The Research And Design Of Data Acquisition System Applied To Distributed Testing

The essence of this article is to study the data gathering technology of aquatic explosion field Shockwave and bubble power efficiency parameters.First, for the integrality of explosion signal acquisition, based on the characteristic of single and momentary, a method of integral test and the self-adjust trigger threshold is designed. Meanwhile, for the sake of phase information collection which is used in data manage and rebuild, there is a counter of phase that record the difference between trigger and Shockwave. In this way, the synchronization in the DDAS is resolved.Secondly, because of the big difference of Shockwave and bubble power signal frequency range, according to the demand of Nyquist sampling theorem, a data acquisition mode of alternative sampling-rate is designed. Using the counter of sampling pot, the speed of data acquisition is shift between high and low.Thirdly, in order to research the statistics rule of underwater explosion, the acquisition data is collected by repetitive series examination. Because the distributed test system is hardly to meet the request of acquisition data real time upload, the double memory system based on SRAM and FLASH is build. Utilize the high-speed buffer ability of SRAM, the acquisition data is being write and read. And make use of big capability of FLASH, repetitious examination data is being saved, and the request of data acquisition is meet in this way.Making use of AVR single machine and programmable logic device realized the controlling of data gathering circuit, the data gathering controlling circuit design for automated triggering with double delay shift rate. Test outcome of each functional module is compliance with the data gathering demand in xx pressure field.