VIRTUAL EXPERIMENTAL ANALYSIS ON CLEANING ELEMENT OF SUGARCANE HARVESTER

The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of orthogonal experiment design, the virtual-orthogonal-experimental analysis for the cleaning element is carried out on the finite element analysis （FEA） software-ANSYS after analyzing the nonlinear structural behavior in the working procedure. The results are analyzed with the overall balancing method, and then the optimal combination is got, which is made up of different levels of different factors. Also the optimal combination of design parameters of the cleaning element received fiom the virtual experimental analysis is conducted an experiment to confirm that the virtual analysis model and results are right, and the effect of factors on the function of the cleaning element is obtained by more analysis and further optimizing.

Evaluation of Visible Losses and Damage to the Ratoon Cane in the Mechanized Harvesting of Sugarcane for Different Displacement Speeds

This study aimed at quantitatively evaluating the sugarcane losses and the damage caused to the ratoon cane while using the Case IH A8800 harvester in different displacement speeds;it was conducted in the municipality of Campos dos Goytacazes, in Rio de Janeiro, Brazil. Three speeds were used as treatment (2 km&middoth-1, 3 km&middoth-1, and 4.5 km&middoth-1), and each treatment was composed of six rows of harvested ratoon, each with a length of 290 m. In order to evaluate the quantitative losses in t&middotha-1 and the percentage of losses, the remaining sugarcane, left on the field after harvesting, was collected. The sampling frame was set to every 50 m, dividing the borders by 40 m;the measurement for each sampling area was of 20 m2, with five repetitions. In order to evaluate the damage caused to the ratoon canes, we chose a visual methodology to classify the damage degrees, ranging from one to four. There was no significant difference in losses when comparing different speeds. Therefore, it is more advantageous and economically viable to use the speed of 4.5 km&middoth-1, which collects more in less time.

Agrometeorological and Soil Criteria for Defining Workable Days for Rational Mechanized Sugarcane Harvest in Southern Brazil

The number workable days (NWD) for agricultural field operations is of great importance for sizing agricultural machinery fleets. This is especially pivotal for sugarcane harvest, which extends from 8 to 10 months/year. In light of this, the current study aimed at defining criteria for obtaining the NWD for rational sugarcane harvest at different sites in the state of São Paulo, southern Brazil, taking into account both a general and a specific criteria. For this purpose, data from harvest interruption of 30 sugar mills in southern Brazil throughout periods ranging from two to five years were used. The following variables were tested as criteria for defining harvest interruption: minimum precipitation (PREC);soil water holding capacity (SWHC);and the limit of the ratio between actual soil moisture (SM) and SWHC. Based on such a specific criterion ascribed to each site along with a general criterion, NWD maps were prepared for the state of São Paulo, Brazil. The results showed that there were variations from the definition criteria of NWD at the different sites in the state. However, the use of a general criterion for harvest interruption, based on PREC ≥ 3 mm, SWHC = 40 mm and SM/SWHC ≥ 90%, provided accurate results. During the validation of these criteria, the NWD maps generated from the individual criterion proposed for each site resulted in an average error of 24.9 days/year, whereas the map generated from the general criterion culminated in an average error of 4.4 days/year.

Influence of Cutting Stages and Sugarcane Varieties on Sucrose Content in a Brazilian Power Plant with Mechanized Harvesting

This study, carried out in a sugarcane mill located in the center-west region of Sao Paulo state, Brazil, aimed to evaluate the association of sucrose amount （POL%） with sugarcane varieties and cutting stages using mechanized harvesting. A two-way analysis of variance （ANOVA）, complemented by multiple comparison tests, was used in order to identify the effects of variety types and cutting stages on the sugarcane POL% content. An interaction between the sugarcane variety and the cutting stage was observed; therefore, both two factors cannot be independently evaluated regarding POL%. In addition, it was found that the sucrose amount from the plant production in the evaluated period presented significant differences between the cutting stages only for one variety, namely CTC2, which was different from the others in most of the cutting stages. Considering the observed results, it can be concluded that analyzing sucrose amount statistically in the mill production can allow producers to posteriorly better monitor information on the sugarcane varieties harvested under mechanized processes.

Experimental research on affecting factors of the cutting quality of sugarcane harvesters under complicated excitations

The sugarcane field excitation,cutting forces and the engine excitation constitute complicated excitations acting on sugarcane harvesters.In this study,the sugarcane cutting mechanism under complicated excitations was analyzed.The dynamics and the mathematical models of sugarcane harvesters were established and simulated.Based on theoretical analysis,sugarcane cutting experiments were done on a self-built sugarcane harvester test platform(SHTP),designed as single-factor and the orthogonal experiments.Effects of the sugarcane field excitation characterized by the sugarcane field excitation device(SFED)output frequency,the engine excitation characterized by the actuating engine output frequency,the cutter rotating speed,the sugarcane harvester travelling speed simulated through the sugarcane transporting speed of the SHTP and the cutter inclination angle on the cutting quality of sugarcane harvesters were studied.Effects of the axial cutter vibration on three-directional cutting forces and the sugarcane cutting quality(SCQ)as well as effects of three-directional cutting forces on the SCQ were further studied.It is shown that the sugarcane field excitation,the axial cutter vibration amplitude and frequency as well as the three-directional cutting forces have significantly negative monotonic correlated effects on the SCQ while the cutter rotating speed,the sugarcane harvester travelling speed and the cutter inclination angle have significantly positive monotonic correlated effects on the SCQ.Significance levels of effects on three-directional cutting forces and the SCQ form high to low are as follow,the axial cutter vibration,the sugarcane field excitation,the cutter rotating speed,the engine excitation,the cutter inclination angle,the sugarcane harvester travelling speed.The theoretical analysis results were verified through experiment and an optimal combination was obtained with the cutter rotating speed of 700 r/min,sugarcane harvester travelling speed of 0.6 m/s and cutter inclination angle of 8º.This study can provide a reference for setting cutting parameters of sugarcane harvesters with a good SCQ.

四履带式甘蔗收割机越障性能仿真与试验

目前,甘蔗主产地有广西、云南等地区,甘蔗主产区以丘陵山地为主。轮式底盘甘蔗收割机通过性差而无法在狭窄、连绵起伏等复杂坡面作业,需要一种能够适应丘陵山区的甘蔗收割机。为此,设计了一款三角履带式甘蔗收割机,底盘是由前三角履带轮和后平履带轮构成的4履带行走系统,后履带偏摆转向。同时,对该机的结构参数、履带底盘在翻越垂直壁和跨越壕沟过程中的越障性能进行分析,得出4履带式甘蔗收割机履带底盘越障性能与其结构参数的内在联系;建立了该机的多体动力学模型,在RecurDyn软件中模拟了该机在不同的参数下的动力学性能,并对样机进行越障试验验证。验证试验表明:车辆能够跨越高为18 cm的固体垂直障碍,与仿真数据相比,实际测得的俯仰角、横摆角和翻滚角的幅值变化符合预期,车辆俯仰角波动幅值超过5°,甘蔗收割机的俯仰现象明显;翻滚角变化幅值达到3°,车辆通过障碍时,需要考虑其他因素导致车辆的俯仰角变化;跨越宽为50 cm、高18 cm壕沟时,安全通过壕沟;车辆的翻滚角变化明显,幅值最大相差2°,说明此时车辆左右两边履带的颠簸较为严重,但车辆总体越障稳定性较好。研究成果可为甘蔗收割机结构设计与改进、增强作业安全性提供关键技术支持,具有重要的参考价值。

Field test and evaluation on crop dividers of sugarcane chopper harvester

In South China,the tropical weather and climate result in severe sugarcane lodging problems which greatly hinders sugarcane mechanical harvesting.The main function of the crop divider is to lift lodged canes and facilitate base-cut cane feeding.In this study,a series of field tests were conducted on crop dividers of Liugong 4GQ-180 sugarcane chopper harvester.The tests were designed to identify the relationships of the performance index(maximum lifting height of sugarcane)and the main influencing factors(machine forward speed,rotational speed of inside scrolls,and ground clearance of crop divider toes).The single factor test was conducted to determine optimum range of these test factors:the forward speed(FS)was 2.0-4.0 km/h,the rotational speed of inside scrolls(RS)was 100-140 r/min,and the toe ground clearance(GC)was 0-5 cm.The orthogonal test(three factors and three levels)was carried out to determine the optimal combination of operating parameters:FS was 2.0 km/h,RS was 115 r/min,and GC was 0 cm.In addition,the range analysis of orthogonal test results revealed that the order of each test factor affecting crop divider performance was RS,FS,GC.This study was expected to provide valuable references for the optimal operation of sugarcane harvester crop dividers.

以糖厂为主体的甘蔗机收推进模式

近年来,我国甘蔗种植面积逐年减少,切段式甘蔗联合收获机保有量大幅增加,机收率却多年低位徘徊。针对这一问题,本文从方法论视角阐明当前甘蔗产业生产关系与新质生产力之间的矛盾,是机收推进缓慢的主要原因。提出以提高甘蔗产业的竞争力和促进产业可持续发展为目标,调整甘蔗产业当前生产关系,将当前生产关系中的各方组成机收推进联合体,构建以糖厂为主体的机收推进模式。该模式以免费或低价机收为杠杆,糖厂组织、协调、管理甘蔗机械化生产,实现了糖厂有稳定优质蔗源、机收组织效益稳定、蔗农获得免费(或低价)砍收甘蔗,达到多方共赢,有利于稳定甘蔗种植面积和甘蔗产业可持续发展。以该模式为抓手,建立试点并推广应用,在当前条件下,有望打破目前机收推进缓慢僵局,实现甘蔗机收快速推进。

整杆式甘蔗收获机喂入量识别方法研究

甘蔗收获机输送系统堵塞是影响收获机工作效率的主要因素之一,而喂入量过大是导致收获机堵塞情况发生的主要原因。在甘蔗输送条件复杂情况下传统的接触式检测方法存在精度降低等问题,所以提出一种基于视觉识别检测喂入量的方法。为提高喂入量的计算精度,通过改进的SGBM算法建立三维数据模型,在优化过程中利用SIFT进行特征提取,提高算法在遮挡等复杂情况下对甘蔗的三维重建精度和鲁棒性,最后进行喂入量计算。试验结果表明,在喂入1~5根甘蔗时,改进后的算法平均体积误差分别减少3.26%、5.68%、6.32%、8.45%、7.81%,存在蔗叶遮挡时分别减少6.29%、4.24%、6.15%、12%、10.28%,该方法实现在输送样机上对甘蔗喂入量的准确识别。

甘蔗收获机多路阀阀芯的温升及热变形仿真分析

多路阀是甘蔗收获机械液压系统的核心元件,用于控制多个工作装置的协同作业。针对其阀口压差变化大,节流温升明显,易造成阀芯变形卡滞的问题,对多路阀阀芯进行了流固热耦合仿真研究。利用Design Model软件抽取对应流道,并建立不同开度的多路阀流场仿真模型,导入ANSYS Workbench平台进行不同工况下的流固热耦合仿真,分析对比了双U形和三角形节流槽在不同开度、不同进出口压差工况下,多路阀内部流场的流体速度、阀芯温度及变形的情况。结果表明:双U形、三角形节流槽阀芯最高温度始终在节流槽处;随着阀进出口压差增加,油液的最大流速以及两种节流槽型阀芯的最高温度和最大形变量增大,但三角节流槽型阀芯变形相对较小;随着阀口开度的增加,三角节流槽型阀芯温度及最大形变量均小于双U形节流槽阀芯;三角节流槽型阀芯的最大形变量较双U节流槽型阀芯小25.1%。为农业机械多路阀阀芯节流槽设计提供了理论依据。

基于遥感图像的甘蔗收割机路径规划方法

针对我国目前甘蔗收割机作业高度依赖人工操作、自主导航效率低的问题,本文提出了一种基于遥感图像特征提取技术的新颖路径规划方法。首先利用图像处理技术建立了甘蔗田遥感图像的环境模型,然后利用Floyd算法进行田间转场路径的搜索与长度计算。此外,通过将转场路径长度作为亲和度评价标准,对免疫算法进行改进,实现了多田块的遍历次序优化,进而解决了对不规则形状甘蔗田的全局路径规划问题。基于Floyd算法的改进免疫算法迭代进化最快,收敛时间最短,且能够更有效适应不同复杂程度的甘蔗田遥感图像。

甘蔗收获机切割器入土切割深度监控系统设计与试验

入土切割是降低甘蔗收获机破头率的重要方法。为了实现甘蔗收获机切割器随地面起伏自动调控入土深度,保持切割器入土深度的一致性,基于4GQ-1型甘蔗收获机,设计一种甘蔗收获机切割器入土切割深度监测与自动控制系统,实现切割器入土深度自动调控及其参数可视化,并通过室内试验和田间试验检验系统的监控性能。室内试验结果表明,监控系统的入土深度监测精度平均值为98.90%,自动控制精度平均值为97.7%,监测精度和自动控制精度达到95.0%以上。田间试验结果表明,在20、30和50mm入土深度的条件下,监控系统的自动控制精度的平均值分别是85.3%、90.6%、94.1%,自动控制精度达到85.0%以上,监控系统总体设计合理,性能良好。研究结果可为甘蔗收获机切割器入土切割深度控制系统研究提供理论参考,对甘蔗收获机优化升级具有重要的参考意义。

基于二维激光雷达的甘蔗垄高检测研究

为提高丘陵地带甘蔗收割机收割质量,研究能够跟随地形的起伏变化而调节收割刀盘高度的技术显得尤为重要,解决该问题的关键是对于蔗田地面高度的检测,因此设计一台蔗田垄高建图机器人。该机器人能适应按标准化种植的蔗田地形,通过机载二维激光雷达扫描收集蔗田地形轮廓信息,远程计算机对数据进行多维度形态学特征分析,提取蔗田数据点并建立蔗田三维地形图。仿真结果表明:该机器人能够对蔗田地形进行建图,建图分辨率为0.005 m,准确率为96.4%,为收割机的刀盘高度调节提供可靠的数据支持。

Analysis of the mechanical transfer characterization between lodged sugarcane and the cutter by simulation modeling with UMAT subroutine

Cutting the roots of sugarcane using cutters is a critical part of sugarcane harvesting,and the degree of breakage of the roots after cutting affects the germination and growth of sugarcane to a certain extent in the following year.However,the intricate interactions between the cutter and the stalk remain unclear.In order to fill this gap,this study first analyzed the conditions for no missed cuts during the operation of a double-disk cutter.Secondly,the research established a model of sugarcane stalk with anisotropy using the User-defined Material Mechanical Behavior(UMAT)subroutine based on the secondary development module of ABAQUS/Explicit.The cutting force curves obtained from simulation and test show a high correlation coefficient(R^(2)=0.9621),indicating the reliability of the model of sugarcane stalk in mechanical transfer.Subsequently,the simulation test of the blade rotating cutting characteristics in this study indicates that at a blade tilt angle of 11.3°,a blade rotating speed of 659.3 r/min,and a forward speed of 1.5 km/h,the maximum shear force on the blade is the largest,while the maximum cutting force is the smallest.Finally,based on the simulation results,this paper discussed the internal factors affecting the breakage rate of sugarcane stalks and predicted the damage location and damage force of the stalks by studying the stress wave transmission effect.Additionally,it analyzed the effects of single-knife cutting and multi-cutting on stalk incisions.The results indicated that multi-cutting causes more damage to the stalks and increases the breakage rate of sugarcane.The results of this study can provide a theoretical basis and technical reference for exploring the reduction of sugarcane residual cutting rate.

Bi-objective mathematical model for choosing sugarcane varieties with harvest residual biomass in energy cogeneration

Sugarcane crop occupies an area of about 23.78 million hectares in 103 countries,and an estimated production of 1.66 billion tons,adding to this volume more than 6%to 17%concerning residual biomass resulting from harvest.The destination of this residual biomass is a major challenge to managers of mills.There are at least two alternatives which are reduction in residue production and increased output in electricity cogeneration.These two conflicting objectives are mathematically modeled as a bi-objective problem.This study developed a bi-objective mathematical model for choosing sugarcane varieties that result in maximum revenue from electricity sales and minimum gathering cost of sugarcane harvesting residual biomass.The approach used to solve the proposed model was based on theε-constraints method.Experiments were performed using real data from sugarcane varieties and costs and showed effectiveness of model and method proposed.These experiments showed the possibility of increasing net revenue from electricity sale,i.e.,already discounted the cost increase with residual biomass gathering,in up to 98.44%.

基于麦弗逊悬架的甘蔗割铺机转向系统设计与试验

针对现有甘蔗割铺机存在转弯半径大、道路适应能力差、难适应丘陵地区地形等问题,采用麦弗逊悬架和前置液压助力转向相结合的方式,设计了一种具有高机动性的甘蔗割铺机转向系统。为了适应丘陵山地甘蔗收割作业条件,对传统麦弗逊悬架进行改造。在此基础上,建立了转向系统数学模型,通过遗传算法优化转向油缸在机架上的安装位置,使其满足阿克曼转向。然后,根据Bekker理论以及Hegedus的推土阻力估算理论分析了轮胎受力情况,并计算了转向力矩,为转向油缸选型提供依据。试验结果表明:甘蔗割铺机满足转向设计要求,最小转弯半径为2.84m;并且左前轮转向角与右前轮转向角的跟随误差均小于3.00°,试验最大转向跟随误差为2.77°,验证了麦弗逊悬架在甘蔗割铺机上的适用性及其设计的液压助力转向系统的实用性。

甘蔗收获机关键结构组成特征与技术改进

近年来,我国甘蔗机械化生产程度明显增加,耕作播种机械化普及率逐渐接近主要粮食作物,但机收率却仍明显偏低。针对甘蔗收获机在我国的应用现状与推广难点展开分析,说明了现阶段甘蔗收获机的技术特点与结构运行原理,介绍了关键工作部件的功能,并通过分析现阶段甘蔗收获机在生产应用中的不足之处提供技术优化改进建议,希望能更好促进甘蔗收获机产品升级迭代。

4GP-1A型甘蔗收获机的设计与试验

4GP-1A型甘蔗收获机是一款小型履带自走式割铺机,采用模块化设计,全液压驱动,体积小、重量轻,田间转移灵活、便捷,作业效率高,适用于南方丘陵地区小地块、行距窄的蔗地收获作业。本文详细介绍了甘蔗收获机的总体结构与工作原理,主要部件和关键技术参数设计。田间试验表明,4GP-1A型甘蔗收获机总损失率2.3%,宿根破头率6.2%,铺放角90±14°,根差210 mm,性能指标达到设计要求。

广西地区甘蔗机械化收割现状及分析

人工成本是甘蔗产业的主要成本来源之一,而收获环节的人工成本又占了总人工成本的绝大部分。机械化作业可以大大提高甘蔗收获的效率,大幅降低人工成本,因此机械化收获率的高低往往决定了产业成本的高低。广西甘蔗种植面积占全国甘蔗种植总面积的60%以上,全国排名第一,遥遥领先于其余各省。可以说,广西甘蔗机械化收割水平在一定程度上代表了我国的甘蔗机械化收割的总体水平。然而2020/2021榨季,广西地区甘蔗机械化收获率却远低于其他主要的甘蔗种植国家,这使得我国蔗糖产业的竞争力远低于其他主要的蔗糖生产国家。文章从耕地资源、规模特征、气候条件、机械化收获技术、收获设备、产业链内部矛盾等多个角度对广西甘蔗机械化收获率低的原因进行了一定的分析,并针对性地提出了一些解决的方案与措施,以期为提高广西地区甘蔗机械化收割率、降低成本、增强蔗糖产业的国际竞争力提供参考。

机械化收获对甘蔗宿根发株的影响

为了解机械化收获对甘蔗宿根发株的影响,筛选适应机械化收获的甘蔗杂交组合,通过2年5组家系试验发现,在甘蔗机械化收获过程中,收割机和收集车碾压对宿根蔗发株造成了明显的不良影响,不仅宿根蔗发株减少,而且生长势变差,当碾压程度超过4级时,其不良表现尤为突出。通过相关、线性回归分析发现,组合、时间、碾压是影响机械化收获宿根蔗发株的重要因素,评价机械化收获对宿根蔗发株的影响不仅需要调查宿根蔗发株数,还需要调查新植蔗有效茎数、宿根蔗成活情况、碾压程度和长势等性状,更重要的是选用适宜的数据分析方法才能作出有效的评价。通过计算甘蔗杂交组合耐碾压值,并选取碾压等级、宿根发株和耐碾压值进行聚类分类,从363个试验组合中筛选出11个耐碾压值高、宿根发株多的适应甘蔗机械化收获的组合。