山地蕉无人机自主吊运装置研制

Development of UAV autonomous lifting and transportation equipment for mountain bananas

针对目前山地蕉采后运送作业主要依靠人工背运,存在劳动强度大、人力成本高、果实容易损伤以及易发生安全事故等问题,该研究设计了一种山地蕉无人机自主吊运装置,能够实现无人机山地蕉吊运过程中对果轴的自主抓取和卸载,减少人工参与,保障作业人员安全。基于测定的山地蕉蕉穗形态特征参数设计抓取机构、吊具、导向机构以及连接件等,并通过SOLIDWORKS软件建立装置的三维模型,同时搭建了上下位机通讯系统。基于ANSYS Workbench软件的显式动力学分析(explicit dynamics)、静磁分析(magnetostatic)对吊运装置的关键零部件进行仿真和理论计算,确定满足使用要求的电磁铁与舵机型号及参数。室内试验表明,装置的果轴平均抓取成功率为92.59%,果轴平均卸载成功率为96%,平均吊运成功率为88.89%,抓取与卸载的平均耗时分别为63.8和20.8 s/次。无人机搭载吊运装置进行田间试验,平均吊运成功率为83.33%,抓取与卸载平均总耗时90.8 s/次,平均吊运速度0.99 m/s,是人工背运速度(0.17~0.33 m/s)的3倍以上,且由于蕉穗悬空在吊运装置下方不与其他物体接触从而不会对果指造成损伤,满足无人机自主吊运山地蕉的作业需求。研究结果可为快速、低损、安全的无人机山地蕉吊运装置设计提供参考,促进香蕉产业的高质量发展。

Lifting and transportation equipment can greatly contribute to the harvesting of mountain bananas in the agricultural industry.However,some challenges still remain during post-harvest transportation,such as high labor intensity and cost,easy damage to fruits,and safety accidents.In this study,an Unmanned aerial vehicle(UAV)autonomous lifting and transportation equipment was designed to harvest the mountain bananas.The autonomous grasping and unloading of banana shafts were realized during the lifting and transportation.Manual participation was effectively reduced to ensure the safety of operators.The grasping mechanism,lifting gear,guide mechanism,and connecting parts were designed,according to the measured morphological features of the mountain banana.The specific needs were fully met by the postharvest transportation of mountain bananas.A three-dimensional model of the equipment was established using SOLIDWORKS software.The communication system of the upper and lower machines was also built.The key components of lifting and transportation equipment were simulated and theoretically calculated,using the explicit dynamics and magnetostatic analysis of ANSYS Workbench software.The parameters of an electromagnet and steering gear were determined to meet the requirements.The simulation highlighted that the better performance of equipment was achieved for subsequent testing.A laboratory experiment was then carried out to validate the efficacy of the equipment.The success rates of lifting and transportation were 92.59%,96%,and 88.89%,respectively.The average time of grasping and unloading was 63.8 and 20.8 s,respectively.The effectiveness of equipment was verified to transport the mountain bananas.Furthermore,the field experiment UAV was carried out on the lifting and transportation equipment.The success rate of lifting and transportation was 83.33%,the total time of grasping and unloading was 90.8 s,and the average speed of lifting and transportation was 0.99 m/s,which was more than three times that of manual carrying speed(0.17~0.33 m/s).Because the banana bunch was suspended under the equipment without contacting with other objects,there was no damage to the fruit finger,indicating the better quality of the fruits during transportation.Nevertheless,the equipment produced a large lateral swing on the positioning and grasping of the banana shaft,due mainly to the strong wind field under the UAV.Therefore,there were some differences between the field test and the indoor experiment,but the expected performance was achieved anyway.The structure can be further optimized to improve the success rate of lifting and transportation of the equipment for less operation time.In conclusion,the equipment can fully meet the operational requirements for the autonomous lifting and transportation of mountain bananas by UAV.Overall,these findings can provide a strong reference for efficient,low-loss,and safe unmanned lifting and transportation equipment.A reliable and efficient solution can be offered for autonomous lifting and transportation in the banana industry towards sustainable growth and productivity.