基于DEM-MBD的变螺距式马铃薯分级装置设计与试验

Design and Experiment of Variable Pitch Potato Grading Devices Based on DEM-MBD Coupling

摘要:

为解决马铃薯分级装置结构较大、传动复杂、易伤薯问题，设计了一种变螺距式马铃薯滚筒分级装置，明确了其工作原理，通过对马铃薯在分级装置内的动力学和运动学分析确定了其关键结构参数。运用RecurDyn软件构建分级装置动力学模型，基于马铃薯的物理特性在EDEM中构建马铃薯模型，采用EDEM-RecurDyn耦合仿真模拟了分级装置实际工作过程中多构件间的运动、约束和接触。选择进薯量、分级滚筒转速和分级段长度为影响因素，以马铃薯分级准确率、分级效率作为评价指标进行性能验证，并基于上述因素进行单因素与二次正交仿真试验，确定分级装置的最优结构和运动参数。仿真试验结果表明，当进薯量为3.68kg/s、分级滚筒转速为34.50r/min、分级段长度为1600mm时，所获得的分级准确率和分级效率最优，分别为91.6%和3.0kg/s。样机试验结果表明，在最优解参数下分级装置平均分级准确率大于89%，平均分级效率大于3.18kg/s，伤薯率小于1%，与仿真试验相对误差为2.10%，说明仿真试验具有较高准确性且本文设计的分级装置工作性能较好，可以满足中小规模的马铃薯分级要求。

Abstract:

In order to solve the problems of potato grading device with large structure, complex transmission and susceptibility to damage potatoes, a variable pitch potato grading device was designed, and its working principle was expounded. The key structural parameters of the potato were determined by dynamic and kinematic analysis of the potato in the grading drum. The dynamic model of the grading device was constructed by using RecurDyn software. The potato model was constructed in EDEM based on the physical characteristics of potato. The EDEM-RecurDyn coupling simulation was used to simulate the movement, constraint and contact between multiple components in the actual working process of the grading device. The amount of potato, the rotation speed of the grading drum and the length of the grading section were selected as the influencing factors, and the potato grading accuracy and grading efficiency were used as the evaluation indexes to verify the performance. Based on the above factors, the single factor and quadratic orthogonal rotation regression combination simulation test was carried out to determine the optimal structure and motion parameters of the grading device. The simulation results showed that the amount of potato was 3.68kg/s, the speed of the grading roller was 34.50r/min, and the length of the grading section was 1600mm, the optimal values of the classification accuracy and classification efficiency obtained were 91.6% and 3.0kg/s, respectively. The prototype test results showed that the average classification accuracy of the grading device was greater than 89% under the optimal solution parameters, the average classification efficiency was greater than 3.18kg/s, and the potato injury rate was less than 1%. The relative error between the simulation test and the prototype test was 2.10%, indicating that the simulation test had high accuracy and the grading device designed had good working performance, which can meet the requirements of potato grading in small and medium-sized farms.