The report documents the characterization of the impulse response of piezoelectric thin-film transducers to low-impacts provided by a 'ball-drop' apparatus and the effects of device size and annealing process on the impulse response. The specific piezoelectric thin-film transducers are 1-micron thick Lead Zirconate Titanate (PZT) films, as deposited by Army Research Laboratory's (ARL's) Sensors and Electronics Devices Directorate in support of Army Technology Objective Sensor, Warhead, and Fuzing Technology Integrated for Combined Effects (SWFTICE) during Fiscal Year (FY) 2011. Summary results are of low-yield for these specific lot fabrications, but iterative designs/fabrications are forthcoming from laboratory fabrication for further testing.

关键词：冲击传感器；铅锆钛酸盐；铁电材料；薄膜；转换器

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The problem of simultaneously accommodating unknown sensor biases and unknown actuator failures in uncertain systems is considered in a direct model reference adaptive control (MRAC) setting for state tracking using state feedback. Sensor biases and actuator faults may be present at the outset or may occur at unknown instants of time during operation. A modified MRAC law is proposed, which combines sensor bias estimation with control gain adaptation for accommodation of sensor biases and actuator failures. This control law is shown to provide signal boundedness in the resulting system. For the case when an external asymptotically stable sensor bias estimator is available, an MRAC law is developed to accomplish asymptotic state tracking and signal boundedness. For a special case wherein biases are only present in the rate measurements and bias-free position measurements are available, an MRAC law is developed using a model-independent bias estimator, and is shown to provide asymptotic state tracking with signal boundedness.

关键词：执行器；自适应控制；自适应控制；不确定系统

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Inspired by the roles of hair cells in nature, this study aims to develop and characterize two new sets of novel flow sensors. One set of sensors developed and studied in this work are flow sensors fabricated using carbon nanomaterials. These sensors are made by embedding carbon nanotubes (CNT) and carbon nanohorns (CNH) into a polymeric substrate and then tested by flowing a conductive aqueous solution over the surface of the exposed CNT and CNH. In response, a flow-dependent voltage is generated. The surface coverage and the electrical relationship between the sensor and water is investigated and the voltage measurements of sensors with different levels of resistance were tested in varying fluid velocities. In response to these fluid velocities, the least resistive sensor showed small, but detectable changes in voltages, while higher resistance sensors showed less response. In addition, plasma treatment of the carbon nanomaterial/PDMS films were conducted in order to render the PDMS on the surface hydrophilic and in turn to pull more fluid towards the carbon material. This showed to improve the sensitivity of the flow sensors. This work also builds on previous research by investigating the flow dependent electrical response of a 'skin'-encapsulated artificial hair cell in an aqueous flow. An artificial cell membrane is housed in a flexible polyurethane substrate and serves as the transduction element for the artificial hair cell. Flow experiments are conducted by placing the bio-inspired sensor in a flow chamber and subjecting it to pulse-like flows. This study demonstrates that the encapsulated artificial hair cell flow sensor is capable of sensing changes in flow through a mechanoelectrical response and that its sensing capabilities may be altered by varying its surface morphology.

关键词：传感器；碳纳米管；探测器；流量；生物工程

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Wireless sensor detection is readily accessible, easily deployable, and usable technology that provides public-safety personnel with an early-warning and identification tool in the event of a Chemical Biological Radiological Nuclear (CBRN) incident. This is accomplished by incorporating wireless sensor detection capability into the Los Angeles Fire Department's (LAFD) hazardous-materials operations. Due to the relative ease of use and low cost of deployment, it makes sense that the LAFD employ wireless technology, capitalizing on the advantages. The question regarding CBRN wireless sensor network capability is whether this technology is suitable, reliable, user friendly, and quickly deployable. Furthermore, will this technology provide critical early warning, detection, and subsequent notification in real time. The goal of this thesis is to determine CBRN wireless sensor detection capability in terms of reliability, deployment, early warning, and notification. The objective is to outline a concept of operations document providing the need structure for incorporating wireless sensor detection capability into public-safety operations. Through field deployments and exercises using sensor detectors, standardized equipment, and software, the LAFD will have better access to early detection and notification of CBRN material releases. The end result means a more efficient, cost-effective tool that readily detects hazardous products, providing an early warning capability.

关键词：无线传感器；生物战剂探测器；化学剂探测器；无线链路

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In-situ reduction of graphite oxide in polymer powder has been implemented using focused solar electromagnetic radiation. Graphene has proved that it can act as alternative filler in nanocomposites due to its high electronic transport properties and its use in advanced polymer composites for EMI shielding applications. With an applied load, strain measured and corresponding change in resistance of the reduced graphite oxide-polymer composites has been observed. The morphological, structural, electrical, thermal, and electromechanical characteristics of the reduced graphene-PVDF were studied. A gauge factor was obtained demonstrating a promising application as a strain sensor in structural health monitoring.

关键词：传感器；电磁辐射；石墨；聚合物；碳纳米管；复合材料

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An inter-calibration method is developed to provide absolute radiometric calibration of narrow-swath imaging sensors with reference to non-coincident wide-swath sensors. The method predicts at-sensor radiance using non-coincident imagery from the reference sensor and knowledge of spectral reflectance of the test site. The imagery of the reference sensor is restricted to acquisitions that provide similar view and solar illumination geometry to reduce uncertainties due to directional reflectance effects. Spectral reflectance of the test site is found with a simple iterative radiative transfer method using radiance values of a well-understood wide-swath sensor and spectral shape information based on historical ground-based measurements. At-sensor radiance is calculated for the narrow-swath sensor using this spectral reflectance and atmospheric parameters that are also based on historical in situ measurements. Results of the inter-calibration method show agreement on the 2 5 percent level in most spectral regions with the vicarious calibration technique relying on coincident ground-based measurements referred to as the reflectance-based approach. While the variability of the inter-calibration method based on non-coincident image pairs is significantly larger, results are consistent with techniques relying on in situ measurements. The method is also insensitive to spectral differences between the sensors by transferring to surface spectral reflectance prior to prediction of at-sensor radiance. The utility of this inter-calibration method is made clear by its flexibility to utilize image pairings with acquisition dates differing in excess of 30 days allowing frequent absolute calibration comparisons between wide- and narrow-swath sensors.

关键词：传感器；光谱带；灵敏度；成像技术；辐射传输

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We present a queueing-theoretic framework to evaluate the performance of large-scale, querybased wireless sensor networks whose nodes detect and advertise significant events that are useful for only a limited time; queries generated by the nodes of the network are also time-limited. The main performance parameter is the steady state proportion of generated queries that fail to be answered on time. Using an infinite transmission range model, we first provide an approximation for this parameter that is insensitive to the size of the network. Subsequently, we approximate the proportion of failed queries when the transmission range is limited and show that this proportion converges to its infinite range counterpart as the sensor transmission range tends to infinity. The analytical approximations are shown to be remarkably accurate when compared with benchmark values obtained using a commercial network simulator.

关键词：通信网络；探测器；排队理论；无线传感器

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In 2007, the Federal Aviation Administration (FAA) Airport Technology Branch conducted a performance assessment of the FODetect(Trade Name), a hybrid radar and electro-optical foreign object debris (FOD) detection system developed by Xsight Systems, Ltd. This assessment included the systems capability to detect objects of various shapes, sizes, and materials at all locations on the runway surface. The systems capability to detect FOD during both nighttime and daytime conditions, in periods of sun, rain, mist, fog, and snow, was also assessed. The FODetect system was initially demonstrated in January 2008. Following the demonstration, a more comprehensive performance assessment of the technology was conducted at the Boston Logan International Airport. The performance assessment was initiated in June 2008 with a test schedule that continued until May 2009. Researchers conducted several test sessions to assess the FODetects capability to detect selected FOD items. The tests focused on hybrid sensor characteristics, specifically the joint capabilities of radar and electro-optical sensors operating together. The FODetect system was able to detect the objects of various shapes, sizes, and materials on runway surfaces and perform satisfactorily in nighttime, daytime, sun, rain, mist, fog, and snow conditions, as required by FAA Advisory Circular 150/5220-24, 'Airport Foreign Object Debris (FOD) Detection Equipment.'

关键词：雷达；探测；光电子技术；航空安全；FOD系统

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This report describes data collected during one of a series of NRL remote sensing and calibration and validation (Cal/Val) campaigns, undertaken to develop models of coastal environments for use in rapidly processing hyperspectral imagery (HSI) and generating shallow water bathymetric charts and trafficability maps. This report describes data collected during the Hawaii- Hyperspectral Airborne Remote Environmental Sensing (HIHARES'09) experiment conducted at Marine Corps Base Hawaii and Marine Corps Training Area-Bellows from January 21 to February 6, 2009. Airborne HSI from the HyMap(TM) sensor was collected over these sites and adjacent areas in conjunction with NRL Cal/Val activities that sampled spectral and geotechnical data for the development and validation of trafficability, shallow water bathymetry, and vegetation maps appropriate to this coralline coast type. Trafficability maps and shallow water bathymetry maps were derived for HIHARES'09 study sites preparatory to an experiment at Shoalwater Bay, Australia, to support the development of imagery- derived trafficability maps for exercise TALISMAN SABER '09.

关键词：远程探测器；高光谱图像；测深，校准

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关键词：传感器；碳化硅；高超声速飞行器；数学模型；微机电系统

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