Buried Metal Pipeline Voltage Signal Measurement System Design And Implementation

At present,the transportation of oil,natural gas and other energy sources is mainly based on buried metal pipelines.Due to the complex geographical environment of the pipeline,the pipeline is affected by the environment and stray current,which is easily corroded and causes problems such as pipeline leakage.In order to maintain the health of the pipeline,the method of combining the anticorrosive coatings with the cathodic protection and the way of detecting the pipeline voltage signal are used to know the protection of the pipeline.However,there are problems such as low detection efficiency,large error and high cost.Therefore,this paper designs a voltage signal measurement system for buried metal oil pipelines.The system has the characteristics of high measurement accuracy,long battery life,real-time data interaction and diversified working modes.In order to improve the stability and reliability of the measurement system,the functions of Communication exception handling,offline storage,system status monitoring,etc.are designed and the measures and methods of system anti-interference are proposed.The innovations of this paper are as follows: Firstly,aiming at the problem that the measurement error is too large due to the change of ambient temperature,a measurement error compensation method based on regression analysis is proposed.Secondly,in order to improve the calibration efficiency and measurement accuracy of the system,a system adaptive calibration method is proposed.The main research work completed in this paper is as follows:1.Complete the design of the system hardware circuit.According to the chip power consumption requirements of the system,the switching power supply and the linear regulator chip are used for power supply design,which reduces the influence of power supply noise on the measurement accuracy.The high-precision amplifier,the clamp protection and the resistor divider circuit constitute a signal conditioning circuit,which satisfies the requirement for measuring the large dynamic range voltage signal.The SIM808 chip is used to design the communication module,which realizes the data interaction between the measurement sensor and the server.At the same time,the data storage and temperature and humidity measurement circuits were designed and the PCB design of the system hardware was completed.Test the hardware function of the system,and the test results prove that the hardware function of the system is reliable..2.Complete system software function design.In the Keil development environment,modular programming ideas are used to complete block design such as core control programs,GPRS communication programs,signal measurement programs,and data storage programs.Aiming at the problem that the network connection is easily affected by the environment,a communication exception handling program combining delay processing and watchdog reset is designed,and the communication abnormality processing makes the network connection more reliable.The offline data storage program with recyclable storage is designed.The data storage mode of the circular queue provides guarantee for off-line measurement and improves the stability of the system.The signal acquisition function,communication exception handling function and offline data storage function are tested.The test results prove the correctness of the software function of the system.3.Complete system modeling test and modeling analysis of measurement error.Aiming at the problem that the inherent noise of the system affects the measurement accuracy,a software difference compensation method is proposed.Aiming at the problem that the measurement error is too large due to the change of ambient temperature,a measurement error compensation method based on regression analysis is proposed.Firstly,a mathematical model is established for the measurement error affected by temperature,and then the measurement error is compensated by curve fitting based on ridge regression.Finally,the rationality and generalization ability of the regression model are verified.At the same time,in order to improve the measurement accuracy of the system and the calibration efficiency of the measurement sensor,a system adaptive calibration method is proposed.