Optimization Design And Experimental Study On Integrated Transplanting Mechanism Of Take And Plant For Vegetable Blanket Seedlings

Vegetable production plays an important role in agriculture in China.At present,the mechanization and automation level of vegetable production is low,which is the weak link of agricultural modernization in China.The automatic transplanting method of plug is restricted by seedling picking technology and support system.In comparison,the blanket seedling transplanting supporting system is mature and efficient,and is widely used in rice.In order to achieve high-efficiency and low-loss transplanting of vegetable carpet seedlings,it is necessary to cultivate seedlings with ‘carpeted root,high density and short and strong ’.In this paper,the orthogonal experiment with strong seedling index and morphological characteristics as multi-index was carried out for the seedling raising method of broccoli blanket seedlings.The variance and range analysis of multi-index test data were carried out to obtain the optimal combination of seedling raising parameters suitable for mechanized transplanting,which provides a theoretical basis for the study of seedling picking mechanism of broccoli blanket seedlings and the design of transplanting mechanism.In terms of mechanism,a set of picking and digging mechanism combined with seedling picking mechanism and hole digging mechanism was proposed to achieve seedling picking and hole digging,and the simple mechanism was used to efficiently realize the transplanting of broccoli blanket seedlings.The main contents of this paper are as follows:1)The three-factor and three-level multi-index orthogonal experiment of broccoli carpet seedling was carried out.The robust seedling index and morphological characteristics were taken as the multi-index research objects,and the comprehensive scoring method was established.The range analysis and variance analysis of the comprehensive scoring value were carried out to obtain the optimal seedling parameter combination and the significant influence relationship.The best combination of parameters was used to cultivate transplanting objects,which provides a basis for the design of key components of transplanting mechanism,so as to realize the combination of agronomy and agricultural machinery.2)The composition of the existing transplanting mechanism was studied and analyzed,and the seedling picking mechanism was designed.The planar four-bar mechanism was generated by three-position motion,and the point solution curve model of the three-precision pose hinge and the solution domain of the rod group were established.The trajectory control points were introduced to optimize the fitting trajectory.The total transmission ratio of the gear train and the total transmission ratio of the secondary distribution were obtained.The gear pitch curve was solved by the transmission ratio.Based on this theory,the theoretical model of the seedling picking mechanism of broccoli blanket was designed,and the parameter solution domain of the seedling picking mechanism and the total transmission ratio of the gear train were obtained to solve the gear train section curve of the seedling picking mechanism.3)The establishment and solution of the mathematical model of the deformed elliptical planetary gear train was expounded,and the determined planetary carrier length and the initial angle of the planetary carrier of the seedling picking mechanism were used as the basis for the design of the deformed elliptical planetary gear train,and the burrowing mechanism planetary gear was designed.Complete the gear train combination of the seedling picking mechanism and the digging mechanism,determine the optimization target,analyze the influence of the parameters of the digging mechanism on the trajectory,so as to determine the trajectory of the seedling picking and digging,and provide the parameter basis for the overall design of the transplanting mechanism.4)After the mechanism parameters are obtained,the model was designed and assembled in the three-dimensional software,and the simulation test was carried out in the virtual simulation software.After the trajectory was obtained by simulation,the parts were processed and tested for the physical prototype.By comparing the physical prototype trajectory with the simulation trajectory,the prototype performance test was carried out.The average seedling picking success rate was 91%,the hole digging success rate was 98 %,and the planting success rate was 85%,which met the agronomic requirements of blanket seedling transplanting.