温室用小型多功能电动履带式作业平台设计

Design of small multi-functional electric crawler platform for greenhouse

针对温室果蔬管理、采运等作业环节人工劳动强度大、作业效率低,传统油动作业平台污染大、能源利用率低、结构尺寸与温室环境不符等问题,设计了一种温室用电动作业平台。该文阐述了其整体结构与工作原理,通过理论计算和 Adams/view 仿真分析等方法研究了关键部件结构及参数,并开发了一套具有双操作模式的控制系统,可实现对作业平台的远程和在线操作。通过台架试验及田间试验对作业平台不挂接拖车常规状态下的转弯性能、模拟坡面行驶倾翻性能、爬坡性能和作业续航性能等开展测试,试验结果表明:整机最小转弯半径为 0.94 m,最高行驶速度 2 km/h,200 kg 负载下作业续航时间可达 4 h 电池电量下降均匀;模拟坡面行驶最大倾翻角分别为:纵向状态 30.5°、横向状态 20.6°、斜向状态 25.6°,最大倾翻角随工作台的匀速升高、负载的均匀加重(高度随之增加)而逐渐减小,同时最大倾翻角还与作业平台和坡面的位置状态相关,纵向状态下平台作业安全系数最高,优于斜向状态和横向状态。田间试验结果表明各项指标均满足设计预期和温室结构农艺要求,该研究可为温室内果蔬管理、采摘及搬运提供参考。

At present, the tillage and seeding in the production of greenhouse fruits and vegetables have been mechanized. however, current mechanical devices are not suitable for mid-term management and transportation of viaduct cranberry fruits and vegetables. It means low efficiency and the need for more farmers, which restricts the development speed of the hole course mechanization of fruit and vegetable to produce seriously. Aiming at the problems of high labor intensity and low working efficiency in fruit and vegetable management, picking and transportation, pollution problems and so on, an electric lifting platform for greenhouse was designed based on studying and analyzing the collected data, which had the functions of walking, turning, lifting and hanging transportation. The electric lifting platform for greenhouse was mainly composed of the workbench, lifting device, chassis, battery pack and control system with dual operation mode and so on. The working principle was described, and the structure and parameters of key components were studied by theoretical calculation and simulation analysis. In particular, the control system with dual operation mode was designed to remote and online operation of the job platform, which was programmed by C language based on STC 15W4KS4 series single chip computer. In the end, the research about turning performance, slope driving and climbing performance and endurance time of the platform by the bench and field tests were carried out in the lab respectively. The test results showed that the minimum turning radius was 0.94 m, the maximum speed was 2 km/h, and the endurance time could reach to 4 h under 200 kg load. Driving on a slope, the forces analysis of platform from the slope in 3 conditions were carried out, it showed that the climbing angle was unchanged, the stability of the platform under different conditions was related to the platform weight, the loaded weight, the contact length, the lifting height, the center distance between the left and right caterpillar, and the width of caterpillar, etc. The maximum tipping angle was 30.5°, 25.6°, and 20.6° when the platform was lengthwise, crosswise and oblique to the slope respectively. The maximum tipping angle was closely related to the center of gravity of the platform. And it was gradually decreases when the height increase of workbench and loads increase. It was also closely related to the position of state platform and slope. The safety factor was the highest when the platform was lengthwise to the slope, which was better than that crosswise and oblique to the slope. When the power was above 60%, the maximum speed would always be maintained;when the remaining power was below 60%, the maximum speed would gradually decrease with the decrease of the power;when the remaining power was 40%, the endurance time was already 3.5 h;when the power was less than 40%, the power of the battery would decline rapidly;when the remaining power was 10%, the driving speed was only 0.5 km/h and the total endurance time was 3.9 h. So we could deduce that when the power was exhausted, the total duration was enough to reach 4 h. In order to evaluate the driving stability of the field slope, the cornering performance, the ground transportation performance and the lifting performance of the work table, the field experiments were carried out in Changshu, Shandong province. The results showed that all the parameters met the design expectation and the agronomic requirements of greenhouse structure. It provides a reference for fruit and vegetable management, picking and transportation in greenhouse.