果园采摘机械的现状及发展趋势

我国是世界第一大水果生产国,也是世界第一大水果消费国。水果种植业的迅速发展提升了果园机械的市场需求。采摘作业所用劳动力占整个生产过程所用劳动力的33%～50%,目前我国的水果采摘绝大部分还是以人工采摘为主。采摘作业比较复杂,     

螺旋式桑叶采摘机PLC控制系统的设计与仿真

结合螺旋式桑叶采摘机的工作流程,为实现该桑叶采摘机的半自动化作业,基于PLC技术,设计了一套适用于螺旋式桑叶采摘机作业的控制系统。利用PLC控制技术,再根据螺旋式桑叶采摘机的桑枝拨动、桑枝定位和桑叶采摘3个工作过程顺序,绘制了控制系统的电气原理图、功能流程图和步进梯形图。采用GX-Developer和GX-Simulator软件对该控制系统进行仿真测试,结果表明,设计的PLC控制系统能正常运行且符合设计要求。整个PLC控制系统设计简洁,使用操作便利,能实现桑叶螺旋式桑叶采摘机的半自动化作业,为减轻桑农劳动强度具有重要意义。     

枸杞采摘机的设计

为了实现机械化采摘枸杞,设计了一款智能化枸杞采摘的剪切式枸杞采摘机。主要由动力部分、伸缩部分、剪切部分和辅助部分组成;控制装置控制舵机的旋转角度使剪刀到达最佳的剪切角度,通过齿轮机构带动剪刀活动端作往复运动实现剪切作业,完成枸杞鲜果的采摘。剪切式枸杞采摘机的研究为枸杞鲜果或浆果类水果的机械化采摘提供一定参考。     

便捷的套索式水果采摘器设计

为解决现有水果采摘中存在的劳动工作量大、作业范围广、效率低下等问题,设计了一种便捷的套索式水果采摘器。该采摘器由伸缩装置、动力装置、传动装置、剪切装置和收纳装置组成,在直流电机的驱动下,由滚珠丝杆机构运动带动环形套索收缩实现采摘。理论计算确定了直流电机选型,并研制了实验样机与人工采摘和剪刀采摘进行对照实验,验证了套索式水果采摘器可以提高采摘效率,降低水果损伤率。     

双把手水果采摘收集装置设计与采摘应用分析

为了灵活高效的采摘高枝带梗水果,提供了一种可以同时采摘水果和收集水果的装置。装置通过设置双把手来分别操控采摘头转头、旋转、抓取,提高了采摘效率;通过设置转头装置和旋转装置改进了采摘方法;通过设置水果缓冲收集装置实现了水果无伤收集;通过设置地面支撑装置提供了支撑力。装置主要应用于苹果、梨子等水果采摘,适用于现阶段果农的使用。     

一种新型剪切式木本水果采摘器的设计

为解决水果高枝采摘难和水果采摘器单一采摘的问题,设计一种新型实用的剪切式木本水果采摘器。设计分线结构来达到开始工作时间稍微错开的目的。不损伤水果表皮为前提,以产生平衡剪切枝条时的力和力偶为目的,设计气囊夹持机构,并通过对不同果皮类型的水果比较分析确定一个气压中间值。该新型采摘器有效提高了对生长在高枝的木本水果采摘作业的效率,解决了多种木本水果统一采摘的问题。     

辅助人工便携式水果采摘器

水果的大量生产和投放市场丰富了人民的膳食品种,全国很多地区在水果的采摘上依然主要靠人工,采摘中存在劳动工作量大、作业范围广、触碰力度控制要求高等问题。针对水果采摘存在的问题,我们提出了一种辅助人工便携式水果采摘器。该装置主要由电动旋转采摘头、可控复合伸缩杆、电动开关、减速网兜、折叠收果小车五部分组成。该装置结构简单、成本低廉,适用于大部分果园采摘,减少劳动强度,提高采摘效率。     

基于虚拟样机技术的水果采摘机器人设计

分析了目前国内水果采摘机器人的结构特点,提出了一种球形水果采摘机器人的总体结构方案,并采用虚拟样机技术重点设计了机器人的行走机构和末端执行器.在UG环境下建立了机构的虚拟样机模型,然后通过UG和ADAMS良好的接口直接导入ADAMS,实现了机器人机构的运动学性能仿真分析.该机器人的主要特点是能够适应恶劣的地面环境、对果实伤害小、采摘效率高,能够为进一步研究开发实用型水果采摘机器人提供基础.     

一种苹果采摘筛选机设计

设计一种协助果农采摘和筛选苹果的采摘筛选机。该设计采用双减速电机、履带底盘和万向轮实现行驶功能,采用无线六位遥控模块M6CZS进行遥控控制。通过双电机双侧驱动,双齿轮齿条啮合传动实现升降台升降作业。执行器采用六个舵机搭载机械手,利用飞思卡尔MC9S12XS128单片机控制,实现空间多姿态采摘作业。智能化采摘苹果,降低了苹果的损伤率,快速高效多样化的采摘果实,大幅度的提高了效率。     

一种高枝水果采摘头的设计分析

为解决目前高枝水果采摘的人工采摘方式存在的效率低、劳动强度大、安全性低等问题,设计了一种可连续采摘多枝条的新型高枝水果采摘头.采摘头主要包括喂入机构、导向夹持机构、剪断收集机构、支撑板及配件等.通过喂入机构利用棘轮机构的单向性和间歇性,将水果枝干间歇地送进夹持导向机构.再经过剪断机构将水果枝干逐步剪断并保存在收集机构上,实现多枝采摘的过程.经过对关键机构部件的设计计算、仿真分析、样机制作和试验分析,表明所设计的采摘头结构合理,强度满足要求,能够有效将高枝水果枝干间歇喂入、连续剪断和多串收集,防止水果串掉落损坏,效率高、安全性好.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.