秸秆深埋还田仿生开沟装置优化与试验

为解决秸秆深埋还田工作中开沟深度不够、深埋率低、开沟阻力大等问题，对自行研制的气力式秸秆深埋还田机的开沟装置进行了优化设计。提出一种仿螳螂前端足曲线的秸秆开沟刀参数优化设计，利用阿基米德等进螺线设计的侧切刃具有滑切能力，可切割土壤完成开沟作业。利用Matlab对螳螂前端足进行二值化、膨胀、边缘坐标处理得到仿生开沟刀，使用离散元软件EDEM对设计出的仿生开沟刀和普通开沟刀进行仿真对比，并对仿真结果进行土槽试验验证。试验分析结果表明，相比于普通开沟刀，仿真开沟刀在开沟过程中可减少9.48%的阻力。利用Design-Expert 8.0软件的二次正交旋转组合试验设计结合响应面法，分别建立秸秆深埋率和工作效率与机具前进速度、秸秆深埋深度和秸秆覆盖量的回归数学模型。通过分析表明，各因素对秸秆深埋率的影响由大到小依次为：秸秆覆盖量、秸秆深埋深度、机具前进速度；各因素对工作效率的影响由大到小依次为：机具前进速度、秸秆深埋深度、秸秆覆盖量；交互作用中，秸秆深埋深度和秸秆覆盖量、机具前进速度与秸秆覆盖量对工作效率影响显著。经过优化求解，在深埋率权重为0.7、工作效率权重为0.3的情况下得到开沟装置最佳工作参数，在机具前进速度为1.63m/s、秸秆深埋深度为27.97cm、秸秆覆盖量为340.54kg/hm2时，秸秆深埋率为90.491%，工作效率为5.4hm2/h。

Optimization and Experiment on Bionic Deep-buried Device for Returning Straw in Field

In order to solve the problem of insufficient depth of trenching, low depth of deep-buried, high resistance to trenching in straw returning work, the design of trenching device for pneumatic straw returning to field was optimized. A parameter optimization design of the deep-buried straw was proposed to simulate the front-foot curve of the rake, and the cutting ability of the side cutting edge designed by Archimedes'' helical design was used to cut the soil to complete the trenching operation. Matlab was used to reduce the resistance and consumption during the trenching operation of the bionic part obtained by binarization, expansion and edge coordinate processing of the front foot, and then the discrete element software EDEM was used to design the bionic trencher and the ordinary trencher. The simulations were compared and the simulation results were verified by the soil trough test. The analysis of the test results showed that the simulation trencher can reduce the resistance by 9.48% compared with the ordinary trencher during the trenching process. The quadratic orthogonal rotation combination design of Design-Expert 8.0 software was used in combination with response surface methodology to establish a regression mathematical model for deep burying rate and operating efficiency of the straw, speed of implement advancement, deep burial depth of straw and straw mulching amount. The analysis result showed that the order of the factors affecting the deep burial rate of straw in a descending trend was straw coverage, deep burial depth of straw and tool advancement speed;the effect of each factor on work efficiency was the speed of implement advancement, deep burial depth of straw and straw cover;interaction in depth of straw depth and straw coverage, machine tool speed and straw coverage had a significant impact on work efficiency. After optimization, the optimal working parameters of the trenching device were achieved with deep buried rate weight of 0.7 and work efficiency weight of 0.3. The forward speed of the implement was 1.63m/s, the deep buried depth was 27.97cm, and the straw coverage was 340.54kg/hm2, the depth buried rate of straw was 90.491%, and the working efficiency was 5.4hm2/h. The analysis result showed that the optimized work effect was in line with the straw agronomy requirements. The research results can provide a theoretical reference and basis for the optimal design of trenching device for deep returning of corn straw.