Temperature Compensation Method Research Articles

Research on reflective intensity-modulated fibre optical pressure sensor based on desensitisation of temperature compensation method

Research on reflective intensity-modulated fibre optical pressure sensor based on desensitisation of temperature compensation method

RGBW LED mixing temperature compensation method with high output consistency

This paper proposes a temperature compensation method for RGBW LED mixing based on fast non-dominated sorting genetic algorithm(NSGA-II). The proposed method can achieve compensation for temperature-induced changes in LED correlated color temperature (CCT), color fidelity (Rf) and color gamut index (Rg) by predicting the spectral power distribution (SPD) at different temperatures. The SPD-temperature model of the RGBW LED light source is established by measuring the spectral power distribution of LEDs at different temperatures. Based on the established model, NSGA-II is used to compensate the mixing temperature of the RGBW LED light source according to the spectral superposition theorem. The experimental results show that the fit of the established temperature-spectral model is R2 > 0.98, and the deviation of the compensated mixing results from the initial state of the light source is less than 10 K in CCT; the deviation value of Rf is less than 4 % in the range of 2000 K-7000 K, and less than 2.15 % in the range of 3000 K-7000 K; and the deviation value of Rg in the range of 2000 K-7000 K is less than 4.46 %.

Research on temperature compensation method for photoelectric sensors

In order to make the temperature error of fiber-optic current sensor (FGB) based on polarization modulation principle meet the requirements of engineering applications, the temperature error characteristics of FGB are analyzed theoretically, and the optimized BP neural network is used for the temperature compensation of FGB, which realizes the nonlinear temperature error correction of the sensor, and compares and analyzes the experimental results with those of other types of temperature compensation algorithms. The results show that the temperature compensation results based on the neural network algorithm are better than other compensation effects. Finally, the repeatability of the FGB was experimentally verified using its full temperature experiment, and the temperature errors of the FGB in the range of 20 ℃~ 100 ℃ were less than 0.5% after the correction of the neural network algorithm.

Determination of difluoromethane (R32) by non-dispersive infrared (NDIR) spectroscopy with temperature compensation by an improved whale optimization algorithm (IWOA)

To reduce the influence of temperature on difluoromethane (R32) gas sensors using non-dispersive infrared (NDIR), a temperature compensation method based on improved whale optimization algorithm (IWOA) and back propagation neural network (BPNN) is proposed. The IWOA that uses tent chaotic mapping to optimize the initial population of the whale optimization algorithm (WOA) and incorporates adaptive weights in the population iterations is used to optimize the weights and thresholds between nodes in each layer of the BPNN. The optimized BPNN is used to train the temperature compensation model. The experimental results show that the back propagation neural network optimized with improved whale optimization algorithm (IWOA-BPNN) reduces the maximum relative error to 1.33%, compared to 12.46 and 11.66% for the traditional BPNN and the back propagation neural network optimized with whale optimization algorithm (WOA-BPNN), respectively. IWOA-BPNN is also compared with previously reported algorithms, and the results show that the algorithm improves the accuracy of the sensor.

FBG-based three-dimensional micro-force sensor with axial force sensitivity-enhancing and temperature compensation for micro-forceps.

During retinal microsurgery, excessive interaction force between surgical instruments and intraocular tissue can cause serious accidents such as tissue injury, irreversible retinal damage, and even vision loss. It is essential to accurately sense the micro tool-tissue interaction force, especially for the Ophthalmic Microsurgery Robot. In this study, a fiber Bragg grating (FBG) three-dimensional (3-D) micro-force sensor for micro-forceps is proposed, which is integrated with the drive module as an end-effector and can be conveniently mounted onto the ophthalmic surgical robot. An innovative axial force sensitivity-enhancing structure is proposed based on the principles of flexure-hinge and flexible levers to overcome the low sensitivity of axial force measurement. A dual-grating temperature compensation method is adopted for axial force measurement, which considers the differential temperature sensitivity of the two FBGs. Three FBGs are arranged along the circumference of the guide tube in this study to measure transverse forces and compensate for effects caused by changes in temperature. The experimental results demonstrate that the micro-forceps designed in this study achieved a resolution of 0.13 mN for transverse force and 0.30 mN for axial force. The temperature compensation experiments show that the 3-D micro-force sensor can simultaneously compensate for temperature effects in axial and transverse force measurement.

The temperature effects on embedded PZT signals in structural health monitoring for composite structures with different thicknesses

Ultrasonics guided waves (GWs) are established as an effective structural health monitoring technique for detecting damage in composite structures. However, for GWs to be applied reliably in service, the effect of temperature needs to be accounted for baseline damage detection approaches. Previous studies have focused on developing temperature compensation methods for surface-mounted transducers. In this paper, an extensive investigation has been carried out to develop an effective temperature compensation method for GWs generated by embedded transducers in different thickness composites. To accomplish this, Laser Doppler Vibrometer experiments were carried out to obtain wavenumbers generated by embedded transducers and to compare them against surface mounted cases. The consistent trend observation of dispersion curves between surface-mounted and embedded PZTs serves as a foundation for conducting analysis of the embedded signals with the effect of temperature. Following that, GW propagation has been studied in three quasi-isotropic composites of 2 mm, 4 mm and 9 mm thicknesses. Based on the established temperature database with measurements from − 50 °C to 70 °C, a temperature compensation methodology has been developed and validated with the temperature difference of 30 °C. It demonstrates that the temperature effect on the embedded PZTs is lower in comparison to surface mounted PZTs, and the temperature compensation of a single thickness composite is scalable to other panels thickness. This novel methodology proves beneficial in reducing the scale of the experimental campaign required, which holds significant value for actual aeronautical structures characterized by variable composite thicknesses across different sections, such as in fuselage panels or wing boxes.

A Novel Temperature Compensation Method for Surface Strain of Cylindrical Lithium-ion Batteries

In order to ensure the safe operation of lithium-ion batteries, real-time monitoring of battery status is necessary. The surface strain signal of lithium-ion batteries has the potential to evaluate the battery’s state, but it is significantly affected by temperature. Generally, measuring the battery surface temperature and the thermal expansion coefficient can be performed to quantify and eliminate the influence of temperature on strain, but this increases the cost and complexity of strain measurement. This article proposes a method that eliminates the need to measure the battery temperature and material parameters. By simultaneously measuring the circumferential and axial strains on the battery surface and calculating their difference, the influence of temperature on strain can be minimized. Furthermore, the effectiveness of the proposed method is experimentally tested. Results demonstrate that after applying temperature compensation to commercial lithium-ion batteries, the influence of temperature on strain can be reduced from 16.4 ppm/°C to 1.7 ppm/°C. The strain no longer exhibits sensitivity to current, making it more suitable for evaluating the state of lithium-ion batteries.

High reliability damage imaging under non-uniform environmental temperature variations based on modified dynamic time warping

In practical applications of Lamb wave monitoring, the environmental temperature fields usually vary non-uniformly over the monitored structures, which can inconsistently affect the wavepackets of every diagnostic signal and reduce the reliability of final detection results. A number of temperature compensation methods have been reported. However, under the complicated non-uniform temperature variations, many methods are deteriorated in their performance or require large amount of Lamb wave data. To effectively improve the reliability of Lamb wave damage detection under non-uniform temperature variations, modified dynamic time warping (MDTW) is presented in this paper. In MDTW, with the flexible time alignment ability of dynamic time warping (DTW), the non-uniform temperature variation effects on Lamb wave signals can be compensated just requiring one set of baselines. Furthermore, to preserve the damage information in the compensated signals, the warping adjusting mechanism is introduced to resolve the temperature over-compensation problem of traditional DTW. This makes MDTW a robust non-uniform temperature compensation method for high reliability Lamb wave detection. After the basic principle of DTW is analyzed, MDTW is proposed and numerically validated. Then, a MDTW-based Lamb wave imaging method is developed for high reliability damage imaging, in which a triple-suppression of non-uniform temperature variations can be accomplished. Finally, the efficiency of MDTW and MDTW-based imaging is demonstrated by the temperature experiment of A0 mode Lamb wave damage imaging on an aluminum plate with its temperature field non-uniformly varied by 13℃∼43℃.

A Novel Catheter Shape-Sensing Method Based on Deep Learning with a Multi-Core Optical Fiber.

In this paper, we propose a novel shape-sensing method based on deep learning with a multi-core optical fiber for the accurate shape-sensing of catheters and guidewires. Firstly, we designed a catheter with embedded multi-core fiber containing three sensing outer cores and one temperature compensation middle core. Then, we analyzed the relationship between the central wavelength shift, the curvature of the multi-core Fiber Bragg Grating (FBG), and temperature compensation methods to establish a Particle Swarm Optimization (PSO) BP neural network-based catheter shape sensing method. Finally, experiments were conducted in both constant and variable temperature environments to validate the method. The average and maximum distance errors of the PSO-BP neural network were 0.57 and 1.33 mm, respectively, under constant temperature conditions, and 0.36 and 0.96 mm, respectively, under variable temperature conditions. This well-sensed catheter shape demonstrates the effectiveness of the shape-sensing method proposed in this paper and its potential applications in real surgical catheters and guidewire.

Temperature Compensation of Wind Tunnel Balance Signal Detection System Based on IGWO-ELM.

The wind tunnel balance signal detection system is widely employed in aerospace applications for the accurate and automated measurement of aerodynamic forces and moments. However, measurement errors arise under different environmental temperature. This paper addresses the issue of measurement accuracy under different temperature conditions by proposing a temperature compensation method based on an improved gray wolf optimization (IGWO) algorithm and optimized extreme learning machine (ELM). The IGWO algorithm is enhanced by improving the initial population position, convergence factor, and iteration weights of the gray wolf optimization algorithm. Subsequently, the IGWO algorithm is employed to determine the optimal network parameters for the ELM. The calibration decoupling experiment and high-low temperature experiment are designed and carried out. On this basis, ELM, GWO-ELM, PSO-ELM, GWO-RBFNN and IGWO-ELM are used for temperature compensation experiments. The experimental results show that IGWO-ELM has a good temperature compensation effect, reducing the measurement error from 20%FS to within 0.04%FS. Consequently, the accuracy and stability of the wind tunnel balance signal detection system under different temperature environments are enhanced.

Combined Temperature Compensation Method for Closed-Loop Microelectromechanical System Capacitive Accelerometer.

This article describes a closed-loop detection MEMS accelerometer for acceleration measurement. This paper analyzes the working principle of MEMS accelerometers in detail and explains the relationship between the accelerometer zero bias, scale factor and voltage reference. Therefore, a combined compensation method is designed via reference voltage source compensation and terminal temperature compensation of the accelerometer, which comprehensively improves the performance over a wide temperature range of the accelerometer. The experiment results show that the initial range is reduced from 3679 ppm to 221 ppm with reference voltage source compensation, zero-bias stability of the accelerometer over temperature is increased by 14.3% on average and the scale factor stability over temperature is increased by 88.2% on average. After combined compensation, one accelerometer zero-bias stability over temperature was reduced to 40 μg and the scale factor stability over temperature was reduced to 16 ppm, the average value of the zero-bias stability over temperature was reduced from 1764 μg to 36 μg, the average value of the scale factor stability over temperature was reduced from 2270 ppm to 25 ppm, the average stability of the zero bias was increased by 97.96% and the average stability of the scale factor was increased by 98.90%.

Development of a gas chromatography system coupled to a metal-oxide semiconductor (MOS) sensor, with compensation of the temperature effects on the column for the measurement of ethene

Abstract. A possible way to reduce the size and complexity of common gas chromatography (GC) systems is the economization of the column temperature regulation system. To this end, a temperature compensation method was developed and validated on a benchtop GC-PDD (pulsed discharge detector) with ethene. An in-house-developed algorithm correlates the retention index of a test gas to the retention index of a previously selected reference gas. To investigate further methods of cost reduction, commercial gas sensors were tested as cheap, sensitive, and versatile detectors. Therefore, CO2 was chosen as a naturally occurring reference gas, while ethene was chosen as a maturity marker for climacteric fruits and hence as a test gas. A demonstrator, consisting of a simple syringe injection system, a PLOT (porous layer open tubular) column boxed in a polystyrene-foam housing, a commercial MOS (metal-oxide semiconductor) sensor for the test gas, and a CO2-specific IR (infrared) sensor, was used to set up a simple GC system and to apply this method on test measurements. Sorption parameters for ethene and CO2 were determined via a van 't Hoff plot, where the entropy S was −11.982 J mol−1 K−1 ΔSEthene0 and 1.351 J mol−1 K−1 ΔSCarbondioxide0, and the enthalpy H was −20.622 kJ mol−1 ΔHEthene0 and −14.792 kJ mol−1 ΔHCarbondioxide0, respectively. Ethene (100 ppm) measurements revealed a system-specific correction term of 0.652 min. Further measurements of ethene and interfering gases revealed a mean retention time for ethene of 3.093 min; the mean predicted retention time is 3.099 min. The demonstrator was able to identify the test gas, ethene, as a function of the reference gas, CO2, in a first approach, without a column heating system and in a gas mixture by applying a temperature compensation algorithm and a system-specific holdup time correction term.

Design of MEMS gyroscope interface ASIC with on-chip temperature compensation

Zero bias and scale factor are important overall performance indicators for micromechanical gyroscopes and are commonly used to describe the temperature stability of MEMS gyroscope. This article presents a mode-matched MEMS gyroscope interface Application Specific Integrated Circuit (ASIC) with on-chip temperature compensation, which improves the temperature adaptability of the gyroscope by means of temperature compensation. By establishing a mathematical model between the equivalent integration constant of the driving loop and the temperature, the relationship between the phase margin of driving loop and temperature is analyzed. The effect of sense loop control parameters on the bandwidth of the gyroscope system is investigated, and the influence law between bandwidth and loop gain of the sense circuit is verified. A temperature compensation method based on an on-chip virtual temperature sensor is presented, and the design principle with an on-chip temperature compensation interface ASIC is described. The experimental results show that the standard deviation of scale factor in the temperature range of −40 to 60 °C is reduced to 11.2% of that before compensation, and the standard deviation of the zero bias is reduced to 2.5%. The zero bias instability of the gyroscope is reduced from 4.6 to 1.9°/h of that before compensation.

Accurate Nonlinearity and Temperature Compensation Method for Piezoresistive Pressure Sensors Based on Data Generation.

Piezoresistive pressure sensors exhibit inherent nonlinearity and sensitivity to ambient temperature, requiring multidimensional compensation to achieve accurate measurements. However, recent studies on software compensation mainly focused on developing advanced and intricate algorithms while neglecting the importance of calibration data and the limitation of computing resources. This paper aims to present a novel compensation method which generates more data by learning the calibration process of pressure sensors and uses a larger dataset instead of more complex models to improve the compensation effect. This method is performed by the proposed aquila optimizer optimized mixed polynomial kernel extreme learning machine (AO-MPKELM) algorithm. We conducted a detailed calibration experiment to assess the quality of the generated data and evaluate the performance of the proposed method through ablation analysis. The results demonstrate a high level of consistency between the generated and real data, with a maximum voltage deviation of only 0.71 millivolts. When using a bilinear interpolation algorithm for compensation, extra generated data can help reduce measurement errors by 78.95%, ultimately achieving 0.03% full-scale (FS) accuracy. These findings prove the proposed method is valid for high-accuracy measurements and has superior engineering applicability.

Temperature influence on optical fiber and temperature compensation method for a frequency modulation continuous wave absolute distance measurement system.

A temperature compensation method is proposed to solve the ranging precision decrease problem of the frequency-modulated continuous wave distance measurement system. The set of phases spread frequency sampling method is used to correct the beat frequency signal non-linearity. The influence model of temperature on the optical fiber auxiliary interferometer is studied. The experimental results show that distance measurement error decreases from 0.3432 mm to 0.02260 mm, and the mean measurement standard deviation decreases from 0.1088 mm to 0.01733 mm on a maximum measurement range of 1.6 m after compensation.

Gold film effect on temperature compensation of a POF sensor with different structures.

In this paper, temperature compensation of plastic optical fiber (POF) is studied and gold absorbability is utilized. Gold film is modified on the surface of POF by magnetron sputtering. The temperature output characteristics of different structures such as ordinary (POF-N), side-polished (POF-SP), U-shaped (POF-U), and narrow groove structure (POF-NGS) are tested, and the effects of gold film thickness, polishing area, and sputtering sequence on the temperature output characteristics are also investigated. The power change of the sensor at different temperatures is recorded. The experimental results show that when the temperature is between 25°C and 50°C and the sputtering gold film thickness is 50nm, the temperature stabilities of POF-N, POF-U, POF-SP, and POF-NGS are 1.02µW/°C, 0.77µW/°C, 0.18µW/°C, and 0.35µW/°C, respectively. The compensation effect is enhanced as the gold film thickness increases. When the thickness is 100nm, the temperature stability of POF-NGS is 0.06µW/°C. The proposed temperature compensation method is competitive and straightforward.

Double Optical Fiber Temperature Compensation Method for Measurement of Interface Pressure Between Simulated Cable and Accessory at High Temperatures

Reliable interface pressure between cables and accessories is closely associated with the safe operation of a power cable system. Using an external optical fiber Bragg grating temperature-compensating curvature sensor, a new method for online measurement of the interface pressure between a cable and an accessory at high temperatures is proposed. On the basis of the sensing principle of a fiber Bragg grating, a mathematical pure bending model, and a model of a thick-walled cylinder, a fiber Bragg grating temperature-compensating curvature sensor is fabricated using Dow Corning Sylgard-184 silicone rubber. The interface pressures of 10 kV cable accessories with different expansion rates at different temperatures are measured. The results of the measurements show that the temperature-compensated deviation of wavelength measurements made by the fiber grating curvature sensor ranges from -2.59% to 5.50%. The interface pressure between the cable and the accessory gradually increases with an increase in temperature from 30 to 60 °C. The results are consistent with the results of measurements made using a traditional piezoelectric sensor. This method is expected to evaluate the long-term reliability of the interface pressure of cable accessories in actual complex-temperature environments.

A novel whale-based algorithm for optimizing the ANN approach: application to temperature compensation in pressure scanner calibration systems

To resolve the nonlinear measured values of pressure scanners with temperature change during pressure measurements, resulting in low accuracy, this paper proposes and develops a new calibration system based on neural networks for pressure scanners. Specifically, we first calibrate the pressure scanner production process, then design the sealing device applicable to the working environment of pressure scanners, and finally install the calibration system of the pressure scanner for calibration experiments to obtain accurate measurement results. In addition, at the algorithmic level, this paper forwards a whale optimization algorithm-based backpropagation neural network method instead of the traditional least squares method to complete the temperature compensation. Both the offline compensation results and the compensated online experimental results exhibit the high measurement accuracy of this temperature compensation method. The full-scale (FS) error is 0.07%, the coefficient of determination (R 2) = 99.27%, with similar results for all channels of the pressure sensor in the temperature environment of −40 °C to 60 °C and absolute pressures ranging from 0 to 1.1 MPa. This result presents a significant reduction in the FS error of 0.25%, R 2 = 91.32% based on the conventional algorithm compensation, and also applies to pressure scanners with wide temperature region, wide range, and high accuracy temperature compensation, which is crucial for their future research of low-cost overall calibration and high accuracy algorithms.

Calibration Experiment and Temperature Compensation Method for the Thermal Output of Electrical Resistance Strain Gauges in Health Monitoring of Structures

Electrical resistance strain gauges are widely used in asymmetric structures for measurement and monitoring, but their thermal output in changing temperature environments has a significant impact on the measurement results. Since thermal output is related to the coefficient of thermal expansion of the strain gauge’s sensitive grating material and the measured object, the temperature self-compensation technique of strain gauges fails to eliminate the additional strain caused by temperature because it cannot match the coefficient of thermal expansion of various measured objects. To address this problem, in this study, the principle of the thermal output of electrical resistance strain gauges was analyzed, a calibration experiment for thermal output in the case of a mismatch between the coefficient of linear expansion of the measured object and the strain gauge grating material was conducted, and the mechanism for temperature influence on thermal output was revealed. A method was proposed to obtain the thermal output curves for different materials by using thermostats with dual temperatures to conduct temperature calibration experiments. A linear regression method was used to obtain a linear formula for the thermal output corresponding to each temperature. The thermal output conversion relationship was derived for materials with different coefficients of linear expansion. An in situ temperature compensation technique for electrical resistance strain gauges that separates the measured strain into thermal and mechanical strains was proposed. The results showed that the thermal output curve for the measured object can be calibrated in advance and then deducted from the measured strain, thus reducing the influence of temperature-induced additional strain on the mechanical strain. In addition, a new method was provided for the calculation of the thermal output among materials with similar coefficients of linear expansion, providing a reference for the health monitoring of asymmetric structures.

Dynamic large strain measurement under high-temperature environment using a modified FBG sensor and plasma surface treatment.

Large strain measurement under high-temperature environment has been a hot but difficult research issue in the fields of measurement and metrology. However, conventional resistive strain gauges are susceptible to electromagnetic interference at high temperature, and typical fiber sensors will be invalid under high-temperature environment or fall off under large strain conditions. In this paper, aiming to achieve effective and precision measurement of large strain under high-temperature environment, a systematic scheme combining a well-designed encapsulation of a fiber Bragg grating (FBG) sensor and a special surface treatment method using plasma is presented. The encapsulation protects the sensor from damage while achieving partial thermal isolation and avoiding shear stress and creep, resulting in higher accuracy. And the plasma surface treatment provides a new bonding solution which can greatly improve the bonding strength and coupling efficiency without damaging the surface structure of the object under test. Suitable adhesive and temperature compensation method are also carefully analyzed. Consequently, large strain measurement up to 1500 µɛ under high-temperature (1000°C) environment is experimentally achieved in a cost-effective way.