基于有向感知模型的传感器网络密度控制算法

密度控制是一种常用的延长大规模传感器网络工作寿命的方法,现有的密度控制算法大多基于全向感知模型,而满足有向感知模型的传感器网络也颇具实际应用价值.文中提出一种基于有向感知模型的传感器网络密度控制算法,在保证一定网络覆盖能力的前提下,有效地休眠冗余有向感知节点,降低网络总能耗,延长网络工作寿命.     

Linear Wireless Sensor Networks Energy Minimization Using Optimal Placement Strategies of Nodes

Wireless Personal Communications - Nowadays, the recent developments in the field of wireless sensor networks (WSNs) have initiated new applications of WSNs which can be used in many fields, such...     

扩大感光动态范围的象限光电传感器的研究

介绍了一种可调整感光动态范围的象限传感器的设计。该传感器采用 0 .6微米 CMOS标准工艺制造 ,包含有 1 6× 1 6有源光电管阵列 ,相关二次采样 (CDS)电路 ,输出缓冲放大电路和数字控制电路几个主要功能模块 ,实现了象限传感器与 CMOS处理电路的兼容集成。该传感器对目标单帧传感的感光动态范围为 60 d B,通过变频二次扫描进行感光动态范围的调整后 ,传感器总的感光动态范围可以提高为 84d B。     

一种宽电压范围的DCR电流采样电路

基于0.35μm BCD工艺,设计了一款面向宽输出电压范围Buck变换器的DCR电流采样电路。内含电平位移电路与浮动电压产生电路,可以在宽电压范围内正常工作,满足启动、短路保护、高占空比等多种工作条件下的电流采样。仿真结果显示,所提出的DCR电流采样电路应用于输出电压为2.5～24V、开关频率为100k Hz～1MHz的Buck变换器中时,DCR电流采样电路的增益为15.4d B,-3 d B带宽为9.35 MHz,输入电压范围为0～24 V,实现了精准稳定的电感电流采样功能。     

低功耗高动态范围CMOS图像传感器的设计

设计了一种低功耗高动态范围的CMOS图像传感器16×16像素阵列电路,采用条件重置的方法,钟控比较器的低功耗设计及相关时序电路的优化,在扩展CMOS图像传感器的动态范围下,极大地降低了系统的功耗.实验表明,基于标准CSM 0.35μm 2P4M CMOS工艺,用HSPICE仿真,动态范围最大可以达到普通传感器的4倍,在3.3 V下每列功耗仅为6.6μW.     

基于插值法的浮标优化布放

针对声纳浮标搜索扩散运动目标浮标阵参数优化问题,提出基于插值法的声纳浮标优化布放。建立了目标航向不变和目标航向改变条件下,声纳浮标搜索概率计算解析模型。基于插值算法得到声纳浮标布阵参数和搜索概率的关系曲线,进而获得声纳浮标最佳布阵参数。仿真结果表明,基于插值法的声纳浮标优化布放方法可获得最佳布阵参数使得搜索概率最高。     

Efficient Sensing Topology Management for Spatial Monitoring with Sensor Networks

We focus on exploiting redundancy for sensor networks in the context of spatial interpolation. The network acts as a distributed sampling system, where sensors periodically sample a physical phenomenon of interest, e.g. temperature. Samples are then used to construct a continuous spatial estimate of the phenomenon over time through interpolation. In this regime, the notion of sensing range typically utilized to characterize redundancy in event detection applications is meaningless and sensor selection schemes based on it become unsuitable. Instead, this paper presents pragmatic approaches for exploiting redundancy in such applications. Their underlying characteristic is that no a-priori assumptions need to be made on the statistical properties of the physical phenomenon. These are instead learned by the network after deployment. Our approaches are evaluated through real as well as synthetic sensor network data showing that significant reductions in the number of active sensors are indeed possible.     

Efficient Placement and Dispatch of Sensors in a Wireless Sensor Network

Sensor deployment is a critical issue because it affects the cost and detection capability of a wireless sensor network. In this work, we consider two related deployment problems: sensor placement and sensor dispatch. The former asks how to place the least number of sensors in a field to achieve sensing coverage and network connectivity, and the latter asks how to determine from a set of mobile sensors a subset of sensors to be moved to an area of interest with certain objective functions such that the coverage and connectivity properties are satisfied. This work is targeted toward planned deployment. Our solution to the placement problem allows an arbitrary-shaped sensing field possibly with arbitrary-shaped obstacles and an arbitrary relationship between the communication distance and sensing distance of sensors and, thus, significantly relaxes the limitations of existing results. Our solutions to the dispatch problem include a centralized one and a distributed one. The centralized one is based on adopting the former placement results and converting the problem to the maximum-weight maximum-matching problem with the objective of minimizing the total energy consumption to move sensors or maximizing the average remaining energy of sensors after movement. Designed in a similar way, the distributed one allows sensors to determine their moving directions in an autonomous manner.     

低量程高精度压力传感器芯片设计与工艺

介绍了通过半导体单岛膜结构设计和MEMS工艺技术对扩散硅原理的压力传感器设计及应用进行了拓展.在低量程范围较大幅度提搞了压力传感器精度,并对实现产品关键工艺条件进行了描述.     

Novel Logarithmic Active Pixel Sensor with High Dynamic Range and High Output Swing

The logarithmic response complementary metal oxide semiconductor （CMOS） image sensor provides a wide dynamic range, but its drawback is the lack of simple fixed pattern noise（FPN） cancellation scheme. Designed is a novel logarithmic active pixel sensor（APS） with high dynamic range and high output swing. Firstly, the operation principle of mixed-model APS is introduced. The pixel can work in three operation modes by choosing the proper control signals. Then, FPN sources of logarithmic APS are analyzed, and double-sampled technique is implemented to reduce FPN. Finally, according to the simulation results, layout is designed and has passed design rule check（DRC）, electronic rule eheck（ERC） and layout versus schematic（LVS） verifications, and the post-simulation results are basically in agreement with the simulation results. Dynamic range of the new logarithmic APS can reach about 140 dB; and the output swing is about 750 inV. Results show that by using double sampled technique, most FPN is eliminated and the dynamic range is enhanced.     

梳状谐振式磁场传感器设计

给出了一种新型梳状微机械谐振式磁场传感器的设计。采用静电激励和静电检测,通过罗伦兹力的反馈将磁场的大小转变为频率输出。对结构模型进行简化,推导出了本征频率的计算公式并进行了ANSYS模拟。通过尺寸的设计,该传感器的灵敏度可以达到258kHz/T。     

梳状谐振式磁场传感器设计

给出了一种新型梳状微机械谐振式磁场传感器的设计。采用静电激励和静电检测，通过罗伦兹力的反馈将磁场的大小转变为频率输出。对结构模型进行简化，推导出了本征频率的计算公式并进行了ANSYS模拟。通过尺寸的设计，该传感器的灵敏度可以达到258kHz/T。     

从用户角度看芯片贴装头技术

现代制造商一直特别看重在变动过程中迅速重新配置平台型贴装机的灵活性,以便能够对变动后的产品实现最优的贴装能力.现在,平台型贴装设备上提供的新一代贴装头技术扩展了这些系统的能力,可以提供高速芯片贴装功能,实现能够在不需重新配置,不会影响精度、良品率或产能的情况下,贴装常用的各种元件.它能使未来几代装配商将从更加灵活、自适应和精确的贴装头中受益,他们将提高利用率,大大降低变动时间,明显减少支持高速度、低成本、快速交货周期制造环境所需的反应时间.     

基于光纤偏振特性的压力传感中测量范围的拓展方法

测量范围的拓展对提升基于偏振特性的光纤压力传感系统的实用性有着重要意义.以拓宽测量范围并保持原有传感灵敏度为目标,提出了一种基于斯托克斯多参量融合的传感方案.通过理论仿真得到传感头目标偏振轴.利用偏振控制器,压力装置和偏振检测计,在实验中得到了线性度为99.8％、灵敏度为0.1938 N-1、测量范围为28 N的传感性...     

红外传感技术面面观

利用红外应答器识别和传输物体信息是一种新的技术尝试,与RFID技术相比,这项技术具有许多优点,特别是应用于物联网终端时,更有更大的优势。     

Optimal Placement of Wireless Nodes for Maximizing Path Lifetime

In this work we investigate the deployment of wireless nodes in order to maximize the lifetime of a data flow. We develop a mathematical model for determining the best placement of nodes by taking into consideration the energy of each node involved in the data flow. By using our mathematical model we achieve two major objectives: the maximization of the shortest node's lifetime and the convergence of all the nodes' lifetime to a unique value.     

Appropriate Sensor Placement for Fault-Tolerant Lane-Keeping Control of Automated Vehicles

This paper deals with the sensor placement problem in the realization of failure-tolerant lane-keeping control of front-wheel-steered automated vehicles. The scenario considered is one in which lane-keeping action is performed using two sensors that independently measure the lateral deviation of their locations of installation from a reference. The problem of interest is to determine appropriate locations for their installation so that the vehicle can be steered safely even in the event of failure of one of the two sensors. It is shown that for safe lane-keeping action at low as well as high speeds, both sensors should be placed ahead of the rear axle of the vehicle. In addition, the paper discusses a pedagogical problem - namely, the lane-keeping control problem with lateral error information from a sensor placed behind the rear axle. It is shown that, contrary to intuition, it is easier to steer the vehicle at higher speeds. Results based on experiments conducted on vehicles used in the Partners for Advanced Transit on Highways (PATH) program demonstrate the validity of analytical predictions.     

Development of a Wireless Sensor Network with Optical Electric Sensor for Electric Field Measurement

The area of high voltage direct current (HVDC) transmission line is very large, so using cable for electric field monitoring system is very inconvenient. Wireless sensor network (WSN) can solve this problem. Compared with the traditional communication network, WSN has the advantages of small volume, high flexibility, strong self-organization. So it’s more suitable for the construction of distributed electric field monitoring system which has long distance and high mobility. On the other hand, optical E-field sensors are passive devices and they have such advantages as compact structure, wide-band response and wide measuring range which mechanical sensors lack. A distributed wireless system with optical E-field sensor is designed for collecting and monitoring the electric field under HVDC transmission lines. This measurement system has been used in China’s state grid HVDC test base and power transmission projects. Based on the experimental results, this measurement system demonstrates that it can adapt to the complex electromagnetic environment under the transmission lines and can accomplish the accurate, flexible, and stable demands of the electric field measurement.

     

The Sink Node Placement and Performance Implication in Mobile Sensor Networks

Mobile sensor networks are desirable in a variety of application scenarios, in which information collection is no doubt of great importance. In this paper, we present a mobile sensor network architecture consisting of a potentially large number of mobile sensors and a single or multiple stationary sink nodes for sensing information collection. We formulate a distinct coverage measurement problem in term of sensing information collection; we study the relevant performance and examine the effect from a variety of relevant factors through extensive simulations. We demonstrate that the performance is not only affected by the sensor mobility and the transmission range between mobile sensors and sink node(s), but also by the distribution of mobile sensors and the number and locations of sink nodes. Based on the observation and analysis, we also provide some preliminary understandings and implications for improving the information collection performance.