棉田变量施肥整地联合作业机设计与试验

Design and Experiment of Variable Rate Fertilization Combined Soil Preparation Machine

摘要:

针对新疆缺少棉田施肥整地联合机械和施肥量控制精度不高等问题，设计了一种变量施肥整地联合作业机，可一次性完成耙地、变量施肥、平土、碎土和镇压等作业。对排肥装置、双圆盘开沟机构、缺口耙片组、碎土与镇压组件等关键部件进行设计，通过静力学分析得到影响其工作性能的关键因素，并确定关键部件结构参数；基于北斗自动导航驾驶系统获取行驶速度，并以STM32F405为核心处理器实现了变量施肥控制。以各行排肥量一致性、不同行驶速度下施肥量控制精度以及施肥深度合格率作为施肥性能评价指标，以耙深稳定性、地表平整度标准差、碎土率作为整地性能评价指标，开展了田间试验。试验结果表明，当排肥轴转速为10~60r/min时，各行排肥量一致性变异系数不大于4.27%；当车速为4、7、10km/h时，排肥量控制精度不小于96.70%、95.35%和94.14%；施肥深度合格率为87.04%；耙深稳定性变异系数不大于5.34%；地表平整度标准差不大于4.69mm；碎土率为96.16%。各项指标均达到施肥机械和整地机械标准要求。

Abstract:

In view of the lack of cotton field fertilization combined soil preparation machinery and the low control precision of fertilizer application in Xinjiang, a variable fertilization combined soil preparation machine was designed, which could complete the operations of harrowing, variable fertilization, soil leveling, soil crushing and suppression at one time. The key components such as fertilizer discharge device, double disc trenching mechanism, notch rake group, soil crushing and pressing components were designed. The key factors affecting its working performance were obtained through static analysis, and the structural parameters of key components were determined. Based on the Beidou automatic navigation driving system, the driving speed was obtained, and the variable fertilization control was realized with STM32F405 as the core processor. The field experiment was carried out with the consistency of fertilizer amount in each row, the control accuracy of fertilizer amount at different driving speeds and the qualified rate of fertilization depth as the evaluation indexes of fertilization performance, and the stability of rake depth, standard deviation of surface flatness and rate of broken soil as the evaluation indexes of soil preparation performance. The test results showed that when the rotation speed of the fertilizer shaft was 10~60r/min, the maximum coefficient of variation of the consistency of each row of fertilizer was 4.27%. When the driving speed was 4km/h, 7km/h and 10km/h, the minimum control precision of fertilizer discharge was 96.70%, 95.35% and 94.14%, respectively. The qualified rate of fertilization depth was 87.04%. The maximum coefficient of variation of rake depth stability was 5.34%. The maximum standard deviation of surface roughness was 4.69mm. The broken soil rate was 96.16%. All indexes met the requirements of fertilization machinery and soil preparation machinery standards.