CN103899309B - Underground coal mine development machine close-distance safety detection system and detection method - Google Patents

Abstract

The invention relates to a close-distance safety detection system and a detection method of an underground roadheader in a coal mine, belonging to a coal mine short-distance safety detection system and a detection method. The detection system consists of a beacon control device installed on the roadheader and a number of mobile acquisition devices carried by the staff; the working process of the system consists of dangerous area division, system calibration, mobile acquisition device (MAD) close-range detection, and risk judgment. and the alarm response process; the system establishes a two-dimensional plane coordinate system and formulates a dangerous area model. In the coordinate system, the coordinate data information of each point in the dangerous area is determined, and the information is stored in the control processing unit; the detection model is established. And a complete detection method; and select low-frequency electromagnetic field as the detection signal medium. The invention solves the problem that personal safety accidents occur during the working process of the roadheader due to the observation blind spot of the roadheader operator in the special environment of underground tunneling.

Description

Close-range safety detection system and detection method for coal mine underground roadheader

technical field

The invention relates to a coal mine short-distance safety detection system and detection method, in particular to a coal mine underground roadheader short-distance safety detection system and detection method.

Background technique

In recent years, with the rapid development of my country's coal industry, the performance of coal mine production equipment has been greatly improved. In the underground, while the use of large-scale roadheaders can effectively improve the tunneling efficiency of coal mine roadways, due to the constraints of the narrow working space and low visibility of the tunneling face, there are also certain hidden dangers around the roadheaders. Common safety hazards Hidden dangers are as follows: when the roadheader is running, accidents such as crowding by the roadheader, broken chain of the scraper chain and injury to people will occur, accidents such as scalding or crushing accidents of workers who accidentally approach the roadheader due to excessive oil temperature will occur. The main reason for the above-mentioned roadheader injury accident is that the staff strayed into the dangerous area or the nearby people passively entered the dangerous area during the driving process of the roadheader. This not only affects the normal production and operation safety, but also affects the life safety of the field workers. posed a great threat. Therefore, in order to reduce and avoid the occurrence of such safety accidents, it is necessary to take effective measures to isolate the staff from the dangerous area. At present, coal mines often use measures such as warning signs and isolation fences to isolate workers, but the effect is not obvious. Due to the mobility of the roadheader during work, it is necessary to regularly remove and install these warning signs and fences according to the progress of the roadheader, which will also cause certain time and economic losses.

Contents of the invention

The object of the present invention is to provide a short-distance safety detection system and detection method for a coal mine underground roadheader to solve the problem of safety protection for personnel around the underground roadheader.

Technical solution: In order to achieve the above objectives, the short-distance safety detection system of the coal mine underground roadheader of the present invention is composed of a beacon control device installed on the roadheader and a plurality of mobile acquisition devices carried by the staff respectively;

The beacon control device includes a low-frequency magnetic field generating unit, a control processing unit and a correction unit; the low-frequency magnetic field generating unit is installed at the four ends of the roadheader, and the control processing unit and the correction unit are installed on the roadheader;

Described low-frequency magnetic field generating unit is made up of oscillator, active filter, power amplifier circuit and transmitting antenna; Oscillator, active filter, power amplifier circuit and transmitting antenna are connected in sequence, wherein the input end of oscillator and the control processing unit output connection;

The control processing unit is composed of STM32 microcontroller, radio frequency data communication circuit, wired data communication circuit, alarm circuit, power supply circuit, man-machine interface circuit and interface circuit; radio frequency data communication circuit, wired data communication circuit and man-machine interface The circuit is connected to the STM32 microcontroller for two-way communication, and the output terminal of the STM32 microcontroller is connected to the alarm circuit and the interface circuit, and the interface circuit is connected to the oscillator of the low-frequency magnetic field generating unit; the wired data communication circuit is connected to the input terminal of the calibration unit;

The correction unit is composed of a low-frequency magnetic field detection circuit, an STM32 microcontroller, and a wired data communication circuit; the output end of the low-frequency magnetic field detection circuit is connected to the input end of the STM32 microcontroller, and the STM32 microcontroller communicates bidirectionally with the wired data communication circuit connection, two-way communication connection between the wired data communication circuit and the wired data communication circuit of the control processing unit;

The mobile acquisition device is composed of a low-frequency magnetic field detection unit and a detection control unit; the low-frequency magnetic field detection unit includes: an antenna, a pre-stage frequency selection circuit, a signal frequency selection amplifying circuit and a true RMS detection circuit, the antenna, the pre-stage The frequency selection circuit, the signal frequency selection amplification circuit and the true RMS detection circuit are sequentially connected; the detection control unit includes: an STM32 microcontroller, a power supply circuit, a radio frequency data communication circuit, an alarm circuit and a man-machine interface circuit; the power supply circuit is The whole machine provides power, the radio frequency data communication circuit and the man-machine interface circuit are connected with the STM32 microcontroller for two-way communication, the output terminal of the STM32 microcontroller is connected with the alarm circuit, the A/D input terminal of the STM32 microcontroller is connected with the low frequency magnetic field detection unit The output terminal of the true RMS detection circuit is connected.

The detection method of the short-distance safety detection system of the coal mine underground tunneling machine of the present invention: the working process of the short-distance safety detection system is composed of dangerous area division, system calibration, mobile acquisition device MAD short-distance detection, danger judgment and alarm response process; two-dimensional Plane coordinate system and formulate the dangerous area model, in the coordinate system, determine the coordinate data information of each point in the dangerous area, and store the information in the control processing unit; system calibration and mobile acquisition device MAD short-distance detection choose strong diffraction low-frequency electromagnetic field as a signal medium;

The specific detection method is as follows:

Step 1: The control processing unit controls the correction unit to correct the system detection data according to the surrounding environment changes;

Step 2: When the maximum number of workers around the roadheader is n, the system configures n mobile acquisition devices MAD, and numbers the mobile acquisition devices MAD from 1 to n. When working, all or part of the n mobile acquisition devices MAD Effective communication range: the control processing unit of the beacon control device generates 1, 2, 3, ..., n synchronous data signals in sequence, and sends the synchronous data signals to all the surrounding mobile acquisition devices MAD through the radio frequency data communication circuit, in the effective The mobile acquisition device MAD within the communication range will return the detection data, and the mobile acquisition device MAD not within the effective communication range, the system will set the returned data to be empty; the system completes the interactive communication with multiple mobile acquisition devices MAD according to this rule, defined Completing the data communication of all mobile acquisition devices MAD is a scanning cycle;

Step 3: While performing data communication, the control processing unit sequentially controls the working sequence of the low-frequency magnetic field generating unit; set the numbers of the four low-frequency magnetic field generating units as A, B, C, D, when the control processing unit generates 1, 5, 9. When synchronizing data signals, the control processing unit controls the low-frequency magnetic field generation unit A to work, and the mobile acquisition device MAD will record the electromagnetic field strength value generated by A at this time when receiving these data signals; when 2, 6, 10, …When synchronizing data signals, control the low-frequency magnetic field generating unit B to work, and when the mobile acquisition device MAD receives these data signals, it will record the electromagnetic field strength value generated by B at this time; similarly, the low-frequency magnetic field generating units C and D work synchronously The data signals are 3, 7, 11, ... and 4, 8, 12, ...; taking 20 mobile acquisition devices MAD as an example, after one scanning cycle, each mobile acquisition device MAD will record A, B, C, D four groups, each with a total of 5 data, the mobile acquisition device MAD calculates the average value of each group of data; if a certain mobile acquisition device MAD is not always within the effective communication range, then the mobile acquisition device MAD will only be within the effective communication range Calculate the average value of the data detected within the time period; from the second scan cycle, the mobile acquisition device MAD whose number is consistent with the received synchronous data signal records the current field magnetic field strength, and records the stored data by itself. The average value of each group of detection data in the previous cycle is sent back to the control processing unit;

Step 4: The control processing unit calculates the specific position of each mobile acquisition device MAD according to the data returned by the mobile acquisition device MAD. When a mobile acquisition device MAD appears in the alarm or shutdown area, the control processing unit will control the alarm circuit or control The roadheader responds by stopping.

In said step 3, the control processing unit calculates the method for the position information of the mobile acquisition device MAD after receiving four sets of data of the mobile acquisition device MAD:

(1) Store the average value of the four groups of data A, B, C, and D;

(2) Convert the larger three values (i.e., the average value of magnetic field strength) among the average values of the four groups of data A, B, C, and D into distance information. The conversion mathematical model applied by this system is as follows:

L＝λe-(x+σ) ² /θ+ax+b

L is the distance value (/cm), x is the magnetic field strength value (detected voltage signal/mv), λ is the scale coefficient of the model, σ is the distance coefficient of the model, and θ is the magnification coefficient of the model. It is obtained by simulation, and a set of parameter values obtained by computer simulation of simulated downhole environment are given here, λ=3.099e+004, σ=3.613, θ=7.418, λ, σ, θ remain unchanged during the application process; ax +b is the fine-tuning and correction link of the system. As the environment changes, the parameters a and b are adjusted and corrected;

(3) The control processing unit calculates the position information of the mobile acquisition device MAD through a trilateral positioning algorithm according to the three distance data obtained in step (2) of the calculation method.

The correction mechanism of the correction unit in the step one:

Define the time when the system completes the calibration as the calibration cycle; the system works first to perform a calibration cycle, then executes 10 scan cycles, and then executes 1 calibration cycle and 10 scan cycles alternately;

(1) The distances between the calibration unit and the low-frequency magnetic field generating units A, B, C, and D are respectively L1, L2, L3, and L4;

(2) The control processing unit sends the synchronous data of 1', 2', 3', 4' to the correction unit. When sending 1', the control processing unit controls the low-frequency magnetic field generating unit A to work. When sending 2', B works, and C , D are similar; when the correction unit receives 1', it detects and records the magnetic field strength value sent by A at this time, and when it receives 2', it detects and records the magnetic field strength value generated by B, and C and D are similar; the correction unit records A, After B, C, and D generate four magnetic field strength values x1, x2, x3, and x4, the recorded data is sent back to the control processing unit;

(3) The control processing unit substitutes the data values x1, x2, x3, and x4 returned by the correction unit into L'λe-(x-σ) ² /θ, and calculates the distances between the correction unit and A, B, C, and D respectively L1', L2', L3', L4';L-L'=ax+b, a set of parameters a1, b1 of the correction link ax+b are calculated by L1-L1', L2-L2', and are calculated by L3- L3', L4-L4' calculate another set of parameters a2, b2 of the correction link ax+b, and finally get the real-time correction parameters a, b from the average value of a1, a2 and b1, b2.

Beneficial effects, due to the adoption of the above scheme, the present invention can overcome the influence of the complex working environment in the underground through the comprehensive utilization of electromagnetic field generation, sensor intelligent detection, and embedded system control technology, and realize rapid safety detection of personnel appearing in the dangerous area. And carry out automatic alarm and control the automatic shutdown of the roadheader to ensure the safety of underground personnel to the maximum extent. It has the characteristics of simple installation, strong practicability and high stability. At the same time, it plays an important role in reducing the labor intensity of workers and ensuring production safety. and profound meaning. The proposal of the present invention is not only of great benefit to the safe operation of the coal mine driving face, but also can be extended to other fully mechanized mining faces and working places requiring close contact safety protection.

Description of drawings

Fig. 1 is a schematic diagram of device installation of the present invention.

Fig. 2 is a block diagram of the system structure of the beacon control device of the present invention.

Fig. 3 is a structural block diagram of the mobile acquisition device (MAD) system of the present invention.

Fig. 4 is the main working flow chart of the system of the present invention.

FIG. 5 is a flow chart of system scanning in the present invention.

Fig. 6 is a flow chart of the system correction work of the present invention.

Fig. 7 is a working flowchart of the mobile collection device of the present invention.

In the figure: 1. Low-frequency magnetic field generation unit; 2. Control processing unit; 3. Calibration unit; 4. Alarm area; 5. Shutdown area; 6. Effective detection range of the system; 7. Mobile acquisition device; 8. Low-frequency magnetic field detection unit ; 9. Detection and control unit.

detailed description

The present invention will be further described below in conjunction with the embodiment in the accompanying drawings:

Embodiment 1: The short-distance safety detection system of the coal mine underground roadheader of the present invention is composed of a beacon control device installed on the roadheader and a plurality of mobile acquisition devices carried by the staff respectively;

The beacon control device includes a low-frequency magnetic field generating unit 1, a control processing unit 2 and a correction unit 3; the low-frequency magnetic field generating unit 1 is installed on the four ends of the roadheader, and the control processing unit 2 and the correction unit 3 are installed on the roadheader ;

Described low-frequency magnetic field generation unit 1 is made up of oscillator, active filter, power amplifier circuit and transmitting antenna; Oscillator, active filter, power amplifier circuit and transmitting antenna are connected in sequence, wherein the input end of oscillator and control processing unit The output terminal connection;

The control processing unit 2 is composed of STM32 microcontroller, radio frequency data communication circuit, wired data communication circuit, alarm circuit, power supply circuit, man-machine interface circuit and interface circuit. The radio frequency data communication circuit, the wired data communication circuit and the man-machine interface circuit are connected to the STM32 microcontroller for two-way communication, and the output terminal of the STM32 microcontroller is connected to the alarm circuit and the interface circuit, and the interface circuit is connected to the oscillator of the low-frequency magnetic field generating unit 1 connection; the wired data communication circuit is connected to the input end of the calibration unit;

The calibration unit 3 is composed of a low-frequency magnetic field detection circuit, an STM32 microcontroller, and a wired data communication circuit. The output end of the low-frequency magnetic field detection circuit is connected to the input end of the STM32 microcontroller, the STM32 microcontroller is connected to the wired data communication circuit for two-way communication, and the wired data communication circuit is connected to the wired data communication circuit of the control processing unit 2 for two-way communication;

The mobile acquisition device 7 is composed of a low-frequency magnetic field detection unit 8 and a detection control unit 9 . Described low-frequency magnetic field detection unit 8 comprises: antenna, pre-stage frequency-selective circuit, signal frequency-selective amplifying circuit and true effective value detection circuit, antenna, pre-stage frequency-selective circuit, signal frequency-selective amplifying circuit and true effective value detection circuit sequence Connect; the detection control unit 9 includes: STM32 microcontroller, power supply circuit, radio frequency data communication circuit, alarm circuit and man-machine interface circuit; power supply circuit provides power for the whole machine, radio frequency data communication circuit and man-machine interface circuit and The STM32 microcontroller is connected in two-way communication, the output terminal of the STM32 microcontroller is connected with the alarm circuit, the A/D input terminal of the STM32 microcontroller is connected with the output terminal of the true RMS detection circuit of the low-frequency magnetic field detection unit 8 .

The detection method of the short-distance safety detection system of the coal mine underground tunneling machine of the present invention: the working process of the short-distance safety detection system is composed of dangerous area division, system calibration, mobile acquisition device MAD short-distance detection, danger judgment and alarm response process; two-dimensional Plane coordinate system and formulate the dangerous area model, in the coordinate system, determine the coordinate data information of each point in the dangerous area, and store the information in the control processing unit; system calibration and mobile acquisition device MAD short-distance detection choose strong diffraction low-frequency electromagnetic field as a signal medium;

The specific detection method is as follows:

Step 1: The control processing unit controls the correction unit to correct the system detection data according to the surrounding environment changes;

Step 2: When the maximum number of workers around the roadheader is n, the system configures n mobile acquisition devices MAD, and numbers the mobile acquisition devices MAD from 1 to n. When working, all or part of the n mobile acquisition devices MAD Effective communication range: the control processing unit of the beacon control device generates 1, 2, 3, ..., n synchronous data signals in sequence, and sends the synchronous data signals to all the surrounding mobile acquisition devices MAD through the radio frequency data communication circuit, in the effective The mobile acquisition device MAD within the communication range will return the detection data, and the mobile acquisition device MAD not within the effective communication range, the system will set the returned data to be empty; the system completes the interactive communication with multiple mobile acquisition devices MAD according to this rule, defined Completing the data communication of all mobile acquisition devices MAD is a scanning cycle;

Step 3: While performing data communication, the control processing unit sequentially controls the working sequence of the low-frequency magnetic field generating unit; set the numbers of the four low-frequency magnetic field generating units as A, B, C, D, when the control processing unit generates 1, 5, 9. When synchronizing data signals, the control processing unit controls the low-frequency magnetic field generation unit A to work, and the mobile acquisition device MAD will record the electromagnetic field strength value generated by A at this time when receiving these data signals; when 2, 6, 10, …When synchronizing data signals, control the low-frequency magnetic field generating unit B to work, and when the mobile acquisition device MAD receives these data signals, it will record the electromagnetic field strength value generated by B at this time; similarly, the low-frequency magnetic field generating units C and D work synchronously The data signals are 3, 7, 11, ... and 4, 8, 12, ...; taking 20 mobile acquisition devices MAD as an example, after one scanning cycle, each mobile acquisition device MAD will record A, B, C, D four groups, each with a total of 5 data, the mobile acquisition device MAD calculates the average value of each group of data; if a certain mobile acquisition device MAD is not always within the effective communication range, then the mobile acquisition device MAD will only be within the effective communication range Calculate the average value of the data detected within the time period; from the second scan cycle, the mobile acquisition device MAD whose number is consistent with the received synchronous data signal records the current field magnetic field strength, and records the stored data by itself. The average value of each group of detection data in the previous cycle is sent back to the control processing unit;

Step 4: The control processing unit calculates the specific position of each mobile acquisition device MAD according to the data returned by the mobile acquisition device MAD. When a mobile acquisition device MAD appears in the alarm or shutdown area, the control processing unit will control the alarm circuit or control The roadheader responds by stopping.

In said step 3, the control processing unit calculates the method for the position information of the mobile acquisition device MAD after receiving four sets of data of the mobile acquisition device MAD:

(1) Store the average value of the four groups of data A, B, C, and D;

(2) Convert the larger three values (i.e., the average value of magnetic field strength) among the average values of the four groups of data A, B, C, and D into distance information. The conversion mathematical model applied by this system is as follows:

L＝λe-(x+σ) ² /θ+ax+b

L is the distance value (/cm), x is the magnetic field strength value (detected voltage signal/mv), λ is the scale coefficient of the model, σ is the distance coefficient of the model, and θ is the magnification coefficient of the model. It is obtained by simulation, and a set of parameter values obtained by computer simulation of simulated downhole environment are given here, λ=3.099e+004, σ=3.613, θ=7.418, λ, σ, θ remain unchanged during the application process; ax +b is the fine-tuning and correction link of the system. As the environment changes, the parameters a and b are adjusted and corrected;

(3) The control processing unit calculates the position information of the mobile acquisition device MAD through a trilateral positioning algorithm according to the three distance data obtained in step (2) of the calculation method.

The correction mechanism of the correction unit in the step one:

Define the time when the system completes the calibration as the calibration cycle; the system works first to perform a calibration cycle, then executes 10 scan cycles, and then executes 1 calibration cycle and 10 scan cycles alternately;

(1) The distances between the calibration unit and the low-frequency magnetic field generating units A, B, C, and D are respectively L1, L2, L3, and L4;

(2) The control processing unit sends the synchronous data of 1', 2', 3', 4' to the correction unit. When sending 1', the control processing unit controls the low-frequency magnetic field generating unit A to work. When sending 2', B works, and C , D are similar; when the correction unit receives 1', it detects and records the magnetic field strength value sent by A at this time, and when it receives 2', it detects and records the magnetic field strength value generated by B, and C and D are similar; the correction unit records A, After B, C, and D generate four magnetic field strength values x1, x2, x3, and x4, the recorded data is sent back to the control processing unit;

(3) The control processing unit substitutes the data values x1, x2, x3, and x4 returned by the correction unit into L'=λe-(x-σ) ² /θ, and calculates the distance between the correction unit and A, B, C, and D L1', L2', L3', L4'respectively;L-L'=ax+b, a set of parameters a1, b1 of the correction link ax+b calculated by L1-L1', L2-L2', and calculated by L3 -L3', L4-L4' calculate another set of parameters a2, b2 of the correction link ax+b, and finally get the real-time correction parameters a, b from the average value of a1, a2 and b1, b2.

In Fig. 1, the hardware part of the short-distance safety detection system of the coal mine underground heading machine of the present invention is composed of a beacon control device and a plurality of mobile acquisition devices MAD7 carried by the staff respectively. The beacon control device includes a low-frequency magnetic field generating unit 1 , a control processing unit 2 and a correction unit 3 . The low-frequency magnetic field generating unit 1 is installed on the four corners of the edge of the boring machine. The control processing unit 2 is installed in the operating room of the roadheader, and the correction unit 3 is installed at the geometric center of the roadheader. The mobile acquisition device MAD is carried by the staff and distributed around the roadheader. The English name of the mobile acquisition device is Mobileacquisitiondevice, and the English name is abbreviated as MAD.

Referring to Fig. 1, a method for dividing dangerous areas is given. In order to prevent workers from being injured by splashed rocks during the excavation of the roadheader, a 2m shutdown area and a 3m alarm area are set aside on both sides of the head of the roadheader. A parking area of 1m and an alarm area of 2m are set aside around the fuselage of the roadheader. Since the roadheader is in front of the rock during normal operation, no personnel will appear, so a 0.5m shutdown area and a 1.5m alarm area are reserved to prevent accidental injury to the staff when the roadheader is moving forward in a non-excavation state. The division of dangerous areas considers factors such as the model of the roadheader, establishes a two-dimensional plane coordinate system and formulates a dangerous area model, and the coordinate data information is stored in the control processing unit.

In FIG. 2 , the beacon control device in the present invention is composed of a low-frequency magnetic field generation unit 1 , a control processing unit 2 and a correction unit 3 . The low-frequency magnetic field generating unit includes an oscillator, an active filter, a power amplifier circuit and an antenna. The output end of the oscillator is connected to the input end of the active filter, the output end of the active filter is connected to the input end of the power amplifier circuit, and the output end of the power amplifier circuit is connected to the antenna. The control processing unit 2 includes an STM32 microcontroller, a wired data communication circuit, a radio frequency data communication circuit, a man-machine interface circuit, an alarm circuit, a power supply circuit and an interface circuit. The STM32 microcontroller connects four low-frequency magnetic field generating units through an interface circuit, drives each low-frequency magnetic field generating unit to generate electromagnetic waves of a specific frequency and controls its working clock. The wired data communication circuit is responsible for the connection and data exchange between the control processing unit and the calibration unit. The signal input/output end of the radio frequency data communication circuit is connected to the communication signal input/output end of the STM32 microcontroller, which includes a communication interface circuit and is equipped with a communication antenna to realize data communication between the control processing unit 2 and MAD7. The signal input terminal of the alarm circuit is connected to the alarm signal output terminal of the STM32 microcontroller, and the alarm function is realized by means of sound and light alarm to remind the driver to pay attention; the signal input terminal of the STM32 microcontroller receives the output signal from the man-machine interface circuit , to realize the setting and adjustment of relevant parameters. The man-machine interface circuit also includes a display device to display relevant parameters. Once a staff member enters the alarm area by mistake, the display device will display the number and location information of the staff member; the power supply circuit can Provide stable power supply to each required power supply part in the beacon control device.

In Fig. 3, mobile acquisition device MAD7 of the present invention is made up of low-frequency magnetic field detection unit 8, detection control unit 9, wherein low-frequency magnetic field detection unit 8 includes receiving antenna, pre-stage frequency selection circuit, signal frequency selection amplification circuit and true effective value detection circuit, the detection control unit 9 includes a STM32 microcontroller, a radio frequency data communication circuit, an alarm circuit, a power supply circuit and a man-machine interface circuit. The receiving antenna of the low-frequency magnetic field detection unit 8 is connected to the input end of the front-stage frequency selection circuit, the output end of the front-stage frequency selection circuit is connected to the input end of the signal frequency selection amplifier circuit, and the output end of the signal frequency selection amplifier circuit is connected to the input end of the true effective value detection circuit; The detection signal of the low-frequency magnetic field detection unit 8 goes to the A/D sampling module inside the STM32 microcontroller in the detection control unit 9, and the signal input/output end of the radio frequency data communication circuit is connected to the communication signal input/output end of the STM32 microcontroller , the signal input end of the alarm circuit is connected to the alarm signal output end of the STM32 microcontroller. The signal input terminal of the STM32 microcontroller receives the output signal from the man-machine interface circuit to realize the setting and adjustment of relevant parameters; the power supply circuit provides stable power supply to each required power supply part in MAD7.

In Fig. 4, the main work flow of the short-distance safety detection system for coal mine underground heading machine of the present invention is as follows: (1) system initialization, so that it enters a normal working cycle. (2) System correction, which corrects the system error caused by the change of the electromagnetic loss factor in the working area of the system. (3) The beacon control device scans all MAD position information. Once a MAD appears in the alarm or shutdown area, the control processing unit immediately starts the interrupt control alarm circuit and makes the roadheader respond accordingly, and at the same time sends an alarm signal to the corresponding MAD. (4) The control processing unit returns to the interrupted site to continue scanning after executing the alarm command, and stops responding after the alarm response time reaches a preset value. (5) Define the completion of all MAD communications (that is, the completion of 1~n synchronous data signal transmission) as a scan cycle. When the number of scan cycles reaches the preset value, the system will return to (2) for the next system calibration. The system works repeatedly in a cycle to ensure the safety of personnel.

In Fig. 5, the scanning process of the short-distance safety detection system of the coal mine underground heading machine of the present invention is as follows: the control processing unit at first sends synchronous signals (1～n) to all MADs, and carries out modulo 4 division to the synchronous signals, when the data signal sent When m(m<=n)mod4=0, the low-frequency magnetic field generating unit A works, and the MAD will record the electromagnetic field strength value generated by A at this time; when mmod4=1, the low-frequency magnetic field generating unit B works, and the MAD will record Now the electromagnetic field strength value produced by B; when mmod4=2, the low-frequency magnetic field generating unit C works, and MAD will record the electromagnetic field strength value produced by C at this time; when mmod4=3, the low-frequency magnetic field generating unit D works, MAD will record the value of the electromagnetic field strength generated by D at this time. After one scan cycle, each MAD will record four sets of data A, B, C, and D, and the MAD will calculate the average value of each set of data. From the second scanning cycle, the MAD with the same number as the synchronization signal returns the data recorded in the previous scanning cycle, and the control processing unit processes the data and converts it into position information. When the MAD is in the alarm or shutdown area, the system interrupts the scanning , make a corresponding alarm or shutdown response and send alarm information to the corresponding MAD, the system continues to scan after the alarm command is executed, and stops responding after the alarm response reaches the preset value. Until the control processing unit finishes sending 1-n synchronous data signals, a scanning cycle ends.

After the control processing unit receives four sets of average value data of a MAD, the method for calculating the position information of the MAD is as follows:

(1) Store the average value of each of the four groups of data A, B, C, and D;

(2) Convert the larger three values (i.e., the average value of magnetic field strength) among the average values of the four groups of data A, B, C, and D into distance information. The conversion mathematical model applied by this system is as follows:

L＝λe-(x+σ) ² /θ+ax+b

L is the distance value (/cm), x is the magnetic field strength value (detected voltage signal/mv), λ is the scale coefficient of the model, σ is the distance coefficient of the model, and θ is the magnification coefficient of the model. The simulation result shows that a set of parameter values obtained from the computer simulation of the simulated downhole environment are given, λ=3.099e+004, σ=3.613, θ=7.418, and λ, σ, θ remain unchanged during the application process. ax+b is the fine-tuning and correction link of the system. As the environment changes, the parameters a and b are adjusted to correct the system.

(3) The control processing unit calculates the position information of the MAD through the trilateral positioning algorithm according to the three distance data obtained in (2).

In Fig. 6, the correction workflow of the coal mine underground heading machine short-distance safety detection system of the present invention is as follows: the control processing unit first generates correction synchronous signals i=1', 2', 3', 4' sequentially, and respectively controls the low-frequency magnetic field generation unit A, B, C, D work, and control the working clock of the correction unit at the same time. That is, when i=1', the low-frequency magnetic field generating unit A works, and the calibration unit detects and records the low-frequency magnetic field intensity value generated by A; The low-frequency magnetic field strength value; C, D and so on. When the work of the low-frequency magnetic field generating unit D is completed, after the correction unit detects and records the low-frequency magnetic field strength value generated by D, the correction unit transmits the recorded four sets of data to the control processing unit through the wired data communication circuit, and the control processing unit processes the data. Get the value of a, b. The method of calculating a and b values is as follows:

Suppose the distances between the calibration unit 1 and the low-frequency magnetic field generating units A, B, C, and D are L1, L2, L3, and L4, respectively. The calibration unit records the four magnetic field strength values of A, B, C, and D as x1, x2, x3, and x4 respectively. The control processing unit substitutes the data values x1, x2, x3, and x4 returned by the correction unit into L'λe-(x-σ) ² /θ, and calculates the distances between the correction unit and A, B, C, and D as L1' , L2', L3', L4'. L-L'=ax+b, a set of parameters a1, b1 of the correction link ax+b calculated by L1-L1', L2-L2', and a set of parameters a1, b1 of the correction link ax+b calculated by L3-L3', L4-L4' Another set of parameters a2, b2 of b, and finally the real-time correction parameters a, b are obtained from the average value of a1, a2 and the average value of b1, b2.

In Fig. 7, the working process of the mobile acquisition device MAD of the short-distance safety detection system of the coal mine underground heading machine of the present invention is as follows: after the mobile acquisition device system is initialized, the synchronization signal sent by the control processing unit is received through the radio frequency data communication circuit, and is transmitted through the MAD. The STM32 microcontroller performs a modulo-4 division of the synchronization signal. When the synchronization signal mmod4=0, the low-frequency magnetic field detection unit of MAD detects the magnetic field strength value at this time, and stores it in Group A through the STM32 microcontroller of MAD; when the synchronization signal mmod4=1, the low-frequency magnetic field detection unit of MAD detects The magnetic field strength value at this time is stored in group B through the STM32 microcontroller of MAD; when the synchronous signal mmod4=2, the low-frequency magnetic field detection unit of MAD detects the magnetic field strength value at this time, and is sent through the STM32 microcontroller of MAD Stored in group C; when the synchronization signal mmod4=3, the low-frequency magnetic field detection unit of the MAD detects the magnetic field strength value at this time, and stores it in group D through the STM32 microcontroller of the MAD; after one scan cycle, each MAD Four sets of data A, B, C, and D will be recorded, and MAD will calculate the average value of each set of data. Starting from the second scanning period, the MAD that receives the synchronous data signal with the same number as itself sends the average value of each group of data stored in the previous period to the control processing unit. When the MAD receives the alarm signal from the control processing unit, the MAD interrupts its work and responds to the alarm. After the MAD executes the alarm command, it returns to the interruption site, and stops responding after the alarm response time reaches the preset value.

Claims (3)

1. a underground coal mine development machine close-distance safety detection system, is characterized in that: this detection system is made up of the beacon control device be arranged on development machine and multiple mobile collection device carried by staff respectively;

Described beacon control device comprises low frequency magnetic field generating unit, controlled processing unit and correcting unit; Low frequency magnetic field generating unit is arranged on four ends of development machine, and controlled processing unit and correcting unit are arranged on development machine;

Described low frequency magnetic field generating unit is made up of oscillator, active filter, power amplifier and transmitting antenna; Oscillator, active filter, power amplifier and transmitting antenna are linked in sequence, and wherein the input of oscillator is connected with the output of controlled processing unit;

Described controlled processing unit is made up of STM32 microcontroller, rf data communicating circuit, cable data communicating circuit, warning circuit, power supply circuits, man-machine interface circuit and interface circuit; Rf data communicating circuit, cable data communicating circuit are connected with STM32 microcontroller both-way communication with man-machine interface circuit, be connected with warning circuit and interface circuit at the output of STM32 microcontroller, interface circuit is connected with the oscillator of low frequency magnetic field generating unit; Cable data communicating circuit is connected with the input of correcting unit;

Described correcting unit is made up of low frequency magnetic field testing circuit, MCU controller, cable data communicating circuit; The output of low frequency magnetic field testing circuit is connected with the input of MCU controller, and MCU controller is connected with cable data communicating circuit both-way communication, and cable data communicating circuit is connected with the cable data communicating circuit both-way communication of controlled processing unit;

Described mobile collection device is made up of low frequency magnetic field detecting unit, detection control unit; Described low frequency magnetic field detecting unit comprises: antenna, prime frequency selection circuit, signal selective frequency amplifier circuit and true virtual value detection circuit, and antenna, prime frequency selection circuit, signal selective frequency amplifier circuit and true virtual value detection circuit are linked in sequence; Described detection control unit comprises: STM32 microcontroller, power supply circuits, rf data communicating circuit, warning circuit and man-machine interface circuit; Power supply circuits provide power supply for complete machine, rf data communicating circuit is connected with STM32 microcontroller both-way communication with man-machine interface circuit, the output of STM32 microcontroller is connected with warning circuit, and the A/D input of STM32 microcontroller is connected with the output of the true virtual value detection circuit of low frequency magnetic field detecting unit.

2. the detection method of underground coal mine development machine close-distance safety detection system according to claim 1, is characterized in that: detection method: this close-distance safety detection system course of work is closely detected by risk zontation, system compensation, mobile collection device MAD, danger judgement and alarm response flow are formed; Set up two dimensional surface coordinate system and formulate deathtrap model, in coordinate system, determining the coordinate data information of each point in deathtrap, and this information is stored in controlled processing unit; System compensation and mobile collection device MAD closely detect and select diffractive strong low frequency electromagnetic field as signal medium;

Concrete detection method is as follows:

The first step: controlled processing unit controls correcting unit and corrects systems axiol-ogy data according to surrounding environment change;

Second step: when development machine surrounding work personnel number is n people to the maximum, system configuration n mobile collection device MAD, and mobile collection device MAD is numbered 1 ~ n, during work, n mobile collection device MAD's is all or part of in effective communication scope; The controlled processing unit of beacon control device produces 1 successively, 2,3 ..., a n synchronized data signal, and by rf data communicating circuit, synchronized data signal is sent to all mobile collection device MAD around, mobile collection device MAD within the scope of effective communication will return detection data, mobile collection device MAD not within the scope of effective communication, system will arrange return data for empty; System completes with this rule and interactive correspondence between multiple mobile collection device MAD, and the data communication having defined whole mobile collection device MAD is a scan period;

3rd step: while carrying out data communication, controlled processing unit controls the job order of low frequency magnetic field generating unit successively; If four low frequency magnetic field generating units are numbered A, B, C, D, when controlled processing unit produce 1,5,9 ... during synchronized data signal, controlled processing unit controls low frequency magnetic field generating unit A work, will record the electromagnetic field intensity angle value now produced by A when mobile collection device MAD receives these data-signals; When generation 2,6,10 ... during synchronized data signal, control low frequency magnetic field generating unit B work, when mobile collection device MAD receives these data-signals, will the electromagnetic field intensity angle value now produced by B be recorded; In like manner, the work synchronized data signal of low frequency magnetic field generating unit C, D be 3,7,11 ... with 4,8,12, When mobile collection device MAD is 20, after a scan period, each mobile collection device MAD is by record A, B, C, D tetra-groups, often organize totally 5 data, and mobile collection device MAD calculates the average often organizing data; If certain mobile collection device MAD is not always within the scope of effective communication, then this mobile collection device MAD only by within the scope of effective communication time the data calculating mean value that detects; From second scan period, mobile collection device MAD numbers the mobile collection device MAD consistent with the synchronized data signal received, while record current field electromagnetic field intensity angle value, the often group in upper cycle self record stored detects statistical average and sends it back controlled processing unit;

4th step: the data that controlled processing unit returns according to mobile collection device MAD; calculate the particular location of each mobile collection device MAD; when there being mobile collection device MAD appear at warning or shut down region, controlled processing unit will control warning circuit or control the response that parking made by development machine.

3. the detection method of underground coal mine development machine close-distance safety detection system according to claim 2, it is characterized in that: in described step 3, controlled processing unit calculates the method for mobile collection device MAD positional information in the four groups of data receiving a mobile collection device MAD:

(1) average of A, B, C, D tetra-groups of data is stored;

(2) by three values larger in A, B, C, D tetra-groups of statistical average, namely electromagnetic field intensity angle value average is converted to range information, and the conversion Mathematical Modeling of native system application is as follows:

L=

L is distance value, and unit cm, x are electromagnetic field intensity angle value, detects to obtain voltage signal, unit mv, λ are the factor of proportionality of model, and σ is the distance coefficient of model, θ is the multiplying power factor of model, and drawn by large amount measurement data and computer simulation emulation, λ, σ, θ remain unchanged in application process; for the fine setting correction link of system, along with the change of environment, adjustment corrective system is carried out to parameter a, b;

(3) controlled processing unit calculates the positional information of this mobile collection device MAD by three limit location algorithms according to three range data obtained in computational methods step (2);

The correction mechanism of correcting unit in described step one:

The time that define system completes correction is calibration cycle; System works first performs a calibration cycle, then performs 10 scan periods, and later 1 calibration cycle and 10 scan periods alternately perform successively;

(1) distance of correcting unit and low frequency magnetic field generating unit A, B, C, D is established to be respectively L1, L2, L3, L4;

(2) controlled processing unit sends the synchrodata of 1 ', 2 ', 3 ', 4 ' to correcting unit, and when sending 1 ', controlled processing unit controls low frequency magnetic field generating unit A work, and when sending 2 ', B works, and when sending 3 ', C works, and when sending 4 ', D works; When correcting unit receives 1 ', detect and record the electromagnetic field intensity angle value that now A sends, when receiving 2 ', detect and record B occur electromagnetic field intensity angle value, when receiving 3 ', detect and record the electromagnetic field intensity angle value that C sends, when receiving 4 ', detect and record the electromagnetic field intensity angle value that D occurs; Correcting unit is recorded A, B, C, D and four electromagnetic field intensity angle value x1 is occurred, and after x2, x3, x4, the data recorded is sent it back controlled processing unit;

(3) the data value x1 that returned by correcting unit of controlled processing unit, x2, x3, x4 substitute into

in, the distance calculating correcting unit and A, B, C, D is respectively L1 ', L2 ', L3 ', L4 '; L-L '= , by L1-L1 ', L2-L2 ' and calculate correction link one group of parameter a1, b1, by L3-L3 ', L4-L4 ' calculate correction link another group parameter a2, b2, finally obtain real time correction parameter a, b by the average of a1, a2 and the average of b1, b2.