Mine UWB positioning system time synchronization method, system and device

Abstract

The invention discloses a mine UWB positioning system time synchronization method, system and device, and the method comprises the steps: a UWB positioning label transmits a first data message for time synchronization, receives a second data message of a wired UWB positioning base station in a coverage range, updates a local clock based on a highest credibility calibration value in the second data message, and transmits a third message, and at least one wired UWB positioning base station sends a fourth message in a set time slot of the positioning period, and the wireless UWB positioning base stations synchronously update the clock credibility calibration value and the clock value based on the cascade codes. According to the invention, the mobile tag is used as a synchronization medium, credibility calibration and dynamic cascade coding are combined, and a calibration value is periodically reset to suppress crystal oscillator errors, so that a mine underground comprises a wired UWB positioning base station and a wireless UWB positioning base station; and the problem of difficult synchronization caused by insufficient signal coverage between base stations in a mine environment, dynamic property of wireless base stations and clock drift in dynamic change and mining disturbance characteristic scenes is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of underground mine positioning, and in particular to a time synchronization method, system and device for a mine UWB positioning system. Background Art

[0002] The underground mine environment is complex, and it is necessary to accurately locate personnel, equipment and vehicles in real time to ensure underground safety. The existing UWB positioning technology relies on fixed-deployed wired base stations. Each UWB positioning base station communicates with the upper computer server through connection methods such as fiber optic ring network or RS-485, and uploads the ranging information to the server to achieve time synchronization: that is, the underground precise positioning adopts UWB positioning technology. UWB positioning base stations are arranged at certain intervals underground. Personnel, vehicles or equipment carry UWB positioning tags. The distance between the UWB positioning base station and the UWB positioning tag is accurately calculated by measuring the flight time of the pulse signal. The coordinates of the UWB positioning base station are known. According to the accurate distances between the UWB positioning tag and multiple UWB positioning base stations, the coordinates of the UWB positioning tag can be accurately calculated.

[0003] However, the underground mine mining scenario has the characteristics of dynamic change and mining disturbance. Dynamic changes include: continuously driving the roadway forward to mine deep ore bodies, or according to the mine mining plan and schedule, operating in spatial range 1 during time period A, adjusting to spatial range 2 during time period B, and possibly returning to spatial range 1 during time period C; Disturbance such as: using explosive blasting in mine mining, which has strong destructive effects on equipment within a certain range of the blasting position. Due to the dynamic change and mining disturbance characteristics of the underground mine mining scenario, the existing positioning technology has the following defects in this application scenario: 1. Due to the long distance between wired base stations, wired UWB positioning base stations usually cannot receive UWB signals from each other, and it is impossible to complete time synchronization between base stations in a mode similar to indoor positioning; 2. Even after introducing wireless base stations, there is a series connection mode between wireless UWB positioning base stations and wired UWB positioning base stations, and the positions of wireless UWB base stations are dynamic and uncertain. It is difficult to synchronize the time between wired UWB positioning base stations and wireless UWB positioning base stations, and between wireless UWB base stations due to insufficient dynamic expansion ability of the dynamic change of the tag position; 3. The crystal oscillator error causes the clock drift to accumulate errors and generate time deviation, making it difficult to synchronize.

[0004] In the related technology, UWB positioning base stations are dynamically added as wireless UWB positioning base stations in areas that need dynamic expansion. However, after introducing wireless UWB positioning base stations, the time between wireless UWB positioning base stations and between wireless UWB positioning base stations and wired UWB positioning base stations is not synchronized. Therefore, there is an urgent need for a time synchronization method for a UWB positioning system that adapts to the dynamic scenario of underground mine mining and resists interference. Summary of the Invention

[0005] The object of the present invention is to solve the deficiencies existing in the above-mentioned prior art, and provide a time synchronization method, system and device for a mine UWB positioning system, which uses a mobile tag as a synchronization medium, combines credibility calibration with dynamic cascade coding, and periodically resets the calibration value to suppress the crystal oscillator error, so as to achieve efficient time synchronization in the scenario of a mine underground including wired UWB positioning base stations and wireless UWB positioning base stations.

[0006] The technical solution adopted by the present invention is as follows: A time synchronization method for a mine UWB positioning system, the synchronization method is based on a UWB positioning system, the UWB positioning system includes a wired UWB positioning base station, a wireless UWB positioning base station and a UWB positioning tag, and the UWB positioning tag communicates with the wireless positioning base station through UWB wireless signals (this wireless signal communication method is a prior art, and this embodiment does not elaborate on the communication connection method and information transmission method); the UWB positioning tag communicates with the wired positioning base station through UWB wireless signals; the wireless positioning base station communicates with the wired positioning base station through UWB wireless signals; the wired positioning base stations communicate with each other through optical fiber, RS-485 or CAN bus, etc. (this communication method is a prior art, and this embodiment does not elaborate on the communication connection method and information transmission method). The method includes: The UWB positioning tag sends a first data packet for time synchronization, and the first data packet carries the current clock value and the current clock credibility calibration value of the UWB positioning tag; Receive a second data packet from a wired UWB positioning base station within the coverage range, and the second data packet carries the current clock value and the current clock credibility calibration value of each wired UWB positioning base station; Update the current clock value and the current clock credibility calibration value of the UWB positioning tag based on the highest credibility calibration value in the second data packet, and send a third packet to synchronize the clock credibility calibration value and the clock value of each wired UWB positioning base station; At least one wired UWB positioning base station sends a fourth packet carrying the clock credibility calibration value and the clock value to the wireless UWB positioning base station at a set time slot in the positioning cycle; Between each wireless UWB positioning base station, the clock credibility calibration value and the clock value are synchronously updated along the direction from near to far from the wired UWB positioning base station based on cascade coding; the cascade coding is determined based on the distance relationship between each wireless UWB positioning base station and the wired UWB positioning base station, and the cascade coding decreases by 1 every time it is synchronized.

[0007] Further, the second data packet includes the clock value and the credibility calibration value of each wired UWB positioning base station, and the UWB positioning tag only selects the wired UWB positioning base stations with credibility higher than itself for synchronization.

[0008] Further, the specified time slot is a pre-allocated time slot within a positioning cycle. If the clock of the UWB positioning tag deviates from the time slot, the time synchronization request is calculated to be re-initiated by the tag, and the synchronization is delayed until the next cycle.

[0009] Further, it is configured to execute the method according to any one of claims 1-4.

[0010] See Figure 6 , the present invention also provides a time synchronization device 1 based on a mine UWB positioning system, including: A sending module, configured to send a first data packet for time synchronization, where the first data packet carries the current clock value and the current clock reliability calibration value of the UWB positioning tag; A receiving module 1, configured to receive a second data packet of a wired UWB positioning base station within the coverage range, where the second data packet carries the current clock value and the current clock reliability calibration value of each wired UWB positioning base station; A calculation module, configured to update the current clock value and the current clock reliability calibration value of the UWB positioning tag based on the highest reliability calibration value in the second data packet, and send a third packet to synchronize the clock reliability calibration value and the clock value of each wired UWB positioning base station; A sending-down module, configured to at least one wired UWB positioning base station send a fourth packet carrying the clock reliability calibration value and the clock value to the wireless UWB positioning base station in a set time slot of the positioning cycle; A receiving module 2, configured to synchronize and update the clock reliability calibration value and the clock value among each wireless UWB positioning base station along the direction from near to far from the wired UWB positioning base station based on concatenated coding; the concatenated coding is determined based on the distance relationship between each wireless UWB positioning base station and the wired UWB positioning base station, and the concatenated coding decreases by 1 each time synchronization occurs.

[0011] The present invention also provides a mine UWB positioning system, where the UWB positioning system includes a wired UWB positioning base station, a wireless UWB positioning base station, and a UWB positioning tag, and the UWB positioning system is configured to execute a time synchronization method.

[0012] The present invention also provides a storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for executing time synchronization are realized.

[0013] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method for executing the claim of time synchronization are realized.

[0014] The present invention has the following advantages: 1. The present invention uses mobile tags as a synchronization medium to transmit synchronization signals, covering blind areas and adapting to dynamic scenarios.

[0015] 2. By dynamically screening the optimal clock source based on credibility and selecting the calibration value and clock value with the highest credibility for synchronization, and combining cascade coding to achieve efficient multi-hop synchronization of wireless base stations, the dynamic expansion ability is increased, and time synchronization under dynamically changing positions is achieved.

[0016] 3. Periodically reset the calibration value, and the timeout reset mechanism suppresses the crystal oscillator error, realizing long-term synchronization accuracy maintenance in the mine underground environment, suppressing the cumulative error of clock drift caused by the crystal oscillator error to generate time deviation, and achieving accurate time synchronization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flowchart of the time synchronization method of the present invention; Figure 2 It is a schematic flowchart of the time synchronization method of Embodiment 1 of the present invention; Figure 3 It is a schematic diagram of the mine roadway topology and base station deployment of Embodiment 3 of the present invention; Figure 4 It is a schematic diagram of the attribute information of each positioning base station in the UWB positioning system in Scenario 1 of Embodiment 3 of the present invention; Figure 5 It is a schematic diagram of the attribute information of each positioning base station in the UWB positioning system in Scenario 2 of Embodiment 3 of the present invention; Figure 6 It is a schematic diagram of the time synchronization device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The content of the present invention will be further described below in conjunction with the accompanying drawings of the specification and embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application. Embodiment 1

[0019] The tag triggers the synchronization of the wired base station: After the tag enters the system, it broadcasts a synchronization request (the first message), and the wired base stations within the coverage range return their own clock and credibility values (the second message); the tag selects the highest credibility value to update the local clock and triggers the synchronization of the wired base station at the specified time slot (the third message); the wired base station sends the fourth message in the wireless synchronization time slot, and after receiving it, the wireless base station updates the clock and generates cascade coding.

[0020] In the embodiment of the present application, the clock value and the clock reliability calibration value of the UWB positioning tag are first updated based on the wired UWB positioning base station, and then synchronization is performed between the base stations based on the updated clock value and the clock reliability calibration value. This can not only solve the time synchronization between the wired UWB positioning base stations in the scenario where the UWB signal cannot be received, but also achieve the time synchronization between the wired UWB positioning base station and the wireless UWB positioning base station, as well as between the wireless UWB positioning base stations in the scenario with dynamics and uncertainties, thus better meeting the time synchronization requirements of the UWB positioning system.

[0021] Refer to Figure 1 , a method for time synchronization of a mine UWB positioning system, characterized in that the UWB positioning system includes a wired UWB positioning base station, a wireless UWB positioning base station and a UWB positioning tag, and the method includes: The UWB positioning tag sends a first data packet for time synchronization, and the first data packet carries the current clock value and the current clock reliability calibration value of the UWB positioning tag; Receive the second data packet of the wired UWB positioning base station within the coverage range, and the second data packet carries the current clock value and the current clock reliability calibration value of each wired UWB positioning base station; here, the UWB positioning tag can have an initial clock value and a reliability calibration value. The wired UWB positioning base station can be understood as a UWB positioning base station with a fixed position, and its attribute information can include: clock value, clock reliability, clock reliability calibration value and clock reliability calibration time. Among them, the clock value on the positioning tag or the positioning base station can be understood as the timing time corresponding to the local crystal oscillator circuit; the clock reliability is used to represent the reliability of the timing time. In this embodiment, a predetermined clock reliability is configured on the wired UWB positioning base station, and it is agreed that the closer the base station is to the entrance, the greater the clock reliability; the clock reliability calibration value is used to dynamically represent the corresponding clock reliability. For example, if the clock value of this base station has been synchronized by another base station A, the clock reliability calibration value is replaced with the clock reliability corresponding to that base station A; the clock reliability calibration time represents the time of the aforementioned replacement (i.e., calibration).

[0022] It should be noted that after the UWB positioning tag accesses the UWB positioning system, it can send a first message to the surrounding UWB wired positioning base stations. The first message carries the local clock value and the initial credibility calibration value of the UWB positioning tag (for example, it can be 0), and the current clock value and the current clock credibility calibration value of the UWB positioning tag can be updated based on the second message returned by the wired UWB positioning base station. Here, from the second messages returned by multiple wired UWB positioning base stations, the message with the highest clock credibility can be selected, and the clock credibility calibration value of this message can be used as the local clock credibility calibration value, and the clock value of this message can be used as the local clock value. In this way, the clock value with the highest credibility in the current area can be obtained based on the interaction with the wired UWB positioning base station.

[0023] Update the current clock value and the current clock credibility calibration value of the UWB positioning tag based on the highest credibility calibration value in the second data packet, and send a third message to synchronize the clock credibility calibration values and clock values of each wired UWB positioning base station; At least one wired UWB positioning base station updates its own clock credibility calibration value and clock value based on the received third message, and sends a fourth message to the wireless UWB positioning base station at the set time slot of the positioning cycle; Among them, each UWB positioning base station determines the updated clock credibility calibration value and clock value based on the maximum of the local clock credibility calibration value and the clock credibility calibration value in the received message, and the fourth message carries the updated clock credibility calibration value and clock value of the wired UWB positioning base station.

[0024] Here, after the UWB positioning tag updates its attribute information, due to its mobility, it can move to other areas and can send a third message based on its own positioning time slot to transfer its clock credibility calibration value and current clock value to the positioning base stations within the communication range. After receiving the third message, the wired UWB positioning base station can update the local attribute information (that is, time synchronization between the wired UWB positioning base stations can be achieved), and send a fourth message to the wireless UWB positioning base station at the set time slot of the positioning cycle, thereby realizing the update of the attribute information of the wireless UWB positioning base station (that is, time synchronization between the wired UWB positioning base station and the wireless UWB positioning base station can be achieved).

[0025] Among the wireless UWB positioning base stations, the clock credibility calibration values and clock values are synchronously updated along the direction from near to far from the wired UWB positioning base station based on the concatenated coding; the concatenated coding is determined based on the distance relationship between each wireless UWB positioning base station and the wired UWB positioning base station, and the concatenated coding decreases by 1 every time it is synchronized. Among them, the concatenated coding is determined based on the distance relationship between each wireless UWB positioning base station and the wired UWB positioning base station.

[0026] It is understandable that the wireless UWB positioning base stations can also continue to perform time synchronization based on the wireless cascading relationship. For example, after the first-level cascaded wireless UWB positioning base station synchronizes time with the wired UWB positioning base station, it can send a fifth message to the second-level cascaded wireless UWB positioning base station. The fifth message carries the updated credibility calibration value and clock value. In this way, the second-level cascaded wireless UWB positioning base station can perform time synchronization and continue to send a sixth message downward, and so on, until the time synchronization of the terminal wireless UWB positioning base station is achieved.

[0027] Exemplarily, the method further includes: The UWB positioning tag determines whether it is located in its corresponding positioning time slot based on the current clock value. If not, it determines to enter the positioning time slot corresponding to itself in the next positioning cycle, updates the local clock credibility calibration value and clock value, and sends the third message.

[0028] Here, the UWB positioning tag needs to send the third message in its corresponding positioning time slot, that is, multiplex the time synchronization request based on the positioning time slot. If it is determined that the current clock value does not belong to its corresponding positioning time slot, it can update the local clock credibility calibration value and clock value in the positioning time slot corresponding to the next positioning cycle, and send the third message to the wired UWB positioning base station.

[0029] Exemplarily, the UWB positioning tag and the wired UWB positioning base station also record an update value representing the update time, and the method further includes: The UWB positioning tag and / or the wired UWB positioning base station determine that the interval duration from the update value reaches the set interval duration, and then reset the local clock credibility calibration value and clock value to the initial values.

[0030] It should be noted that the UWB positioning tag and the wired UWB positioning base station can also introduce an update value (i.e., the clock credibility calibration time), and determine whether the updated attribute information is valid based on this update value. If it is determined that the update interval duration reaches the set interval duration, the local clock credibility calibration value and clock value are reset to the initial values. Embodiment 2

[0031] Wireless base station cascading synchronization and timeout reset mechanism: The wireless base station with cascade number 1 receives the fourth message from the wired base station, updates the clock and broadcasts the fifth message; the next-level wireless base station (cascade number 2) updates the clock and decrements the number after receiving it until the terminal base station completes synchronization.

[0032] If the tag or the base station does not update the clock within ΔT time, the credibility calibration value is reset to the initial value (set to 0 for the tag and the preset credibility for the wired base station) to avoid the accumulation of crystal oscillator errors.

[0033] Reference Figure 2 , the time synchronization method in this embodiment includes: 1) Occupancy time allocation of tags in the mine UWB positioning system The mine UWB positioning system includes a wired UWB positioning base station, a wireless UWB positioning base station, and UWB positioning tags. The wired UWB positioning base stations are connected by optical fiber or RS-485.

[0034] The attribute information of the wired UWB positioning base station includes: base station clock, clock credibility, clock credibility calibration value, and clock credibility calibration time. In the initial state, the clock credibility calibration value is equal to the clock credibility, and the clock credibility calibration time is 0.

[0035] The attribute information of the wireless UWB positioning base station includes: base station clock, clock credibility calibration value, and cascade number. In the initial state, the clock credibility calibration value is 0, and the initial value of the cascade number is 255.

[0036] The attribute information of the UWB positioning tag includes: tag clock, clock credibility calibration value, and clock credibility calibration time. In the initial state, the clock credibility calibration value is 0, and the clock credibility calibration time is 0.

[0037] Due to the error in the operation of the clock oscillators of the base station and the tag, after ΔT time, the error generated by the operation of the clock oscillator will exceed the error tolerance threshold of the UWB positioning system time synchronization. Therefore, when the difference between the clock of the base station or the tag and the clock credibility calibration time is greater than ΔT, the clock credibility calibration value of the base station or the tag is reset to the initial value.

[0038] Let the positioning period of the mine UWB positioning system be T. The positioning period T is divided into M sub-periods. Among them, M - 2 sub-periods are used for the tag to range and synchronize time with the base station, one sub-period is used for the time synchronization of the wireless UWB base station, and the other sub-period is used for the transmission of the ranging results between the tag and the wireless UWB base station. Each UWB positioning tag occupies one sub-period. Let the sub-period occupied by tag i be , sub-period The start time of is .

[0039] 2) The first data packet for the positioning tag to initiate a time synchronization request When any tag i enters the mine UWB positioning system, tag i initiates the first data packet for the time synchronization request. The first data packet includes the tag clock and the clock credibility calibration value.

[0040] Let the A wired base station received the first data packet. Taking wired base station j as an example, assume the base station clock of wired base station j is , and the clock reliability calibration value is . When > , adjust the base station clock to .

[0041] 3) The second data packet for the wired positioning base station to reply to the time synchronization request The second data packets replied by wired base stations to the time synchronization request. The second data packet includes the base station clock and the clock reliability calibration value. Assume the base station with the largest clock reliability calibration value among wired base stations is

[0042] Tag i receives the second data packets replied by < wired base stations to the time synchronization request. When , adjust the clock of the positioning tag to , adjust the clock reliability calibration value of the positioning tag to

[0043] and adjust the clock reliability calibration time to the current moment. Judge whether the clock of tag i is within the time range of the sub - cycle : (1) If is within the time range of the sub - cycle , then tag i initiates the third data packet of the time synchronization instruction; (2) If is not within the time range of the sub - cycle : (2.1) When , - after time, tag i re - initiates the first data packet of the time synchronization request; (2.2) When > , +T - after time, tag i re - initiates the first data packet of the time synchronization request.

[0044] 4) The third data packet for the positioning tag to initiate the time synchronization instruction Tag i initiates the third data packet of the time synchronization instruction. The third data packet includes the tag clock of tag i and the clock reliability calibration value .

[0045] Let label i be near A wired base station receives the third data message and The base station clocks of all wired base stations are adjusted to , the base station clock credibility calibration values are adjusted to , the base station clock credibility calibration time is adjusted to the current time.

[0046] 5) The fourth data message of the wired base station initiating the time synchronization instruction At the start of the sub-period of time synchronization of the wireless UWB base station, the wired base station initiates a fourth data message of a time synchronization instruction. Taking base station j as an example, the fourth data message includes the base station clock: , the clock credibility calibration value is .

[0047] set up A wireless base station receives the fourth data message and The base station clocks of all wireless base stations are adjusted to , the clock credibility calibration values are adjusted to , the cascade numbers are all adjusted to 1.

[0048] 6) The wireless base station forwards the fifth data message of the time synchronization instruction After receiving and processing the fourth data message, the wireless base station forwards the fifth data message of the time synchronization instruction. Taking the wireless base station k as an example, the fifth data message includes the base station clock , the clock credibility calibration value is , the cascade number is .in, = , = .

[0049] set up A wireless base station receives the fifth data message and The base station clocks of all wireless base stations are adjusted to , the clock credibility calibration values are adjusted to , the cascade number increases by 1.

[0050] 7) The wireless base station further relays the data message of the time synchronization instruction After processing the fifth data message, the wireless base station further relays the data message of the time synchronization instruction. A wireless base station receives a data message of the relay forwarding time synchronization instruction: (1) Among them The cascade number of wireless base stations is greater than , adjust the base station clocks of wireless base stations to , and adjust the clock reliability calibration values to , and increase the cascade number by 1.

[0051] (2) Among them the cascade numbers of wireless base stations are less than or equal to , and

[0052] the wireless base stations ignore the data packets.

[0053] In this way, the dynamic synchronization of the clocks of the UWB positioning system based on the UWB positioning tags can be achieved. Embodiment 3

[0054] A certain underground mine uses UWB for high-precision personnel positioning. The schematic diagram of the roadway space topological relationship in the production scenario is as Figure 3 shown. Figure 3 It shows the roadway side line 1, roadway center line 2, wireless UWB positioning base station 3, and wired UWB positioning base station 4 of the roadway.

[0055] The mine UWB positioning system includes a wired UWB positioning base station, a wireless UWB positioning base station, and a UWB positioning tag. The wired UWB positioning base stations are connected by optical fiber or RS-485.

[0056] The attribute information of the wired UWB positioning base station includes: base station clock, clock reliability, clock reliability calibration value, clock reliability calibration time. In the initial state, the clock reliability calibration value is equal to the clock reliability, and the clock reliability calibration time is 0.

[0057] The attribute information of the wireless UWB positioning base station includes: base station clock, clock reliability calibration value, cascade number. In the initial state, the clock reliability calibration value is 0, and the initial value of the cascade number is 255.

[0058] The attribute information of the UWB positioning tag includes: tag clock, clock reliability calibration value, clock reliability calibration time. In the initial state, the clock reliability calibration value is 0, and the clock reliability calibration time is 0.

[0059] Due to the error in the operation of the clock oscillators of the base station and the tag, after △T time, the error generated by the operation of the clock oscillator will exceed the error tolerance threshold of the UWB positioning system time synchronization. Therefore, when the difference between the clock of the base station or the tag and the clock reliability calibration time is greater than △T, the clock reliability calibration value of the base station or the tag is reset to the initial value.

[0060] The positioning period of the mine UWB positioning system is set to 1 s. The 1-s positioning period is divided into 200 sub-periods. Among them, 198 sub-periods are used for the ranging and time synchronization between the tag and the base station, 1 sub-period is used for the time synchronization of the wireless UWB base station, and 1 sub-period is used for the transmission of the ranging results between the tag and the wireless UWB base station. Each UWB positioning tag occupies 1 sub-period. Let the sub-period occupied by tag i be , and the start time of sub-period is .

[0061] Scenario 1: At the moment of 101000, when tag 1001 enters the mine UWB positioning system, tag 1001 initiates the first data packet of the time synchronization request. The first data packet includes the tag clock of tag 1001 as 101003 and the clock credibility calibration value as 0, and the attribute information of each positioning base station in the mine UWB positioning system is as Figure 4 shown.

[0062] One wired base station 2001 near tag 1001 receives the first data packet. The base station clock of wired base station 2001 is 101005, and the clock credibility calibration value is 99, less than , and no processing is performed.

[0063] The wired base station 2001 replies with the second data packet of the time synchronization request. The second data packet includes the base station clock and the clock credibility calibration value. The base station with the largest clock credibility calibration value among the wired base stations is , which is 2001.

[0064] Tag 1001 receives the second data packet of the time synchronization request replied by the wired base station 2001, < , adjusts the clock of the positioning tag to 101005, adjusts the clock credibility calibration value of the positioning tag to 99, and adjusts the clock credibility calibration time to 101005.

[0065] The clock of tag 1001, 101005, is within the time range of sub-period . Tag 1001 initiates the third data packet of the time synchronization instruction. The third data packet includes the tag clock 101005 of tag 1001 and the clock credibility calibration value 99.

[0066] The wired base station 2001 near tag 1001 receives the third data packet, adjusts the base station clocks of the wired base station 2001 to 101005, adjusts the base station clock credibility calibration values to 99, and adjusts the base station clock credibility calibration times to the current moment.

[0067] At the start of the sub - cycle of time synchronization in the wireless UWB base station, the wired base station 2001 initiates the fourth data packet of the time synchronization instruction, and 0 wireless base stations receive the fourth data packet.

[0068] Scenario two: At time 102000, tag 1001 moves to the position as Figure 5 shown.

[0069] Tag 1001 initiates the first data packet of the time synchronization request. The first data packet includes the tag clock of tag 1001 as 102009 and the clock reliability calibration value as 99. Two wired base stations 2002 and 2003 near tag 1001 receive the first data packet. The clock reliability calibration value of wired base station 2002 is equal to 99 and no processing is done; the clock reliability calibration value of wired base station 2003 is less than 99, and the base station clock of wired base station 2003 is adjusted to 102009.

[0070] Wired base stations 2002 and 2003 reply with the second data packet of the time synchronization request. The second data packet includes the base station clock and the clock reliability calibration value. The base station with the largest clock reliability calibration value among wired base stations 2002 and 2003 is 2002.

[0071] Tag 1001 receives the second data packet of the time synchronization request replied by wired base stations 2002 and 2003, = , so no processing is done.

[0072] The clock of tag 1001 is within the time range of the sub - cycle . Tag 1001 initiates the third data packet of the time synchronization instruction. Wired base stations 2002 and 2003 near tag 1001 receive the third data packet. The base station clocks of the two wired base stations are both adjusted to 102009, the clock reliability calibration values are both adjusted to 99, and the clock reliability calibration times of the base station clocks are both adjusted to 102009.

[0073] At the start of the sub - cycle of time synchronization in the wireless UWB base station, the wired base station initiates the fourth data packet of the time synchronization instruction. Taking base station 2003 as an example, the fourth data packet includes the base station clock as 102009 and the clock reliability calibration value as 99.

[0074] Suppose two wireless base stations 3001 and 3004 receive the fourth data packet. The base station clocks of the two wireless base stations are both adjusted to 102009, the clock reliability calibration values are both adjusted to 99, and the cascade numbers are both adjusted to 1.

[0075] After receiving and processing the fourth data packet, the radio base station forwards the fifth data packet with a time synchronization instruction. Taking radio base station 3001 as an example, the fifth data packet includes a base station clock of 102009, a clock reliability calibration value of 99, and a cascade number of 1.

[0076] One radio base station 3002 received the fifth data packet, adjusted the base station clock of radio base station 3002 to 102009, adjusted the clock reliability calibration values to 99, and increased the cascade number by 1. After the increase, the cascade number is 2.

[0077] After processing the fifth data packet, radio base station 3002 further relays and forwards the data packet with the time synchronization instruction. Radio base stations 3001 and 3003 received the data packet relayed and forwarded with the time synchronization instruction: (1)Among them, the cascade number of radio base station 3003 is greater than 2. Adjust the base station clock of radio base station 3003 to 102009, adjust the clock reliability calibration values to 99, and increase the cascade number by 1. After the increase, the cascade number is 3.

[0078] (2)Among them, the cascade number of radio base station 3001 is less than or equal to 2, and radio base station 3001 ignores the data packet.

[0079] Radio base station 3003 further relays and forwards the data packet with the time synchronization instruction. At this time, only radio base station 3002 received the data packet. The cascade number of radio base station 3002 is less than or equal to 3, so radio base station 3002 ignores the data packet.

[0080] In an exemplary embodiment, the embodiment of the present application further provides a UWB positioning system, which includes a wired UWB positioning base station, a wireless UWB positioning base station, and a UWB positioning tag. The UWB positioning system is configured to execute the time synchronization method described in the embodiment of the present application.

[0081] In an exemplary embodiment, the embodiment of the present application further provides a storage medium, that is, a computer storage medium, specifically a computer-readable storage medium. For example, it includes a memory storing a computer program. The above computer program can be executed by the UWB positioning system to complete the steps described in the method of the embodiment of the present application. The computer-readable storage medium can be a ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disc, or CD-ROM, etc.

[0082] In an exemplary embodiment, the embodiment of the present application further provides a computer program product, including a computer program. The above computer program can be executed by the UWB positioning system to complete the steps described in the method of the embodiment of the present application.

[0083] It should be noted that: "first", "second", etc. are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0084] In addition, among the technical solutions described in the embodiments of the present application, they can be arbitrarily combined without conflict.

[0085] As mentioned above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A time synchronization method for a mine UWB positioning system, characterized in that, The synchronization method is based on a UWB positioning system, which includes a wired UWB positioning base station, a wireless UWB positioning base station, and a UWB positioning tag. The time synchronization method includes: The UWB positioning tag sends a first data packet for time synchronization, and the first data packet carries the current clock value and the current clock reliability calibration value of the UWB positioning tag; Receive the second data packet of the wired UWB positioning base station within the coverage area. The second data packet carries the current clock value and the current clock reliability calibration value of each wired UWB positioning base station; Based on the highest reliability calibration value in the second data packet, update the current clock value and the current clock reliability calibration value of the UWB positioning tag, and send a third packet to synchronize the clock reliability calibration value and the clock value of each wired UWB positioning base station; At least one wired UWB positioning base station sends a fourth packet carrying the clock reliability calibration value and the clock value to the wireless UWB positioning base station at a set time slot in the positioning cycle; Among the wireless UWB positioning base stations, the clock reliability calibration value and the clock value are synchronously updated in the direction from near to far from the wired UWB positioning base station based on the concatenated coding; the concatenated coding is determined based on the distance relationship between each wireless UWB positioning base station and the wired UWB positioning base station, and the concatenated coding decreases by 1 every time it is synchronized.

2. The method according to claim 1, wherein The second data packet contains the clock value and the reliability calibration value of each wired UWB positioning base station, and the UWB positioning tag only selects the wired UWB positioning base stations with higher reliability than itself for synchronization.

3. The method according to claim 1, wherein The specified time slot is a pre-allocated time slot within the positioning cycle. If the clock of the UWB positioning tag deviates from the time slot, calculate that the tag reissues a time synchronization request and delay it until the next cycle for synchronization.

4. A time synchronization device for a mine UWB positioning system, characterized in that, Configured to execute the method according to any one of claims 1-4.

5. A time synchronization device based on a mine UWB positioning system, characterized in that, Includes: A sending module, configured to send a first data packet for time synchronization, and the first data packet carries the current clock value and the current clock reliability calibration value of the UWB positioning tag; A receiving module 1, configured to receive the second data packet of the wired UWB positioning base station within the coverage area. The second data packet carries the current clock value and the current clock reliability calibration value of each wired UWB positioning base station; A calculation module, configured to update the current clock value and the current clock reliability calibration value of the UWB positioning tag based on the highest reliability calibration value in the second data packet, and send a third packet to synchronize the clock reliability calibration value and the clock value of each wired UWB positioning base station; A sending-down module, configured to at least one wired UWB positioning base station send a fourth packet carrying the clock reliability calibration value and the clock value to the wireless UWB positioning base station at a set time slot in the positioning cycle; A receiving module 2, configured to synchronously update the clock reliability calibration value and the clock value in the direction from near to far from the wired UWB positioning base station among the wireless UWB positioning base stations based on the concatenated coding; the concatenated coding is determined based on the distance relationship between each wireless UWB positioning base station and the wired UWB positioning base station, and the concatenated coding decreases by 1 every time it is synchronized.

6. A mine UWB positioning system, characterized in that, The UWB positioning system includes a wired UWB positioning base station, a wireless UWB positioning base station, and a UWB positioning tag, and the UWB positioning system is configured to execute the method according to any one of claims 1 to 4.

7. A storage medium, on which a computer program is stored, characterized in that, When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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