基于ARM处理器的双加热湿度传感器设计

为消除地面气象探测领域中湿度传感器的温漂误差与沾湿误差,设计了一种双加热湿度传感器。利用24位低噪声模数转换器和电容-数字转换器实现温度和湿度的低噪声、高线性度测量,以Optidew Vision冷镜式露点仪作为标定仪器并结合遗传算法拟合修正温漂,使用交替加热的方法抑制沾湿误差。实验结果表明,该传感器的相对湿度测量精度可达±1%,并在6 min内将10%量级的沾湿误差降低至±1%。     

加热薄膜电容式气体传感器

覆盖有气体敏感层的叉指式电容器适用于微电子技术把气体传感器集成化.在加热的膜片上装配上叉指式电容器,使之温度稳定.有意义是使温度梯度横跨大面积传感器的膜.在这项工作中加热器的排列总能够保持温度均匀分布在加热的膜片上.分析的途径和有限的元件对方形膜片通常是估计加热功率分布,设计和制造试验片.制造工艺完全符合标准的双极工艺.     

用于探空仪的加热式湿度传感器及测量电路

针对探空仪湿度传感器在高空低温、高湿恶劣环境下容易结露,湿度波动大、电路板分布电容对测量结果有影响等问题,研究了具有蛇形加热器的平板夹心电容式湿度传感器及其工艺制备方法,并设计了测量电路。采用微机电系统(MEMS)加工工艺设计了加热式湿度传感器,通过对传感器进行有限元分析,确定了传感器表面加热区域温度分布情况,得出了环境温度、加热功率与加热温度三者之间的函数关系。提出一种基于电容充放电及比较法的湿度测量电路,从而有效地抑制了温度漂移和零点漂移,减小了寄生电容对测量结果的影响。地面实验结果显示:湿度传感器灵敏度约为2.3%RH·pF-1,迟滞约为0.7%F·S,重复性约为1.9%,测量总不确定度约为4%,时间常数约为0.5s。本文研究的湿度传感器及其测量电路具有很好的温度稳定性,能够在低温环境下正常工作。     

机载TFT-LCD加热系统的设计与分析

为了满足机载液晶显示器在低温环境下快速启动及正常显示的要求,对显示器进行了低温加热设计及仿真分析.首先,从理论上计算了LCD显示器所需的加热功率和加热器面电阻值.然后,建立了有限元分析模型,通过有限元分析对液晶显示器进行了低温加热仿真,得出了显示器屏组件的温度分布云图以及极值点的温度变化曲线.最后,分析了显示器温差产生的原因.结果表明,对于20.1 inch机载液晶显示器,在低温-40℃环境下,加热功率大于210 W才能保证显示器大部分区域在5 min内正常显示.     

导电加热切削最佳加热电流的确定

对导电加热切削的最佳温度及最佳加热电流进行了分析，在用 耐用度确定最佳加热电流方法基础上，提出一种基于最佳切削温度守恒定以确定最佳加热电流的新方法，该方法可迅速确定不同切削条件下的最佳加热电流，为导电加热切削过程提供了优化控制依据。     

半固态成形技术中二次加热及设备的研究

半固态铸造是一种崭新的零件成形工艺，本文主要讨论二次加热的加热工艺和设备的研制。为使二次加热最后达到整修坯料湿度差异小于2～3℃并满足一定生产率的要求，提出高频高功率升温、低频低功率热和恒温相变的加热工艺，重点论述了半固态坯料感应加热的特点和高频高功率、低频低功率中频电源的研制。提出了利用饱和变压器实现变频的方案，并依据实际研制结果进行了理论上的分析。     

激光加热时,玻璃性质的变化

提出了玻璃的结构模型，这种模型能在不同的加热方式下对其性质的发迹进行分析。分析表明，温度发迹时，玻璃性质的变化与氧原子空位浓度的温度关系相关。提出和结构相变的模拟模型对加热时玻璃性能的急剧变化进行分析。     

转盘轴承套圈感应加热间隙的自动跟踪控制

分析感应加热间隙变化对转盘轴承套圈感应淬火质量的重要影响,针对国内外转盘轴承套圈感应加热淬火设备在控制感应加热间隙方面的不足,利用非接触式位移传感器建立了基于间隙变化的闭环反馈控制系统,实现了对转盘轴承套圈感应加热间隙的自动跟踪控制,并对系统构架、检测方法、误差和信号处理进行了介绍分析。     

沉船重油电磁感应加热仿真与实验研究

针对沉船水下抽油过程中重油加热的需求,提出一种基于电磁感应原理利用油舱外板加热重油的方法,根据电磁理论及热传导理论建立了加热过程的数学模型,使用有限元软件进行数值模拟,得出重油加热过程温度衰减规律,利用油舱模型进行重油加热模拟实验,测量油舱加热过程重油温度变化及衰减规律。通过模型进行重油水下电磁加热的验证可知,实验结果与数值仿真重油加热温度变化规律有良好的匹配性。该电磁加热重油技术设备简单、加热效率较高,在防止沉船燃油泄漏领域具有较好的应用前景。     

感应加热电源的最新发展

1.引言 感应加热是通过电磁感应原理即利用涡流对被加热件进行加热。由于电磁感应加热具有加热效率高、速度快、可控性好及易于实现机械化和自动化等优点,已在熔炼、铸造、弯管、热锻、焊接和表面热处理等行业得到广泛的应用。众所周知,这些行业传统的加工方式,大多以煤、油、气为能源或箱式电炉加热,存在能耗高、劳动条件差、环境污染严     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.