Design And Implementation Of Intensive Acquisition System For Pipeline Pressure Data

Pipeline transport is related to the lifeblood of the national economy,which plays an important role for the economic development of our country.However,the leakage of pipelines not only cause environmental pollution and economic losses,but also endanger the life safety of the people.Therefore,real-time leak detection of the pipes is of great importance,but the key of the leak detection is the acquisition of pipeline operation parameters.At present,the data acquisition system used in pipeline leak detection is larger and inconvenient to install.And it has higher cost and doesn't have the function of wireless data transmission and storage.So,it is very important to design a data acquisition system with low cost,small size,wireless transmission and data storage function.In view of the shortcomings of the existing data acquisition system,the innovation work done in this thesis is as follows:Firstly,this thesis designs a kind of intensive data acquisition system based on the miniaturization design.The designed system has the characteristics of small size,high integration,and perfect function.In the aspect of data transmission,data acquisition system not only supports the cable transmission,but also supports WIFI wireless transmission mode,and solves the data transmission problem that the field does not meet the wired communication condition.Using the SD card to store data is proposed to solve the problem of data storage,and in order to increase the storage capacity of data,LZ77 data compression algorithm is designed.Secondly,aiming at the problem of low efficiency of the existing data acquisition system by interrupt trigger,a multi task management software design based on uC/OS-? is proposed.The scheduling policy cuts and transplants the uC/OS-III operating system based on the hardware resource of STM32.The uC/OS-III operating system manages data collection,storage,transmission and time calibration with GPS,which improves the efficiency of resource utilizaton and system operation obviously.Thirdly,aiming at the problem that the sampling precision of the existing data acquisition system can not be flexibly configured,this thesis adopts the over sampling algorithm to solve this problem in the software design.Over sampling algorithm can improve the sampling accuracy and reduce the band noise power.The sampling accuracy can be flexibly configurated wtihout changing the hardware circuit design and the different sampling accuracy requirement can be meeted.Thus,the algorithm reduces the hardware cost to some extent.Finally,aiming at the problem of noise interference in the signal,the design scheme of the two filter is proposed.The first time filters the noise in the signal by the second-order low-pass filter degined in the signal conditioning circuit,the second time filters the noise by FIR filter designed in software.After two times of hardware and software filtering,the noise signal can be effectively filtered out.