Research On Ultrasonic Detection Technique Of Flux And Pressure For Hydraulic System

Hydraulic system have been used widely, with light structure, large transmission ratio and running placidity, in weapons and equipments in the Second Artillery Troop. Compared with electrical or mechanic system, hydraulic system have the disadvantages of high fault frequency and difficulties to diagnosis, which have greatly effected battle effectiveness in warfare. Flux and pressure parameters which hold the state information of hydraulic system, are the foundation of fault diagnosis. The traditional interposed measurements have trouble in disassembly and bad impact on hydraulic dynamic characteristic, which doesn't suit high speed fault diagnosis for weapons and equipments. A new method for non-interposed testing to the flux and pressure parameters is proposed with ultrasonic. Based on the new method, on-line fault diagnosis for weapons and equipments is achieved.According to the high dispersedness and low precision of measurements when using the traditional time difference method in small diameter and low flow rates conditon, this paper brings forward a new method based on high-speed data acquisition technique. The time difference comes out accurately with high resolving ability of time by using the method and the signal processing algorithms.The developed ultrasonic detection system is composed of two ultrasonic detectors, a transmitting and receiving ultrasonic unit, a high-speed data acquisition unit and a computer. The system accomplishes ultrasonic pulse transmitting and receiving, signal amplitude adaptive adjusting, data acquiring, echo searching, data processing and analyzing. Different algorithms for echo searching, filtering and time difference measuring are proposed based on the thorough analysis of ultrasonic echo signal. By means of the echo auto-searching algorithm, the automatization of signal processing is realized. The filter algorithms are given to eliminate electric and pulse noise, the measuring reliability is improved greatly. Furthermore, the accuracy of time difference measure is improved greatly by using the correlation algorithm and the wavelet algorithm. The realizing methods for the algorithms are presented also.A hydraulic experiment system is established to simulate the different states of hydraulic system, with a pump, several valves, turbo-flowmeter, pressure gauge, and many hydraulic pipelines of different diameter.Experiment indicates that the convenience, speedness, precision and reliability of...