共查询到18条相似文献,搜索用时 156 毫秒
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谐振式光纤陀螺的数字检测方案及其优化设计 总被引:1,自引:1,他引:0
提出了一种基于 DSP 芯片实现的双频率数字调制谐振式光纤陀螺系统的闭环检测方案。在此方案中,利用带通滤波器从探测器的输出光强信号中提取其基波频率的正弦信号,通过相关检测原理去掉干扰的噪声,并利用低通滤波器提取与探测器输出光强幅度直接成正比的直流信号,将其转换成相应的谐振频差,利用此频差即可求得陀螺的旋转角速度。此方案检测线路简单,操作方便,基于 DSP 芯片的实现则大大提高了系统处理速度。同时,还利用 Matlab 软件对检测系统中的滤波器参数进行了优化设计,提高了系统的检测精度。 相似文献
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本文首先通过正弦波调制下干涉信号光强分析解调出光纤陀螺的输出信号,进而得出残余强度调制存在的情况下陀螺输出信号的变化情况,同时,通过分析陀螺信号的变化说明残余强度调制对光纤陀螺性能的影响与陀螺精度要求有关,精度越高,其影响越明显.其次,具体分析了数字闭环光纤陀螺受残余强度调制影响的情况下,其解调输出电压变化引起的数字阶梯高度变化,并通过残余强度调制系数与数字阶梯高度的关系式,说明了残余强度调制对光纤陀螺零偏和标度因数的影响.最后,对所得出的残余强度调制系数与光纤陀螺标度因数稳定性的关系进行了Matlab仿真,通过仿真结果,更进一步说明残余强度调制对数字闭环光纤陀螺标度因数稳定性的影响. 相似文献
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本文讨论了舰艇辐射噪声的特性.运用冲激响应不变法来设计了一个IIR数字一阶低通滤波器,并用此滤波器对高斯白噪声进行滤波,滤波器的输出能很好地模拟舰艇辐射宽带连续噪声,此输出信号的功率谱在高频端以每倍频程6分贝的斜率下降.运用直接数字信号合成技术产生多个低频线谱信号,并将它与宽带连续噪声相加,从而来模拟舰艇辐射的低频线谱. 相似文献
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为了提高谐振式光学陀螺(Resonant optic gyro,ROG)数字检测系统的信噪比,消除解调曲线中的高频噪声,降低FPGA资源占有率,提出并设计了一种惯性数字低通滤波器.该滤波器能够满足ROG数字检测系统在40 MHz的高采样率下,低通截止频率连续,阶数可调,FPGA内部消耗资源少的要求.理论分析了惯性滤波器的函数模型,给出了该滤波器的数字实现过程,仿真并测试了截止频率为194.38 Hz,0.189Hz下的幅频和相频曲线.实验表明:设计的数字滤波器幅频、相频特性优良,FPGA资源占用率仅为0.09%,阶数及截止频率调节简便,满足了数字锁相放大器内低通滤波器的设计要求. 相似文献
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文章中讨论了水中目标一船体辐射噪声的特性。运用冲激响应不变法来设计IIR数字一阶低通滤波器,并用此滤波器对高斯白噪声进行滤波,滤波器的输出能很好地模拟船体辐射宽带连续噪声,此输出信号的功率谱在高频端以6dB/oct的斜率下降。运用直接数字信号合成技术产生多个低频线谱信号,并将它与宽带连续噪声相加,从而来模拟船体辐射的低频线谱。 相似文献
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光纤陀螺性能数字评价系统的可视化研究 总被引:2,自引:0,他引:2
开发了一种接收并处理光纤陀螺信号的数字评价系统,它通过计算光纤陀螺的零漂、零偏重复性、标度因数等来评价光纤陀螺的性能。在Windows平台下采用VC 设计的数字采集处理系统能够实时控制进程、高速收发数据以及用图形和文字可视化显示其结果,并引进了帧结构来减少传输误差,使系统的可靠性增加,误码率也同时降低。 相似文献
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针对光纤陀螺在面板堆石坝面板挠度监测中易受到噪声干扰,难以准确提取反映结构变形特征信号的实际问题,提出一种基于最小二乘平滑滤波与CEEMDAN混合降噪的方法。该方法运用CEEMDAN将光纤陀螺实测信号进行分解,得到一系列IMF分量。分别对每一阶IMF分量进行傅里叶频谱分析得到幅值谱图和幅值的方差,根据幅值方差的大小判断噪声IMF分量与有用信号IMF分量的分界,结合最小二乘平滑滤波对噪声IMF分量进行降噪。最后将降噪后的IMF分量与有用信号IMF分量进行重构,得到降噪后的光纤陀螺信号。通过对仿真信号和水布垭面板堆石坝面板挠度监测的实测数据进行分析,该方法能有效滤除噪声信号,准确提取反映结构变形的特征信号,验证了该方法对实际工程中光纤陀螺测量信号降噪的可行性和适用性。 相似文献
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The linearity of an efficient polar transmitter architecture, with a 1 bit oversampled delta?sigma (DS) modulating the envelope signal, depends, to a high degree, on low-pass envelope filtering. This filter is compulsory to attenuate the DS quantisation noise. A high cut-off frequency results in more noise being included. In contrast, using a filter with a low cut-off frequency results in attenuation of the information content of the envelope signal. Either way, the result is unwanted spectral regrowth. By pre-emphasising the envelope signal, the filter?s attenuation of the information is mitigated. The pre-emphasis is implemented by a digital pseudo-derivative high-pass filter, with inverse magnitude characteristics of the analogue low-pass filter, within a limited interest band. Consequently, the low-pass filter can be designed with a lower cut-off frequency to attenuate more of the DS modulator noise, and the modulator can switch at lower frequencies. With this technique, the WLAN output spectrum, at the critical 30 MHz offset corner frequency, is improved by 12.5 dB, considering a second order DS sampling at 1.28 GHz. The technique was verified with an experimental setup and the behaviour agrees well with simulations. 相似文献
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A fiber optic Michelson sensor was embedded in composite beams to sense the internal strain and points of failure of the composite structures. The bending deformation and matrix cracking were investigated by four-point bending tests of cross-ply composite beams with the embedded fiber optic sensor. The failure points of composite beams were detected by using both a PZT sensor and a fiber optic sensor in order to investigate the fiber optic failure signals. The failure due to matrix cracks in a composite beam was confirmed by the edge replica method. The digital processing of the fiber optic signal was carried out to determine the strains and failure points of composite beams. The failure points were observed from the processed failure signal by high-pass filtering. The initial failure strain of the composite beam was measured and processed from the fiber optic strain signal after low-pass filtering. 相似文献
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《IEEE transactions on instrumentation and measurement》1966,15(1):33-38
A comparison of the ideal integrator and low-pass filters has been made. Many experimenters use an integrator to filter out high-frequency noise from their data, whereas a properly designed low-pass filter will remove more noise and distort the signal less. Viewed as a low-pass filter, the integrator is superior to the RC filter but inferior to higher order filters. An integrating digital voltmeter (DVM) integrates and samples the input signal. If the signal has a varying component and is mixed with noise, it would be more accurate to use a low-pass filter followed by a sampler, than the integrating DVM. 相似文献
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This work reports on the design of novel closed-loop control systems for the sense mode of a vibratory-rate gyroscope based on a high-order sigma-delta modulator (SigmaDeltaM). A low-pass and two distinctive bandpass topologies are derived, and their advantages discussed. So far, most closed-loop force-feedback control systems for these sensors were based on low-pass SigmaDeltaM's. Usually, the sensing element of a vibratory gyroscope is designed with a high quality factor Q to increase the sensitivity and, hence, can be treated as a mechanical resonator. Furthermore, the output characteristic of vibratory rate gyroscopes is narrowband amplitude-modulated signal. Therefore, a bandpass SigmaDeltaM is a more appropriate control strategy for a vibratory gyroscope than a low-pass SigmaDeltaM. Using a high-order bandpass SigmaDeltaM, the control system can adopt a much lower sampling frequency compared with a low-pass SigmaDeltaM while achieving a similar noise floor for a given oversampling ratio (OSR). In addition, a control system based on a high-order bandpass SigmaDeltaM is superior as it not only greatly shapes the quantization noise, but also alleviates tonal behavior, as is often seen in low-order SigmaDeltaM control systems, and has good immunities to fabrication tolerances and parameter mismatch. These properties are investigated in this study at system level 相似文献