Coal cutter positioning system and method integrating UWB-AOA-TOF positioning and infrared detection

Abstract

The invention discloses a coal cutter positioning system and method integrating UWB-AOA-TOF positioning and infrared detection. The coal cutter positioning system comprises a positioning label installed on a coal cutter and a plurality of positioning base stations installed on a support. The positioning method comprises the following steps: S1, a positioning tag on the coal mining machine sends an infrared signal and a UWB pulse signal; s2, the positioning base station receives the infrared signal and the UWB pulse signal; s3, calculating a distance value, an angle value and infrared data between the positioning label and the positioning base station, and generating a data packet; s4, transmitting the data packet to a positioning engine through a controller; s5, calculating data in the data packets of the three positioning base stations through a TOF distance positioning strategy, an AOA angle positioning strategy and an infrared positioning strategy to obtain a TOF distance positioning strategy positioning result, an AOA angle positioning strategy positioning result and an infrared positioning strategy positioning result respectively; and S6, performing comparison filtering processing by adopting a Kalman filtering algorithm to obtain a positioning label coordinate value.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining machine positioning, and in particular to a coal mining machine positioning system and method integrating UWB-AOA-TOF positioning and infrared detection. Background Art

[0002] The research background of coal mining machine positioning technology mainly involves improving the level of modern management of coal mines, reducing and preventing the occurrence of safety accidents, and improving the high yield, high efficiency and safety of coal production. With the advancement of science and technology and the development of coal mine production automation, the research on coal mining machine positioning technology has become an important means to improve coal mine production efficiency and safety. The research of this technology is not only related to the scientific and technological progress of the coal industry, but also involves the development of disciplines and the formation of research projects with independent intellectual property rights. It is of great significance to promote the informatization and automation of mines and catch up with the advanced level of world mines.

[0003] The research on coal mining machine positioning technology still faces many challenges and limitations. Traditional positioning technologies, such as infrared positioning, ultrasonic positioning, gear counting positioning and wireless positioning technology, each have their own application scenarios and advantages, but they also have their own limitations and shortcomings. For example, infrared positioning technology is greatly affected by environmental factors, such as uneven bottom plate, dust and obstruction, which may lead to unstable signal reception; ultrasonic positioning is affected by the harsh environment of coal mines and ultrasonic sound attenuation, which may lead to positioning failure; gear counting positioning method can only detect one-dimensional motion, and is affected by gear counting errors, which cannot meet the requirements of precise positioning of coal mining machines; wireless positioning technology is affected by the harsh environment of coal mines and imperfect wireless channel models, resulting in unstable positioning data.

[0004] In summary, the current single coal mining machine positioning cannot meet the anti-collision function of the coal mining machine and the hydraulic support. Through in-depth research, the present invention provides a coal mining machine positioning system and method that integrates UWB-AOA-TOF positioning and infrared detection to improve positioning accuracy, adapt to complex and changeable working environments, and solve the limitations of existing technologies. Summary of the invention

[0005] In view of the above problems, the present invention aims to provide a coal mining machine positioning system and method which integrates UWB-AOA-TOF positioning and infrared detection to improve positioning accuracy and adapt to complex environments.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A coal mining machine positioning system integrating UWB-AOA-TOF positioning and infrared detection, the coal mining machine positioning system comprising a positioning tag installed in the middle position of the coal mining machine and a positioning base station installed on a bracket; there are several positioning base stations and the several positioning base stations are arranged corresponding to several brackets arranged in sequence; the positioning tag is provided with an infrared signal transmitter and a UWB pulse signal transmitter and is used to transmit infrared signals and UWB pulse signals; the positioning base station is provided with an infrared signal receiver and a UWB pulse signal receiving antenna and is used to receive infrared signals and UWB pulse signals; at least two UWB pulse signal receiving antennas are provided.

[0008] Furthermore, the coal mining machine positioning system also includes a controller and a positioning engine; the controller is connected to the positioning base station and receives data packets transmitted by the positioning base station, the controller is connected to the positioning engine network and forwards the data packets transmitted by the positioning base station to the positioning engine, and the positioning engine calculates and determines the position of the coal mining machine based on the data packets.

[0009] A coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection is implemented by a coal mining machine positioning system integrating UWB-AOA-TOF positioning and infrared detection, and includes the following steps:

[0010] S1, the positioning tag on the coal mining machine sends infrared signals and UWB pulse signals;

[0011] S2, the positioning base station receives the infrared signal and the UWB pulse signal;

[0012] S3, the positioning base station calculates the distance value, angle value and infrared data between the positioning tag and the positioning base station according to the infrared signal and the UWB pulse signal and generates a data packet;

[0013] S4, the positioning base station transmits the data packet to the positioning engine via the controller, and the positioning engine collects at least three data packets from different positioning base stations;

[0014] S5. The positioning engine calculates the data in the three positioning base station data packets through the TOF distance positioning strategy, the AOA angle positioning strategy, and the infrared positioning strategy, and obtains the positioning results of the TOF distance positioning strategy, the AOA angle positioning strategy, and the infrared positioning strategy respectively;

[0015] S6. The positioning engine uses the Kalman filter algorithm to compare and filter the positioning results of the TOF distance positioning strategy, the AOA angle positioning strategy, and the infrared positioning strategy to obtain the optimal positioning tag coordinate value.

[0016] Furthermore, in step S3, the specific operation of the positioning base station calculating the distance value between the positioning tag and the positioning base station according to the UWB pulse signal includes the following steps:

[0017] S311, the positioning tag first sends a poll message and records the sending timestamp t0 of the poll message; next, the tag will switch to the receiving mode, wait for the reply from the positioning base station, and set a timeout limit;

[0018] S312, after receiving the poll message, the positioning base station will delay replying resp messages to the positioning tag one by one according to its own device ID; the positioning base station will record the receiving timestamp t1 of the poll message and the sending timestamp t2 of the resp message;

[0019] S313, when the positioning tag receives the resp message replied by the positioning base station, it records the receiving timestamp t3 of the resp message; then, the positioning tag aggregates the sending timestamp t0 of the poll message, the sending timestamp t4 of the final message and the receiving timestamp t3 of the resp message into the final message, and broadcasts it back to the positioning base station;

[0020] S314. After receiving the final message, the positioning base station extracts the sending timestamp t0 of the poll message and the receiving timestamp t3 of the resp message; at the same time, the positioning base station records the receiving timestamp t5 of the final message;

[0021] S315, the positioning base station starts ranging calculation after receiving all timestamps;

[0022] S316, calculate the time length T by the difference between the receiving timestamp t1 of the poll message and the sending timestamp t2 of the resp message reply1 ; The time length T is calculated by the difference between the sending timestamp t0 of the poll message and the receiving timestamp t3 of the resp message round1 ; The time length T is calculated by the difference between the receiving timestamp t3 of the resp message and the sending timestamp t4 of the final message reply2 ; The time length T is calculated by the difference between the sending timestamp t2 of the resp message and the receiving timestamp t5 of the final message round2 ;

[0023] S317, passing time length T reply1 , T round1 , T reply2 , T round2 Calculate the flight time T prop ; The calculation formula is:

[0024]

[0025] After combining the above formulas, we get:

[0026]

[0027] S318: The distance value Distance between the positioning tag and the positioning base station is calculated by the speed c of the radio wave and the flight time T. prop The calculation formula is:

[0028] Distance=T prop ×c.

[0029] Furthermore, in step S3, the specific operation of the positioning base station calculating the angle value between the positioning tag and the positioning base station according to the UWB pulse signal includes the following steps:

[0030] S321, the positioning tag transmits a UWB pulse signal, and a phase difference α occurs when the UWB pulse signal reaches two UWB pulse signal receiving antennas of the positioning base station;

[0031] S322, the positioning base station calculates the arrival angle of the UWB pulse signal by the phase difference α; the calculation formula is:

[0032]

[0033] Among them, α is the phase difference between the UWB pulse signal reaching the two UWB pulse signal receiving antennas of the positioning base station, and p is the distance difference between the positioning tag and the two UWB pulse signal receiving antennas of the positioning base station;

[0034] S323, introducing the distance d between the two UWB pulse signal receiving antennas, we get:

[0035] p = dsinθ;

[0036] S324, combining the above formulas, the arrival angle θ is obtained; the calculation formula is:

[0037]

[0038] The signal wavelength c is the speed of light, and fc is the signal frequency.

[0039] Further, in step S5, the specific steps of the positioning engine calculating the positioning result of the TOF distance positioning strategy through the TOF distance positioning strategy are:

[0040] S511, suppose that the coal mining machine positioning system has n positioning base stations, whose coordinates are (x i ,y i), and the distance from the positioning tag to the positioning base station is measured to be d i , where i is the positioning base station ID number, ranging from 0 to n;

[0041] S512, setting the coordinates of the location tag to (x, y), then for each positioning base station, we can get:

[0042]

[0043] S513, use three data packets with different positioning base station IDs to perform calculations, and construct a distance equation group with the positioning base station coordinates (x0, y0), (x1, y1), (x2, y2), the positioning tag coordinates (x, y), and the distances d0, d1, and d2 from the positioning tag to the three positioning base stations, and obtain:

[0044]

[0045] S514, eliminate the square term and obtain the resulting equation system:

[0046]

[0047] S515. Combining the above formulas, using the substitution method and the elimination method, the coordinates (x, y) of the positioning tag can be solved.

[0048] Further, in step S5, the specific steps of the positioning engine calculating the positioning result of the AOA angle positioning strategy through the AOA angle positioning strategy are:

[0049] S521, suppose that the coal mining machine positioning system has n positioning base stations, whose coordinates are (x i ,y i ), and the measured arrival angle from the positioning tag to the positioning base station is θ i , where i is the positioning base station ID number, ranging from 0 to n;

[0050] S522, setting the coordinates of the location tag to (x, y), then for each positioning base station, we can get:

[0051]

[0052] Right now:

[0053] tanθ i yx=tanθ i ·y i -x i ,i=1,2,......,n;

[0054] S523. Define a variable d to represent the measurement error, then the error equation can be expressed as:

[0055] d=hG a t;

[0056] but:

[0057]

[0058] When the variable d is 0, we get:

[0059] h=G a t;

[0060] S524, ride on both sides It can be concluded that:

[0061]

[0062] S525, ride on both sides Then we can get the matrix t, which is the coordinates of the positioning label. The calculation formula of matrix t is:

[0063]

[0064] in, is the matrix G a The transposed matrix of is a matrix The inverse matrix of .

[0065] Furthermore, in step S5, the specific operation of the positioning engine calculating the infrared positioning strategy positioning result through the infrared positioning strategy is: calculating the average value of all positioning base station IDs that receive infrared signals, and the bracket frame position corresponding to the positioning tag can be determined by the average value; the average value calculation formula of the positioning base station ID is:

[0066]

[0067] Wherein, M and N are IDs of different positioning base stations.

[0068] Furthermore, the Kalman filter algorithm continuously iterates the prediction and update process by the prediction equation and the update equation to provide the best state estimation in a noisy and uncertain environment;

[0069] The prediction equation is:

[0070]

[0071] in, is the state value of the positioning system at time t; is the optimal value of the positioning system at time t-1; F is the state transfer matrix; B is the state control matrix; u t-1 is the model correction vector; P t -is the covariance matrix; Q is the process noise;

[0072] The update equation is:

[0073]

[0074] Among them, K t is the Kalman gain; H is the measurement matrix; R is the Gaussian white noise; z t is the observed value.

[0075] Furthermore, in step S6, after the positioning engine obtains the best positioning tag coordinate value, the best positioning tag coordinate value is substituted into the tag installation position deviation compensation algorithm to calculate the bracket frame number corresponding to the center point of the coal mining machine.

[0076] Compared with the prior art, the present invention has the following advantages and positive effects:

[0077] The present invention first sends infrared signals and UWB pulse signals through the positioning tags installed on the coal mining machine, and the positioning base stations installed on each bracket receive the infrared signals, the arrival time of the UWB pulse signals and the phase difference of the UWB pulse signals arriving at the base station dual antennas, and respectively calculate the normal infrared signal, the distance from the positioning tag to the positioning base station and the AOA angle of the positioning tag at the positioning base station; then the infrared, distance and angle information of 3-5 positioning base stations are uploaded to the working face gateway through the controller, and the positioning engine of the working face gateway realizes the movement direction and accurate position of the coal mining machine through the fusion algorithm;

[0078] The present invention realizes the presence detection of coal shearer through infrared detection, that is, when infrared detection is made, it is determined that the coal shearer is nearby; then the one-dimensional coordinates of the coal shearer are accurately determined through distance measurement, that is, the position of the coal shearer on which support; finally, the direction from which the coal shearer comes is determined according to the angle; it realizes the accurate real-time positioning of the coal shearer through the fusion of multiple technologies and algorithms, solves the current problems of poor positioning accuracy of coal shearer, frame jumping, base station movement error, inability to accurately judge the coal mining direction of the coal shearer, and improves the use effect of the coal shearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0080] Figure 1 This is a layout effect diagram of positioning tags and positioning base stations;

[0081] Figure 2This is a simplified structural diagram of a positioning base station;

[0082] Figure 3 This is a simplified diagram of the structure of the positioning tag;

[0083] Figure 4 It is a timing diagram of the interaction between the positioning tag and three positioning base stations;

[0084] Figure 5 The connection layout diagram of the positioning system;

[0085] Figure 6 A diagram showing the interaction steps between the positioning tag and the positioning base station;

[0086] Figure 7 It is a layout diagram between the positioning tag and the positioning base station during distance calibration;

[0087] Figure 8 This is a diagram showing the effect of the antenna receiving signals for positioning the base station;

[0088] Fig. 9 It is a layout diagram between the positioning tag and the positioning base station during angle calibration;

[0089] Fig.10 The flowchart of the interaction between the positioning base station and the controller;

[0090] Fig.11 It is the algorithm flow chart of the positioning engine;

[0091] Fig.12 This is the fusion effect diagram of the tag base station two-dimensional positioning algorithm;

[0092] Fig.13 This is a schematic diagram of TOF positioning coordinates;

[0093] Fig.14 This is a schematic diagram of AOA positioning coordinates;

[0094] Fig.15 It is the logic diagram of infrared positioning algorithm;

[0095] Fig.16 This is a simplified diagram of the structure of the matrix data packet;

[0096] Fig.17 This is the overall flow chart of the tag base station two-dimensional positioning algorithm;

[0097] Fig.18 The following is a layout effect diagram of the brackets with increasing frame numbers from left to right;

[0098] Fig.19 This is a layout effect diagram with the bracket numbers increasing from right to left. DETAILED DESCRIPTION

[0099] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0100] The present invention discloses a coal mining machine positioning system and method integrating UWB-AOA-TOF positioning and infrared detection, so as to solve the limitations of the existing coal mining machine positioning technology, improve the positioning accuracy of the coal mining machine, and enable it to adapt to complex and changeable working environments.

[0101] 1. Overview

[0102] A coal mining machine positioning tag is installed near the middle of the coal mining machine, and a coal mining machine positioning base station is installed on the column or top beam of the bracket facing the coal mining machine. Figure 1 shown.

[0103] The overall solution sends infrared signals and UWB pulse signals through the coal mining machine positioning tag. The coal mining machine positioning base station of each bracket receives the infrared signal, the arrival time of the UWB pulse signal and the phase difference of the UWB pulse signal reaching the dual antennas of the base station, and calculates the normal infrared signal, the distance from the tag to the base station and the AOA angle of the tag at the base station respectively; the UWB communication distance between the tag and the base station is set by the transmission power to ensure that 3-5 base stations can receive the UWB pulse signal of the tag at the same time; 3-5 base stations calculate the infrared, distance and angle information, and upload it to the working face gateway through the controller. The working face gateway positioning engine realizes the movement direction and accurate position of the coal mining machine through the fusion algorithm.

[0104] 2. Hardware structure of coal mining machine positioning base station

[0105] The structure of the positioning base station is as follows: Figure 2 As shown, it is consistent with the existing infrared receiver installation structure and can achieve installation compatibility.

[0106] 3. Hardware structure of coal mining machine positioning tag

[0107] Positioning tag structure such as Figure 3 As shown, it is consistent with the existing infrared transmitter installation structure.

[0108] 4. Overall interaction process of coal mining machine positioning system

[0109] The interaction process between the coal mining machine positioning tag and the three positioning base stations is taken as an example to explain in detail. The specific timing is as follows: Figure 4 shown.

[0110] Coal mining machine positioning tags, coal mining machine positioning base stations, controllers, and gateways interact as follows Figure 5 shown.

[0111] 4.1 Interaction process between coal mining machine positioning tag and base station ranging

[0112] In UWB positioning systems, TWR (Two-Way Ranging) is a common method for measuring the distance between a tag and a base station. The TWR method estimates the distance by measuring the signal propagation time.

[0113] Below are the basic implementation steps and related algorithms of the TWR method.

[0114] DS-TWR (Dual Bidirectional Ranging): A ranging method based on UWB (Ultra Wideband) technology. The basic principle is to send and receive a series of UWB pulse signals and estimate the distance by calculating the round-trip time and the propagation speed of the signal. The main advantage of using this method is that it can reduce the influence of environmental factors such as multipath effects and signal reflections, making the distance measurement more accurate.

[0115] Figure 6 This is a diagram of the interaction steps between the coal mining machine positioning tag and the coal mining machine positioning base station, which shows the process of poll message, resp message and final message.

[0116] Figure 6 Parameter description in:

[0117] (1)TX: data transmitter.

[0118] (2)RX: data receiving end.

[0119] (3) t0, t1, t2, t3, t4, t5: timestamp.

[0120] (4)T reply1 , T round1 , T reply2 , T round2 : duration.

[0121] 4.1.1poll message, resp message, final message

[0122] Tags package and send poll messages: Tags first broadcast the poll message, and then the base station receives the message. During this process, the tag calculates and records the poll_tx_ts timestamp (equivalent to t0 above).

[0123] The base station packages and sends resp messages: After receiving the tag poll message, the base station takes out the tag ID, calculates the poll_rx_ts timestamp (equivalent to the above t1), and then replies to resp in sequence according to its own ID number.

[0124] The tag sends a final message: After receiving the resp message from the base station, the tag takes out the ID of the base station, calculates the resp_rx_ts timestamp (equivalent to t3 above), and then broadcasts the final message to all base stations. This process calculates the final_tx_ts timestamp (equivalent to t4 above).

[0125] The base station calculates the distance: The base station extracts poll_tx_ts(t0), final_tx_ts(t4), and resp_rx_ts(t3) from the final message sent by the tag. The resp_tx_ts timestamp (equivalent to t2 above) and the final_rx_ts timestamp (equivalent to t5 above) are calculated and then substituted into the DS-TWR formula for distance calculation.

[0126] 4.1.2 Ranging Interaction Process and Calculation Method

[0127] Step 1: The coal mining machine positioning tag first sends a poll message and records the timestamp of the completion of this operation (t0). Next, the tag will switch to receiving mode, wait for the reply from the coal mining machine positioning base station, and set a timeout limit.

[0128] Step 2: After receiving the poll message, the coal mining machine positioning base station will delay the reply tag one by one according to its own device ID. Each base station will record the timestamp of receiving the poll message (t1) and the timestamp of sending the resp message (t2). Then, the base station will calculate the time interval for each base station to reply based on the preset delay unit time.

[0129] Step 3: When the coal mining machine positioning tag receives the reply from the coal mining machine positioning base station in turn, it will record the timestamp (t3) of receiving the resp message from each base station. Then, the tag will summarize the sending timestamp (t0) of the poll message, the sending timestamp (t4) of the final message, and the receiving timestamp (t3) of the resp message into the final message frame, and broadcast it back to the coal mining machine positioning base station.

[0130] Step 4: After receiving the final message with a timestamp, each coal mining machine positioning base station will extract the sending timestamp of the poll message (t0) and find the receiving timestamp of the corresponding resp message (t3) according to its base station ID. At the same time, the base station will record the timestamp of receiving the final message (t5).

[0131] Step 5: After receiving all the timestamps, the coal mining machine positioning base station starts the distance measurement calculation. At this time, the total timestamps the base station has are t0, t1, t2, t3, t4, and t5.

[0132] Step 6: The tag measures 3 timestamps: t0, t3, t4, and the base station measures 3 timestamps: t1, t2, t5. The difference can be used to calculate 4 time lengths: T reply1 , T round1 , T reply2 , T round2 , then the flight time T can be calculated prop :

[0133]

[0134]

[0135] Combining formulas (1) and (2) yields the following:

[0136]

[0137] The distance can be expressed in terms of the speed of the radio wave c and the flight time T prop Multiply to get Distance:

[0138] Distance= T prop ×c (4)

[0139] 4.1.3 Distance Calibration Instructions

[0140] Take base station distance calibration as an example:

[0141] Step 1: Set the tag ID and base station ID, press Figure 7 Place as shown, and replace the base stations in sequence;

[0142] Step 2: Analyze the serial port data to get the measured distance;

[0143] Step 3: Compare the measured distance with the actual distance N m:

[0144] (1) When the measured distance is greater than the actual distance, the distance needs to be reduced, so the antenna delay is increased.

[0145] (2) When the measured distance is smaller than the actual distance, the distance needs to be increased, thus reducing the antenna delay.

[0146] Step 4: The calibration is considered successful when the difference between the actual distance and the measured distance is within plus or minus 10 cm.

[0147] Remark:

[0148] (1) Calibrate the distance by modifying the antenna delay ANT_DLY of the base station.

[0149] (2) The antenna delay value is a uint16_t data, 1 unit = 15.65ps.

[0150] 4.2 Interaction process between coal mining machine positioning tag and base station angle measurement

[0151] like Figure 8 As shown, the coal mining machine positioning tag transmits a signal, and the coal mining machine positioning base station calculates the incident angle θ through the arrival phase difference of the two antennas.

[0152] 4.2.1 Calculating the angle of arrival by phase difference

[0153] The signal transmission process of the coal mining machine positioning tag and the signal reception process of the coal mining machine positioning base station can be described as follows:

[0154] Step 1: Configure the PDOA mode of the DW3000 module to mode 3.

[0155] Step 2: The positioning tag on the coal mining machine transmits a wireless signal, which propagates in space and covers the area reaching the base station.

[0156] Step 3: The coal mining machine positioning base station is equipped with two receiving antennas, and there will be a phase difference when the signal reaches the two antennas. Since the DW3000 module has encapsulated the PDOA calculation method into the module, you only need to turn on the PDOA mode and read the corresponding register to get the phase difference α.

[0157] Step 4: The base station calculates the signal's arrival angle by measuring the phase difference between the signals received by the two antennas.

[0158] Use inverse trigonometric functions to calculate the angle:

[0159]

[0160] Among them, α is the phase difference between the coal mining machine positioning tag and the two antennas of the base station, and p is the distance difference between the coal mining machine positioning tag and the two antennas of the base station.

[0161] Because d is small and the distance between the coal mining machine positioning tag and the base station antenna is far, it can be approximated as:

[0162] p=dsinθ (6)

[0163] Combining equations (5) and (6) we can get the arrival angle θ:

[0164]

[0165] Parameter Description: Signal wavelength Where c is the speed of light and fc is the signal frequency.

[0166] 4.2.2 Angle Calibration Instructions

[0167] AOA should be 0 degrees when facing the camera, while PDOA calibration depends on the stability and accuracy of the phase difference. The following is the PDOA calibration process:

[0168] Step 1: Initialize the equipment. First, make sure the mining machine's positioning tag and base station are powered on and functioning properly. Fig. 9 shown.

[0169] Step 2: Read the serial port data of the base station through the host computer to obtain the PDOA value.

[0170] Step 3: Get 300 PDOA data points, calculate their average value, and use this average value as the PDOA deviation value. Store this deviation value in the flash memory of the base station through the serial port.

[0171] After calibration is completed, the coal mining machine's base station needs to subtract this deviation value from the original PDOA value to obtain the final phase difference.

[0172] 4.3 Infrared signal recognition

[0173] Coal mining machine positioning tag infrared transmitter:

[0174] Step 1: Signal generation, the infrared signal transmitter on the coal mining machine positioning tag emits an invisible infrared light signal through an infrared LED light.

[0175] Step 2: PWM modulation process, the infrared transmitter modulates the input electrical signal into a specific infrared light pulse sequence.

[0176] Step 3: The infrared light signal emitted by the infrared LED propagates in space. When the signal is modulated, it flashes in a specific pattern and frequency.

[0177] Coal mining machine positioning base station infrared receiver:

[0178] Step 4: The infrared receiver can receive and detect the arriving infrared light signal, and then through the photoelectric effect, the infrared light signal will be converted into an electrical signal.

[0179] Step 5: Usually the infrared receiver will detect a certain number of high and low levels. The coal mining machine positioning base station determines whether there is an infrared signal by identifying the number of high and low levels.

[0180] 4.4 Interaction process between coal mining machine positioning base station and controller

[0181] The interaction process between the coal mining machine positioning base station and the controller is as follows Fig.10As shown in the figure, when the coal mining machine positioning tag interacts with the coal mining machine positioning base station, the coal mining machine positioning base station needs to report data through the serial port. The values ​​that need to be sent to the controller are:

[0182] (1) Tag ID;

[0183] (2) Base station ID;

[0184] (3) distance value;

[0185] (4) PDOA angle value;

[0186] (5) RN serial number;

[0187] (6) Infrared data;

[0188] 4.5 Controller and Gateway Interaction Process

[0189] Step 1: The controller publishes the data reported by the coal mining machine positioning base station to the NATS message bus. The data includes tag ID, base station ID, distance value, PDOA angle value, RN serial number, and infrared data.

[0190] Step 2: The gateway's coal mining machine positioning engine service subscribes to the data and then calculates the coal mining machine's location. In this process, the controller is responsible for publishing the coal mining machine's positioning data to the NATS message bus, while the gateway's coal mining machine positioning engine service is responsible for subscribing to this data, processing it, and calculating the coal mining machine's location. This architecture takes advantage of NATS's efficient messaging capabilities to achieve data flow and processing in a distributed system.

[0191] 4.6 Coal Miner Positioning Engine Algorithm Process

[0192] like Fig.11 As shown in the figure, the coal mining machine positioning algorithm consists of two major algorithms: the tag base station two-dimensional positioning algorithm and the tag base station installation position deviation compensation algorithm.

[0193] 4.6.1 Distance, Angle, and Infrared Algorithm Model

[0194] like Fig.12 As shown in the figure, the tag base station two-dimensional positioning algorithm integrates distance, angle, and infrared data (mainly TOF, supplemented by AOA and infrared) to solve the tag coordinates.

[0195] (1) Based on TOF distance positioning algorithm

[0196] Assume that the TOF positioning system has n base stations with coordinates (x i ,y i ), and the distance from the tag to the base station is measured to be d i , where i is the base station ID number, ranging from 0 to n.

[0197] Assume the tag node coordinates are (x, y), then TOF positioning is as follows Fig.13 As shown:

[0198] Then for each base station node, we can get:

[0199]

[0200] When calculating the position of the coal mining machine positioning tag, three packets of data with different base station IDs are used for calculation. The base station coordinates are (x0, y0), (x1, y1), (x2, y2), the tag coordinates are (x, y), and the distances from the tag to the three base stations are d0, d1, and d2 respectively.

[0201] Construct the distance equation system:

[0202]

[0203] To eliminate the square terms, we can subtract the second equation from the first equation in equation (9), the third equation from the first equation, and the third equation from the second equation, and the resulting system of equations is:

[0204]

[0205] Combining formulas (9) and (10), the coordinates (x, y) of the coal mining machine positioning tag can be solved by using the substitution method and elimination method.

[0206] (2) Based on AOA angle positioning algorithm

[0207] Assume that the AOA positioning system has n base stations with coordinates (x i ,y i ), and the measured arrival angle from the tag to the base station is θ i , where i is the base station ID number, ranging from 0 to n.

[0208] Assume the label node coordinates are (x, y), then AOA positioning is as follows Fig.14 As shown:

[0209] Then for each base station node, we can get:

[0210]

[0211] Right now:

[0212] tanθ i yx=tanθ i ·y i -x i , i=1,2,......,n (12)

[0213] Since there is an error in AOA measurement, a variable d is defined to represent the measurement error, and the error equation can be expressed as:

[0214] d=hG a t (13)

[0215] According to formula (12), the variables in formula (13) are:

[0216]

[0217] When the variable d is 0, that is:

[0218] h=G a t (15)

[0219] Multiply both sides of formula (15) It can be concluded that:

[0220]

[0221] Multiply both sides of formula (16) The coordinates of the coal mining machine positioning label can be obtained as follows:

[0222]

[0223] in, is the matrix G a The transposed matrix of is a matrix The inverse matrix of .

[0224] According to formula (17), the matrix t is calculated, which is the position of the coal mining machine label coordinates.

[0225] (3) Based on infrared positioning algorithm

[0226] like Fig.15 As shown, by calculating the average value of the base station IDs of all the base stations that receive the infrared signals, the frame number position of the coal mining machine positioning tag can be determined.

[0227] The infrared positioning strategy can be obtained as follows:

[0228]

[0229] 4.6.2 Kalman Filter Algorithm

[0230] Kalman filtering is an algorithm for estimating the state of a dynamic system, especially for systems with noise and uncertainty. It provides a more accurate state estimate by recursively combining predictions and observations. The core of the Kalman filter consists of two main equations: the prediction equation and the update equation.

[0231] The prediction equation is used to predict the state at the next moment based on the current state estimate and system model. It contains two main parts: the state prediction equation and the covariance prediction equation.

[0232]

[0233] Parameter Description:

[0234] The state value of the system at time t;

[0235] The optimal value at time t-1;

[0236] F: state transfer matrix, describing the state equation model of the system;

[0237] B: state control matrix, describing the state control changes of the system;

[0238] u t-1 : Model correction vector, used to correct the established model;

[0239] P t - : Covariance matrix, which describes the direct correlation between each state quantity;

[0240] Q: process noise;

[0241] The update equation is used to combine the prediction results with the actual observation data to obtain a more accurate state estimate. It also consists of two main parts: Kalman gain calculation, state update equation and covariance update equation.

[0242]

[0243] Parameter Description:

[0244] K t : Kalman gain;

[0245] H: measurement matrix, describing the conversion relationship between measurement values ​​and state values;

[0246] R: Gaussian white noise, does not change with time;

[0247] z t : Observed values, mostly sensor measurements;

[0248] These equations work together to enable the Kalman filter to provide the best state estimate in an environment of noise and uncertainty through a continuous iterative prediction and update process.

[0249] 4.6.3 Tag Base Station 2D Positioning Algorithm

[0250] The matrix data packets collected by the positioning engine, such as Fig.16 As shown:

[0251] The overall calculation of the tag base station two-dimensional positioning algorithm is as follows: Fig.17 As shown, the process is as follows:

[0252] Step 1: The coal mining machine location engine service collects data packets from three different base stations;

[0253] Step 2: parse the data into a matrix and execute a multi-data fusion positioning algorithm (based on TOF positioning strategy, AOA positioning strategy and infrared positioning strategy);

[0254] Step 3: Fuse distance + angle + infrared positioning to select the best result, then execute the Kalman filter algorithm, and finally perform average smoothing filtering and de-extreme average smoothing filtering to filter the results and obtain the best positioning result.

[0255] Select the best positioning result description.

[0256] (1) Obtain the location of the coal mining machine positioning tag through distance.

[0257] (2) Obtain the location of the coal mining machine positioning tag through infrared.

[0258] (3) Obtain the position of the coal mining machine positioning tag through the angle.

[0259] (4) Determine whether the distance positioning is valid. If not, return; if valid, continue execution.

[0260] (5) Determine whether the difference between the infrared positioning result and the distance positioning result meets the conditions.

[0261] (6) Determine whether the difference between the angle positioning result and the distance positioning result meets the conditions.

[0262] (7) If one or more of the angle and infrared positioning conditions are met, the execution continues; otherwise, the process returns.

[0263] (8) Output distance positioning results.

[0264] Step 4: Obtain the coordinate value of the coal mining machine positioning tag, pass it to the base station tag installation position deviation compensation algorithm, and calculate the bracket frame number corresponding to the center point of the coal mining machine.

[0265] 4.6.4 Tag base station installation position deviation compensation algorithm

[0266] There are two situations, which are discussed below (the direction of offset is based on facing the coal wall).

[0267] (1) Facing the coal wall, the support frame numbers increase from left to right, such as Fig.18 As shown;

[0268] Step 1: Calculate the label offset. The shearer positioning label has a left offset and a right offset relative to the offset c of the shearer center point.

[0269] Let the label node coordinates be (x LR ,y LR ).

[0270] When offset to the left, the horizontal coordinate value is x LR1 =x LR +c.

[0271] When offset to the right, the horizontal coordinate value is x LR1 =x LR -c.

[0272] Step 2: Calculate the base station offset. The coal mining machine positioning base station has a left offset and a right offset relative to the center point of the bracket.

[0273] When the horizontal coordinate value is offset to the left

[0274] When offset to the right, the horizontal coordinate value is

[0275] Step 3: Calculate the frame number corresponding to the center point of the coal mining machine

[0276] Parameter Description:

[0277] x LR : The horizontal coordinate of the coal mining machine positioning label;

[0278] y LR : Coal mining machine positioning label ordinate;

[0279] x LR1 : Calculate the horizontal coordinate of the shearer positioning label after the left or right offset relative to the center point of the shearer;

[0280] x LR2 : Calculate the horizontal coordinate of the label after the coal mining machine positioning base station is offset to the left or right relative to the center point of the bracket;

[0281] (2) Facing the coal wall, the support numbers increase from right to left, such as Fig.19 As shown;

[0282] Step 1: Calculate the label offset. The shearer positioning label has a left offset and a right offset relative to the offset c of the shearer center point.

[0283] Let the label node coordinates be (x LR ,y LR ).

[0284] When offset to the left, the horizontal coordinate value is x RL1 =xRL -c.

[0285] When offset to the right, the horizontal coordinate value is x RL1 =x RL +c.

[0286] Step 2: Calculate the base station offset. The coal mining machine positioning base station has a left offset and a right offset relative to the center point of the bracket.

[0287] When the horizontal coordinate value is offset to the left

[0288] When offset to the right, the horizontal coordinate value is

[0289] Step 3: Set the label node coordinates to (x RL ,y RL ), calculate the frame number corresponding to the center point of the coal mining machine

[0290] Parameter Description:

[0291] x RL : The horizontal coordinate of the coal mining machine positioning label;

[0292] y RL : Coal mining machine positioning label ordinate;

[0293] x RL1 : Calculate the horizontal coordinate of the shearer positioning label after the left or right offset relative to the center point of the shearer;

[0294] x RL2 : Calculate the horizontal coordinate of the label after the coal mining machine positioning base station is offset to the left or right relative to the center point of the bracket;

[0295] The present invention first sends infrared signals and UWB pulse signals through the positioning tags installed on the coal mining machine, and the positioning base stations installed on each bracket receive the infrared signals, the arrival time of the UWB pulse signals and the phase difference of the UWB pulse signals arriving at the base station dual antennas, and respectively calculate the normal infrared signal, the distance from the positioning tag to the positioning base station and the AOA angle of the positioning tag at the positioning base station; then the infrared, distance and angle information of 3-5 positioning base stations are uploaded to the working face gateway through the controller, and the positioning engine of the working face gateway realizes the movement direction and accurate position of the coal mining machine through the fusion algorithm;

[0296] The present invention realizes the presence detection of coal shearer through infrared detection, that is, when infrared detection is made, it is determined that the coal shearer is nearby; then the one-dimensional coordinates of the coal shearer are accurately determined through distance measurement, that is, the position of the coal shearer on which support; finally, the direction from which the coal shearer comes is determined according to the angle; it realizes the accurate real-time positioning of the coal shearer through the fusion of multiple technologies and algorithms, solves the current problems of poor positioning accuracy of coal shearer, frame jumping, base station movement error, inability to accurately judge the coal mining direction of the coal shearer, and improves the use effect of the coal shearer.

Claims

1. A coal mining machine positioning system integrating UWB-AOA-TOF positioning and infrared detection, characterized in that: The coal mining machine positioning system includes a positioning tag installed in the middle position of the coal mining machine and a positioning base station installed on a bracket; there are several positioning base stations and the several positioning base stations are arranged corresponding to several brackets arranged in sequence; the positioning tag is provided with an infrared signal transmitter and a UWB pulse signal transmitter and is used to transmit infrared signals and UWB pulse signals; the positioning base station is provided with an infrared signal receiver and a UWB pulse signal receiving antenna and is used to receive infrared signals and UWB pulse signals; at least two UWB pulse signal receiving antennas are provided.

2. The coal mining machine positioning system integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 1, characterized in that: The coal mining machine positioning system also includes a controller and a positioning engine; the controller is connected to the positioning base station and receives data packets transmitted by the positioning base station, the controller is connected to the positioning engine network and forwards the data packets transmitted by the positioning base station to the positioning engine, and the positioning engine calculates and determines the position of the coal mining machine based on the data packets.

3. A coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection, which is implemented by the coal mining machine positioning system integrating UWB-AOA-TOF positioning and infrared detection according to claim 2, characterized in that: The following steps are involved: S1, the positioning tag on the coal mining machine sends infrared signals and UWB pulse signals; S2, the positioning base station receives the infrared signal and the UWB pulse signal; S3, the positioning base station calculates the distance value, angle value and infrared data between the positioning tag and the positioning base station according to the infrared signal and the UWB pulse signal and generates a data packet; S4, the positioning base station transmits the data packet to the positioning engine via the controller, and the positioning engine collects at least three data packets from different positioning base stations; S5. The positioning engine calculates the data in the data packets of the three positioning base stations through the TOF distance positioning strategy, the AOA angle positioning strategy, and the infrared positioning strategy, and obtains the positioning results of the TOF distance positioning strategy, the AOA angle positioning strategy, and the infrared positioning strategy respectively; S6. The positioning engine uses the Kalman filter algorithm to compare and filter the positioning results of the TOF distance positioning strategy, the AOA angle positioning strategy, and the infrared positioning strategy to obtain the optimal positioning tag coordinate value.

4. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 3 is characterized in that: In step S3, the specific operation of the positioning base station calculating the distance value between the positioning tag and the positioning base station according to the UWB pulse signal includes the following steps: S311, the positioning tag first sends a poll message and records the sending timestamp t0 of the poll message; next, the tag will switch to the receiving mode, wait for the reply from the positioning base station, and set a timeout limit; S312, after receiving the poll message, the positioning base station will delay replying resp messages to the positioning tag one by one according to its own device ID; the positioning base station will record the receiving timestamp t1 of the poll message and the sending timestamp t2 of the resp message; S313, when the positioning tag receives the resp message replied by the positioning base station, it records the receiving timestamp t3 of the resp message; then, the positioning tag aggregates the sending timestamp t0 of the poll message, the sending timestamp t4 of the final message and the receiving timestamp t3 of the resp message into the final message, and broadcasts it back to the positioning base station; S314. After receiving the final message, the positioning base station extracts the sending timestamp t0 of the poll message and the receiving timestamp t3 of the resp message; at the same time, the positioning base station records the receiving timestamp t5 of the final message; S315, the positioning base station starts ranging calculation after receiving all timestamps; S316, calculate the time length T by the difference between the receiving timestamp t1 of the poll message and the sending timestamp t2 of the resp message reply1 ; The time length T is calculated by the difference between the sending timestamp t0 of the poll message and the receiving timestamp t3 of the resp message round1 ; The time length T is calculated by the difference between the receiving timestamp t3 of the resp message and the sending timestamp t4 of the final message reply2 ; The time length T is calculated by the difference between the sending timestamp t2 of the resp message and the receiving timestamp t5 of the final message round2 ; S317, passing time length T reply1 、T round1 、T reply2 、T round2 Calculate the flight time T prop ; The calculation formula is: After combining the above formulas, we get: S318: The distance value Distance between the positioning tag and the positioning base station is calculated by the speed c of the radio wave and the flight time T. prop The calculation formula is: Distance=T prop ×c。 5. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 4, characterized in that: In step S3, the specific operation of the positioning base station calculating the angle value between the positioning tag and the positioning base station according to the UWB pulse signal includes the following steps: S321, the positioning tag transmits a UWB pulse signal, and a phase difference α occurs when the UWB pulse signal reaches two UWB pulse signal receiving antennas of the positioning base station; S322, the positioning base station calculates the arrival angle of the UWB pulse signal by the phase difference α; the calculation formula is: Among them, α is the phase difference between the UWB pulse signal reaching the two UWB pulse signal receiving antennas of the positioning base station, and p is the distance difference between the positioning tag and the two UWB pulse signal receiving antennas of the positioning base station; S323, introducing the distance d between the two UWB pulse signal receiving antennas, we get: p = dsinθ; S324, combining the above formulas, the arrival angle θ is obtained; the calculation formula is: The signal wavelength c is the speed of light, and fc is the signal frequency.

6. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 5, characterized in that: In step S5, the specific steps of calculating the TOF distance positioning strategy positioning result by the positioning engine through the TOF distance positioning strategy are: S511, suppose that the coal mining machine positioning system has n positioning base stations, whose coordinates are (x i ,y i ), and the distance from the positioning tag to the positioning base station is measured to be d i , where i is the positioning base station ID number, ranging from 0 to n; S512, setting the coordinates of the location tag to (x, y), then for each positioning base station, we can get: S513, use three data packets with different positioning base station IDs to perform calculations, and construct a distance equation group with the positioning base station coordinates (x0, y0), (x1, y1), (x2, y2), the positioning tag coordinates (x, y), and the distances d0, d1, and d2 from the positioning tag to the three positioning base stations, and obtain: S514, eliminate the square term and obtain the resulting equation system: S515. Combining the above formulas, using the substitution method and the elimination method, the coordinates (x, y) of the positioning tag can be solved.

7. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 6, characterized in that: In step S5, the specific steps of calculating the positioning result of the AOA angle positioning strategy by the positioning engine through the AOA angle positioning strategy are: S521, suppose that the coal mining machine positioning system has n positioning base stations, whose coordinates are (x i ,y i ), and the measured arrival angle from the positioning tag to the positioning base station is θ i , where i is the positioning base station ID number, ranging from 0 to n; S522, setting the coordinates of the location tag to (x, y), then for each positioning base station, we can get: Right now: tanθ i ·y-x=tanθ i ·y i -x i ,i=1,2,......,n; S523. Define a variable d to represent the measurement error, then the error equation can be expressed as: d=h-G a t; but: When the variable d is 0, we get: h=G a t; S524, ride on both sides It can be concluded that: S525, ride on both sides Then we can get the matrix t, which is the coordinates of the positioning label. The calculation formula of matrix t is: in, is the matrix G a The transposed matrix of is a matrix The inverse matrix of .

8. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 7, characterized in that: In step S5, the specific operation of the positioning engine calculating the infrared positioning strategy positioning result through the infrared positioning strategy is: calculating the average value of all positioning base station IDs that receive infrared signals, and the bracket frame number position corresponding to the positioning tag can be determined by the average value; the average value calculation formula of the positioning base station ID is: Wherein, M and N are IDs of different positioning base stations.

9. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 8, characterized in that: The Kalman filter algorithm continuously iterates the prediction and update process by the prediction equation and the update equation to provide the best state estimation in a noisy and uncertain environment; The prediction equation is: in, is the state value of the positioning system at time t; is the optimal value of the positioning system at time t-1; F is the state transfer matrix; B is the state control matrix; u t-1 is the model correction vector; P t - is the covariance matrix; Q is the process noise; The update equation is: Among them, K t is the Kalman gain; H is the measurement matrix; R is the Gaussian white noise; z t is the observed value.

10. The coal mining machine positioning method integrating UWB-AOA-TOF positioning and infrared detection as claimed in claim 9, characterized in that: In step S6, after the positioning engine obtains the best positioning tag coordinate value, it substitutes the best positioning tag coordinate value into the tag installation position deviation compensation algorithm to calculate the support frame number corresponding to the center point of the coal mining machine.

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