共查询到19条相似文献,搜索用时 203 毫秒
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谐振式传感器由于其重量轻、精度高、响应快在压力测量领域获得了飞速发展,传感器的构成包括机械谐振子在内的机电一体的谐振系统,而驱动系统对保持机械谐振器振荡的稳定性和可靠性起着重要作用.本文针对一种典型结构的谐振式压力传感器,分析比较了不同的闭环驱动结构,最后构建了其行为级闭环自激仿真模型,在MATLAB中对自激回路的起振情况进行了仿真;验证了AGC对压力传感器幅度与频率的双重跟踪性. 相似文献
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谐振式压力传感器利用正反馈原理,构成包括机械谐振子在内的机电一体的高品质闭环谐振系统,闭环拓扑结构对保持机械谐振器振荡的稳定性和可靠性起着重要作用。本文针对一种典型结构的静电驱动电容检测谐振式压力传感器,在分析工作原理的基础上,构建了其行为级闭环自激仿真模型,在MATLAB中对自激回路的起振情况进行了仿真;最后设计了基于AGC的闭环控制电路。 相似文献
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在对圆筒谐振子的数学模型计算和有限元分析的基础上,设计了一种新型的谐振式液体密度传感器.该传感器由双端固定的圆筒谐振子、自动增益和相位调节的测量控制电路、C8051F020单片机的信号处理系统组成,具有对压力变化不敏感和智能温度补偿的功能.实验结果表明,20℃时传感器系数为K0=-129.5668 kg/m3,K1=-0.253 5×106(kg/m3)/s,K2=0.623 9×1010 (kg/m3)/s2,在700~900 kg/m3的测量范围内,综合测量精度为0.1%. 相似文献
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热激励谐振式硅微结构压力传感器闭环系统 总被引:5,自引:1,他引:4
讨论了一 执 式硅微结构压力传感器闭环系统。该谐振式硅微结构压力传感器以方形硅膜片作为一次敏感元件;硅梁作为二次敏感元件。在硅梁谐振子的中部设置一电阻,作为热激励单元;在梁的要部设置一压敏电阻,作为拾振单元。基于该夺式硅微结构压力传感器敏感机理,分析了信号的相互转换,给出传感器闭环系统实现的条件。 相似文献
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对一种以方形硅膜片作为一次敏感元件;硅梁作为二次敏感元件的硅谐振式压力微传感器进行了研究:建立了微传感器敏感结构的数学模型;敏感结构参数:方形膜边长4 mm,膜厚0.1 mm,梁谐振子长1.3 mm,宽0.08 mm,厚0.007 mm;对原理实验样件采用电热激励、压阻拾振方式作了开环测试,讨论了传感器的闭环系统. 相似文献
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基于谐振式硅微结构压力传感器幅、相频率特性的分析,利用北京航空航天大学微传感器实验室研制的谐振式硅微结构传感器开环测试系统的测试实验结果和Matlab实验数据处理与拟和分析计算,建立了微传感器的二阶模型.该模型排除了未知相位延迟的影响,从幅值和相位混合的测试数据中精确计算出谐振频率、品质因数以及相位特性,为闭环测试系统的研制提供了依据. 相似文献
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谐振筒式密度计的测量原理为谐振筒的谐振频率会随筒内液体密度的变化而变化,从而通过测量其谐振频率来达到测量其密度的目的。但由于低品质因数谐振筒在谐振频率附近的幅度与其他频率的幅度区分度太小,导致谐振难以实现。因此如何使低品质因数谐振筒达到谐振状态并测得其谐振频率,是谐振筒式燃油密度传感器激励系统的关键问题。激励系统以DSP为主控芯片,运用椭圆拟合的方法解决了低品质因数谐振筒式密度计激励系统的关键技术问题-增益测量和相位测量,运用原位计算节省了DSP大量的内存空间,同时运算量又较小。仿真结果表明,增益测量精度优于0.05%,相位测量精度优于0.05%,高于实际需要。系统在测量并记录了增益、相位差之后,利用相关算法实现了自动增益调节和自动相位调节,并实现了谐振筒的谐振,测得了其谐振频率。 相似文献
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扭转谐振模态微悬臂梁低能耗、高品质因数的特性,使它比传统的弯曲模态悬臂梁拥有更高的灵敏度和分辨率.将微传感器加工技术和生物检测技术相结合,利用扭转谐振模态微悬臂梁传感器对生物素和亲和素的特异性反应进行检测,结果传感器的灵敏度为0.9 pg/Hz,分辨可达到49 fg.本文还着重介绍了为谐振梁传感器设计的以锁相环(Phase-Locked Loop简称PLL)为核心的闭环接口电路,分析了悬臂梁和电路在闭环系统中的工作特性,并探讨了解决谐振式传感器在使用中常见的稳定性差、噪声干扰强等问题的方法. 相似文献
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Zs. Kádár A. Bossche P.M. Sarro J.R. MollingerAuthor vitae 《Sensors and actuators. A, Physical》1998,70(3):94-232
The present paper introduces a magnetic-field sensor based on a resonating single-crystal silicon structure. The excitation of the resonator is achieved by the Lorentz force generated by a sinusoidal current flowing through a rectangular coil deposited on the surface of the structure. The amplitude of the vibration, which is proportional to the magnetic field, is detected by sensing capacitors. Because of the high-quality factor of the resonator, a lower detection limit of 1 nT, or even smaller might be realised when the device is vacuum-packaged. This paper describes the working principle, the fabrication procedure as well as open- and closed-loop measurement results. 相似文献
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高分子线团中特定基团分布的分析方法 总被引:1,自引:0,他引:1
目的:描述高分子线团中特定基团的分布情况。方法:以线团质心和第i个特定基团的质心的连线为轴线,以适合的半径R做一虚拟圆柱,从线团质心开始,沿轴线方向,以合适的步长将圆柱分成若干个小圆柱,统计每一个小圆柱中的原子个数,根据小圆柱的原子个数确定线团在该方向的边缘,从而确定基团的相对位置。研究所有的特定基团后,就可求出起分布。结果:将该方法应用到乙烯-苯乙烯共聚物中苯环侧基的分析中,结果表明苯环主要位于线团的外部,苯乙烯含量高时,线团内部的苯环含量增加。结论:该方法可以准确描述高分子线团中特定基团的分布。该方法也可用于表征支化点的位置。 相似文献
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Hutomo Suryo Wasisto Qing Zhang Stephan Merzsch Andreas Waag Erwin Peiner 《Microsystem Technologies》2014,20(4-5):559-569
A closed-loop circuit is developed in this work for tracking the resonant frequency of silicon microcantilever mass sensors. The proposed closed-loop system is mainly based on a phase-locked loop (PLL) circuit. To lock onto the resonant frequency of the resonator, an actuation signal generated from a voltage-controlled oscillator is fed back to the input reference signal of the cantilever sensor. In addition to the PLL circuit, an instrumentation amplifier and an active low-pass filter are connected to the system for gaining the cantilever output signal and transforming a rectangular PLL output signal into a sinusoidal signal used for sensor actuation, respectively. To demonstrate the functionality of the system, a self-sensing silicon cantilever resonator with a built-in piezoresistive Wheatstone bridge is fabricated and integrated with the circuit. A piezoactuator is employed to actuate the cantilever into resonance. From the measurement results, the integrated closed-loop system is successfully employed to characterize a 9.4 kHz cantilever sensor under ambient temperature cross-sensitivity yielding a sensor temperature coefficient of ?32.8 ppm/°C. In addition to it, the sensor was also exposed to exhaled human breath condensates and e-cigarette aerosols to test the sensor sensitivity obtained from mass-loading effects. With a high frequency stability (i.e., a frequency deviation as low as 0.02 Hz), this developed system is intended to support the miniaturization of the instrumentation modules for cantilever-based nanoparticle detectors (CANTORs). 相似文献
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Wenshan Wei Weilong You Chuanguo Dou Xiaofei Wang Heng Yang 《Microsystem Technologies》2016,22(4):811-816
A central symmetrical design in double ended tuning fork (DETF) resonator is demonstrated to remove the high feedthrough signal. The equivalent electrical simulation model for piezoresistive sensing is first built to illustrate that the location arrangement of connection pads plays a decisive role in the response of the high frequency resonators. Both of the symmetrical design and asymmetrical design of the DETF that resonating at 3.1 MHz are fabricated and tested to verifiy that with the same dimension of the resonator structrue, the symmetrical design can help to cancel the feedthrough signal from the output of the wheastone bridge. 相似文献