Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- ...Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- mostat module maintains the sensor temperature invariable, and the heat flux sensor（Peltier device） detects the heat flux temperature difference between the thermostat module and the object surface. Two different modes of the heat flux tactile sensor are proposed, and they are simulated and experimented for different material objects. The results indicate that the heat flux tactile sensor can effectively identify different thermal properties.展开更多
Soil water content measurement is critical in practical engineering.The actively heated fiber Bragg grating optic sensor(FBGS)has great potential of multi-point measurement for soil water content measurement in field....Soil water content measurement is critical in practical engineering.The actively heated fiber Bragg grating optic sensor(FBGS)has great potential of multi-point measurement for soil water content measurement in field.In this study,the effect of heating time on the measurement accuracy is discussed,and modifications are made for actively heated fiber optic(AHFO)sensors.The results demonstrate that if an integration data analysis method is used,the accuracy and reliability of soil water content measurement with AHFO sensors will be improved.Both a short fiber length and a short-term heating pattern are effective and can help to reduce soil disturbance.With the proposed integration method,a short heating time is guaranteed for measuring the soil water content.Such improvements will reduce the thermal disturbance to soil sample and improve the reliability of measurement.展开更多
The ability to measure the very high heat fluxes that typically occur during the hypersonic re-entry phase of space vehicles is generally considered a subject of great importance in the aerospace field.Most of the sen...The ability to measure the very high heat fluxes that typically occur during the hypersonic re-entry phase of space vehicles is generally considered a subject of great importance in the aerospace field.Most of the sensors used for these measurements need to be checked periodically and re-calibrated accordingly.Another bottleneck relates to the need to procure thermal sources that are able to generate reliable reference heat fluxes in the range between 100 and 1000 kW/m^(2)(as order of magnitude).In the present study,a method is presented by which,starting from a calibration system with a capacity of approximately 500 kW/m^(2) only,heat fluxes in the range of interest for hypersonic applications are generated.The related procedure takes advantage of established standards for the characterization of a radiative heat flux.It also builds on the hybrid radiative-convective nature of typical hypersonic heat fluxes and the yet poorly explored possibility to use convective sources of heat to produce high-intensity fluxes.The reliability of such a strategy has been tested using a high enthalpy supersonic flow facility relying on an electric arc-heater and pure Nitrogen as work gas.Stagnation-point heat fluxes have been successfully measured(with reasonable accuracy)in the range between 600 and 1500 kW/m^(2) for values of the centerline enthalpy spanning the interval from to 6 to 24 MJ/kg.展开更多
The need for developing accurate quenching models requires an extensive experimental database that includes surface heat flux characterization. Quantification of the quenching process permits i) the development of hig...The need for developing accurate quenching models requires an extensive experimental database that includes surface heat flux characterization. Quantification of the quenching process permits i) the development of high-quality heat treated products, ii) the evaluation of new quenchants and quenchant systems, and iii) the evaluation of quenchant quality over usage time. The surface heat transfer coefficient (or heat flux) is rarely measured, calculated or modeled in sufficient detail for real scientific use. Many single-thermocouple based probes are designed for the purpose of measuring the cooling power of a liquid quenchant or for monitoring quenchant quality. Lumped based probes are sufficient for these types of applications. However, the lack of sufficient distributed detail impedes the development of future high-quality heat-treated products. Frankel and his coworkers are developing a new family of transient thermal-rate sensors that will improve both diagnostic and real-time analyzes in heat transfer studies. Analyzes have been performed indicating that there exists a novel, thermal-rate sensor hierarchy that stabilizes predictions when used with analysis. This concept can be used for investigating both (i) direct surface heat transfer effects, and (ii) projective surface analysis based on embedded sensors. This new sensor family includes the ability to measure temperature, T; heat flux, q"; and their temporal derivatives, i.e., dT/dt, d^T/dt2 and dq’Vdt.展开更多
Compression force sensors are indispensable to tactile sensors in humanoid robots. We are investigating the application of low-cost electrically conducting rubber sheets to force sensors, of which the biggest problem ...Compression force sensors are indispensable to tactile sensors in humanoid robots. We are investigating the application of low-cost electrically conducting rubber sheets to force sensors, of which the biggest problem is its poor reproducibility. We have found that the deposition of aluminum by a vacuum evaporation method shows such an excellent characteristic that the sensor can be used in a wide range under 10.33 N/cm2. In this article, we investigated time response of the sensors and also studied how the radiation heating during the vacuum evaporation process for Al deposition affected their sensing property. We found that the radiation heating induces deterioration from the point of view of standard deviation of the output voltage of the sensors at a transient region. We convince that a low-temperature Al deposition method should be developed to form electrodes on the electrical conducting rubber sensors.展开更多
Activity recognition of indoor occupants using indirect sensing with less privacy violation is one of the hot research topics. This paper proposes a CO<sub>2</sub> sensor-based indoor occupant activity mon...Activity recognition of indoor occupants using indirect sensing with less privacy violation is one of the hot research topics. This paper proposes a CO<sub>2</sub> sensor-based indoor occupant activity monitoring system. Using the IoT sensor node that contains CO<sub>2</sub> sensors, the measured CO<sub>2</sub> concentrations in three locations (laboratory, office, and bedroom) were stored in a cloud server for up to 35 days starting July 1, 2023. The CO<sub>2</sub> measurements stored at 30-second intervals were statistically processed to produce a heat-mapped display of the hourly average or maximum CO<sub>2</sub> concentration. From the heatmap visualizations of CO<sub>2</sub> concentration, the proposed system estimated meeting, heating water using a portable stove, and sleep for the occupants’ activity recognition.展开更多
基金Supported by the National High Technology Research and Development Program of China(″863″Program)(2009AA01Z314,2009AA01Z311)the Jiangsu Province Natural Science Foundation(BK2009272)theJiangsu Province″333″Program~~
文摘Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- mostat module maintains the sensor temperature invariable, and the heat flux sensor（Peltier device） detects the heat flux temperature difference between the thermostat module and the object surface. Two different modes of the heat flux tactile sensor are proposed, and they are simulated and experimented for different material objects. The results indicate that the heat flux tactile sensor can effectively identify different thermal properties.
基金supported by the National Natural Science Foundation of China(Grant No.51979002).
文摘Soil water content measurement is critical in practical engineering.The actively heated fiber Bragg grating optic sensor(FBGS)has great potential of multi-point measurement for soil water content measurement in field.In this study,the effect of heating time on the measurement accuracy is discussed,and modifications are made for actively heated fiber optic(AHFO)sensors.The results demonstrate that if an integration data analysis method is used,the accuracy and reliability of soil water content measurement with AHFO sensors will be improved.Both a short fiber length and a short-term heating pattern are effective and can help to reduce soil disturbance.With the proposed integration method,a short heating time is guaranteed for measuring the soil water content.Such improvements will reduce the thermal disturbance to soil sample and improve the reliability of measurement.
文摘The ability to measure the very high heat fluxes that typically occur during the hypersonic re-entry phase of space vehicles is generally considered a subject of great importance in the aerospace field.Most of the sensors used for these measurements need to be checked periodically and re-calibrated accordingly.Another bottleneck relates to the need to procure thermal sources that are able to generate reliable reference heat fluxes in the range between 100 and 1000 kW/m^(2)(as order of magnitude).In the present study,a method is presented by which,starting from a calibration system with a capacity of approximately 500 kW/m^(2) only,heat fluxes in the range of interest for hypersonic applications are generated.The related procedure takes advantage of established standards for the characterization of a radiative heat flux.It also builds on the hybrid radiative-convective nature of typical hypersonic heat fluxes and the yet poorly explored possibility to use convective sources of heat to produce high-intensity fluxes.The reliability of such a strategy has been tested using a high enthalpy supersonic flow facility relying on an electric arc-heater and pure Nitrogen as work gas.Stagnation-point heat fluxes have been successfully measured(with reasonable accuracy)in the range between 600 and 1500 kW/m^(2) for values of the centerline enthalpy spanning the interval from to 6 to 24 MJ/kg.
文摘The need for developing accurate quenching models requires an extensive experimental database that includes surface heat flux characterization. Quantification of the quenching process permits i) the development of high-quality heat treated products, ii) the evaluation of new quenchants and quenchant systems, and iii) the evaluation of quenchant quality over usage time. The surface heat transfer coefficient (or heat flux) is rarely measured, calculated or modeled in sufficient detail for real scientific use. Many single-thermocouple based probes are designed for the purpose of measuring the cooling power of a liquid quenchant or for monitoring quenchant quality. Lumped based probes are sufficient for these types of applications. However, the lack of sufficient distributed detail impedes the development of future high-quality heat-treated products. Frankel and his coworkers are developing a new family of transient thermal-rate sensors that will improve both diagnostic and real-time analyzes in heat transfer studies. Analyzes have been performed indicating that there exists a novel, thermal-rate sensor hierarchy that stabilizes predictions when used with analysis. This concept can be used for investigating both (i) direct surface heat transfer effects, and (ii) projective surface analysis based on embedded sensors. This new sensor family includes the ability to measure temperature, T; heat flux, q"; and their temporal derivatives, i.e., dT/dt, d^T/dt2 and dq’Vdt.
文摘Compression force sensors are indispensable to tactile sensors in humanoid robots. We are investigating the application of low-cost electrically conducting rubber sheets to force sensors, of which the biggest problem is its poor reproducibility. We have found that the deposition of aluminum by a vacuum evaporation method shows such an excellent characteristic that the sensor can be used in a wide range under 10.33 N/cm2. In this article, we investigated time response of the sensors and also studied how the radiation heating during the vacuum evaporation process for Al deposition affected their sensing property. We found that the radiation heating induces deterioration from the point of view of standard deviation of the output voltage of the sensors at a transient region. We convince that a low-temperature Al deposition method should be developed to form electrodes on the electrical conducting rubber sensors.
文摘Activity recognition of indoor occupants using indirect sensing with less privacy violation is one of the hot research topics. This paper proposes a CO<sub>2</sub> sensor-based indoor occupant activity monitoring system. Using the IoT sensor node that contains CO<sub>2</sub> sensors, the measured CO<sub>2</sub> concentrations in three locations (laboratory, office, and bedroom) were stored in a cloud server for up to 35 days starting July 1, 2023. The CO<sub>2</sub> measurements stored at 30-second intervals were statistically processed to produce a heat-mapped display of the hourly average or maximum CO<sub>2</sub> concentration. From the heatmap visualizations of CO<sub>2</sub> concentration, the proposed system estimated meeting, heating water using a portable stove, and sleep for the occupants’ activity recognition.
