensors, the adaptive control system was adopted, and all of these completed the intelligent quality-guaranteeing drying production of the staple food crop. In this paper the calculation of drying parameters and structure parameters was carried out providing the theory basis for the comprehensive evaluation and the design of negative pressure dryer. Production test shows that the machine’s work performance is good, its energy saving is significant, and it has good drying quality, unit mass of low cost, high degree of automation, and so on. The deviation of the moisture of discharged grain is less than ±0.5% w.b. Compared with the traditional positive pressure air supply dryer, this dryer saves the power by more than 20%, and reduces the production cost by more than 12%. The operating performance can perfectly meet the requirements of farm drying and large-scale drying technique. It provides the theoretical basis for the development of energy-saving intelligent grain dryer. [ABSTRACT FROM AUTHOR]

At present, the vegetable planted by seedling cultivation and transplantation accounts for more than 60% of the total vegetable planting. It has the advantages of high and stable yield, climate compensation and land use efficiency improvement. However, vegetable production belongs to labor-intensive industry, the increasingly serious problem of difficult employment leads to the fact that the labor cost of vegetable production accounts for more than 50% of the total cost of vegetable production, which has become the main factor restricting its development. Therefore, it is an inevitable trend for the sustainable development of vegetable industry to study the mechanization and automation of vegetable transplantation. Taking and dropping seedlings is a very important link in vegetable transplanting. In view of the problems of automatic transplanting of vegetable seedlings in China, such as the complex and easy to fail of seedling picking and throwing device, a kind of oblique inserting plug seedling taking and throwing device is designed in this paper. The principle of picking and seeding device was analyzed, and then the location of taking point, throwing point and any point in the process of picking seedlings were selected. The projection method was used to design the device, and the structure and working parameters were determined. The length of the frame, driven rod, connecting rod, driving rod and seedling clip were 122, 196, 80, 186 and 227 mm respectively. In order to ensure that the device has a good effect of taking and throwing seedlings, the tilt angle of the seedling tray and the parameters of the seedling clamping into the hole are designed, and the movement process is analyzed. The feasibility of the scheme is verified by comparing the simulation trace curve with the actual test trace curve. According to the mathematical model of the working process of seedling taking and throwing device, kinematics analysis and simulation are carried out, and the position of seeding taking and throwing, speed and acceleration curve of the seedling clamp endpoint are obtained, the design meets the requirements of automatic transplanting. Considering the factors affecting the effect of taking and throwing seedlings, the spring stiffness coefficient, rotational speed of the active rod and the inclination angle of the seedling tray are selected as the experimental factors, and the orthogonal experiment was carried out. The results show that the best effect is obtained when the spring stiffness coefficient is 500 N/m, the speed of the active rod is 12 r/min, and the inclination angle of the seedling tray is 45°. Repeated experiments were conducted with the optimum parameters, the results show that the broken rate of substrates is 3.13%, the expulsion rate of seedlings is 2.43%, the success rate of seedling taking and throwing is 94.44%, the reliability of the device is high. The design provides a reference for the study of full automatic transplanting. [ABSTRACT FROM AUTHOR]

Residual plastic films degrade soil structure and have a detrimental impact on seed germination and the subsequent seedling development and establishment, thereby leading to reductions in crop yield. Removing the films from soil prior to sowing is hence critical to safeguarding crop growth. This paper presents a roller-type device incorporated into ploughing machine to simultaneously strip, collect the films from the soil and then unload them in a row prior to sowing. The device was nail-teeth designed to pick up and strip the residual films. The optimal combination of the structure and working parameters of the device was theoretically analyze using a quadratic regression orthogonal rotation test by taking forward speed of the machine, rotating speed of film pick up roller and rotating speed of film stripping shaft as determinants, and the efficiency of both film pick up rate and film stripping rate to represent the performance of the device. The significance of each determinant in affecting the rate of film pick up and stripping was analyzed using the Design-Expert software. The results show that in terms of impact on film pick up rate, the three determinants were ranked in the order of machine forward speed > rotating speed of film pick up roller > rotating speed of film stripping shaft, while in terms of impact on film stripping rate, the determinants were ranked in the order of rotating speed of film stripping shaft > rotating speed of film pick up roller > machine forward speed. Optimization calculated using MATLAB showed that the optimal working parameters were: device forward speed 1.62 m/s, rotating speed of film pick up roller 90 r/min, and rotating speed of film stripping shaft 1 055 r/min. We verified these optimal results against field experiments and found that the film pick up and film stripping rate was 70.56% and 82.96%, respectively. The differences between the experimental results and the calculated results was small, indicating that the optimized working parameters were reliable and robust. [ABSTRACT FROM AUTHOR]

The problem of environmental pollution caused by excessive use of chemical fertilizers has seriously restricted the sustainable development of green-oriented agriculture in China. Quantitative and uniform mechanized fertilization as an important measure to improve the utilization rate of chemical fertilizers and reduce the amount of chemical fertilizers has become an important way to solve agricultural environmental pollution. In this paper, a spiral disturbance cone centrifugal chemical fertilizer apparatus was designed to solve the problem of precision fertilization due to the insufficient fluency and stability of the fertilizer apparatus fertilizing processes and insufficient uniformity of fertilizer discharge. First of all, the design principles and working principles of the fertilizer apparatus is illustrated. Then the structural parameters of the spirally disturbance cup and curved cone disk are designed, based on the physical and mechanical properties of the granular fertilizer and the requirement of fertilization for rapeseed sowing. Moreover, fluency, uniformity and stability of the fertilizing performance are verified by bench test and field test. The SINO-AGRI fertilizer, STANLEY fertilizer and EZHONG fertilizer are respectively used as experimental materials to carry out the bench test of the fertilizer apparatus. The rotational speed of cone disc measured by SW6234C laser speedometer, there are total 6 levels, are 80, 90, 100, 110, 120, 130 r/min. Coefficient of variation of fertilizing amount consistency in every row, the coefficient of variation of fertilizing amount stability and coefficient of fertilizing amount consistency in same row are used as the evaluation index in the bench test for evaluating fluency, uniformity and stability of the fertilizing performance. The test results of bench show that the variation coefficient of fertilizing amount in every row of three compound fertilizers is below 11.5%. The coefficient of variation of fertilizing stability under chemical fertilizer conditions with different rotational speeds and physical and mechanical properties is below 6.3%, and the variation coefficient of fertilizing amount in same row is above 93%. Therefore, the fertilizer apparatus meets the quality requirements of fertilizer discharge. Meanwhile, variation coefficient of fertilizing amount in every row is 9.82% when the rotational speed of cone is low and the fertilizer apparatus is tilted, that means that the fertilizer apparatus still has better fertilizing performance in the inclined state. The adaptability applied to a narrow-width fertilizing machine of less than 8 rows is weak. The cone disc is successively rotated through the 1 to 8 row of fertilizer tube. When the rotational speed of cone disc is low, the next discharge tube of the blocked fertilizer pipe has a larger amount of fertilizer, the amount of chemical fertilizer in the other fertilizer pipes is basically the same, and the difference in the amount of fertilizer discharged from each row of fertilizer pipes is small. While the rotational speed of cone disc is high, the previous discharge tube of blocked has a larger amount of fertilizer, the difference between the fertilizing amount of this discharge tube and other discharge tube is larger, the amount of fertilizer in the other fertilizer tube is basically same. Furthermore, the field test was carried out to verify the fertilizing performance of the spiral disturbance cone centrifugal fertilizer apparatus. The results of field experiment show that the variation coefficient of fertilizing amount in every row is below 7.9%, the coefficient of variation of fertilizing stability is below 5.3%, the variation coefficient of fertilizing amount in same row is above 93.5%. This research provides effective technical support for chemical fertilizer reduction and precision fertilization. [ABSTRACT FROM AUTHOR]

The soil-covering and press wheel are the main parts of the corn planter, and their performances are directly related to the growth and the output of the corn. The device with the functions of soil covering and soil compaction can improve the soil moisture content after planting and simplify the structure of machine. The squeeze-type coverer is a typical device with the functions of soil covering and soil compaction. But due to that the contact area is too small to bring the poor stability of soil-covering and soil-compacting during work process, the squeeze-type coverer is often used on no-till planter. A new type of soil-covering and soil-compacting device for corn planter was designed in this paper. The device was composed of 2 soil-covering-pressing wheels with cone-shaped structure, and realized the functions of soil-covering and soil-compacting depending on the extrusion force of soil produced by soil-covering-pressing wheel during planting. The main structure parameters of the soil-covering and soil-compacting device were determined through theoretical analysis and experiment of double-disk opener, which were mean diameter of 350 mm, width of the horizontal part of single soil-covering-pressing wheel of 20 mm, width of the inclined surface of single cover-press wheel of 70 mm, and the value range of horizontal interval of left and right soil-covering-pressing wheel of less than 29 mm. The leaning angle of soil-covering-pressing wheel was determined through theoretical analysis of soil-covering process based on the shape of soil furrows, which meant the leaning angle was about less than 20°. Based on the agronomic requirement of soil-compacting, the range of external load was about 609-790 N. Through analyzing, it was found that the external load, the horizontal interval between left and right soil-covering-pressing wheel and the leaning angle were the main influencing factors on the functions of soil-covering and soil-compacting of the device. Taking the 3 indices as the experimental factors using Design-Expert software, the Box-Benhnken experiments of 3 factors and 3 levels were conducted, and the results showed that the order of the influence of the factors on the soil compactness in the top 5 cm soil layer of the seed furrow from high to low was the external load, the horizontal interval between left and right soil-covering-pressing wheel and the leaning angle. The order of the influence of the factors on thickness of covering soil was the leaning angle, the load and the horizontal interval between left and right soil-covering-pressing wheel. The optimal parameter combination of the device was the external load of 900 N, the horizontal interval between left and right soil-covering-pressing wheel of 13 mm and the leaning angle of 16°. Verification testing indicated that the soil compactness in the top 5 cm soil layer of the seed furrow was (43.8±1.9) kPa, the coefficient of variation was 4.3%, and the thickness of covering soil was (32.9±2.3) mm with the coefficient of variation of 6.9%. The soil-covering and soil-compacting device designed in this paper has good performance of soil-covering, soil-compacting and working stability. This study can provide a reference for the design of planters. [ABSTRACT FROM AUTHOR]

Potato is one of the fourth staple food crops in China. Medium tillage operations such as loosening soil, crushing soil, soil cultivation and weeding during the early seedling and middle growth stages of potatoes have a great influence on potato yield. The main functions of mid-tillage include loosening soil, enhancing soil permeability, preserving soil moisture and drought resistance, improving soil physical properties, improving soil fertility and eliminating weeds, and mid-tillage can resist lodging and increase crop yield. Potato mid-tillage production has a large amount of work and its operation process is limited by growing crops. Therefore, it is of great significance to develop a potato mid-tillage machine with high working efficiency and good operation effect. Aiming at the problems of low soil breaking rate, weeding rate and poor soil cultivation effect of traditional hoe-shovel type cultivator under the condition of soil cohesion and compaction, a driving potato cultivator which integrates the functions of deep loosening and crushing soil, weed eradication, side deep fertilization, soil cultivation and ridging is designed in this paper, the key parts of the machine and the structure of the deep loosening shovel, soil crusher and soil cultivator are designed and analysed. On the basis of design and analysis, field experiments are carried out. The machine is mainly composed of deep loose soil device, soil conservation device, fertilization device and transmission system. Eight blade dishes are installed symmetrically on the left and right sides of the blade shaft. Each blade dish is fixed with two soil breaking blades. The length of the soil breaking blade is 242 mm, the width of the soil breaking blade is 40 mm and the thickness of the soil breaking blade is 10 mm. In order to adapt to different kind of soil conditions, the adjustment range of the subsolier is 150-250 mm, the height of the subsolier is 560 mm. The test results show that the soil breaking rate of driving-type cultivator is 95.1%, weeding rate is 96.3% and the injury rate is 1.2%, the soil bulkiness is 49.3%, and the fuel consumption is 13.2 kg/hm2, which met the relevant performance evaluation indicators. Compared with the traditional hoe-shovel type cultivator, the soil breaking rate of, weeding rate and soil bulkiness of the driving-type cultivator increase by 3.3%, 3.1% and 7.8%, injury rate and fuel consumption decrease by 1.6% and 28%. The operation effect of the driving-type cultivator has been improved significantly, exceeding the national standards and meeting the requirements of potato cultivation and agronomy. This research results can provide a reference for the development of potato cultivators. [ABSTRACT FROM AUTHOR]

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]

Laying duck raising and duck egg processing belong to traditional superior animal husbandry in China. Dirty surface of duck eggs will shorten storage time and increase subsequent cleaning cost. The bottom wire mesh is an important part of the furnished cage and is closely related to duck egg cleanliness. Aiming to solve the problem that the surface of duck egg shell is seriously polluted during the process of raising laying duck in the cascading cage-rearing equipment, the authors optimized the dimension parameters of the bottom wire mesh in this paper. Based on the analysis of duck egg movement on the bottom wire mesh, a kinematics simulation mode was developed to determine the appropriate range of the bottom wire mesh slope using dichotomy depending on whether duck eggs roll out of the furnished cage. The steeper the slope, the easier it was for the duck eggs to roll onto the conveyor belt. But if the slope was too large, the duck eggs might collide with the egg on the conveyor belt to cause damage. Meeting the above conditions, the appropriate slope value was chosen. According to the longitudinal spacing in bottom wire mesh, the lateral spacing in bottom wire mesh, the diameter in bottom wire mesh, the total deformation maximum and the mass of the bottom wire mesh, mathematical optimization model of the bottom wire mesh was established. The authors adopted an analysis method of 3 factors and 4 levels corresponding surface, and the dimension parameters of the bottom wire mesh were optimized based on the total deformation maximum response surface. The optimum solution in the results had the maximum area of the leakage hole in the bottom wire mesh. The finite element software ANSYS Workbench was used as the computing platform in this analysis. After optimization, the slope increased to 8.5°, the area of the leakage hole increased by 29.2%, and the total deformation maximum decreased by 18.1%. The area of the leakage hole bears on the cleanliness of the duck egg, the larger the area, the cleaner they were. This was because that duck dropping passed through the hole and fell onto the manure without sticking to the bottom wire mesh to soil the duck egg. Smaller deformation meant better structural stability. To test the feasibility of the optimization result, this research team experimented on cage-rearing laying duck using the bottom wire mesh optimized in a welfare duck farm of Hubei Shendan Healthy Food Company. The experiment included 384 ducks weighting in (1 350±50) g and lasted for a whole month. Ducks were divided into test group and control group living in the same environment. 2 ducks were raised in every cage. The results showed that the bottom wire mesh had a significant positive effect on duck egg cleanliness (P<0.01), and the average cleanliness of duck egg in the test group was 1.21 which was lower than 2.01 in the control group. It’s known that cleanliness had negative correlation with effect. Before and after optimization, the bottom wire mesh had no significant effect on duck feather damage, laying rate and duck egg breakage rate. During the experiment, there was no obvious mass duck leg injuries in the experimental group, and the rate of death and elimination were in a reasonable interval in comparison with the average in the farm. This study solved the problem that the surface of duck egg shell was seriously polluted, and has high practical value. Meanwhile, this research method can provide reference for the development of furnished cage wire for poultry cage-rearing equipment. [ABSTRACT FROM AUTHOR]

Currently, there is a large amount of maize straw mulching on farmland in Northeast China. Under conditions of conservation tillage, there are large amount of straws mulching on soil surface that it required the opener of no-tillage seeder should have excellent functions for straw cutting, anti-blocking and seedbed cleaning, as well as stable ditching performance that can keep the ditch depth and the ditch width fluctuating uniformly. During the mechanized sowing period, maize no-tillage seeder with sharp angle opener is facing the problem of seriously clogged up and high-power consumption, while planter with disc opener shows little disturbance to soil under straw mulching condition and a good trafficability. However, large positive pressure and counterweight that auxiliary ditching operation will be needed for general double disc opener, with poor soil entry ability and straw blockage problem, especially in the conditions of large amount of straw mulching on the surface of farmland, the disc opener will press the straw into furrow instead of cutting them off when ditching in farmland with quantities of straw mulching. Based on the above issues, an asymmetric large-small double disc ditching device for corn seeding was put forward in this paper, which is mainly composed of large disc, small disc, direct-axis, oblique-axis and rack. The large disc and the small disc are arranged asymmetrically, which forming rotating connection with the rack by direct-axis and oblique-axis respectively. The rotating plane of the large disc is perpendicular to the horizontal plane and the small disc is inclined setting. The angle between the rotating plane of the small disc and the vertical plane is 8° (the working inclination of small disc), besides, the angle between the rotating plane of the small disc and the direction of the ditching operation is 12° (the working deflection of small disc). When working, large disc mounted on front of small disc cuts maize straw and stubble in advance, and then small disc that staggered set in the rear-lower part removes straws and ditches seed furrows, in order to prepare clean seedbeds for maize sowing. Based on mechanical analysis and kinematics analysis, diameter of large disc and small disc was obtained, which was 460 mm and 360 mm respectively. The gathering point located on the front edge of the small disc that gathering point angle of small disc is 56°, meanwhile the gathering point located in the interior of large disc with radius of 190 mm, gathering point angle of 56°. The performance of asymmetric large-small double disc ditching device was tested by EDEM simulations and field experiments without straw mulching on soil in advance beforehand, and the difference of ditching depth and ditching width were 2.15 mm and 1.62 mm respectively. Results of field experiments under wheat straw mulching showed that asymmetric large-small double disc ditching device could realize relatively stable and reliable ditching effect. Under straw mulching conditions, the ditching device could meet the requirements of no-tillage maize sowing, the average ditching depth was 71.41 mm and the average ditching width was 38.27 mm. Besides, anti-blocking performance of asymmetric large-small double disc ditching device was tested in field experiments with 4 straw mulching amount(full-straw coverage, small amount of coverage (0.66 kg/m2), middle amount of coverage (1.64 kg/m2), large amount of coverage (2.18 kg/m2)), at 2 different working speeds (4 km/h, 6 km/h). Anti-blocking tests indicated that the ditching device was operating smoothly, and there was no obvious blockage and continuous breaking in the ditch overall, which revealed better straw-cutting capability and enhanced penetrability. The device meets the requirements of agronomic production and standards of maize sowing, and this research can provide theoretical support and technical basis for the development of maize no-tillage planter. [ABSTRACT FROM AUTHOR]

Transplanting trees is a high intensity work, which is necessary to be mechanized in modern society. At present, most of the tree transplantation machines are developed on the basis of general excavators, which have the disadvantages of high power requirement and high energy consumption. Its performance can be improved in 2 aspects, which are the power matching of the whole machine and the resistance reduction during digging process. The commonly used tree transplantation machines in the market dig holes with a shovel. The shovel is an important part of the machine. The machine’s digging performance and the energy consumption are determined by the size, shape and quantity of shovel. In order to reduce the resistance of the shovel, scholars have carried out a series of researches on bionic structural and surface. It is noticed that some animals living in soil for a long time have the characteristics such as geometric non-smooth units on the surface of theirs body, which is the main reasons for reducing the viscosity and resistance, and the soil animal-ground beetle is a typical representative of this feature. In order to reduce the resistance and the energy consumption effectively when digging soil, the paper analyzed the force of the shovel and established the mechanical model according to the working conditions and characteristics. Solidworks and ANSYS/LS-DYNA software were used to establish the numerical model of the shovel and soil, digging process was simulated in software and the force of the shovel was calculated. Through numerical simulation, the digging angle of the shovel was optimized; it was found that the optimal digging angle of the shovel is 83°. Then, a new type of bionic shovel was designed to simulate the surface structure of the soil organ of soil animal-ground beetle, there were many convex units with the shape of sphere on the surface of the shovel, and the size, shape and distribution of the convex units is main considered. Under the condition that the digging angle of the shovel is 83°, the best parameters of the bionic shovel were obtained by numerical optimization: the convex diameter is 14 mm, the center distance of the convex is 28 mm, and the height of the convex is 4 mm. The bionic shovel was developed according to the best parameters and was installed on the prototype of the tree transplant machine to carry out the comparison test. Because the shovel is operating inside the soil, it is impossible to accurately measure the force by sticking the strain gauge on the surface of the shovel, so the hydraulic cylinder pressure of the driving was tested to reflect the force of the shovel indirectly, that is, the force of shovel was equal to the inlet pressure multiply with the inlet area of hydraulic cylinder. 5 times experiment were carried, and the maximum and average force of shovel were recorded: The maximum force of bionic shovel was 2.474 kN, compared with 2.783 kN of the original shovel, the force was reduced by 0.309 kN, the average force reduced 0.512 kN. The results showed that the bionic shovel can effectively reduce the resistance of 11.11%. The bionic shovel is proved to have a good resistance reduction characteristic, which can provide technical support for energy-saving and consumption reduction of the tree transplant machine. [ABSTRACT FROM AUTHOR]

In order to solve the problem that seedlings cultivated by pie-shaped compression matrix can not be planted by the existing transplanter, a semi-automatic compression matrix seedling transplanter was designed in this paper by mimicking the artificially transplanting method of putting seedlings after punching a hole. The compression matrix type seedling transplanter mainly consists of a ground wheel, a swing mechanism, a ratchet wheel, a hole puncher, a displacement mechanism, a seedling clamping mechanism, a conveying device, a transmission system, a rack, and so on. The physical dimensions and mechanical properties of the compression matrix type seedling are the key basis for the design of the seedling planting schemes and structures. Taking watermelon seedlings as the research object, the dimensions of the seedlings were measured, and the friction coefficient of the compression matrix with different water contents and the compressive strength of the compression matrix were determined. The coefficients of friction between the slideways and the flanks of watermelon seedlings with 2 groups of different water contents were determined to be 0.755 and 0.634 respectively by single-factor tests. The relationship between the compression load and the compression amount of the 2 groups was also analyzed. When the load is 0-5 N, as the surface of the seedling is in point contact with the semi-circular thin metal at the initial stage of compression, the compression load increases evenly and the amount increases rapidly. When the load is between 5 and 20 N, as the surface of the seedling is in surface contact with the semi-circular thin metal, the compression load increases evenly with less impact on compression. When the load is greater than 25 N, some external cracks are observed on the surface of the seeding during the test. Comparing the 2 tests, it can be seen that the seedling with high water content is not easily destroyed. The swing mechanism is optimized according to the known movement law of the initial angle of the crank and the output angle of the driven rod. The dimensions of optimized parts are 57, 161, 79 and 170 mm, respectively. When the crank rotates one revolution of 360°, the reciprocating swing angle of the driven rod is 92.3°, which satisfies the working requirements of the four-equal-part ratchet wheel mechanism. The structure and specific size parameters of the hole puncher are determined according to the measurement size and planting depth requirements of the watermelon seedling. The width of the edge surface is 1.5 mm. The inner diameter of the small end is 64 mm, and the height of the tapered part of the hole puncher is 65 mm, and when the incision angle is 21°, the inner diameter of the big end is about 114 mm. The structure parameters of the seedling clamping mechanism are determined according to the mechanical properties and the dimension of watermelon seedling. And it is also concluded that the seedling’s matrix can overcome the self-gravity of the seedling, which ensures that the seedling clamping mechanism can securely grip the seedlings when transplanting with a clamping force of 26 N. The seedling conveying device and the planting holding device are driven by the same power source, ensuring that the feeding speed of the seedlings is synchronized with taking seedling action of the planting holding device. The conveyor belt is used to transport the seedlings, and the conveyor belt was designed to send seedlings at a speed of 40 plants per minute. Using a compression matrix for field planting functional verification tests, the average plant spacing is 98.6 cm when the transplanter moves at a stable speed of 2.1-2.6 km/h. The pass rate of the plant spacing is 90.62% and the lodging rate is 21.9% which is slightly higher. In the follow-up study, dual-ground-wheel driving would be used to improve the reliability of the transmission and obtain uniform spacing; a hole shape with the same level and the same depth should be acquired, and the lodging rate after the landing of pie-shaped matrix would be reduced by increasing the copying mechanism and optimizing the shape and structural parameters of the hole puncher. [ABSTRACT FROM AUTHOR]

Maize is one of the main crops in the Northeast China. The agronomic requirement of maize planting in this region is stubble cleaning and ridging before sowing. Stubble cleaning can crush crop straw, which could promote the growth speed of maize and increase the organic matter content in soil. Ridging can increase the surface area of the land, which is beneficial for improving the soil temperature. Transverse ridge can hold water from flowing away. High ridge can avoid the submergence of corn. Side deep fertilizing can supply abundant nutrient for maize seedlings, increase root length, and improve seedling growth. Most maize-growing regions in the Northeast China use small four-wheel tractors to clean stubble and ridge, and sow on the ridge with small seeders. As for the above model, the multiple field operations are needed, which always break the physical structure of soil, disturb soil layer and even lead to water consumption with low mechanical efficiency. The existing combined machines can not ridge and sow together, resulting in ridge damage and difficulties in row-follow. In terms of this problem, there is hardly combined equipment to fulfill the above tasks. In order to solve problems mentioned above, this paper designed 2BYMQF-4 maize stubble cleaning fertilization ridging seeder, which was suitable for the agronomic requirement (cleaning stubble, ridging, fertilizing and sowing in one time) in the Northeast China. By researching multiple ridging method, theoretical analysis of ridging and sowing was made by this paper. The multiple ridging method of this machine was divided into 5 steps: stubble cleaning and small ridging after rotary tillage; ditching, fertilizing and seed dropping; covering soil by double disks; hilling with ploughshare and compacting with broad width flexible compacting roll. This paper described the overall design of the machine, and determined the structure parameters and the working parameters of the main parts, such as the connecting mechanism, stubble cleaning device, sower unit and ridging device. The paper also described the working principles of the parallel quadrilateral adaptive connecting mechanism and the compensated suspension mechanism, as well as the mechanical structure and working principles of the precision planter unit, analyzed the stress under ideal condition by theoretical calculation, and made the finite element static force analysis of the ploughshare according to the calculation results. The paper calculated the power consumption of the track equipment and the power take-off shaft to analyze the power disposition, and analyzed longitudinal stability of the tractor mounted implement based on virtual prototype technology. According to this operation method, researchers made the test program and test method of maize stubble cleaning, ridging, fertilizing and seeding machine, and also carried out the field experiment on this machine based on the program and test method. Field experiment indicated that stubble crushing ratio reached 88.2% at the conventional working speed. The qualified rates of the ridging height, the width of ridging top and the distance between ridging rows were respectively 95%, 90% and 90%. The pass rate of average grain distance was over 92%, with the standard deviation of 43.65 and the coefficient of variation of 5.24. The average depths of seeds and fertilizer were respectively 56.22 and 114.36 mm, with the coefficients of variation of 10.07 and 10.28. The machine has the advantages of combined operation in maize stubble cleaning, ridging, fertilizing and seeding, such as simple operation, reasonable structure, safe and reliable work as well as high operation efficiency, which meets the design requirements. [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 farmlands in South Jiangsu province in China usually have characteristics of small acreage with fixed field boundary, balanced fertility inside one field plot and possibly significant fertility difference among different field plots even though some plots are close to each other. The reason for this phenomenon is that farmlands have been already assigned to rural families in small-scale-size plots for decades and the field plots are farmed by rural families independently. Rural families have a good understanding of overall soil fertility and yield potential about their own field plots, but they are not very clear about the matching relationship of target plant production and the needed amount of fertilizer for each field plot. According to the characteristics of farmland plots and the technical barriers of carrying out variable rate fertilization in South Jiangsu province, a simple executable scheme of variable rate fertilization was proposed in this paper. This scheme referred to a rough production-fertilization relation model which was established based on the "target output and fertilizer amount" theory by local government's agricultural departments in South Jiangsu Province. The final scheme for variable rate of fertilizer application is based on yield potential and target production data of the field plots. Using this scheme, the soil fertility of the field plots were classified into different grades. The target production of the field plots were discretized into finite data sets which were corresponding to different target amount of fertilizer application. Implementing this scheme for variable rate of fertilizer application was expected to obtain these effects: uniform application of fertilizer inside one field plot and adjusting the amount of fertilizer application to meet the actual needs of different field plots. The fertilizer-seeder machine for variable rate application, which was equipped with an electronic prescription map system based on the scheme of variable rate fertilization, was renovated from a mechanical sowing machine into an automatically operating system. The renovated system has the ability to automatically sense the working place site and the forward speed in field, and automatically adjusts the flow rate of the seeders with the help from the electronic prescription map system. With single crop field plot which has naturally-formatted boundary as a basic processing unit, the variable rate fertilizer-seeder which was equipped with an electronic prescription map system has the function as following: automatically mixing various fertilizers together as needs, uniform application of fertilizer inside a natural field plot and variable rate fertilization among different natural field plots. In order to further improve the precision quality and working stability. The data from the ordinary precision GPS model were processed with the methods of differential treatment and Kalman-filtering, which can reduce the data fluctuation caused by noise signal. The structure of fertilizer seeder with outer slots was optimized, which can efficiently reduce the edge leakage of fertilizer seeder and improve the flow rate consistency of the fertilizer seeder. Field experiments results showed that the operating outcomes of the electronic prescription map system were correct, the variable rate fertilizer seeder had a stable working state, the biggest and averaged amount errors were correspondingly 3.91% and 2.09%, while the biggest and averaged dynamic errors were correspondingly 4.52% and 1.48%. The research results can be the reference for implementing variable rate fertilization in small-scaled fields in South Jiangsu province in China. [ABSTRACT FROM AUTHOR]

A new grooved-roller seed metering device is developed to overcome the breakage of seedling, obtain high sowing rate and raise seeding efficiency in present, and exercise the optimal design. Firstly, this paper introduces the main structure, the working principle and the related structural parameters of the device in detail. Seed metering device is a key component to realize mechanized cultivation of Pennisetum, which is divided into 2 types according to its working principle. One type is real-time cutting seed metering device and the other type is pre-cut seed metering device. Compared with real-time cutting metering device, pre-cut seed metering device has the advantages of high automation, no damage to seed and lower labor intensity, so it shows a good market prospect and is the main trend of the future development of the metering device. The grooved-roller seed metering device is one of pre-cut seed metering devices. In terms of the stem stress state of seeding process, the evaluation function of seeding smoothness with force angle of the stem as the target was derived. According to the function, opening width of the seed groove and depth of the seed groove were the main impact factors of the improved device’s seeding performance. Based on the compressive strength of the stem, the best size of seeding slot was deduced as 20 mm × 20 mm finally. The different morphology and difference of seed diameters are the main influence factors of the problem, and those are easy to cause the bud break. The smoothness and accuracy of seeding were improved by adding the elastic dunnages on the groove of the seeding drum. According to the evaluation function of seeding smoothness, the structure size of the dunnages was optimized as the side gasket thickness of 4 mm and the bottom gasket thickness of 8 mm. In order to study the effect of dunnages on the fluency, the model of grooved-roller seed metering device of the Pennisetum was established by using the dynamic simulation software ADAMS (automatic dynamic analysis of mechanical systems). The effect regularities of structural parameters and motion parameters on seed groove and dunnages were studied. The simulations showed that the new seed metering device could realize the orderly discharge of seeds, and obviously reduce the stress of small-diameter seed by using the plastic dunnages, ensuring the seed row stability and the adaptability of seed diameter. Then the real tests in the laboratory and field were undertaken to verify the conclusions of virtual tests. Bench test results showed that the gasket could improve the flow degree of the seed row to a certain extent, in which the roller speed fluctuation ratio was less than 10%, the roller torque fluctuation ratio was less than 400%, and the seeding rhythm fluctuation ratio was about 20%. The research further indicated that the quality of the seeding was not affected by the roller speed, and sometimes the faster speed would slightly improve the fluidity of the seeding. Because when the roller speed was faster, the time the stem entered the entry took shorter, which reduced the resistance of the seed row to a certain extent. The results indicated that the seed metering device can realize the seeding operation and the dunnages can effectively improve the seeding fluency. Field experiment indicated that the seeder was stable, and the qualified index was greater than 93.33%, the missing index was less than 4.1%, the multiple index was less than 2.5%, and the variance coefficient was13.63%. The indicators were in line with the planting requirements of giant grass. The research provides a theoretical reference for the design of grooved-roller seed metering device of Pennisetum and the technical reference for the related design of planting machine. [ABSTRACT FROM AUTHOR]

Plastic film mulching technique has been used widely in China because of its notable benefits such as raising soil temperature, inhibiting weed growth, promoting crop maturity and increasing production, especially in the field of cotton cultivation, almost all of them used plastic film mulching technique in XinJiang. Recycled waste plastic film and cotton straw, stubble and other trash were difficult to separate, this problem caused difficulty in reutilization of waste plastic film. A large number of recycled waste plastic films were buried or burned randomly in field which lead to secondary environment pollution. In order to separate the waste plastic film from cotton straw, stubble and other trash, realize recycling of waste plastic film and solve the problem of environment pollution results from waste plastic film at source. The movement state and trajectory of cotton straw, stubble and plastic film were simulated through building of wind field device, and suspension velocity of cotton straw, stubble and plastic film were measured in wind field. The mathematical model of separation conditions was established through analysis of stress condition of different materials in wind field and law of settling of different materials in air medium. High speed dynamic camera was used to observe the movement of the material in the wind field, the feasibility of the principle was verified. Based on results of researches above, a type of roller sieve waste plastic film and trash winnowing machine was designed. In this paper, the overall structure and working principle of the machine were introduced, the structure and size parameters of the key components of rotating sieve cylinder and the helix in rotating sieve cylinder were determined. In order to determine the relationship between the best separation effect with rotating sieve cylinder speed, the outlet velocity of wind pipe, and the material feed quantity, an orthogonal test with rotating sieve cylinder speed, the outlet velocity of wind pipe, and the material feed quantity as the experimental factors were carried out, the raw material composition after mechanical harvesting was analyzed as test condition. Primary and secondary order of plastic film rate in trash and rate of trash in plastic film were confirmed through analysis of test results. Reasons of change were analyzed, and significance tests were done for factors of plastic film rate in trash and rate of trash in plastic film. Finally, the optimal parameter combination was determined. The results proved that when the rotating sieve cylinder speed was 30 r/min, the outlet velocity of wind pipe was 15 m/s, and the material feed quantity was 250 kg/h, the operation effect was best, the rate of trash in plastic film was the least, the plastic film rate in trash was minimum, the waste plastic film production was maximum. The machine was adjusted to the best working parameters for conducting production test and verifying the foregoing conclusion. The results showed that all indexes were met the design requirements, the rate of trash in plastic film was 13.71%, the plastic film rate in trash was 0.133%, the production of waste plastic film upped to 35.8 kg/h after separating. In summary, we designed roller sieve waste plastic film and trash winnowing machine, it can realized separation of waste plastic film from cotton straw, stubble and other trash effectively. This research fills gaps in this area in China. The secondary pollution causes by waste plastic film recycling can be reduced if the machined used, the utilization rate of waste plastic film can be improved greatly. [ABSTRACT FROM AUTHOR]

Due to lack of weed identification and positioning equipment，farmers usually use large area uniform spraying of chemical herbicides, which not only wastes herbicides and labor, but also leads to ecological environment pollution and agricultural product quality problem. At the same time, the weed control accuracy using existing mechanical weed control method is low with a high crop injury rate. Therefore, accurate weed identification is a key issue in target pesticide application and mechanical weed control. There are three kinds of weed identification method: image-based weed identification method, spectrum-based weed identification method, and spectral-image-based weed identification method. At present, spectrum sensor based on spectrum analysis has been most widely accepted in actual weed control due to its advantages of simple system configuration, lossless and high processing speed. Based on the four characteristic wavelengths (595, 710, 755 and 950 nm) selected by the investigation of weeds in the winter rape field, in this paper, we presented our research on weed spectrum sensor. According to the principle of optical system and the actual operation requirements in field, the structure design scheme of the spectrum sensor was proposed, which consisted of five parts, active light source, convex lens, light filter, photocell, and signal conditioning device. As the field measurement results vulnerable to weather conditions, we used LED as an active light source. There were four optical channels (595, 710, 755 and 950 nm) and three active LED light sources in the spectrum sensor. A K9 lenticular lens with diameter of 16 mm and focal length of 16 mm was chosen. A narrow-band interference filter with a center wavelength of 595, 710, 755, 950 nm was applied, whose half-peak bandwidth is 10 nm and aperture is 16 mm. The size of the photocell is 2.65 mm × 2.65 mm. The convex lens, the light filter and the photocell were sequentially arranged in the optical channels in order to detect the spectral information. Signal processing circuits were developed to meet the reliable output signal amplification, filtering and other requirements without distortion. The spectral distance of the spectral sensor is 400-700 mm while the diameter of the field of view is 60-100 mm. After that, the spectral sensor was applied to do calibration test and experimental verification. The calibration test established four mathematical models between the four output results by intelligent spectral sensor and the four measuring results of FieldSpec®3 spectrometer. The determination coefficients of each model were 0.799, 0.812, 0.892, and 0.867. The results of the experimental verification showed that most of the relative errors were within 10%, indicating that the designed sensor could separate winter rape from weeds. Therefore, the spectrum sensor could make its contribution to the exploration of weed automatic identification equipment. Experiments on actual weed identification showed that the average recognition rate was 90.7%, which had a good weed recognition effect. The main factors affecting the recognition results were the nature light and the mechanism vibration. How to reduce the influence of interference factors on the recognition precision will be the focus of the next research. [ABSTRACT FROM AUTHOR]

Corn parameters measuring are an important step in corn breeding. Currently, researchers measure corn parameters manually or with the help of machine vision technology. The existing corn parameters measuring and methods mainly aim at corn ears or kernels rather than measuring them at the same time, which is difficult to meet the demand of rapidly measuring a large amount of breeding materials in the breeding process. To solve this problem, in this paper, a high throughput automatic measuring device for corn was designed and a prototype was developed. This device mainly included corn ear parameter measuring unit, automatic threshing unit, corn kernels parameter measuring unit, post-processing unit, and system control unit, which can realize the whole process such as ear parameters measuring, ear threshing, kernel parameters measuring, kernel lifting, kernel packaging and label printing automatically. A weighting sensor and four high-resolution color cameras were evenly distributed around the ear with the interval of 90 degrees to get the corn ear images in four directions to acquire corn ear parameters such as ear weight, ear length, ear width, ear rows, bare tip, et al. at the corn ear parameter measuring unit. The average measurement accuracy for ear length and ear width was up to 99.13% and 99.21%. The Canadian Agriculex SCS-2 single ear corn thresher was chosen for automatic threshing unit. Efficiency of the thresher was up to 3-5 s/ear, which can meet the acquirements of high throughput processing. Corn kernels parameters such as kernel number, kernel average length, average width, kernel shape, et al. were obtained in corn kernel parameters measuring unit, which was designed and had three parts: (1) image acquisition device used for kernel images acquisition; (2) automatic spreading mechanism used for reducing kernel adhesion and accumulation, so as to obtain high-quality kernel images; and (3) kernel discharging mechanism used for ensuring the smooth implementation of high-throughput assembly line operation and letting the kernels discharged. The average accuracy of kernel number reached 99.39%. Post-processing unit can lift kernels from corn kernels parameter measuring unit to a fixed height and pack it with a printed QR code label which contained all corn ear and corn kernel parameters. A Kunluntongtai TPC7062K industrial control tablet and MODBUS relay control input-output module with 16 photoelectric isolating switch input channels and 16 photoelectric isolating relay output channels were chosen for the system control unit to receive sensing information and feedback to control the device. The results of experiment showed that the prototype can obtain information both for corn ear and corn kernels automatically. The average time consuming of the prototype for single corn processing was about 27.2 s, and the average efficiency was up to 4 ear/minute during continuous operation mode, which greatly improved the efficiency of corn breeding processes. [ABSTRACT FROM AUTHOR]

Currently, cultivated area of facilities horticulture is growing rapidly in China, while the level of mechanization is very low, and the production of hydroponic leafy vegetables during the seedlings transplanting is mainly manual. So it is needed to develop a plug tray seedlings transplanting machine which fits the mode of China's hydroponics leafy vegetables production. The main operation object of the current transplanting machine in facilities horticulture is potted flowers that use different culture-substrate comparing with hydroponics leafy vegetables. In contrast, the production of hydroponics leafy vegetables uses coco-peat as the main culture-substrate in the South of China. Coco-peat has characteristics of small bulk density, large porosity, poor water-retention capacity, and poor adhesion between particles. Therefore, the existing facility horticultural transplanting manipulators are not suitable for such substrate. In view of the above problems, a 4-needle-type transplanting manipulator for hydroponics leafy vegetables for coco-peat substrate was designed in this paper. In the transplanting manipulator, we used a non-shrinkable needle structure that depended on the angle of the telescopic needle which can reduce the disturbance of the coco-peat as well as avoided the spallation of the substrate cube. In order to compare the adhesion characteristics between coco-peat and peat moss, a cube compression test has been done. The test results showed that coco-peat was more likely to be scattered than peat moss because the coco-peat has the characteristics of large porosity and difficulty forming adhesion between particles, and this trend was intensified with the increasing of substrate moisture content. The percentage of scattered substrate mass in the transplanting process and the remaining component on seedling root growth needed to be evaluated. As such, a comprehensive evaluation method that the percentage of scattered substrate mass combined with scored scattered area was proposed in this study. An experiment was carried out that used hydroponics leafy vegetables of kale (Brassica oleracea) seedlings as transplanting target, and the plug tray for seedlings cultivation was a 50 (5×10) standard plug tray, the culture-substrates were coco-peat, peat moss and perlite with mass ratio of 8:2:1. Through the design and experiment study, the structure parameters of 4-needle-type transplant manipulator were as follow, telescopic needle diameter, 2.5 mm, the angle that telescopic needles insert into the substrate cube, 76°, the distance from the insert point of telescopic needles to the substrate cube edge, 5 mm. The results indicated that the root situations of hydroponics leafy vegetables seedlings had the greatest effects on the transplanting success rate, and the movement accelerations of the robot manipulator also had influences. The success rate of kale seedling transplantation was 100% , under the condition that the seedlings was in the status of normal growth, the vertical acceleration was 0.3 m/s2, the horizontal acceleration was 1.5 m/s2 and the substrate moisture content was 81.01%. This study provides a technical reference for developing transplanting manipulator which transplanted the hydroponics leafy vegetables seedlings that use coco-peat as the main culture substrate. [ABSTRACT FROM AUTHOR]

In order to solve the difficulties of sowing for foxtail millet and improve the low germination rate of millet after sowing in dry land of North China, we firstly studied the agricultural requirements of precision drill of millet without thinning out seedlings. We prepared a mixed suspension of foxtail millet using water and agricultural super absorbent polymers, because the agricultural super absorbent polymers can promote crop growth. We did some experiments to find suitable super absorbent polymers and the optimal proportion for mixed suspension according to the requirement of fluid seeding. At the same time we designed a kind of seed metering device by small-amount liquid for foxtail millet. This paper determined the number of rollers, dimension parameter and combination form of tube. It also expounded sucking seeds, delivering seeds and metering seeds of this seed metering device. This device consists of seed box, delivery pump, pump tube, three-way tube, long bent tube, end drainage tube and short bent tube. The function of delivery pump is providing power for the seed metering device, the function of three-way tube is dividing and combining the mixed suspension, the long bent tube or the short bent tube can improve the uniformity of seeding, and the end drainage tube can decrease every drop volume of mixed suspension to ensure that every drop has 2-3 seeds. Because the delivery pump has impulsive motion, we greatly reduced the impulsive motion of this device by using 6 rollers of .delivery pump and designing the structural style of tube, which has long bent tube, short bent tube, three-way tube and end drainage tube. The length of long bent tube is 100 mm, and the length of short bent tube is 74.4 mm. We also chose the material and diameter of tube. The material of tube is silica gel, which has the advantages of good elasticity and long service life. The diameter of pump tube, long bent tube, short bent tube and end drainage tube is 4.8, 4, 4 and 4 mm, respectively. Finally we designed and conducted the experiments of the uniformity and steadiness for mixed suspension of millet, and the variability coefficient of seed number was adopted. And we performed the performance tests with 4 indices adopted, including the percentage of damaged seeds, qualified rate of hill distance, qualified rate of seed number per hill, and rate of no seed hill for seed metering device in laboratory. We also carried out the field experiment of sowing with 3 indices including the qualified rate of hill distance, qualified rate of plant number per hill and seedling emergence rate for this device. The results showed that the suitable agricultural super absorbent polymer was Anxin for preparing the mixed suspension of foxtail millet, and the quality ratio of super absorbent polymers, grain of millet seed and water was 1.1 : 10 : 200 in mixed suspension; the variability coefficient of seed number was 9.8% in this mixed suspension, and was 9.7%-10.4% within 5 hours, and the seeds in mixed suspension had no obvious settlement. The percentage of damaged seeds was less than 0.01%, the qualified rate of hill distance was greater than 86%, the qualified rate of seed number per hill was greater than 75%, and the rate of no seed hill was less than 4% in laboratory test. The qualified rate of hill distance was greater than 77%, the qualified rate of plant number per hill was greater than 74%, and the seedling emergence rate was greater than 87% in field experiment of sowing. The results provide a theoretical reference for the design and analysis of seed metering device by small-amount liquid for small grain seeds. [ABSTRACT FROM AUTHOR]

The liquid quantity data is one of the most important information to spraying UAV (unmanned aerial vehicle). During the aerial spraying, the liquid quantity in the pesticide tank is dynamic, the operators have always to paid attention to the liquid quantity so that they can make suitable decisions for the flight controlling. Therefore, the liquid quantity monitoring method for pesticide tank is the most important in UAV spraying operation. However, other special characteristics need to be evaluated in order to achieve real-time monitoring the amount of pesticide liquid of spraying UAV, including unstable liquid surface, variation of physical and chemical properties of different pesticides, shapes of different tanks, the anti-corrosion requirements, tank sizes, etc. In this paper, we aimed to explore the feasible method for liquid quantity monitoring of pesticide tank in spraying UAV. Based on the above characteristics, we developed a solution called dual-pressure liquid quantity monitoring system, which consisted of double pressure sensors for liquid-level monitor, wave filter for liquid level turbulence (i.e.va combination of the median filter and the moving average filter), liquid level correction for aircraft on a tilt (based on a gyroscope), and conversion model for liquid level and liquid quantity. In order to verify the feasibility of the proposed method, a prototype of liquid monitoring device was developed, and the relevant verification test was conducted to test its performance. The experimental results showed that there was a significant (p < 0.05) linear negative correlation between the liquid level and pressure difference (between ambient atmospheric pressure and sealed air chamber pressure caused by liquid level), and the correlation coefficient R2 was 0.9989. It showed that the dual-pressure method can effectively eliminate the influence of ambient atmospheric pressure changes on the measurement accuracy and stability. By using the proposed wave filter, the C.V. (coefficient of variation) of liquid level data decreased from 28.45% to 12.27%, indicating that the proposed wave filter can filter off the liquid level turbulence effectively. By using liquid-level correction for aircraft on a tilt, the error was reduced to 0.05 from -1.09 hPa when the aircraft tilt up to 30°. Therefore, the proposed tilt correction method can effectively eliminate the error caused by aircraft body tilt. In order to test the performance of prototype of liquid quantity monitor in the actual spraying operation, the test based on a spraying UAV, 3WDM4-10, was conducted. The test included three different flying attitudes, forward, backward and turn around at the edge of field. When the payload of the pesticide tank was 2, 4 and 6 L, the mean liquid quantity data out by the liquid quantity monitor were 1.985, 3.942, and 5.984 L, the relative errors of the liquid quantity monitor were 0.75 %、1.45%、0.77%, the RMS error was 0.182, 0.199 and 0.180 L, respectively. The results demonstrated that the output of the proposed liquid quantity monitor is stable and reliable in different flying attitude. [ABSTRACT FROM AUTHOR]

In order to better realize the combination of agricultural machinery and agronomy, the design of precision rice hill-drop drilling machine was further optimized and tested. The precision rice hill-drop drilling machine that was powered with high speed transplanter chassis was composed of frame, furrowing and ridging device, height and horizontal profiling mechanism system, power transmission system, seeding device and hydraulic lifting frame. It could meet the rice direct seeding agronomic requirements which are furrowing and ridging synchronously, adjustable sowing rate and hill space, optional row space, profiling seeding mode and stubble burying before seeding. The combined hole-type metering device included small and big type holes was used for the precision rice hill-drop drilling machine, so that it could meet the sowing rate requirement of conventional rice and hybrid rice simultaneously and adjust the seeding rate quickly. On the basis of the combination of agricultural machinery and agronomy as well as the experimental verification, the frame, reduction gearbox, horizontal profiling mechanism, height profiling system and installation angle of slide plate were optimized. The new frame could protect the main bar from being bended. The new reduction gearbox made the hill space to match the speed of the chassis more accurately and also could change the rotation direction to fit different kinds of chassis. The height and horizontal profiling mechanism made the seeding machine more floatable, so it could adapt more complicate ground. Furthermore, the related experiments proved that profiling system is conducive to the seedling emergence of rice. The seedling emergence rates of the rice varieties XS134 and PZTF, which were seeded by the precision rice hill-drop machine with horizontal profiling mechanism, were 7.8% and 8.7% higher than that without horizontal profiling mechanism, respectively. In order to protect the atmosphere environment, the government introduced the relevant policies and laws to prohibit the burning of straw, and promoted the comprehensive utilization of crop straw. Many farmers returned straw residue to field to improve soil fertility and reduce environmental pollution, but it could be more difficult for the direct seeding machine and rice transplanter working in the field as well. To overcome this difficulty, the stubble-burying seeding was studied. The angle of the slide board was confirmed as 4° by the experiment result, while the efficiency of stubble burying was 91.6% and the furrowing and ridging effect under 4° was relatively better than that under other degrees. In this paper, some verification tests involved the main technical indices of the seeding machine and its reliability. Results showed that, the pure work efficiency was 0.67 hm2/h, the qualified rate of hill space was up to 100%, the variable coefficient was as low as 2.5%, the qualified rate of the seeds number per hill reached 95% and the cavity rate was 0; furthermore, the variable coefficient of the consistency of seeding quantity per row and the stability of total seeding quantity were 3.8% and 1.5% respectively; after seeding with horizontal profiling mechanism, the height difference between the left and the right field surface was about 2.0 cm; more important, the average of assignment before first-time fault (MTTFF) was 30.4 hm2/h, and the validity reached up to 98.2%. Therefore, on the basis of these results which all meet the national standard and the requirements of the combination of agricultural machinery and agronomy, and the reduction gearbox makes the machine+ more universal. The performance of the optimized precision rice hill-drop drilling machine is reliable and has exciting application foreground. [ABSTRACT FROM AUTHOR]

Rice is the most important crop in China, which has the largest planting area, the highest per unit area yield and the most total output. The production scale of rice has important significance to the development of grain production safety. Solid ridge is important guarantee for irrigation and rice growth. It can improve the yield of grain crops and reduce the waste of water resources, which is conducive to the construction of standardized farmland in China. At present, the ridge are built still by manual labor in some regions. The ridge building by manual labor have some problems such as poor quality, long operation period, and repeated labor intensity. Ridging operation belongs to a part of tillage operation in the whole production process. With the development of paddy field mechanization, the paddy field machinery ridging technology has become the bottleneck problem for production. Paddy field mechanization ridging is constructed by agricultural machinery to meet the production requirements of rice irrigation and ridge technology. Some Chinese scientific research institutes and agricultural machinery enterprises have carried out researches and designed paddy field ridge machines. These machines take the soil on both sides through the plow or rotary blade and other parts, and compact soil to build ridge by double disc rolling, but they have shortcomings of heavy body, poor flexibility, high power consumption, and limits to the sampling position, which affect the follow-up planting and soil leveling operations. This kind of machine can not fully meet the actual production demands in China. In order to improve the quality and the efficiency of ridging operation in paddy field, and to reduce the labor intensity, the 1DSZ-350 type hanging unilateral rotary tillage compacting ridger was designed, in view of meeting the agronomic requirements of rice planting in the northeast region of China. The overall structure and working principle of the ridger were illustrated and analyzed. The structural design and the theoretical analysis were conducted for key components, such as partial traction hanging adaptive mechanism, rotary tillage ridging adjustable depth transmission assembly, rotary tillage soil- collecting roller assembly and compacting ridging circular assembly. To improve the working performance of ridger and to obtain the best operation parameters, the quadratic general rotary unitized design experiment was carried out with the forward speed and the rotational speed as the impact factors, and the average value of ridge density and the variation coefficient of ridge height as the response indices. Based on experimental data, a mathematical model was built by using the Design-expert 6.0.10 software, the experimental factors were optimized, and the best combination was achieved. Test results showed that the forward speed of the ridger was 1.33 km/h, the rotational speed was 525 r/min, and the average of ridge density was 2 160 kPa, the variation coefficient of ridge height was 4.01%. On the basis, the field test was carried out, and the test results showed that the ridger was characterized by its compact-sized reasonable structure and simple operation. And its ridge had good quality, which was solid and smooth and could meet the requirement of paddy field production. The research results in this paper can provide the theoretical basis and direction for the research of mechanical ridger and its key parts for paddy field. [ABSTRACT FROM AUTHOR]

The plastic film mulch has the function of increasing soil temperature and preserving moisture, and it also can suppress weeds and maintain soil structure. Because of these special physical and chemical properties, agricultural mulching is extensively applied to cotton and other crops. Xinjiang is currently the largest cotton planting region in China, and all cotton cultivation involves film mulching. However, because plastic film itself is difficult to degrade and without scientific management and recovery in long-term use, a large amount of residual plastic film is left in the fields after harvesting, which has caused serious pollution problem to both the soil and the ecological environment. The mechanical collection of the plastic mulch is one of the effective ways to resolve plastic mulch pollution at present. Therefore, it is significant and urgent to study the residual film recovery methods and operation machines. Many kinds of mulching residues recovery machines have been developed and used, but there are some problems with the machines such as bad adaptability, low recovery rate, poor work efficiency in removing the collected film, and plastic films being easy to wind in cotton straw chopping, which needs further improvement for the machines. With a view to solving the above problems, a new method of operation step by step was proposed, which could collect plastic film in strip at first and then recover it, and a cotton straw chopping and plastic film strip-collection combined machine was designed. The machine mainly consisted of suspension device, power transmission system, straw chopping device, straw conveying device, strip-collection device, stripping device, and so on. Compared with the existing cotton straw chopping and plastic film collection combined machines, the machine proposed in this paper was simplified and efficient. The machine adopted the way of throwing cotton stalk into a certain height and distance to create a condition to separate cotton stalk from the residual film. Moreover, because of the ground profile modeling, this machine could be adapted to complex operating environments and operating requirements, and had a good performance on the strip-collection ratio. It could not only realize the straw chopper returning and the straw separation with plastic film, but also collect plastic film in strip with one operation, which ensured that it was easy to recover plastic film and recycle it. Based on the underlying theory analysis and experimental study, its basic structure and main parameters were determined, and the rational kinematic relationship among the knife-roller speed, the forward speed of unit, and the speed of strip-collection device was obtained by experiments. Field trials were conducted in Manas County of Xinjiang. The experiment results showed that the working efficiency could reach 1.15 hm2/h, plastic film collection stripe ratio was 92.6%, the straw chopping qualification rate was 97.5%, and the film-straw separation ratio was 90.5%, when the machine operating speed was 5-7 km/h, the cutter shaft speed was 1 880 r/min, and the speed of strip-collection device was 150-160 r/min, which could satisfy not only the agricultural requirements but also national standards. The research results can provide a reference to solve the problem of plastic film pollution in cotton-growing areas of China. [ABSTRACT FROM AUTHOR]

Potato is the fourth staple food product in China, and Chinese potato planting area of 6.7 million hm2 ranks first worldwide in 2013. However, the mechanized potato seeding percentage in China is only 23%, which is limited by poor performance of potato planter. Cup-chain metering device is the most commonly used for potato planting, whereas it is troubled with high miss-seeding and re-seeding problems. To solve these problems, the simulation model of potato planter is firstly built, and this model is used to analyze potato seed movement during metering process; then a new type of metering device with double-deck seed tank is designed, and finally the parameters of seeding speed, seed cup diameter and seed filling height are optimized. 1) Potato planter simulation: Potato cup-chain metering planter is simulated based on the software of EDEM (enhanced discrete element method). On the one hand, Hertz-Mindlin non-sliding contact model between 2 seeds is built with the recovery coefficient of 0.3, static friction coefficient of 0.56 and dynamic friction coefficient of 0.15; on the other hand, the model between seed and seeder is built with the recovery coefficient of 0.52, static friction coefficient of 0.5 and dynamic friction coefficient of 0.1. 2) Potato seed movement analysis: During the metering process, movement is originated from only a small part of seeds instead of most of them that are immobile. The small part of moving seeds determine the seed charging performance. The major movement area of potato seed is around the chain presenting the shape of inverted cone, which contains 3 areas of high-efficiency charging area, low-efficiency charging area and no seed area. The seed charging performance is directly affected by the volume of high-efficiency charging area and the seed mobility. 3) Seed planter design: Aiming to enlarge high-efficiency charging area and enhance seed mobility, planter with double-deck seed tank is designed, which doubles the volume of high-efficiency charging area and enhance seed mobility. A planter test platform with double-deck seed tank is modified from a 1 220 type potato planter provided by Zhongji Meno Polytron Technology. 4) Performance evaluation and parameter optimization: 2 indicators are employed to evaluate the planter performance, including miss-seeding percentage and re-seeding percentage. The influence of seeding speed, seed cup diameter and seed filling height in the seed tank on seed charging performance is studied. Regression equation and multi-objective optimization method are employed for parameter optimization. In the Chinese national standard for potato planter, miss-seeding percentage is no more than 10% and re-seeding percentage is no more than 20%, the designed planter can operate at the seeding speed of 0.96 m/s to satisfy this national standard. To balance the planting performance, including miss-seeding percentage and re-seeding percentage, and planting efficiency of seeding speed, the parameters of seeding speed, seed cup diameter and seed filling height in the seed tank are optimized as 0.67 m/s, 48.6 mm and 0.28 m, respectively, showing the miss-seeding percentage of 3.8% and re-seeding percentage of 8.8%. This paper demonstrates the potential for a high-performance cup-chain metering device with double-deck seed tank for potato planting. [ABSTRACT FROM AUTHOR]

Wheat straw is widely used as a kind of inexpensive, abundant, easily available, and sustainable raw material. At the same time, large amounts of wheat straw have still been burned on farmland in China, and have not been timely and properly applied. The smoke and dust from burning have highly adverse impacts on the environment. Therefore, it is urgent to study the pretreatment technology that is green, environmentally friendly, cost-effective and sustainable. Wheat straw was processed by physical methods, and the obtained raw fibers of wheat straw fiber mulch film were further pretreated by physical methods. In order to explore the influence of pulping process parameters on the pulp properties of the pulped raw fibers wheat straw fiber mulch film and the excellent pulp can be used to produce wheat straw fiber mulch film, the influence law of process parameters on the objective function was studied experimentally in this study. In the experiment, the whole wheat straw was pulverized by a crusher and the raw fibers of wheat straw fiber mulch film were obtained by a self-made straw fibers preparation machine. Taking the soaking water temperature, soaking time, beating time, beating load, and pulp volume as influence factors and the dry tensile index, beating degree and pulp fiber length as response indexes to evaluate the pulp properties. The five-factor and five-level (1/2 type) quadratic regression orthogonal rotation center combination design parameter optimization test method was adopt. The variances were analyzed using Design-Expert V6.0.10, and regression models were established between response indexes and influence factors. The analysis results showed that the beating time and the beating load had a very significant effect on the dry tensile index (P<0.01), and the interaction of various factors has no significant effect on the dry tensile index (P>0.05); the beating time, beating load, and the pulp volume had a very significant effect on the degree of beating (P<0.01), the interaction of soaking water temperature and soaking time had a significant effect on the degree of beating (P<0.05) while the interaction of the soaking water temperature and the pulp volume had a very significant effect on the degree of beating (P<0.01 ); beating time and beating load had a very significant effect on fiber length (P<0.01). The regression model optimization results were the soaking water temperature 63℃, soaking time 2 h, water volume of pulping pool 13.50 L, pulping load 4.57-5.50 kg and pulping time 0.25-0.68 h. Under such an optimized combination conditions, the response indexes of wheat straw fiber mulch film pulp processed as follows: the dry tensile index was greater than 5 Nm/g, the beating degree was less than 50 °SR, and the pulp fiber length was more than 0.9 mm, which indicated that the processed pulp could be used for manufacturing wheat straw fiber mulch film, and the wheat straw fiber mulch film could meet the technical requirements for covering and cultivating crops in wet and dry fields. [ABSTRACT FROM AUTHOR]