| Rice is the main grain crop in China.That developed rapidly as the high yield and stable production crops in recent years.It is not the effective way only to rely on increasing the planting area.At the same time,the excessive application of pesticides,fertilizers leading to rice and land high residue,it is difficult to meet people’s demand for high-quality rice.In view of the above situation in China,the agricultural experts have put forward two kinds of agronomic mesures that the rice wide-and-narrow row planting and potted seedling transplanting agronomic.These two kinds of agronomic measures respectively could solve the problems of high pesticide and fertilizer residue,and increasing the field and expanding the planting area of the fine grain that named "Daohuaxiang".In this paper,based on the advantages of the two kinds of agronomy,the author put forward the cultivation mode that two kinds of agronomic combined that named rice wide-and-narrow row potted seedling transplanting.However,there was no related equipments supportted,it is difficult to promote the advanced agronomic measures.The existing transplanting equipments at home and abroad were only the wide-and-narrow row planting or rice potted seedling transplanting agronomic measures respectively.The series of wide-and-narrow row planting equipments were still in the state of tradional rice transplanting that the root damage problems still existed.For the rice potted seedling transplanting equipments which were working at equidistance,including the Japanese ejection-type rice potted seedling transplanting machine that are complex and the cost is so high that the farmers can’t be accepted.In the domestic market,such as the double crank rice potted seedling transplanting machine that has some defects: larger vibration,low efficiency and so on,that couldn’t meet the efficient requirements.All kinds of solutions of the other reasearch institutions failed to realize industrialization.Therefore,it is urgent need of research and development of the rice wide-and-narrow row potted seedling transplanting technology and equipment.In order to solve the above problems and the large market demands for the walking type transplanting machine in our country.This paper presented a walking type rice wide-and-narrow row potted seedling transplanting mechamism that had the advantages of small size,simple structure,low cost.In addition,it is convenient and suitable used for the complex and small fileds.Not only it can guarantee the wide-and-narrow row planting requirements,but also can achieve the work of potted seedling transplanting,that realized the combination of the two kinds of agronomic and also filled the market vacancy at home and abroad.According to the above objectives,the main working contents and conclusions of this study are as follows:(1)Research and working principle of the inclined rotary walking-type rice wide-and-narrow row potted seedling transplanting mechanism.Firstly,the paper would combine the physical property of rice seedlings and the formation mechanism of the “8” shape kinematic trajectory and attitude of the inclined rotary rice potted seedling transplanting mechamism to research and analysis.The basic transplanting design requirements of realizing the combination of two agronomics and the horizontal deviation limiting requirements were put forward.According to the above basic objectives,the different forms of the core components for picking and planting,such as rigid body hinge and leaf spring,were analyzed and selected.An inclined rice wide-and-narrow row potted seedling transplanting mechanism was proposed to introduce the working principle of the transplanting mechanism to solve the international problem.(2)Kinematics analysis and modeling of the inclined rotary walking-type rice wide-and-narrow row potted seedling transplanting mechanism.This paper poposed a kind of curve fitting method used for the non-circular gear planetary train and the section of shaping non-circular curve method was set up.According to the characteristics of the free velocity ratio of the conjugate non-circular gears,the theoretical modeling and kinematics analysis were completed.Meanwhile,the inclined transmission theory of the transplanting mechanism was to analysis.That would provide the parameters for the combination of two kinds of agronomic and the theoretical basis for the development of the computer analysis software.(3)Establishment of kinematic objective function of the inclined rotary walking-type rice wide-and-narrow row potted seedling transplanting mechanism.According to the characteristics of the parameter optimization,and the 11 kinematics objectives on account of the transplanting mechanism’s practical experience summary were put forward.The kinematics objectives were converted into the objective function.That would lay the theoretical foundation for the development of the computer analysis software.The objective function include: the seedling picking and pushing angle;the angle between tangent direction of the clamping point and the seedling angle;the distance from the clamping point to the potted seedling surface and the straight distance of the clipping seedling;the distance between seedling and seedling box;the distances between the planting point and the ground and between the gear box and ground and the track height;gear modulus and no interference in the inclined seedling picking.(4)Research on the development of computer simulation optimal design software and optimization rules exploration.Based on the theoretical model,kinematics analysis and objective function,the computer analysis software was developed on the VB 6.0 platform.The influence rule was explored by the X and Y direction parameter in the section curve equation and the different mechanism parameters.The trajectory parameters that meets the scope and the variation rules were affirmed,which provided the optimization rule for the parameter optimization.(5)Parameters optimization and application analysis of the "parameters guidance" optimization algorithm.In the computer analysis software,according to the empirical analysis and the influence of various parameters on the objectives,a set of section curve equation parameters were optimized: a1 =8.80,c1 =4.68,d1 =7.00,f1 =8.36,g1 =-3.50,a2 =14.3,c2 =0.94,d2 =-2.20,e2 =-2,f2 =6.00,g2 =0.40;α1 =87o,α2 =66o,α3 =81o,l 1=70mm,l2 =186.375 mm,k =1.4;this group of parameters were verified by software calculation could satisfy the requirements of the objective function,and meet the requirements of the rice potted seedling transplanting trajectory and attitude.In order to realize the automatic optimization function,the author introduced the application of "parameters guidance" optimization algorithm.(6)Structural design and virtual simulation.Based on the parameters group through the computer optimization,the structural design of rice wide-and-narrow row potted seedling transplanting mechanism was completed,including the improvement and design of inclined transmission mechanism and non-circular gear planetary train.In order to realize the large-scale design requirements of modern design method and avoid the repetition and trival design work,this paper proposed the development and application of variant design software for transplanting mechanism.The core working parts were parametric modeling that could lay a theoretical foundation for the next work,and the assembly interference was tested.The model was exported to complete the virtual prototype simulation test and analyses,the analysis of the rigid-flexible coupling of the leaf spring were completed.According to the above virtual simulation,the consistency and rationality with the theory ware verified.(7)Physical prototype machining of the core working parts and establishing of the test bench.The 3D printing technology and processing of physical prototype were combined to complete the machining and assembly of the transplanting mechanism.Based on the walking machine ZB-430,the test bench was design and improved,including the chassis power connection,walking wheel position and floating plate.The test bench and inclined rotary transplanting mechanism were developed succussfully which prepared for the subsequent test.(8)High speed photography and performance experimental study on transplanting mechanmism.The closed factory seedling raised the experiment seedlings.Based on the high-speed photography,the performance experimental study on kinematic trajectory and attitude of the core transplanting mechanism was completed.The result was consistent with the theoretical design and virtual simulation results,so that can ensure the correct reasonable operation.In the end,the experiment was carried out on the seedling picking and planting of the rotary rice wide-and-narrow row potted seedling transplanting mechanism.Through performance test,it proved that the mechanism could satisfy the requirements of the two kinds of transplanting agronomic at the same time,and determine the best running speed and efficiency should be less than 150 rpm. |
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