粳稻定向排种装置种子分离机构仿真分析

Simulation Analysis of Seed Separation Mechanism of Directional Precision Seeding Device for Super Rice

为进一步提高超级稻精密育秧播种精度,设计开发了一种定向排种装置,建立了单粒种子分离机构的数学模型,并用Visual Basic6.0语言编写了该机构的辅助分析和仿真程序。同时,分析了主要参数对该机构运动轨迹的姿态和位移的影响:五杆机构中的曲柄长度l1对分离板运动轨迹的姿态无影响,但对分离板在x轴和y轴方向的位移有较大影响;连杆长度l2和摇杆长度l3不仅对分离板运动轨迹的形状和姿态影响较大,而且对分离板在x轴和y轴方向的位移也有较大影响;支架安装角θ1、输出杆长度l5及其与连杆的夹角θ3对分离板运动轨迹的形状影响较小,但对分离板运动轨迹的姿态和在x轴和y轴方向的位移均有较大影响。根据参数影响分析结果,以分离板运动的设计轨迹为优化目标,通过人机交互方式对该机构进行了运动仿真,得到了一组较优机构参数。利用Adams软件对优选后的机构进行了运动学仿真,其输出点轨迹、速度和加速度满足设计要求。仿真结果可为北方粳稻植生带育秧设备定向排种装置的设计提供理论依据。

The agronomy experimental results indicate that sowing quantity and seedling quality are the main restricting factors for good quality and high yield of super rice .One of the important methods measures for increasing super rice yield is to apply the advanced precision seeding technology to the cultivation of high quality seedlings .Based on the suction precision seeding device for nursing rice seedlings , in which the seeds were positioned and fixed with paper precisely , the present paper designed a new directional seeding device in order to further enhance the seedling accuracy of super hybrid rice in low seeding rate .The mathematical model of five-linkage single seed separation mechanism was established and its trajectory posture and moving distance were simulated using Visual Basic 6 .0 , based on important design parameters . It was found that the length of the crank of the multi-linkage mechanism l1 had not significant influence on the trajectory posture of the separating plate , but it affected very much on its moving distance in x and y direction .The length of the rockerl 2, the linkage l 3 and the bracket l 4 had significant influence on not only the trajectory shape and posture of the separating plate , but also on its the moving distance of in x and y direction .The installation angle of the bracket θ1, the length of the output link l 5 and the angle between the output link and the connecting rod θ3 had little influence on the traj-ectory shape of the separating plate , but they all had significant impact on the trajectory posture and moving distance of the separating plate in x and y direction .Based on simulation on this mechanism utilizing the man -machine interactive method, a group of preferable mechanical parameters were obtained ：l1=7.7mm ,l2=23mm, l3=26mm, l4=37mm,l5=36mm,θ1=64°,θ3=12°,and kinematics simulation for the optimized five-linkage mechanism was performed with ad-ams.The result shows that the movement trajectory ,speed and acceleration could meet the design requirement of five-bar mechanism very well .The research may be used as designing basis for the directional precision seeding device .