scholarly journals Temperature Sequential Data Fusion Algorithm Based on Cluster Hierarchical Sensor Networks

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4533
Author(s):  
Tianwei Yang ◽  
Xinyuan Nan ◽  
Weixu Jin
Keyword(s):  
Temperature Measurement ◽  
Sequential Analysis ◽  
Large Temperature ◽  
Fading Memory ◽  
Local Measurement ◽  
Global State ◽  
Temperature State ◽  
Covariance Intersection ◽  
Pulp Temperature ◽  
State Fusion

The process of extracting gold by biological oxidation involves oxidizing the refractory high-sulfur and high-arsenic ore with the help of bacteria to decompose the wrapping material of gold to extract the gold. Therefore, maximizing the activity of bacteria will directly affect the efficiency of gold extraction, for which it is particularly important to maintain the pulp temperature in the oxidation tank at the optimal bacteria breeding temperature. However, gold mines are generally located in mountainous areas, and the large temperature difference between day and night in winter, coupled with the influence of wind and snow, creates variations in the temperature in the oxidation tank. The traditional temperature measurement method cannot fully reflect the temperature change of the oxidation tank. As a multi-field application method, sensor information fusion can effectively address the problem of pulp temperature measurement. First, we analyzed the heat transfer principle inside the oxidation tank, and designed the cluster hierarchical sensor network according to the spatial position of each oxidation tank and the environmental interference factors. The network structure is divided into three layers; the bottom of the sensor to collect pulp temperature data shows a spiral distribution in the inner wall of the oxidation tank. Each cluster head node sensor is used as an intermediate layer to complete local measurement fusion estimation. Finally, the fusion center is taken as the upper layer to realize the global state fusion estimation. Secondly, in the data processing of the bottom temperature sensor, the traditional unscented Kalman filter (UKF) algorithm is improved and the fading memory matrix is added to improve the identification of nonlinear modeling errors. The sequential observation fusion estimator (SOFE) algorithm is embedded in the measurement update to improve the performance of local measurement fusion. Finally, in the global state fusion estimation, the sequential analysis is combined with the inverse covariance intersection, and the sequential analysis and inverse covariance intersection-global state fusion estimation (SICI-GSFE) algorithm is proposed. Through calculation and simulation, the results show that the external interference can be reduced by combining all the temperature state estimations, and the accuracy of the best global temperature state estimation is improved.

Study on characteristics of schottky temperature detector based on metal/n-ZnO/n-Si structures

2020 ◽  
Vol 12 ◽  
Author(s):  
Fang Wang ◽  
Jingkai Wei ◽  
Caixia Guo ◽  
Tao Ma ◽  
Linqing Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Response ◽  
Large Temperature ◽  
Mems Devices ◽  
Temperature Range ◽  
Response Characteristics ◽  
High Temperature Measurement ◽  
Temperature Detector ◽  
Schottky Structure

Background: At present, the main problems of Micro-Electro-Mechanical Systems (MEMS) temperature detector focus on the narrow range of temperature detection, difficulty of the high temperature measurement. Besides, MEMS devices have different response characteristics for various surrounding temperature in the petrochemical and metallurgy application fields with high-temperature and harsh conditions. To evaluate the performance stability of the hightemperature MEMS devices, the real-time temperature measurement is necessary. Objective: A schottky temperature detector based on the metal/n-ZnO/n-Si structures is designed to measure high temperature (523~873K) for the high-temperature MEMS devices with large temperature range. Method: By using the finite element method (FEM), three different work function metals (Cu, Ni and Pt) contact with the n-ZnO are investigated to realize Schottky. At room temperature (298K) and high temperature (523~873K), the current densities with various bias voltages (J-V) are studied. Results: The simulation results show that the high temperature response power consumption of three schottky detectors of Cu, Ni and Pt decreases successively, which are 1.16 mW, 63.63 μW and 0.14 μW. The response temperature sensitivities of 6.35 μA/K, 0.78 μA/K, and 2.29 nA/K are achieved. Conclusion: The Cu/n-ZnO/n-Si schottky structure could be used as a high temperature detector (523~873K) for the hightemperature MEMS devices. It has a large temperature range (350K) and a high response sensitivity is 6.35 μA/K. Compared with traditional devices, the Cu/n-ZnO/n-Si Schottky structure based temperature detector has a low energy consumption of 1.16 mW, which has potential applications in the high-temperature measurement of the MEMS devices.

The Method of Conductor Resistance Autocompensation in New Two-Wire Thermistor Temperature Measurement

2013 ◽  
Vol 718-720 ◽  
pp. 450-454
Author(s):  
Ning Yang ◽  
Hai Ting Zhu ◽  
Shao Shan Zhong
Keyword(s):  
Temperature Measurement ◽  
Current Source ◽  
Processing System ◽  
Constant Current ◽  
Large Temperature ◽  
Constant Current Source ◽  
Thermistor Temperature ◽  
Important Position ◽  
Temperature Measurement System ◽  
Data Acquisition And Processing

Thermistor has a large temperature range, good stability and resistance to oxidation, which occupies an important position in the low-temperature measurement. This article describes new two-wire thermistor temperature measurement device using the Freescale MC9S12XS128 MCU with sampling capacitance. The device is composed of the MCU with its own A/D, MC9S12XS128 MCU, sampling capacitance, amplifier, boosted circuit, data acquisition and processing system, constant current source, etc. Using constant current source and 16-bit A/D converter designs the temperature measurement circuit, it can eliminate the effect from the conductor resistances in the traditional two-wire resistance temperature measurement system and reduce the measurement error which conductor resistances bring. The method is simple, practical, with high accuracy, strong anti-interference ability and other characteristics.

scholarly journals The Importance of Optical Fibres for Internal Temperature Sensing in Lithium-ion Batteries during Operation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3617
Author(s):  
Markus S. Wahl ◽  
Lena Spitthoff ◽  
Harald I. Muri ◽  
Asanthi Jinasena ◽  
Odne S. Burheim ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Lithium Ion Batteries ◽  
Electromagnetic Interference ◽  
Lithium Ion ◽  
Large Temperature ◽  
Fibre Bragg Grating ◽  
Internal Temperature ◽  
Non Invasive ◽  
Discharge Rates ◽  
Charge Discharge

Lithium-ion batteries (LiBs) are widely used as energy storage systems (ESSs). The biggest challenge they face is retaining intrinsic health under all conditions, and understanding internal thermal behaviour is crucial to this. The key concern is the potentially large temperature differences at high charge/discharge rates. Excess heat created during charge/discharge will accelerate irreversible aging, eventually leading to failure. As a consequence, it is important to keep battery states within their safe operating range, which is determined by voltage, temperature, and current windows. Due to the chemically aggressive and electrically noisy environment, internal temperature measurement is difficult. As a result, non-invasive sensors must be physically stable, electromagnetic interference-resistant, and chemically inert. These characteristics are provided by fibre Bragg grating (FBG) sensors, which are also multiplexable. This review article discusses the thermal problems that arise during LiB use, as well as their significance in terms of LiB durability and protection. FBG-based sensors are described as a technology, with emphasis on their importance for direct temperature measurement within the LiB cell.

scholarly journals Experimental Study of Large-Temperature-Range and Long-Period Monitoring for LNG Marine Auxiliary Based on Fiber Bragg Grating Temperature Measurement

2021 ◽  
Vol 9 (9) ◽  
pp. 917
Author(s):  
Fenghui Han ◽  
Zhe Wang ◽  
Hefu Zhang ◽  
Dongxing Wang ◽  
Wenhua Li ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Fiber Bragg Grating ◽  
Optical Fibers ◽  
Storage Tank ◽  
Temperature Sensors ◽  
Large Temperature ◽  
Cryogenic Storage ◽  
Temperature Range ◽  
Long Period

Temperature is a key variable to evaluate the energy consumption and thermodynamic performance of traditional marine auxiliary machinery, chillers and piping systems. In particular, for the cryogenic storage tanks and fuel gas supply systems of LNG ships, explosion-proof and low-temperature-resistance properties bring new challenges to the onboard temperature measurement and monitoring. In order to promote the development of high-performance and safer monitoring systems for LNG ships, this paper adopted fiber Bragg grating (FBG) technology to ensure the measurement safety and accuracy of temperature sensors, and performs a series of experiments in a large temperature range on the chiller, pipeline, and cryogenic storage tank of an LNG ship and their long-term reliabilities. Firstly, the principle and composition of the designed FBG temperature sensors are introduced in detail, and the measurement accuracy and range of different metal-coated optical fibers were tested in a large temperature range and compared against the traditional thermistors. Then, the effects of different operating conditions of the LNG marine chiller system and cryogenic storage tank on the temperature measurements were investigated. In addition, the drift degrees of the optical fibers and industrial thermistors were analyzed to figure out their reliabilities for long-term temperature measurements. The results showed that for the long-period (16 months) monitoring of LNG ships in a large temperature range (105–315 K) under different shipping conditions, the optical temperature measurement based on FBG technology has sufficient accuracy and dynamic sensitivity with a higher safety than the traditional thermoelectric measurement. Besides, the ship vibration, ambient humidity, and great temperature changes have little impact on its measurement reliability and drifts. This research can provide references and technical supports to the performance testing systems of LNG ships and other relevant vessels with stricter safety standards.

Initialization of an ENSO Forecast System Using a Parallelized Ensemble Filter

2005 ◽  
Vol 133 (11) ◽  
pp. 3176-3201 ◽  
Author(s):  
S. Zhang ◽  
M. J. Harrison ◽  
A. T. Wittenberg ◽  
A. Rosati ◽  
J. L. Anderson ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Hybrid Model ◽  
Sequential Analysis ◽  
Surface Wind ◽  
Ocean Model ◽  
Consistent Estimate ◽  
State Variables ◽  
Test Bed ◽  
Background Error ◽  
Temperature State

Abstract As a first step toward coupled ocean–atmosphere data assimilation, a parallelized ensemble filter is implemented in a new stochastic hybrid coupled model. The model consists of a global version of the GFDL Modular Ocean Model Version 4 (MOM4), coupled to a statistical atmosphere based on a regression of National Centers for Environmental Prediction (NCEP) reanalysis surface wind stress, heat, and water flux anomalies onto analyzed tropical Pacific SST anomalies from 1979 to 2002. The residual part of the NCEP fluxes not captured by the regression is then treated as stochastic forcing, with different ensemble members feeling the residual fluxes from different years. The model provides a convenient test bed for coupled data assimilation, as well as a prototype for representing uncertainties in the surface forcing. A parallel ensemble adjustment Kalman filter (EAKF) has been designed and implemented in the hybrid model, using a local least squares framework. Comparison experiments demonstrate that the massively parallel processing EAKF (MPPEAKF) produces assimilation results with essentially the same quality as a global sequential analysis. Observed subsurface temperature profiles from expendable bathythermographs (XBTs), Tropical Atmosphere Ocean (TAO) buoys, and Argo floats, along with analyzed SSTs from NCEP, are assimilated into the hybrid model over 1980–2002 using the MPPEAKF. The filtered ensemble of SSTs, ocean heat contents, and thermal structures converge well to the observations, in spite of the imposed stochastic forcings. Several facets of the EAKF algorithm used here have been designed to facilitate comparison to a traditional three-dimensional variational data assimilation (3DVAR) algorithm, for instance, the use of a univariate filter in which observations of temperature only directly impact temperature state variables. Despite these choices that may limit the power of the EAKF, the MPPEAKF solution appears to improve upon an earlier 3DVAR solution, producing a smoother, more physically reasonable analysis that better fits the observational data and produces, to some degree, a self-consistent estimate of analysis uncertainties. Hybrid model ENSO forecasts initialized from the MPPEAKF ensemble mean also appear to outperform those initialized from the 3DVAR analysis. This improvement stems from the EAKF’s utilization of anisotropic background error covariances that may vary in time.

Thermal State of an Aircraft Aerofoil in a High-Velocity Air Flow

2021 ◽  
pp. 4-24
Author(s):  
Az.A. Aliev ◽  
A.S. Burkov ◽  
V.A. Tovstonog ◽  
V.I. Tomak ◽  
D.A. Yagodnikov
Keyword(s):  
High Velocity ◽  
Zirconium Oxide ◽  
Air Flow ◽  
Temperature Gradients ◽  
Supersonic Combustion ◽  
Design Solution ◽  
Large Temperature ◽  
Aerodynamic Heating ◽  
Correct Operation ◽  
Temperature State

One of the features of high-velocity atmospheric aircraft is the presence of thin aerofoils with edges characterised by a small blunt radius, subjected to high-temperature aerodynamic heating at temperatures of up to 2000 -- 2500 °C. In order to ensure correct operation of both the power plant producing thrust in such vehicles, assumed to be a supersonic combustion ramjet, and respective aerodynamic controls, the components subjected to high-velocity air flows must retain their geometric stability. A way to ensure their performance is to use methods and means of thermal protection, as well as materials that are resistant to high temperatures in an oxidising atmosphere, while one of the promising trends is employing refractory oxide materials such as oxides of aluminium, zirconium and hafnium. Since this class of materials has low thermal conductivity, large temperature gradients develop in the vicinity of the surface being heated, resulting in temperature stresses, all of which designers should take into account. We analysed the temperature state in a model of an acute zirconium oxide wedge featuring a small blunt radius, subjected to a high-velocity air flow. To reduce the edge temperature and temperature gradients, we propose a design solution implemented as a thermally conductive core lined with a thin layer of zirconium oxide. We consider using aluminium oxide and hafnium boride as core materials

Development of a High-Precision Temperature Measurement Instrument Based on Quartz Tuning-Fork Temperature Sensor

2008 ◽  
Vol 381-382 ◽  
pp. 477-480 ◽  
Author(s):  
Jun Xu ◽  
Bo You ◽  
X. Li
Keyword(s):  
Temperature Measurement ◽  
High Precision ◽  
Temperature Sensor ◽  
Tuning Fork ◽  
Measurement Instrument ◽  
Quartz Tuning Fork ◽  
Large Temperature ◽  
Correction Technique ◽  
Marquardt Algorithm ◽  
Precision Temperature

This paper presents a high precision temperature measurement instrument based on quartz tuning-fork temperature sensor (QTTS) using Artificial Neural Networks (ANN). The advantage of QTTS is a great sensitivity which makes possible to determine the temperature with the accuracy of 0.01 °C , but the QTTS based temperature measurement instrument often appears as erroneous temperature reading when using standard polynomial calibration techniques over a large temperature range. For high precision temperature measurement, a new method is presented to compensate non-linearity of QTTS based instrument using non-linearity compensation model using ANN by Levenberg-Marquardt algorithm to settle its non-linear problem. The hardware and software parts of the system are integrated in a PC-based instrument used for operation and calibration. ANN based modelling and correction technique has been evaluated experimentally, followed by experimental results obtained by applying the method to QTTS calibration.

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