无介质硅压阻式压力/压差传感器的研制CSCD

目前,硅压阻式压力/压差传感器在伺服系统上得到广泛的应用。但是由于其内部压力敏感芯体的封装结构为薄膜隔离式,其内部硅油的密封性是伺服系统配套传感器长期带压贮存的软肋。根据伺服系统对压力/压差传感器的需求,研制了几种无介质压阻式压力/压差传感器,其内部避免了硅油介质传递压力,保证了传感器的可靠性。通过传感器原理结构的研究,以及其性能指标的测试和对比,为伺服系统配套传感器提供了新的选择。     

The legacy of Biosphere 2 for the study of biospherics and closed ecological systems.

The unprecedented challenges of creating Biosphere 2, the world's first laboratory for biospherics, the study of global ecology and long-term closed ecological system dynamics, led to breakthrough developments in many fields, and a deeper understanding of the opportunities and difficulties of material closure. This paper will review accomplishments and challenges, citing some of the key research findings and publications that have resulted from the experiments in Biosphere 2. Engineering accomplishments included development of a technique for variable volume to deal with pressure differences between the facility and outside environment, developing methods of atmospheric leak detection and sealing, while achieving new standards of closure, with an annual atmospheric leakrate of less than 10%, or less than 300 ppm per day. This degree of closure permitted detailed tracking of carbon dioxide, oxygen, and trace gases such as nitrous oxide and ethylene over the seasonal variability of two years. Full closure also necessitated developing new approaches and technologies for complete air, water, and wastewater recycle and reuse within the facility. The development of a soil-based highly productive agricultural system was a first in closed ecological systems, and much was learned about managing a wide variety of crops using non-chemical means of pest and disease control. Closed ecological systems have different temporal biogeochemical cycling and ranges of atmospheric components because of their smaller reservoirs of air, water and soil, and higher concentration of biomass, and Biosphere 2 provided detailed examination and modeling of these accelerated cycles over a period of closure which measured in years. Medical research inside Biosphere 2 included the effects on humans of lowered oxygen: the discovery that human productivity can be maintained with good health with lowered atmospheric oxygen levels could lead to major economies on the design of space stations and planetary/lunar settlements. The improved health resulting from the calorie-restricted but nutrient dense Biosphere 2 diet was the first such scientifically controlled experiment with humans. The success of Biosphere 2 in creating a diversity of terrestrial and marine environments, from rainforest to coral reef, allowed detailed studies with comprehensive measurements such that the dynamics of these complex biomic systems are now better understood. The coral reef ecosystem, the largest artificial reef ever built, catalyzed methods of study now being applied to planetary coral reef systems. Restoration ecology advanced through the creation and study of the dynamics of adaptation and self-organization of the biomes in Biosphere 2. The international interest that Biosphere 2 generated has given new impetus to the public recognition of the sciences of biospheres (biospherics), biomes and closed ecological life systems. The facility, although no longer a materially-closed ecological system, is being used as an educational facility by Columbia University as an introduction to the study of the biosphere and complex system ecology and for carbon dioxide impacts utilizing the complex ecosystems created in Biosphere '.The many lessons learned from Biosphere 2 are being used by its key team of creators in their design and operation of a laboratory-sized closed ecological system, the Laboratory Biosphere, in operation as of March 2002, and for the design of a Mars on Earth(TM) prototype life support system for manned missions to Mars and Mars surface habitats. Biosphere 2 is an important foundation for future advances in biospherics and closed ecological system research.     

New instrumentation for optical measuring of oxygen in gas or dissolved in liquids.

The optical oxygen sensor is a novel device for the determination of oxygen in gases or dissolved in liquids. It is based on the measurement principle of fluorescence quenching, which is completely different from that of polarographic oxygen sensors (today the most widespread devices of oxygen detection). The new instrument offers features and advantages, which render it not only a realistic alternative, but, for specific applications, make it superior to existing electrochemical methods. The system is based on low-cost semiconductor devices (light-emitting diodes, photodiodes, low-cost analogue and digital components) and new LED-compatible oxygen-sensitive membranes. The flow cell of the instrument may be thermostatted and the sensor can be calibrated by a simple two-point calibration procedure. The optical oxygen sensor is particularly suitable for measuring dissolved oxygen in respirometry, since no oxygen is consumed by the device and the signal is independent of sample flowrate or stirring speed. Typical fields of application are monitoring of oxygen in ground and drinking water, in process control in bioreactors and in breath gas and blood gas analysis.     

带马尔可夫参数容错控制系统的可靠性分析

带马尔可夫参数的容错控制系统(FTCSMP,Fault Tolerant Control System with Markovian Parameters)作为一种描述主动容错控制系统(AFTCS,Active Fault Tolerant Control System)的模型,在一些文献中被用于系统稳定性分析.然而很少有文章研究FTCSMP的可靠性问题.以故障检测与隔离(FDI,Fault Detection and Isolation)装置监视下的冗余传感器组为研究对象,建立了其FTCSMP模型,进而研究该传感器/FDI装置的可靠性.在该模型中,用2个定义在不同状态空间中的齐次马尔可夫随机过程分别表示系统元件的故障过程和FDI装置的决策过程.基于马尔可夫理论,研究了传感器/FDI装置的可靠性和安全性.当FTCSMP中的系统故障过程和FDI过程为生灭过程时,将故障检测延迟时间分为"有效"和"无效"2种类型,分析了这2种延时对传感器/FDI装置可靠性、安全性的影响.以双余度惯导系统为例,给出了仿真例子.      

微处理器中含噪热传感器位置分布优化方法

高性能处理器普遍集成热传感器,采用动态热管理技术对芯片实施连续热监控。然而,由于实际芯片中的模拟或者数字热传感器不可避免伴随噪声,使动态热管理的可靠性受到很大影响。因此,为了提高热监控的精确性,本文运用主成分分析（PCA）技术对原始热图像样本矩阵进行降维近似处理,并结合矩阵扰动分析提出基于模拟退火算法的热传感器位置分布优化方法。实验结果表明：该方法比现有的贪婪算法在热重构误差、信噪比（SNR）和误警率等性能方面有了一定提高,能够有效运用在动态热管理中实现精确的热监控。     

热电偶温度传感器响应时间测试及分析

在国防及航天领域,研究热电偶温度传感器的动态响应特性,对动态过程的测量准确度和控制系统的实时性具有十分重要的工程价值和现实意义。使用热电偶温度传感器响应时间测试系统,对7只不同结构的热电偶温度传感器进行试验,根据对比分析时间常数及响应时间的测试结果,为动态温度信号测量过程中热电偶温度传感器的选型及使用提供参考。     

结构健康监测技术在航天运载器结构中的应用探索

为了探索结构健康监测技术在航天运载器结构中的应用,通过把微型传感器纳入箭体结构设计之中,和箭体结构集成为一体,从而达到结构自身对环境参数、受载情况的实时监测。以小型无线温度传感器为研究对象,通过方案设计和试验验证进行了初步探索,并针对在航天运载器结构中应用的后续工作提出思考。     

Life support for aquatic species--past; present; future.

Life Support is a basic issue since manned space flight began. Not only to support astronauts and cosmonauts with the essential things to live, however, also animals which were carried for research to space etc. together with men need support systems to survive under space conditions. Most of the animals transported to space participate at the life support system of the spacecraft. However, aquatic species live in water as environment and thus need special developments. Research with aquatic animals has a long tradition in manned space flight resulting in numerous life support systems for them starting with simple plastic bags up to complex support hardware. Most of the recent developments have to be identified as part of a technological oriented system and can be described as small technospheres. As the importance arose to study our Earth as the extraordinary Biosphere we live in, the modeling of small ecosystems began as part of ecophysiological research. In parallel the investigations of Bioregenerative Life Support Systems were launched and identified as necessity for long-term space missions or traveling to Moon and Mars and beyond. This paper focus on previous developments of Life Support Systems for aquatic animals and will show future potential developments towards Bioregenerative Life Support which additionally strongly benefits to our Earth's basic understanding.     

基于SiP技术的单片集成数字式太阳敏感器

设计了一种新型的数字式太阳敏感器。采用SiP（Stystem in Package）设计,将滤光片直接安装于探测器上。此设计减小了数字式太阳敏感器的体积与质量,可提高其可靠性。所设计的数字式太阳敏感器可用于深空探测卫星系统的太阳捕获和太阳定向,同时,也可作为星上其他光电敏感器的监护仪器,防止其他光学敏感器被强光损坏。最后,完成了原理样机的研制与标定,并在外场进行了太阳光斑的拍图测试。实验表明所提出方法可行,可满足火星探测、深空探测的使用需求。     

A root moisture sensor for plants in microgravity.

Development of components for bioregenerative life-support systems is a vital step toward long-term space exploration. The culturing of plants in a microgravity environment may be optimized by the use of appropriate sensors and controllers. This paper describes a sensor developed for determining the amount of fluid (nutrient solution) available on the surface of a porous ceramic nutrient delivery substrate to the roots of conventional crop plants. The sensor is based on the change in thermal capacitance and thermal conductance near the surface as the moisture content changes. The sensor could be employed as a data acquisition and control sensor to support the automated monitoring of plants grown in a microgravity environment.     

电学前沿计量技术在航天型号保障中的应用

针对航天器中电学基准的长期稳定性、多种传感器输出电信号的线性度、电脉冲测量的时延等多个航天电测领域的难题,提出采用电学量子计量技术和计算基准技术的解决方案,可以10^-9量级的不确定度测量航天器中电阻基准短期变化量,从而推算出长期变化量,对航天器的稳定控制具有重要作用;可以极小的不确定度校准多种传感器输出的毫伏、微伏量级电压的线性度,对航天传感器测量准确度具有重要意义;可在10^-9秒量级确定电脉冲测量中电阻引入的时延,对航天器电推进系统的控制具有重要作用。     

基于多传感器的卫星自主导航信息融合算法

通常卫星上装有较多的自主导航传感器,如何将其信息有效的组织并充分利用,是卫星自主导航的关键问题。采用信息融合技术把两种或多种导航系统组合起来,应用最优估计理论,形成最优组合导航系统,有利于充分运用各导航系统的信息进行信息互补和信息合作,已逐渐成为了导航定位技术的发展方向。文章针对星敏感器、红外地平仪、雷达高度计、紫外敏感器组成的卫星自主导航系统的特点,提出了一种基于联邦卡尔曼滤波技术进行轨道确定的信息融合算法。仿真结果表明,该方案能够获得较高的定轨精度,有效抑制滤波发散,整个系统的运算速度和收敛速度也有所提高。     

Evaluation and modification of commercial infra-red transducers for leaf temperature measurement.

Accurate measurement of the leaf to air temperature gradient is crucial for the determination of stomatal conductance and other plant responses in both single leaves and in plant canopies. This gradient is often less than 1 degree C, which means that leaf temperature must be known to within about +/- 0.1 degree C. This is a challenging task, but new, miniature infra-red transducers from Exergen Corporation (Newton, MA) and Everest Interscience (Tucson, AZ) can be modified and calibrated to achieve this accuracy. The sensors must be modified to add thermal mass and the Exergen sensor requires a measurement of sensor body temperature. Significant error is caused by the discharge of a capacitor in the standard Exergen sensor, but we tested it without the capacitor. The sensors respond rapidly to changes in target temperature, but require 2 to 10 minutes to respond to changes in sensor body temperature, which is often the largest source of error. A new, sensitive method for measuring field of view indicates substantial peripheral vision for both sensors and a wider field of view than specified by the manufacturers. Here we describe sensor output as a function of target and sensor body temperatures, and provide a generic (sensor independent) equation that can be used to achieve +/- 0.2 C accuracy with Exergen sensors. The equation was developed and verified using two black body calibrators.     

电学前沿计量技术在航天型号保障中的应用

针对航天器中电学基准的长期稳定性、多种传感器输出电信号的线性度、电脉冲测量的时延等多个航天电测领域的难题,提出采用电学量子计量技术和计算基准技术的解决方案,可以10^-9量级的不确定度测量航天器中电阻基准短期变化量,从而推算出长期变化量,对航天器的稳定控制具有重要作用;可以极小的不确定度校准多种传感器输出的毫伏、微伏量级电压的线性度,对航天传感器测量准确度具有重要意义;可在10^-9秒量级确定电脉冲测量中电阻引入的时延,对航天器电推进系统的控制具有重要作用。     

机器人多维力传感器的研究进展

机器人多维力传感器是机器人与人和外界环境交互的重要部件。力感知技术作为机器人的四大关键技术之一,在抓取、打磨、装配以及健康医疗等领域得到了广泛应用。本文针对机器人多维力传感器当前的研究进展情况进行了概述。首先对几种常用的多维力传感器的研究现状进行了简单地介绍。然后介绍了几种典型的弹性体结构和改进的弹性体结构。此外,对多维力传感器的标定方法进行了总结,并对标定中存在的问题进行了讨论。由于维间耦合是影响传感器精度的关键因素,且广泛存在于各种结构的多维力传感器中,所以减小或消除维间耦合成为多维力传感器研究中的一个不可或缺的内容,因此本文对多维力传感器的解耦方法进行了综述。在动态力信号测量场合,需要动态性能好的多维力传感器,因此本文还给出了多维力传感器动态性能补偿的一般方法,并分析了运动中的机器人多维力传感器存在的惯性力问题及一般的解决方法。最后,本文对多维力传感器技术的未来发展趋势提出了新思路,并指出了未来需要解决的问题。     

基于联合滤波器的高精度卫星定姿系统设计

设计了由陀螺、GPS姿态敏感器、红外地平仪和太阳敏感器构成的太阳同步极轨卫星姿态确定系统。提出联邦滤波器结构和算法,推导了各子系统的量测方程和姿态确定系统的误差状态方程。为规避对量测值进行非相关处理,采用减小GPS姿态敏感器输出的姿态滤波值作为系统滤波器量测值的频率的方法。仿真结果表明,采用联邦滤波器对多敏感器卫星姿态确定系统进行信息融合,具有计算量小、精度高、可靠性好等优点。     

对一类传感器故障具有完整性的鲁棒容错控制

针对线性系统的不确定性,考虑一类传感器可能出现的故障,即传感器信号增益减小、信号时有时无以及信号通道完全断开的故障情况,利用最优二次型(LQR)理论设计系统的鲁棒容错控制器,既可以保证闭环系统的鲁棒性,又可以保证闭环系统的完整性.给出了结论和证明,设计得到的控制器在传感器正常时以及传感器出现该类故障时都可以保证闭环系统的稳定性.仿真结果表明了方法的有效性.     

Quantitative criteria for estimation of natural and artificial ecosystems functioning.

Using biotic turnover of substances in trophic chains, natural and artificial ecosystems are similar in functioning, but different in structure. It is necessary to have quantitative criteria to evaluate the efficiency of artificial ecosystems (AES). These criteria are dependent on the specific objectives for which the AES are designed. For example, if AES is considered for use in space, important criteria are efficiency in use of mass, power, volume (size) and human labor and reliability. Another task involves the determination of quantitative criteria for the functioning of natural ecosystems. To solve the problem, it is fruitful to use a hierarchical approach suitable for both individual links and the ecosystem as a whole. Energy flux criteria (principles) were developed to estimate the functional activities of biosystems at the population, community and ecosystem levels. A major feature of ecosystems as a whole is their biotic turnover of matter the rate of which is restricted by the lack of limiting substances. Obviously, the most generalized criterion is to take into account the energy flux used by the biosystem and the quantity of limiting substance included in its turnover. The use of energy flux by ecosystem, E(USED)--is determined from the photoassimilation of CO2 by plants (per time unit). It can be approximately estimated as the net primary production of photosynthesis (NPP). So, the ratio of CO2 photoassimilation rate (sometimes, measured as NPP) to the total mass of limiting substrate can serve as a main universal criterion (MUC). This MUC characterizes the specific cycling rate of limiting chemical elements in the system and effectiveness of every ecosystem including the global Biosphere. Comparative analysis and elaboration of quantitative criteria for estimation of natural and artificial ecosystems activities is of high importance both for theoretical considerations and for real applications.     

Transformation of a delta: Converting estuaries to lakes

In this century large-scale transformations have been carried out in the delta of the Rhine, Meuse and Scheldt in The Netherlands. The following principal consequences are considered: the loss of estuarine ecosystems, the change in the process of sedimentation and erosion, and the development of new aquatic and terrestrial ecosystems. The ecological consequences of the transformation of the Grevelingen estuary into a salt-water lake and some surprising developments are described briefly. The need for a limited restoration of the water exchange between the lake and the North Sea is indicated, as well as the major impacts of the exchange. The necessity for the maintenance or restoration of estuaries, the ecological development and the possibilities of the new lakes, and the management of these lakes by engineering structures are discussed. Careful land-use planning and ecosystem management, backed by research, are needed to make the fullest possible use of the potential offered by new lakes. It is also concluded that salt lakes have interesting perspectives.