杂交稻智能恒量精密播种机理及关键技术研究

Hybrid rice is a new kind of rice varieties with good quality and high yield, which has popularized and applied in large area of China. It requires sparse and precision seeding, and increases yield by its strong tiller ability. But the existing mechanization planting technology can not meet the planting requirement of hybrid rice, so it is urgent to research and exploit the mechanism of hybrid rice precision seeding technology. The project researches working mechanism of the feeding seeds unit and uniform seeds unit when the hybrid rice seeds are under vibration. Based on the theory of finite element method, discrete element method, motions of seeds in vibration seed chamber and distribution rule of the seeds in the V-T type vibration plate are analyzed, and the uniform queuing model of seeds is established in the V-shaped groove. The uniform distribution and orderly queue condition of the uniform seeds unit are put forward under vibration. The working parameters optimization of feeding seeds unit and uniform seeds unit are carried out. Based on the embedded computer and machine vision technology, dynamic on-line detection of seedling tray seeding performance is achieved. The quality of seed particles in connected region is detected by multi-features extraction technology and feature optimization technology method, meanwhile, the acquired tray image sequence is automatically stitched to form an entire seedling tray image, so that the sowing quantity of the seeded tray can be precisely detected and the further seeding rate signal model is set up. According to the control algorithm, constant seeding rate is retained automatically by control the feeding seeds unit and uniform seeds units. At last, a new intelligent and constant precision seeder on hybrid rice with excellent performance is developed, and provides theoretical value and practical application significance for developing Hybrid rice mechanized planting production.

杂交稻是品质优良、产量高的新型水稻品种，目前已在我国大面积推广应用，但它的栽培要求少本稀植、利用分蘖能力提高产量，现有的机械化播种技术不能满足此要求，亟需进行杂交稻精密播种技术的机理探讨。本项目研究杂交稻种子在振动作用下的供种和匀种机构工作机理，基于有限元法、离散单元法等理论分析种子在振动种室的运动状态，在V-T型振动种盘中的分布规律，建立种子在V型槽内均匀排队模型，提出在振动作用下匀种机构的均匀分布、有序排队条件，进行供种与匀种机构的工作参数优化。基于嵌入式计算机与机器视觉技术，进行在线动态连续检测秧盘的播种性能，采用多特征提取技术和特征优选技术法对采集的图像序列检测种子连通区域的颗粒数，自动拼接整秧盘播种图像，预测秧盘播种性能，建立播种量预测信号模型，根据控制算法，自动控制供种与匀种机构保持播种量恒定。研制出性能优良的新型杂交稻智能恒量精密排种器，为杂交稻机械化栽插的产品开发提供依据。

杂交稻栽培强调少本稀植、利用分蘖能力提高产量，现有机育秧播种技术不能满足此要求，亟需进行杂交稻精密播种技术机理探讨，加快我国杂交稻机械化发展。. 本项目基于离散元法、振动分析、机器视觉和控制技术等，针对杂交稻芽种的复杂物理特性，提出振动种室、多层交叉导种板与螺旋勺式槽轮的供种结构,采用离散元法仿真振动供种过程，明确了振动作用有利于延迟种层断开时间、减小种箱内种群的滞留面积，提高稻种分布的蓬松度，表征了稻种在交叉导流式振动种箱内的流动特性，揭示了定量供种机理。创制V-T型振动种盘匀种结构，采用振动理论和离散元法，解析种子在T型板及V型种槽板上的均匀流动、有序排队性能。基于嵌入式系统的机器视觉技术，优选BP神经网络算法进行秧盘播种性能在线检测，得到毯状盘和钵体盘播种合格指数平均准确率分别为97.84%和97.77%。根据反馈的播种性能调控播种量实现智能恒量播种，研制出杂交稻智能恒量播种装置。试验表明，毯状盘每格2-5粒合格指数为92.12%、空穴指数0.39%，钵体盘每穴1-3粒合格指数为95.22%、空穴指数1.48%。研制的杂交稻智能恒量播种装置，装机于2ZSB-500型智能水稻秧盘育秧精密播种生产线上，通过多点试验，示范面积10余万亩，展示出良好的示范效果，形成一种先进的杂交稻机育插秧新方法，与传统机育插秧技术相比节省种子50%、提高产量约10%。. 项目运行期间发表论文12篇（SCI收录3篇、EI收录6篇）；申报专利9件（发明专利7件）、授权发明专利1件和实用新型专利2件；培养毕业研究生8人（博士生3人）；获广东省农业技术推广一等奖1项。研究成果揭示了振动式精密播种装置实现种子振动分离、充填和有序排队的设计理论，系统形成了在复杂背景下采用机器视觉技术进行在线快速检测育秧盘播种性能、以及智能调控播量的方法，为水稻秧盘育秧播种装置的研制提供了科学的理论依据，研究成果已显示出应用前景。