Key Laboratory of Modern Agricultural Equipment

Nanjing, China

Key Laboratory of Modern Agricultural Equipment

Nanjing, China
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Zhang Y.H.,Southwest University | Yang L.,Southwest University | Li S.T.,Southwest University | Xie S.Y.,Southwest University | And 2 more authors.
INMATEH - Agricultural Engineering | Year: 2016

A mathematical model of scoop angle of the sidelong edge of a handheld tiller's rotary blade was established by plane conversion and angle change. The effects of cornerite of the sidelong edge and bending angle of the blade on scoop angle were studied as well. The results showed that: with increase of the cornerite, scoop angle linearly increases at large for sidelong edge of cornerite from 30.5 to 45.4°, the corresponding scoop angle increases from 66.6 to 76.6 ° for a position, of same cornerite (other parameters remain constant), on the sidelong edge, scoop angle increases with increase of bending angle.


Zhou J.,Nanjing Agricultural University | Zhou J.,Key Laboratory of Modern Agricultural Equipment | Hu C.,Nanjing Agricultural University
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2015

Global navigation satellite system for localization of agricultural machineries has been successfully used for many years in a broad-acre environment. However, it will fail to work in a close planting orchard because navigation satellite signals are often interfered by dense tree canopies. Moreover, localization by only odometers can lead to a large accumulated error. Therefore, firstly the position of an agricultural robot before entering inter-row of the close planting orchard was taken as an original point and a world coordinate system was established. A laser radar was applied to scan trunks on the both sides of the robot and the center points of trunks were extracted through circular clustering. The position values of these center points were saved in the world coordinate system. Then during the moving of the robot, the center points of trunks detected by the laser radar in real time were matched with those which had been saved previously in the world coordinate system. Matching results were applied to correct the robot position and heading angle which had been measured with only odometers. In this way the agriculture robot was able to locate itself accurately in the inter-row of the close planting orchard. Repeated experimental results showed that the robot localization standard errors in both x and y directions in the world coordinate system were about 0.08 m. The localization accuracy can meet requirements when the agricultural robot is applied in the close planting orchard. Moreover, the successful inter-row localization is the premise of global positioning and navigation of the robot working in the orchard. © 2015, Chinese Society of Agricultural Machinery. All right reserved.


Yu Z.,Nanjing Research Institute of Agricultural Mechanization | Yu Z.,Key Laboratory of Modern Agricultural Equipment | Hu Z.,Nanjing Research Institute of Agricultural Mechanization | Hu Z.,Key Laboratory of Modern Agricultural Equipment | And 8 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

In the present, the mechanized harvest technology of garlic in China is still in infancy. Most of the current domestic garlic harvesters only can accomplish the processes of digging and laying. However, the garlic combine harvester, which can synchronously finish the processes of digging, cleaning soil, cutting stem, cutting beard, gathering garlic bulb, etc., is still under test and demonstration. Furthermore, picking is the most important and difficult process of combine harvest, because the bad separation will result in another manual cutting. Different with the harvest mode of the developed countries, the farmers in China pull out the young garlic shoot in its early stage, which causes the garlic to collapse and affects its locating in the application of half feeding combine harvest. Besides, the residual stem is long, the damage rate is high and the cut pass rate is low. In view of the above problems, a picking device of garlic combine harvester was designed, realizing the garlic plant flexibly clamped, the garlic being sorted one by one and aligned automatically. In order to further study the garlic picking device, the garlic picking testbed was designed. The garlic picking testbed consists of a garlic picking device, shelf and transmission system. The main goal of testbed is the garlic picking device which consists of a clamping device, a rank-alignment device, a cutting device. In order to enhance operational performance of garlic picking device, reduce the residual stem length, the damage rate and increase cutting surface pass rate, the Box-Benhnken central composite experimental design principle was conducted in this paper. A four factors and three levels response surface experiment was completed on the garlic picking testbed, with four factors which affect picking quality. This paper established the response surface model and studied the factors affecting picking quality. At the same time, it synthetically optimized the factors affecting picking quality. The results showed that trial factors had great effects on picking quality. The significant effects of clamp number, main chain speed, clamp height, and clamp angle on residual stem length were in a decreasing order; The significant effects of main chain speed, clamp number, clamp height, and clamp angle on damage rate were in a decreasing order; The significant effects of main chain speed, clamp number, clamp height, and clamp angle on cut pass rate were in a decreasing order. The higher main chain speed, higher clamp height, more numbers of plants, then the residual stem length was longer, in contrast, the residual stem length was shorter. The higher main chain speed, shorter clamp height, more numbers of plants, then the damage rate was higher, in contrast, the damage rate was lower. The lower main chain speed, higher clamp height, less numbers of plants, then the cut pass rate was higher, in contrast, the cut pass rate was lower. The interaction of various factors affecting residual stem length, damage rate and cut pass rate were not significant changed. The optimum parameters were that the speed of main clamping chain was 1.05 m/s, the clamping angle was 77°, the clamping height was 220 mm, and the clamping number was two. The results have provided a base for the garlic picking mechanism. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.


Wang M.,China Agricultural University | Song J.,China Agricultural University | Liu C.,China Agricultural University | Liu C.,Key Laboratory of Modern Agricultural Equipment | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

In designing a picking seedling mechanism, it is important to see the compressive characteristic of plug seedlings. So, in this research, the experiments were designed and conducted to get the compressive characteristic of plug seedlings. For more details, in the experiments, 20 pepper plug seedlings with growth period of 40 d were selected randomly. These seedlings were measured, their average height was 140 mm, the average height of the pot was 44 mm, the width of seedlings' leaves was 109.8 mm and the diameter of the seedlings' stem was 2.47 mm. Crank-rocker type seedling clamping mechanism was designed according to corresponding requirements. This mechanism was driven by an adjustable-speed motor and a crank and the movement of the rocker clamper was designed as reciprocating swing. In cooperation with the ejection mechanism, the rocker clamper could capture the seedlings at the right place and move them to the target position. Then, the rocker clamper could accomplish the processing of planting by loosening the 2 plates of the clamper. Also, in this research, an experimental platform of a crank-rocker type seedling clamping mechanism was fabricated and manufactured and with this platform a series of experiments were conducted. In these experiments, 3 experimental factors were set as claw clipping force, clipping claw material and moisture content of plug seedlings. Each experimental factor contained 3 levels and success rate of clamping, expulsion rate of seedlings and broken rate of seedlings were set as 3 test indices. Experiments were repeated by 8 times for each distinct condition, and totally 216 experiments were conducted under 27 different conditions. This research analyzed the mechanical parameters of the crank-rocker type seedling clamping mechanism and the corresponding moisture levels of the seedlings which could lead to the best planting performance. Furthermore, besides the design of the main components of the crank-rocker type seedling clamping mechanism, this research also conducted the mechanical and kinematics analysis on the working process of this seedling clamping mechanism. Also, the movement simulation was conducted with the aid of the simulation software i.e. Solid works COSMOS Motion. In this approach, the structures and the main parameters of the mechanism were properly designed. For more details, the length of the crank, the connecting rod and the swinging rod was respectively designed as 80, 236.22 and 172.5 mm. The test results indicated that when the rocker clamper was metal, the stiffness coefficient was 90 N/m respectively, the expulsion rate and the broken rate of seedlings and the success rate of clamping were 0, 4.2% and 95.8% respectively which meant that the Crank-rocker type seedling clamping mechanism could match the desired performance. The test results showed that when the moisture content of plug seedlings was 60.8%, the plug seedlings had excellent adaptation to different stiffness coefficient and material of clamper, and the average success rate of clamping was 94.4% in this condition. This mechanism could take seedlings from the initial position and put them to the target position by using circular trajectory. The condition of opening and closing of the claw could be controlled by trapezoid track and reset spring. The design was simple and reliable. This mechanism could work with plug seedlings with various shapes and sizes without additional adjustment, and it also contained high adaptability to the seedlings with different moisture levels. Also, it would minimize the damage of the plug seedlings and significantly improved the efficiency of the process of seedling capture and planting. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.


Xiao D.,Key Laboratory of Modern Agricultural Equipment | Xiao D.,South China Agricultural University | Fu J.,South China Agricultural University | Deng X.,South China Agricultural University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

For bactrocera dorsalis field monitoring, the current method had some disadvantages: a heavy workload, low efficiency, poor reliability, low accuracy, and it could not large-scale and fast monitor the orchard pest situation in real time. Agriculture experts eager to have a solution to automatically count the number of bactrocera dorsalis and remotely observe the trapping result in real time to reduce their labor so that they could focus more on the study of the characteristics of insects. Therefore, combining the image target detection technology and the target tracking technology to develop an automated counting system by using a video image sensor would be necessary. In order to realize the real-time monitoring, the bactrocera dorsalis trapping, and a rapid diagnosis, an IOT-Based remote monitoring equipment for bactrocera dorsalis trapping was provided in this paper. The equipment included a trap monitoring device, a solar power supply device, and the monitoring control device. The trap monitoring device was comprised of a top cover, a transparent funnel, a trap bottle, a LED, and a camera; the solar energy device was comprised of a solar panel, a storage battery, and a solar panel bracket; the bactrocera dorsalis monitoring control system device was comprised of a Fit-pc controller, a 3G communication module, and the independent software for counting bactrocera dorsalis' numbers. This equipment combined machine vision technology and telecommunication technology with solar power technology. The purpose of the equipment was to achieve a whole function for bactrocera dorsalis trap monitoring with plant diseases and insect pests information collection, together with processing, transmission, and self-supply. It could monitor the trapping process and precise calculation of the number of bactrocera dorsalis anytime and anywhere, and also automatically transmit the results to the remote server or store it in a local storage card. For object extraction, this paper used an HSV color space for image filtering, then used median filtering and morphological filtering for the image to reduce white noise, eliminating holes in the target area to improve the image quality, and then divided the image into blocks based on the adjacent pixels of the image and used these blocks for Geometric feature matching, so that the bactrocera dorsalis area could be extracted. Finally, this paper used the watershed algorithm based on weight for an image segment to get the tracking object and tag the object. For bactrocera dorsalis tracking, this paper used a Kalman filter to predict the target movement position, narrowing the range of target searching and target matching, reducing the amount of calculation of the target matching; and established a cost model by using centroid Euclidean distance, survival time, and the color difference of the target between two consecutive frames; updated the cost model of each tracked target, and handled the missing target to ensure the stability and accuracy of the tracking algorithm. For bactrocera dorsalis metering, this paper studied a counting strategy for moving targets. This equipment was tested in the laboratory environment. There were 138 bactrocera dorsalis entered in the equipment in 830 s, the detected result of the system was 131, and the detection success rate was 94.9%. Also this equipment was tested in the Yangtao Park for more than a year (from November 2013 to December 2014), and the system hardware and software could work cooperatively and stably. The system stopped running only when there was a shortage of solar power, rendering it ineffective under grim weather for lack of the light. The IOT-Based remote monitoring equipment for bactrocera dorsalis trapping could automatically track and count the number of bactrocera dorsalis. It could also provide simple and effective monitoring information to the regional monitoring personnel, improve work efficiency, greatly improve the performance of the monitoring system, and had a wide range of applications in agriculture. This equipment had important practical applications. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.


Zhou L.,Key Laboratory of Modern Agricultural Equipment | Xue X.,Key Laboratory of Modern Agricultural Equipment | Kong W.,Key Laboratory of Modern Agricultural Equipment
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

The jet mixing apparatus (JMA) is a vitally important part for mixing water with a pesticide, including a working nozzle, suction inlet, diffuser, thumb lock, case, end cap, one-way ball, inserts, etc. The Jet Mixing Apparatus is a simple device with no moving parts, where a high velocity flow (water) is used to pump a second fluid (pesticide). It was broadly used in large plant protection machinery. Its main property is efficiency and stability of the mixing ratio. Cavitation is a physical phenomenon in a Jet Mixing Apparatus happening at low pressure, seriously affecting the performance and wasting energy. In order to acquire the characteristic curve of the relation on the mixing ratio and pressure ratio, experimental and numerical analyses were used to measure the mass flow rate of working, intake, and mixed fluid. The test was conducted in the Key Laboratory of Modern Agricultural Equipment in accordance with the JB/T9782-1999 general test method for plant protection machinery. The outlet pressure was regulated to different levels (0.25, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.35 MPa) by a throttle valve, an electronic scale for mass flow rate, a U mercury manometer for vacuum, which was at 2.0 MPa working pressure and normal atmosphere intake. The computational fluid dynamics (CFD) software ANSYS fluent 15.0 was used for numerical simulation of the cavitation. The Zwart-Gerber-Belamri cavitation model in mixture model was adopted to capture cavitation, and obtained the internal static pressure distribution and gas distribution contour under different outlet pressures. Water was set as the main phase, with density of 1000 kg/m3, and dynamic viscosity of 0.001 kg/(m∙s). Water vapor was set as the second phase, with density of 0.02558 kg/m3, dynamic viscosity of 1.26×10-6, and the bubble radius of 0.01 mm. Cavitation pressure was set 3 540 Pa. The two inlet boundary condition was set at pressure-inlet, turbulence intensity of 2%, and hydraulic diameter of 14 mm. The outlet boundary condition was set at pressure-outlet, turbulence intensity of 2%, and hydraulic diameter of 9 mm. A double precision solver and pressure velocity coupling algorithm was adopted. The pressure equation was discrete with two-order upwind, and other equations with the QUICK method. Calculation of residual was set for 10-6, using hybrid initialization to initialize. The experimental values and the simulated values were compared for fitting analysis, and the mathematical relationship between the experimental values and the simulated values was established. The fitting coefficient R2 was 0.9618, which verified the accuracy of the model. The results showed that JMA has poor performance even backflow when the pressure ratio was greater than 0.6. The static pressure on the central axis had no significant difference in a working nozzle at the different outlet pressures, negative pressure appeared at the nozzle exit, and the negative pressure zone increased with the decrease of the pressure ratio. The mixing ratio was negatively correlated with the pressure ratio when the pressure was between 0.4 to 0.6. The mixing ratio and pressure ratio were independent when the pressure ratio was less than 0.4, which was the cavitation mixing ratio. The cavitation happened at the outlet pressure of 0.8 MPa, and the lower the outlet pressure, the more severe the cavitation, which was under working pressure 2.0 MPa, and suction pressure zero. Numerical and experiment research of cavitation is a meaningful area for research for improving the efficiency of a jet mixing apparatus. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.


Xiao D.,Key Laboratory of Modern Agricultural Equipment | Xiao D.,South China Agricultural University | Huang S.,South China Agricultural University | Yin J.,South China Agricultural University | Feng J.,South China Agricultural University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

Embedded intelligent vision sensor technology has become a research hotspot of wireless vision sensor network (WVSN) due to its low cost and high efficiency image capturing. In earlier research, a low cost and high resolution agricultural vision sensor (HRAVS) was developed based on the platform S3C6410 and OV3640 in South China Agricultural University. In this paper, a vision sensor remote transmission control schema (VSRTC) was developed to enable HRAVS to communicate with each other in various communication technologies (cable, 3G, 4G and Wi-Fi). The combination of HRAVS and VSRTC can be applied in many areas of the Internet of Things (IOT) in Agriculture. This paper introduced design of application architecture, transmission control protocol, and the node's application software of the VSRTC-HRAVS. A WVSN test was conducted for 25 days with 10 camera nodes in experimental fields of South China Agricultural University. Node control stability, the image capturing and encoding performance, the overall average image capturing time and the average frame rate of video capturing under different resolutions were evaluated in a series tests. The results showed that the new camera nodes were able to effectively carry out 3 capture modes (command response/cycle response/video), and under the re-transmission mode, the instruction loss rate was below 1% of all nodes. Given image pixel of 1.3, 2.0 and 3.2 Mpixel, when running without networking, the shortest average overall image processing time of the node were 6.2, 8.2 and 11.1 s respectively, and the largest video frame rates were 58.7, 34.6 and 16.4 frames per second, respectively; When running networking, the shortest average overall image processing time of the node were 17.6, 26.9 and 49.6 s respectively, and the highest video frame rates were 20.2, 16.1 and 9.3 frames per second, respectively. This scheme supported high resolution image and video transmission which can be applied in the field of agriculture where real-time transmission is not highly demanded. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.


Lu X.L.,Key Laboratory of Modern Agricultural Equipment | Lu X.L.,Chuzhou University | Hu Z.C.,Nanjing Research Institute for Agricultural Mechanization | Peng B.L.,Nanjing Research Institute for Agricultural Mechanization
Applied Mechanics and Materials | Year: 2014

Picking peanuts is the key operational link and the core technology of peanut combine harvester. On the basis the theoretical analysis of picking mechanism and structural parameters of the half-feed picking roller, and combined with the picking performance experimental, the structural parameters of the picking blades and blades quantity of picking roller were studied. The results show that: when the straight-shaped blade is picking, the picking force is strong, the broken branch and seedling phenomenon is serious, peanut broken rate and peanut with handle rate are higher; the arc-shaped blade reduced peanut damage, and effectively reduced the rate of the peanut with handle. The picking blade radian has a large impact to the peanut broken and loss rate. When the blade radian is 70° and the blade radius is 35mm, total loss rate is the lowest on the picking segment of the blade. The blade quantity has significant influence to the peanut broken and loss rate. The peanut broken rate of the 8 blades is 2 to 3 times of the 4 and 6 blades; the picking net rate of the 4 blades is much lower than 6 and 8 blades. The self-design the picking roller is 6 arc-shaped blades, the blade radius is 35mm, and the blade radian is 70°. The study provides the design basis for the research and development of the half-feed peanut picking device. © (2014) Trans Tech Publications, Switzerland.


Lu X.L.,Key Laboratory of Modern Agricultural Equipment | Lu X.L.,Chuzhou University | Hu Z.C.,Nanjing Research Institute for Agricultural Mechanization | Peng B.L.,Nanjing Research Institute for Agricultural Mechanization | Yu Z.Y.,Nanjing Research Institute for Agricultural Mechanization
Computing, Control, Information and Education Engineering - Proceedings of the 2015 2nd International Conference on Computer, Intelligent and Education Technology, CICET 2015 | Year: 2015

In order to improve the working performance of half-feed picking device, the components’ collocation relationship and picking process were studied. The composition and working principle of picking device were introduced. The configuration relationships in between the components were studied. These were analyzed on the motion characteristics and hitting force of the blade, and the influences factors and rules of the effecting picking frequency. The analysis results shown: the configuration mode of the roller and clamping conveyor chain adopt the oblique configuration, and picking roller adopts gradually tight angle and differential phase configuration mode, which can effectively increase picking space, avoid missing picking, reduced the damage rates and power consumption. These factors were comprehensive influences to the picking performance of the roller rotational speed n, picking roller length Lz, the angle between roller δ, roller diameter D and clamping conveyor speed v. The greater the roller rotating speed is, the stronger the blade hitting and combbrush role is, the greater the influence of the clamping conveyor chain speed is, the higher the picking net rate is, but the greater the damage rate of pod is and the higher the impurity rate is; with the increase of the roller turning angle, the hitting force is reduced, comb-brush role is enhanced, the picking net rate and damage rate are decreased, the influence of the clamping conveyor chain speed is decreased too; the bigger the level deflection angle of the picking roller is, the greater the axial hitting force is, the smaller the radial hitting force is, and the greater the influence of the clamping conveyor chain speed to picking quality is. When the Lz decreased and δ increased, the picking time of the peanut region will shorten, it directly reduces the picking frequency, and then the picking quality has affected. The study provides a theoretical basis and technical reference for research and development of the half-feed peanut picking device. © 2015 Taylor & Francis Group, London.

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