| Eggplant is one of the most widely cultivated vegetable crops in the world and China is the country with the largest cultivation area and the highest total output of eggplant.As one of the main vegetables in summer and autumn,eggplant is rich in nutrition,simple in cultivation and management,and long in growth period.To plant eggplants,people tend to adopt the method of seedling transplanting.At present,the method of manual transplanting is mainly adopted in China.However,this method is labour-intensive and inefficient.The domestic transplanting equipment is mainly semi-automatic transplanter and it is inefficient due to the restriction of manual transplanting.In European countries,mechanical and electrical integration achieved by information technology is used to perform three actions of picking up,transporting and planting the potted seedlings with three or four mechanisms.This kind of machine is difficult to popularize owing to its complicated structure,high cost and inconsistence with China’s national conditions.Now,the efficient and simplified full-automatic eggplant potted seedling transplanting mechanism,which has not been used in China,is the development direction of the eggplant seedling transplanting.A full-automatic eggplant potted seedling transplanting mechanism is put forward based on Newton interpolation gear(a kind of non-circular gear proposed according to Newton interpolation method).Agronomy and agricultural machinery are combined to explore the cultivation conditions of eggplant seedlings.By establishing the mathematical model of transplanting mechanism and optimizing the parameters,this paper obtains the trajectory and attitude of eggplant seedling transplanting,and carries out the trajectory verification test,seedling pickup experiment and planting experiment.The main contents of this paper are listed as follows:(1)By analyzing the current situation of the research on vegetable potted seedling transplanter at home and abroad,this paper finds out the problem faced by the vegetable transplanter,i.e.how to complete the full automatic transplanting of eggplant seedlings efficiently and simply.(2)The full-automatic eggplant seedling transplanting involves many aspects such as soil,seedling,machinery and so on.What’s more,it is necessary to adapt to each other.In order to reasonably design and optimize the full-automatic eggplant potted seedling transplanting mechanism,this paper carries out seedling pickup experiment and seedling falling experiment,and studies the physical properties of northern eggplant potted seedlings.In addition,mathematical statistics method is used to find suitable cultivation conditions and it provides a correct idea for the optimal design of transplanting mechanism.(3)In order to realize the full-automatic transplanting of eggplant potted seedlings,it is required that transplanting mechanism should not only complete three actions of picking up,transporting and planting the potted seedlings,but also meet the special plant spacing growth characteristics of eggplant potted seedlings.Therefore,the complicated attitude and motion trajectory of the full-automatic eggplant potted seedling transplanting mechanism are obtained.In a non-uniform transmission,pitch curve has a small variation range since it only depends on elliptic gear,oval gear and eccentric gear.As a result,it is difficult to satisfy the requirements of the complex trajectory,attitude and plant spacing.In order to solve this problem,the Newton interpolation method is used to form the pitch curves of the non-circular gear and the control points by interpolation is used to realize the change of the non-circular gear pitch curves,which contributes to the achievements of complex trajectory,attitude and special plant spacing requirements.(4)According to the agronomic requirements,the manual transplanting action and the movement status of the full-automatic eggplant potted seedling transplanting mechanism,the optimization target of the transplanting mechanism is determined.Optimization design and analysis software(Registration No: 2018SR101037)for eggplant potted seedling transplanting mechanism based on Newton interpolation gear was developed with the help of Visual Basic 6.0.A group of parameters that meet agronomic requirements are obtained by means of human-computer interaction,the optimization design software and the parameter-guided heuristic optimization algorithm.(5)According to parameters optimized by the software listed above,this paper completes the 2D and 3D structure design of the transplanting mechanism,virtual assembly and interference check.(6)The virtual simulation test of the eggplant potted seedling transplanting mechanism is completed with the help of ADAMS2013 software.In addition,3D printing technology is used to make the physical prototype for trajectory verification test,which verifies the validity and feasibility of the mechanism.Besides,the seedling pickup experiment and planting experiment prove the practicability of the mechanism. |
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