Electrocircuit principle’s research of ring space array torque sensor’s reader head

Based on the principle of electromagnetic induction of exchange and the measurement principle of the ring space array torque which is related to the sphere symmetry, the measurement principle of a ring space array torque sensor is discussed which is fit for measuring in extreme environment. The reader head electrocircuit is designed which is combined with the problems on measurement of mechanical torque in extreme environment. The experimentation is emulated and the preferably satisfied result is gained.     

A Method for Online Measurement of Dielectric Loss of HV Capacitive Equipment Insulation

It is still a major problem for research on online monitor dielectric dissipation factor of high voltage equipment insulation. In the field, new methods are paid attention by researchers especially. At present, there are no methods achieving the satisfactory measurement results. Based on the voltage and current at their respective zero crossed points, this paper proposes the integral measurement method which can be used to measure the dielectric dissipation factor of high voltage capacitive apparatus. The formula for dielectric dissipation factor angle computation is deduced by theoretical analysis and the computation results are achieved by digital simulation. Meanwhile, this paper explains the effect to measurements by system frequency, content of harmonic and zero-drift and draws the relevant error curves. It also proposes the measures to reduce the integral measurement method presented in this paper,which can convert measurement of small signal into that of big signal and accurately measure dielectric loss of capacitive apparatus. It also possesses great anti jamming ability under strong electromagnetic interference environment. The online measurement system can detect the dielectric dissipation factor of high voltage equipment by the integral measurement method.     

基于介电法原理的传感器技术在土壤水分监测领域应用探究

伴随着传感器技术的发展,市场上出现了多种类型的土壤水分传感器,其中,基于介电法原理的传感器技术,如时域反射法、时域传输法、频域分解法及驻波比法应用最为广泛。通过对土壤水分传感器性能、结构、测量尺度、安装和应用中的问题及解决方法进行探究,总结目前传感器技术在土壤水分监测中的应用。结果表明：当前土壤水分传感器在性能、结构上存在差异性,在测量尺度上存在不确定性,安装方法上可分为垂直剖面法、阶梯法和单点法,在实际应用中,深层土壤水分及小尺度土壤水分自动监测技术以及传感器统一标定方法有待进一步研究。     

The study on EMI principle and suppression method of vehicle ignition system

Vehicle ignition system is the main electromagnetic interference source. Electromagnetic radiation produced by ignition system will produce the interference to electromagnetic environment around. It is necessary to study the electromagnetic interference (EMI) principle, noise paths and suppression method. We analyze the electromagnetic interference principle of ignition system, and harness trouble-shooting related to electromagnetic interference is also tested. Results show that the spark discharge between spark plug electrodes is the main interference source in ignition system. Then, the paths of conducted interference and the reason of radiated emission are discussed in detail. Finally, two kinds of power supply cord EMI filters are designed and implemented on the basis of analysis results. Experimental results indicate that the filter can reduce the noise of power-wire in broadband range. Simultaneously, the radiation emission performance from power wire is also reduced observably. The proposed mixing filter has been demonstrated in this paper to perform satisfactorily with excellent effectiveness in suppression of conducted EMI from 10 MHz to 110 MHz, and the object car can also pass the EMC standard tests.     

土壤水分快速测量传感器研究及应用进展

土壤水分的测量直接关系到作物的灌溉,进而影响到作物的产量,是一项长期且艰巨的任务。总结了目前市场上3种主流的基于介电原理的土壤水分传感器,阐述了它们的测量原理、标定方法、影响因素以及性能情况,分析了使用过程中可能出现的一些问题,并对其未来的发展方向进行了展望,旨在为农技、水利部门在选用该类型的土壤水分传感器产品和测量土壤水分的过程中提供一定的参考和借鉴。     

Micro Displacement Measurement System

In order to solve the shortcoming of generally used measure method for Micro displacement,which is expensive and unable to automotive longtime watch,a sort of MDMS is gwen based on the corner reflector and microwave phase measurement.In the situation in which the direction of the micro displacement parallels to that of electromagnetic wave radiation,the basic MDMS is recommended.Otherwise the bend MDMS is recommended.The principle of MDMS is described.The example of channel calculation and circuit for transmitting measure result are also provided.The communication circuit transmits measurement to termination demanded.Finally the experiment results are given.     

A Non-linear Circuit Model of A Self Scanned Photodiode Array Image Sensor

A non-linear circuit model of photodiode built according to the working principle of self-scanned photodiode array image sensor is presented for improving the property of the sensor. Through the analysis of the non_linear circuit model,we get the state equations, and the equations are resolved with Runge_Kutta algorithm. The Runge_Kutta algorithm is realized in C language, and the numeric result of the circuit is obtained. The analysis of the numeric result of the model shows that the non_linear performance of the sensor can be improved by reducing the capcitor of the PN junction and the dynamic performance of the image sensor can be enhanced by paralleling capacitor C M , and all the analysis is consistent with the real measurement results of the sensor. The circuit model of photodiode is improved over previous model.     

Nitrogen status and biomass determination of oilseed rape by laser-induced chlorophyll fluorescence

Site-uniform nitrogen fertilization can lead to local over- or under-supply of nitrogen on heterogeneous sites. Suitable sensor solutions are needed to perform on-the-fly measurements of the local N-requirement. Sensor systems already in use to this end in agricultural practice are based on light reflectance measurements.By contrast, a measurement principle based on laser-induced two-wavelength chlorophyll fluorescence (LICF) presents some major advantages given that the measurement signals originate only from plant material. The LICF measurement principle measures the chlorophyll fluorescence induced by red laser light at 630 nm at wavelengths of 690 nm and 730 nm. The ratio of the two wavelengths correlates strongly with aboveground N content, with statistical analysis of measurement data providing biomass information. Thus, both N content and biomass can be determined simultaneously using this technology.This work tested the accuracy of this measurement principle in determining N content and biomass of oilseed rape in field trials. LICF measurements were compared to reflectance-based measurements, both of which were referenced against conventionally determined values for N content and biomass dry weight.Our results show that the N status and aerial biomass dry weight determination by LICF measurements are possible with the same accuracy as with the conventional determination. Furthermore, it could be shown that the LICF measurement allows for the determination of biomass independent of the N content. The good performance of LICF-based protocols in determining local N content and biomass supports their potential utility in site-specific fertilizer application.     

利用光波测控储粮害虫研究进展

光波监测昆虫种群的动态是目前无公害防治害虫方法中的研究热点.综述了不同光波对储粮害虫的监测和防控的研究进展.简单描述光波测控设备的工作原理,总结了近些年光波测控储粮害虫的研究概况,光波测报储粮害虫与传统选筛法之间的对比,以及目前光波测控储粮害虫存在的问题,并就光波测控储粮害虫中的IPM原理进行了简单的阐述以引导广大储粮管理人员正确选择储粮害虫防治方法,真正做到“以防为主,综合防治”,达到绿色储粮的要求.     

应用STM32系统设计基于物联网的农业小气候观测传感器

为实现分布式测量的农业小气候观测系统设计,需要设计一种体积小、成本相对较低的观测传感器。设计中应用STM32系统,采用现代电子设计技术及智能化的软硬件开发,实现传感器的设计制造。结果表明,应用STM32系统进行主控单元硬件设计,及STM32系统自带的标准库函数开发固化软件,不仅功能上能够满足要求,而且设计及生产成本均较低。设计完成的一体式传感器不仅能够更好地满足农业小气候观测需求,而且较集中控制方式的农业小气候观测系统有安装维护上的优势,其体积小,而且“全无线”设计,不会影响农事活动。基于物联网的智能化传感器设计为实现分布式测量打下了基础。     

基于传输线网络的特高压变电站智能组件端口电磁骚扰的建模仿真

随着智能化GIS设备的发展,GIS设备上集成了大量电子设备。GIS设备开关操作产生的特快速瞬态电磁过程主要经由“传感器—二次电缆—智能组件”这段电路对电子设备产生电磁影响。笔者首先基于传输线网络理论建立了开关操作产生的地电位升对“传感器—二次电缆—智能组件”回路的耦合计算模型,然后通过验证实验证明了计算模型的有效性和准确性,最后对不同屏蔽层接地方式下的各传感器端口和智能组件各端口及端口间的骚扰电压进行了仿真研究。计算结果显示,各骚扰电压受接地方式的影响较大;通过选择合适的接地方式,可以有效地抑制开关操作电磁骚扰。     

A Kind of Hardware Realization Method of Solid State Image Sensor Signal Equidistance Subdivision

Basing on the sampling and recovery theorem, this paper investigates the principle of equidistance subdivision for image sensor export signal by hardware circuit.The mechanism of the hardware equidistant subdivision and the function of the image sensor are analyzed, and the circuit diagram of the hardware equidistant subdivision is given with the export signal of the image sensor. Based this, the simulated experiment is a testing of the laser diffraction pattern by electronic CAD PSpice software. This simulated experiment shows that the method with the hardware equidistant subdivision can improve highly its measured accuracy (especially the device of low bit and big central distance), in Laser diffraction measure fine wire diameters, so this experiment can prove its true of the theoretical analysis. This method also eliminates nonuniformity of the device, to large extent, by low pass filter.     

Relativistic Correction of the Static Absolute Position Equation of the GPS

The static absolute position principle of Global Position System(GPS) is analyzed.The more strict equations of the GPS static absolute position are obtained,by considering the effect of the transmission of signal in earth's gravitation,on the condition that the earth's gravitation is static and spherically symmetric.The satellites' mass can be ignored and the satellites move in circular orbits.The effects of the other celestial bodies on the space-time can be neglected.And then the values of the correction quantities is estimated.The correction quantities are very small,about at the orders of magnitude from mm to cm.Moreover,the current GPS's corrections to the satellite clocks are not correspondent theoretically with the theory of measurement of general relativity.     

Optimizing a Diode Array VIS/NIR Spectrometer System to Detect Plant Stress in the Field

Several spectrometer types for the detection of plant stress symptoms by measuring reflectance of crop canopies have been described in the literature. Only a few of them were field‐portable and combine both the visual (VIS) and near‐infrared (NIR) spectral ranges. In particular, NIR spectra enable considerable improvements in assessing crop properties. In the current study, a diode array two‐channel VIS/NIR spectrometer combination was adapted from laboratory to field application and optimized with regard to measuring configuration and procedure. Two plant canopies representing two extremes of morphological differentiation were studied. They consisted of a winter oilseed rape and a grass turf canopy of high vs. low morphological complexity. Derived from grass turf and winter oilseed rape canopy reflectance in the VIS and NIR spectral range vegetation indices (REIP, R₈₅₀ and SRWI) were calculated. It was shown that the choice of sensor head configuration mainly affected sensitivity and accuracy of measurements, whereas the vegetation indices were mainly influenced by sensor‐target angle, sensor‐target distance, daytime of measurement and cloud coverage. However, most impairments were substantially reduced by using a continuous referencation. Best results were obtained using an open fibre optic cable, sensor‐target distance of 1 m in nadir direction and a measurement interval between 12.00 and 16.00 h at clear sky conditions. To show the applicability of the proposed configuration and measurement protocol, growth traits of a winter oilseed rape canopy were investigated at an early stage of development. Based upon vegetation indices, reductions in shoot dry matter, shoot‐N concentration and shoot water concentration were reliably detected. Conclusively, this paper studies the effect of sensor head configuration, sensor‐target angle, sensor‐target distance and daytime of measurement on observed canopy reflectance in the VIS and NIR spectral range. Additionally, it presents, for the first time, a comprehensive and integrated analysis of the way in which these factors affect vegetation indices (REIP, R₈₅₀ and SRWI) derived from VIS and NIR spectra. The optimized procedure reduced interferences, expanded operation time and enabled high‐resolution reflectance measurements in the field.     

Realization for Nonuniformity Correction of Image Sensor Based on the CPLD

Because any type of image sensor has the inevitable question of nonuniformity which directly affect the quality of image and its using range, the paper discusses the principle and algorithm of multi-point nonuniformity correction and designs the scheme of nonuniformity correction based on Complex Programmable Logic Device (CPLD). The CL512J Self Scanned Photodiode Array(SSPA) image sensor is used in the nonuniformity realtime correction experiment. The result of experiment shows the correction system can reduce the nonuniformity of this image sensor from 40% to 2%.     

Directly Electromagnetic Driving of a Self-movable Wall-climbing Micro-robot

The method of directly driving a self-movable wall-climbing micro-robot and utilizing double electromagnetic forces interaction is studied.The principle of monolayer driving fashion, double deck driving fashion and differential driving fashion is analyzed.Three electromagnetic direct driving methods are contrasted by analysis and test, which established the foundation for the research of the self-movable wall-climbing micro-robot.     

Study on Application of Intelligent Material Systems and Structures to Civil Engineering

The fundamental principle and mechanical behavior of several intelligent material systems, such as shape memory alloy, piezoelectricity and fiber optic sensor etc. are discussed in this paper. Some application to civil engineering structures and related research are introduced briefly. The existing problems in the application and research are also presented at the same time. The future development of the intelligent material systems and structures are prospected and some proposals are put forward.     

Capacitance Sensor Displacement Transmission Device Plan for Hydraulic Turbine Leaf of Transmit Water Current Relay Machine

The author analyzes contact and easy wearing and reliability of export signal existing in potentiometer terminal model hydraulic turbine leaf of transmit water current servomotor displacement transmission equipment. A hydraulic turbine leaf of transmit water current relay machine displacement transmission device is designed based on the principles of caoacitance sensor. The device can avoid the problem of old displacement transmission, and long time and reliably measure displacement volume of hydraulic turbine leaf of transmit water current relay machine.     

Application of Sound Intensity Technique to Measure the Noise of Electromotor

This paper has explained the characteristics,virtue of sound intensity measurement and the principle. And compare with traditional sound pressure measurement. The principle and composing of virtual sound intensity measurement system based on two-channel FFT analysis are researched. The sound power of large turbogeneratorin operating site is determined by means of sound intensity measurement and sound pressuremeasurement. Itis demonstrated that the method of sound intensity measurement of engine is practicable and the measuring data are valid and the method conquers the problems of traditional method of sound pressure measurement which is apt to environmentinfluence and sound power measurement need to especially acoustic environment. It is proved that the sound intensity method is especially suited to determine highaccuratelythe sound Power level of the electrical machines operating in situated conditions especially in case of acoustically worst environments or on loadand themethod is so superiorityin noise measurement.     

MATHEMATICAL MODEL OF CAPACITANCE SENSOR FOR MOISTURE MEASUREMENT

This paper presents a theoretical mathematical model of capacitance sensor for moisture measurement. The practical mathematical model is provided using least squares theory, an applied example shows higher accuracy of the model.