Optimization Design And Experiment Of Extensible Potted Tomatoes Seedling Transplanting Mechanism

Affected by natural factors such as temperature and climate,tomatoes are generally planted by transplanting.In particular,transplanting can't only increase accumulated temperature and increase yield,but also effectively avoid the effects of disasters such as frost and cold spring,in northeastern and northwestern of China.However,the mechanization and automation of tomatoes transplanting are lower in China,at present,artificial transplanting is still the main one,the common tomatoes transplanting machines on the market are mostly semi-automatic transplanting machines,the seedlings are picked by hand and planted by the planting mechanism.The main problems that limit the development of automatic transplanting machines are : the Coordination between taking and planting is inaccurate in the process of operation,poor quality of transplanting and damage to seedling stems or roots during the process of picking seedlings.For the above design problems,this paper proposed an extensible potted tomatoes seedling transplanting mechanism for the method of picking up the soil pot,the mechanism cooperates with the non-circular gear planetary gear train and the new extensible end-effector,which can realize a set of mechanisms to complete the action of taking,transporting and planting,the mechanism can avoid the damage of soil and roots during the process of taking the soil pot and it provides an important reference value for the research of tomato transplanting.The main research contents and conclusions of this paper are as follows:(1)Based on the analysis of existing transplanting techniques and implements,an end-effector that can pick up the soil pot is designed(Patent No:201810293364.1),and the non-circular gear planetary gear train and the extensible end-effector are matched to realize the the action required for tomatoes seedling transplanting.The mechanism can effectively avoid the problems of the previous transplanting mechanism,the damage of the soil pot and the root system,the structure is simple and the efficiency is high.(2)The trajectory requirements of tomatoes seedlings transplanting was proposed according to the agronomic requirements of tomatoes seedling transplanting and simulating the posture of artificial transplanting,the working principle of the transplanted seedling transplanting mechanism was introduced,and the theoretical model of the mechanism was established.(3)According to the theoretical model of the mechanism and combining with the agronomic requirements of tomatoes transplanting,the optimization goal of the mechanism wasset.Relying on the optimization design platform of the transplanting organization of this research group,the optimization design software for the transplanting tomatoes seedling transplanting mechanism was developed(Registration No:2018SR403608;2018SR322860),the optimization software was used to optimize the transplanting mechanism,and a set of parameters satisfying the requirements of tomatoes transplanting and structural design were obtained.(4)In order to verify the rationality and feasibility of the mechanism under the structural parameters,the absolute rotation angle of the planting arm and the absolute motion trajectory of the transplanting mechanism were analyzed;comparing the theoretical trajectory of the extensible transplanting mechanism with the theory of the non-extensible transplanting mechanism,the advantages of the extensible transplanting mechanism were explained.(5)3-D structural design and assembly were established based on a set of optimal structural parameters obtained from optimization,and the assembly model was imported into Adams2014 for virtual simulation,the curve of the relative motion trajectory and absolute motion trajectory was compared with the theoretical trajectory,and the interference detection was performed to verify the rationality and correctness of the structural design.(6)The 3D printing technology was used to process the core working parts of the physical inspection machine.The printed parts were assembled,and the actual working trajectory of the physical inspection machine was obtained through high-speed photography technology,it was compared with the theoretical trajectory to further verify the correctness of its design.(7)The potted transplanting tomatoes seedling transplanting mechanism was installed on the test bench for performance test.The success rate of seedling picking was 92.8%,and the success rate of transplanting was 89.7 %,the planting pass rate was 86.4%,and the planting excellent rate was 59.4%,which was in line with the transplanting requirements,and verified the practicality of the mechanism.