Research And Development Of Pipeline Leakage Detection Synchronous Acquisition System

In recent years,a number of leakage accidents have occurred in the oil pipeline in various regions,resulting in huge economic loss and environmental pollution.In order to reduce the loss caused by pipeline leakage,a low cost and high precision GPS synchronous data acquisition system is needed.This system is mainly used for pipeline leakage detection.It provides reliable data information and synchronization time for the leakage detection algorithm,so as to locate the leakage point timely and accurately.According to the problem that the synchronous data acquisition system used by a company in Shanghai for pipeline leakage detection is not accurate in time synchronization,this thesis proposes a solution of Raspberry PI(RPi)synchronous data acquisition system based on SOPC.In this scheme,GPS time is taken as the synchronization benchmark,and a method combining software and hardware is adopted to ensure the high synchronization of remote ADC sampling time.In the hardware design using FPGA internal logic resources and integration of Nios? processor system on programmable chip,based on the system function to write custom logic module and configure the soft core processor,complete the production of high precision time,synchronization,data collection and storage,and other functions.Formulate data transmission protocol,transmit time information and ADC sampling data to RPi through SPI interface,and write test software on RPi to test system functions.Finally,the GPS synchronization accuracy test,data transmission reliability test,synchronization data synchronization accuracy test and AD acquisition test of the test system.The time accuracy of the acquisition system through the above test is 200 us,and the synchronization error with GPS is 0.1us;The effective resolution of AD acquisition board is 12 bits,and the highest conversion rate can be set to 5KSPS per channel.The maximum synchronization error between channels is 39 us.All the above indexes meet the performance requirements of the system and can provide high precision synchronous data for the leakage detection algorithm.