Papers by Keyword: Temperature Compensation

Abstract: This paper focuses on the simulation of clutch engagement behavior in automated manual transmissions (AMTs) to virtualize the vehicle start-up maneuver through implementation of the driveline model and the role of transmission control unit featuring different levels of knowledge regarding to clutch material frictional response. Simulation results underline the crucial requirement of accurate prediction of the frictional coefficient evolution in each clutch maneuver, particularly regarding to the interface temperature estimation to develop effective models and control algorithms.

Abstract: In this paper, a novel monolithically integrated flexible thermal flow sensor combining four resistors in a Wheatstone bridge including hot-film resistor, temperature-compensating resistor and two other balancing resistors on one chip is proposed in order to improve the system integration level and sensor performances, such as signal to noise ratio (SNR), power consumption and temperature compensation. Fabricating the sensor directly on a flexible polyimide printed circuit board (PCB) by incorporating printed circuit technique with micromachining sputter technique is adopted. A complete performance test on the flow sensor demonstrates its superiorities on power consumption, SNR and temperature drift, the error of which is eliminated from 43% to 8% over a range of ambient temperature (35–75°C).

Abstract: Introduced the development situation and trend of structural health monitoring, discussed the advantages and insufficiencies of application issues of the structural health monitoring system based on optical fiber sensing technology, combined with engineering case, analyzed the sensors’ survival rate, system reliability, temperature compensation and some other issues, according to the specific problem proposed the corresponding solutions or concrete measure.

Abstract: Trouble-free operation of large-scale mechanical equipment is of great significance to modern industrial production. The existing wireless sensor network nodes are not suitable for condition monitoring of mechanical equipment due to their low acquisition accuracy. In view of this, this article put forward a wireless sensor network for mechanical condition monitoring, and designed corresponding wireless sensor network nodes. These nodes could achieve high-precision acquisition of analog signals. This article described a wireless sensor network structure for mechanical condition monitoring, hardware design of wireless sensor nodes and software design of the system. The precision of the wireless sensor network nodes we designed was verified by experiment. The experiment result showed that the nodes could effectively acquire analog signal with high precision.

Abstract: A variable value water resistor speed control system for rotor winding induction motor is introduced. On the basis of the structure about the water resistance and the governor principle, the steady-state mathematical model and the dynamic mathematical models are established. The effect of temperature changes on the resistance of the electrolyte solution is discussed, and temperature compensation is proposed. Simulation results show that the water resistance speed control system is feasible.

Abstract: FBG (Fiber Bragg Grating) is a new type of optical passive device which can be used in sensing field. This paper demonstrates the feasibility and effectiveness of FBG as the new method of strain measurement, and improves the measuring precision. Based on the strain sensing property of FBG, the study adopts the differential method of double FBGs to make temperature compensation, and conduct the contrast experiment with resistance strain chip. The experimental results show that strain measurement based on FBG agrees well with theoretical calculation. The measurement error: no more than 1%, linear fitting correlation coefficient: almost 1, linearity: 0.17%, sensitivity: 7.92, hysteresis error: 0.347%, repeatability error: 0.333%. The results show FBG’s performance are superior to resistance strain chip, especially in aspect of measuring precision. Therefore, we can conclude that FBG is a feasible and effective method of strain measurement.

Abstract: A method to reduce temperature effects in SAW pressure sensors is presented. A layer of SiO2 is deposited on the surface of 128YX LiNbO3 in order to achieve a high coupling coefficient (κ²) as well as a low temperature coefficient of delay (TCD). The FEM tool COMSOL Multiphysics is used to estimate the phase velocity and frequency of the input RF signal using an eigenfrequency analysis. Then by using a time domain analysis, a surface acoustic wave (SAW) is generated by IDTs and its wave propagation characteristics are obtained. During this process, the boundary reflection is removed by adding a perfectly matched layer (PML). The reflected signal on the IDT can be detected; as such the phase angle is calculated. By applying different pressures to the sensor, a relationship between pressure and phase angle is determined. Using frequency domain analysis, the coupling coefficient is computed with high accuracy. The TCD is calculated at different SiO2 thicknesses and the SiO2 thickness corresponding to a zero TCD and high coupling coefficient is obtained. A prototype is tested to validate these values.

Abstract: In this paper, a wideband variable-gain amplifier (VGA) in CMOS for ultra wideband (UWB) system is designed. The operation frequency of the VGA is 4.2-4.8GHz, and the gain is continuously adjustable between 0 and 30dB. Cascaded Cherry-Hooper with two stages is adopted as the core unit of the VGA, and a temperature compensation circuit is used to reduce the effect of temperature on the performance of the system. The simulation shows that the temperature compensation circuit can compensate the effect of the temperature very well, and the noise figure of the wideband VGA can meet the requirements of the system.

Abstract: This paper has presented a bandgap reference circuit with high-order temperature compensation. The compensation technique is achieved by using MOS transistor operating in sub-threshold region for reducing high-order TC of V_be. The circuit is designed in 0.18¦Ìm CMOS process. Simulation results show that the proposed circuit achieves 4.2 ppm/¡æ with temperature from-55 to 125 ¡æ, which is only a third than that of first-order compensated bandgap reference.

Abstract: Geological structure health in mountainous area substation is complex, and the climate is changeable, it is easy to appear the geological disasters like landslide and subsidence in substation, Aiming at the strong electromagnetic interference in substation and other factors, to monitor of slope surface strain of mountainous area substation with FBG strain sensor, in order to reflect the stability of the slope. Combined with the actual situation of slope of Yunnan 220kV mountainous area substation, the surface type FBG strian sensors are installed on the surface of upstream and downstream slope of mountainous area substation, the lower reaches of the substation, the serial network forms a quasi distributed optical fiber sensing network. they form a quasi-distributed optical fiber sensing network through the serial networking methods.When the slope surface occurs deformation due to the soil sliding, it will drive the FBG strain sensor and transfer the equal strain to the FBG strain sensor. By measuring the center wavelength shift of the FBG strian sensor, the strian value of slope surface at each point can be reflected. The monitoring results show that, the period from May 9th to June 6th, the maximum strain of upstream slope is 171uɛ, it appears at the location of marked as US4 FBG strain sensor, the maximum strain of downstream slope is 112uɛ,it appears at the location of marked as DS1 FBG strain sensor.