摇枝式加工型苹果采摘振动参数仿真优化与试验

为探究不同振动参数组合对苹果采摘效果的影响，建立苹果树二级树枝振动力学模型，解析分析得到影响苹果脱落的主要因素为振动频率、振幅及夹持位置。测量苹果树形态特征并基于矮砧密植整形原理建立纺锤形苹果树三维模型，利用ANSYS软件对苹果树模型进行有限元仿真分析，仿真结果表明，振动频率4~8Hz、振幅20~30mm、夹持位置0.35l~0.65l（l为二级树枝长度）时，对果树损伤较小且苹果易脱落。设计四因素三水平振动采摘试验，以确定苹果树不同位置树枝最佳的振动参数组合，利用Design-Expert软件对试验数据进行分析和响应面优化，参数优化结果为：采摘苹果树上层苹果时，振动频率为5Hz，振幅为28mm，夹持位置为0.40l；采摘苹果树中层苹果时，振动频率为4Hz，振幅为30mm，夹持位置为0.43l；采摘苹果树下层苹果时，振动频率为8Hz，振幅为20mm，夹持位置为0.65l；通过验证试验得到苹果树上层、中层、下层摘净率为96.4%、94.8%、93.2%，与优化值相近，表明优化模型可靠。

Simulation Optimization and Experiment of Vibration Parameters of Apple Picking by Shaking Branch Processing

In order to investigate the influence of different positions of apple tree branches on the picking effect under different combinations of vibration parameters, the main factors affecting the apple drop were obtained as vibration frequency, amplitude and holding position through the establishment of a secondary branch vibration mechanics model of the apple tree and analytical analyses. Measuring the morphological characteristics of apple trees and based on the principle of dwarf anvil dense planting shaping to establish a three-dimensional model of fusiform apple trees, using ANSYS software to carry out finite element simulation analysis of the apple tree model, the simulation results showed that the vibration frequency of 4~8Hz,amplitude of 20~30mm, the holding position of 0.35l~0.65l (l was the length of secondary branches), the damage to the fruit tree was small and easy to fall off the apples. In order to determine the best combination of vibration parameters for different positions of branches in apple trees, a four-factor, three-level field experiment was designed, and the experimental data were analyzed and response surface was optimized by using Design-Expert software, and the results of the parameter optimization were as follows: when picking apples on the upper layer of the apple tree, the vibration frequency was 5Hz, the amplitude was 28mm, and the clamping position was 0.40l. When picking apples in the middle layer of the apple tree, the vibration frequency was 4Hz, the amplitude was 30mm, and the clamping position was 0.43l; when picking apples from the lower layer of the apple tree, the vibration frequency was 8Hz, the amplitude was 20mm, and the clamping position was 0.65l; it can be seen through the validation test that the picking rates of the upper to the lower layer of the apple tree were 96.4%, 94.8%, and 93.2%, which were similar to the optimized values, indicating that the optimized model was reliable.