依据目前影响玉米机械化收获推广普及率提升存在的多种种植行距问题,重点探讨了农机主动适应农艺的具体思路和策略,并提出了解决问题的方法和技术路径.

重点分析了农业装备产业技术的发展方向和趋势;指出了我国农业装备产业发展存在的问题和差距;提出了我国农业装备产业技术的发展方向及具体路径.

以一项新产品成功开发项目为例,阐述了产品项目成功开发需要关注的核心要素,供农机界的同仁们参考讨论和共勉.

依据我国玉米作物种植分布、生产特点以及现有玉米机械化收获作业特点和需求,指出了目前玉米机械化收获存在的问题;提出了解决玉米收获机械化问题的路径;指明了国内外玉米机械化收获技术的发展方向.

电动方向盘传动紧凑,对农业机械转向系统改动小,是农机自动导航技术的关键部件.该文介绍了基于电动方向盘的农机自动导航系统和电动方向盘结构特点,针对国内三款电动方向盘进行了扭矩-转速特性和正常工作电压性能测试,试验结果表明,三款电动方向盘电机的可控运行转速范围分别为0-200 r/min、0-109 r/min和0-100 r/min,输出功率大小为WA>WB>WC;电流大小为IA>IB>IC,其中A款电动方向盘带载能力最强.将A款和B款电动方向盘安装到拖拉机上进行了田间试验,结果表明A款和B款电动方向盘导航拖拉机跟踪直线路径的位置误差标准差分别为1.86 cm和1.60 cm,最大误差分别为-2.9 cm和2.9 cm.

电动方向盘作为农机导航系统的转向执行机构在中小型旱地拖拉机上已有应用,但在水田农业机械等转向阻力大的农机上的适应性尚有待研究.该文以井关PZ-60型水稻插秧机为平台,采用电动方向盘作为转向执行机构,对插秧机自动转向控制进行了研究.构建了插秧机转向机构的系统模型,采用系统辨识试验获得了系统模型参数.设计了基于PID的嵌套转向控制算法,采用Simulink仿真模型验证了算法的可行性.分别进行了幅值10°的正弦波、水田小角度转向(直线行驶跟踪)和水田大角度转向(调头)控制性能试验,试验结果表明:插秧机正弦波转向跟踪平均绝对误差为0.3015°,平均延时0.3 s;在泥底层平坦和不平坦的水田中直线行驶时的转向角跟踪平均绝对误差分别为0.354°和0.663°,平均延迟时间均为0.6 s,角度跟踪偏差最大分别为1.4°和3.6°,深泥脚转向阻力大时有1.4 s的控制滞后;插秧机以28°转向角调头时调节时间为2.5 s,稳态误差为0.6％.研究表明,电动方向盘转向系统具有较好的动态响应和控制稳定性,适用于插秧机作业的自动转向控制,满足插秧机自动导航作业要求.

为适应现代农机自动作业发展需求,实现插植作业和速度的自动控制,设计了水稻插秧机自动作业系统.以井关PZ-60型水稻插秧机为试验平台,研究了具有CAN(Controller area network)通信接口和手动优先的手自一体插秧机速度与插植机构控制方案,设计了插秧机专家PID速度控制算法和PID插值机构控制算法以及插秧机自动作业联合控制策略.联合导航控制系统分别在水泥路面、泥底层平坦和不平坦的水田进行了速度控制试验,结果表明,速度平均误差分别为3.25％、5.40％和8.01％,速度平均误差不超过10％的概率分别为98.6％、90.1％和68.0％;泥底层平坦水田联合控制试验结果表明,插秧机联合控制与人工操作相当,效果良好.插秧机自动作业系统满足插秧机在无人驾驶时自动作业的需求.

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">脱粒滚筒是玉米籽粒收获机的重要工作部件,影响着籽粒收获的质量。为此,设计玉米柔性脱粒滚筒,并应用NX软件进行三维建模。通过ADAMS和Abaqus分析软件进行脱粒滚筒的动平衡仿真分析、模态分析与静应力仿真分析。动平衡仿真分析结果表明该滚筒动平衡许用不平衡量符合国家相关标准,模态分析表明滚筒受到的激励频率远小于1阶固有频率避免了共振现象,静应力仿真分析表明的应力主要集中在滚筒壳体及与轴头接板连接处,但远小于材料屈服强度。上述仿真分析为后续该型滚筒的结构优化改良提供参考。</span>

农业机械自动驾驶系统是精准农业的重要支撑技术之一,集成了多种传感器与变量作业装置,助力精准农业生产降成本和增产增收,经济效益和社会效益显著.中国自2001年起对农机自动驾驶系统开展了研究,取得了一系列重大研究成果.国产农机自动驾驶系统自2010年进入市场,在降成本的同时保证了作业性能指标,摆脱了对国外进口产品的依赖.介绍了中国在农机导航定位与环境感知技术、路径跟踪控制技术、电控液压转向技术、高压共轨柴油发动机燃油电喷技术、动力换档技术、电液悬挂控制技术等方面取得的最新进展,这些研究成果为农机自动驾驶系统的研发提供了重要的技术支持.作者还提出,基于ISO11783的总线标准可实现农机自动驾驶系统的有效集成,建议进一步规范ISO11783农业机械自动驾驶系统的应用层通讯协议、线控接口和性能要求.

Based on tests,the vibration of the harvester roller caused by dynamic balance is analyzed,and the mechanical simulation model of the harvester roller is accomplished combining the theoretical analysis with the dynamics simulation software ADAMS.It is proved that the roller dynamic balancing standard is met.Therefore it provides a kind of new method for the study of dynamic balance of the harvester roller.The application of this method is to improve the precision of calculation and efficiency of design.

在合理简化的基础上,建立收割机清选装置中离心风机的CFD模型,在典型工况下对离心风机的三维流场进行了模拟分析.流场模拟的湍流模型采用k-ε两方程模型,风机旋转区域和静止区域的耦合采用MRF模型.分析结果有助于了解风机内流场的运动规律,为风机的进一步优化提供理论指导.同时对CFD分析结果进行了试验验证,计算和试验数据基本吻合,从而验证了分析结果正确,CFD分析方法合理.

A finite element model is established to the bracket of the tractor. Structure finite element of the bracket is analyzed using finite element software HYPERMESH and NASTRAN, therefore stress and position where the stress is the largest is found out in typical work status. To get the reasonable stress distribution of the bracket, the vulnerability of the bracket is given and a reasonable design of improvement is brought up, thereby the quality of products is improved and the market competitiveness is enhanced. According to results, structure of the bracket can be modified and theoretical basis is provided for the design and study of theoretical guidance.

农业装备产品作业工况十分复杂,目前产品开发过程绝大部分以物理样机的方式来验证其可靠性,这种方式最可靠,但成本高、周期长。本文用数字化设计手段,以玉米联合收获机为研究对象,建立玉米机数字化虚拟样机模型,并通过物理样机的协同测试,来调试数字化虚拟样机模型,进行多种工况的整机通过性仿真分析,根据测试结果与虚拟模型仿真计算结果相比较,判断虚拟样机建立方法的正确性。此种数字化虚拟样机仿真分析方法用于后期新产品开发中,不仅可以仿真物理样机常规试验和极端试验,而且还可以轻松获得零部件在各工况下产品设计计算的载荷谱,形成产品数字化设计重要虚拟试验方法。

To validate feasibility of chassis machine fr ame design,intensity analysis method of corn combine machine frame is studied.The method to analyze the corn combine frame intensity is studied,and the feasibility for design of chassis frame is validated.The finite element calculation model of the machine frame is modified.The comparison between the original plan and the modified plan shows that the strain distribution and intensity of the modified plan is much better and saves steel material as well.

CAE technology plays a more and more important role in company technological innovation. In our company's case, this paper reviews the method of CAE technology application and the way of company technological innovation and optimal design in large machine company.

The paper describes the CAD model assembly and the FEM assembly of working equipment of wheel loader by Using the software of NX MasterFEM.The stress analysis based on NX Nastran is done to working equipment of wheel loader and decide whether every part of working equipment can bear relevant loads or meet the working demand under the normal working conditions.

The working equipment of drilling rigs is simulated by the Finite Element software of Nastran. According to the structure characteristic, the FEM assembly of the working equipment is established by NX MASTERFEM. The static characteristic of the work- ing equipment of drilling rigs is analysed with the different load cases and status and the model analysis is done, then the blucking analysis of mast is carried out.

<正> 从2005年全国自主出口品牌建设工作会议上获悉,虽然我国已成为世界第3大贸易国,但在2005年度"世界品牌500强"中,中国只有4个。目前我国有170多类产品的产量居世界第一位,但却少有世界水平的品牌,是典型的"制造大国,品牌小国"。进入世界500强,是一种荣誉,也是世界对企业经济实力和

A computer simulation for safety experiments, including material nonlinear, geometrical nonlinear and state nonlinear, under static loads of agricultural tractor's cab is completed. The simulation process was completed according to the rule 4 Strength test method for standard guarding unit of tractors (Static load test) of OECD official standard for agricultural tractor experiment. The experimental process of back push, back press, side push, front press and front push in static loads test of tractor's cab was simulated, and the absorbed energy, the distortion and the stability state under the static loads of tractor's cab were verified. The safety of tractor's cab can be judged in the design stage by using the computer simulation. Some design mistakes can be corrected in time and the loss due to being unable to meet the safety standar of OECD can be avoided.

改革开放以来,随着我国农业机械化水平的迅速提高,联合收割机的使用越来越普遍,特别是作为一种致富的工具,越来越受到用户的重视和欢迎.而广大用户在使用联合收割机过程中时常反映"跑粮"问题,针对这个问题,多年来,我们不断深入收获现场,联系实际,和用户一起分析研究、解决问题.同时,我们又从理论分析到模拟试验,再到田间试验.经过长期对问题的分析、研究和探讨,有以下几方面的认识,仅供参考.