Study On Disaster Monitoring Technology Based On High Precision Time Interval Measurement Method

With the continuous development of our country’s economy,all kinds of the project scale have been expanded.Because of the influence of local climate and environment,every place of the geological conditions is different,and some places have more complicated geological conditions,keeping track of slope displacement is an important content of safety monitoring.Only to warning the occurrence of disaster early,can we avoid damage and loss in people’s lives and property at the most extent.In the 21 st century,the rapid development of information technology for slope monitoring,data acquisition,data storage and data transmission become more convenient and quick.Accurately measure the change of time interval is the basis of the early warning of tiny displacement of slope deformation,in research of this thesis is a kind of disaster monitoring technology based on high precision time interval measurement method.This thesis refers to the basis of all kinds of slope disaster monitoring technology,put forward a kind of high precision,long distance and low cost of slope disaster monitoring technology in real time.Using German ACAM company time to digital conversion chip TDC GP22 as the core chip of the time interval measurement system,the single time interval measurement accuracy of TDC_GP22 is up to 90 ps.And we select the ISSI company SRAM chips as measure frequency statistics data cache chip,then choose the Cypress company’s USB chip CY7C68013 A as the USB interface chip to complete USB communicating with PC.In the aspect of main controller,we choosing the Altera company Cyclone II series of the EP2C5Q208C8 as the core main controller,it has lots of characteristic,for example,cost is low,the logic resources are rich and fast data processing etc.It completes configure registers of TDC_GP22,controls reading and writing timing of data caching SRAM chips,and sequential control of USB interface chip.In the design of PC software,we use LabVIEW to accomplish the design of PC interface,and it can complete effective screening of the measurement data and subsequent processing.This thesis presents an algorithm of processing data,rejecting the abnormal error firstly,according to the data statistics of frequency to calculate weighted average value of data,it will further improve the measurement precision of time interval effectively.By using FPGA to produce pulse signal source with high precision for the accuracy test of the time interval measurement system,and the experiment verified the effectiveness of the algorithm.Experiment indicates that this system has the characteristics of informatization,long distance and high precision in the aspect of slope disaster monitoring.