Coal machine positioning method based on UWB

Abstract

The invention discloses a UWB-based coal machine positioning method. The method comprises the following steps: S1, setting a hydraulic support (7); s2, performing communication for the first time; s3, carrying out second communication; s4, data arrangement; s5, adjusting the number of reserved data of the distance x; s6, calculating a distance average value c; s7, the distance L between the coal machine (1) and the hydraulic support (7) is calculated; and S8, positioning the coal machine (1). According to the UWB-based coal machine positioning method provided by the invention, the problems that the coal machine is inaccurate in positioning and is influenced by the environment are solved, so that accurate positioning of the coal machine is realized.

Description

Technical Field

[0001] The present invention relates to the field of underground coal mining, and in particular to a coal mining machine positioning method based on UWB. Background Art

[0002] Coal remains a vital component of the global energy landscape, playing an indispensable role in economic development, energy security, technological innovation and industrial upgrading, job creation and regional prosperity, as well as efficient resource utilization and sustainable development. The integration of automation and intelligent technologies has revolutionized the coal mining industry, significantly accelerating the mining process, improving operational efficiency, and significantly enhancing safety. Against this backdrop, high-precision and reliable coal mining machinery positioning has become a key element in achieving this goal. It not only ensures precise execution of mining operations but also further guarantees the efficiency and safety of the entire mining process.

[0003] Defects and shortcomings of existing technology:

[0004] Coal machine encoder positioning: As a built-in device of the coal machine, the coal machine encoder is convenient, but as the travel distance of the coal machine increases, the error will gradually accumulate, especially when the encoder slips, which will lead to deviation in the coal machine position information.

[0005] Infrared positioning: The infrared signal system requires an additional infrared receiver installed on each bracket and an infrared transmitter installed on the coal mining machine. The infrared receiver receives the signal from the infrared transmitter and calculates the coal mining machine's position. However, this system is susceptible to interference from smoke and dust generated during coal cutting. In severe cases, signal transmission may be completely blocked, affecting the coal mining machine's positioning accuracy.

[0006] Application number CN202410323384.4 discloses a vision-based coal mining machine positioning auxiliary correction method, which relates to the field of underground coal mining and includes the following steps: S1, obtaining the position information of the coal mining machine positioned by the infrared sensor and shaft encoder on the coal mining machine; S2, using the cameras distributed on the working face as position correction points, using a visual method to obtain the accurate position of the coal mining machine;

[0007] S3. Use the coal mining machine position obtained in S2 to perform initialization position correction on the shaft encoder; S4. Perform weighted fusion on the confidence of the above-obtained infrared position of the coal mining machine and the shaft encoder position to obtain the accurate position of the coal mining machine. Summary of the Invention

[0008] The present invention aims to overcome the technical problem of inaccurate positioning of coal mining machinery in coal mine working faces in the prior art, and provides a coal mining machinery positioning method based on UWB, which solves the problem of inaccurate positioning of coal mining machinery and the influence of the environment, thereby realizing accurate positioning of coal mining machinery.

[0009] The present invention provides a coal mining machine positioning method based on UWB, comprising the following steps:

[0010] S1. Hydraulic support installation: Several hydraulic supports are installed according to the coal mining environment of the working face in the mine. UWB base station devices, electro-hydraulic controllers and stroke sensors are installed on the hydraulic supports.

[0011] S2. First communication: The UWB coal machine tag installed on the coal machine is used as the signal sending end, and the UWB base station device is used as the signal responding end. The UWB coal machine tag communicates with the UWB base station devices installed on all hydraulic supports to obtain the distance x between the UWB coal machine tag and the UWB base station device, and calculates the minimum value m of the distance x;

[0012] S3. Second communication: The UWB coal machine tag performs secondary communication with the UWB base station device at a distance x between [m, 2m]. The electro-hydraulic control controller records the distance x sent by the UWB base station device on the corresponding hydraulic support and the travel data b sent by the travel sensor;

[0013] S4. Data collation: The electro-hydraulic control server collects the distance x and stroke data b sent by each electro-hydraulic control controller. When the electro-hydraulic control server receives the distance x and stroke data b sent by the same electro-hydraulic control controller, it replaces the previously received distance x and stroke data b sent by the same electro-hydraulic control controller with the data.

[0014] S5. Adjustment of the number of retained data for distance x: The electro-hydraulic control server dynamically adjusts the number of retained data using a sliding average filter algorithm based on the distance x sent by the electro-hydraulic control controller;

[0015] S6. Calculate the average distance c:

[0016]

[0017] where x i is the distance between the UWB coal machine tag and the UWB base station device, w i is the distance data weight, σ i is the distance data variance;

[0018] S7. Calculate the distance L between the coal machine and the hydraulic support:

[0019]

[0020] Among them, L iis the distance between the coal machine and the i-th hydraulic support, s is the distance between two adjacent hydraulic supports, d is the distance between the ground projection of the UWB base station device and the ground projection of the UWB coal machine tag, a is the stroke sensor value when the push rod on the hydraulic support is fully pushed, b i is the travel data of the i-th hydraulic support, h is the distance between the UWB base station device and the horizontal projection of the UWB coal machine tag;

[0021] S8, coal machine positioning:

[0022] ① When L i >c and L p <c, the coal machine is positioned between the two hydraulic supports numbered i and i+1, where i and p are the numbers of the hydraulic supports, i and p are integers, 1≤i≤n, 1≤p≤n, p≠i, and n is the number of hydraulic supports;

[0023] ②When L i =L i+1 =c, set the distance threshold, when |L i -L i+1 |When the distance is greater than the threshold, the coal machine is positioned according to ①.

[0024] The UWB-based coal mining machine positioning method of the present invention, as a preferred embodiment, the first communication in step S2 and the second communication in step S3 include the following steps:

[0025] S21, the UWB coal machine tag initiates communication with the UWB base station device;

[0026] S22, the UWB base station device responds after receiving the communication information;

[0027] S23, the UWB coal machine tag responds again after receiving the reply information;

[0028] S24, the UWB base station device ends the communication after receiving the secondary reply information, the secondary reply information including the timestamp information of the UWB coal machine tag;

[0029] S25. Flight time calculation:

[0030]

[0031] Where: R a D is the displacement of the UWB coal machine tag from initiating communication to receiving reply information. a D is the displacement of the UWB coal mining machine tag from receiving the reply information to sending the second reply information; b R is the displacement of the UWB base station device from receiving communication to sending reply information. b It is the displacement from when the UWB base station device sends the reply information to when it receives the secondary reply information.

[0032] The core principle of the UWB bilateral positioning algorithm is to calculate distance using the signal flight time between two devices. In practice, the two devices exchange signals, record the timestamps of signal transmission and reception, and then calculate the signal flight time based on the timestamp data, thereby determining the distance between the devices.

[0033] In the UWB-based coal mining machine positioning method described in the present invention, as a preferred embodiment, the time interval for the same electro-hydraulic control controller to send the distance x and travel data b to the electro-hydraulic control server in step S4 is 200ms.

[0034] The UWB-based coal machine positioning method described in the present invention is, as an optimal method, a time threshold is set in the electro-hydraulic control server. When the time interval between the electro-hydraulic control server receiving the distance x and stroke data b sent by the same electro-hydraulic control controller is greater than the time threshold, it is determined that the distance x and stroke data b sent by the electro-hydraulic control controller are invalid.

[0035] The UWB-based coal machine positioning method described in the present invention has a time threshold of 1s as a preferred method. 1s as the time threshold can balance the integrity and real-time performance of the data to a certain extent. Within this time window, multiple UWB data updates can usually be received, thereby ensuring the relative integrity of the data. If the time threshold is set too short, the data may not reach the server in time due to network delays, equipment failures, etc., resulting in misjudgment; setting 1s as the time threshold can reduce the probability of such misjudgment to a certain extent.

[0036] In the UWB-based coal mining machine positioning method described in the present invention, as a preferred embodiment, the number of distance x data points retained in step S5 is 5 to 15. The number of retained data points is related to the magnitude of data fluctuations. When data fluctuations are large, the most recent 15 distance data points are retained, while when data is stable, the most recent 5 distance data points are retained.

[0037] The UWB-based coal mining machine positioning method of the present invention, as a preferred embodiment, further includes the following steps between step S6 and step S7:

[0038] S6', correction of the average distance c: linear difference compensation is performed through the average distance of adjacent hydraulic supports:

[0039]

[0040] Where i is the number of the hydraulic support.

[0041] In the UWB-based coal mining machinery positioning method described in the present invention, as a preferred embodiment, the distance threshold in step S8 is s / 30.

[0042] The present invention has the following advantages:

[0043] (1) In the present invention, since the distance Li between the coal machine and the hydraulic support changes at all times when the travel sensor changes during coal machine frame shifting, the influence of the shifting of the supports before and after the coal machine on the calculation can be avoided;

[0044] (2) The present invention is resistant to interference from coal dust and gangue in coal mines. It does not require manual operation during use and can automatically identify the position of the coal machine, providing efficient and fast coal mining for the coal mine working face. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a flow chart of a coal machine positioning method based on UWB;

[0046] Figure 2 A schematic diagram of hydraulic support setup for a coal machine positioning method based on UWB;

[0047] Figure 3 This is a flow chart of the first and second communications of a coal machine positioning method based on UWB;

[0048] Figure 4 Schematic diagram of the first and second communications of a coal machine positioning method based on UWB;

[0049] Figure 5 This is a data transmission diagram of a coal mining machinery positioning method based on UWB in Example 1;

[0050] Figure 6 Schematic diagram of calculation of the distance L of a coal mining machine positioning method based on UWB in Example 2;

[0051] Figure 7 This is a stereogram of the calculation of the spacing L of a coal machine positioning method based on UWB in Example 2;

[0052] Figure 8 This is a schematic diagram of the movement of adjacent supports in a UWB-based coal machine positioning method in Example 2;

[0053] Figure 9 This is a schematic diagram of the travel movement of the interval bracket in a UWB-based coal machine positioning method in Example 2.

[0054] Reference numerals:

[0055] 1. Coal machine; 2. UWB coal machine tag; 3. UWB base station device; 4. Electro-hydraulic control controller; 5. Electro-hydraulic control server; 6. Stroke sensor; 7. Hydraulic support. DETAILED DESCRIPTION

[0056] Example 1

[0057] like Figure 1 As shown, a coal machine positioning method based on UWB includes the following steps:

[0058] S1, hydraulic support 7 settings: Figure 2 As shown, a number of hydraulic supports 7 are set up according to the coal mining environment of the working face in the mine, and a UWB base station device 3, an electro-hydraulic controller 4 and a stroke sensor 6 are provided on the hydraulic supports 7;

[0059] S2. First communication: The UWB coal machine tag 2 installed on the coal machine 1 is used as the signal sending end, and the UWB base station device 3 is used as the signal responding end. The UWB coal machine tag 2 communicates with the UWB base station devices 3 installed on all hydraulic supports 7 to obtain the distance x between the UWB coal machine tag 2 and the UWB base station device 3, and calculates the minimum value m of the distance x;

[0060] S3, second communication: The UWB coal machine tag 2 performs secondary communication with the UWB base station device 3 at a distance x between [m, 2m]. The electro-hydraulic controller 4 records the distance x sent by the UWB base station device 3 on the corresponding hydraulic support 7 and the travel data b sent by the travel sensor 6;

[0061] like Figures 3-4 As shown, the first communication and the second communication include the following steps:

[0062] S21, UWB coal machine tag 2 initiates communication with UWB base station device 3;

[0063] S22, the UWB base station device 3 responds after receiving the communication information;

[0064] S23, UWB coal machine tag 2 receives the reply information and makes a second reply;

[0065] S24, the UWB base station device 3 ends the communication after receiving the secondary reply information, the secondary reply information including the timestamp information of the UWB coal mining machine tag 2;

[0066] S25. Flight time calculation:

[0067]

[0068] Where: R a D is the displacement of UWB coal machine tag 2 from initiating communication to receiving reply information. a D is the displacement of UWB coal mining machine tag 2 from receiving the reply information to sending the second reply information; b R is the displacement of the UWB base station device 3 from receiving communication to sending reply information. b is the displacement of the UWB base station device 3 from sending the reply information to receiving the secondary reply information;

[0069] S4. Data collation: The electro-hydraulic control server 5 collects the distance x and stroke data b sent by each electro-hydraulic control controller 4. When the electro-hydraulic control server 5 receives the distance x and stroke data b sent by the same electro-hydraulic control controller 4, it replaces the distance x and stroke data b previously received by the same electro-hydraulic control controller 4 with the distance x and stroke data b sent by the same electro-hydraulic control controller 4. The time interval between the distance x and stroke data b sent by the same electro-hydraulic control controller 4 to the electro-hydraulic control server 5 is 200ms. The electro-hydraulic control server 5 is set with a time threshold of 1s. When the time interval between the distance x and stroke data b sent by the same electro-hydraulic control controller 4 by the electro-hydraulic control server 5 is greater than the time threshold, the distance x and stroke data b sent by the electro-hydraulic control controller 4 is determined to be invalid.

[0070] S5. Adjustment of the number of distance x retained data: The electro-hydraulic control server 5 dynamically adjusts the number of retained data using a sliding average filtering algorithm based on the distance x sent by the electro-hydraulic control controller 4; the number of distance x retained data is 5 to 15, and the number of retained data is related to the size of the data fluctuation. When the data fluctuation is large, the latest 15 distance data are retained, and when the data is stable, the latest 5 distance data are retained; the data transmission process is as follows Figure 5 As shown;

[0071] S6. Calculate the average distance c:

[0072]

[0073] where x i is the distance between the UWB coal machine tag 2 and the UWB base station device 3, w i is the distance data weight, σ i is the distance data variance;

[0074] S6', correction of the average distance c: linear difference compensation is performed using the average distance between adjacent hydraulic supports 7:

[0075]

[0076] Wherein, i is the number of the hydraulic support;

[0077] S7. Calculate the distance L between the coal machine 1 and the hydraulic support 7:

[0078]

[0079] Among them, L i is the distance between the coal machine 1 and the i-th hydraulic support 7, s is the distance between two adjacent hydraulic supports 7, d is the distance between the ground projection of the UWB base station device 3 and the ground projection of the UWB coal machine tag 2, a is the value of the stroke sensor 6 when the push rod on the hydraulic support 7 is fully pushed, b i$S_i$ is the stroke data of the $i$-th hydraulic support 7, and $h$ is the distance from the UWB base station device 3 to the horizontal projection of the UWB coal miner tag 2;

[0080] S8. Positioning of the coal miner 1:

[0081] ① When $L$ i > $c$ and $L$ p < $c$, position the coal miner 1 between the two hydraulic supports 7 numbered $i$ and $i + 1$, where $i$ and $p$ are the numbers of the hydraulic supports 7, $i$ and $p$ are integers, $1\leq i\leq n$, $1\leq p\leq n$, $p\neq i$, and $n$ is the number of hydraulic supports 7;

[0082] ② When $L$ i = $L$ i+1 = $c$, set a distance threshold, and the threshold is $s / 30$. When $|L$ i -$L$ i+1 | is greater than the distance threshold, position the coal miner 1 according to ①.

[0083] Embodiment 2

[0084] As Figure 6 shown, there are 8 hydraulic supports 7 at the position where the coal miner 1 operates. When the coal miner 1 runs within the range from the left half of the support spacing $l_2$ to the right half of the support spacing $l_3$ of one of the hydraulic supports 7, it is considered that the position of the coal miner 1 is the support number of this hydraulic support 7. As Figure 7 shown,

[0085] $l_2$ 2 = $s / 2$ 2 + ($d - (a - b)$) 2

[0086]

[0087] After the electro-hydraulic control server 5 calculates $l_2$ for each hydraulic support 7, compare the $l_2$ value of each hydraulic support 7 with the average value $c$ of the UWB base station device 3 data:

[0088] ① If $l_2$ of a certain hydraulic support 7 > $c$ and $l_2$ of the remaining hydraulic supports 7 < $c$, it means that the coal miner 1 is within the range of $l_2 - l_3$ of this hydraulic support 7, then the position of the coal miner 1 is at this hydraulic support 7;

[0089] ② If the $l_2$ values of two consecutive hydraulic supports 7 are equal to $c$, it means that the coal miner 1 is at the critical point between the two hydraulic supports 7. At this time, do not calculate the position of the coal miner 1. It is necessary to set the threshold to $s / 30$. After the difference in $l_2$ between these two hydraulic supports 7 is greater than the threshold, then calculate the position of the coal miner 1 according to ①.

[0090] As Figures 8-9 shown, when the coal miner 1 moves the support, the stroke sensor 6 will change at all times, and the values of $l_2$ and $l_3$ will change accordingly.

[0091] The above description is only illustrative of the present invention and not restrictive. Those skilled in the art will understand that any modification, change or equivalent that can be made without departing from the spirit and scope defined by the claims will fall within the scope of protection of the present invention.

Claims

1. A coal mining machine positioning method based on UWB, characterized by: The following steps are involved: S1. Setting of hydraulic supports (7): a plurality of hydraulic supports are set according to the coal mining environment of the working face in the mine, and a UWB base station device (3), an electro-hydraulic controller (4) and a stroke sensor (6) are provided on the hydraulic supports (7); S2, first communication: the UWB coal machine tag (2) provided on the coal machine (1) is used as a signal transmitting end, and the UWB base station device (3) is used as a signal responding end. The UWB coal machine tag (2) communicates with all the UWB base station devices (3) provided on the hydraulic support (7) to obtain the distance x between the UWB coal machine tag (2) and the UWB base station device (3), and calculates the minimum value m of the distance x; S3, second communication: the UWB coal machine tag (2) performs secondary communication with the UWB base station device (3) whose distance x is between [m, 2m], and the electro-hydraulic control controller (4) records the distance x sent by the UWB base station device (3) on the corresponding hydraulic support (7) and the travel data b sent by the travel sensor (6); S4, data arrangement: the electro-hydraulic control server (5) collects the distance x and the travel data b sent by each electro-hydraulic control controller (4), and when the electro-hydraulic control server (5) receives the distance x and the travel data b sent by the same electro-hydraulic control controller (4), it replaces the distance x and the travel data b previously received from the same electro-hydraulic control controller (4) with the distance x and the travel data b; S5, adjustment of the number of retained data at distance x: the electro-hydraulic control server (5) dynamically adjusts the number of retained data using a sliding average filtering algorithm according to the distance x sent by the electro-hydraulic control controller (4); S6. Calculate the average distance c: where x i is the distance between the UWB coal machine tag (2) and the UWB base station device (3), w i is the distance data weight, σ i is the distance data variance; S7. Calculate the distance L between the coal machine (1) and the hydraulic support (7): Among them, L i is the distance between the coal machine (1) and the i-th hydraulic support (7), s is the distance between two adjacent hydraulic supports (7), d is the distance between the ground projection of the UWB base station device (3) and the ground projection of the UWB coal machine tag (2), a is the value of the stroke sensor (6) when the push rod on the hydraulic support (7) is fully pushed, b i is the travel data of the i-th hydraulic support (7), and h is the distance between the UWB base station device (3) and the horizontal projection of the UWB coal machine tag (2); S8. Positioning of the coal machine (1): ① When L i >c and L p <c, the coal machine (1) is positioned between the two hydraulic supports (7) numbered i and i+1, wherein i and p are numbers of the hydraulic supports (7), i and p are integers, 1≤i≤n, 1≤p≤n, p≠i, and n is the number of the hydraulic supports (7); ②When L i =L i+1 =c, set the distance threshold, when |L i -L i+1 When the distance is greater than the threshold value, the coal machine (1) is positioned according to ①.

2. The UWB-based coal mining machine positioning method according to claim 1, characterized in that: The first communication in step S2 and the second communication in step S3 include the following steps: S21, the UWB coal mining machine tag (2) initiates communication with the UWB base station device (3); S22, the UWB base station device (3) responds with information after receiving the communication information; S23, the UWB coal mining machine tag (2) makes a secondary reply after receiving the reply information; S24, the UWB base station device (3) ends the communication after receiving the secondary reply information, wherein the secondary reply information includes the timestamp information of the UWB coal mining machine tag (2); S25. Flight time calculation: Where: R a D is the displacement of the UWB coal machine tag (2) from initiating communication to receiving reply information, a D is the displacement of the UWB coal mining machine tag (2) from receiving the reply information to sending the secondary reply information; b R is the displacement of the UWB base station device (3) from receiving communication to sending reply information, b It is the displacement of the UWB base station device (3) from sending the reply information to receiving the secondary reply information.

3. The UWB-based coal mining machine positioning method according to claim 1, characterized in that: In step S4, the time interval between the distance x and the travel data b sent by the same electro-hydraulic control controller (4) to the electro-hydraulic control server (5) is 200 ms.

4. The UWB-based coal mining machine positioning method according to claim 3, characterized in that: The electro-hydraulic control server (5) is provided with a time threshold. When the time interval between the electro-hydraulic control server (5) receiving the distance x and the travel data b sent by the same electro-hydraulic control controller (4) is greater than the time threshold, the electro-hydraulic control server (5) determines that the distance x and the travel data b sent by the electro-hydraulic control controller (4) are invalid.

5. The UWB-based coal mining machine positioning method according to claim 4, characterized in that: The time threshold is 1s.

6. The UWB-based coal mining machine positioning method according to claim 5, characterized in that: In step S5, the number of data points retained at distance x is 5 to 15.

7. The UWB-based coal mining machine positioning method according to claim 1, characterized in that: The following steps are also included between step S6 and step S7: S6', correction of the distance average value c: linear difference compensation is performed through the distance average value of the adjacent hydraulic supports (7): Wherein, i is the serial number of the hydraulic support (7).

8. The UWB-based coal mining machine positioning method according to claim 1, characterized in that: The distance threshold in step S8 is s / 30.

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