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Hydraulic system, the internal pressure of the gas or liquid pipeline detection methods and means of monitoring pipeline system running state and the pipeline fault diagnosis. Hydraulic measurements intrusive measurement mechanical pressure gauge, strain gauge, piezoresistive, vibrating wire and other pressure measuring method. The biggest drawback of these methods is that they all belong to the intrusive measurement, pressure measurement interface need to set aside, poor reliability, fault location is difficult, and destroy the structural integrity of the piping, especially under high pressure conditions, and is easy to leave the security risks. Therefore, the study of non-intervention the pipeline the manometry theory and methods, and the development of a non-invasive pressure measurement device has important practical significance and broad prospect. Thesis and a non-intrusive the pipeline pressure measurement technology and methods, the use of ultrasound as a piping pressure test means. This is the nature of the ultrasonic wave propagation characteristics based on the fluid in the parameters (such as attenuation coefficient, sonic, etc.) sensitive to pressure changes. Since the acoustic attenuation coefficient in the detection process, there are many uncertainties, vulnerable to the interference of external conditions, so this article select the sound velocity as a measurement object: In the case of fixed sound process, the measurement of the sound velocity is converted to the ultrasonic wave propagation delay measurement. Further, since the temperature of great influence on the speed of sound of the ultrasonic need to measure the exact temperature value. Currently, the ultrasonic the pipeline pressure measurement technology is still in the study of the early stages, yet a mature domestic facilitate the use of non-intrusive pressure measurement technique or device. This paper studies and the relevant ultrasonic the manometry principle, to establish the relationship between the ULTRASONIC liquid pressure model. On this basis, the paper followed by hardware circuit design and debugging, including ultrasonic pulse transmitter circuit, signal conditioning circuits, A / D conversion circuit, CPLD control circuit. Then, since the measured signal the presence of noise, in order to effectively extract the delay parameters, it is necessary on the ultrasonic signal processing. So this paper, and a sparse component decomposition technique precise method for solving the ultrasonic echo delay. The method according to the characteristics of the signal itself from a redundant function set selection basis function, to represent the observed signals to be analyzed, thereby obtaining the most effective signal decomposition. Experimental studies have shown that, compared with traditional hardware circuits notation and peak - peak sparse component decomposition can accurately calculate the ultrasonic echo delay, to improve the accuracy of the pressure measurement. Sparse component analysis techniques to precisely calculate the ultrasonic echo delay, and finally the use of neural network training to get the relationship between pressure and ultrasonic delay characteristics model. Studies have shown that ultrasound manometry method is feasible, the pressure and the speed of sound association can provide reference for the further study of the technology.
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