Research On Shearer Positioning System Based On Embedded WEB Server

In recent years,China’s coal industry has been continuously developing towards safety,efficiency,and green.The intellectualization of fully mechanized mining equipment and the automation of working faces are the development trend to achieve intelligent unmanned coal mining.As a part of fully mechanized mining equipment,coal cutters undertake the important task of cutting coal walls.The scraper conveyor provides the running track for the shearer,and the hydraulic support provides the cutting space,all of which are centered on the shearer.Therefore,the research on the positioning technology of the shearer is of great significance.For a system composed of three fully mechanized mining machines,automatic control and remote monitoring functions can significantly improve efficiency.However,current research on the system still has significant limitations in task processing architecture and data transmission methods.Aiming at the above problems,a coal mining machine positioning system based on embedded WEB server was designed and developed using Ethernet technology.The main work and conclusions of this article are as follows:(1)Aiming at the underground working face,the functional requirements of the shearer positioning system are analyzed,and the component selection and hardware design scheme of the shearer are determined.The hardware structure consists of three parts: positioning equipment,central processing unit and power supply.The power supply part ensures the stabilized current and provides the reserve power supply for the system.The central processing unit,as the core computing unit,calculates the data and provides the remote access capability for the WEB server.The positioning equipment part collects the position and attitude information of the coal cutter in real time,and establishes the serial port connection with the external equipment.The software architecture consists of three parts: WEB server,WEB browser and other functional programs.The WEB server has a built-in database,which has the ability to provide WEB services.The WEB browser is used as the user interface,and other functional programs are mainly used to control the automatic control of fully mechanized mining equipment.For the problems of small temporary memory and large data storage,the browser is used to download to the local disk.(2)The business logic framework of the WEB server is designed,and the data table distribution structure of the database is defined according to the parameter characteristics.The program execution flow is defined for the functions of the server software module.The functional requirements of the system web page are analyzed,and the graphic interface generation module and database communication module are designed respectively,and the data display scheme and data interaction mode are provided.AJAX technology is applied to improve the communication efficiency between browser and server.(3)The shaft encoder is used as an external auxiliary equipment in combination with the inertial navigation system as a positioning method for the shearer.Through the analysis of the dead reckoning algorithm,the parameter that affects the positioning accuracy of the shearer is determined as the attitude angle drift error of inertial navigation.Based on the classical zero speed correction model and the addition of a backward filtering process,a backward smoothing model based on Kalman filtering is established for the motion analysis of shearers.The platform misalignment angles in the east,north,and sky directions are taken as initial state variables,and the velocities in the advancing direction and vertical direction of the working surface output from inertial navigation are measured as initial variables.After obtaining the state quantity of the next moment,the new attitude angle error is measured as a quantity,and the initial state quantity is introduced for reverse iteration to obtain the state quantity of the previous moment.Filter the state quantity of the previous moment again to obtain the final result value.The simulation model is established and the inertial navigation error parameters to be set are determined through static error tests.A simple simulation experiment was conducted to verify that the simulation setting parameters meet the actual situation,and the effectiveness of the backward smoothing algorithm based on Kalman filtering for improving the accuracy of inertial navigation positioning was verified.(4)The experimental device of shearer positioning system is built,and the WEB terminal system performance test and algorithm positioning accuracy test are designed for the positioning system.The operation of the image display and page jump function of the WEB page is tested,and the communication between the WEB page and the database is normal.Using the GPS-RTK station trajectory as a reference,two ground tests were conducted.In the 300 meter ground test,the probability error of the first cutting ball was 0.1298 m.The probability error of the second cutting ball is 0.1789 m,Compared to the previous algorithm,the accuracy has improved by about 36%.