A real-time positioning system and method for a coal mining machine in a fully mechanized coal mining face based on UWB

Abstract

The application provides a UWB-based real-time positioning system and method for a coal mining machine in a fully-mechanized coal mining face, and belongs to the technical field of coal mining machine positioning; solves the problems of low positioning accuracy and susceptibility to base station movement in current UWB positioning technology for coal mining machines; and comprises a UWB positioning tag card installed on the coal mining machine, a UWB positioning base station, a stroke sensor installed at a hydraulic support push cylinder, an electro-hydraulic controller, an electro-hydraulic control server, a ring network switch and a crossheading master computer; after receiving a UWB pulse signal, the UWB positioning base station calculates the distance between the coal mining machine positioning tag card and the UWB positioning base station according to the signal transmission time, and transmits signal strength and distance information to the electro-hydraulic controller through a serial port connection; the stroke sensor detects the movement of the oil cylinder piston and converts it into an electrical signal, which is transmitted to the electro-hydraulic controller through a serial port connection; and the application is applied to real-time positioning of a coal mining machine in a fully-mechanized coal mining face.

Description

Technical Field

[0001] This invention provides a real-time positioning system and method for coal mining machines in fully mechanized mining faces based on UWB, belonging to the field of coal mining machine positioning technology. Background Technology

[0002] During coal cutting, the coal mining machine moves forward or backward along the fully mechanized mining face, requiring real-time knowledge of its relative position to enable operations such as following the machine, moving the support frame, and retracting the sidewalls. Current technologies for real-time positioning of coal mining machines in fully mechanized mining faces mainly include positioning using walking encoders and infrared sensors, but all have some shortcomings.

[0003] The positioning method using a walking encoder is susceptible to accumulated errors. In some special cases, tire slippage may occur, making it impossible to accurately measure tire rotation. Uneven ground or obstacles on the working face may also lead to inaccurate measurement results from the walking encoder. The disadvantages of infrared sensor positioning for coal mining machines are mainly reflected in the following: environmental interference factors such as dust and smoke at the coal mining site may affect the signals received by the infrared sensors; they are easily blocked by objects; and infrared sensors require straight-line propagation during detection.

[0004] Due to various shortcomings of traditional coal mining machine positioning technology, UWB (Ultra-Wide Band) technology was introduced. UWB positioning technology is a positioning technique that uses ultra-short pulse signals. UWB positioning technology has advantages such as high accuracy, strong anti-interference, and high system reliability.

[0005] Chinese invention patent (application number 202210257650.9) proposes a positioning base station and a method for personnel positioning in a fully mechanized mining face, using UWB ranging to achieve personnel positioning, but it does not mention the positioning algorithm or the selection principle of the positioning base station. Currently, due to limitations such as the layout of positioning base stations, personnel / equipment obstruction, and the selection of positioning algorithms, existing UWB positioning methods for coal mining machinery still have some shortcomings. Summary of the Invention

[0006] To address the problems of low positioning accuracy and susceptibility to base station movement in current UWB positioning technology for coal mining machines, this invention proposes a real-time positioning system and method for coal mining machines in fully mechanized mining faces based on UWB.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a real-time positioning system for a coal mining machine based on UWB in a fully mechanized mining face, including a coal mining machine UWB ranging device, a travel data acquisition device, and a positioning data transmission and calculation unit. The coal mining machine UWB ranging device includes a UWB positioning tag card installed on the coal mining machine and a UWB positioning base station installed on the hydraulic support.

[0008] The stroke data acquisition device includes a stroke sensor installed at the hydraulic support push cylinder;

[0009] The positioning data transmission and computing unit includes: an electro-hydraulic controller, an electro-hydraulic control server, a ring network switch, and a main control computer for the haulage channel;

[0010] After receiving the UWB pulse signal, the UWB positioning base station calculates the distance between the coal mining machine positioning tag and the UWB positioning base station based on the signal transmission time, and transmits the signal strength and distance information to the electro-hydraulic controller through a serial port connection.

[0011] The stroke sensor detects the movement of the cylinder piston and converts it into an electrical signal, which is then transmitted to the electro-hydraulic controller via a serial port connection.

[0012] The electro-hydraulic controller transmits the received UWB ranging information and travel data to the electro-hydraulic control server. The electro-hydraulic control server then forwards the data to the ring network switch, which transmits the data to the main control computer of the tunnel via optical fiber.

[0013] The main control computer of the roadway stores a computer program for calculating the real-time position of the coal mining machine. The real-time position calculation algorithm of the coal mining machine corrects the coordinates of the UWB positioning base station in real time based on the stroke data of the hydraulic support pushing cylinder. The real-time position calculation algorithm of the coal mining machine solves the position of the UWB positioning tag on the coal mining machine by using the least squares method.

[0014] The UWB positioning tag is installed on the body of the coal mining machine, and the UWB positioning base station is integrated into the multi-functional signal light at the top of the hydraulic support.

[0015] A real-time positioning method for a coal mining machine in a fully mechanized longwall mining face based on UWB, employing a real-time positioning system for the coal mining machine in a UWB-based longwall mining face, includes the following steps:

[0016] Step 1: The electro-hydraulic control server forwards the tag-base station distance information corresponding to the n UWB positioning base stations with the highest signal strength to the main control computer of the roadway;

[0017] Step 2: The main control computer of the roadway receives the tag-base station distance information and travel data from the travel sensor in Step 1, and uses the travel data to determine in real time whether there is a pushing / pulling action;

[0018] Step 3: Correct the coordinates of the UWB positioning base station in real time based on the travel data:

[0019] Step 3.1: The main control computer of the roadway filters the tag-base station distance information of UWB positioning base stations where the stroke of the push cylinder does not change;

[0020] Step 3.2: Combine the above n base station-tag distance coordinates to obtain a system of equations;

[0021] Step 3.3: Solve the system of equations in Step 3.2 using the least squares method to obtain the position of the UWB positioning tag card on the coal mining machine.

[0022] Step 1 specifically involves:

[0023] The UWB positioning base station monitors the UWB pulse signals sent by the UWB positioning tag card on the coal mining machine in real time, generates positioning information, and transmits the positioning information to the electro-hydraulic controller. The electro-hydraulic controller forwards the positioning information to the electro-hydraulic control server. The electro-hydraulic control server sorts the positioning information forwarded by the electro-hydraulic controller according to the signal strength, and uploads the top n data forwarded by the electro-hydraulic controller in the sorting result to the main control computer of the roadway.

[0024] The basis for determining whether there is a pushing / pulling action in real time through travel data in step 2 is as follows:

[0025] The main control computer of the roadway receives real-time data on the stroke of the push cylinder and the action data of the hydraulic support. If there is a significant change in the stroke between two consecutive records and the hydraulic support has records of pushing and pulling actions, it is determined that the stroke of the push cylinder of the hydraulic support is in the process of pushing / pulling actions.

[0026] In step 3, before correcting the base station coordinates in real time based on the travel data, a coordinate system is first established. The X-axis of the coordinate system is set as the direction of the fully mechanized mining face, the positive direction is the direction of the large frame hydraulic support, the Y-axis is the direction of the fully mechanized mining face advance, and the Z-axis is the vertical upward direction of the fully mechanized mining face.

[0027] The ranging information of the UWB positioning tag on the coal mining machine at the current moment is represented as follows:

[0028] [[x1,y1,z1,d1],[x2,y2,z2,d2],……,[x n ,y n ,z n ,d n ]];

[0029] Where x1, x2, ..., x n The X coordinates of n UWB positioning base stations are calculated based on the hydraulic support number and the width of the hydraulic support.

[0030] y1, y2……y n The Y coordinates of the n UWB positioning base stations are respectively assigned as the negative numbers of the real-time stroke value of the hydraulic support;

[0031] z1, z2...z n The coordinates of the n UWB positioning base stations Z are respectively assigned to the real-time height measurement value of the hydraulic support.

[0032] d1, d2……d n These represent the distances between n UWB positioning base stations and the UWB positioning tag on the coal mining machine.

[0033] The equation system obtained by simultaneously solving the above n base station-tag distance coordinates in step 3.2 is expressed as follows:

[0034]

[0035] The steps in step 3.3 to solve the system of equations in step 3.2 using the least squares method to obtain the position of the UWB positioning tag on the coal mining machine are as follows:

[0036] make

[0037] Performing a Taylor expansion of f(x, y, z) at the point (x0, y0, z0), we get:

[0038]

[0039] Substituting the above equation into the system of equations in step 3.2, we get:

[0040]

[0041]

[0042] ...

[0043]

[0044] In the above formula: h represents the minimum increment in the X-axis direction, k represents the minimum increment in the Y-axis direction, and m represents the minimum increment in the Z-axis direction;

[0045] Let (x0, y0, z0) be the initial values ​​of the midpoints of each UWB positioning base station. Solve the above system of equations using the least squares method to obtain h, k, and m. Then, the judgment formula... Whether it is true or not, where ε th Let (x0, y0, z0) represent any infinitesimal value. If the condition is met, the calculation stops. Otherwise, the step size of (x0, y0, z0) is increased by (h / 2, k / 2, m / 2) and then substituted into the above system of equations to recalculate until the above judgment is satisfied. The obtained (x0, y0, z0) is the coordinate of the UWB positioning tag card on the coal mining machine.

[0046] The beneficial effects of this invention compared to the prior art are as follows: The real-time positioning system and method for coal mining machines based on UWB provided by this invention can integrate the ranging information of multiple UWB positioning base stations, improve the positioning accuracy of the coal mining machine positioning tag, and at the same time, can correct the coordinates of the UWB positioning base stations in real time according to the travel sensor data, reducing the positioning error caused by the change of UWB positioning base station coordinates during the frame moving process. Attached Figure Description

[0047] The present invention will be further described below with reference to the accompanying drawings:

[0048] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0049] Figure 2 This is a flowchart of the method of the present invention;

[0050] In the diagram: 1 is a coal mining machine, 2 is a hydraulic support, 3 is a stroke sensor, 4 is a UWB positioning base station, and 5 is a UWB positioning tag. Detailed Implementation

[0051] like Figures 1 to 2 As shown, the present invention provides a real-time positioning system for a coal mining machine in a fully mechanized mining face based on UWB, including a coal mining machine UWB ranging device, a travel data acquisition device, and a positioning data transmission and calculation unit.

[0052] The coal mining machine's UWB ranging device includes a UWB positioning tag 5 and a UWB positioning base station 4. The UWB positioning tag 5 is installed on the explosion-proof casing of the coal mining machine 1, facing the hydraulic support. The UWB positioning base station 4 is integrated into the multi-functional signal light at the top of each hydraulic support 2, with one UWB positioning base station 4 installed in each multi-functional signal light at the top of each hydraulic support 2. During system operation, the UWB positioning tag 5 on the coal mining machine 1 emits UWB pulse signals at a fixed frequency. After receiving the UWB pulse signals, the UWB positioning base station 4 calculates the distance between the UWB positioning tag 5 and the UWB positioning base station 4 based on the signal transmission time, and transmits the signal strength and distance information to the electro-hydraulic controller via a serial port connection.

[0053] The stroke data acquisition device includes a stroke sensor 3 installed at the hydraulic support push cylinder. The stroke sensor 3 detects the movement of the piston of the push cylinder and converts it into an electrical signal, which is then transmitted to the electro-hydraulic controller via a serial port connection.

[0054] The positioning data transmission and calculation unit includes: an electro-hydraulic controller, an electro-hydraulic control server, a ring network switch, and a main control computer for the haulage roadway. The electro-hydraulic controller transmits the received UWB ranging information and travel data to the electro-hydraulic control server. The electro-hydraulic control server forwards the above data to the ring network switch. The ring network switch transmits the data to the main control computer for the haulage roadway via optical fiber.

[0055] The steps of the real-time positioning method for coal mining machines in fully mechanized mining faces based on UWB proposed in this invention are as follows:

[0056] Step 1: The electro-hydraulic control server forwards the location information of the n UWB base stations with the highest signal strength:

[0057] UWB positioning base station 4 monitors the UWB pulse signal sent by UWB positioning tag 5 on coal mining machine 1 in real time, generates positioning information, including tag number, signal strength, distance, etc., and transmits the above positioning information to electro-hydraulic controller. Electro-hydraulic controller forwards the above positioning information to electro-hydraulic control server. Electro-hydraulic control server sorts the positioning information forwarded by electro-hydraulic controller according to signal strength, and uploads the top n data forwarded by electro-hydraulic controller in the sorting result to the main control computer of the roadway.

[0058] Step 2: The main control computer of the roadway receives the travel data and determines in real time whether there is a pushing / pulling action:

[0059] The main control computer of the roadway receives real-time data on the stroke of the push cylinder and the action data of the hydraulic support. If there is a significant change in the stroke between two consecutive records and the support has records of pushing and pulling actions, it is determined that the stroke of the hydraulic support push cylinder is in the process of pushing / pulling action.

[0060] Step 3: Correct base station coordinates in real time based on travel data:

[0061] The first n electro-hydraulic controller forwarding data from step 1 are selected, and the electro-hydraulic controller forwarding data of the hydraulic support with changing push cylinder stroke as determined in step 2 are removed. That is, the subsequent calculated positioning information is the tag-base station distance information received by UWB positioning base station 4 when the push cylinder stroke does not change.

[0062] First, establish a coordinate system, setting the X-axis as the direction of the fully mechanized mining face, the positive direction as the direction of the large hydraulic support, the Y-axis as the direction of the fully mechanized mining face advance, and the Z-axis as the vertical upward direction of the fully mechanized mining face. Then, the ranging information of the UWB positioning tag on the coal mining machine at the current moment can be represented as [[x1,y1,z1,d1], [x2,y2,z2,d2], ..., [x...] n ,y n ,z n ,d n Where x1, x2, ..., x nThese are the X coordinates of n UWB positioning base stations, which can be calculated based on the hydraulic support number and width; y1, y2, ..., y... n These are the Y-coordinates of n UWB positioning base stations, and can be assigned the negative value of the real-time stroke of the hydraulic support; z1, z2...z n Let d1, d2, ..., dn be the Z-coordinates of n UWB positioning base stations, which can be assigned the real-time height measurement values ​​of the hydraulic support. n These represent the distances between n UWB positioning base stations and the UWB positioning tag on the coal mining machine.

[0063] Step 4: Combine the base station-tag distance coordinates to obtain equation system 1:

[0064]

[0065] Step 5: Solve the system of equations using the least squares method:

[0066] Solve system of equations 1 using the least squares method;

[0067] make

[0068] Performing a Taylor expansion of f(x, y, z) at the point (x0, y0, z0), we get:

[0069]

[0070] Substituting the above equation into equation system 1, we obtain equation system 2:

[0071]

[0072]

[0073] ...

[0074]

[0075] In the above formula: h represents the minimum increment in the X-axis direction, k represents the minimum increment in the Y-axis direction, and m represents the minimum increment in the Z-axis direction;

[0076] Let (x0, y0, z0) be the initial value of the midpoint of each UWB positioning base station. Solve the above system of equations 2 using the least squares method to obtain h, k, and m. Then, the judgment formula... Whether it is true or not, where ε th Let (x0, y0, z0) represent any infinitesimal value. If it is true, stop the calculation; otherwise, increase the step size of (x0, y0, z0) by (h / 2, k / 2, m / 2) and then substitute it into the above equation system 2 to recalculate until the above judgment formula is satisfied. The obtained (x0, y0, z0) is the coordinate of the UWB positioning tag card on the coal mining machine.

[0077] This invention corrects the positioning base station coordinates in real time based on the stroke data of the hydraulic support pushing cylinder, reducing positioning errors caused by changes in base station coordinates due to support movement. It introduces a multi-base station positioning algorithm based on the least squares method into the coal mining machine positioning, which effectively improves positioning accuracy compared to the method of selecting the two nearest base stations.

[0078] Regarding the specific structure of this invention, it should be noted that the connection relationships between the various component modules used in this invention are definite and achievable. Except as specifically described in the embodiments, their specific connection relationships can bring about corresponding technical effects and solve the technical problems proposed by this invention without relying on the execution of corresponding software programs. The models of the components, modules, and specific components appearing in this invention, the connection methods between them, and the conventional usage methods and expected technical effects brought about by the above technical features, unless specifically described, are all publicly disclosed content in patents, journal articles, technical manuals, technical dictionaries, and textbooks that can be obtained by those skilled in the art before the application date, or belong to conventional technology, common knowledge, and other existing technologies in this field. There is no need to elaborate, which makes the technical solution provided in this case clear, complete, and achievable, and can reproduce or obtain corresponding physical products based on this technical means.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A real-time positioning method for a coal mining machine in a fully mechanized mining face based on UWB, comprising a real-time positioning system for a coal mining machine based on UWB, the system including a coal mining machine UWB ranging device, a travel data acquisition device, and a positioning data transmission and calculation unit, wherein the coal mining machine UWB ranging device includes a UWB positioning tag card installed on the coal mining machine and a UWB positioning base station installed on the hydraulic support; The stroke data acquisition device includes a stroke sensor installed at the hydraulic support push cylinder; The positioning data transmission and computing unit includes: an electro-hydraulic controller, an electro-hydraulic control server, a ring network switch, and a main control computer for the haulage channel; After receiving the UWB pulse signal, the UWB positioning base station calculates the distance between the coal mining machine positioning tag and the UWB positioning base station based on the signal transmission time, and transmits the signal strength and distance information to the electro-hydraulic controller through a serial port connection. The stroke sensor detects the movement of the cylinder piston and converts it into an electrical signal, which is then transmitted to the electro-hydraulic controller via a serial port connection. The electro-hydraulic controller transmits the received UWB ranging information and travel data to the electro-hydraulic control server. The electro-hydraulic control server forwards the data to the ring network switch, and the ring network switch transmits the data to the main control computer of the roadway via optical fiber. The main control computer of the roadway stores a computer program for calculating the real-time position of the coal mining machine. The real-time position calculation algorithm of the coal mining machine corrects the coordinates of the UWB positioning base station in real time based on the stroke data of the hydraulic support pushing cylinder. The real-time position calculation algorithm of the coal mining machine solves the position of the UWB positioning tag card on the coal mining machine by using the least squares method. The method is characterized by the following steps: Step 1: The electro-hydraulic control server forwards the tag-base station distance information corresponding to the n UWB positioning base stations with the highest signal strength to the main control computer of the roadway; Step 2: The main control computer of the roadway receives the tag-base station distance information and travel data from the travel sensor in Step 1, and uses the travel data to determine in real time whether there is a pushing / pulling action; Step 3: Correct the coordinates of the UWB positioning base station in real time based on the travel data: Step 3.1: The main control computer of the roadway filters the tag-base station distance information of UWB positioning base stations where the stroke of the push cylinder does not change; Step 3.2: Solve the system of equations by combining the distance coordinates of n tags to the base station; Step 3.3: Solve the system of equations in Step 3.2 using the least squares method to obtain the position of the UWB positioning tag card on the coal mining machine.

2. The real-time positioning method for a coal mining machine in a fully mechanized longwall face based on UWB, as described in claim 1, is characterized in that: Step 1 specifically involves: The UWB positioning base station monitors the UWB pulse signals sent by the UWB positioning tag card on the coal mining machine in real time, generates positioning information, and transmits the positioning information to the electro-hydraulic controller. The electro-hydraulic controller forwards the positioning information to the electro-hydraulic control server. The electro-hydraulic control server sorts the positioning information forwarded by the electro-hydraulic controller according to the signal strength, and uploads the top n data forwarded by the electro-hydraulic controller in the sorting result to the main control computer of the roadway.

3. The real-time positioning method for a coal mining machine in a fully mechanized longwall face based on UWB, as described in claim 2, is characterized in that: The basis for determining whether there is a pushing / pulling action in real time through travel data in step 2 is as follows: The main control computer of the roadway receives real-time data on the stroke of the push cylinder and the action data of the hydraulic support. If there is a significant change in the stroke between two consecutive records and the hydraulic support has a record of pushing / pulling the support, it is determined that the stroke of the push cylinder of the hydraulic support is in the process of pushing / pulling the support.

4. The real-time positioning method for a coal mining machine in a fully mechanized longwall face based on UWB, as described in claim 3, is characterized in that: In step 3, before correcting the base station coordinates in real time based on the travel data, a coordinate system is first established. The X-axis of the coordinate system is set as the direction of the fully mechanized mining face, the positive direction is the direction of the large frame hydraulic support, the Y-axis is the direction of the fully mechanized mining face advance, and the Z-axis is the vertical upward direction of the fully mechanized mining face. The ranging information of the UWB positioning tag on the coal mining machine at the current moment is represented as follows: [[x1,y1,z1,d1],[x2,y2,z2,d2],……,[x n ,y n ,z n ,d n ]]: Where x1, x2, ..., x n The X coordinates of n UWB positioning base stations are calculated based on the hydraulic support number and the width of the hydraulic support. y1, y2……y n The Y coordinates of the n UWB positioning base stations are respectively assigned as the negative numbers of the real-time stroke value of the hydraulic support; z1, z2...z n The Z coordinates of the n UWB positioning base stations are assigned as the real-time height measurement values ​​of the hydraulic support. d1, d2……d n These represent the distances between n UWB positioning base stations and the UWB positioning tag on the coal mining machine.

5. The real-time positioning method for a coal mining machine in a fully mechanized longwall face based on UWB, as described in claim 4, is characterized in that: The equation system obtained by simultaneously solving the distance coordinates of n tags and base stations in step 3.2 is expressed as follows: 。 6. The real-time positioning method for a coal mining machine in a fully mechanized longwall face based on UWB, as described in claim 5, is characterized in that: The steps in step 3.3 to solve the system of equations in step 3.2 using the least squares method to obtain the position of the UWB positioning tag on the coal mining machine are as follows: make ; right Performing a Taylor expansion at the point (x0, y0, z0), we get: ； Substituting the above equation into the system of equations in step 3.2, we get: ； In the above formula: h represents the minimum increment in the X-axis direction, k represents the minimum increment in the Y-axis direction, and m represents the minimum increment in the Z-axis direction; Let (x0, y0, z0) be the initial values ​​of the midpoints of each UWB positioning base station. Solve the above system of equations using the least squares method to obtain h, k, and m. Then, determine the... Whether it is valid, among which Let (x0, y0, z0) represent any infinitesimal value. If it is true, stop the calculation; otherwise, increase the step size of (x0, y0, z0) by (h / 2, k / 2, m / 2) and then substitute it into the above system of equations to recalculate until the above judgment is satisfied. The obtained (x0, y0, z0) is the coordinate of the UWB positioning tag card on the coal mining machine.

7. The real-time positioning method for a coal mining machine in a fully mechanized longwall face based on UWB, as described in claim 1, is characterized in that: The UWB positioning tag is installed on the body of the coal mining machine, and the UWB positioning base station is integrated into the multi-functional signal light at the top of the hydraulic support.

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