Applied Mechanics and Materials Vols. 568-570

Abstract: The gas-liquid two-phase flow exists widely in nature and in our daily life, to realize the phase flow does not separate online measurement has become an important subject in the study. Through CFD simulation experiment, the optimal structure of inner and outer tube differential pressure flowmeter prototype. Through the analysis of the experimental data, comparison of the classical theoretical models found high Chishlom prediction model error is minimum. Moisture the modified model, the relative error of measurement is better than in the range of experiment 5%.

Abstract: Ground pressure monitoring systems have been installed in many mines; there are several methods which have been used in this monitoring system, in this paper the key technologies are elaborated about ground pressure monitoring, which includes displacement sensors, the choice of power supply, the arrange of network, the serial-Ethernet convertor and human-machine interface’s design.

Abstract: Magnetometers-aided MINS could solve roll angle measurement of air vehicle at fast spinning rate, but magnetometers were easily disturbed and had measuring error, so it was necessary to establish tri-axial magnetometer correction system for magnetometers-aided MINS navigation system. Based on LabWindows/CVI and MATLAB fuzzy programming, earth magnetic field and ellipsoid fitting model were built to complete magnetometers correction system and its virtual instrument. On that basic, magnetometers-aided MINS navigation system and its virtual instrument were established. Results of correction and non-correction magnetometers-aided MINS navigation test showed that the magnetometers correction system can compensate the error of interference, measuring and so on, furthermore geomagnetic attitude computing become more accurate and the higher precision of position and velocity for magnetometers-aided MINS system. All of them are significant for engineering and products.

Abstract: The networked and smart interface standards have very important role for underground water monitoring system integration, dynamic information real time acquisition and sharing. Firstly this paper introduces several interface standards as IEEE 1451, and field of environmental monitoring in the popular serial data communication interface standard SDI-12 in the Europe and the United States, then summarize their architectures, main contents and application situation,and then analyze their advantages and questions existing in the standards respective. Introduction groundwater level, water temperature automatic monitoring and remote management system implementation method based on the SDI-12 standard form. Finally puts forward interface standards which could be applied to the underground water monitoring system.

Abstract: Ion Mobility Spectrometer (IMS) is an effective instrument for detecting narcotics and explosives. Signal average IMS (SA-IMS) is used widely because it is relatively convenient to build. SA-IMS is low efficient in utilization of sample ions (1%), while FT-IMS is relatively high (25%). However, detailed discussions of several important parameters, such as frequency sweeping range, frequency sweeping intervals and gating function distortion, have not been made in previous studies. In this article, we build a numerical simulation model of FT-IMS, with which we appraised these parameters respectively. Main job of this article is done with MATLAB. We also propose several guidelines in building FT-IMS.

Abstract: Air core transformer is an essential part of mass spectrometer. Test coil is often used to measure its resonant frequency with the advantages of easy installation and high sensitivity. However, the influence of test coil while it is installed close to the working coils on the transformer is not studied before. To reveal the influence of test coil and determine the right position to install, two experiments using test coil and opened probe respectively for the measurement are conducted. Since the opened probe has little load effect on the original transformer impedance system, it can be used to validate the influence of test coil. By comparing the two experimental results, we find that the right position to install the test coil is on the further side of the primary coil to the secondary coil. This work allows us to integrate the test coil with the air core transformer to monitor the resonant frequency in real-time.

Abstract: The feasibility and reliability of the retrieval of true temperature and spectral emissivity based on continue measurement data iteration algorithm is explored for multi-wavelength pyrometer. The proposed algorithm is derived theoretically, which can obtain the true temperature by iterative process of searching a team of spectral emissivity correctly. Simulation and experimental results indicate that a fairly reasonable representation of true temperature and spectral emissivity distribution can be obtained using the continue measurement data iteration method. The method has advantages of simplicity, rapidity, and suitability for on-line true temperature measurement by pyrometer.

Abstract: Aiming at the problem of modeling and compensation of the fiber optic gyroscope (FOG) drift caused by temperature, a novel compensation method for FOG temperature drift based on transformed unscented Kalman filter (TUKF) is proposed. Elman network with faster convergence speed is used to modeling and TUKF algorithm is adopted to train the weights of Elman network, which effectively solves the problem of numerical instability. The results prove that the proposed method has higher precision compared with Elman network and IUKF network models. By using the TUKF algorithm, the root mean square errors (RMSE) are improved by 60%  in temperature rise period and 50.5% in fall period.

Abstract: Free-space methods for EMC antenna calibrations at Open Area Test Site (OATS) are not suitable for monopole antennas because of corresponding large wavelengths. The Equivalent Capacitor Substitution Method (ECSM) is adopted in ANSI and CISPR standards. One of major uncertainty factors of ECSM is the accuracy of capacitance. A novel capacitance extraction method based on full-wave impedance modelling is proposed in this paper, which is more accurate than conventional analytical formulae and experienced values, especially for practical monopole antennas, with a telescopic rod, or with a finite ground plane. A projection based model order reduction method is then utilized to achieve a compact macro-model. The capacitance value can be determined from the input impedance which is given by the macro-model output. The scheme and computational methodology of a developed calculation tool are introduced, together with some practical calibration data which indicates the effectiveness of the proposed methods.

Abstract: A highly automated way for serial data validation is presented in this paper. The method is based on widely available Digital Storage Oscilloscope (DSO) and low cost Personal Computer (PC). Instrument automation with data capturing and processing is demonstrated. The method is able to process large amount of high speed serial data. The validation procedure is shown in this paper; two instrument automation control protocols are described; data processing algorithm in Python language is also discussed.