气送式玉米高速精量排种器供种系统设计与试验

针对气送式玉米高速精量排种器进行高速精量播种时排种器内存种量波动较大，无法维持最佳作业状态的问题，提出通过改进供种装置结构、优化供种控制模型的技术思路。设计了一种智能供种系统，采用可替换轮片的新型供种轮结构和以正弦函数为基础的波动变量供种方式，根据供种效果实时调节供种速度波动幅度，从而使排种器内的存种量保持在较好区间，确保排种器在较高作业性能下进行持续性工作。对关键零部件进行了结构参数设计，通过离散元仿真和台架试验获取并验证了不同结构的供种轮较优工作区间，同时对波动变量供种模型性能进行了试验验证。试验结果表明，新型供种轮能够通过改变自身结构在供种速度250~1500g/min范围内将供种速度变异系数保持在20%以下。优化后新型波动变量供种控制模型将使供种速度以波动变量供种的方式进行平滑变化，在供种速度500~1500g/min范围内围绕供种需求进行100g/min左右幅度的波动供种，满足玉米精量播种的技术要求。

Design and Experiment of Intelligent Seed Supply System of Air-assisted High Speed Precision Maize Seed Metering Device

Aiming at the problem that the seed quantity of the high speed precision seed discharging device can not maintain the best working state due to the fluctuation of the seed quantity in the device, a technical idea was put forward to improve the structure of seed feeding device and optimize seed feeding control model. An intelligent seed supply system was designed, which adopted a seed supply wheel structure with replaceable wheels and a wave variable supply mode based on sine function. The fluctuation amplitude of seed supply speed was adjusted in real time according to the seed supply effect, so as to keep the seed quantity in the seed discharge device in a good range and ensure the continuous work of the seed discharge device under high operating performance. The structural parameters of the key components were designed, and the advantageous operating intervals of thetype seed feeding wheel with different structures were obtained and verified by discrete element simulation and bench test. The experimental results showed that the type of seed feeding wheel could maintain the variation coefficient of seed feeding speed below 20% in the range of 250~1500g/min by changing its own structure. After optimization, the type of fluctuation variable seed supply control model would make the seed supply rate change smoothly in the way of fluctuation variable seed supply, and carry out the fluctuation seed supply in the range of 500g/min to 1500g/min around the supply demand. The research result can meet the technical requirements of corn precision sowing.