共查询到20条相似文献,搜索用时 877 毫秒
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本文介绍了空间三维测量中一种新的测量方式和测量仪器,目的是为不同需求的市场提供更多的测量手段,增强三坐标测量机的功能,提高工作效率,为飞速发展的工业提供可靠的保证。这种测量机将技术较为成熟的三维测量技术与具有国际先进水平的数字成像技术有机地结合在一起,充分利用了三坐标测量机定位精度高,操作方便等特点,和数字成像技术采集速度快,数据处理能力强的特点。这种测量机是一种开拓性、实用性和综合性很强的的测量仪器。 相似文献
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本文介绍了数字多用表测量电阻的原理 ,分析了测量大电阻时读数不稳定及误差产生的原因 ,提出了如何在测量中提高仪器的抗干扰能力 相似文献
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详细介绍了利用GPS RTK技术与数字测深仪联合进行水下地形测量的工作原理,巢湖航道水下地形测量,讨论了测量设备的选择、仪器参数设置、数据检验和测量过程中应注意的事项。 相似文献
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DDS-11A数字式电导率仪是实验室测量水溶液电导率的必备仪器,它采用31/2位LED数字显示,读数直观清晰,广泛用于化工、医药、卫生、环境监测、污水处理等部门,还可用于测量纯水或高纯水的电导率,仪器内部的组成框图如图1所示。 相似文献
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信号时域平均处理的新算法 总被引:10,自引:3,他引:7
时域平均是从混有噪声的复杂周期信号中提取感兴趣周期分量的常用方法,但在其实施时往往由于周期截断误差的存在而不能取得满意的效果。本文提出了信号时域平均处理的新算法,基本上解决了周期截断误差对平均结果的影响问题。分析验证说明:新算法比过去的旧算法效果好得多 相似文献
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《IEEE transactions on instrumentation and measurement》1979,28(1):46-54
Most radiometers utilize a calibration technique in which measurements of a known reference are subtracted from measurements of an unknown source so that common-mode bias errors are cancelled. When a radiometer is scanned over a varying scene, it produces a sequence of outputs, each being proportional to the difference between the reference and the corresponding input. The reference averaging technique presented herein employs a simple digital algorithm which exploits the asymmetry between the time-variable scene inputs and the nominally constant reference input by averaging many reference measurements to decrease the statistical uncertainty in the reference value. This algorithm is, therefore, optimized by an asymmetric chopping sequence in which the scene is viewed for more than one-half of the duty cycle (unlike the analog Dicke technique) Reference averaging algorithms are well within the capabilities of small microprocessors. Although this paper develops the technique for microwave radiometry, it may be beneficial for any system which measures a large number of unknowns relative to a known reference in the presence of slowly varying common-mode errors. 相似文献
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用积分平均法和黎卡提技巧,对偶数阶带阻尼项非线性微分方程研究获得一些新的振动准则,这些结果改进和推广了一些已有文献的性质.最后,我们给出实例以阐述本文结果的有效性. 相似文献
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《IEEE transactions on instrumentation and measurement》1977,26(3):254-257
In the statistical study of two-phase flow real-time control of experiments is often needed. Furthermore, in industrial processes involving boiling units control or two-phase gas-liquid transport control, real-time signal processing is required to check the status of two-phase flows. An instrument is described for the measurement of the fundamental characteristic parameters of two-phase flows. The measurement technique employs extensively high speed digital computation. It is based on a discrimination of the probe output signal into two signals, representing, respectively, a "bubble" flow and a slug flow. The parameters are measured on averaging times ranging from 10 ms to 104 s. Measurement errors and limitations of this high-resolution measurement technique are pointed out. Its utility in evaluating the fundamental statistical parameters of two-phase flows is demonstrated. 相似文献
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Stochastic averaging of quasi-integrable Hamiltonian systems under bounded noise excitations 总被引:1,自引:0,他引:1
A stochastic averaging method is proposed to predict approximately the response of quasi-integrable Hamiltonian systems to bounded noise excitations. Two cases of external resonance only and both internal and external resonances are considered separately. The reduced averaged Fokker–Planck–Kolmogorov equation is solved by using the combination of the finite difference method and the successive over relaxation method. An example of two coupled Duffing oscillators under bounded noise excitations is given to illustrate the application of the proposed procedure. It is shown that the analytical results agree well with those from digital simulation of original system. 相似文献
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提出将气体静压轴系径向节流孔所在截面简化成平面汇交力系,并与边界约束条件一起构成误差方程,应用静力学的理论求解了一些典型情况,并推导出了典型状态下的误差均化值,发现其与过去的实验结果相符且得到了很有意义的结果,从而为进一步建立精确的数学模型进行仿真分析提供了必要的基础. 相似文献
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A method of predicting the response of randomly excited nonlinear systems, with nonlinearity both in damping and stiffness is presented. The method is based upon the stochastic average technique which is a generalization of the Krylov Bogoliubov deterministic averaging technique. The practical usefulness of the method is established through its application to the Bouc exponentially hysteretic model. It is observed that while the exponentially hysteretic system has some features in common with the bilinear hysteretical system, it also has some remarkable differences. 相似文献
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周期测量误差对周期信号时域平均处理结果的影响 总被引:6,自引:3,他引:3
时域平均处理是从混有噪声的复杂周期信号中提取简谐分量的有效方法之一。本文从时域平均处理的基本原理出发,探讨了时域平均处理中周期测量误差对简谐分量幅值和相位的影响,并给出了时域平均处理后信号各阶简谐分量幅值衰减量和相位变化与周期测量误差、平均次数以及分量阶次之间的关系式。该关系式较复杂不便于工程应用,本文进一步用简单函数线性组合逼近的方法,得出了简化关系式。仿真和工程实例表明,该简化关系式适合工程应用 相似文献