种群扰动对离心机械式玉米高速精量排种器性能的影响

Effect of Disturbed Seeds on Performance of Centrifugal Mechanical Maize High-speed Precision Seed Metering Device

摘要:

为克服传统机械式玉米精量排种器在高速作业过程静态堆积种群导致充种效率低问题，本文设计一种扰种机构将种群离散化，增加种子流动性，提高充种精度和排种器性能。对扰种机构进行理论分析与结构设计，采用离散元仿真开展扰种齿形状、扰种齿高度及种群高度对排种性能的影响规律研究，明确各因素影响机理。以扰种齿形状、扰种齿高度、种群高度为试验因素，以破碎率、合格率、重播率、漏播率为试验指标进行三因素三水平中心组合正交试验，并对试验数据进行多元回归和响应曲面分析，得到各因素对指标的影响关系。采用多目标优化方法，确定最佳参数组合为：作业速度为13 km/h、扰种齿形状为D型、扰种齿高度为11.20 mm、种群高度为66.40 mm，此时合格率为94.75%，重播率2.71%，漏播率2.54%，破碎率0.42%，满足高速条件下玉米精量播种技术要求。

Abstract:

Aiming to improve the performance of the mechanical maize precision seed metering device in high-speed operation, a seed-disturbing mechanism was designed to discretize the originally static accumulation of seeds, increase the mobility of seeds, and improve the precision seeding conditions. The theory analysis and structure design of the disturbing mechanism were carried out. The influence of disturbance teeth shape, disturbance teeth height, and seed pile height on the seeding performance was studied by the discrete element simulation analysis method. The influence of each factor was clarified. To verify the theoretical analysis results and obtain the best performance parameters, the shape of seed-disturbing teeth, the height of seed-disturbing teeth, and the height of the seed pile were used as test factors. The breakage rate, qualified rate, multiple rate, and missing rate were used as test indicators to carry out the three-factor and three-level center orthogonal test. The test data were analyzed by multiple regression analysis and response surface analysis using Design-Expert software. The influence relationship of each factor on the index was obtained. A multi-objective optimization method was used to determine the better parameter combination. When the operation speed was 13 km/h, the shape of seed-disturbing teeth was D, the height of seed-disturbing teeth was 11.20 mm, and the seed layer height was 66.40 mm, the qualified rate was 94.75%, the multiple rate was 2.71%, the missing rate was 2.54%, and the breakage rate was 0.42%, which met the technical requirements of precision seeding under the condition of high speed.