多杆式零速度钵苗移栽机植苗机构运动学模型与参数分析

Kinematics modeling and characteristic analysis of multi-linkage transplanting mechanism of pot seeding transplanter with zero speed

为了分析多杆式零速度钵苗移栽机植苗机构的作业性能,建立了该机构的位移、速度和加速度方程,用Visual Basic 6.0语言编写了该机构的辅助分析和仿真程序。利用该程序分析了几个主要参数对该机构运动特性的影响:曲柄摇杆机构中的曲柄长度对栽植嘴的轨迹和形成的穴口大小影响都很大,而且对移栽后动轨迹的垂直度影响也很大;连杆长度影响栽植嘴的轨迹高度,对形成的穴口的大小和移栽后动轨迹的垂直度影响不大;摇杆长度和连杆的夹角对栽植嘴的轨迹形状和形成的穴口大小影响都不大,但都对移栽后动轨迹的垂直度有影响。根据参数影响分析结果,利用该程序找到一组较优机构参数,其对应的轨迹和姿态能满足蔬菜移栽农艺的要求,且植苗时水平速度为0.03 m/s,实现零速度移栽。

To analyze the working performance of the zero-speed multi-linkage transplanting mechanism of pot seeding transplanter which was proposed by this paper, the equations of displacement, velocity and acceleration of the zero-speed multi-linkage pot seeding transplanting mechanism were established. Also a computer-aided analytical and simulative program of this mechanism were compiled based on Visual Basic 6.0. And the influences over the kinematic characteristics of this mechanism by some important parameters were analyzed by this program. The length of the crank of the crank-rocker mechanism had significant influence not only over the trajectory shape of the transplanting tip and the size of the transplanting hole, but also over the verticality of the crop after being transplanted. The length of the linkage had influence over the trajectory height of the transplanting tip, while it had little influence over the size of the transplanting hole and the verticality of the crop after being transplanted. The length of the rocker and the included angle between two linkages had little influence over the trajectory shape of the transplanting tip and the size of the transplanting hole, and had significant influence over the verticality of the crop after being transplanted. A group of preferable mechanical parameters were obtained by this program, whose corresponding trajectory and posture could meet the demands of vegetable transplanting. The horizontal velocity is 0.03 m/s, so the transplanting with zero-velocity can be achieved.