As an important equipment in the fully mechanized mining face, the pose detection of the coal mining machine is a key technology for achieving automatic coal cutting. The prerequisite for realizing technologies such as "three machines" linkage and memory cutting in the fully mechanized mining face is the determination of the position and operating posture of the coal mining machine. The current research and use of gear counting, infrared radiation and other methods for detecting the pose of coal mining machines cannot determine the pose of coal mining machines in real-time in the three-dimensional direction. This article uses the Huilian Technology fiber optic combination inertial navigation system to detect the position and operating posture of the coal mining machine, and explains the application of the Huilian Technology fiber optic combination inertial navigation system on the coal mining machine. By analyzing the cutting process and factors affecting the posture of the coal mining machine, the posture of the coal mining machine is determined to be three-dimensional positioning. Based on the analysis of the basic principles of the Huilian Technology fiber optic combination inertial navigation system, the application principle of the Huilian Technology fiber optic combination inertial navigation system in coal mining machine posture detection is explained. A study was conducted on how to apply the data collected by inertial components to solve the pose of a coal mining machine. Based on the definition of the coordinate system, the update algorithm of the pose matrix was simulated and compared. The fourth-order Runge Kutta method was determined to be suitable for solving the dynamic pose angle of the coal mining machine. The basic equation for solving the pose of the coal mining machine and the initial alignment method of the Huilian Technology fiber optic combination inertial navigation system on the coal mining machine were given; Calculate the dynamic attitude angle, velocity, and position of the coal mining machine, simulate the motion trajectory of the coal mining machine using MATLAB, calculate the output of the inertial element as the input for the pose algorithm simulation, and simulate the pose algorithm of the coal mining machine; Build a simple simulation test bench for experimental verification, use a small car to simulate the movement of a coal mining machine on a flexible track, collect inertial element measurement data for pose calculation, measure the actual motion trajectory and attitude angle data of the small car at key nodes, fit the curve with the calculated data, and compare it with the curve obtained from the calculation data. The simulation and experimental results show that the Huilian Technology fiber optic combination inertial navigation system can be used to calculate the position and operating posture of coal mining machines.
Application of coal mining machine posture
In the coal mining face, it is necessary to have a clear understanding of the detailed layout of the underground working face and the entire process of the movement of the coal mining machine during coal cutting
Only then can the position and operating posture of the coal mining machine be analyzed. The drum shearer, hydraulic support, and flexible scraper conveyor are the main working equipment in the underground working face of the mine. The coal mining machine, hydraulic support, and scraper conveyor are mutually constrained in the direction parallel to the coal wall. Under the protection of hydraulic supports, the coal mining machine relies on sliding shoes to ride on the scraper conveyor to complete the coal cutting action. In the direction perpendicular to the working face, it relies on the push of the scraper conveyor to complete the forward movement action. The schematic diagram of the three machines working in the fully mechanized mining face is shown below:
Figure 1 Schematic diagram of three machines working on the working face of the coal mining machine
The coal mining machine is the main equipment for cutting and loading coal in the coal mining face. In the process of comprehensive mechanization of coal mining, the main technology to solve the problems of automatic coal cutting of the coal mining machine and automatic movement of the hydraulic support is to monitor the working posture and position of the coal mining machine on the working face, and achieve accurate and high-speed positioning and navigation of the coal mining machine. When the coal cutting position and posture of the coal mining machine can be determined, the hydraulic support can timely push and slide support based on the current position information of the coal mining machine, realizing the collaborative automation of the three machines. As shown in Figure 1, when the coal mining machine is cutting coal on the scraper conveyor, the hydraulic support supports the coal wall and roof. When the coal mining machine is cutting coal from left to right, at a distance of D from the tail of the coal mining machine, the hydraulic support begins to move the middle groove, but the value of D needs to be determined based on the current position of the coal mining machine. So the follow-up automation of the support is determined by the positioning of the coal mining machine, and the scraper pushing the middle groove is directly connected to the hydraulic support. Therefore, the key technology for the collaborative automation control of the three machines in the coal mining face is the positioning of the coal mining machine.
The automation control of the coal mining machine is the key and difficult point to achieve the automation of the coal mining face, and the key to the automation of the coal mining machine is the automatic adjustment of the drum height. There is a significant gap in the automation level of coal mining machines both domestically and internationally in terms of drum height adjustment technology, mainly manifested in the detection technology for the operating posture and position of coal mining machines.
In the fully mechanized mining face, the detection of the posture of the coal mining machine is based on the premise and foundation of the machine's memory cutting and adaptive cutting
On the basis of this, the coal mining machine is equipped with position sensors, cylinder stroke sensors, and other sensors. The driver operates the coal mining machine to cut a knife first according to the ups and downs of the coal seam. Each sensor records the corresponding motion information, which is then stored in the computer. The coal mining machine can be controlled to adjust the height based on the memory. The position and attitude parameters of the coal mining machine are important information for adaptive cutting, which directly affects the control effect of the coal mining machine.
Application of Fiber Optic Integrated Inertial Navigation System in Coal Mining Machine
Applying the fiber optic combined inertial navigation system to the coal mining machine to detect its position and attitude is actually using inertial elements (three-axis gyroscope and accelerometer) to detect the angular velocity of the coal mining machine relative to the inertial space and the specific force of the three axes of the coal mining machine, and calculate the pose information of the coal mining machine.
The inertial navigation system composed of three-axis gyroscope and three-axis accelerometer is directly installed on the coal mining machine. Because the position and operating posture of the coal mining machine are three-dimensional, their sensitive axes need to be placed perpendicular to each other to form a three-dimensional coordinate system. The angular velocities of the three axes of the coal mining machine can be sensed by a three-axis gyroscope, and this information can be transmitted to the computer to calculate the attitude matrix of the fiber optic combined inertial navigation system. Then, the acceleration information (specific force) of the coal mining machine along the axis of the body coordinate system measured by the three-axis accelerometer is transformed into the navigation coordinate system of the system using the attitude matrix, and then navigation calculation is performed. At the same time, extract the attitude angle and heading information of the coal mining machine from the attitude matrix. As can be seen from the above, in the fiber optic combined inertial navigation system, the fiber optic combined inertial navigation system completely replaces the role of the platform in the platform system, using a "mathematical platform", greatly reducing costs.
