Research On Intelligent Recognition System Of HDPE Film Defects Based On Thermospectral Model

The rapid economic development has driven the pace of life to accelerate,and the amount of domestic waste generated by people has also increased.As well as the gradual planning of environmental protection in villages and towns,the demand for landfills is increasing.In order to prevent landfill waste from polluting the surrounding soil environment,a complete anti-seepage system needs to be built in the landfill.At present,the main anti-seepage material of the landfill is high-density polyvinyl chloride membrane(HDPE).In the early construction stage of the landfill,the HDPE membranes are mainly connected by pressure hot-melt welding,so it is often due to the virtual reality in the welding of HDPE membranes.Factors such as welding,missing welding,and mechanical damage during operation have led to the destruction of the integrity of the HDPE film.Will damage the integrity of the HDPE film.The methods of evaluating HDPE membrane defects during the construction period are mainly divided into destructive and non-destructive evaluations.In the destructive evaluation method,pressure detection is mainly used for the weld area.This method is simple in principle and can determine the defect,but cannot determine the specific defect location.In addition,when the pressure is filled,the pressure value is not properly controlled and it is easy to affect the HDPE film weld.The area has become a potential leakage threat.Non-destructive evaluation is mainly an electrical evaluation method,but this method will cause small defects and hollow defects in the weld area to be unable to be effectively detected.In order to realize the accurate judgment of the location and size of the HDPE film defect,this thesis uses the infrared detection principle to study the defect detection of the HDPE film weld area based on the simultaneous temperature difference characteristics of the heterogeneous medium in the HDPE film defect area of the landfill.Firstly,the layout of the infrared temperature difference on the surface of the HDPE film is studied,the imaging mechanism of the infrared image of the HDPE film is analyzed,and the infrared radiation theory and the heat conduction process are analyzed in depth.When the external excitation heat source acts,the infrared image acquisition system is used to collect infrared serial images of the HDPE film,and record the temperature distribution of the defect area of different defect sizes and shapes.Then the best detection time period and the extraction of defect contours are researched,and the temperature at different locations and the change law of infrared defect areas over time are analyzed,and the temperature change curve and the best detection time period for defects are determined.On the basis of algorithm application research,according to the characteristics of infrared images,infrared image preprocessing algorithms and defect edge detection algorithms that meet the application of the system are proposed,and the contours of HDPE membrane defects are identified and extracted.Finally,the HDPE film defect contour intelligent recognition system is researched,combined with infrared detection technology to identify the HDPE film defect contour theory,and a series of related modules such as infrared image information automatic acquisition module,infrared image analysis module and defect contour recognition module are carried out.Software and hardware design.The experimental results show that preprocessing operations such as denoising and edge enhancement of the infrared images collected by the detection system can improve the edge effect of the defect contour of the final image.Based on the edge extraction of the infrared image,the position and actual size of different types of defects such as the central defect with length of 4cm and9 cm,the penetration defect of 7cm and the edge defect of 16 cm are estimated respectively,and the recognition error is 10% respectively.,5.4%,6.4% and 3.2%,the overall control is 3.2% to 10%,to achieve the purpose of locating the actual defect location and size.