Wear Measurement Of Scraper Conveyor Sprocket Tooth Based On Shape From Focused

Under the background of the upgrading of global industrial manufacturing industry,the layout of "made in China 2025" has been put forward in China.At this stage,China is in a rapid transformation from "made in China" to "Chinese Smart Manufacturing".As a result,mechanical equipment is also developing towards the direction of intelligent and automatic control.The underground comprehensive mining equipment with automatic control will gradually replace the employees engaged in traditional operation.Scraper conveyor is one of the modern equipment for mining coal mines.It has three main purposes: conveying coal,providing moving tracks for shearers and providing forward pivots for hydraulic supports.Therefore,its working status directly affects the safety and production efficiency of modern coal mines.The chain transmission structure part is the most important part of the scraper conveyor,and the sprocket is the key part of this part,so its performance directly affects the comprehensive index of the scraper conveyor.Friction caused by sprocket in direct contact with chain will cause wear.Severe wear is the main form of a sprocket failure and the main reason for the failure of a scraper conveyor.Due to the untimely measurement,the sprocket teeth will be severely worn.If the sprocket is not replaced in time,it will lead to off-chain when the chain of scraper conveyor is meshed with the teeth.At the same time,there is a risk of fracture of the sprocket tooth and even a safety accident,which seriously affects the production safety of the coal mine.Therefore,it is of great significance to carry out wear analysis and research on it.Based on the principle of shape from focus,a new method of wear measuring of scraper conveyor sprocket tooth is proposed in this paper,and a hardware device for collecting the sequence image of sprocket tooth is designed.In addition,this paper studies the principle and key technologies of shape from focus in detail,compares and selects the common filtering methods and focusing evaluation functions.Then,the software system of wear measurement is developed by combining the algorithms of the key technologies in the process of shape from focus.Finally,the accuracy of the measurement method is tested by reverse engineering.Firstly,the chain and sprocket of scraper conveyor are analyzed and studied to confirm failure forms and failure position.Secondly,the overall scheme of wear measurement device is designed and optimized according to the existing tooth measurement methods and technical means.Thirdly,according to the sprocket design standards,the size and structure of each component in the wear measurement device are designed,ANSYS software is used to analyze the parts and optimize their structure.Finally,the control program is compiled and integrated into PLC to realize the expected movement,as a result,the design of the wear measurement device is finished.By comparing and selecting the algorithm of the key technology in the process of shape from focus,the system framework is designed with a simple and easy to understand programming language,the function modules are constructed and the wear measurement software system is developed.The hardware device is used to collect the sprocket tooth sequence image.Then the image is read in the system;the parameters are set to realize the 3D shape reconstruction of the sprocket tooth.Finally,the volume and wear of the reconstructed model are calculated.This method can provide accurate and efficient measurement methods for measuring the tooth wear of the sprocket wheels of the scraper conveyor.The measurement accuracy of the proposed algorithm is tested by reverse engineering technology.The reconstructed 3D solid model is overlapped with the center of the original model gravity and Boolean operation is performed to obtain the common entity of the overlapped part.The volume difference between the reconstructed model and the original model and the public entity are calculated separately,and the sum of the two volume differences is compared with the volume of the original model,then the restoration accuracy of this method is obtained.The test results show that the measurement method adopted in this paper has an accuracy of more than 97.23%.