Thermocouple is a very popular and effective sensor for temperature measurement. But how to eliminate the interference of the temperature of cold junction is always a problem. A method based on recursive B-spline leas...
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Thermocouple is a very popular and effective sensor for temperature measurement. But how to eliminate the interference of the temperature of cold junction is always a problem. A method based on recursive B-spline least-squares is proposed as a solution. The method establishes two models to convert the cold junction temperature to electromotive force (EMF) and the hot junction EMF to temperature respectively. And in the middle of them, the famous law of intermediate temperature is used to translate the measured EMF into the hot junction EMF. B-spline least-squares is adopted because of its great quality of approximation. Recursive approach is used to simplify the operation and make it suitable to be used in MPU. The simulate results show that the method is of high precision and stabilization whose average relative error is only 0.01% and has a powerful ability to reduce the nonlinearity of thermocouples.
Weigh-in-motion (WIM) is a better way that can gain the true weight of vehicle which is moving on the highway at a high speed. In this paper, the principle of piezoelectric sensor is introduced, and the WIM signal mod...
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Weigh-in-motion (WIM) is a better way that can gain the true weight of vehicle which is moving on the highway at a high speed. In this paper, the principle of piezoelectric sensor is introduced, and the WIM signal model is simplified. The application of data fusion approach is used on the basis of piezoelectric sensors, and the proper redistribution of sensors is used to gain the WIM model, then the expected value which is closer to the true axle load can be gained by the Gass-Newton method. The simulation of the different speed errors when the initial phases are different according to a layout shows that the accuracy is adequate.
The possibility of estimate the velocity, axle and gross weight of a moving vehicle from the surface of pavement tensile strain is investigated. The objective is to develop the novel weigh-in-motion (WIM) technique to...
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The possibility of estimate the velocity, axle and gross weight of a moving vehicle from the surface of pavement tensile strain is investigated. The objective is to develop the novel weigh-in-motion (WIM) technique to...
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The possibility of estimate the velocity, axle and gross weight of a moving vehicle from the surface of pavement tensile strain is investigated. The objective is to develop the novel weigh-in-motion (WIM) technique to estimate the vehicle weight from the pavement responses with fewer disturbances to the vehiclepsilas vibration and traveling speed, and to provide a more reliable and durable WIM systems and sensors. A line of embedded concrete strain sensors was installed at a depth of 25cm in a surface of rigid pavement across one wheel path of the outside lane of a highway. The installation was calibrated with a truck of known weight, enabling the weights of other vehicles to be calculated and compared with weights determined by other means. Three test runs were conducted at six month intervals. Repeatability, sources of error, and accuracy of weight prediction are discussed. Successful results were obtained with this system, but further work would be required before it could be used as an operational system..
A field experiment to measure and evaluate dynamic pavement strain was carried out on existing instrumental rigid pavement slab subjected to live truck loading. The instrumental pavement test facility is constructed a...
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ISBN:
(纸本)9780784409329
A field experiment to measure and evaluate dynamic pavement strain was carried out on existing instrumental rigid pavement slab subjected to live truck loading. The instrumental pavement test facility is constructed at k220+300 of Tong-Three state road at the northeast of China. The facility consists of 5 concrete pavement sections containing 5 embedded concrete strain gages. A heavy 2-axle truck with known axle loads was used as a control vehicle. 5 embedded concrete strain gages are installed in different place under the pavement structures in sections S1 through S5. Full details regarding the construction and instrumentation of these sections will be described. Data from the instruments are collected and stored a high frequency data acquisition system is used to collect dynamic strain data of specific truck passes. The data will be process and analyze off-line. Factors which influence measured pavement structures dynamic strain are discussed by some experimental data. The method is given by this article may be serves as one of the alternative method for monitoring the structural performance of an existing pavement, are also collected data for forecast pavement service life, the fatigue analysis. Copyright ASCE 2007.
A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent Engineering of Layered Structure...
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A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent Engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.
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