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介绍了超低频主动隔振控制中常用的位移传感器的类型、工作原理、结构特点及适用范围。对影响静电悬浮加速度计测量精度的振源进行了详细分析,并对静电悬浮加速度计测量频段范围内的振动幅值作出了理论计算。对设计研制的线变量差动位移传感器进行了测试,结果表明:该传感器对振动频率在10-4~100Hz范围内的低频振动信号具有非常理想的拾振效果。 相似文献
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基于二次谐波脉冲幅值法的磁通门传感器 总被引:3,自引:0,他引:3
简述了磁通门现象的数学模型和工作原理。针对磁通门传感器在提高带宽时噪声也会随之增大的问题,应用二次谐波选择法设计了磁通门信号处理电路,试制了一种宽带低噪声磁通门传感器,很好地解决了提高带宽和降低噪声之间的矛盾。经测试,样机带宽可以达到700 Hz以上,10 Hz处的噪声小于10 pT/Hz,线性度为0.2%。 相似文献
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磁阻型弱磁传感器特性自动测试系统 总被引:1,自引:0,他引:1
随着磁阻型弱磁传感器的深入研究和广泛应用,方便、快速的测量传感器低频噪声、灵敏度、非线性等特性已成为研究其低频弱磁场测量能力的基础。设计开发了一套弱磁传感器特性自动测试系统,其自身的噪声平方根谱密度小于槡5 nV/Hz(在10kHz)。它包括亥姆霍兹线圈、惠斯登电桥和低噪声放大器、磁屏蔽桶、高精度数据采集卡和PC等硬件模块,采用互相关功率谱分析方法得到传感器低频噪声,通过传感器输入输出特性曲线得到其灵敏度和非线性等参数。利用该系统对商业化巨磁阻传感器AA002进行了测试,得到其在6 V供电时噪声平方根普密度约为槡10 nV/Hz(在10 kHz),线性范围内的灵敏度为3.35 mV/(G.V-1)。结果表明该系统为研究和分析磁阻型弱磁传感器的特性提供了一种有效的检测手段。 相似文献
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以硅光电池作为安平仪敏感元件的光电式角度传感器的工作原理,设计了自动电子安平仪的硬件电路,介绍了软件系统的主要设计任务和总体思路,采取数字滤波滤除了干扰信号,采取PID控制算法提高了系统的性能指标,通过实验对自动电子安平仪传感器的性能进行了测试,最后对样机进行了测试,结果表明自动电子安平仪两个主要指标,即安平精度和安平时间基本达到设计要求. 相似文献
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为满足对振动环境下10 Hz以下低频小量程加速度信号的高精度测量需求,提出了一种基于石英微工艺的新型窄带宽MEMS加速度计,其敏感元件采用变间距式差分电容梳齿结构。采用有限元分析手段,对敏感元件质量块尺寸、梳齿长度、U型梁刚度、盖板结构、阻尼和带宽等参数进行了综合优化设计。敏感元件采用石英晶片经湿法腐蚀体工艺制作,加速度计样机经过了实际性能测试和环境适应性试验,带宽为8.9 Hz,非线性度约为0.7%,可以满足飞行器小量程低频加速度参数的测量需求。 相似文献
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为了克服现有电磁式涡轮流量计的量程小,易受电磁干扰的缺点,本文设计了一种双圈同轴式光纤的涡轮流量智能检测系统。该测试系统由三大模块组成,双圈同轴式的光纤传感器作为信号拾取工具,硬件电路对信号进行预处理,TMS320F2812 DSP对信号进一步软件处理。经过实验验证,该测试系统在5-300Hz的测量范围内,测量误差小于0.5%。因此,该测试系统具有较高的测量精度和可靠性,这为光纤涡轮流量计的样机制作提供了重要依据。 相似文献
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实现低频速度传感器的低频扩展在精密减振领域有着重要的意义,本研究提出基于负刚度结构的低频速度传感器,负刚度结构由两组电磁弹簧组成,采用正负刚度并联原理以实现传感器的低频扩展。首先采用安培电流模型建立电磁弹簧数学模型,分析参数对电磁负刚度特性的影响规律并提出负刚度结构优化策略,另外通过调整负刚度结构中线圈电流大小实现传感器固有频率可调。通过数值仿真分析负刚度的非线性影响以及在不同激励幅值和激励频率下传感器的低频响应特性。结果表明负刚度非线性影响可以忽略,当负刚度结构通入电流为0.9A时,传感器固有频率为4Hz,而在通入电流为1A时,传感器固有频率为1Hz,有效地降低速度传感器的测量下限。 相似文献
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报导了一种建立在弹片受迫振动基础上,利用光学三角技术制成的光纤振动传感器。该传感器线性工作范围0.8mm峰峰值,分辨率为10μm,可测的振动频率范围为几百Hz。该传感器体积小,绝缘性好,可用于大型电力设备测量其交流振动。 相似文献
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《Ergonomics》2012,55(7):1431-1444
Abstract An experiment is described in which eight subjects performed three simple tasks (A, B and C) in static conditions and during exposure to whole-body vertical (z-axis) vibration at 0-5 and 40 Hz, at an acceleration magnitude of 2-1 ms-2 r.m.s. All subjects performed all conditions with and without an arm support. The objective was to explore the mechanisms that may cause disruption of manual control performance during vibration exposure. With task A subjects simply held a control with no visual feedback of activity at the control. With task B, subjects used the control to hold a controlled element stationary on a display. Task C was the same as task B, except that subjects had improved visual feedback of movement of the controlled element. Results showed that both 0-5 and 40 Hz vibration caused significant increases in control activity at frequencies of up to about 1 Hz compared with the condition without vibration. With visual feedback in task C, subjects were able to detect drifting of the controlled element on the display and introduced compensatory control activity at frequencies above about 0 2 Hz. The arm support reduced the magnitude of vibration transmitted to the control at 4-0 Hz, but did not otherwise change the results. 相似文献
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Zhuoqing Yang Wenguo Chen Guifu Ding Yan Wang Hong Wang Xiaolin Zhao 《Microsystem Technologies》2016,22(3):503-513
A micro-machined passive vibration threshold sensor with a compliant stationary electrode has been designed, simulated and characterized. Bridge-type elastic beams as the compliant stationary electrode is adopted to improve the contact effect of the vibration threshold sensor and prolong its contact time. The dynamic contact between the two electrodes of the micro-machined vibration threshold sensor is simulated and analyzed by finite-element method (FEM). It’s indicated that a ‘skip contact’ phenomenon occurred during the switching on, which has been described and successfully explained in this paper. Deformations and stress distributions of the compliant electrode during contact under 55 g half-sine applied shock acceleration is also simulated. An all-metal cap that can undergo 6.08 × 105 Pa has been designed and fabricated by UV-LIGA process for package of the vibration threshold sensor. A drop hammer test of the fabricated vibration threshold sensor has been done, which is in accordance with the FEM simulation of dynamic contact process. The measured response time of the threshold sensor is about 0.3 ms under 55 g applied acceleration and two contact times in the skip contact are 16 and 4 µs, respectively, which are in agreement with simulated results. The obtained natural frequency of the vibration threshold sensor by a vibration test is about 810 Hz in the first model, which also agrees with the model. 相似文献
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为了早期发现电力变压器的振动故障问题,需要选择有效位置对变压器的振动状态进行检测.针对电力变压器铁芯-绕组振动特性,通过有限元分析,仿真得到铁芯-绕组测点位置.以型号为S13-12500/35型油浸式无励磁调压35 kV电力变压器为试验对象,将光纤Bragg光栅(FBG)振动传感器安装于铁芯-绕组的测点位置,对不同负载下变压器振动信号进行检测与频谱分析,结果表明:变压器振动信号频率集中在100 Hz及其倍频处;在80%,90%,100%负载下,幅频信号100 Hz处的振动幅值随着变压器负载的增大而增大. 相似文献
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In this paper, a 3D pose attitude estimation system using inertial sensors was developed to provide feedback motion and attitude information for a humanoid robot. It has a very effective switching structure and composed of three modules, a motion acceleration detector, a pseudo-accelerometer output estimator, and a linear acceleration estimator. The switching structure based on probability enables a tactful feedback loop for the extended Kalman filter inside the sensor system. Specially designed linear-rotation test equipment was built, and the experimental results showed its fast convergence to actual values in addition to its excellent responses. The output of the proposed 3D sensor can be transmitted to a humanoid at a frequency of 200 Hz. 相似文献
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Exposure to high frequency (kHz) vibration from impact power tools is overlooked in the ISO 5349-1 risk prediction for acquiring Hand Arm Vibration Syndrome. The biological effects of high frequency, power tool vibration have not been adequately studied. We characterized the magnitude and transmissibility of riveting hammer vibration in a rat tail model using a light weight piezoelectric sensor. The performance of the newly-introduced piezoelectric sensor was validated by showing its similarities to the previously published laser vibrometer. ISO 5349-1 frequency weighting revealed major risk from the 35 Hz component of the riveting hammer vibration, whereas the weighted values of the kHz components were not calculated to reach exposure action value in 24 h– However, the unweighted acceleration magnitudes at 12.4 and 16.3 kHz were about 10 and 50 times larger than the unweighted acceleration peak observed at 35 Hz. A transmissibility of <1 was calculated for 12.4 and 16.3 kHz, indicating tissue absorbance, while 35 Hz exhibited a transmissibility of 9.05, suggesting tissue resonance. The largest absolute change in acceleration was at 12.4 and 16.3 kHz, implicating that a considerable amount of high frequency vibration energy was absorbed by the tissue. A progressive reduction in intact sensory nerve endings was observed in the tissue when increasing vibration exposure from 1 min to 12 min. 相似文献
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This study seeks to examine human vibration response using a musculoskeletal model that appropriately considers stretch reflex. The stretch reflex is modeled with a feedback control approach, and integrated into a generic musculoskeletal model to study the active muscle forces during seated whole body vibration. The model is used to investigate the effects of stretch reflex gain, vibration frequency and vibration magnitude on transmissibility from the seat to upper body and lower body and on muscle activations.The overall model is validated by comparison with thoracic and lumbar muscle activities measured in human participants during whole body vibration. The simulation results were consistent with the experimental results that the peak transmissibility occurred at resonance frequency of 5–6 Hz, and were in line with other experimental studies that found a primary resonance of 4–6 Hz. Furthermore, the peak normalized Electromyography (EMG) level accorded with the activation level for both thoracic and lumbar regions. What's more, an increase of primary resonance frequency was observed with increasing gains of stretch reflex. In contrary, the peak seat transmissibility of the upper body and lower body had a significant reduction.The major contribution of this model is that the proposed stretch reflex model provides a useful method to consider muscle active response in whole body vibration simulation. This may be used in future studies to better understand how stretch reflex affects spinal loading in a variety of conditions. 相似文献