Data interaction and initialization method of indoor positioning system

Abstract

The invention discloses a data interaction and initialization method of an indoor positioning system, and relates to the technical field of indoor positioning. According to the method, a dual-band communication architecture is constructed, ranging data between base stations and between the base stations and a moving target are transmitted in a main frequency mode, and configuration parameters, control instructions and moving target auxiliary information are transmitted in a low frequency mode; the master base station sends a startup signal to the upper computer after being started, generates synchronization information with a synchronization identifier and broadcasts the synchronization information to the slave base station after receiving a configuration instruction of the upper computer, and the slave base station feeds back, confirms and forwards in a relay manner after completing configuration to form an initialized base station network; and the moving target searches a main base station signal in a low-frequency mode, sends a registration request, and establishes a communication link with the main base station and the slave base station after receiving a response containing the identifier of the main base station, thereby completing system initialization. Through dual-band separation transmission and a standardized initialization process, data interference is reduced, parameter synchronization efficiency is improved, and stable operation of a positioning system is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of indoor positioning technology, in particular to a data interaction and initialization method of an indoor positioning system. BACKGROUND

[0002] In the prior art, an indoor positioning system often uses a single frequency band for communication, and various types of data such as ranging data between base stations, device configuration parameters, and mobile target auxiliary information are mixed and transmitted synchronously. Since the ranging data has very high transmission accuracy requirements, spread spectrum communication is often used, while the configuration parameters and auxiliary information have outstanding transmission real-time requirements, and the two types of data are prone to mutual interference when transmitted by a single frequency band, resulting in an increase in ranging data transmission error rate or an increase in auxiliary information delay, affecting positioning accuracy and system response speed.

[0003] At the same time, during system initialization, there is a lack of standardized interaction logic between the master base station, slave base station, mobile target, and host computer, and parameter synchronization relies on manual configuration or simple broadcasting, which is prone to problems such as inconsistent parameters and delayed link establishment, resulting in a long time for system startup, and even affecting subsequent positioning stability due to incomplete initialization. SUMMARY

[0004] To solve the technical problems existing in the prior art, the present application provides a data interaction and initialization method of an indoor positioning system.

[0005] The technical solution adopted by the present application is: a data interaction and initialization method of an indoor positioning system, comprising the following steps: Step 1, a dual-band communication architecture is constructed, which includes a main frequency mode and a low frequency mode, the main frequency mode is used to transmit ranging data between the master base station and the slave base station, and ranging data between the master base station and the slave base station and the mobile target, and the low frequency mode is used to transmit configuration parameters, control instructions, and mobile target auxiliary information; Step 2, after the master base station is started, it sends a power-on signal to the host computer based on the low frequency mode of the dual-band communication architecture; Step 3, after the host computer receives the power-on signal, it generates a configuration instruction containing running parameters and sends it to the master base station through the low frequency mode; Step 4, the master base station receives and analyzes the configuration instruction, completes its own parameter configuration, generates synchronization information with a synchronization identifier, and broadcasts it to the slave base station through the low frequency mode; Step 5, the slave base station receives the synchronization information, analyzes the synchronization identifier and configuration instruction therein, completes its own parameter configuration, returns an acknowledgement information to the master base station, and relays and forwards the synchronization information until all slave base stations in the system complete the configuration, forming an initialized base station network; Step 6, after the mobile target is started, search for the master base station signal in the initialized base station network through the low frequency mode, and send a registration request containing its own identification; Step 7, after the master base station receives the registration request, return a registration response containing the identification of the master base station; Step 8, the mobile target receives the registration response, stores the identification of the master base station, establishes a communication link with the master base station and the slave base station based on the dual-band communication architecture, and completes the system initialization.

[0006] Preferably, in step 1, when the master base station transmits the ranging data, the master base station and the slave base station perform multiple independent measurements on the same distance and take the average, and the master base station and the slave base station respectively initiate the ranging process and perform cross verification, and the ranging data transmission is completed through bidirectional data interaction.

[0007] Preferably, in step 4, the synchronization identification is a unique sequence that is sequentially increased, and the version information of the configuration instruction is associated; the synchronization information contains the configuration instruction and the synchronization identification.

[0008] Preferably, in step 5, when the slave base station relays and forwards the synchronization information, the synchronization identification remains unchanged; the confirmation information returned by the slave base station to the master base station contains its own identification and a configuration completion identification; when the number of confirmation information accumulated by the master base station is consistent with the total number of slave base stations preset by the system, it is determined that the base station network initialization is completed.

[0009] Preferably, in step 6, the identification of the mobile target starts with a mobile target preset character, contains the same area code and mobile target unique serial number as the master base station; in step 7, the identification of the master base station starts with a base station preset character, contains the area code and the base station unique serial number, wherein the mobile target preset character and the base station preset character are different characters, and the mobile target unique serial number and the base station unique serial number belong to independent numbering sequences.

[0010] Preferably, in step 8, the communication link established by the mobile target with the master base station and the slave base station includes a main frequency channel and a low frequency channel, wherein the main frequency channel is used for transmitting ranging data, and the low frequency channel is used for transmitting mobile target auxiliary information; the mobile target periodically sends a link detection frame through the low frequency channel, and the master base station and the slave base station return a response frame after receiving it.

[0011] Preferably, in step 1, the mobile target auxiliary information includes real-time attitude information and a distress signal; the real-time attitude information is periodically synchronized based on the timestamp of the master base station main frequency ranging data packet, and the transmission timing is calibrated once for every received main frequency ranging data; after the distress signal is triggered, the transmission of non-emergency information is suspended until the distress signal is sent.

[0012] Preferably, in step 1, the communication data frame of the main frequency mode comprises a frame header, a synchronization word, frame application data, and a frame trailer; the frame application data includes a scrambling code, a packet type, a destination address, a source address, a data length, a ranging identifier, and a check field; the ranging identifier is used to distinguish between the first ranging and the retry ranging.

[0013] Preferably, in step 8, after the mobile target establishes a communication link with the master base station and the slave base station, when the mobile target transmits ranging data to the master base station through the main frequency mode, the synchronization additional data confidence identifier is set based on the output value of the signal strength register built-in the tag: when the signal strength is lower than the preset threshold, the confidence identifier is low, otherwise it is high. After the master base station receives the ranging data, for the ranging data with a confidence identifier lower than the preset threshold for three or more times, the master base station starts a sliding window filtering process, and replaces the abnormal value with the mean value of the first five valid ranging data in the window. If the deviation of a single ranging data from the previous three normal ranging data exceeds the preset proportion, and the confidence identifier of the data is low, the master base station determines that it is a transient interference data and discards it, and fills in the ranging value at this time based on the historical trajectory trend prediction. When the confidence identifier of the mobile target is high for three times, and the preset normal transmission condition is met, the master base station stops the prediction filling and restores the real-time ranging data.

[0014] Preferably, if the deviation of the real-time ranging data received by the master base station from the historical normal trajectory continuously exceeds the preset range, the master base station sends a signal distortion collection instruction to the mobile target through the low frequency mode. The mobile target collects the distortion parameters of the current main frequency signal based on the signal distortion collection instruction, including the signal phase offset and the spectral purity, and returns the distortion parameters to the master base station in the feedback frame of the low frequency mode. The master base station extracts the distortion parameters in the feedback frame, and matches them with the preset environmental interference feature library. If the matching is successful and the duration reaches the preset threshold, it is determined that there is systematic interference. The master base station calls the pre-stored calibration coefficient corresponding to the systematic interference to perform secondary correction on the ranging data after the sliding window filtering or the transient interference data discarding process. After the secondary correction, the master base station coordinates at least three different slave base stations to perform synchronous ranging on the same mobile target, calculates the variance of the corrected ranging data returned by each slave base station, and if the variance is less than the preset threshold, takes the mean value corresponding to the variance as the valid ranging data; if the variance exceeds the preset threshold, the master base station suspends the positioning output of the mobile target. When the distortion parameters fed back by the mobile target fail to match the interference feature library, the master base station stops the secondary correction and restores the processing based on the real-time ranging data.

[0015] The beneficial effects of the present application are at least one of the following: by constructing a dual-band communication architecture, the ranging data between base stations and between base stations and mobile targets is transmitted through the main frequency mode, and the configuration parameters, control instructions and mobile target auxiliary information are transmitted through the low frequency mode, realizing the separate transmission of different types of data, which helps to reduce the mutual interference caused by mixed transmission of data in a single frequency band, thereby improving the transmission accuracy of ranging data and the timeliness of auxiliary information transmission to a certain extent.

[0016] During the system initialization process, through the instruction interaction between the master base station and the upper computer, the synchronization information broadcast and relay forwarding from the master base station to the slave base station, the confirmation feedback of the slave base station, and the standardized process of the mobile target registration after the completion of the base station network initialization, it is beneficial to promote the parameter synchronization between the master base station, the slave base station and the mobile target, reduce the inconsistency of parameters, and at the same time, to a certain extent, shorten the system startup time and improve the stability of system initialization. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The flowchart of the method of the present application is shown. DETAILED DESCRIPTION

[0018] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0019] It should be noted that the present application is applicable to non-line-of-sight (NLOS) scenarios and complex environments with multipath effects. The non-line-of-sight scenario refers to a communication scenario in which there is no direct line of sight between the base station and the mobile target, and there are barriers such as ruins, steel structures, smoke, obstacles, etc.

[0020] Multipath effect refers to the fact that in addition to the direct path, there are multiple propagation paths formed by reflection and scattering of signals from the transmitting end to the receiving end through obstacles such as ruins, metal components, smoke particles, etc., resulting in the receiving end receiving direct signals and multipath signals at the same time, which superimpose to produce ranging errors, and is one of the factors affecting positioning accuracy in indoor rescue scenarios.

[0021] Considering that the traditional indoor positioning system uses a single frequency band for transmission, resulting in mutual interference between ranging data and auxiliary information; the initialization process lacks standardized design, the base station network building efficiency is low and the coverage is not complete; the mobile target access has no standardized process, the communication link stability is poor, and it cannot adapt to the positioning needs of complex scenarios such as indoor rescue, the present embodiment provides a data interaction and initialization method for an indoor positioning system, as shown in Figure 1 The method comprises the following steps: Step 1, constructing a dual-band communication architecture, the dual-band communication architecture includes a main frequency mode and a low frequency mode, the main frequency mode is used to transmit ranging data between the main base station and the slave base station, ranging data between the main base station and the slave base station and the mobile target, the low frequency mode is used to transmit configuration parameters, control instructions and mobile target auxiliary information.

[0022] It should be noted that the dual-band communication architecture refers to the system using two different frequency bands of communication mode at the same time, the main frequency mode and the low frequency mode, which respectively bear different types of data transmission.

[0023] The main frequency mode refers to the communication mode of higher frequency band, such as 2.4GHz, which has the characteristics of fast transmission rate, high precision, wide spread spectrum bandwidth and strong electromagnetic wave diffraction ability.

[0024] For example, the main frequency mode uses CSS technology to achieve, which is based on chirp code for ranging signal modulation and demodulation, and can effectively resist multipath effect and realize high-precision ranging. Chirp code refers to the spread spectrum code whose frequency changes linearly with time. The time-frequency coupling characteristics of chirp code enable the receiver to accurately extract the signal propagation time (ToF) through correlation operation, and have good resolution ability to multipath reflection signal, which can separate direct signal and delayed multipath signal, so it has the characteristics of fast transmission rate, high ranging precision, strong electromagnetic wave diffraction ability and outstanding multipath suppression ability, which can effectively reduce the ranging error caused by multipath effect.

[0025] The low frequency mode refers to the communication mode of lower frequency band, such as 433MHz, which has the characteristics of strong penetration ability and good anti-interference ability.

[0026] The inter-base station ranging data refers to the measurement data used to calculate the distance between the main base station and the slave base station; the ranging data between the base station and the mobile target refers to the measurement data used to calculate the distance between the main base station, the slave base station and the mobile target, such as the positioning tag carried by the rescue personnel and the signal transmitter of the trapped personnel.

[0027] The configuration parameters refer to the parameters used to set the running state of the base station and the mobile target, such as transmission power, communication period, chirp code type, CSS spread spectrum bandwidth, etc.; the control instructions refer to the operation commands sent by the host computer or the main base station to other devices, such as starting ranging, switching mode, etc. The mobile target auxiliary information refers to the non-ranging data generated by the mobile target, such as the vital signs of the rescue personnel, the distress signal, etc.

[0028] In a specific implementation process, the system presets the frequency band parameters of the main frequency mode and the low frequency mode, the main frequency mode uses the 2.4 GHz frequency band, configures the CSS technical parameters, sets the bandwidth to 80 MHz, generates a ranging signal through chirp code modulation, and is specially used for transmitting ranging data between base stations and between base stations and mobile targets; the low frequency mode uses the 433 MHz frequency band, and sets the bandwidth to 250 kHz, which is used for transmitting configuration parameters, control instructions and mobile target auxiliary information. The two modes work independently, and the frequency band switching and data separation are realized through a hardware circuit. The physical isolation transmission of ranging data and auxiliary information is realized, which not only improves the ranging accuracy in NLOS and multipath scenarios by using the multipath suppression capability of main frequency CSS and chirp code, but also guarantees the uninterrupted transmission of key data through the strong penetration of low frequency, double-adapts to the needs of complex rescue environment, reduces data conflicts, and improves the transmission accuracy of ranging data and the transmission stability of auxiliary information.

[0029] Considering that the main frequency mode transmits ranging data, but does not solve the problems of random error and one-way error of ranging data, such as multi-round measurement fluctuation and single initiator crystal oscillator deviation, which leads to insufficient ranging accuracy, in order to solve this problem, in one possible implementation, in step 1, when the main frequency mode transmits ranging data, the main base station and the slave base station perform multiple independent measurements on the same distance and take the average, and the main base station and the slave base station and the mobile target respectively initiate the ranging process and perform cross verification, and the ranging data transmission is completed through bidirectional data interaction.

[0030] It should be noted that multiple independent measurements refer to repeated measurements of the same distance between base stations to reduce random error. Cross verification refers to the base station and the mobile target respectively initiating the ranging process, comparing the consistency of the two results to ensure data reliability. The multipath effect in NLOS scenarios will cause the superposition distortion of direct signal and multipath signal in single ranging, and although the correlation operation of CSS+chirp code can separate part of the multipath, there may still be a small amount of error. Multiple measurements take the average to further smooth the random error caused by multipath, and cross verification can avoid the deceptive error caused by multipath interference in one-way measurement.

[0031] In a specific implementation process, when the main base station and the slave base station transmit ranging data through the main frequency mode, the same distance is measured 5 times in succession, the maximum value and the minimum value are removed, and the average value is taken as the effective data; when the main base station and the mobile target measure the distance, the main base station initiates the ranging first, calculates the distance D1, then the mobile target initiates the ranging, calculates the distance D2, if |D1-D2|≤0.3 meters, the error threshold is tightened to adapt to the rescue scene, then the average value is taken as the effective data, otherwise the ranging is re-measured.

[0032] This embodiment can reduce the random error and one-way error of ranging data, improve the distance measurement accuracy in rescue scenarios, and ensure the reliability of positioning coordinates.

[0033] Low frequency mode transmission auxiliary information, but not considering the time validity and emergency information priority problem of auxiliary information, in order to solve this problem, in a possible implementation, the step 1, the mobile target auxiliary information includes real-time attitude information and distress signal; Real-time attitude information is based on the timestamp of the main base station main frequency ranging data packet for periodic clock synchronization, and the sending time sequence is calibrated once for each received main frequency ranging data; After the distress signal is triggered, the transmission of non-emergency information is suspended until the distress signal is sent.

[0034] For example, the mobile target auxiliary information includes real-time attitude information, such as the direction of movement of the rescue personnel, whether to fall and the distress signal, such as the distress signal triggered by the emergency button. Clock synchronization refers to the mobile target based on the timestamp of the main base station to calibrate its own clock, to ensure that the data sending time sequence is consistent. Non-emergency information refers to ordinary data other than distress signal, such as regular attitude information. The attitude information of the mobile target needs to be associated with time to be effective, and clock synchronization ensures that the time reference is consistent; The priority of the distress signal is the highest, and it needs to be transmitted preferentially to ensure the safety of the rescue personnel.

[0035] In the specific implementation process, the real-time attitude information of the mobile target is collected by a three-axis acceleration sensor, and data is generated once every 50ms. High-frequency collection is suitable for fast-moving scenarios. Based on the timestamp of the main base station main frequency ranging data packet, the clock is calibrated to nanoseconds to ensure that the sending time sequence is synchronized with the main base station; When the distress signal is triggered, such as the rescue personnel pressing the emergency button, the mobile target suspends the transmission of non-emergency information, and preferentially transmits the distress signal 5 times through the low frequency channel, including its own identification and timestamp, until it receives the confirmation response of the main base station.

[0036] In a possible implementation, in step 1, the communication data frame of the main frequency mode includes frame header, synchronization word, frame application data and frame tail; The frame application data includes scrambling code, packet type, destination address, source address, data length, ranging identification and check field; The ranging identification is used to distinguish the first ranging from the retry ranging.

[0037] Step 2, after the main base station is started, the low frequency mode based on the dual-band communication architecture sends the start-up signal to the upper computer.

[0038] It should be noted that the main base station refers to the core base station responsible for overall management, parameter configuration and interaction with the upper computer in the system; The upper computer refers to the command center equipment used for monitoring and controlling the entire positioning system; The start-up signal refers to the status notification signal sent by the main base station to the upper computer after the start-up is completed, including the main base station identification and start-up time.

[0039] In the specific implementation process, after the main base station is powered on, hardware self-checking is completed, such as radio frequency module and antenna state detection. After the self-checking is passed, a low-frequency mode is activated, a start-up signal containing a unique identifier of the main base station, such as BS-M-001, and a start-up timestamp is generated, and is sent to the upper computer through a 433 MHz frequency band. The sending period is 1 s, and the start-up signal is sent until the upper computer is received. The upper computer is ensured to know the start-up state of the main base station in real time, a trigger condition is provided for a subsequent configuration process, and system initialization lag is avoided.

[0040] Step 3: After the upper computer receives the start-up signal, a configuration instruction containing running parameters is generated, and is sent to the main base station through the low-frequency mode.

[0041] Step 4: The main base station receives and analyzes the configuration instruction, generates synchronization information with a synchronization identifier after completing self-parameter configuration, and broadcasts the synchronization information to the slave base station through the low-frequency mode.

[0042] It should be noted that the configuration instruction refers to an instruction generated by the upper computer according to the rescue scene demand, and used for setting running parameters of the main base station. The running parameter refers to a core working parameter of the main base station, such as a main frequency ranging period, a low-frequency communication power and the like. The main base station needs to configure the running parameter according to the complexity of the rescue scene, and the running parameter is uniformly sent by the upper computer to ensure standardization and consistency of the parameter.

[0043] In the specific implementation process, after the upper computer receives the start-up signal, a configuration instruction is generated based on a preset rescue scene parameter template, and contains running parameters: a main frequency ranging period of 30 ms, a low-frequency transmission power of 12 dBm, and a region code RUIN-01. The instruction is encrypted through the low-frequency mode, is sent to the main base station after the AES algorithm is used, and a check result is returned after the main base station receives the instruction. If the check fails, the upper computer re-sends. The remote standardized configuration of the main base station parameter is realized, errors of manual on-site setting are reduced, and the system initialization efficiency is improved.

[0044] In a possible implementation, in step 4, the synchronization identifier is a unique sequence that is sequentially incremented, and is associated with version information of the configuration instruction; and the synchronization information contains the configuration instruction and the synchronization identifier.

[0045] It should be noted that the synchronization identifier refers to a sequence generated by the main base station, and used for uniquely marking a version of the synchronization information. The format is a version number + an incremental serial number, such as V2.1-005. The version number is associated with the version of the configuration instruction, and the incremental serial number is increased by 1 each time new synchronization information is generated. The configuration instruction version information refers to an identifier used for distinguishing iterations of the configuration instruction, such as V1.0V2.1. Different versions correspond to different combinations of running parameters. The synchronization information refers to a data frame broadcasted by the main base station to the slave base station, contains the configuration instruction, complete running parameters and the synchronization identifier, and is used for parameter configuration and version checking of the slave base station.

[0046] The configuration instruction in system operation can be updated due to scene changes, such as adjusting the ranging period, and the synchronization identifier is identified by associating version information and an incremental serial number, so as to ensure that only the latest configuration is received and executed from the base station, and to avoid parameter inconsistency caused by confusion between old and new instructions.

[0047] In the specific implementation process, the synchronization identifier generation refers to that the master base station generates a synchronization identifier V2.0-012 based on the version information of the configuration instruction, such as the current version V2.0 and the historical synchronization times, such as broadcasting for the 12th time, wherein V2.0 corresponds to the configuration instruction version, and 012 is a unique serial number that is sequentially incremented; The synchronization information composition refers to that the synchronization information adopts a structured data frame format, which includes a frame header, identifies the synchronization information type, the synchronization identifier V2.0-012, the configuration instruction, complete operation parameters: the main frequency period 20 ms, the region code CAVE-02, and a check code for data integrity verification and a frame tail. The broadcasting and checking refer to that the master base station broadcasts the synchronization information through a low-frequency mode, and the slave base station first parses the synchronization identifier after receiving the synchronization information. If the version number is higher than the configuration instruction version stored locally, or the serial number is larger, the check code is verified, and after passing, the configuration instruction is parsed and the local parameters are updated. If the version number or the serial number is lower than the local one, the synchronization information is directly discarded.

[0048] Step 5, the slave base station receives the synchronization information, parses the synchronization identifier and the configuration instruction therein, completes the parameter configuration of itself, returns the confirmation information to the master base station, and relays and forwards the synchronization information until all the slave base stations in the system complete the configuration, forming an initialized base station network.

[0049] It should be noted that the slave base station refers to a base station in the system that is managed by the master base station and assists the master base station to complete ranging and data forwarding; the confirmation information refers to the state feedback sent by the slave base station to the master base station after completing the configuration, including the slave base station identifier and the configuration completion identifier; the relay forwarding refers to the operation of the slave base station forwarding the received synchronization information to other slave base stations in the uncovered area.

[0050] In the rescue scene, the slave base stations are distributed relatively dispersedly, such as in each area of the ruins, and the master base station broadcasting may exist a coverage blind area, and the relay forwarding can ensure that all the slave base stations receive the synchronization information; the master base station counts the configuration completion condition through the confirmation information, and judges whether the network is ready.

[0051] In a possible implementation, in step 5, when the slave base station relays and forwards the synchronization information, the synchronization identifier is kept unchanged; the confirmation information returned by the slave base station to the master base station includes the identifier of itself and the configuration completion identifier; when the master base station accumulates the number of received confirmation information and the total number of slave base stations preset by the system are consistent, it is determined that the base station network initialization is completed.

[0052] In the specific implementation process, after receiving the synchronization information from the base station, the synchronization identifier and the configuration instruction are parsed. If the synchronization identifier is the latest version, the parameter configuration is completed according to the instruction, such as setting the area code and the communication period. After the configuration is completed, the confirmation information is generated, which contains the base station identifier BS-S-001 and the configuration completion identifier OK, and is sent to the main base station through the low-frequency mode. If the slave base station detects that there is an unconfigured slave base station around, the synchronization information is relayed as it is, and the synchronization identifier is kept unchanged. When the number of received confirmation information of the main base station is consistent with the preset total number of slave base stations, it is determined that the base station network initialization is completed.

[0053] Step 6, after the mobile target is started, the main base station signal in the initialized base station network is searched through the low-frequency mode, and the registration request containing the identifier of the mobile target is sent.

[0054] It should be noted that the mobile target refers to the positioning tag carried by the movable object. The registration request refers to the access application signal sent by the mobile target to the main base station, which contains the identifier of the mobile target. The identifier of the mobile target refers to the unique identity of the mobile target, which is prefixed by the preset character of the mobile target, such as T-, and contains the same area code and the unique serial number of the mobile target as the main base station, such as T-RUIN-01-001. The mobile target needs to join the initialized base station network to realize positioning, and the registration request is used to verify its legality and establish communication association.

[0055] In the specific implementation process, after the mobile target is started, the low-frequency mode is activated to search for the main base station signal. By identifying the main base station identifier in the 433MHz frequency band, when the main base station signal in the initialized base station network is searched, the registration request containing the identifier T-RUIN-01-001 of the mobile target is generated and sent to the main base station through the low-frequency mode. The sending period is 300ms, and the high-frequency sending is suitable for the real-time demand of the rescue scene. Until the registration response is received.

[0056] In one possible implementation, in step 6, the identifier of the mobile target is prefixed by the preset character of the mobile target, and contains the same area code and the unique serial number of the mobile target as the main base station; in step 7, the identifier of the main base station is prefixed by the preset character of the base station, and contains the area code and the unique serial number of the base station, wherein the preset character of the mobile target and the preset character of the base station are different characters, and the unique serial number of the mobile target and the unique serial number of the base station belong to independent numbering sequences.

[0057] It should be noted that the mobile target preset character refers to the prefix character uniformly allocated by the system for the mobile target, such as a rescue worker label and a search and rescue robot, such as T-, which is used to quickly distinguish the device type; the base station preset character refers to the prefix character uniformly allocated by the system for the base station, such as a master base station and a slave base station, such as BS-, which is clearly distinguished from the mobile target preset character; the area code refers to a string identifying the physical area to which the device belongs, such as RUIN-01 representing a ruin rescue No. 1 area, and the master base station shares the same area code with the mobile target in the area; the mobile target unique serial number refers to an independent number allocated for the mobile target in the same area, such as 001 and 002, which ensures that each mobile target identification is unique; and the base station unique serial number refers to an independent number allocated for the base station in the same area, such as M-001 and S-001, wherein M represents the master base station, and S represents the slave base station, which belongs to a different sequence from the mobile target serial number.

[0058] In the indoor rescue scene, there are various types of devices, such as base stations, rescue worker labels, robots, etc., and a unified and differentiated identification structure can avoid identity confusion, the area code ensures clear device ownership, and the independent serial number guarantees globally unique identification, which facilitates the system to quickly identify and manage the device.

[0059] In the specific implementation process, the mobile target itself identification format is: mobile target preset character + area code + mobile target unique serial number. For example, T-RUIN-01-001, T- is the mobile target preset character, RUIN-01 is the area code, and 001 is the unique serial number of the mobile target in the area.

[0060] The master base station itself identification format is: base station preset character + master base station identification, M + area code + base station unique serial number. For example, BS-M-RUIN-01-001, BS- is the base station preset character, M represents the master base station, RUIN-01 is the area code, and 001 is the unique serial number of the base station in the area.

[0061] The system presets the mobile target preset character and the base station preset character, which cannot be repeated, such as T- and BS-, the mobile target serial number starts from 001 and increments, the base station serial number starts from M-001, the master base station, and S-001, the slave base station, and the two types of serial numbers are independently counted.

[0062] Step 7, after receiving the registration request, the master base station returns a registration response containing the master base station identification.

[0063] It should be noted that the registration response refers to the reply signal of the mobile target registration request by the main base station, and contains the main base station identifier; the main base station identifier refers to the unique identity of the main base station, and is prefixed by a base station preset character, such as BS-M-, and contains the area code and the unique serial number of the base station, such as BS-M-RUIN-01-001. The mobile target needs to know the main base station identifier to establish the subsequent communication link, and the registration response is used to confirm the successful registration and provide the main base station identity information.

[0064] In the specific implementation process, after the main base station receives the registration request, the area code of the mobile target is verified, which needs to be consistent with the area code of the main base station. After the verification is passed, the registration response is generated, which contains the main base station identifier BS-M-RUIN-01-001, and is sent to the mobile target through the low frequency mode. The identity binding of the mobile target and the main base station is completed, which provides a basis for subsequent communication link establishment and ensures the accurate association of real-time positioning data of rescue personnel.

[0065] Step 8, the mobile target receives the registration response, stores the main base station identifier, establishes the communication link with the main base station and the slave base station based on the dual-band communication architecture, and completes the system initialization.

[0066] In one possible implementation, in step 8, the communication link established by the mobile target with the main base station and the slave base station includes a main frequency channel and a low frequency channel, wherein the main frequency channel is used for transmitting ranging data, and the low frequency channel is used for transmitting mobile target auxiliary information; the mobile target periodically sends a link detection frame through the low frequency channel, and the main base station and the slave base station return a response frame after receiving the link detection frame.

[0067] It should be noted that the communication link refers to the bidirectional data transmission channel between the mobile target and the main base station and the slave base station, and includes a main frequency channel and a low frequency channel. The main frequency channel refers to the channel based on the main frequency mode in the communication link, which is used for transmitting ranging data; the low frequency channel refers to the channel based on the low frequency mode in the communication link, which is used for transmitting mobile target auxiliary information. The link detection frame refers to the signal frame periodically sent by the mobile target to verify whether the communication link is smooth. The final goal of system initialization is to establish stable communication between the mobile target and the base station, to ensure independent transmission of ranging data and auxiliary information through the frequency division channel, and the link detection frame is used to monitor the link state in real time.

[0068] In the specific implementation process, after receiving the registration response, the mobile target stores the main base station identifier BS-M-RUIN-01-001, and establishes a communication link based on a dual-band communication architecture: a main frequency channel, 2.4 GHz, is used to send ranging data to the main base station and the slave base station; a low frequency channel, 433 MHz, is used to send mobile target auxiliary information. The mobile target sends a link detection frame every 1s through the low frequency channel, which contains its own identifier. After receiving the response frame, the main base station and the slave base station return a response frame. If no response is received for 2 consecutive times, the mobile target reinitiates link establishment and shortens the detection period to adapt to the high reliability requirement of the rescue scene. After completing the link establishment, the system initialization is completed. Full-duplex communication between the mobile target and the base station is realized, and the high-frequency link detection mechanism ensures the stability of the communication in the complex rescue environment, and the system initialization closed loop is completed.

[0069] In summary, in the system initialization process, the main base station as the core node completes the interaction with the upper computer and parameter configuration, realizes the batch parameter synchronization and version management of the slave base station through the generation of a unique synchronization identifier, and the slave base station expands the coverage range of the synchronization information through relay forwarding, and completes the initialization judgment of the base station network in combination with the counting statistics of the confirmation information, and builds a stable base station communication network; the mobile target completes registration access through the low frequency mode, realizes identity binding and rapid identification with the base station relying on the differentiated identifier structure, and finally establishes communication links with the main base station and the slave base station based on the dual-band architecture, forms a complete initialization closed loop from the slave base station network construction to the mobile target access, and simultaneously monitors the communication state in real time through the link detection mechanism to ensure the stability and reliability of the link.

[0070] In addition, the present application is based on the problem of non-line-of-sight obstruction and multipath effect interference which exists universally in indoor rescue scenes, and differentiates the use of the technical characteristics of the main frequency mode and the low frequency mode with the dual-band communication architecture as the core carrier. The main frequency mode relies on the modulation and demodulation capability of the CSS technology and chirp code to realize effective separation and suppression of multipath signals, accurately calculates the distance by extracting the signal propagation time, and further reduces the random error and one-way error of the ranging data through the mechanism of multiple independent measurements and bidirectional cross verification, thereby providing bottom technical support for positioning accuracy. The low frequency mode has strong penetration and anti-interference, undertakes the transmission tasks of configuration parameters, control instructions and mobile target auxiliary information, guarantees the time effectiveness of attitude information through clock synchronization, ensures the timely transmission of the distress signal through priority allocation, and solves the problem of interruption of key information transmission in the non-line-of-sight scene.

[0071] The present application aims at the problems of insufficient ranging accuracy, incomplete communication coverage, chaotic device management, and lagging emergency information transmission in indoor positioning in rescue scenarios, discards the limitations of single frequency band and traditional ranging method, adopts a design idea of frequency band function separation, decouples high-precision ranging against multipath and auxiliary information transmission against obstruction, simultaneously integrates standardized parameter configuration process, differentiated device identification system, and hierarchical interference processing mechanism, realizes precise matching of technical characteristics and scene requirements, forms a set of indoor positioning data interaction and initialization scheme suitable for non-line-of-sight and complex environment with multipath effect, which not only guarantees the high accuracy of positioning data, but also ensures the stability of communication process and the timeliness of information transmission.

[0072] In a possible implementation, in step 8, after the mobile target establishes a communication link with the master base station and the slave base station, the mobile target transmits ranging data to the master base station through the master frequency mode, and synchronously adds a data confidence identifier. The identifier is based on a signal strength register built-in the tag, and the output value determines that the confidence identifier is low when the signal strength is lower than a preset threshold, and otherwise is high. After the master base station receives the ranging data, for ranging data with low confidence identifier for three or more times in succession, the master base station starts a sliding window filtering process, and replaces the abnormal value with the mean value of the first five valid ranging data in the window. If the deviation of single ranging data from the previous three normal ranging data exceeds a preset proportion, and the confidence identifier of the data is low, the master base station determines that it is transient interference data and discards it, and fills in the ranging value at this moment based on the historical trajectory trend prediction. After the confidence identifier of the mobile target for three times in succession is high, and the preset normal transmission condition is met, the master base station stops the prediction filling and restores the real-time ranging data.

[0073] It should be noted that the data confidence identifier refers to the quality mark added by the mobile target to the ranging data, which is high or low, and is determined based on the output value of the signal strength register. The sliding window filtering refers to a processing method of replacing the current data with the mean value of the historical valid data in a fixed length window for continuous abnormal data. The transient interference data refers to data with large deviation from the historical normal data and low confidence. The preset normal transmission condition refers to the confidence identifier of the mobile target for three times in succession being high, indicating that the signal is stable.

[0074] The mobile target is easily obstructed or interfered by electromagnetic waves in complex rescue environments such as ruins and smoke, resulting in transient abnormal ranging data. The confidence identifier can distinguish the data quality and process the abnormal data.

[0075] In the specific implementation process, when the mobile target transmits ranging data through the main frequency mode, the signal strength register detects the received signal strength RSSI in real time. If RSSI is greater than or equal to -90 dBm, the confidence level is high; otherwise, the confidence level is low. After the main base station receives the ranging data, if the confidence level is low for three or more times in succession, the sliding window filtering is started, and the window size is the previous five valid data. The current data is replaced by the mean value. If the deviation between the single data and the previous three normal data exceeds 20% and the confidence level is low, the data is determined to be instantaneous interference data and is discarded. The trajectory trend prediction is based on the previous 10 data to fill in the value at this time. When the confidence level of the mobile target is high for three times in succession, the main base station stops the prediction and restores the real-time ranging data.

[0076] The embodiment can effectively filter abnormal data caused by instantaneous interference, reduce the ghost displacement of the positioning trajectory of the rescue personnel, and improve the accuracy of the position judgment of the rescue personnel by the command center.

[0077] In a possible implementation, if the deviation between the real-time ranging data received by the main base station and the historical normal trajectory continuously exceeds a preset range, the main base station sends a signal distortion collection instruction to the mobile target through a low frequency mode; The mobile target collects distortion parameters of the current main frequency signal based on the signal distortion collection instruction, including signal phase offset and spectral purity, and returns the distortion parameters to the main base station in the feedback frame of the low frequency mode; The main base station extracts the distortion parameters in the feedback frame, matches them with a preset environmental interference feature library, and determines that there is systematic interference if the matching is successful and the duration reaches a preset threshold. The main base station calls a pre-stored calibration coefficient corresponding to the systematic interference to perform secondary correction on the ranging data after the sliding window filtering or the instantaneous interference data discarding processing; After the secondary correction, the main base station coordinates at least three different slave stations to perform synchronous ranging on the same mobile target, calculates the variance of the ranging data returned by each slave station, and uses the mean value corresponding to the variance as the valid ranging data if the variance is less than a preset threshold. If the variance exceeds the preset threshold, the main base station suspends the positioning output of the mobile target. When the distortion parameters fed back by the mobile target fail to match the interference feature library, the main base station stops the secondary correction and restores the processing based on the real-time ranging data.

[0078] It should be noted that the systematic interference refers to the overall shift of the ranging data caused by the continuous electromagnetic environment influence, such as the reflection of metal structures in the ruins and the electromagnetic radiation of rescue equipment; the distortion parameter refers to the characteristic change of the main frequency signal after being interfered, such as the phase shift and the spectral purity; the environment interference feature library refers to the preset known interference source, such as the distortion parameter template corresponding to the metal reflection and the electromagnetic radiation of the generator; the calibration coefficient refers to the ranging data correction value for a specific systematic interference, such as the fixed offset; and the multi-base station cross verification refers to the synchronous ranging of multiple slave base stations, and the consistency of the comparison results is compared to verify the correction effect.

[0079] The systematic interference can cause the overall shift of the ranging data, rather than the instantaneous jump, and the confidence identifier can be high, so the type of interference needs to be identified by matching the distortion parameter and corrected accordingly.

[0080] In the specific implementation process, when the mobile target meets the preset normal transmission condition, i.e., the confidence is high for three times in succession, but the real-time ranging data received by the master base station deviates from the historical trajectory by more than 1 meter, the master base station starts the systematic interference detection: the master base station sends a signal distortion collection instruction to the mobile target through a low-frequency mode; the mobile target collects the phase shift and spectral purity of the current main frequency signal and returns them in the low-frequency feedback frame; the master base station matches the distortion parameters with the environment interference feature library, and if the matching is successful for more than 5s, it is determined that there is systematic interference; the master base station calls the pre-stored calibration coefficient to perform secondary correction on the processed ranging data; at least three slave base stations are coordinated to perform synchronous ranging, and the variance of the corrected data is calculated: if the variance is less than or equal to 0.3m, the mean value is taken as the effective data; otherwise, the positioning output is suspended; when the distortion parameters fed back by the mobile target fail to match the feature library, the master base station stops the secondary correction and resumes the processing based on the real-time ranging data.

[0081] The embodiment can quickly identify and correct the ranging deviation caused by systematic interference, ensure the validity of the correction through multi-base station verification, improve the positioning accuracy in complex rescue environment, and provide a reliable basis for rescue decision-making.

[0082] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A data interaction and initialization method for an indoor positioning system, characterized in that, Includes the following steps: Step 1: Construct a dual-band communication architecture, which includes a main frequency mode and a low frequency mode. The main frequency mode is used to transmit ranging data between the main base station and the slave base station, and ranging data between the main base station, the slave base station and the moving target. The low frequency mode is used to transmit configuration parameters, control commands and moving target auxiliary information. Step 2: After the main base station is started, it sends a power-on signal to the host computer based on the low-frequency mode of the dual-band communication architecture. Step 3: After receiving the power-on signal, the host computer generates a configuration command containing operating parameters and sends it to the main base station in low-frequency mode. Step 4: The master base station receives and parses the configuration command, completes its own parameter configuration, generates synchronization information with a synchronization identifier, and broadcasts it to the slave base stations in low-frequency mode. Step 5: Receive the synchronization information from the base station, parse the synchronization identifier and configuration instructions, complete the configuration of its own parameters, return confirmation information to the main base station, and relay the synchronization information until all slave base stations in the system have completed the configuration, forming a base station network that has been initialized. Step 6: After the mobile target is started, it searches for the main base station signal in the initialized base station network in low frequency mode and sends a registration request containing its own identifier. Step 7: After receiving the registration request, the main base station returns a registration response containing the main base station identifier; Step 8: The mobile target receives the registration response, stores the master base station identifier, establishes communication links with the master base station and slave base stations based on the dual-band communication architecture, and completes system initialization.

2. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 1, when transmitting ranging data in master frequency mode, the master base station and the slave base station perform multiple rounds of independent measurement on the same distance and take the average value. The master base station, the slave base station and the moving target initiate the ranging process and perform cross-verification respectively, and the ranging data transmission is completed through bidirectional data interaction.

3. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 4, the synchronization identifier is a unique sequence that increments sequentially and is associated with the version information of the configuration instruction; the synchronization information includes the configuration instruction and the synchronization identifier.

4. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 5, when the base station relays the synchronization information, the synchronization identifier remains unchanged; the confirmation information returned by the base station to the master base station includes its own identifier and the configuration completion identifier; when the number of confirmation information received by the master base station is consistent with the total number of base stations preset by the system, the base station network initialization is determined to be complete.

5. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 6, the mobile target's self-identification begins with a preset character for the mobile target and includes the same area code and unique serial number as the main base station; in step 7, the main base station's self-identification begins with a preset character for the base station and includes an area code and unique serial number, wherein the preset character for the mobile target and the preset character for the base station are different characters, and the unique serial number for the mobile target and the unique serial number for the base station belong to independent numbering sequences.

6. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 8, the communication link established between the mobile target and the master base station and the slave base station includes a main frequency channel and a low frequency channel. The main frequency channel is used to transmit ranging data, and the low frequency channel is used to transmit mobile target auxiliary information. The mobile target periodically sends link detection frames through the low frequency channel, and the master base station and the slave base station receive them and return response frames.

7. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 1, the mobile target auxiliary information includes real-time attitude information and distress signal; the real-time attitude information is periodically clock-synchronized based on the timestamp of the main base station's main frequency ranging data packet, and the transmission timing is calibrated once every time the main frequency ranging data is received; after the distress signal is triggered, the transmission of non-emergency information is suspended until the distress signal is sent.

8. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 1, the communication data frame in the main frequency mode includes a frame header, a synchronization word, frame application data, and a frame tail; the frame application data includes a scrambling code, packet type, destination address, source address, data length, ranging identifier, and a check field; the ranging identifier is used to distinguish between the first ranging and the retry ranging.

9. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, In step 8, after the mobile target establishes a communication link with the main base station and the slave base station, when the mobile target transmits ranging data to the main base station in the main frequency mode, a data confidence indicator is added synchronously. This indicator is determined based on the output value of the signal strength register built into the tag: when the signal strength is lower than a preset threshold, the confidence indicator is low; otherwise, it is high. After receiving ranging data, the main base station initiates sliding window filtering for ranging data with three or more consecutive low confidence levels, replacing outliers with the average of the first five valid ranging data within the window. If the deviation between a single ranging data and the previous three normal ranging data exceeds a preset ratio, and the confidence level of the data is marked as low, the main base station determines it to be instantaneous interference data and discards it, and fills the ranging value at that moment based on historical trajectory trend prediction. If the confidence level of a moving target is marked as high for three consecutive times and the preset normal transmission conditions are met, the main base station stops predictive filling and resumes using real-time ranging data.

10. The data interaction and initialization method for an indoor positioning system according to claim 1, characterized in that, If the deviation between the real-time ranging data received by the main base station and the historical normal trajectory continues to exceed the preset range, the main base station sends a signal distortion acquisition command to the moving target in low-frequency mode. The moving target collects the distortion parameters of the current main frequency signal based on the signal distortion acquisition command, including the signal phase offset and spectral purity, and adds the distortion parameters to the low-frequency mode feedback frame and returns them to the main base station. The main base station extracts the distortion parameters in the feedback frame and matches them with the preset environmental interference feature library. If the match is successful and the duration reaches the preset threshold, it is determined that there is systematic interference. The main base station calls the pre-stored calibration coefficients corresponding to the systemic interference to perform secondary correction on the ranging data after sliding window filtering or instantaneous interference data discarding; After the second correction, the main base station coordinates at least three different slave base stations to synchronously measure the distance to the same moving target. The variance of the corrected ranging data returned by each slave base station is calculated. If the variance is less than a preset threshold, the mean value corresponding to the variance is used as the valid ranging data. If the variance exceeds a preset threshold, the main base station will suspend the positioning output of the moving target; When the distortion parameters fed back by the moving target fail to match the interference feature library, the main base station stops the secondary correction and resumes processing based on real-time ranging data.

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