Authors

Abstract

Apple tree branches have the physical characteristics of high cellulose content and high elasticity, and the use of traditional soft straw pickers will miss a large number of branches. It is necessary to design a picking mechanism that adapts to the physical characteristics of fruit tree branches. In the treatment of branches in modern orchards, the picking mechanism is an important part of the picking device. The success rate of picking directly affects the processing performance of the whole machine. To improve the picking rate, the roller branch picking mechanism is studied. The trajectory of the roller picking and the stress state of the branches are analyzed, and five main factors affecting the picking effect are obtained, i.e. the position relationship between the rotation center of the picking roller and the feeding roller, inclination angle of the steel teeth, the effective working length, the speed and the forward speed of the machine. A mathematical model is established to obtain the static and dynamic motion trajectories of the roller picking mechanism are obtained by using Matlab. Taking the analysis results of influencing factors as the optimization goal, the picking trajectory of the mechanism is simulated to obtain a set of non-inferior solutions. A roller branch picker is manufactured according to the parameter values and tested in the field, and the picking rate can reach 91%.

Abstract in Chinese

苹果树枝条具有纤维素含量高、弹性大的物理特性，使用传统的软秸秆类捡拾器进行作业会造成大量枝条漏捡的现象，因此需要设计一种适应果树枝条物理特性的捡拾机构。在现代果园枝条处理过程中，捡拾机构是机器捡拾装置中的重要组成部分。捡拾成功率直接影响着整机的处理性能。为了提高捡拾率，对辊式枝条捡拾机构展开研究。分析了对辊式捡拾运动轨迹以及枝条受力状态，得到5项影响捡拾效果的主要因素，分别是捡拾辊与喂入辊的旋转中心相互位置关系、刚性齿的倾斜角度、有效作业长度、转速和机器前进速度。建立数学模型，使用计算机编制Matlab程序获得对辊式捡拾机构的静态运动轨迹和动态运动轨迹。以影响因素分析结果作为优化目标，对机构的捡拾轨迹进行了仿真试验，获得一组非劣性解。按照参数值制造出一款对辊式枝条捡拾器并进行了田间试验，捡拾率达91%。