农机化研究

针对现有蔬菜钵苗取投苗装置存在作业效率低、伤苗率高的问题，设计了一种夹茎式六杆取投苗装置，能够保证在不损伤钵苗的前提下实现快速取投苗。首先，基于取投苗作业轨迹关键点设计了各关键部件结构参数，并建立其运动学模型；其次，根据运动学模型使用MatLab软件编写取投苗装置的优化分析程序，分析出连杆参数对装置运动特性的影响。设定参数优化目标和约束条件，采用逐次逼近法对关键部件进行参数优化，得到一组最优连杆参数组合：l_AB=76 mm、l_BC=256 mm、l_CD=140 mm、l_AD=300 mm、l_DE=270 mm、θ₅=85~°;最后，以优化后的最优连杆参数组合设计试验样机进行虚拟仿真验证，并以苗龄45 d、基质含水率50%的茄子钵苗作为试验对象，进行样机测试。结果表明：虚拟仿真的轨迹、速度和加速度曲线与优化后理论曲线基本一致，试验样机测试的取苗成功率提升至96.83%,与传统取苗装置相比提升5.05个百分点，投苗成功率95.87%,伤苗率2.83%,能够满足蔬菜钵苗移栽机的实际作业要求。

To solve the problems of low efficiency and high damage rate of vegetable pot seedling picking and dropping device, a clamping stem six-stem picking and dropping device was designed, which could ensure quick picking and dro-pping without damaging pot seedlings. Firstly, based on the key points of seedling picking and dropping, the structure parameters of each key component were designed, and the kinematic model was established. Secondly, according to the kinematic model, the Matlab software was used to compile the optimal analysis program of seedling picking and dropping device, and the influence of connecting rod parameters on the motion characteristics of the device was analyzed. The pa-rameter optimization objective and constraint conditions was set, and the successive approach method to optimize the parameters of the key components was used to obtain a group of optimal linkage parameter combination: l_AB=76 mm, l_BC=256 mm, l_CD=140 mm, l_AD=300 mm, l_DE=270 mm, θ₅=85°. Finally, the optimized optimal linkage parameter combination design test prototype was used for virtual simulation verification, and the eggplant pot seedlings with 45 d seedling age and 50% matrix moisture content were taken as the test objects for the test prototype test. The test results showed that the trajectory, velocity and acceleration curve of virtual simulation were basically consistent with the theoretical curve after optimization. The success rate of seedling picking tested by the test prototype was increased to 96.83%, which was 5.05 percentage points higher than that of the traditional seedling pick-up device. The success rate of seedling dropping was 95.87%, and the damage rate was 2.83%, which could meet the actual operation requirements of vegetable pot seedlings transplanter.