摘要
为研究指夹式玉米精量排种器籽粒投送运移规律,提高排种器导种性能,建立了导种投送过程的运动学和动力学模型,分析了各因素对运移稳定性及投送落种轨迹的影响。采用多因素二次通用旋转组合试验研究了工作转速和倾斜角对排种均匀稳定性的影响,运用Design-Expert 6.0.10软件对试验数据进行优化分析得到其最佳工作条件。在此基础上,运用镜面反射成像原理,搭建了排种轨迹测定试验台,结合高速摄像与图像目标追踪技术对落种籽粒轨迹运移规律进行了研究。试验结果表明,在工作转速为15~45 r/min、倾斜角为0°工况下,籽粒正面轨迹及侧面轨迹的水平位移随工作转速增加而增加,株距变异系数随工作转速增加而降低;当工作转速大于35 r/min时,籽粒轨迹及落点位置分布逐渐离散,株距变异系数明显增加,其正面水平位移稳定在12.9~14.3 mm内,侧面水平位移稳定在3.7~4.8 mm内,平均株距变异系数为15.13%。在工作转速为30 r/min、倾斜角为-12°~12°工况下,轨迹投种角随倾斜角的增加而减小,其整体角度稳定在66.4°~79.6°内。该研究为优化设计指夹式玉米精量排种器关键部件及配套导种管提供了参考。
In order to improve the guiding migration performance of pickup finger precision seed metering device,the steady migratory mechanism of guiding-seed system was studied. The kinematics and dynamics models of guiding-seed and dropping-seed processes were established based on its working principle. The influences of various factors on dropping trajectory and migration stability were analyzed.The quadratic general rotary unitized design was carried out by taking the rotational speed of seed meter and tilt angle as experiment factors, and the seeding qualified index and variation coefficient as experiment indexes. Based on experimental data,a mathematical model was built by using the DesignExpert 6. 0. 10 software,and the experiment factors were optimized,the best combination was achieved.On this basis,a kind of dropping trajectory measuring test platform was designed and built based on the theory of mirror reflection. And then the three-dimensional space velocities of the falling corn were measured and analyzed by high-speed photography and target tracking technology. The single factor tests for factors,including rotational speed and tilt angle,were carried out and the corresponding regression equations were obtained by analysis. Experimental results showed that when the rotational speed was between 15 r / min and 45 r / min and the tilt angle was 0°,the horizontal displacements of trajectories of frontal and profile dropping seed were increased with the increase of rotational speed and the variation coefficient of seeding was decreased with the increase of rotational speed. As the rotational speed was greater than 35 r / min,the trajectories and landing positions of corn grains were gradually discrete and the variation coefficient of seeding was significantly increased,and its horizontal displacements of frontal trajectory were stabilized within the range of 12. 9 ~ 14. 3 mm,the horizontal displacements of profiletrajectory were stabilized within the range of 3. 7 ~ 4. 8 mm,and the average variation coefficient was
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2017年第1期29-37,46,共10页
Transactions of the Chinese Society for Agricultural Machinery
基金
"十二五"国家科技支撑计划项目(2014BAD06B04)
关键词
玉米
指夹式精量排种器
导种投送
机理
试验
corn
pickup finger precision seed metering device
guiding and dropping seed
mechanism
experiment
