稻麦精准变量施肥机排肥性能分析与试验

摘要

为提高基于近地光谱技术的稻麦精准变量施肥机排肥性能稳定性,改善变量施肥控制精度,建立了外槽轮式变量施肥机离散元仿真模型,运用离散单元法和EDEM 2.2软件对施肥机排肥过程进行性能分析和数值模拟,研究不同排肥器结构和施肥控制策略对施肥机排肥稳定性的影响,并通过台架试验和田间试验验证仿真模型的准确性.结果表明:改进后的排肥器施肥量变异性系数明显减小,标准差减小14.59 9,变异系数降低9.9％;采用转速优先控制策略,当槽轮开度为19.34 mm时,排肥量稳定性系数最佳为1.09％;采用开度优先控制策略,当槽轮转速为55.75 r/min时,排肥量变异性系数最小为1.85％;与验证试验结果相比,误差最大为14.06％.结果验证了离散元仿真方法分析颗粒运动过程的准确性,表明所设计改进的排肥器能够提高施肥机排肥稳定性,满足稻麦精准变量施肥要求.%As one of the most widely applied technology at present,near-earth spectrum detection technology has been used in precise variable fertilizer applicator for rice and wheat.In order to improve fertilizing performance stability and control precision of variable rate fertilizer applicator,the discrete element simulation model of outer groove-wheel variable applicator was established.To achieve the optimal structure of outer groove-wheel fertilizer apparatus,the discrete element method (DEM) and EDEM 2.2 software were put into use to analyze and numerically simulate the fertilizing performance.The effect of different fertilizer apparatus structures and control strategies for fertilizing on the stability of variable fertilization was studied,and with bench test and field trial to verify the accuracy of simulation model.The results showed that the fertilization variability of improved apparatus was significantly decreased,and the standard deviation was decreased by 14.59 g,the variation coefficient was reduced by 9.9％.When the control strategy of speed priority was adopted,as the groove-opening was 19.34 mm,it had the optimum fertilizer stability of 1.09％.When the control strategy of groove-opening priority was adopted,as the rotary speed of groove-wheel was 55.75 r/min,the minimal fertilizer variability was 1.85％.And compared with the verification test results,the errors were less than 8.87％,9.52％ and 5.50％,respectively,verifying the accuracy of simulation and analysis for particle movement process in agricultural equipment using the DEM.The study illustrated that the improved fertilizer apparatus could perfect the stability of fertilizer and satisfy the demands of precision variable fertilization.