Dynamic control method of wireless equipment transmission power based on mine electromagnetic radiation safety

Abstract

The present invention discloses a method for dynamically controlling the transmission power of wireless devices based on the electromagnetic radiation safety of mines, and belongs to the field of electromagnetic radiation safety and communication technology in underground confined spaces. Two electromagnetic radiation security base stations with wired connections are installed at both ends of the electromagnetic safety protection zone of the mine, and the wireless device sends its own electromagnetic radiation data to the electromagnetic radiation security base station. The electromagnetic radiation security base station analyzes, evaluates and predicts the data, and obtains the maximum allowable transmission power of the wireless device that affects the electromagnetic safety protection zone. The wireless device adjusts its own transmission power according to the analysis result; including: electromagnetic radiation data collection stage, space-time-frequency domain electromagnetic radiation safety assessment stage, maximum transmission power safety threshold definition and release stage of all wireless devices, and wireless device transmission power dynamic adjustment stage. This method maintains the quality of wireless communication services in the mine under the premise of ensuring the electromagnetic radiation safety of the mine.

Description

Technical Field

[0001] The invention relates to a method for dynamically controlling the transmission power of wireless equipment with the requirements of electromagnetic safety protection of mines, and belongs to the technical field of electromagnetic radiation safety and communication in underground confined spaces such as tunnels and mines. Technical Background

[0002] For underground confined spaces such as coal mines where flammable and explosive substances such as gas and dust exist, the electromagnetic waves radiated by wireless devices during communication are potential detonation factors. With the development of wireless networks and electronic technology, the number of wireless devices used in underground coal mines and other spaces has increased rapidly. These wireless devices support the construction and operation of smart mines, but also lead to an unprecedented increase in the risk of electromagnetic radiation in mines.

[0003] The potential electromagnetic radiation risk in the mine is closely related to the communication load of the wireless device. When the concurrent communication data of the wireless device in the mine is small, the electromagnetic radiation power of the mine is small, and the electromagnetic radiation risk is low. Under the premise of meeting the safety electromagnetic radiation of the flammable and explosive environment, the wireless devices involved in the communication can appropriately increase the transmission power according to the needs of the communication service quality. On the contrary, the electromagnetic radiation risk of the mine is high, and the wireless devices involved in the communication need to reduce the transmission power.

[0004] However, the existing mine wireless equipment transmission power control methods often do not consider the potential electromagnetic radiation risks, and only consider it from the perspective of network service requirements. In addition, the maximum safe transmission power threshold allowed for mine wireless equipment is usually fixed. This method of solidifying the maximum safe transmission power threshold of wireless equipment results in an extremely limited range of transmission power that can be flexibly configured for mine wireless equipment. When the electromagnetic signal attenuation in the mine is large due to narrow space, electromagnetic reflection, and many scatterers, the performance of wireless communication services that require high transmission power support will not be maximized. In addition, this method ignores the impact of concurrent electromagnetic radiation from multiple mine wireless devices on the risk of detonation in flammable and explosive areas. When the deployment density of mine wireless devices is large enough and the concurrent communication data is large enough, even if each device transmits at low power, the superimposed power generated by its concurrent electromagnetic radiation may still exceed the minimum ignition power threshold of the flammable and explosive environment, thereby causing safety accidents. Summary of the invention

[0005] Technical problem: In view of the shortcomings of the existing technology, a method for dynamic control of the transmission power of wireless devices based on mine electromagnetic radiation safety is provided. This method does not fix the maximum transmission power threshold of the wireless device, but fully considers the actual dynamic changes of the electromagnetic radiation power distribution in the mine, and provides a space-time-frequency three-domain measurement method for mine electromagnetic radiation safety and a method for defining the maximum transmission power threshold of wireless devices. This method can avoid the impact of transmission power limitation on the communication service quality of wireless devices as much as possible under the premise of ensuring electromagnetic radiation safety. It is very suitable for smart mine scenarios with collaborative communication among multiple wireless devices and massive data transmission.

[0006] Technical solution: To achieve the above technical objectives, the method for dynamically controlling the transmission power of wireless devices based on electromagnetic radiation safety in mines of the present invention comprises installing an electromagnetic radiation security base station at each end of the electromagnetic safety protection zone of the mine, wherein the two electromagnetic radiation security base stations communicate with the wireless devices fixedly installed within the coverage area through a wireless network, and the two electromagnetic radiation security base stations communicate with each other through a wired manner; the wireless device sends its own electromagnetic radiation data to the electromagnetic radiation security base station, and the electromagnetic radiation security base station analyzes, evaluates and predicts the data to obtain the maximum allowable transmission power of the wireless device that affects the electromagnetic safety protection zone, and the wireless device adjusts its own transmission power according to the analysis results; the distribution control of the transmission power of the wireless device includes four stages: the electromagnetic radiation data collection stage, the space-time-frequency domain electromagnetic radiation safety assessment stage, the maximum transmission power safety threshold definition and release stage of all wireless devices, and the dynamic adjustment stage of the transmission power of the wireless device;

[0007] The specific steps of allocating and controlling the transmission power of wireless devices are as follows:

[0008] Step 1, electromagnetic radiation data collection phase: two electromagnetic radiation security base stations are used to collect electromagnetic radiation data of each wireless device wirelessly connected to the wireless network within the coverage area. The coverage area of ​​the two security base stations is larger than the electromagnetic safety protection zone. At the same time, the electromagnetic field within the electromagnetic safety protection zone may also be radiated by devices outside the zone.

[0009] Step 2, electromagnetic radiation safety assessment phase in space-time-frequency domain: two electromagnetic radiation security base stations share the data received from each other through wired communication, and then use the giant lossy dielectric wall multi-mode waveguide theory to build an accurate model of underground electromagnetic wave propagation, and calculate the space-time-frequency domain distribution power of electromagnetic waves in the electromagnetic safety protection zone based on the electromagnetic radiation data of each mine wireless device, and measure the five-dimensional distribution parameters of the area, time and frequency of the detonation risk of electromagnetic radiation in this zone in the space-time-frequency domain;

[0010] Step 3, the phase of defining and publishing the maximum transmission power safety threshold of all wireless devices: the electromagnetic radiation security base station constructs a domain-time-frequency domain mapping table for unsafe electromagnetic radiation equipment in the mine, iteratively evaluates and defines the maximum safe transmission power of wireless devices that radiate electromagnetic waves at unsafe time-frequency based on the link quality priority rule. Since the safety threshold of each wireless device is different, a time-frequency configuration table of the maximum transmission power safety threshold of all wireless devices within the coverage area is established to record the corresponding safety configuration information of each wireless device. The configuration table is periodically refreshed and broadcast in the safety power configuration signaling of the electromagnetic radiation security base station according to the preset requirements;

[0011] Step 4, wireless device transmit power dynamic adjustment stage: each wireless device dynamically adjusts its transmit power within a specified safe power range within different time and frequency ranges according to the received wireless device maximum transmit power safety threshold time-frequency configuration table.

[0012] Further, the step 1 is specifically as follows:

[0013] Step 1.1, two electromagnetic radiation security base stations send safety power configuration signaling to the wireless device through wireless broadcasting, and the signaling defines the effective time of the wireless device maximum transmission power safety threshold time-frequency configuration table to be released;

[0014] Step 1.2, the wireless devices that receive the signaling feed back their own electromagnetic radiation data tables to the electromagnetic radiation security base station. The contents of the electromagnetic radiation data table include the ID number of the wireless device, the adjustable value of the transmission power, the absolute position coordinates, the frequency of the electromagnetic signal planned to be transmitted within the effective time, and the absolute length of time spent;

[0015] Step 1.3: The two electromagnetic radiation security base stations share the electromagnetic radiation data tables of wireless devices received by each other in a wired manner.

[0016] Further, the step 2 is specifically as follows:

[0017] Step 2.1, the electromagnetic radiation security base station is based on the electromagnetic radiation data of wireless devices collected in step 1 and the geological data of the mine three-dimensional map. It uses the theory of giant lossy dielectric wall multi-mode waveguide to build an underground electromagnetic wave propagation power model, and estimates the electromagnetic radiation complex power of each wireless device in the mine electromagnetic safety protection zone when each wireless device transmits a signal at maximum power: The serial number i corresponds to the ID number of the i-th wireless device; the internal space of the mine adopts a Cartesian coordinate system, and (x, y, z), f and t represent the absolute position coordinate value, frequency and time in the mine respectively; the three-dimensional map geological data of the mine includes detailed surveying and mapping map data, geological data, geometric structure and size of the tunnel, roughness, inclination, curvature of the rock on the tunnel wall and electrical parameters of the rock medium;

[0018] Step 2.2: Estimate the space-time-frequency distribution power of electromagnetic waves in the mine using the following formula:

[0019]

[0020] Step 2.3: Based on the shortest ignition time Δt and the corresponding minimum ignition average power threshold P in the flammable and explosive environment threshold , estimate the safety factor S(f,t,x,y,z) of the electromagnetic wave power radiated by the mine electromagnetic wave at time point t, frequency f, and coordinates (x,y,z). The calculation formula of S(f,t,x,y,z) is as follows:

[0021]

[0022] Step 2.4, use the time domain and space domain to interpolate the electromagnetic wave power safety factor S(f,t,x,y,z). When S(f,t,x,y,z)≥1, it means that there is a risk of electromagnetic radiation at this time. Establish a five-dimensional distribution parameter table of unsafe electromagnetic radiation in the space-time-frequency domain of mines, and record the (f,t,x,y,z) parameters corresponding to the risky S(f,t,x,y,z) in the five-dimensional distribution parameter table of unsafe electromagnetic radiation in the space-time-frequency domain of mines. The table uses its three-dimensional centroid coordinates and area radius for description; the format of the five-dimensional distribution parameter table is as follows:

[0023]

[0024] Further, the step 3 is specifically as follows:

[0025] Step 3.1: Based on step 1 and step 2.4, establish a mine unsafe electromagnetic radiation device domain-time-frequency domain mapping table to check for wireless devices that radiate electromagnetic waves at unsafe times and frequencies, and use the electromagnetic radiation weighted matching value Dan to mark risky wireless devices. The device domain-time-frequency domain mapping table format is as follows:

[0026]

[0027] The unsafe time range in the table [t s ,t o ] and unsafe frequency range [f d ,f u ] is the time and frequency range in the space-time-frequency domain five-dimensional distribution parameter table of unsafe electromagnetic radiation in the mine; if the working time of the wireless device meets t s ≤t≤t o In the unsafe frequency band f d ≤f≤f uIf it radiates electromagnetic waves, it can be judged as a risky device, and the marked Dan value is set to 1. Otherwise, it is a safe device and the Dan value is 0.

[0028] Step 3.2: Create and initialize the wireless device maximum transmission power safety threshold time-frequency configuration table: The table contains the wireless device ID number, mine unsafe electromagnetic radiation time, frequency, and wireless device maximum transmission power safety threshold. The format is as follows:

[0029] Wireless device ID Time Range frequency Maximum transmit power safety threshold

[0030] The initial values ​​of the time range and frequency in the maximum transmission power safety threshold time-frequency configuration table are set as follows: if the wireless device is always a safe device, its value is the longest valid time range specified by the safety power configuration signaling and the frequency at which the wireless device can operate; otherwise, the time range and frequency of the wireless device are the time range and frequency corresponding to the mine unsafe electromagnetic radiation equipment domain-time-frequency domain mapping table, and the initial value of the maximum transmission power safety threshold in the evaluation table is the maximum transmission power of the wireless device;

[0031] Step 3.3: Due to the uneven spatial distribution of electromagnetic waves, the areas with strong electromagnetic fields in the electromagnetic safety protection zone are relatively dangerous, while the areas with weak electromagnetic fields are relatively safe. Therefore, the average radiation power P of each risk device radiating electromagnetic waves at each unsafe time-frequency in the unsafe area is compared. j , where j represents the ID number of the risky device; then the maximum transmit power safety threshold of the risky device is evaluated based on the link quality priority rule,

[0032] P j The calculation method is as follows:

[0033]

[0034] represents the electromagnetic radiation complex power of the jth risk device, calculated according to the method in step 2.1,

[0035] The initial value is the value generated by the j-th risk device transmitting at maximum power;

[0036] The method for defining the maximum safe power threshold of risky devices based on the link quality priority rule is as follows:

[0037] Step 3.3.1: Calculate according to the above formula and based on the average radiation power P of the risk equipment j Sort the risk devices in descending order, P j The largest devices have the best link quality.

[0038] Step 3.3.2, based on the data collected in step 1, query the adjustable transmit power value of the risk device with the best link quality, reduce its transmit power by one level, and refresh the transmit power safety threshold in the wireless device maximum transmit power safety threshold time-frequency configuration table;

[0039] Step 3.3.3, using the modeling and measurement calculation method of steps 2.1 to 2.3, the transmission parameters of all wireless devices are set according to the data of the frequency configuration table of the maximum transmission power safety threshold of the wireless device, and the electromagnetic wave radiation safety factor S (f, t, x, y, z) under the unsafe time-frequency-area of ​​the mine is iteratively evaluated;

[0040] Step 3.3.4: If S(f, t, x, y, z) ≥ 1, re-execute steps 3.3.1 to 3.3.3 according to the current wireless device maximum transmission power safety threshold frequency configuration table data until all connected wireless devices satisfy S(f, t, x, y, z) < 1, that is, the electromagnetic radiation risk disappears.

[0041] Beneficial effects. 1) This method enables the maximum transmission power safety threshold of mine wireless equipment to be defined according to the actual electromagnetic radiation situation, which is more scientific and reasonable than the existing technology; 2) This method can effectively avoid the electromagnetic radiation risk caused by concurrent communication of multiple wireless devices in the mine, further improving the electromagnetic radiation safety of the mine; 3) This method dynamically configures the maximum transmission power safety threshold of each wireless device according to the communication load demand and the electromagnetic radiation risk assessment mechanism, so that the wireless equipment in the mine is not only intrinsically safe and explosion-proof, but also maximizes the power demand of wireless communication, maintaining the communication link quality and working performance of the wireless equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of a method for dynamically controlling the transmission power of wireless equipment based on mine electromagnetic radiation safety of the present invention;

[0043] Figure 2 This is a diagram of a wireless device transmission power dynamic control system based on mine electromagnetic radiation safety according to an embodiment of the present invention;

[0044] Figure 3 It is a flow chart of a method for defining a maximum safe power threshold of a risk device based on a link quality priority rule according to the present invention.

[0045] Specific implementation method

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings. The described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention:

[0047] like Figure 1 and Figure 2As shown, a method for dynamically controlling the transmission power of wireless devices based on electromagnetic radiation safety in mines of the present invention is to install an electromagnetic radiation security base station at each end of the electromagnetic safety protection zone in the mine. When the maximum size of the mine cross section is w, the length of the electromagnetic safety protection zone in the mine is d, and the maximum communication radius of the wireless device that can radiate electromagnetic waves to the electromagnetic safety protection zone is r wireless When the wireless communication radius r of the electromagnetic radiation security base station needs to meet the condition The two electromagnetic radiation security base stations communicate in a wired manner and cooperate with the wireless devices. The allocation and control of the wireless device transmission power includes four stages: electromagnetic radiation data collection stage, space-time-frequency domain electromagnetic radiation safety assessment stage, wireless device maximum transmission power safety threshold definition and release stage, and wireless device transmission power dynamic adjustment stage.

[0048] The specific steps are as follows:

[0049] Step 1, electromagnetic radiation data collection phase. The electromagnetic radiation security base station collects electromagnetic radiation data of wireless devices in mines.

[0050] Step 2, space-time-frequency domain electromagnetic radiation safety assessment stage. The electromagnetic radiation security base station uses the giant lossy dielectric wall multi-mode waveguide theory to build an accurate model of underground electromagnetic wave propagation, and calculates the space-time-frequency domain distribution power of electromagnetic waves in the electromagnetic safety protection zone based on the data in step 1, and measures the five-dimensional distribution parameters of unsafe electromagnetic radiation in the space-time-frequency domain in this zone.

[0051] Step 3: Definition and release of the maximum transmission power safety threshold of wireless devices. The electromagnetic radiation security base station constructs a domain-time-frequency domain mapping table for unsafe electromagnetic radiation equipment in mines, iteratively evaluates and defines the maximum safe transmission power of wireless devices that radiate electromagnetic waves at unsafe time-frequency based on the link quality priority rule, establishes a time-frequency configuration table for the maximum transmission power safety threshold of wireless devices, and releases it in the form of wireless broadcast.

[0052] Step 4, wireless device transmit power dynamic adjustment stage: The wireless devices dynamically adjust their transmit power according to the received wireless device maximum transmit power safety threshold time-frequency configuration table.

[0053] The step 1 is specifically as follows:

[0054] Step 1.1 The electromagnetic radiation security base station initiates a safety power configuration signaling through wireless broadcasting. The signaling defines the effective time of the wireless device maximum transmission power safety threshold time-frequency configuration table to be released.

[0055] Step 1.2 The wireless devices that receive the signaling report their own electromagnetic radiation data tables in a single-hop or multi-hop transmission mode. The contents of the electromagnetic radiation data table include the wireless device ID number, adjustable transmission power value, absolute position coordinates, the frequency of electromagnetic signal transmission planned within the effective time, the absolute time length, and other information. The electromagnetic radiation data table format is as follows:

[0056]

[0057] Step 1.3 The two electromagnetic radiation security base stations share the electromagnetic radiation data tables of wireless devices received by each other in a wired manner. The specific details of step 2 are as follows:

[0058] Step 2.1: Based on the electromagnetic radiation data of wireless devices collected in step 1 and the geological data of the mine's three-dimensional map, the electromagnetic radiation security base station uses the giant lossy dielectric wall multi-mode waveguide theory to build an underground electromagnetic wave propagation power model, and estimates the electromagnetic radiation complex power of each wireless device in the mine's electromagnetic safety protection zone when transmitting signals at maximum power. The serial number i corresponds to the ID number of the i-th wireless device; the internal space of the mine adopts the Cartesian coordinate system, and (x, y, z), f and t represent the absolute position coordinate value, frequency and time in the mine respectively. The three-dimensional mine map geological data includes the geometric structure and size of the tunnel in the mine, the roughness, inclination, curvature of the tunnel wall rock and the electrical parameters of the rock medium.

[0059] Step 2.2: Estimate the space-time-frequency distribution power of electromagnetic waves in the mine The calculation formula is:

[0060]

[0061] Step 2.3: Based on the shortest ignition time Δt and the corresponding minimum ignition average power threshold P in the flammable and explosive environment threshold , estimate the safety factor S(f,t,x,y,z) of the electromagnetic wave power radiated by the mine electromagnetic wave at time point t, frequency f, and coordinates (x,y,z). The calculation formula of S(f,t,x,y,z) is as follows:

[0062]

[0063] Step 2.4: Interpolate the electromagnetic wave power safety factor S(f, t, x, y, z) in the time domain and space domain. After interpolation, (f, t, x, y, z) is a continuous value. s ≤t≤t o Time period, f d ≤f≤f uWhen S(f, t, x, y, z) ≥ 1 in the frequency band, it means that there is a risk of electromagnetic radiation at this time, and the (f, t, x, y, z) parameters at this time are recorded in the five-dimensional distribution parameter table of unsafe electromagnetic radiation in the space-time-frequency domain of mines. s ,t o They are the start time and end time of unsafe electromagnetic radiation in the mine, f d ,f u The lowest and highest frequencies of unsafe electromagnetic radiation in mines are shown in the table. The unsafe electromagnetic radiation areas are represented by their three-dimensional centroid coordinates (x0, y0, z0) and area radius r rad Description. The format of the five-dimensional distribution parameter table is as follows:

[0064]

[0065] The step 3 is as follows:

[0066] Step 3.1: Based on step 1 and step 2.4, establish a mine unsafe electromagnetic radiation equipment domain-time-frequency domain mapping table to check for wireless devices that radiate electromagnetic waves at unsafe times and frequencies, and use the electromagnetic radiation weighted matching value Dan to mark them as risky devices. The equipment domain-time-frequency domain mapping table format is as follows:

[0067]

[0068] The time range in the table [t s ,t o ] and frequency range [f d ,f u ] is the time and frequency range in the five-dimensional distribution parameter table of the mine unsafe electromagnetic radiation space-time-frequency domain. If the equipment is at t s ≤t≤t o , unsafe frequency band f d ≤f≤f u If it radiates electromagnetic waves, it is a risky device and the value of Dan is 1. Otherwise, it is a safe device and the value of Dan is 0.

[0069] Assume that there are 6 devices in the electromagnetic radiation data table of wireless devices in this embodiment, and refer to the five-dimensional distribution parameter table of space-time-frequency domain of unsafe electromagnetic radiation in mines. s1 ,t o1 ] and frequency band [f d1 ,f u1 ], ID1, ID2, and ID5 devices transmit signals and are risky devices; during the unsafe radiation period [t s2 ,t o2 ] and frequency band [f d2 ,f u2], ID2, ID3, and ID6 devices transmit signals and are risky devices; then the device domain-time-frequency domain mapping table is as follows:

[0070]

[0071] Step 3.2: Establish and initialize the wireless device maximum transmission power safety threshold time-frequency configuration table. The evaluation table contains the wireless device ID number, mine unsafe electromagnetic radiation time, frequency, and wireless device maximum transmission power safety threshold, and the format is as follows:

[0072] Wireless device ID Time Range frequency Maximum transmit power safety threshold

[0073] The initial values ​​of the time range and frequency in the evaluation table are set as follows: if the wireless device is always a safe device, its value is the longest valid time range and the frequency at which the device can work specified by the safe power configuration signaling. Otherwise, the time range and frequency of the device are the time range and frequency corresponding to the mine unsafe electromagnetic radiation device domain-time-frequency domain mapping table. The initial value of the maximum transmission power safety threshold in the evaluation table is the maximum transmission power of the device.

[0074] Assume that the maximum valid time range specified by the safety power configuration signaling in this embodiment is t ps ≤t≤t po , the frequency of the i-th device working in this period is f i , the adjustable transmission power values ​​are 0, and Its initial value in the wireless device maximum transmit power safety threshold time-frequency configuration table is as follows:

[0075]

[0076] Step 3.3: Compare the average radiation power P of the risk equipment for radiating electromagnetic waves at each unsafe time-frequency in each unsafe area j , where j represents the jth risk device and uniquely corresponds to the device ID number. Then, the maximum safe power of the risk device is evaluated based on the link quality priority rule.

[0077] P j The calculation method is as follows:

[0078]

[0079] represents the electromagnetic radiation complex power of the jth risk device. Calculate it according to the method in step 2.1.

[0080] The initial value is the value generated by the j-th risk device transmitting at maximum power.

[0081] like Figure 3 As shown, the method for defining the maximum safe power threshold of risky devices based on the link quality priority rule is performed in the following steps:

[0082] a1. Calculate according to the above formula and based on the average radiation power P of the risk equipment j Sort the risky devices in descending order. j The largest devices have the best link quality.

[0083] a2. Based on the data collected in step 1, query the adjustable transmit power value of the risk device with the best link quality, reduce its transmit power by one level, and refresh the transmit power safety threshold in the wireless device maximum transmit power safety threshold time-frequency configuration table.

[0084] Assume that in this embodiment, during the unsafe radiation time period [t s1 ,t o1 ] and frequency band [f d1 ,f u1 ], ID1, ID2, and ID5 devices transmit signals. According to the calculation of the average radiation power of ID1, ID2, and ID5 devices as follows: P1>P5>P2, then ID1 has the best link quality. According to the assumptions of this embodiment, refresh the value of ID1 in the wireless device maximum transmission power safety threshold frequency configuration table:

[0085]

[0086] In the table, f1 is the ID1 in [t s1 ,t o1 ] time range, its value is between [f d1 ,f u1 ] interval.

[0087] a3. Using the modeling and measurement calculation methods of steps 2.1-2.3, the transmission parameters of all wireless devices are set according to the data of the frequency configuration table of the maximum transmission power safety threshold of the wireless device, and the electromagnetic wave radiation safety factor S(f, t, x, y, z) of the unsafe time-frequency-area of ​​the mine is iteratively evaluated.

[0088] a4. If S(f,t,x,y,z)≥1, re-execute steps a1-a3 according to the current wireless device maximum transmit power safety threshold frequency configuration table data until S(f,t,x,y,z)<1, that is, the electromagnetic radiation risk disappears.

[0089] Assuming that in this embodiment, after step a3, it is calculated that S(f, t, x, y, z) ≥ 1, then steps a1-a3 should be re-executed, wherein the transmit power of ID1 is set to the new value calculate.

[0090] If after calculation in step a1, during the unsafe radiation period [t s1 ,t o1 ] and frequency band [f d1 ,f u1 ], the new average radiation power of devices ID1, ID2, and ID5 is ranked as follows: P5>P1>P2, and ID5 has the best link quality.

[0091] In step a2, the value of ID5 in the wireless device maximum transmit power safety threshold time-frequency configuration table is refreshed:

[0092]

[0093] In step a3, S(f, t, x, y, z) is calculated, where the transmit power of ID1 is adjusted to the new value Calculate the transmit power of ID5 according to the new value Calculate. If S(f, t, x, y, z) < 1, then the unsafe radiation time period [t s1 ,t o1 ], frequency band [f d1 ,f u1 ]'s electromagnetic radiation risk disappears, and the definition of the maximum transmission power safety threshold of the wireless device is completed; otherwise, continue to execute a1-a3.

[0094] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, but they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for dynamically controlling the transmission power of wireless equipment based on mine electromagnetic radiation safety, characterized in that: An electromagnetic radiation security base station is installed at each end of the electromagnetic safety protection zone of the mine. The two electromagnetic radiation security base stations communicate with fixed wireless devices within the coverage area through a wireless network, and the two electromagnetic radiation security base stations communicate with each other through wired means; The wireless device sends its electromagnetic radiation data to the electromagnetic radiation security base station, which analyzes, evaluates and predicts the data to obtain the maximum allowable transmission power of the wireless device that affects the electromagnetic safety protection zone. The wireless device adjusts its transmission power according to the analysis results. The allocation control of the transmission power of the wireless device includes four stages: electromagnetic radiation data collection stage, space-time-frequency domain electromagnetic radiation safety assessment stage, maximum transmission power safety threshold definition and release stage of all wireless devices, and dynamic adjustment stage of wireless device transmission power. The specific steps of allocating and controlling the transmission power of wireless devices are as follows: Step 1, electromagnetic radiation data collection phase: two electromagnetic radiation security base stations are used to collect electromagnetic radiation data of each wireless device wirelessly connected to the wireless network within the coverage area. The coverage area of ​​the two security base stations is larger than the electromagnetic safety protection area. At the same time, the electromagnetic field within the electromagnetic safety protection area is also radiated by devices outside the area. Step 2, electromagnetic radiation safety assessment phase in space-time-frequency domain: two electromagnetic radiation security base stations share the data received from each other through wired communication, and then use the giant lossy dielectric wall multi-mode waveguide theory to build an accurate model of underground electromagnetic wave propagation, and calculate the space-time-frequency domain distribution power of electromagnetic waves in the electromagnetic safety protection zone based on the electromagnetic radiation data of each mine wireless device, and measure the five-dimensional distribution parameters of the area, time and frequency of the detonation risk of electromagnetic radiation in this zone in the space-time-frequency domain; Step 2.1, the electromagnetic radiation security base station is based on the electromagnetic radiation data of wireless devices collected in step 1 and the geological data of the mine three-dimensional map. It uses the theory of giant lossy dielectric wall multi-mode waveguide to build an underground electromagnetic wave propagation power model, and estimates the electromagnetic radiation complex power of each wireless device in the mine electromagnetic safety protection zone when each wireless device transmits a signal at maximum power: The serial number i corresponds to the ID number of the i-th wireless device; the internal space of the mine adopts a Cartesian coordinate system, and (x, y, z), f and t represent the absolute position coordinate value, frequency and time in the mine respectively; the three-dimensional map geological data of the mine includes detailed surveying and mapping map data, geological data, geometric structure and size of the tunnel, roughness, inclination, curvature of the rock on the tunnel wall and electrical parameters of the rock medium; Step 2.2: Estimate the space-time-frequency distribution power of electromagnetic waves in the mine using the following formula: Step 2.3: Based on the shortest ignition time Δt and the corresponding minimum ignition average power threshold P in the flammable and explosive environment threshold , estimate the safety factor S(f,t,x,y,z) of the electromagnetic wave power radiated by the mine electromagnetic wave at time point t, frequency f, and coordinates (x,y,z). The calculation formula of S(f,t,x,y,z) is as follows: Step 2.4, use the time domain and space domain to interpolate the electromagnetic wave power safety factor S(f,t,x,y,z). When S(f,t,x,y,z)≥1, it means that there is a risk of electromagnetic radiation at this time. Establish a five-dimensional distribution parameter table of unsafe electromagnetic radiation in the space-time-frequency domain of mines, and record the (f,t,x,y,z) parameters corresponding to the risky S(f,t,x,y,z) in the five-dimensional distribution parameter table of unsafe electromagnetic radiation in the space-time-frequency domain of mines. The table uses its three-dimensional centroid coordinates and area radius for description; the format of the five-dimensional distribution parameter table is as follows: Step 3, the phase of defining and publishing the maximum transmission power safety threshold of all wireless devices: the electromagnetic radiation security base station constructs a domain-time-frequency domain mapping table for unsafe electromagnetic radiation equipment in the mine, iteratively evaluates and defines the maximum safe transmission power of wireless devices that radiate electromagnetic waves at unsafe time-frequency based on the link quality priority rule. Since the safety threshold of each wireless device is different, a time-frequency configuration table of the maximum transmission power safety threshold of all wireless devices within the coverage area is established to record the corresponding safety configuration information of each wireless device. The configuration table is periodically refreshed and broadcast in the safety power configuration signaling of the electromagnetic radiation security base station according to the preset requirements; Step 3.1: Based on step 1 and step 2.4, establish a mine unsafe electromagnetic radiation device domain-time-frequency domain mapping table to check for wireless devices that radiate electromagnetic waves at unsafe times and frequencies, and use the electromagnetic radiation weighted matching value Dan to mark risky wireless devices. The device domain-time-frequency domain mapping table format is as follows: The unsafe time range in the table [t s ,t o ] and unsafe frequency range [f d ,f u ] is the time and frequency range in the space-time-frequency domain five-dimensional distribution parameter table of unsafe electromagnetic radiation in the mine; if the working time of the wireless device meets t s ≤t≤t o In the unsafe frequency band f d ≤f≤f u If it radiates electromagnetic waves, it can be judged as a risky device, and the marked Dan value is set to 1. Otherwise, it is a safe device and the Dan value is 0. Step 3.2: Establish and initialize the wireless device maximum transmission power safety threshold time-frequency configuration table: The wireless device maximum transmission power safety threshold time-frequency configuration table contains the wireless device ID number, mine unsafe electromagnetic radiation time, frequency, wireless device maximum transmission power safety threshold, the format is as follows: The initial values ​​of the time range and frequency in the wireless device maximum transmission power safety threshold time-frequency configuration table are set as follows: if the wireless device is always a safe device, its value is the longest valid time range specified by the safety power configuration signaling and the frequency at which the wireless device can operate; otherwise, the time range and frequency of the wireless device are the time range and frequency corresponding to the mine unsafe electromagnetic radiation equipment domain-time-frequency domain mapping table, and the initial value of the maximum transmission power safety threshold in the wireless device maximum transmission power safety threshold time-frequency configuration table is the maximum transmission power of the wireless device; Step 3.3: Due to the uneven spatial distribution of electromagnetic waves, the areas with strong electromagnetic fields in the electromagnetic safety protection zone are relatively dangerous, while the areas with weak electromagnetic fields are relatively safe. Therefore, the average radiation power P of each risk device radiating electromagnetic waves at each unsafe time-frequency in the unsafe area is compared. j , where j represents the ID number of the risky device; then the maximum transmit power safety threshold of the risky device is evaluated based on the link quality priority rule, P j The calculation method is as follows: represents the electromagnetic radiation complex power of the jth risk device, calculated according to the method in step 2.1, The initial value is the value generated by the j-th risk device transmitting at maximum power; The method for defining the maximum safe power threshold of risky devices based on the link quality priority rule is as follows: Step 3.3.1: Calculate according to the above formula and based on the average radiation power P of the risk equipment j Sort the risk devices in descending order, P j The largest devices have the best link quality; Step 3.3.2, based on the data collected in step 1, query the adjustable transmit power value of the risk device with the best link quality, reduce its transmit power by one level, and refresh the transmit power safety threshold in the wireless device maximum transmit power safety threshold time-frequency configuration table; Step 3.3.3, using the modeling and measurement calculation method of steps 2.1 to 2.3, the transmission parameters of all wireless devices are set according to the data of the frequency configuration table of the maximum transmission power safety threshold of the wireless device, and the electromagnetic wave radiation safety factor S (f, t, x, y, z) under the unsafe time-frequency-area of ​​the mine is iteratively evaluated; Step 3.3.4: If S(f, t, x, y, z) ≥ 1, re-execute steps 3.3.1 to 3.3.3 according to the current wireless device maximum transmission power safety threshold frequency configuration table data until all connected wireless devices meet S(f, t, x, y, z) < 1, that is, the electromagnetic radiation risk disappears; Step 4, wireless device transmit power dynamic adjustment stage: each wireless device dynamically adjusts its transmit power within a specified safe power range within different time and frequency ranges according to the received wireless device maximum transmit power safety threshold time-frequency configuration table.

2. The method for dynamically controlling the transmission power of wireless devices based on mine electromagnetic radiation safety according to claim 1 is characterized in that: The step 1 is specifically as follows: Step 1.1, two electromagnetic radiation security base stations send safety power configuration signaling to the wireless device through wireless broadcasting, and the signaling defines the effective time of the wireless device maximum transmission power safety threshold time-frequency configuration table to be released; Step 1.2, the wireless devices that receive the signaling feed back their own electromagnetic radiation data tables to the electromagnetic radiation security base station. The contents of the electromagnetic radiation data table include the ID number of the wireless device, the adjustable value of the transmission power, the absolute position coordinates, the frequency of the electromagnetic signal planned to be transmitted within the effective time, and the absolute length of time spent; Step 1.3: The two electromagnetic radiation security base stations share the electromagnetic radiation data tables of wireless devices received by each other in a wired manner.

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