Based On The Data-extraction Technology In The Distributed Measurement System For Testing Transient Pressure

Explosion shock wave is an important index for evaluating the damage efficiency of ammunition, accurate measurement of blast shock wave plays an important significance in evaluating weapon performance. With the improvement of the test requirements, the number of test nodes are increasing and the distribution range is becoming more and more extensive,lead wire measuring methods has been unable to meet test requirements, wireless distributed test system solves the inconvenience of the long line wiring and has been develop rapidly. In the explosion field, when the test nodes are installed, the wireless network will be shut down,so the working status of the system can not be detected in real time, then the false trigger due to different interference can cause the test to fail. Through large capacity data storage to achieve long-time signal acquisition, which gets rid of trigger mode. But for dozens of measuring points in the pressure filed test, this approach will bring hundreds of G data and resulting difficult to read.A data-extraction technology in the distributed measurement system for testing transient pressure is proposed in this paper based on wireless distributed transient pressure testing technology. Large capacity data storage is designed in this measurement to get rid of trigger mode, at the same time, the data-extraction technology is used to read data, which improves the rate of data transmission and processing. In this paper, the NAND Flash can storage data for more than two hours continuously at the sampling frequency of 1Msps is selected to meet the long time data storage requirements. The real-time data monitoring and the mark of effective data segment are needed in the process data collection and storage. If the instantaneous value of the data is greater than the threshold voltage, the point of instantaneous value is called effective mutation point and the corresponding data segment is called effectivedata segment. Due to the effect of the jamming signal, more than one effective data segment was marked. Therefore, when the data collection is completed, the target data segment should be extracted from the effective data segment. There are two ways to extract the target data segment, which are based on time information extraction and based on feature information extraction. A measurement system based on data-extraction technology was designed and applied in an explosion field, the measurement system has programmable magnification and threshold voltage and it was characterized by sampling frequency of 1Msps, the effective data segment length 512 KWord, the memory storage capacity of 128 Gb, and the coverage of Wi-Fi wireless network.