Research Of Wirerope Flaw Detection In Conveyor Belt

Steel core conveyor belt consists of steel core inside and colloid outside,which is widely used in the field of material transport such as coal mine,harbor,wharf and so on.However,the severe work environment and the long-term running with heavy load were always doing damage to the conveyor belt and caused wirerope joint twitch and wirerope breaking,which may distribute to accidents of industrial manufacture.So it is significant to detect the wirerope in real time.At present,the mostly used real-time detection methods are the magnetic flux leakage testing based on electro-magnetic induction and the image analysis based on X-ray imaging.The method of magnetic flux leakage testing could only get the approximate degree and rough position of the injury,and the detecting results always include noise.On the contrary,the way of X-ray imaging could not only observe the wirerope's state in the conveyor belt directly,but also expediently analyze and recognize the failure using the image processing technologies,and this method is becoming more and more popular now.The testing way of conveyor belt flaw based on X-ray imaging was studied in this paper,and the main study work include:1 Enhancement of the conveyor belt X-ray image.Effected by the working environment,the belt X-ray image usually has much noise.What's more,the edge segments of the image were darker because of the longer distance from the X-ray source and less energy gained,resulting to smaller contrast of the steel and colloid.To solve this problem,some denoising means was compared and the most appropriate one was chosen to restrain the noise,and in the same time,an improved Retinex image enhancement algorithm was proposed to strengthen the image contrast,making it more convenient for the following image processing.2 Detection of the wirerope joint twitch in the belt.Most of the current methods detecting the wirerope joint twitch were based on the match of the joint pairs,which was achieved by comparing the vertical distance of the matched joints with the standard joint distance or the vertical distance of the matched joints in the reference image.The drawback of these methods were avoided in this paper,and the joints' displacement would detected completely via reverse stretch.The experimental results shown that this method could work more effectively.3 Detection of the wirerope breakage in the belt.In this part,the X-ray image of the conveyor belt without joints and the texture in the image were studied,and several texture defect monitoring algorithms were analysed to test the wrierope breakage.Based on all of this,a method based on texture regularity was proposed to detect the wrierope' breakage,and the experiment shown that this method could distinguish the breakage of the steel rope in the belt effectively,and the detection precision reached 98.9%.