| At present,more than half of the world's vegetables are produced and consumed in China.Vegetables have become the most widely grown crops in China except for food crops.Vegetables not only provide essential vitamins and other mineral elements for human life,but also serve as an important channel for farmers to increase their income.Large-scale seedling cultivation and transplanting can effectively improve the survival rate of seedlings,reduce production costs and improve economic benefits.Therefore,it is of great significance to study the key technical problems of automatic vegetable pot seedling transplanting machinery for promoting the development of vegetable industry and improving the level of agricultural mechanization in ChinaAiming at the shortcomings of low efficiency,high cost and complex structure of automatic vegetable bowl seedling transplanting machine at home and abroad,and the problems of low success rate at high speed,poor seedling pushing effect,interference between pot seedling body and seedling pick-up claw of seedling pick-up mechanism of planetary gear train with combined non-circular gear transmission.A rotating seedling retrieving mechanism based on combined incompletely variable eccentric circular-non-circular gear drive is proposed.Then the kinematics analysis,parameter optimization,three-dimensional parametric design,virtual simulation and seedling harvesting test of the seedling picking mechanism were studied.In this paper,the main research contents and results are as follows:1)To effectively solve the problem of the seedling picking mechanism by our research group,a new seedling picking mechanism of Planetary Gear Train with Combined Non-circular Gear Transmission was proposed on the basis of denaturing the incomplete eccentric circle in the mechanism.The kinematics of the new mechanism is analyzed and its kinematics model is established2)According to the kinematics model of seedling picking mechanism,the software of assistant analysis and optimization of seedling picking mechanism is compiled with VB6.0software.The effect of coefficient of degeneration m11 on seedling trajectory was analyzed through the software.In the way of human-computer interaction,the design objectives are achieved by adjusting the design variables,and a set of optimum parameters satisfying the requirements of seedling collection are finally obtained.3)Secondary development of NX10.0 based on C++,a three-dimensional parametric design system for seedling-picking mechanism of combined non-circular gear planetary gear train has been established.With this system,the three-dimensional model of the new seedling picking mechanism corresponding to the design parameters can be generated in real time after the design parameters are modified.The three-dimensional model of mechanism is imported into ADAMS software for virtual simulation test.The virtual simulation trajectory and theoretical analysis trajectory of seedling harvesting mechanism are compared to verify the reliability and correctness of mechanism design.4)Using the established three-dimensional parametric design system,the two-dimensional drawings of seedling picking mechanism parts are derived,and the physical prototype processing is carried out.After assembly is completed,kinematics and seedling harvesting tests that broccoli seedlings as experimental seedlings were conducted.The real trajectory obtained from the experiment is compared with the theoretical trajectory and the attitude of the seedling claw is analyzed.Experiments were carried out under different rotational speeds of seedling-taking mechanism to obtain the corresponding success rate of seedling-taking and seedling-pushing,and analyzed its seedling-taking effect.When the speed of the new mechanism is 50r/min,the success rate of seedling collection reaches 96.3%,which is higher than the original mechanism,and the success rate of seedling pushing is also improved,and the working performance is better. |
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