丘陵山地桑叶采收机取袋机构优化设计与试验

Optimized Design and Experiment for Bag Pickup Mechanism of Mulberry Leaf Harvesting Machine in Hilly Mountainous Area

针对丘陵山地桑叶采收机收集装置自动取袋过程实现困难的问题,通过桑叶取袋装袋过程运动学分析,对取袋机构进行了优化设计与试验.首先通过分析整机结构与取袋机构工作原理,建立了取袋机构运动学分析模型;以最大横向取袋距离和取袋瞬间角度为目标,建立了优化设计模型,并开发了辅助分析设计软件,确定了取袋机构参数的取值范围;采用带基因策略的非支配排序遗传算法(NSGA-II)对模型求解,获得最优设计参数.其次根据最优设计参数建立了三维模型,利用ANSYS进行运动学仿真分析,结果表明取袋机构末端执行器位移图像和速度曲线与设计要求一致,可满足取袋机构设计要求.最后研制出桑叶采收机与取袋机构样机,对取袋机构样机开展高速摄像试验,验证了取袋机构运动轨迹与理论仿真结果基本一致.以曲柄转速、吨口袋种类、磁吸石外圆尺寸为试验因素,取袋开袋成功率为指标开展桑叶取袋开袋正交试验,并根据最优组合进行验证试验.试验结果表明:曲柄转速为0.1 r/s、吨口袋形状与尺寸为方体550 mm、磁吸石外圆尺寸为20 mm时,取袋开袋成功率为97.50%,表明该机构能完成取袋作业,可实现桑叶采收机的取袋开袋功能.

Aiming at the problem of difficult to realize bag pickup process of collection device of mulberry leaf harvester in hilly and mountainous area,based on the kinematic analysis of mulberry leaf bag pickup and loading process,the bag pickup mechanism is optimally designed and tested.Initially,by analyzing the overall structure and working principles of the machine,a kinematic analysis model of the bag pickup mechanism was established.With the objectives of maximizing the lateral bag pickup distance and optimizing the angle at the bag pickup moment,an optimization design model was constructed.Additionally,an auxiliary analysis design software was developed to determine the parameter range of the bag pickup mechanism.The optimization process utilized a non-dominated sorting genetic algorithm(NSGA-II)with a gene strategy to obtain the optimal design parameters.Subsequently,a three-dimensional model was created based on the optimal design,and kinematic simulation analysis was conducted using ANSYS.The results demonstrated that the displacement image and velocity curve of the end effector of the bag pickup mechanism were in accordance with the design requirements,satisfying the design criteria for the bag pickup mechanism.Finally,a mulberry leaf harvester and a bag pickup mechanism prototype were developed.The bag pickup mechanism prototype was subjected to high-speed camera test,and the results verified that the bag pickup mechanism trajectory was basically the same as that of theory and simulation.The orthogonal test was carried out with crank rotation speed,the ton pocket type,the magnetic suction stone outer size as the test factors,and the success rate of bag opening as the index,and validation test was conducted according to the optimal combination.The test results show that with crank rotation speed of 0.1 r/s,the ton pocket shape and size of cube 550 mm,and the magnetic suction stone outer size of 20 mm,the success rate of bag opening was 97.50%,indicating that the mechanism can complete the bag pickup operation,and it can realize the bag opening function of the mulberry leaf harvester.