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为了提高磁引信中三分量磁探头灵敏度的检测效率,设计了探头灵敏度批量检测装置。该装置利用三个两两正交的磁场线圈,通过电脑程控的方式依次施加恒定的磁场,并自动采集磁传感器的输出然后计算探头的灵敏度。与原有的检测装置相比较,本文提出的方法大大提高了检测效率——可节约2/3的检测时间,并且减少了人工频繁装夹磁探头的作业强度。 相似文献
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<正> 笔者曾在本刊1996年第12期上发表的“新型微功耗磁传感探测器”一文中,介绍了该探测器的基本原理、电路构成和应用前景。本文作为上述文章的补充,较详细地阐述新型微功耗磁传感探测器所用的关键部件——新型微功耗磁传感器在不同应用场合要考虑和解决的实际技术问题。 现已能提供用户选用的新型微功耗磁传感器有φ43×19毫米和φ36×19毫米两种规格。传感器有一根三芯电缆相连,其中一根芯线和屏蔽线作为电源输入线,其余两根芯线为传感器的信号输出线。传感器由6伏稳压电源供电,红色芯线接电源正极,屏蔽层编织线接电源负极。两根信号输出端线可组成平衡方式输出,也可以接成非平衡方式输出。传感器只要接上电源,就能正常工作,用电压表或电平记录仪作为终端显示装置就能得到代表传感器所在地点存在的磁场 相似文献
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Integrated semiconductor magnetic field sensors 总被引:1,自引:0,他引:1
《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1986,74(8):1107-1132
A magnetic field sensor is an entrance transducer that converts a magnetic field into an electronic signal. Semiconductor magnetic field sensors exploit the galvanomagnetic effects due to the Lorentz force on charge carriers. Integrated semiconductor, notably silicon, magnetic field sensors, are manufactured using integrated circuit technologies. Integrated sensors are being increasingly developed for a variety of applications in view of the advantage offered by the integration of the magnetic field sensitive element together with support and signal processing circuitry on the same semiconductor chip. The ultimate goal is to develop a broad range of inexpensive batch-fabricated high-performance sensors interfaced with the rapidly proliferating microprocessor. This review aims at the recent progress in integrated silicon magnetic devices such as integrated Hall plates, magnetic field-effect transistors, vertical and lateral bipolar magnetotransistors, magnetodiodes, and current-domain magnetometers. The current development of integrated magnetic field sensors based on III-V semiconductors is described as well. Bulk Hall-effect devices are also reviewed and serve to define terms of performance reference. Magnetic device modeling and the incorporation of magnetic devices into an integrated circuit offering in situ amplification and compensation of offset and temperature effects are further topics of this paper. Silicon will continue to be aggressively exploited in a variety of magnetic (and other) sensor applications, complementary to its traditional role as integrated circuit material. 相似文献
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Bradshaw L.A. Ladipo J.K. Staton D.J. Wikswo J.P. Jr. Richards W.O. 《IEEE transactions on bio-medical engineering》1999,46(8):959-970
Electrical activity in the gastrointestinal system produces magnetic fields that may be measured with superconducting quantum interference device magnetometers. Although typical magnetometers have detection coils that measure a single component of the magnetic field, gastric and intestinal magnetic fields are vector quantities. We recorded gastric and intestinal magnetic fields from nine abdominal sections in nine normal human volunteers using a vector magnetometer that measures all three Cartesian components of the magnetic field vector. A vector projection technique was utilized to separate the magnetic field vectors corresponding to gastric and intestinal activity. The gastric magnetic field vector was oriented in a cephalad direction, consistent with previously observed data, and displayed oscillatory characteristics of gastric electrical activity (f = 3.03 +/- 0.18 cycles/min). Although the small bowel magnetic field vector showed no consistent orientation, the characteristic frequency gradient of the small bowel electrical activity was observed. Gastric and intestinal magnetic field vectors were oriented in different directions and were thus distinguished by the vector projection technique. The observed difference in direction of gastric and intestinal magnetic field vectors indicates that vector recordings dramatically increase the ability to separate physiological signal components from nonphysiological components and to distinguish between different physiological components. 相似文献
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Kawahito S. Maier C. Schneiher M. Zimmermann M. Baltes H. 《Solid-State Circuits, IEEE Journal of》1999,34(12):1843-1851
This paper presents a CMOS two-dimensional (2-D) vector magnetic sensor system integrating two planar microfluxgate sensors and the complete electronics for sensor excitation and signal readout. The system is based on an industrial 0.8-μm double-poly, double-metal CMOS technology with ferromagnetic NiFeMo cores added in a simple postprocessing sequence. The fluxgate sensors are embedded in a ΣΔ analog-to-digital converter for a stable and precise digital detection of weak magnetic fields. A cascaded ΣΔ modulator topology is utilized to obtain second-order noise shaping and to suppress pattern noise. Within the range of ±50 μT, the system nonlinearity is less than 1.5 μT. The angular resolution as a 2D vector sensor is less than 4° for a measured magnetic induction of 50 μT. This makes the 2-D microfluxgate magnetometer suitable for use as fully integrated electronic compass 相似文献
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In many monitoring applications such as smart home and surveillance, deployment of multiple depth sensors increases monitoring area and offers better occlusion handling which is not sensitive to illumination condition in comparison with RGB sensors. However, multiple sensors also increase the volume of data associated with signal processing alongside the associated computational complexity and power consumption. In order to address these drawbacks, this paper proposes a novel change detection algorithm that can be used as a part of a sensor scheduler in a centralized (e.g. star) network configuration. Initially, each sensor in the network performs a unique single scan of the common environment in order to detect any incremental changes in the sensed depth signal. This initial change detection is then used as a basis for several follow-up tasks such as foreground segmentation, background detection, target detection, and tracking for monitoring tasks. Here, instead of processing a complete depth frame, we proposed to utilize a collection of 1D scans of the depth frames. A confidence function is defined that can be used to estimate the reliability of the detected changes in each sensor and to reduce any false positive events which can be triggered by the noise and outliers. Analysis of the proposed confidence function is carried out through performance analysis in the presence of sensor noise and other parameters which can affect the reliability of the sensed data of each sensor. Finally, a score function is defined based on the confidence of the detected parameters and sensor resolution in order to rank and match sensors with the associated objects to be tracked. It results in tracking target(s) by a sensor (or sensors) that offer a high tracking score. This approach offers many advantages such as decreasing the overall system power consumption by placing the sensors with a low confidence value on standby mode and reducing the overall computational overheads. 相似文献
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Performance analysis of a color CMOS photogate image sensor 总被引:3,自引:0,他引:3
The performance of a color CMOS photogate image sensor is reported. It is shown that by using two levels of correlated-double sampling it is possible to effectively cancel all fixed-pattern noise due to read-out circuit mismatch. Instead the fixed-pattern noise performance of the sensor is limited by dark current nonuniformity at low signal levels, and conversion gain nonuniformity at high signal levels. It is further shown that the imaging performance of the sensor is comparable to low-end CCD sensors but inferior to that reported for high-end CCD sensors due to low quantum efficiency, high dark current, and pixel cross-talk. As such the performance of CMOS sensors is limited at the device level rather than at the architectural level. If the imaging performance issues can be addressed at the fabrication process level without increasing cost or degrading transistor performance, CMOS has the potential to seriously challenge CCD as the solid-state imaging technology of choice due to low power dissipation and compatibility with camera system integration 相似文献
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Yongliang Yang 《Microelectronic Engineering》2010,87(11):2317-2322
This paper presents a quad-cantilever microsensor for on-the-spot detection of ultra-low concentration chemical vapors. Compared with conventional dual-cantilever sensors, the quad-cantilever configuration can form a fully cantilever-formed Wheatstone-bridge that possesses a higher sensitivity of twofold and more balanced condition to compensate for environmental noise like temperature fluctuation or air flow. Besides, the four integrated micro-cantilevers are made of SiO2, with each having a single crystal silicon piezoresistor fully encapsulated by SiO2. Thus, the quad-lever sensor achieves a very low signal noise of 0.2 μV. For specific detection, sensitive molecule layer is self-assembled on two sensing cantilevers, with another two as reference. The sensors are micro-fabricated with a single-side process from the wafer front-side. With wet anisotropic etch used to release the piezoresistive cantilevers, the new fabrication technique features low-cost and high-yield. Self-assembled with a novel dual-branch specific mono-layer, about 100 ppt level trinitrotoluene (TNT) vapor has been rapidly and repeatedly detected. 相似文献