【摘要】 针对玉米大田机械除草机除草效率低、伤苗率高等问题，设计一种立式双轴对旋除草机。对玉米大田土壤及常见杂草的物理特性进行测定分析，利用EDEM软件建立根土复合体离散元模型；对除草刀与除草过程中土壤和草根的互作关系进行仿真，评估不同参数对除草刀除草功耗和除草性能的影响；以斜切角、端切角和刀片数量为影响因素，除草扭矩和碎土率为响应值，通过预试验和单因素试验确定各因素对响应值的影响规律，基于前期仿真试验结果开展多因素仿真试验并基于非支配排序遗传算法（NSGA-II）对除草刀进行优化，得出最佳除草刀参数；通过田间试验验证除草刀在实际作业中的可靠性。优化得到除草刀最佳参数组合为，斜切角10°、端切角55°、刀片数量3片；以最佳参数组合进行田间试验验证，除草率为94.67%、伤苗率3.74%、碎土率84%，除草机作业期间运行稳定，具有良好的除草效果。更多还原

【Abstract】 To address the issues of low weeding efficiency and high seedling damage rates of maize field conventional mechanical weeding machines, a vertical double-shaft counter-rotating weeding machine was designed. The physical properties of maize field soil and common weeds were measured and analyzed, and the root-soil composite discrete element model was established using EDEM software. The interaction between the weeding knife and the soil and weed roots during the weeding process was simulated to evaluate the effects of different parameters on the power consumption and performance of the weeding knife. Using blade inclination angle, end face inclination angle, and the number of blades as influencing factors and weeding torque and soil crushing rate as response variables. Pre-experiments and single-factor experiments were conducted to determine the influence of each factor on the response variables. Based on the results of prior simulation experiments, multi-factor simulation experiments were carried out, and the weeding knife was optimized using the Non-Dominated Sorting Genetic Algorithm-II( NSGA-II) to determine the optimal parameters of the weeding knife. Field experiments were conducted to verify the reliability of the weeding knife during actual operations.The optimal parameter combination for the weeding knife, obtained through optimization, was a blade inclination angle of 10°, an end face inclination angle of 55°, and 3 blades. The results of field trials conducted with the optimal parameter combination showed that the weeding rate was 94. 67%, the seedling injury was of 3. 74%,and the soil crushing rate of 84%, respectively. In conclusion, the weeding machine operated stably during the process and exhibited good weeding performance.更多还原