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Measuring Method of Eyes Diopter Based on Image Measuring Technology

电子学报(英文版) 2010年第3期19卷 473-476页

作者： MA Qiaomei XUE Zhongjin ZHU Linquan Key Laboratory of Instrumentation Science and Dynamic Measurement (Ministry of Education) North University of China Taiyuan China National Key Laboratory for Electronic Measurement Technology North University of China Taiyuan China

Measuring system of eyes diopter is designed with diopter adjustment theory of visual optics and image measuring technology. Measuring methods of presbyopia, myopia, hyperopia and astigmatism are discussed. A link image is projected to the measured eye ground, and then the reflection image is measured from eye ground by CCD device. Finally, size and shape of the image are automatically recognized by computer. Far point diopter and near point diopter are measured according to the method. Far point diopter is defined as the fitting glasses parameters of hyperopia, myopia and astigmatism. Fitting glasses parameters of presbyopia are related to far point diopter and near point diopter. Calculation methods of fitting glasses parameters are given. Because measuring methods utilize advantages of subjective optometry and objective optometry, fitting glasses parameters may be quickly and accurately measured.

关键词：图像测量技术测量方法屈光度眼睛计算机识别拟合参数 CCD器件测量系统

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Signal processing for all fiber optical current transducer

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Journal of Central South University 2008年第S2期15卷 404-408页

作者：裴焕斗祖静陈鸿 School of Information and Communication Engineering North University of China Key Laboratory of Instrumentation Science and Dynamic Measurement North University of China Ministry of Education

The work principle of all fiber optical current transducer (AFOCT) was introduced. By analyzing the characteristic of photo-detector's output, a measurement and signal processing scheme based on sine wave modulation and demodulation was put forward for eliminating the influence of light intensity change and modulation degree change. A digital signal processing system and a calibration scheme were also advanced. The experimental data show that the mean ratio error is 0.016 74% for direct current and 0.035% for alternating current, and the correlation coefficient of linearity is up to 0.999 982 4, meeting the precision requirement of 0.2 grade. Stability experiments and temperature drift experiments show the AFOCT has a better stable capability.

关键词： fiber optical current transducer demodulation signal processing ratio error

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A cold ^(87)Rb atomic beam

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Chinese Physics B 2011年第12期20卷 322-327页

作者：王晓佳冯焱颖薛洪波周兆英张文栋 Key Laboratory of Instrumentation Science and Dynamic Measurement Ministry of EducationNorth University of China State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instruments and MechanologyTsinghua University Joint Institute of Measurement Science (JMI) National Institute of Metrologia-Tsinghua UniversityBeijing 100084China

We demonstrate an experimental setup for the production of a beam source of cold 87Rb atoms. The atoms are extracted from a trapped cold atomic cloud in an unbalanced three-dimensional magneto-optical trap. Via a radiation pressure difference generated by a specially designed leak tunnel along one trapping laser beam, the atoms are pushed out continuously with low velocities and a high flux. The most-probable velocity in the beam is varied from 9 m/s to 19 m/s by varying the detuning of the trapping laser beams in the magneto-optical trap and the flux can be tuned up to 4× 10^9 s-1 by increasing the intensity of the trapping beams. We also present a simple model for describing the dependence of the beam performance on the magneto optical trap trapping laser intensity and the detuning.

关键词： continuous atomic beam unbalanced three-dimensional magneto-optical trap radiation pressure difference laser cooling and trapping

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A novel SOI pressure sensor for high temperature application

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Journal of Semiconductors 2015年第1期36卷 120-124页

作者：李赛男梁庭王伟洪应平郑庭丽熊继军 Key Laboratory of Instrumentation Science & Dynamic Measurement (North University of China) Ministry of Education Ministry of Education and Science Technology on Electronic Test & Measurement Laboratory. Department of Electronic Science and technology North University of China

The silicon on insulator（SOI） high temperature pressure sensor is a novel pressure sensor with highperformance and high-quality. A structure of a SOI high-temperature pressure sensor is presented in this *** key factors including doping concentration and power are analyzed. The process of the sensor is designed with the critical process parameters set appropriately. The test result at room temperature and high temperature shows that nonlinear error below is 0.1%, and hysteresis is less than 0.5%. High temperature measuring results show that the sensor can be used for from room temperature to 350℃ in harsh environments. It offers a reference for the development of high temperature piezoresistive pressure sensors.

关键词： SOI high temperature pressure sensor doping concentration power

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A novel algorithmic method for piezoresistance calculation

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Journal of Semiconductors 2014年第5期35卷 60-63页

作者：洪应平梁庭葛冰儿王伟郑庭丽李赛男熊继军 Key Laboratory of Instrumentation Science & Dynamic Measurement (North University of China) Ministry of Education Ministry of Education and Science Technology on Electronic Test & Measurement Laboratory Department of ElectronicScience and technology North University of China

A novel algorithmic method, based on the different stress distribution on the surface of thin film in an SOI microstructure, is put forward to calculate the value of the silicon piezoresistance on the sensitive film. In the proposed method, we take the Ritz method as an initial theoretical model to calculate the rate of piezoresistance ΔR/R through an integral （the closed area Ω where the surface piezoresistance of the film lies as the integral area and the product of stress σ and piezoresistive coefficient π as the integral object） and compare the theoretical values with the experimental results. Compared with the traditional method, this novel calculation method is more accurate when applied to calculating the value of the silicon piezoresistance on the sensitive film of an SOI pieoresistive pressure sensor.

关键词： piezoresistance integral piezoresistive pressure sensor accuracy

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Research on multichannel test device of missile fuze

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Sensors and Transducers 2014年第5期171卷 250-255页

作者： Zhen, Guoyong Shan, Yanhu Wei, Yiran National Key Laboratory for Electronic Measurement Technology North University of China Taiyuan China Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education North University of China Taiyuan China

This paper introduces the design of multichannel acquisition circuit based on FPGA which samples and records the Doppler signals, ignition signal and the working condition of fuze security enforcement agencies of missile fuze in real-time in the test of high speed dynamic intersection. Furthermore, for the problem of increasing number of sample channel which causes the complexity of the multiplexer control, a general programmable channel switching method is proposed based on FPGA. In the method, FPGA is the control core, and using the internal ROM resource effectively simplifies the complexity of channel switch in the multichannel acquisition system. This paper analyzes the acquisition system design, and describes the design of hardware circuit and analog switch address coding in detail. The test result shows that the acquisition circuit meets the design requirements with high sampling precision and application value. © 2014 by IFSA Publishing, S. L.

关键词： Field programmable gate arrays (FPGA)

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measurement of wireless pressure sensors fabricated in high temperature co-fired ceramic MEMS technology

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Journal of Zhejiang University-science C(Computers and Electronics) 2013年第4期14卷 258-263页

作者： Ji-jun XIONG Shi-jun ZHENG Ying-ping HONG Jun LI Ying-lin WANG Wei WANG Qiu-lin TAN Key Laboratory of Instrumentation Science & Dynamic Measurement North University of China MOE Science and Technology on Electronic Test & Measurement Laboratory North University of China The Second Research Institute of China Electronics Technology Group Corporation

High temperature co-fired ceramics(HTCCs) have wide applications with stable mechanical properties,but they have not yet been used to fabricate *** introducing the wireless telemetric sensor system and ceramic structure embedding a pressure-deformable cavity,the designed sensors made from HTCC materials(zirconia and 96% alumina) are fabricated,and their capacities for the pressure measurement are tested using a wireless interrogation *** the fabricated sensor,a study is conducted to measure the atmospheric pressure in a sealed *** experimental sensitivity of the device is 2 Hz/Pa of zirconia and 1.08 Hz/Pa of alumina below 0.5 MPa with a readout distance of 2.5 *** described sensor technology can be applied for monitoring of atmospheric pressure to evaluate important component parameters in harsh environments.

关键词： High temperature co-fired ceramic (HTCC) Wireless Micro-electro-mechanical systems (MEMS)

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An accurate on-demand references broadcast synchronization protocol for wireless sensor network

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Sensors and Transducers 2013年第7期154卷 42-50页

作者： Zhen, Cheng Fang Liu, Wenyi Hou, Yulong Key Laboratory of Instrumentation Science and Dynamic Measurement North University of China Ministry of Education TaiYuan 030051 China National Key Laboratory for Electronic Measurement Technology TaiYuan Shanxi 030051 China

Recent advances in technology have made low cost and low power wireless sensors a reality. Time synchronization may play a key role in wireless sensor networks. In this paper, The AORBS (accurate Ondemand Reference Broadcast Synchronization Protocol) mainly made two improvements on the basis of typical RBS algorithm. Firstly, the node clock is not synchronized with the natural frequency at all time, and the synchronization algorithm will take effect only after an event of interest has happened. Waste is reduced since the system avoids performing synchronization at times when it is not necessary. Furthermore the algorithm achieves the drift compensation by using Taylor expansion but not the linear regression method, greatly reducing the computation cost and improving the synchronization accuracy. As shown in our experimental results: the improved algorithm is more efficient and can be applied to a variety of scopes and types of wireless sensor networks. © International Frequency Sensor Association (IFSA). All rights reserved.

关键词： Wireless sensor networks

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Design and analysis of capacitive micromachined ultrasonic transducers based on SU-8

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key Engineering Materials 2015年 645卷 577-582页

作者： Li, Yuping He, Changde Zhang, Juanting Song, Jinlong Zhang, Wendong Xue, Chenyang Key Laboratory of Instrumentation Science and Dynamic Measurement Ministry of Education North University of China Taiyuan030051 China Key Laboratory of Science and Technology on Electronic Test and Measurement North University of China Taiyuan030051 China

In this paper, a new capacitive micromachined ultrasonic transducer (CMUT) is designed by using SU-8 material, and the theory of elastic thin plate is used to deduce the relationship between the pressure and capacitance of the structure. Simulation has been done about SU-8 CMUT by finite element method software ANSYS. The deformation of CMUT under acoustic pressure, the relationship between frequency, thickness and sensitivity, as well as the acoustic impedance and reflection coefficient of SU-8 material also have been studied through the simulation. The results turn out that SU-8 has the advantages of big dynamic range, high sensitivity and small acoustic impedance, so it has broad application in the ultrasonic field. © (2015) Trans Tech Publications, Switzerland.

关键词： Finite element method

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The analysis and correction of factors influencing imaging quality of digital radiographic testing system

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WSEAS Transactions on Mathematics 2008年第5期7卷 283-292页

作者： Cheng, Yao-Yu Li, Yong-Hong Hu, Yan Liu, Yan-Hua National Key Laboratory for Electronic Measurement Technology North University of China Key Laboratory of Instrumentation Science and Dynamic Measurement No.3 of Institute Road Taiyuan City Shanxi Province 030051 China

The factors influencing imaging quality of industrial digital radiographic imaging system are analyzed detailedly. This imaging system is a new type industrial digital radiographic imaging system developed by author, The structure of ray conversion screen and its non-uniformity, the discordance analysis of scientific grade CCD and vignetting effect of the optical system are introduced. The correction method of non-uniformity for testing system is studied, the correction arithmetic is given and the methods of reducing circuit random noise and the noise produced by scatter ray are illuminated. The correction image and the one that don't be corrected are given, the merits of this system and problem need to be more studied are illuminated.

关键词： Imaging systems

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