The Research Of Underground Pipeline Positioning System And Error Compensation Method

Some of the underground pipelines in China appear aging,breakage,unclear position and so on.Determining the location of the pipeline's broken point and the position of the whole pipeline are the premises for safe operation of the pipeline.At present,China has begun to apply the principle of inertial navigation in the field of space to the field of pipeline detection.Due to the special environment of the pipeline,the error of the strapdown inertial navigation system will accumulate over time.Aiming at the problem of accumulative error of inertial navigation,this thesis designs a new underground pipeline positioning system and scheme.The system uses strapdown inertial navigation principle as the main positioning method,and uses the experimental method to select the appropriate coordinate correction module to achieve the purpose of eliminating the accumulated error.The thesis introduces the hardware and software components of the system,including inertial sensor,mileage wheel module,SD card storage unit and pipeline display system.In this thesis,a series of static measurement experiments are carried out,and the static output of the gyroscope is more stable by adjusting the Kalman filter parameters.Subsequently,the dynamic data of multiple heading angles and pitch angles are measured to determine the functional relationship between the gyroscope measurement and measurement errors,so that the output data of the gyroscope has higher dynamic working accuracy.In this thesis,the path of pipeline is divided into linear segments with equal length.In order to determine the reasonable positioning interval,this thesis selects different positioning intervals to complete the straight line driving experiment,and finally determines the positioning interval to be 0.7 meters.The coordinate correction module of the system can only compensate the error of one point,but in fact,each pipeline positioning point needs error compensation.In this thesis,the error sources of the system are analyzed,and two error compensation methods are introduced,which are average method and error model method.A simulation pipeline experiment platform was built,and the location experiment was completed on the experimental platform by using the positioning system designed in this thesis.The average error compensation method and the system error model method are used to compensate the error of each positioning point.Finally,the error compensation results are analyzed to verify the feasibility of the system positioning scheme and error compensation method.