Design and Experimental Research on Seedling Pick-Up Mechanism of Planetary Gear Train with Combined Non-circular Gear Transmission

Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent transmission, and a concave and convex locking arc device, has a large rigid impact. To solve these problems, according to the design requirements for a dryland plug seedling transplanting mechanism, a rotary seedling pick-up mechanism of a planetary gear train with combined non-circular gear transmission of incomplete eccentric circular and noncircular gears was proposed. This has the characteristics of two-times greater fluctuation of the transmission ratio in a cycle, and can achieve a non-uniform continuous drive. Through analysis of the working principle of the seedling pick-up mechanism, its kinematics model was established. The human–computer interaction optimization method and self-developed computer-aided analysis and optimization software were used to obtain a set of parameters that satisfy the operation requirements of the seedling pick-up mechanism. According to the optimized parameters, the structure of the seedling pick-up mechanism was designed, a virtual prototype of the mechanism was created, and a physical prototype was manufactured. A virtual motion simulation of the mechanism was performed, high-speed photographic kinematics tests were conducted, and the kinematic properties of the physical prototype were investigated, whereby the correctness of the theoretical model and the optimized design of the mechanism were verified. Further, laboratory seedling pick-up tests were conducted. The success ratio of seedling pick-up was 93.8% when the seedling pick-up efficiency of the mechanism was 60 plants per minute per row, indicating that the mechanism has a high efficiency and success ratio for seedling pick-up and can be applied to a dryland plug seedling transplanter.

Development of single row automatic transplanting device for potted vegetable seedlings

In China,low degree of automation seriously affects the working efficiency and quality in vegetable transplanting.As one of the most important vegetables in China even in the world,tomato was taken as the research object in this study.An automatic single-row transplanting device was designed,based on the statistical analysis of the physical and mechanical properties of tomato seedlings of a typical variety.Based on the technology of mechatronics,the device integrated the functions of transporting seedling tray,automatic seedling extraction and mechanical planting.The kinematics orthogonality solution combined with the dynamic sequence solution method was used to optimize and analyze the kinematic parameters of the automatic seeding mechanism,and the“sickle”trajectory was obtained.According to the position and movement requirement for taking and dropping seedling,the mechanical conditions and the working parameters of key execution parts were obtained by using analytic drawing method to analyze the mechanical condition of seedling collecting mechanism.The transplanting experiment was conducted at room temperature of 25°C,and the age and moisture content of the seedlings were 40 d and 55%,respectively.The results showed that the highest success rate was 92.59%,and the lowest rate of leakage was 23.13%,when the transplanting frequency was 60 plants/min.The lowest success rate was 77.78%,and the highest rate of leakage was 38.75%,when transplanting frequency was 120 plants/min.When the transplanting frequency is between 60-90 plants/min,the device can meet the requirement of high speed transplanting for potted vegetable seedling.

Design and tests of a rotary plug seedling pick-up mechanism for vegetable automatic transplanter

The rotary plug seedling pick-up mechanism for vegetable automatic transplanter is the technical bottleneck to improve the mechanization level of vegetable planting in China.In order to solve the problems of rotary seedling pick-up mechanism proposed in previous study,such as low success ratio of seedling pick-up at high speed,and interference between the seedling bowl and the end of the other seedling pick-up arm,a novel kind of rotary seedling pick-up mechanism of planetary gear train with combined type gears of incomplete denatured-eccentric-circular and non-circular gears was proposed.Through kinematic analysis of the seedling pick-up mechanism,the kinematics model was established.The computer-aided analysis and optimization software with human-computer interaction method was developed to realize parameters optimization of the seedling pick-up mechanism.Three-dimensional parametric design system of seedling pick-up mechanisms with combined non-circular gear transmission was developed for mechanism virtual simulation to verify the correctness of theoretical model and design results of the mechanism.The physical prototype of the mechanism was manufactured,and high-speed camera kinematics tests of the mechanism were conducted in the laboratory to study its kinematic characteristics.Laboratory seedling pick-up tests were carried out.The mechanism has the success ratio of seedling pick-up 96.3%without interference during seedling transporting when the rotation speed of the mechanism is 50 r/min and the seedling transplanting efficiency is 100 plants/min per row,showing that the novel mechanism has better working performance than the original one and could be applied in vegetable plug seedling transplanter.

Design of Vegetable Pot Seedling Pick‑up Mechanism with Planetary Gear Train

It has been challenging to design seedling pick-up mechanism based on given key points and trajectories,because it involves dimensional synthesis and rod length optimization.In this paper,the dimensional synthesis of seedling pickup mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up mechanism.Given the positions and orientations requirements of the five key points,the study first conducted a dimensional synthesis of the linkage size and center of rotation.The next steps were to select a reasonable solution and optimize the data values based on the ideal seedling trajectory.The link motion was driven by the planetary gear train of the two-stage gear.Four pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the data.For the pitch curve with two convex points,the tooth profile design method of incomplete noncircular gear was applied.The seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter values.The results were consistent with the theoretical design requirements,confirming that the mechanism meets the expected requirements for picking seedlings up.This paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter.

Potential analysis of an automatic transplanting method for healthy potted seedlings using computer vision

Healthy seedlings transplanting is an important process in the production of vegetables and economic crops,and the transplanting quality directly affects crop yield.Automatic seedlings transplanting can improve the transplanting efficiency of seedlings.We developed a physical prototype of potted seedling automatic transplanting with a conveyor and a transplanting end-effector in the previous study.This work proposed an automatic transplanting method of healthy potted seedlings,which mainly included a detection part of seedlings growth status and a visual servo control part with the purpose of automatic transplanting seedlings high-efficiently.The seedlings and the tray cell were simultaneously detected for identifying healthy seedlings,damaged seedlings and empty cells using a machine vision algorithm when the tray was moving on the conveyor line.The visual servo model was applied to enable the collaborative operation of the machine vision and the end-effector for determining the position and attitude of grasping seedlings.The experimental results showed that the accuracy rates of the identification of empty tray cells,healthy seedling and unhealthy seedling were 96.42%,98.77%and 89.95%,respectively.Under the successful identification of the healthy seedling,the accuracy rate of grasping seedling was 96.38%.It implied that our proposed method can effectively transplant seedlings.

蔬菜泡沫育苗盘多适应性自动叠盘装置设计与试验

为了提高蔬菜育苗流水线育苗盘转运效率,针对人工取盘叠放存在的劳动强度大和整齐度偏低的问题,设计了一款针对蔬菜漂浮育苗的多适应性自动叠盘装置。该装置由机架、育苗盘输送机构、育苗盘叠盘机构和控制系统组成,装置以200Smart PLC为控制核心,利用主副传送带实现育苗盘的输送,并结合光电传感器实现育苗盘的定位,可以完成不同尺寸泡沫育苗盘的自动叠盘,设计的水平调节单元和减振单元可实现育苗盘在叠盘机构上的水平位置调节并降低叠盘过程的振动冲击。试验结果表明,育苗流水线播种环节在生产率450盘/h下,自动叠盘装置在减振弹簧线径为1.5 mm、主副传送带速度差为0.1 m/s以及电缸升降速度为0.13 m/s时,200孔穴育苗盘叠盘效果最佳,叠盘成功率为100%,叠盘错位差方差为2.32 mm^(2),同时振动检测试验中育苗盘X轴、Y轴、Z轴方向的振幅均未超过0.8 mm,更换135、160孔穴的泡沫育苗盘进行试验,叠盘成功率均为100%,叠盘错位差方差分别为3.94 mm^(2)和5.98 mm^(2),说明该装置满足多适应性的要求。在此最优作业参数下,将育苗流水线播种环节生产率提升至900盘/h时,育苗盘最大振幅为0.709 mm,振幅无明显变化,说明该装置作业稳定性较好。该研究结果可为播种流水线叠盘装置提高叠盘效果和降低叠盘振动等研究提供参考。

基于YOLO v5的直播油菜激光间苗系统设计与试验

间苗是保证直播油菜增产的一项关键技术措施,为解决人工间苗劳动强度大、机械间苗不精确的问题,采用机器视觉的方式,基于深度学习算法YOLO v5平台,设计并搭建自动间苗装置。机器视觉系统评估幼苗种群的合理密植情况,间苗算法以间距和幼苗叶展为评估标准,实现控制幼苗间距和筛选优质苗的功能。选用遗传算法对间苗行进路径进行规划,相较于未规划路径可缩短最低为50%的行进距离,最终采用激光器高温烧除的方式完成间苗作业。选取油菜苗作为试验材料,间苗阈值α是划定幼苗最小间距的参数,设置不同的间苗阈值α进行试验。结果表明,间除苗的数量随着间苗阈值α的增加而增加,幼苗平均密度下降的同时种群分布趋于均匀,对间除苗的叶展长度分类统计,α为0~75 mm时,间除苗叶展长度全部在0~20 mm范围;α为75~200 mm时,间除苗叶展长度为0~40 mm,其中叶展长度为20~40 mm的最高占比约为76%;α为200~350 mm时,间除苗叶展长度在40 mm以上的幼苗开始增加,最高占比约为14%,间除苗叶展长度梯次分布证明了间苗算法具备筛选优质苗的性能。间苗执行阶段耗时占据间苗作业总耗时的90%以上,以激光走线参数L、激光器功率P、间苗距离阈值为试验因素,三因素三水平正交试验结果表明:选择合适的激光走线参数L能有效提高间苗死亡率、降低间苗误伤率和减少间苗耗时,在参数L为30 mm、P为7.5 W、α为250 mm下开展土槽台架性能验证试验,激光间苗平均死亡率为93.29%,平均误伤率为5.19%,平均总耗时为15.19 min,为开发基于机器视觉的激光自动间苗机提供了理论基础和技术支撑。

菌草穴盘苗取投苗装置设计与试验分析

目前菌草穴盘苗移栽过程中缺乏自动取投苗装置,通过分析取投苗装置的工作原理,建立运动学模型并优化结构参数,研发一种六杆式取投苗装置。根据菌草穴盘苗钵体的抗压力学特性、取投苗装置的基本约束与空间约束,优化分析得到各杆件的结构参数,建立虚拟样机得到仿真轨迹和运动学参数。进一步研制样机,结合高速摄像技术获取取投苗装置的实际运动轨迹,对比两种轨迹的一致程度,验证装置设计的合理性。以取投“绿洲一号”菌草穴盘苗为例,将主动杆转速、送苗装置倾斜角以及钵体含水率作为试验因素,取苗成功率、投苗成功率作为响应指标,开展三因素三水平正交试验。试验结果表明,在主动杆转速为30 r/min、钵体含水率为60%、送苗装置倾斜角为50°时,取投苗的效果最优。重复试验表明,在最优因素水平下,取苗成功率与投苗成功率分别为95.31%和93.4%。

烟草钵苗双盘对称交错式自动取苗装置设计与试验

为解决烟草半移栽作业用工量大、效益低等问题,设计一种对称交错式自动取苗装置。首先,阐述该自动取苗装置对两盘钵苗进行交错式取苗的原理,建立取投苗作业过程中的动力学和运动学模型。然后,对送盘装置、取投苗装置和自动控制系统等取苗装置关键部件进行结构设计,分析关键部件的作业过程,结合实际需求完成关键元器件的选型。最后,在已有移栽机动力底盘的基础上试制2ZY-1型烟草移栽机样机,以60天苗龄的烟草钵苗为作业对象进行田间取投苗性能试验。试验结果表明,在自动取投苗速度为20株/min时,取苗成功率为89.63%,投苗成功率为97.20%,伤苗率为3.59%。

麦冬密植移栽机设计与研究

针对麦冬对种植密度要求较高、种植季节性强,且市面上已有的移栽机无法实现麦冬的密植和满栽,而采用人工栽植效率又低下的情况,设计了一种基于曲柄摇杆机构和凸轮机构耦合的自动夹取苗移栽装置。该装置可实现麦冬栽植过程中的自动取苗、栽植入土和快速推苗,栽植的株距和行距可调。试用结果显示:该装置在栽植机构每次栽16株、栽植速度1次/s的情况下,可以实现约6×10^(4)株/h的高效栽植,满足麦冬栽植的高密度和高效率的要求,提高了麦冬种植的机械化水平。

蔬菜嫁接用砧木苗位置纠偏机构试验研究

茄果类蔬菜砧木苗由于播种偏差和生长差异导致砧木苗中心偏移穴盘中心,可能在自动嫁接作业时对砧木苗造成损伤。为此,设计了一种砧木苗位置纠偏机构,通过1对拢苗手和砧木推板对砧木进行全方位约束,实现对砧木位置的纠偏。为了考察砧木苗位置纠偏机构对嫁接苗体的损伤情况,进行了砧木位置纠偏对嫁接苗体的损伤试验。结果表明:纠偏机构可以实现砧木苗偏移穴盘中心点4mm范围内的纠偏;当砧木苗向前偏移时,砧木苗位置纠偏机构“搂”回偏移的嫁接苗体的损伤率为4.9%;当砧木苗向后偏移时,砧木苗位置纠偏机构“推”出偏移的嫁接苗体的损伤率12.3%;当拢苗手和砧木推板的缓冲材料使用EVA缓冲时,没有嫁接苗体损伤;当拢苗手和砧木推板的缓冲材料使用0.3mm塑料薄膜缓冲时,嫁接苗体的损伤率为4.9%;当拢苗手和砧木推板没有缓冲材料时,嫁接苗体的损伤率为6.17%。

Design and test of soft-pot-tray automatic embedding system for light-economical pot seedling nursery machine

Most of the commercially-available pot seedling nursery machines are incompatible with soft-pot-trays and are labor-intensive and low in productivity.A soft-pot-tray automatic embedding system was developed in this study to achieve automatic embedding of the soft pot tray into the hard tray following sowing and covering with soil.A control system was constructed using the Arduino program development environment.An embedded-hard-tray automatic lowering mechanism and conveyor-belt-based pot-tray embedding system were designed.Dynamics analysis was conducted to derive an equation to describe the embedding process of the soft pot tray into the embedded hard tray.A prototype of the soft-pot-tray automatic embedding system was manufactured and tested.The analytical equation suggested that a minimum linear velocity of 0.86 m/s was required for a complete embedding process.The experimental results showed that the embedded-hard-tray automatic lowering mechanism was reliable and stable as the tray placement success rate was greater than 99%.The successful tray embedding rate was 100%and the seed exposure rate was less than 1%with a linear velocity of the conveyor belt of 0.92 m/s.The experiment findings agreed well with the analytical results.The proposed soft-pot-tray automatic embedding system satisfied the technical specifications for a light-economical pot seedling nursery machine.

直播稻苗期自动灌排系统的设计与试验

【目的】提高直播稻成苗率,依据直播稻苗期田面水分的农艺要求,设计一种适用于直播稻苗期的自动灌排系统,并验证其田间应用效果。【方法】设计适用的微喷灌溉方案和排水装置,通过LoRa通信对各设备进行无线组网控制,基于模糊控制算法制定了适用于直播稻苗期的灌排制度,从而实现自动灌排系统的各项功能;以控制系统性能指标、排水装置性能指标、苗期田面湿润状况和成苗率作为评价指标验证其应用效果。【结果】①控制系统设备动作延迟为0.398 s、系统决策时间为1.348 s、系统信息监测偏差为±1.48%;②自动排水装置启闭时间4~6 s、待机电流21.7 mA;③采用本研究的方法进行自动灌排,在苗期(播种后的15 d内)土壤水分保持在85%以上,田间成苗率达到83.9%。【结论】直播稻苗期自动灌排系统在保证高效低功耗的情况下实现了精准控制田面土壤水分,可保持田面湿润并达到合格的成苗率,有较好的田间应用效果。

烟草钵体苗自动移栽机关键部件的设计与试验

为提高烟草钵体苗移栽设备的自动化,解决现有移栽机械移栽效果不佳等问题,通过分析烟苗的表型和移栽过程,确定了自动移栽机的整机结构,对移栽机的穴盘输送装置、自动取投苗装置、柔性链输苗装置、栽植装置和覆土机构等关键部件进行了设计。利用UG、ADAMS和ANSYS软件对关键零部件开展了运动学和动力学联合仿真,以栽植频率、茎直径和栽植行走速比为试验因素,以直立度合格率和株距变异系数作为衡量指标,设计了正交试验并进行田间验证。结果表明,具备本研究所设计的移栽关键部件的烟苗自动移栽机,在栽植频率85株/min、烟苗茎直径4 mm和栽植行走速比1的最佳组合下,移栽后烟苗直立度合格率为94.42%,株距变异系数为3.25%。本研究所设计的烟草钵体苗自动移栽机可以满足烟苗移栽要求。

植物组培瓶内外壁全自动清洗机设计与试验

针对目前工厂化组培育苗生产清洗效率低、劳动强度大、使用成本高等问题,根据植物组培瓶清洗工艺要求,研制了一种植物组培瓶内外壁全自动清洗机。对关键部件进行设计和试验,确定了较佳的工作参数。试验表明,在喷淋和毛刷往复清洗次数4次、清洗时间3 s、瓶身转速150 r/min时,清洗机的平均洁净率和破损率分别为93.33%、0.83%,清洗效率960瓶/h。研制的全自动清洗机能够高效地清洗植物组培瓶的内外壁,满足工厂化生产的需求。

自动移栽机整排取苗间隔投苗控制系统设计与试验

针对自动移栽机取苗控制精度、协调配合等问题,结合自主设计的自动移栽机取苗、投苗及分苗系统结构及其工作原理,基于可编程控制器PLC设计了一种整排取苗间隔投苗控制系统。该控制系统采用3个行程开关I1、I2、I3检测翻转取苗状态,实现取苗爪针在插入苗钵过程中逐渐收缩的过程,减少了对钵体内部的损伤;运用光电传感器感应分苗杯位置和数量,以增量式编码器获取分苗杯运动位移,通过两者配合完成苗钵在最佳投苗点投苗;选用72孔和128孔穴盘、20 d苗龄的黄瓜苗进行取苗、投苗栽植试验,检测控制系统性能。试验结果表明:在栽植频率40~70株/min范围内,两种穴盘苗的取苗投苗综合成功率均高于95%,平均值为97.98%,随着栽植频率的增加,取苗投苗综合成功率有所下降,但变化不大,证明设计的控制系统能适用不同规格苗盘、不同栽植频率下的自动移栽,达到高效自动移栽目的。

蔬菜移栽穴盘苗自动输送装置设计与试验

针对目前穴盘蔬菜自动移栽中钵苗离盘转运至导苗筒过程钵体损伤大、机构轨迹复杂及机电气控制成本高等问题,设计了一种由纵向移盘机构、顶苗机构、横向移盘机构、导苗筒、夹苗机构等组成的纯机械传动式蔬菜移栽穴盘苗自动输送装置。利用功能-动作过程-动作法(F-P-A法)对穴盘苗自动输送过程进行动作分解,确定了符合各环节动作要求的机构形式;运用运动建模、仿真和精度综合分析等方法,并结合农艺与动力学要求,得出横向移盘机构圆柱凸轮最大压力角α_(max)=29.32°,夹苗机构的苗爪翻转凸轮行程hp=29 mm等关键部件参数;基于建立的时序分析模型,利用Visual Studio编写了可视化的蔬菜移栽穴盘苗自动输送装置时序分析程序,通过对各机构动作进行匹配,优选出一组最佳参数:纵移机构初始相位角φ_z=185°,顶苗机构初始相位角φ_d=108°,曲柄长度a=78mm,连杆长度b=112 mm,偏距e=20 mm,苗爪翻转机构初始相位角φ_f=15°,苗爪开合机构初始相位角φ_k=135°。以苗龄期45 d、3种不同含水率的番茄穴盘苗为试验对象,进行自动输送试验。结果表明:穴盘苗基质含水率和取苗速度对装置取苗成功率均有影响,呈负相关,基质损失率则与取苗速度关系不大;该装置能够实现140株/min的取苗速度(取苗成功率超过95%),当基质含水率为符合育苗规范的32.79%时,取苗成功率98.44%、基质损失率36.67%,满足移栽农艺要求且远超人工移栽效率。

穴盘苗自动取苗试验系统的研制

为了研究取苗器的工作过程与性能,优化取苗器的结构与运动参数,研制了针对单个穴格的自动取苗试验系统。该系统以PC机和数据采集卡为主要硬件,以LabVIEW为软件开发平台。系统具有点动和自动两种运动控制模式选择、试验参数设置、试验结果记录和分析与存储等功能,具有良好的人机交互界面,能够方便地对自动取苗过程中的位移、速度及取苗器结构参数等进行试验。系统技术参数:位移控制范围为0～100 mm,控制精度为10-3 mm;速度控制范围为0～200 mm·s-1,控制精度为10-3 mm·s-1;作用力测量范围为0～100 N,测量精度为10-5 N。试验结果表明:系统对试验参数的控制与测量具有较高的精度和灵敏性。

辣椒穴盘苗自动取苗机构运动学分析与试验

针对新疆半自动移栽机人工取苗效率低、强度大、漏苗率及伤苗率高的问题,该文设计了一种辣椒穴盘苗自动取苗机构。分析了该机构的组成及工作原理,建立了其运动学模型,研究了取苗轨迹形成的机理,在确定优化目标的基础上,基于VB开发了取苗机构辅助分析软件,结合Adams运动仿真软件,通过人机交互分析其主要结构参数变化对取苗针端点运动轨迹的影响,优化取苗针端点运动轨迹,获得一组满足辣椒穴盘苗移栽农艺要求的自动取苗机构参数。虚拟样机运动仿真结果表明优化参数可以满足辣椒穴盘苗取苗工作轨迹要求;设计制作了自动取苗试验台,并利用高速摄影技术对取苗机构运动特性进行试验分析,试验结果表明取苗针实际运动轨迹与理论分析结果一致,取苗试验结果如下:取苗成功率为98.6%,基质损伤率为4.2%,投苗成功率为94.2%,满足机械自动取苗的工作要求,验证了取苗机构设计的准确性与合理性。该研究可为辣椒、番茄等作物全自动移栽机自动取苗机构的研发提供参考。

蓝莓新梢扦插育苗设施光温湿半自动联控系统的研制

为了解决蓝莓扦插育苗的难题,该文研制了一种蓝莓新梢扦插育苗半自动联控系统,该系统在高温季节利用天然低温的地下井水,动态调控蓝莓新梢扦插育苗环境的温度、湿度和光照3种环境因子。试验表明,温度在20～35℃,控制误差小于0.15℃,相对湿度在80%～100%,控制误差小于0.2%,光照在0～16.50klx范围内,控制误差小于0.165klx。与常规蓝莓露地扦插育苗相比,该半自动联控系统下蓝莓生根时间由90d提前到25d,生根率由15%上升到高于97%,育苗周期由9个月减少到3个月,同时新苗根系质量显著提高。与组培育苗相比,平均育苗成本下降了90%,与传统育苗温室大棚及双层塑料薄膜、双层遮阳网、双层喷淋结构的育苗设施相比,显著降低了初投资和劳动强度,提高了自动化水平,育苗环境温度控制在35℃以下。