机载刚性支撑式快速控制反射镜设计

设计了一款紧凑型刚性支撑式快速控制反射镜(FSM),以适应机载运动平台的高振动、大冲击和高低温等恶劣工作环境。考虑机载FSM的工作需求,分别对FSM的支撑轴系、驱动元件和测角元件等进行设计与选择。针对刚性支撑轴系设计了轴系间隙调整机构,提高了FSM系统的轴系精度,进一步增大了FSM的承载能力;针对机载FSM研制了专用小尺寸微位移测量传感器,通过将4个传感器非轴线对称布置,并利用二次差分的方式实现反射镜位置的实时监测,进一步减小了FSM系统的体积,提高了它的测量精度。最后,对机载FSM的控制带宽和指向精度进行了实验检测。结果显示:所设计的FSM系统控制带宽约为110Hz,方位指向误差不超过3.4″,俯仰指向误差不超过3.8″,表明所设计的FSM控制系统稳定、响应速度快、指向精度高,满足机载运动平台的应用要求。     

具有两个双轴柔性铰链的快速反射镜设计

为了改善快速反射镜(FSM)对车载运动平台振动、冲击环境的适应性,设计了一款具有中心和四周两个双轴柔性铰链支撑结构的FSM。在明确车载跟瞄发射系统应用需求的基础上,分别对FSM的平面反射镜、驱动元件、测角元件和柔性铰链进行了详细设计和选择。采用两两差分的方法对四通道电涡流传感器的测量噪声进行抑制,有效保证了FSM的测量精度。采用有限元分析的方法对中心和四周柔性铰链的模态和刚度进行分析与优化设计,有利保证了FSM控制带宽的提高。完成FSM的精密加工、装调后,对系统的指向精度、控制带宽和阶跃响应时间进行了实验测试分析。结果表明,所设计FSM的指向精度优于1″,闭环控制带宽大于200 Hz,阶跃响应时间约为10 ms,满足车载平台系统的应用需求。     

车载激光系统光束控制反射镜角位移测量装置

为了使快速控制反射镜(FSM)能在车载、舰载等运动环境下稳定工作,并具有很高的控制精度,研制了一套高精度角位移测量装置,该装置通过精确地提供反射镜摆角信息作为系统的反馈信号来实现伺服闭环控制.针对传统快速控制反射镜位置信息反馈传感器的精度低以及不适于动载环境等缺点,采用田字裂相信号提取方法设计了基于莫尔条纹计数测量原理的精密光栅,并通过计算机进行仿真分析设计了具有抗干扰能力和耐高低温变化的绝对零位信号,其对比度达0.25.对信号处理电路进行高度集成,实现了小型化.实验结果表明,反射镜角位移测量装置测量的反射镜角分辨率为0.15″,测角精度优于0.4″,完全能满足机动式条件下,高能激光发射系统对FSM控制精度的要求.     

基于布拉格光纤光栅的微位移传感器的研究

微位移测量是目前热点研究领域,光纤布拉格光栅作为良好的传感元件,已被用于微位移测量领域。本文首先对布拉格光纤光栅传感的基本原理进行了分析,在此基础上设计制作了一种光纤光栅位移传感器。采用布拉格光纤光栅作为传感元件,利用自解调法进行波长解调,然后设计一整套传感系统,对微位移量进行了传感测量。利用激光干涉仪和PI微动平台对系统性能进行测试,实验结果显示传感系统分辨率达到50nm,系统回零重复性的误差26nm,系统的灵敏度为21mV/μm,最大非线性引用误差为2.45%。     

转台工作面角位置测量装置误差分析与补偿

针对特定转台轴端角位置检测误差不能反映实际产品工作面空间角位置的问题,介绍了一种以圆光栅和水平电容传感器作为测角元件的转台工作面空间角位置定位测量装置。以提高空间测角精度为目的,重点对装置各项误差因素进行归类分析。除光栅和传感器分别存在的分系统测角误差外,测量装置还存在转轴与测量基面不平行、传感器敏感轴与测量基面不平行等误差项。为修正测角系统误差,根据圆光栅旋转面、传感器敏感轴、转轴轴系、测量基面的空间几何关系建立数学模型,分析系统误差影响因素。最后利用分度误差在0.3″高精度转台对校准装置进行标定,并利用径向基函数(RBF)神经网络建立误差补偿模型,对系统测角精度进行修正,使系统最大误差值由13.75″下降至2.9″,满足了3″以内的测角精度需求。     

GWC100-3型光栅位移传感器的设计与应用

针对传统技术光栅位移传感器的光栅副层迭间隙小带来的调整困难、受光栅尺变形影响大、讯号质量差及做位移测量时量程比较小等缺陷,设计了一种结构新颖、调整方便和接收讯号强的新型光栅位移传感器,并成功应用于高精度数显专用测量仪.     

一种基于相位光栅干涉微位移传感器的研制

高精度微位移传感器是表面计量技术的关键技术之一.文中介绍了一种低成本、高精度的接触式微位移传感器.该传感器采用平行簧片实现精密直线运动,相位透射型正弦衍射光栅作为计量光栅实现高精密的位移测量.文中分析了其测量原理、光学原理、干涉条纹的光电接收以及辨向、细分.理论分析和实验应用结果表明该传感器垂直分辨率可达到nm级,测量量程为2 mm,可以用于微纳米表面形貌和轮廓的测量.     

快速反射镜姿态角的高精度解算

为了提高跟瞄转台出射激光的指向精度,研究了快速反射镜(FSM)姿态角与转台跟踪误差间的关系,提出了FSM姿态角的高精度解算方法。介绍了跟瞄转台出射激光的光路特点和FSM的工作原理;确定了坐标系中入射光与出射光的方向,依据坐标变换理论和光的反射定律,建立了FSM反射镜姿态角与转台跟踪误差间的函数关系。然后,推导出姿态角的解析表达式,描述了姿态角的空间分布规律,并从解析表达式中推出了近似表达式,确定了近似表达式引入的指向误差。最后,通过指向精度实验验证了姿态角解算方法的正确性。实验结果表明:在跟踪误差不超过(A 12.9′,E13.5′)时,应用姿态角解析表达式和近似表达式均能取得优于2.5″的指向精度;跟踪误差增大为(A38.6′,E37.8′)时,解析表达式对应的指向误差仍低于2.5″,而近似表达式对应的指向误差迅速增大为13.2″。得到的结果显示:FSM姿态角的解析表达式不存在原理误差,在任意跟踪误差下均能使出射激光具有高精度指向能力,且其形式简洁,满足伺服控制器快速运算的要求。     

基于MEMS加速度传感器的位移测量系统

针对运动载体位移智能化精确测量问题,基于MEMS加速度传感器设计了一种体积小、可靠性强、适用于较长距离的位移测量系统。首先分析了利用加速度进行位移测量的原理和误差,设计了加速度数值积分的多项式拟合算法,然后设计了测量系统硬件电路,最后对系统进行了直线滑轨平台测试,实验表明该测量系统位移测量最小误差可达0.3%,满足实际工程需求。     

智能刚度测量仪

本文介绍了高精度光栅位移传感器，经过对光栅输出的电信号的电路和软件细分等处理后，智能光栅传感器的测量范围２０ｍｍ，分辨率１μｍ、由位移传感器、压力传感器和测试台组成智能波纹管刚度测量仪系统。在测量系统中对由压力产生的位移误差以及压力的非线性误差进行误差补偿，提高测量精度一个数量级别，最后测量精度为２‰。刚度测量仪可以自动测量波纹管，测量时间１０秒／件，最后由打印机直接打印出所测量刚度、压力、位移的数值。     

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.