Coupling Analysis of Moment of Inertia & Dynamic on Optoelectronic Tracking Turntable

With photoelectric tracking system as the research object,based on the theorem of moment of momentum and Euler dynamic equation,Nonlinear biaxial coupling dynamic model of tracking turntable is established.Effects of moment of inertia coupling,speed coupling and the dynamic coupling between tracking turntable shafts were studied,the analytical relation between them was given in theory.Verify the change trend of theoretical model.And it provides the theory reference and model base,for the future design of the high precision tracking controller And control parameter selection and optimization.In the end,specific measures are made for structure optimization.

Electronic image stabilization system based on global feature tracking

A new robust electronic image stabilization system is presented, which involves feature-point, tracking based global motion estimation and Kalman filtering based motion compensation. First, global motion is estimated from the local motions of selected feature points. Considering the local moving objects or the inevitable mismatch, the matching validation, based on the stable relative distance between the points set is proposed, thus maintaining high accuracy and robustness. Next, the global motion parameters are accumulated for correction by Kalman filteration. The experimental result illustrates that the proposed system is effective to stabilize translational, rotational, and zooming jitter and robust to local motions.

A New Simulation of Track Structure of Low-Energy Electrons in Liquid Water:Considering the Condensed-Phase Effect on Electron Elastic Scattering

A new Monte Carlo simulation of the track structure of low-energy electrons （〈10keV） in liquid water is presented. The feature of the simulation is taken into consideration of the condensed-phase effect of liquid water on electron elastic scattering with the use of the Champion model, while the dielectric response formalism incorporating the optical-data model developed by Emfietzoglou et al. is applied for calculating the electron inelastic scattering. The spatial distributions of energy deposition and inelastic scattering events of low-energy electrons with different primary energies in liquid water are calculated and compared with other theoretical evaluations. The present work shows that the condensed-phase effect of liquid water on electron elastic scattering may be of the influence on the fraction of absorbed energy and distribution of inelastic scattering events at lower primary energies, which also indicate potential effects on the DNA damage induced by low-energy electrons.

汽车电子节气门系统无抖振滑模控制方法研究

针对电子节气门(ET)系统非线性特性对节流阀控制精度的影响,提出了一种鲁棒自适应无抖振滑模控制(ACFSM)方法。该控制方法考虑了ET系统非线性和参数不确定性的影响,引入了遗传算法(GA)优化了ACFSM控制器的控制参数获得了平滑的控制信号,结合所设计的自适应控制律减轻了不确定性的影响。为验证所提控制方法的有效性,通过实验表明ASCFM控制器不仅在闭环系统响应中不存在抖振现象,而且可以很好地保持良好的瞬态和稳态跟踪性能。通过对比表明ASCFM控制器在跟踪性能上优于ASM控制器,尤其在节流阀遇到外部干扰时,所提出的ASCFM控制器具有较强的鲁棒性。

变电站内SF_(6)分解物检测追踪系统设计

六氟化硫(SF_(6))气体分解与泄漏现象日趋严重,给电气设备的绝缘性能带来了严重的负面影响,甚至对电气设备在运行过程中的安全性产生了极大的威胁。为快速有效地对SF_(6)气体的分解物(二氧化硫SO_(2)、硫化氢H_(2)S等)进行检测并定位泄露源,该研究基于高级精简指令集计算机(advanced RISC machine,ARM)控制器设计了可以检测以上两种主要有毒气体的电子鼻系统。接着以模拟退火算法为基础,提出气体烟羽追踪方法,旨在解决气体泄露源定位问题。气体浓度检测实验表明,相比MX6商业电子鼻,该文自制的电子鼻系统的气体浓度检测相对误差在0.7×10^(-6)以内,可以有效地检测以上两种有毒气体。此外,考虑到以上气体具有毒性,以乙醇气体为气味源进行了气体烟羽追踪实验。结果表明,该文所提出算法的有效性和实时性较好,平均定位误差只有0.63 m。以上实验证明该设计的电子鼻及模拟退火算法能够满足移动机器人进行SF_(6)分解气体泄漏检测的应用需求。

面向电子装备装配引导的AR跟踪方法研究

为了提高面向电子装备装配引导的增强现实(augmented reality,AR)跟踪方法的鲁棒性与适用性,在像素投票姿态估计网络结构的基础上,结合深度可分离卷积和通道注意力机制对AR跟踪算法进行优化。首先,针对电子装备六自由度姿态公共数据集稀缺与使用约束较多的问题,使用RGB-D相机采集并制作AR装配引导的电子装备的六自由度姿态训练数据集。然后,在基于像素投票的姿态估计网络结构基础上,使用深度可分离卷积对网络进行轻量化,并引入通道注意力机制对通道进行权重评估,以弥补网络轻量化造成的精度损失。最后,通过电子装备装配任务对提出的方法进行AR装配引导验证。实验结果表明:提出的跟踪注册方法相对于修改前的跟踪方法具有较好的鲁棒性,同时保持了装配引导的精度,能够对弱纹理的电子装备进行跟踪。

小微企业会计档案电子化单轨制管理探析

随着相关法律、法规的落地,电子化单轨制管理已是未来会计档案管理的主流,部分企业已试点成功,但在小微企业中未普及。文章认为,缺少动力、缺乏资源和代理记账机构数据不互通是主要原因。提出通过政府购买服务建立业、财、档共享服务中心,整合资源,为小微企业提供集业务、会计、档案为一体的服务,推动会计档案电子化单轨制。

全电子执行单元冗余供电研究

针对高原铁路全电子执行单元系统供电问题,该文提出2种高可靠性的供电方案。第一种方案是在电源屏上新增一路直流转换模块,为执行单元提供独立的额外供电,即直流双路直供方案。第二种方案是在保持电源屏供电方式不变的基础上,将执行机柜的单断路器升级为双断路器,通过2台执行机柜的互环连接,实现用电的冗余,即执行机柜互环供电方案。这2种方案的目标都是提升全电子执行单元用电的可靠性和稳定性。综合比较,执行机柜互环供电方案在高原铁路执行单元电源改造中更加具备可行性。该文的研究对高原铁路全线全电子执行单元供电方式的改造具有指导意义。

数据保全视角下建设项目电子文件单轨制管理模式研究

电子文件与电子档案的管理是项目信息化的重要组成部分,本文以合肥水源工程为案例,从数据保全的视角出发,探讨了建设项目电子文件单轨制管理模式的构建与应用。通过对数据保全概念的解读,建立了电子文件单轨制管理模式的理论框架,并在实际工程中应用了电子签章技术和数据化管理方法,以保障电子文件的真实性、完整性、可用性和安全性。研究结果为建设项目电子文件管理提供了有益的经验,推动建设项目信息化管理水平的提升。

光伏和风电一体化系统中的电源管理与电子电路设计

光伏和风电一体化系统可以提高可再生能源的利用效率,降低能源成本。文章重点探讨了该系统中电源管理与电子电路设计的关键技术。针对最大功率点跟踪(Maximum Power Point Tracking,MPPT)算法,比较了传统方法与基于机器学习的新型算法,并评估了其性能指标。在并网逆变器设计和储能系统集成方面,深入分析主要拓扑结构、关键参数优化以及经济性。通过一个典型工程案例,评估了系统整体性能和经济环境效益。该研究为光伏和风电一体化系统的优化设计提供了重要技术支持。

Effect of biased estimation on radar-to-ESM track association

The track association problem of radar and electronic support measure （ESM） has been considered in the literature for several years. This problem is crucial for radar-to-ESM track fusion and is complicated by the presence of individual systematic errors and measurement errors. In order to improve the track association of radar and ESM sensors, a pseudo-linear filtering algorithm is proposed to estimate the target states and improve the stability of the filter. It is found that, however, the correct probability of radar- to-ESM track association decreases as the radar measurement error decreases, when the pseudo-linear filter is used for ESM sensor filtering. In view of the strange phenomenon, this paper analyzes the reason for it by using the statistic theory and further performs Monte Carlo simulation to verify the analysis.

Effective energy deposition and latent track formation of swift heavy ions in solids

In the present paper, latent track formation in yttrium iron garnet (YIG) produced by high energy Ar ions is briefly reported at first. Then, in the framework of thermal spike model, a phenomenological parameter describing the effective energy transfer from excited electrons to lattice atoms, effective energy deposition Qeff, is deduced. Qeff is a function of ion velocity, electronic energy loss (Se) and mean free path λ of excited electrons in the matter, and is a time moderate term initialized by Waligorski’s function of spatial energy deposition of secondary electrons ejected by incident ions. Size of ion latent track is proportional to Qeff value. From Qeff obtained by use of realistic λ values, the sizes of latent tracks in SiO2, YIG, Ti and Zr produced by given swift heavy ion irradiations are deduced and com- pared with experimental results. It is found that, from the fits to experimental results, the best λ values for SiO2, YIG, Ti and Zr are (6±1), (8±2), (6.1±1.0) and (9.6±1.0) nm, respectively. Moreover, the relationship between experimental damage and Qeff is discussed.

Posterior Cramer-Rao lower bounds for bearing-only tracking

In the state estimation of passive tracking systems, the traditional approximate expression for the Cramero-Rao lower bound （CRLB） does not take two factors into consideration, that is, measurement origin uncertainty aad state noise. Such treatment is only valid in ideal situation but it is not feasible in actual situation. In this article, considering the two factors, the posterior Cramer-Rao lower bound （PCRLB） recursion expression for the error of bearing-only tracking is derived. Then, further analysis is carried out on the PCRLB. According to the final result, there are four main parameters that play a role in the performance of the PCRLB, that is, measurement noise, detection probability, state noise and clutter density, amongst which the first two have greater impact on the performance of the PCRLB than the others.

Current progress of study on gas electron multiplier

Recent progress of study on gas electron multiplier (GEM) has been described. Due to its fast time re-sponse and excellent position sensitivity, the GEM will find wide applications in particle physics, medicine and as-trophysics. These potential applications have been briefly introduced.

Method of temperature rising velocity and threshold control of electron beam brazing

In order to accommodate electron beam to the brazing of the joints with various curve shapes and the brazing of thermo sensitive materials, the method of electron beam scanning and brazing temperature control was developed, in which electron beam was controlled to scan according to predefined scanning track, and the actual temperature rising velocity of the brazed seam was lim- ited in an allowed scope by detecting the brazed seam temperature, calculating the temperature rising velocity and adjusting the beam current during the brazing process; in addition, through the setting of the highest allowed temperature, the actual temperature of the brazed seam could be controlled not exceeding the threshold set value, and these two methods could be employed alone or jointly. It is shown that high precision temperature control in electron beam brazing could be realized and the productivity be increased by the proposed method.

电动拖拉机PC-DSPM电机电子变极策略与分析

针对田间作业和转场运输等不同工况时的行驶速度需求,该研究提出使用双凸极变极永磁(pole-changing doubly-salient permanent magnet,PC-DSPM)电机作为电动拖拉机的驱动电机,通过变极获得驱动电机的多种机械特性。基于气隙磁场调制理论,将PC-DSPM电机气隙磁场中的主要工作谐波分为2组,采用电子变极改变电枢绕组连接方式,从而选择不同组别的气隙磁场谐波参与机电能量转换,形成PC-DSPM电机3种运行模式。根据不同模式下的转矩-转速曲线,选取电机在恒功率区的2个变极切换点,并据此将拖拉机的运行速度划分为0~7.7、7.7~10.5和10.5~32.7 km/h共3个区间。为实现平滑变极,构建自抗扰控制和跟踪微分器的PC-DSPM电机变极策略。与采用自抗扰控制的阶跃响应变极相比,虽然2个切换点处的变极时间分别延长至400和600 ms,但变极过程中dq轴电流过渡平稳,转矩波动分别下降8.5%和11.8%,转速恒定在920和1 250 r/min。研究结果可为实现电动拖拉机多工况高效运行及变极永磁电机平滑切换提供理论参考。

高性能有机硅密封胶的研究

电子元器件向着微型化、高集成化方向发展,对有机硅密封胶的性能提出了新的要求。为了提高其粘结强度、阻燃性能、机械性能和电气绝缘性能,以γ-(2,3环氧丙基)丙基三甲氧基硅烷(KH560)和羟基丙烯酸酯改性MQ硅树脂制得硅烷聚合物为增粘剂,乙烯基硅油为基料,含氢硅油为交联剂,气相白炭黑、硅微粉和氢氧化铝为补强材料,铂金复合体系为催化抑制剂,制备了有机硅密封胶,并研究不同组分对密封胶性能的影响。研究结果表明,当硅乙烯基∶硅氢的摩尔比为1∶1,MQ硅树脂的添加量为20%(以乙烯基硅油的质量分数为基准,下同)、增粘剂为1.5%、气相白炭黑为6%、硅微粉为20%、氢氧化铝为30%时,制备的有机硅密封胶综合性能优异,其剪切强度为4.72 MPa,拉伸强度为4.91 MPa,断裂伸长率为146%,阻燃性能达到V-0级,相比电痕化指数为600 V,完全可以满足电子元器件的发展对密封胶新的技术要求。

汽车电子节气门RBF神经网络控制方法

针对汽车电子节气门模型参数不精确和外界干扰等不确定条件下的控制问题,提出了一种RBF神经网络控制方法,解决传动控制方法需要精确建模的问题。首先,对电子节气门的工作特性进行分析,并充分考虑参数不精确和外界干扰等不确定性,建立其数学模型的状态空间表达形式。而后,基于传统滑模控制理论,提出了抗外部干扰的滑模控制方法。进而,利用RBF神经网络对控制器不确定部分进行在线逼近,提出一种局部逼近的神经网络控制方法,并通过Lyapunov方法证明了控制系统的稳定性。最后,基于Matlab/Simulink平台进行对比仿真实验。实验结果表明,所提控制方法能够有效克服外部干扰以及模型参数带来的不确定性,实现电子节气门实际开度对目标开度的精确跟踪。

网页搜索列表产品图片复杂度对用户注意的影响研究-基于眼动数据的分析

在网络购物中,消费者会根据搜索列表中产品图片信息对商品进行评估和筛选,如何提高商品被点击概率是每个商家考虑的重要问题。许多商家设计产品图片如编辑图文信息和色彩等提高产品图片复杂度以提高产品点击率。现有研究认为视觉复杂度是影响用户认知和行为的关键因素。在网页搜索列表情境下,产品图片的视觉复杂度如何影响用户注意等决策行为存在诸多研究空白。本文从元素复杂度和色彩复杂度两个维度考察了在搜索结果列表页面中产品图片复杂度对消费者注意的影响作用。研究设计3(元素复杂度低、中、高)×2(色彩复杂度低和高)被试内眼动实验收集数据,运用重复测量方差分析进行数据处理。结果表明,相对于中、低元素复杂度的产品图片,被试对高元素复杂度情况下的产品图片的注视次数和注视时长显著提升;相对于低色彩复杂度的产品图片,被试对高色彩复杂度的产品图片的注视次数和注视时长显著提升。本研究扩展了视觉复杂度理论,将色彩复杂度和元素复杂度结合,共同探讨了在网页搜索结果列表新情境中产品图片复杂度对消费者注意的影响作用。本研究为网购页面产品图片设计和管理实践提供了理论指导和设计策略。

Adaptive Sliding-Mode Control of an Automotive Electronic Throttle in the Presence of Input Saturation Constraint

In modern vehicles, electronic throttle(ET) has been widely utilized to control the airflow into gasoline engine. To solve the control difficulties with an ET, such as strong nonlinearity,unknown model parameters and input saturation constraints,an adaptive sliding-mode tracking control strategy for an ET is presented. Compared with the existing control strategies for an ET, input saturation constraints and parameter uncertainties are adequately considered in the proposed control strategy. At first, the nonlinear dynamic model for control of an ET is described. According to the dynamical model, the nonlinear adaptive sliding-mode tracking control method is presented,where parameter adaptive laws and auxiliary design system are employed. Parameter adaptive law is given to estimate the unknown parameter with an ET. An auxiliary system is designed,and its state is utilized in the tracking control method to handle the input saturation. Stability proof and analysis of the adaptive sliding-mode control method is performed by using Lyapunov stability theory. Finally, the reliability and feasibility of the proposed control strategy are evaluated by computer simulation.Simulation research shows that the proposed sliding-mode control strategy can provide good control performance for an ET.