Research On Multi-information Detection And Processing Technology Of Underground Pipeline Detector

In recent years,underground pipelines have become an important part of the normal operation of the city,and regular inspections can prevent various problems caused by underground pipelines.At present,the commonly used pipeline position detection methods include in-line detection methods such as electromagnetic method and seismic wave method.However,these methods are limited by factors such as disordered pipeline distribution,complicated geological conditions,and susceptible to interference of electromagnetic fields,resulting in large errors in measurement results.In this paper,a new type of laser spot-based pipe deflection and position detection structure is designed.The position of the pipeline is reflected by the position of the spot on the imaging screen by the laser obliquely.The right angle coordinate system of the spot is determined by five small ellipse around the imaging screen.Due to the collimation of the laser,the pipeline position detected by this method has high precision and good real-time performance.The system uses two embedded Linux development boards as the data processing center and control center of the whole system.The camera is driven to capture the laser spot image and sent to the image processing module to extract the coordinates of the laser spot.The image processing module first uses the Zhang’s calibration method to calibrate the camera.Secondly,the spot image is grayed,adaptive median filtering,and eroded to obtain the preprocessed image.Then the preprocessed image is processed in two steps,one step is through threshold segmentation,contour extraction filter,small ellipse positioning to obtain the position of the spot of five small ellipse,so as to determine the given Cartesian coordinate system,the other step through the threshold segmentation,contour extraction,spot center positioning to get the position of the center of the spot,and finally the center position of the spot Converted to coordinates in a given Cartesian coordinate system by coordinate system transformation.Finally,this paper proposes a pipeline reconstruction algorithm,which uses a series of coordinates of measured points,combined with three-axis accelerometer and gyroscope data to derive the spatial coordinate system of all measurement points in the first measurement point and then reconstruct the spatial distribution of the underground pipeline.