Showing papers in "Journal of Transducer Technology in 2005"

Dynamic power management in wireless sensor network

Abstract: An effective method of dynamic power management,based on wavelet and Kalman analysis,is proposed to extend life of wireless sensor network by making economical use of energy.Wavelet,Kalman filter and AR are used to forecast the time when next event will happen,and the state in which wireless sensor should lie is decided based on the time.Total energy consumption is decreased under fraction of event missed as low as posible.Experimental results show the method is effective.

Safety detection of braking system based on wavelet packet and neural network

Abstract: According to the nonstationary fault signal of piston's blockage in hydraulic pressure and electromagnetic driving braking system,a system of extracting feature vectors by the energy of wavelet packet over the signals and imaging the nonlinear transfer characteristics by neural network to realize the safety detection of the machine is presented.The experimental results prove this method is effectual and applied.

Multi-sensor data fusion technique and its application

Abstract: Multi-sensor data fusion is a new technique developed in recent years.Multi-sensor data fusion has attracted a wide spread attention,its theory and methods have been applied to a lot of research fields.The basic concept of multi-sensor data fusion is introduced,and fusion principle,characteristic and architecture,data fusion methods and the scope of applications are discussed.The main problems and development trend are presented.

Design of capacitance micro-displacement sensor and its application

Abstract: The principle of the robot system based on error compensation is presented.The micro-displacement capacitance sensor and its signal conditioning circuit are designed by adopting equipotential annulus technology and driving cable technology.Experimental results show that the sensor's non linearity of 0.2 % and resolution of(0.1 μm) can be achieved.The deviation of the robot system is tested and compensated using capacitance sensor,and the performance of the robot is improved.

Study on pressure sensor based on photonic crystal

Abstract: A new pressure sensor of photonic crystal is introduced,it can convert transverse stress into the changes of band gap of photonic crystal,the pressure on the one-dimension photonic crystal can be measured by detecting the wavelength changes in transmission light.The results show that the measuring range and sensitivity of the sensor is relation to the materials which construct it.The sensitivity is high when the elastic modulus is small,and the measuring range is small when the difference of elastic modulus and Poisson's ratio between the two materials is high.The pressure sensor is small and light.

Application of complex north-finding method in auto-gyroscope system

Abstract: The disfigurement of gyroscope made in our country is described.The optics system construction and working principle of north-finding gyroscope system base on CCD and microprocessor technology are described.The formula of complex method of gyroscope direction and the math models of the complex method in the environment of microprocessor are given.It is proved to be effective through experimentation.The conclusions show that the system can shorten the measuring time,simplify the operation,and improve the north-finding accuracy of gyroscope.The criterion error can be controlled in the circle of 10″.

Design of temperature and humidity wireless monitoring system

Abstract: The operation principle,the design of hardware structure and the experiment results of a temperature and humidity wireless monitoring system are introducedTemperature and humidity sensor is the core of the deviceThe scan control system is constituted by using the transceiver06 ℃ temperature tolerance and 5 %RH humidity tolerance can be measuredThis system has the advantages of small size,low power consumption,simple circuit,convenient installation and monitoring at any time

Modeling and simulation analysis of eddy current sensor

Abstract: A type of waterproof electronic digital calipers is devised using eddy current displacement sensorA 3 D electromagnetism model of the hollow planar windings is simulated and analized with finite element analysis software ANSYSThe mathematic model of the eddy current sensor featuring a hollow planar winding is establishedThe winding is disassembled to multple conductors,which are simulated respectively and indepedently,and combined finallyIn the end, the model is tested to show simulation result is in good agreement with the nature of actual sensorThe result will provide useful analysis method for eddy current sensor to be applied practically

Single sensor data fusion and analysis of effectiveness

Abstract: A mistake of the single sensor data fusion is analyzed. The following conclusion is proved theoretically further. In the system of the single sensor,when observed values of sample are given,the method of data fusion to divide into groups is superior to the estimation result of single group’s arithmetic average. Actual data analysis shows the correction of the conclusion.

Optical voltage transformer based on longitudinal Pockels effects

Abstract: A comparison is made between transverse Pockels effects and longitudinal Pockels effects.The critical technologies to design optical voltage transformer adopting longitudinal Pockels effects are analyzed.Experiments are done using a longitudinal Pockels device with double optical light output,and the test results show that its accuracy is better than 0.2% within the range of 200~600V.If cooperated with accurate capacitive voltage divider,it can be used as the high-voltage transformer.

Study on signal analysis for weigh-in-motion of two-axle vehicle

Abstract: The weight distribution to every axis of vehicle that is in motion is decided by many factors,such as hanging weight,friction in braking system and acceleration.The acquired signal includes the vibration of the vehicle and bedplate.The weight distribution is analyzed when the vehicle passes across the bedplate in non-even speed.First,the velocity and acceleration values are achieved from the dynamic weight signals.Then,the interference parts caused mainly by vibration are eliminated by the method of empirical mode decomposition(EMD) in which the mean value of residue is regarded as real axis weight.The model of the vehicle,velocity and acceleration are used to correct the data dynamically.The conclusion shows that higher precision of measurement can be achieved as long as the vehicle passes across the bedplate in longer time than the base cycle of vibration.

Development status of fiber-optic gyroscopes

Abstract: The fiber-optic gyroscope(FOG) is classified into different types according to its principle and characteristic.The international status of FOG is introduced and the short-term and long-term trend of FOG is forecast.It will be benefit to the course of our FOG.

Error source and elimination of inductosyn azimuth angular measurement system

Abstract: In order to measure azimuth angle precisely,the inductosyn angular measurement system is designed and implemented.According to the working principle of the rotary inductosyn and AD2S80A resolver-to-digital converter,the error source of the system is mainly analysed and proper software and hardware measures are also introduced.The system has compact configuration,strong anti-jamming ability and high precision which reaches 8″.It can measure in the whole circle and its result is displayed digitally,which is straight and convenient to read.The whole system can work reliably in the atrocious circumstances and finely satisfy practical requirements.

Weak signal detection based on chaotic theory

Abstract: The chaotic characteristic of intermittent chaotic model——Duffing oscillator is analyzed,the nonequilibrium phase change of oscillator is sensitive to small signal and immune against white noise and the periodic interfering signal having larger angular frequency difference to the referential signalThe chaotic oscillator array is applied to detect weak signal in noise background,and Melnikov method is adopted as chaotic criterion which is easy to be directly calculatedThe simulation results indicate this detection method is simple and effectiveDetection precision is high

Design of gap determination system for high-speed maglev train

Abstract: A method of gap determination for high-speed maglev train driven by long-stator synchronous linear motor,based on tridimensional coil,is presentedIn which method,reliable gap determination is given with lesser effect of tooth-groove and electronmagnetic interferenceWith this method,the principles,hardware structure and signal processing of an experimental system based on inductance sensor and FPGA are elucidatedExperiment shows that the system has the features of hard real time and high measuring precision,which meets the requirement of the operating control system of high-speed maglev train

Recognition of target using Bayesian data fusion method

Abstract: Principles,fusion model of Bayesian are described,and calculation of a example of target types and attribute is put forward.Using recognition of target of Bayesian probability of target of twice fusion is calculated.The results show that the probability of target recognition is improved and the probability of uncertainty is debased,it is a effective method for target recognition.

Dynamic demodulation technology of fiber grating with high resolution based on cantilever beam

Abstract: A novel approach for testing and demodulation of fiber grating sensors is proposed based on cantilever beam.During the operation of outside acceleration on the cantilever beam,one fiber grating sensor is pressed,while the other is pulled,which doubles the sensitity of wavelength tuning, and this method associates demodulation with temperature compensation,and experimentally proves its advangtage.The measurement accuracy can reach (0.01pm) and acceleration with high resolution can be measured.

Design of hot resistance mode flow velocity instrument

Abstract: The constitution and the hot balance theory of the flow velocity instrument are recommended in here and applied in the water area combining with the factThe system adopts constant temperature and constant current control method and can measure average-time flow velocity of the waterMeasuring range is 0~2m/sAccuracy can reach 1% when low flow velocity is 0~05m/s;accuracy can reach 3% when high flow velocity is 05~ 2m/s

Nerve agent gas sensor based on nano-zeolite films

Abstract: First using ZSM-5 zeolite films to detect the nerve agent similant Dimethylmethylphosphonate,which is regarded as the simulant for sarin.By combining the high sensitivity of QCM,the gas sensor is developed,and the gas volume fractions of 10~(-6),5×10~(-6),20×10~(-6) gases are detected.The result shows the sensitivity to 10~(-6) DMMP is 60Hz,which is lower than EC_(50) (The value of volume fraction times the time,which causes half of the people dead).The velocities of the absorption and desorption are very quick.The response time of absorption and desorption is 100s respectively.The selectivity is also tested with other gases such as acetone at the same volume fraction.The renewablecondition of the ZSM-5 films is also discussed.It is shown that at the desorption temperature of 200℃,the zeolite is thermally stable and shows reproducible response during DMMP gas detection.

Application of eddy current sensor in measuring thickness of aluminum

Abstract: Transmissive eddy current sensor inspired by two sine signals with different frequencies is used to measure the thickness of aluminum foil and the temperature of the surface of aluminum foil on line.And multi-parameter measurement is realized.In order to reduce the no-linear error and cross-sensitivity,immunity algorithm is used to fulfill multi-parameter data fitting.Measurement results show that this kind of data fitting method eliminates the effect of the temperature of the surface of aluminum foil on the measurement of the thickness of aluminum foil,and the measurement precision is increased.The measuring range can reach 1~100μm,the resolution 0.01μm.

Technologies of MEMS packaging

Abstract: The technologies of MEMS packaging are introduced,including three promising technologies:wafer level packaging,single-chip packaging and multi-chip packaging,modular MEMS packaging and flip-chip bonding for MEMS packaging.Then several reliability issues in MEMS packaging are pointed out,and a forecast is given for its future trends.

Study on differential transformer displacement sensors for active magnetic bearings

Abstract: The differential transformer displacement sensor applying in active magnetic bearings is designedBased on the principle and characteristic of active magnetic bearing,the improved project in structure for the sensor is presentedThe linear variable differential transformer (LVDT) signal conditioner AD598 is used as measuring circuit for the sensorThe experiment concludes that the designed sensor has preferable performance:the linearity is±125% and sensitivity is 2377mV/μm in the measuring range of -035~035mmIt is suitable to active magnetic bearing

Application of LM algorithm in data fusion disposal of sensor

Abstract: LM algorithm is adopted to solve the problem of intercross sensitivity of pressure sensor to temperature and to perform data fusion disposal.The method eliminates the influence of the temperature on pressure sensor and improves the stability and accuracy of the sensor.The effect is proved to be fairly well.Considering the measurement error of the sensor,a noise can be added to train the network to improve its fault tolerance.Emulation research and simple analysis are taken in this method,and through comparing whit non linear interpolation algorithm (3 order polynomial interpolation),some mechanisms when implementing neural network in data fusion are pointed out.

Synchronous control research of TDI-CCD camera dynamic imaging

Abstract: First of all,the structure and principle of time delay integration charge coupled devices(TDI-CCD) image sensor have been introduced.Second,with the help of the modulated transfer function(MTF),the negative effect on image quality is fully analyzed,which is caused by the mismatch between TDI-CCD line scanning and velocity of image motion.Theoretic analysis and experiment simulation show that the negative effect can be reduced greatly only that mismatch error band is strictly controlled in the scope of Nyquist frequency during process of imaging.Finally,two practicable and simple synchronous control ways are presented.

Study of modeling and simulation of magnetic modulator

Abstract: Simulation model of magnetic modulation comparator based on SIMULINK environment of MATLAB is built up.The model can exactly simulate the saturation of B-H curve of permalloy core,and overcome the shortage of traditional charting method.It takes into account the influence of the self-resistance of stimulation winding, direct winding and measurement winding.The presented method can give great help to know the operating mechanism of magnetic modulation comparator, which also is important to design the comparator with satisfactory performance.

Portable intelligent instrument for pumping data collection

Abstract: An instrument for pumping data collection based on single chip microcomputer is introduced.It is used for its convenience and flexibility.The function,the desigin of hardware and solftware are indroduced too.Practical application shows that this system has strong anti-interference ability,stable performance.

Soft-measurement technique and applications based on support vector machine

Abstract: The support vector machine (SVM) is an algorithm based on structure risk minimizing principle and high generalization ability.The soft-sensing technique based on least squares-support vector machine(LS-SVM) is presented,and it has been successfully applied to the soft- measurement of NO_X from bus.The result shows that the method based on LS-SVM has obvious advantages than neural network method.Moreover,LS-SVM offers a kind of effective way for soft-sensing model of small sample space,non-linearity,high dimensions.

New type of P~+-I-N~+ double injection magneto-sensitive difference circuit developted on SOI

Abstract: New type of P~+-I-N~+ double injection magneto-sensitive difference circuit is based on SOI,its design principle and process are expatiated,and the recombination region of the magneto-transistor is set up by anisotropic etching technology in MEMS.At the same time,the recombination mechanism of the recombination region is given.The result of experiment shows that this kind of transistor is provided with high magnetic sensitivity,low noise and high reliability.So,the difference circuit consisted of this transistor has merit of small temperature shift.

Research advance in explosive detection by electronic nose

Abstract: There are many kinds of electronic nose(EN).IMS,amplifying chromophore quenching,fiber-optic sensor,MIME-type chemical sensor,polymer thin film,SAW sensor,MEMS are described.Different performances of detectors with different principles in explosives detection are introduced.

Data analysis and modeling research of MEMS gyroscope drift

Abstract: The random error of a MEMS gyro is tested and studied.A state space model is picked out for modeling of the gyro drift.The subspace stochastic system identification method is employed to generate the model.The result is consistent with the random error characteristic obtained from Allan variance method.Compared with the ARMA model, the model is lower at similar performance.And it is more suitable for optimal online estimator.The presented method can be directly extended for multi-axes gyros.