scholarly journals A temperature compensation method of measuring frequency for cylindrical vibratory gyroscope in frequency split trimming

2018 ◽  
Vol 175 ◽  
pp. 03042
Author(s):  
Youwang Hu ◽  
Kai Zeng ◽  
Haofang Wang ◽  
Chang Liang ◽  
Yongping Zhou ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Temperature Compensation ◽  
Environmental Temperature ◽  
Measuring Method ◽  
Frequency Measurement ◽  
Effect Of Temperature ◽  
Vibratory Gyroscope ◽  
Before And After ◽  
Measuring Frequency ◽  
Frequency Split

In the process of frequency split trimming, the fluctuation of environmental temperature causes a deviation in measuring the natural frequency, which is bigger than the request trimming accuracy. Therefore, a measuring method with temperature compensation is proposed to reduce this impact. Firstly, the relationship between natural frequency of resonator and environmental temperature are studied by experiments. Furthermore, the corresponding model of temperature compensation is proposed, which is written into the measuring unit to calculate the compensated frequency. The frequencies before and after temperature compensation are measured to prove the correctness of this method. At last, a real time measuring experiment is accomplished to verify the feasibility in frequency split trimming. Results show that the effect of temperature on the natural frequency reduced significantly with the temperature compensation measuring method. The proposed method is applicable for other types of vibratory gyroscope in precision frequency measurement.

scholarly journals Temperature Compensation Method for Raster Projectors Used in 3D Structured Light Scanners

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5778
Author(s):  
Marcin Adamczyk
Keyword(s):  
Thermal Effects ◽  
Temperature Compensation ◽  
Measurement Method ◽  
Environmental Temperature ◽  
Structured Light ◽  
Three Dimensional ◽  
Compensation Method ◽  
Effect Of Temperature ◽  
Significant Deterioration ◽  
Effects Of Temperature

Raster projectors are commonly used in many various measurement applications where active lighting is required, such as in three-dimensional structured light scanners. The effect of temperature on the raster projector, in some conditions, can lead to significant deterioration of the measurements performed with such a scanner. In this paper, the outcomes of several experiments concerning the effects of temperature on raster projectors are presented. The described research is focused on the thermal deformations of projected images caused by common thermal effects observed in projectors: those caused by the warming-up process and changes in ambient environmental temperature. A software compensation method is also presented. It is suitable for implementation in any existing measurement method that uses raster projectors. The results of performed verification experiments show that the developed compensation method can decrease the thermal drift of the projected images by up to 14 times in the ambient temperature range 14–42 °C.

Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran
Keyword(s):  
Environmental Temperature ◽  
Extreme Temperature ◽  
Effect Of Temperature ◽  
Maximum Speed ◽  
Locomotor Performance ◽  
Extreme Temperatures ◽  
Physiological Limits ◽  
Fitness Consequences ◽  
Thermal Maximum ◽  
Environmental Temperatures

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.

scholarly journals A Vibration-Based Structural Health Monitoring System for Transmission Line Towers

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 515 ◽  
Author(s):  
Long Zhao ◽  
Xinbo Huang ◽  
Ye Zhang ◽  
Yi Tian ◽  
Yu Zhao
Keyword(s):  
Structural Health Monitoring ◽  
Transmission Line ◽  
Natural Frequency ◽  
Health Monitoring ◽  
Structural Changes ◽  
Natural Frequencies ◽  
Transmission Tower ◽  
Health Monitoring System ◽  
Wind Speeds ◽  
Before And After

In this paper, we present a vibration-based transmission tower structural health monitoring system consisting of two parts that identifies structural changes in towers. An accelerometer group realizes vibration response acquisition at different positions and reduces the risk of data loss by data compression technology. A solar cell provides the power supply. An analyser receives the data from the acceleration sensor group and calculates the transmission tower natural frequencies, and the change in the structure is determined based on natural frequencies. Then, the data are sent to the monitoring center. Furthermore, analysis of the vibration signal and the calculation method of natural frequencies are proposed. The response and natural frequencies of vibration at different wind speeds are analysed by time-domain signal, power spectral density (PSD), root mean square (RMS) and short-time Fouier transform (STFT). The natural frequency identification of the overall structure by the stochastic subspace identification (SSI) method reveals that the number of natural frequencies that can be calculated at different wind speeds is different, but the 2nd, 3rd and 4th natural frequencies can be excited. Finally, the system was tested on a 110 kV experimental transmission line. After 18 h of experimentation, the natural frequency of the overall structure of the transmission tower was determined before and after the tower leg was lifted. The results show that before and after the tower leg is lifted, the natural frequencies of each order exhibit obvious changes, and the differences in the average values can be used as the basis for judging the structural changes of the tower.

Design of Ultrasonic Ranging Circuit Based on STC Microcontroller

2013 ◽  
Vol 722 ◽  
pp. 59-63
Author(s):  
Rui Luo ◽  
Zi Hong Zhang
Keyword(s):  
System Performance ◽  
Temperature Compensation ◽  
Measurement Accuracy ◽  
Environmental Temperature ◽  
Detection Distance ◽  
Compensation Circuit ◽  
High Measurement ◽  
Ultrasonic Ranging ◽  
Allowable Range ◽  
Market Promotion

In this paper, based on the 18B20 temperature compensation circuit for ultrasonic ranging circuit, can eliminate the influence of environmental temperature on ultrasonic velocity, this paper introduced the ultrasonic ranging system, the system includes ultrasonic transmitting circuit, receiving circuit and display circuit, the results of the experiment show that, the system detection distance can be up to 12M, the error is in the allowable range, the range finder the system performance is stable, high measurement accuracy, distance, has a certain practicality and market promotion value.

Application of Benzotriazole Corrosion Inhibitor in Synthetic-Based Drilling Fluid and its Overall Impact in Improving Drilling Fluid Functionality

2021 ◽  
Author(s):  
Zhao Xionghu ◽  
Saviour Bassey Egwu ◽  
Deng Jingen ◽  
Miao Liujie
Keyword(s):  
Corrosion Rate ◽  
Corrosion Inhibitor ◽  
Coefficient Of Friction ◽  
Hot Rolling ◽  
Drilling Fluid ◽  
Effect Of Temperature ◽  
Fluid Loss ◽  
Fluid Composition ◽  
Fluid System ◽  
Before And After

Abstract The effect of corrosion inhibitor Benzotriazole on synthetic-based mud system was studied. Rheological performance of the benzotriazole enhanced synthetic-based fluid system was studied and compared against the base mud. To study its effect on dynamic wellbore conditions, different drilling fluid compositions were placed in a hot rolling oven for 16 hours at temperatures 150 °C and 170°C and the effect of temperature on mud properties were studied. Tests carried out include rheological test (before and after hot rolling), filtrate pH, lubricity test, and fluid loss test. The corrosion penetration rate was studied using the weight loss method. Based on experiment results, the synthetic-based mud system which comprised of benzotriazole displayed a reduction in coefficient of friction up to 95.93%. At ambient condition, optimal ratio of mineral oil:benzotriazole (M:B) which gives best lubricity performance on synthetic-based mud system is 80:20. This leads to improved corrosion inhibition and lubricity of the synthetic-based fluid by reducing the coefficient of friction up to 90.13%. Increased temperature led to further decrease in coefficient of friction with a % torque reduction of 95.93 displayed by the 80:20 ratio M:B mud composition at 170 °C. Significant alterations of the mud composition rheological and fluid loss parameters before and after exposure to high temperature in hot rolling oven were not observed. pH values were maintained ≥7 at the dynamic conditions highlighting solubility of the formulated fluid composition and absence of contaminants which can pose significant threats to the rates of corrosion in drill pipes. Increasing the concentration of Benzotriazole led to a reduction in corrosion rate. However, as the temperature effect increased, the corrosion rate elevated. Based on results from this investigation, it was concluded that Benzotriazole can be applied as a corrosion inhibitor in a synthetic-based drilling fluid system as an alternative corrosion inhibitor without significant alteration of the base mud properties. Benefits of this will be the optimization of extended reach well drilling operations due to excellent lubricity performance, corrosion rate reduction, compatibility with HPHT wellbore condition and fluid loss control.

An Optimal Sensitivity-Enhancing Feedback Control Approach via Eigenstructure Assignment for Structural Damage Identification

2007 ◽  
Vol 129 (6) ◽  
pp. 771-783 ◽  
Author(s):  
L. J. Jiang ◽  
J. Tang ◽  
K. W. Wang
Keyword(s):  
Feedback Control ◽  
Frequency Shift ◽  
Natural Frequency ◽  
Structural Damage ◽  
Closed Loop ◽  
Damage Identification ◽  
Frequency Measurement ◽  
Sensitivity Enhancement ◽  
Stiffness Reduction ◽  
Structural Damage Identification

The concept of using sensitivity-enhancing feedback control to improve the performance of frequency-shift-based structural damage identification has been recently explored. In previous studies, however, the feedback controller is designed to alter only the closed-loop eigenvalues, and the effect of closed-loop eigenvectors on the sensitivity enhancement performance has not been considered. In this research, it is shown that the sensitivity of the natural frequency shift to the damage in a multi-degree-of-freedom structure can be significantly influenced by the placement of both the eigenvalues and the eigenvectors. A constrained optimization problem is formulated to find the optimal assignment of both the closed-loop eigenvalues and eigenvectors, and then an optimal sensitivity-enhancing control is designed to achieve the desired closed-loop eigenstructure. Another advantage of this scheme is that the dataset of frequency measurement for damage identification can be enlarged by utilizing a series of closed-loop controls, which can be realized by activating different combinations of actuators in the system. Therefore, by using this proposed idea of multiple sensitivity-enhancing feedback controls, we can simultaneously address the two major limitations of frequency-shift-based damage identification: the low sensitivity of frequency shift to damage effects and the deficiency of frequency measurement data. A series of case studies are performed. It is demonstrated that the sensitivity of natural frequency shift to stiffness reduction can be significantly enhanced by using the designed sensitivity-enhancing feedback control, where the optimal placement of closed-loop eigenvectors plays a very important role. It is further verified that such sensitivity enhancement can directly benefit the damage identification accuracy and robustness.

Influence of the environmental temperature on the post-partum testosterone surge in the rat

1987 ◽  
Vol 115 (4) ◽  
pp. 478-482 ◽  
Author(s):  
J. Roffi ◽  
F. Chami ◽  
P. Corbier ◽  
D. A. Edwards
Keyword(s):  
Ambient Temperature ◽  
Environmental Temperature ◽  
Post Partum ◽  
Serum Testosterone ◽  
The Body ◽  
Male Rats ◽  
Effect Of Temperature ◽  
Male Rat ◽  
Foster Mother ◽  
The Central Nervous System

Abstract. In the neonatal male rat, a rapid and transient increase in serum testosterone occurs about 2 h after birth. This post-partum testosterone surge (PPTS) has been implicated in the masculinization and defeminization of the central nervous system. The present study shows that environmental temperature can have a profound influence on the PPTS. Male rats were delivered from their mothers by caesarean section on day 22 of gestation. Immediately thereafter, neonatal males were placed at an ambient temperature of either 18, 21, 24 or 30°C. With 2 h of exposure, the body temperature was in close correspondence with the ambient temperature. The PPTS was clearly abolished in the pups exposed for 2 h at either 18 or 21°C. The effect of temperature was reversible: by placing pups at either 18 or 21°C for 2 h after delivery, and then rewarming by placing them with a foster mother, the PPTS was delayed until 4 h after birth, i.e. 2 h after the beginning of rewarming. Thus, environmental cooling appears to retard the development of neural and/or endocrine systems mediating the PPTS. Aberrant maternal care which would produce substantial cooling of the male pups would be expected to affect the PPTS, which in turn might affect the sexuality of male progeny.

scholarly journals Temperature Compensation Method for Digital Cameras in 2D and 3D Measurement Applications

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3685 ◽  
Author(s):  
Marcin Adamczyk ◽  
Paweł Liberadzki ◽  
Robert Sitnik
Keyword(s):  
Temperature Compensation ◽  
Three Dimensional ◽  
Compensation Method ◽  
Effect Of Temperature ◽  
Calibration Model ◽  
Digital Cameras ◽  
Compensation Model ◽  
Camera Design ◽  
Compensation Approach ◽  
2D And 3D

This paper presents the results of several studies concerning the effect of temperature on digital cameras. Experiments were performed using three different camera models. The presented results conclusively demonstrate that the typical camera design does not adequately take into account the effect of temperature variation on the device’s performance. In this regard, a modified camera design is proposed that exhibits a highly predictable behavior under varying ambient temperature and facilitates thermal compensation. A novel temperature compensation method is also proposed. This compensation model can be applied in almost every existing camera application, as it is compatible with every camera calibration model. A two-dimensional (2D) and three-dimensional (3D) application of the proposed compensation model is also described. The results of the application of the proposed compensation approach are presented herein.

scholarly journals Effect of Temperature on the Tribological Properties of Selected Thermoplastic Materials Cooperating with Aluminium Alloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7318
Author(s):  
Anita Ptak ◽  
Paula Taciak ◽  
Wojciech Wieleba
Keyword(s):  
Aluminium Alloy ◽  
Contact Pressure ◽  
Tribological Properties ◽  
Polymer Materials ◽  
Effect Of Temperature ◽  
Test Results ◽  
Friction Process ◽  
Before And After ◽  
Pin On Disc ◽  
Two Parameters

This article concerns the tribological properties of three selected polymer materials: polyamide PA6, polyethylene PE-HD and polyetheretherketone composite PEEK/BG during sliding against aluminium alloy EN AW-2017A in the presence of hydraulic oil HLP 68. The tests were carried out under contact pressure p of 3.5–11 MPa at ambient temperature T ranging from −20 °C to +20 °C. The dependence of kinetic friction coefficient μk on the two parameters was determined through tribological tests carried out using a pin-on-disc tribometer. A five-level central composite rotatable design (CCRD) was adopted for the experiment. All the test results were statistically analysed. The microhardness of the surface of the polymeric material was measured before and after the friction process. The surface was also examined under SEM. Temperature and contact pressure have been found to have a significant effect on the tribological properties of the tested sliding pairs. Relative to the applied friction conditions, the surfaces after friction showed rather heavy signs of wear.

scholarly journals MECHANICAL CHARACTERIZATION OF PA 12 AND HDPE PIPES BEFORE AND AFTER AGING IN WATER AT TWO DIFFERENT TEMPERATURES

2021 ◽  
Vol 9 (1) ◽  
pp. 248-256
Author(s):  
J.A. dos Santos ◽  
R.C. Tucunduva ◽  
J.R.M. D’Almeida
Keyword(s):  
High Density Polyethylene ◽  
Mechanical Performance ◽  
High Density ◽  
Effect Of Temperature ◽  
Polyamide 12 ◽  
Polyethylene Pipes ◽  
Before And After ◽  
Different Temperatures ◽  
Deterioration Process ◽  
Combined Action

Polymer pipes are being widely used by many industrial segments. Although not affected by corrosion, the mechanical performance of these pipes can be reduced due to exposure to temperature, UV radiation and by contact with various fluids. Depending on the deterioration process, embrittlement or plasticization may occur, and the service life of the pipe can be severely reduced. In this work, the combined action of temperature and water upon the mechanical performance of polyamide 12 and high-density polyethylene pipes is evaluated. Destructive and non-destructive techniques were used and the performance of both materials was compared. Both polymers were platicized by the effect of water. However, for high density polyethylene the effect of temperature was more relevant than for polyamide. This behavior was attributed to the dependence of the free volume with the markedly different glass transition temperature of the polymers and the temperatures of testing.

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