To protect crops from diseases and increase yields, chemical agents are applied by boom sprayers. To achieve the optimal effect, the boom and the crop canopy should be kept at an appropriate distance. So, it is crucial to be able to distinguish the crop canopy from other plant leaves. Based on ultrasonic ranging, this paper adopts the fuzzy iterative self-organizing data analysis technique algorithm to identify the canopy location. According to the structural characteristics of the crop canopy, based on fuzzy clustering, the algorithm can dynamically adjust the number and center of clusters so as to get the optimal results. Therefore, the distances from the sensor to the canopy or the ground can be accurately acquired, and the influence of lower leaves on the measurement results can be alleviated. Potted corn plants from the 3-leaf stage to the 6-leaf stage were tested on an experiment bench. The results showed that the calculated distances from the sensor to the canopy using this method had good correlation with the manually measured distances. The maximum error of calculated values appeared at the 3-leaf stage. With the growth of plants, the error of calculated values decreased. The increased sensor moving speeds led to increased error due to the reduced data points. From the 3-leaf stage to the 5-leaf stage, the distances from the sensor to the ground can also be obtained at the same time. The method proposed in this paper provides a practical resolution to localize the canopy for adjusting the height of sprayer boom.

虚拟植物是现代数字化农业和精准农业核心部分之一,在计算机、农业、林业、教学等领域应用前景广阔.根据研究策略和研究难点不同将研究对象分为地表上植物模型和根系模型2个部分.针对地表上植物(茎叶系统)模型,在阅读大量国内外文献的基础上,按研究尺度不同将各学者研究成果分为植物整体形态模拟、植物器官三维建模、植物生长过程模拟、植物结构-功能并行模拟四大类,并分别综述其研究现状;针对根系模型,从农业角度出发,综述常见农作物根系生理生态模型的研究进展.综合以上植物模型的研究方法,对虚拟植物建模方法进行总结分析.最后简述了虚拟植物研究重点与难点并对其发展趋势进行展望.

The spray boom in the plant protection machinery are more accustomed to use multi- hydraulic cylinders to control the expansion and folding in China, which results in the problems of asynchronous operation, poor stability of the spray boom and high production cost. So a combination mechanism of single cylinder and guyed flexible shaft that mainly consist of reverse double angle rotary folding mechanism and mobile expansion angle mechanism was designed to control the spray rod. The study on the working principle of reverse double angle rotary folding mechanism and interference phenomenon was to reduce the overall quality of the spray rod for the optimal design of reverse double angle rotary folding mechanism. At the same time the working principle of the mobile expansion angle mechanism and the movement process were studied. The mathematical model of flexible shaft mounting position was established to research the movement by vector method. In order to find the optimal location for cable shaft installation, an orthogonal design for three factors and four levels was carried out by using the position (x, y, R) as the test factors and the stability as test indicators. Then the virtual prototype model of spray bar mechanism was set up on Solidworks, and the motion characteristics and mechanical properties of spray rod were analyzed in detail. The results showed that the optimal combination of the guyed flexible shaft installation was x=300 mm, y=-50 mm, R=200 mm, at this time, the boom stability was 0.19, and the motion stability was the best. At the same time, the virtual simulation test showed that the angular velocity range of the big arm and the small arm of the sprayer was 6rad?s-1to 13rad?s-1, and the numerical solution was accordance. The initial velocity of the sprayed rod and the large arm was 585 mm?s-1and 185 mm?s-1, respectively. The speed of the sprayed rod was about 3 times the speed of the large arm and the law of velocity change was the same in motion. The spray rod arm relative big arm angular displacement was linearly distributed in the range of -180°-0°, the force of the motor was uniform, the torque spring torque was changed to 1620 N?mm-1, the mechanism follows the law of conservation of energy and its optimal motion stability was obtained. The correctness of the theoretical analysis of the relative displacement of the Sprayer arm and the vector method for calculating the installation position of the soft shaft of the drawing line was verified, which indicates the correctness of the design of the mechanism. These results could provide a necessary reference for the design of folding large width boom sprayer with simple structure, small overall quality and convenient control.

Aiming at the design and manufacture difficulty of stubble-cutting disc with oblique ripples, taking one made by America as research object, a kind of computer aided design method was proposed, which was fulfilled in the basis of the structural parameters that were obtained through reverse engineering technology.The point cloud data were obtained by using a Digital Structure Light 3D scanner and a binocular stereoscopic vision system, then the structural equation and parameters was acquired by fitting the data of feature points extracted from the point clouds through boundary detected and curvature calculation.On this basis, 3D parametric model of the stubble-cutting disc with oblique ripples was created in a computer aided design system of Solidworks, which will provide a foundation for its engineering analysis, parameter optimization and mould manufacture.At the same time, this work broadens the range of application of reversing engineering, and also will provide references for researching the application of reverse engineering in the design and manufacture of agricultural machinery.

整机结构形式、操控方式等要素是影响大幅度喷杆式喷雾机整机性能的主要因素.为此,通过查阅文献,从喷杆基本结构形式和喷杆式喷雾机控制及调整方式两方面来综述大幅度喷杆式喷雾机的结构形式,分析不同结构形式喷雾机的性能特点及操控的方便性等.通过查阅资料及综合分析,钢结构桁架结构是目前大幅度喷杆式喷雾机主要结构形式.在操控方面,主要以液压折叠为主,个别型号机械能实现半自动或手动高度调节,能进行喷杆仰角的调整机械国内还鲜见报道.

The development of the potato into staple food has become an inevitable trend, so more and more attention has been paid to the potential benefits of potato. Potato harvesting mechanization and potato product refinement are inevitable trends in the process of developing potato. The size and shape of potato tubers are important parameter used for the classification of potatoes, and the number of potatoes per plant and its distribution range are influential basis for designing the potato harvesting machinery. Therefore the study of potato's physical parameters is very necessary. In this study, 5 kinds of early maturing potato varieties were selected, including ZaoDabai, Eugene, FuJin, Holland fifteen and Favorite. These varieties are common planted in Northeast China. Fifty potato plants were randomly selected from each variety for physical parameters test, statistics and analysis. The objectives of this paper are to measure the tuber distribution range and count the number of tubers of each potato plant, to measure the maximum horizontal distance between tubers, marked as lateral spacing, to measure the distance between the deepest tuber and ground, marked as longitudinal spacing, to gauge the tubers' shape and size based on visual technology. The main methods are as follows: Design of an image acquisition system. Acquiring an image using the mirror while three directions of potato will be included. Based on calibration block's relationship between Pixel value and actual size, the actual size of the potato's longest diameter was obtained. The shape of potatoes are obtained by the function of minbroundrect. Later in this article,variance analysis was used to analyze whether there were significant differences in the physical parameters of diverse potato varieties. The results are shown in the diagram. Through the above methods, four conclusions are obtained. Firstly, different varieties of potatoes have the same tubers width distribution B1, mainly concentrated in the 20-30 cm, but their tubers depth distribution D0 have significant difference (p<0.05), both Zaodabai, Holland fifteen and Favorite mainly distributed in 14-16 cm, and FuJin mainly distributed in 16-18 cm; Eugene mainly distributed in 18-20 cm. Secondly,different varieties of potatoes have the different quantity of tubers, after the Variance analysis, there is a significant difference (p<0.05), the average number of tubers per plant of ZaoDabai is 3.6, more concentrated in 3-5, accounting for 80% of the total. The average number of tubers per plant of Favorite is 4.7, more concentrated in 4-6, accounting for 88% of the total. The average number of tubers per plant of Holland fifteen is 4.9, more concentrated in 4-6, accounting for 84% of the total. The average number of tubers per plant of Eugene is 6.2, more concentrated in 5-7, accounting for 76% of the total. The average number of tubers per plant of FuJin is 7.5, more concentrated in 7-9, accounting for 66% of the total. Thirdly, Eugene' shape is in large part of ellipsoid, accounted for 83.37% of the total number of tubers. Tubers' shape of ZaoDabai and FuJin are mainly ellipsoid and round-likely roundness, accounted for 72.22%, 19.44%(Zaodabai) and 77.33%, 22.67% (Fujin) of the total number of tubers, respectively. Tubers' shape of Holland fifteen and Favorite are mostly ellipsoid and long bar, accounted for 24.49%, 75.15%(Holland fifteen) and 19.15%, 74.47%(Favorite) of the total number of tubers, respectively. Finally, tubers' size of FuJin, ZaoDabai and Eugene are mainly distributed in 50-80 mm, 60-100mm and 50-120 mm, respectively. The size's distribution of Holland fifteen and Favorite is more dispersed, potatoes with the diameter above 120 mm accounted for 10.20% and 12.76%, respectively. The results provide theoretical basis for the design of the digging components of potato's harvest, and provide the gauge for further study on the three-dimensional model of potato tuber-root system.

The structure design that only by traditional statics calculating procedure for large amusement equipment is not accurate. It must be combined with the kinetic parameters to find the most dangerous working conditions, and then make optimization design for meet safety standards. This paper is studied by taking “self-control plane” amusement equipment cantilever beam as the research object, using the rigid body dynamics analysis function of SolidWorks - Motion based on virtual prototype technology. The simulation analysis for the performance of the rigid body dynamics were carried out on the three different working conditions in the process of equipment operation, which achieved by the dynamic analysis model, the forms of motion and load setting in SolidWorks. The stress curve of key parts of cantilever beam were got under different working conditions, and its maximum loads were found out at direction of X,Y,Z. The simulation results showed that its maximum stress location was the joint of the hydraulic cylinder and cantilever beam. The study would offer necessary data guidance for beam structure refinement design basis and provide theoretical and technological support for design of relative cantilever beam.

大型设备的结构设计,必须依据最恶劣工况条件下的动力学参数进行分析.以大型回转游乐设备(海盗船)为例,在SolidWorks平台下利用Motion模块,对设备的刚体动力学特性进行分析.探讨一种在一个平台下,快速完成结构设计与虚拟样机分析新方法.该方法可以在初始设计阶段,可以实现同一实体模型完成结构参数设计与刚体动力学分析等多项任务,不需要进行模型转化等工作,简化设计过程,提升设计的自动化水平,同时帮助设计人员在设计前期判断设计能否达到预期目标.

In order to simulate the corn stalk powder in the finite element analysis software , this article established the constitutive model of corn stalk powder which based on the D -P yield criteria , and the corn stalk powder ’ s cohesive force and it ’ s friction angle were got by triaxial compression tests .The simplified analysis model of corn stalk powder and single die hole mould was created in three-dimensional (3D) modeling software , and the thermal stress coupling analy-sis of this mould was done in the finite element analysis software to simulate the whole extrusion process of the corn stalk powder .According to the deformation and the force reaction and the fictional stress of this model , the deformation fea-tures and the mechanical characteristics of the corn stalk powder and the time -strain curve were determined and tested which provide foundations to the design of the mould .

Mechanical behavior in the densification of biomass material is closely related to pellet quality. In order to explore the forming mechanism of typical biomass material from loose state to consolidation, the discrete element method (DEM) was introduced to investigate the movement and interaction of the milled corn stalk particles in the compacting process, and the verification experiments were carried out to test the effectiveness of the DEM simulation in this study. Firstly, the three-dimensional (3D) particle contact model of corn stalk powder based on the soft-sphere model of DEM was established, and the constraining walls in DEM model were completely consistent with the compressing cavity boundary conditions in geometric shape and dimension of experimental tests conducted in December, 2014; the loading speed in simulation was also set as the same value as the DEM model. Secondly, the diameter range of simulated particles was configured to 0.4-1.0 mm in accordance to the particle size distribution acquired through the screening experiment and calculation, and the generated particles were fully filled into the whole cavity at the original state before the compressing force was loaded. The mechanical parameters of the particles, such as normal stiffness, shear stiffness and friction coefficient between the 2 contact particles, were set to the values generated at random in specific range which was determined according to compacting experimental data. Thirdly, the comparison of compression stress relaxation data between tests and simulation was carried out and the validity of the simulation was verified by the hypothesis test. It was found that the force data with time from the hypothesis tests and DEM simulation followed the similar tendency, and the absolute error was not higher than 100 N in both initial loading stage and 20 seconds after stress relaxation. In the first 20 seconds of stress relaxation course, the values of absolute error were obviously higher than other time quantum. The consistency of the experimental and simulated data was fairly good on the whole, because there was little statistical significance between 2 group of data at 5% level in the significant difference analysis. The optimal numerical ranges of the mechanical parameters of the simulated particles in DEM model were also obtained. Namely, the normal stiffness was 1.2×104-1.8×104N/m, the shear stiffness was 0.8×104-1.3×104N/m and the friction coefficient was 0.10-0.12. Then, the compressive force was analyzed in DEM model at different compressive displacements, diameters and cone angles using the optimal mechanical parameters of particles. The result showed that the residual forces in stress relaxation were about 600 and 1 300 N respectively when the compressive displacements were set to 26 and 50 mm, which indicated that the compressive displacement had a great influence on pellet morphological stability while other parameters kept constant. When the diameter of single-hole die varied from 8 to 12 mm in DEM model, all the compression forces peaked near 1 100 N as compressing time went on, but the residual stress with 8 mm diameter was much higher than that with 12 mm, and in consideration of the consolidation degree, the recommended diameter was 8 mm compared with the mechanical behaviors of the diameter of 10 and 12 mm. The cone angle had a remarkable effect on the compression force, and the cone angle of 45° was suggested to get a reasonable balance between compression force and pellet density. The study indicates that the discrete element method provides an efficient and effective tool to address some engineering problems in biomass densification, and the soft-sphere model is appropriate to describe the mechanical behavior in the compression process of corn stalk powder.

Cyclone relies on tangential flow rotation movements, separation of dust and air. Device pa-rameters have a great impact on airflow motion parameter and separation effect, how design optimum structure parameters of separator under actual working conditions, is issue that must be considered in the design process. Using the Flow-Simulation module of SolidWorks, to simulate the flow field of Cy-clone separators.In order to determine the optimal parameters combination, using orthogonal design method to arrange the simulation test and combining practical engineering applications. Analysising the flow field whitch is the model of optimal structure parameters and this injection of dust simulates movement in separator. The analysis results show that cone height of 600 mm, exhaust pipe length is 460 mm, the separator with a height of 100 mm, whitch the separation of dust from compressed materi-als can work best.

简述了煤矿用凿岩台车滑轨的特点,介绍了利用三维建模软件Pro/E建立滑轨模型并导入到ANSYS Workbench中,对其进行静力学分析和模态分析.通过分析应力和变形状态,验证了滑轨的结构强度满足要求.通过模态分析得出,滑轨的固有频率与激振频率相差较大,不会发生共振破坏.

In the article, it built up 3D model of maize harvester cutting table frame by using Solid works software, used irregular vibration caused by uneven pavement as drive, did static analysis for cutting table frame of maize harvester by using Solid works Simulation to get stress and strain intensity of key parts and other related information; meanwhile, on the basis of static analysis, to do fatigue analysis for the frame of cutting table according to fatigue curve of Q235 steel material, and got corrupted graphics and other related data. The result theoretically has a certain reference value for the design, inspection, improvement and security evaluation of similar products.

Based on summarizing characteristics of three common kinds of filter method (median filter, mean filter and Gaussian filter) through theory analysis and experiments in Imageware software, a more effective method of smoothing point cloud data was proposed, and the algorithm was realized by programming in MATLAB. Experimental results show that the proposed method combines the advantages of the median filter and mean filter in together, achieves the purpose of smoothing, also ensures the shape of the original data. This research result will lay a foundation for subsequent reconstruction precision of curved surface.

The 3-D entity model of 3-DOF amusement equipment by SolidWorks was bult, dynamics analysis was imposed on the overall of the amusement rides by using SolidWorks-Simulation of finite element analysis software , so as to obtain its vibra-tion characteristics , at the same time distribution maps of stress, displacement and bending of hull beam and pollars were ob-tained by statics analysis, all of them provid the basis for thereaearch on structure improvement and dynamic characteristics a-nalysis.

BIOY-C22 ring die pelletizer is used to grind material into particles through extrusion pressure between the ring die and the roller rolling. The clearance between roller and ring die has a great influence on molding. Generally, clearance gap was in 0.1～0.3 mm. Roller die clearance adjustment structure could adjust the space between the ring die and the roller flexibility, then make up for clearance changes brought about by wear or error. And it makes sure that clearance was in the better scope. Based on the laboratory existing pelletizer ring mode, and from the angle of the parametric design, this paper designed an appropriate form of clearance adjustment structure.

The mathematic model of measuring system of symmetric binocular vision is established.The influences of system structural parameters that include the distance between two cameras(baseline distance 2b) and the angle between optical axes(angle of optical axis 2α) on measuring accuracy are analyzed totally and detailed,and influence trend is obtained.On this basis,a device of binocular stereo vision is established,and the experiments are performed.The experiment results show that the measuring error increases dramatically when 2α is less than 20°,measuring error tends to be flat when 2α is greater than 45°,which is also consistent with theoretical conclusion.By taking measuring error,the measuring range and compact structure into consideration,the angle between optical axes should be 20° to 45°,and the baseline distance should be 300 to 500 mm when binocular vision system is established.

Conveying is the most important steps before forming fuel processing.The transmission mode and the ability have determined the results of compression molding to a certain extent.This paper based on the compression molding device.We designed a practical mechanism,which could meet the requirements of material conveying.After serious discussion,screw mechanism conveying is relatively appropriate way.Through devising the basic parameters of screw rod axis,make it gradually formed a certain transport capacity material conveyor.In addition,through devising the power section and controlling revolving speed,we can get a certain amount of material supply.Through the installation of lead limit switch can control feed time intervals,thus,we achieve our experiment requirements.

To measure and detect the shear stress directly in the field, we developed the device. Designed its structure, working principle, technical parameters and selected its material based on the mechanical characteristics of corn stubble in the field we wanted to get. Applied Solid Works software to construct model for it. In this way, people can know about it intuitively. It is able to detect shear stress of corn stubble in the field directly and accurately. Because shear stress is one of the most important theoretical basis for the design of corn stubbles broken to field machine, maize stubbles harvester machine and corn tillage planter, so design of shear stress detection device for corn stubble in this article is very meaningful and promising.

To get the distribution of stress,displacement and bending moment for seeder rack under the action of static load and dynamic load,and to provide a basis for the optimization improvement of seeder rack,the 3-D model of single frame for com no-tillage planter was set up with software SolidWorks for the tool,static strength analysis and dynamic analysis were imposed on the frame by using SolidWorks-Simulation.The results showed that the stress of the frame under static load was less than the yield strength of material,at the same time,the vibration of the frame under dynamic load was mainly in X and Z coordinate directions.