Research On Real-Time Tracking And Locating Method For Pipeline Internal Detector Based On The Prediction Of Chaos

As one of the most widely used energy,Oil has become the economic lifeline of each country.Pipeline transport is the main means of oil transportation,but because of the bad working conditions or vandalism,there will be some deterioration such as corrosion in the oil pipelines that have been used for a long term,thus leading to the decrease of pipeline safety.Pipeline detector is an important kind of equipment that is designed aiming at testing the pipeline defects and predicting the lifespan of the pipe,whose appearance provides the possibility to know about the status of the pipeline and then take corresponding measures.As there are some special positions such as deformations or tee joints along the pipe and there may be deposit in the long-time-used pipe,the walking detector is vulnerable to be stuck in the pipe.The blocking detector would easily affect the oil transportation and even cause the accident of condensation as well as the pipeline wrecking.Therefore,it is extremely significant to research tracking and location technology for PIG.This thesis analysed several methods based on different theory for tracking and locating the detector,these methods are ordinary and suitable,but they are all not able to show the precise location of the detector at anytime.According to the method of locating the leakage point of the pipeline based on negative pressure wave theory,this thesis proposes a method of real-time tracking and locating the detector based on a motorless pressure wave generator and the theory of prediction of chaos,designs relative algorithom and conducts some experiments to demonstrate the effectiveness.This thesis has done several aspects of researches as follows:Firstly,this thesis introduces the negative pressure wave locating theory that has been used widely in locating the leakage point of a pipeline,proposes to apply this theory to locating he pipeline detector,studies and refines the velocity of the pressure wave,analyzes the factors that affect the accuracy of positioning and proposes the method to improve the positioning accuracy.Secondly,studies and designs the hardware of the real-time tracking and locating system of the pipeline detector based on the pressure wave theory,designs the mechanical structure of the motorless pressure wave generator,analyzes the motion state and parameters of the device in detail,designs and realizes the data acquisition system.Last but not the least,analyzes and processes the data acquired from the data acquisition system and this part is going to solve two problems which includs detecting and matching the signal.On one hand,according to the chaos property of the oil in the pipeline,proposes to apply the method of chaos prediction to the detection of the weak pressure signal,studies the algorithm to detect the weak signal of the pipeline oil,and applyies this algorithm to the experimental data after pre-processing;On the other hand,proposed to apply the method of neural network pattern classification to solving the matching problem,proposes and studies the multiple matching method,studies how to select the characteristic parameter of the weak pressure wave,designs the single match classifier and multiple match classifier based on neural network pattern classification and proposes the compound match method.