Data interaction and initialization method of an indoor positioning system

Abstract

The application discloses a data interaction and initialization method of an indoor positioning system, and relates to the technical field of indoor positioning. The method constructs a dual-band communication architecture, a main frequency mode is used to transmit ranging data between base stations and between a base station and a mobile target, and a low frequency mode is used to transmit configuration parameters, control instructions and mobile target auxiliary information; after a main base station starts, a start signal is sent to an upper computer, after a configuration instruction is received from the upper computer, synchronization information with a synchronization identifier is generated and broadcast to a slave base station, the slave base station feeds back a confirmation after completing configuration and relays forwarding, and an initialization base station network is formed; a mobile target searches for a main base station signal through the low frequency mode and sends a registration request, after receiving a response containing a main base station identifier, a communication link with the main base station and the slave base station is established, and system initialization is completed. Through dual-band separate transmission and a standardized initialization process, the application reduces data interference, improves parameter synchronization efficiency and guarantees stable operation of the positioning system.

Description

Technical Field

[0001] This invention relates to the field of indoor positioning technology, and in particular to a data interaction and initialization method for an indoor positioning system. Background Technology

[0002] In existing technologies, indoor positioning systems often use a single frequency band for communication, synchronously transmitting various types of data, such as ranging data between base stations, equipment configuration parameters, and moving target auxiliary information. Because ranging data requires extremely high transmission accuracy, spread spectrum communication is often used. However, configuration parameters and auxiliary information have stringent real-time transmission requirements. When transmitted on a single frequency band, these two types of data are prone to mutual interference, leading to an increased error rate in ranging data transmission or increased delays in auxiliary information, thus affecting positioning accuracy and system response speed.

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

[0004] To address the technical problems existing in the prior art, this invention provides a data interaction and initialization method for an indoor positioning system.

[0005] The technical solution adopted in this invention is: a data interaction and initialization method for an indoor positioning system, comprising the following steps:

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] Step 7: After receiving the registration request, the main base station returns a registration response containing the main base station identifier;

[0013] 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.

[0014] Preferably, 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.

[0015] Preferably, 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.

[0016] Preferably, 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, it is determined that the base station network initialization is complete.

[0017] Preferably, 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.

[0018] Preferably, 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, wherein 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 and return response frames.

[0019] Preferably, 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 each 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.

[0020] Preferably, 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.

[0021] Preferably, 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] Preferably, if the deviation between the real-time ranging data received by the main base station and the historical normal trajectory continues to exceed a preset range, the main base station sends a signal distortion acquisition command to the moving target in low-frequency mode.

[0026] 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.

[0027] The main base station extracts the distortion parameters in the feedback frame and matches them with a preset environmental interference feature library. If the match is successful and the duration reaches a preset threshold, it is determined that there is systematic interference.

[0028] 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;

[0029] After the second correction, the master 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 distance measurement 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 distance measurement data. If the variance exceeds the preset threshold, the master base station suspends the positioning output of the moving target.

[0030] 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.

[0031] The beneficial effects of the present invention are at least one of the following: by constructing a dual-band communication architecture, ranging data between base stations and between base stations and mobile targets are transmitted in the main frequency mode, while configuration parameters, control commands and mobile target auxiliary information are transmitted in the low frequency mode. This achieves the separate transmission of different types of data, which helps to reduce mutual interference caused by mixed data transmission in a single frequency band, thereby improving the accuracy of ranging data transmission and the timeliness of auxiliary information transmission to a certain extent.

[0032] During system initialization, the standardized process of command interaction between the master base station and the host computer, broadcasting and relaying synchronization information from the master base station to the slave base station, confirmation feedback from the slave base station, and registration of the mobile target after the base station network initialization is completed helps to promote parameter synchronization among the master base station, slave base station and mobile target, reduce parameter inconsistencies, and shorten system startup time to a certain extent, thereby improving the stability of system initialization. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the method of the present invention. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] It should be noted that the present invention 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 moving target, and there are obstructions such as ruins, steel structures, thick smoke, and obstacles.

[0036] Multipath effect refers to the phenomenon where a signal travels from the transmitter to the receiver along multiple paths besides the direct path, such as those formed by reflections and scattering from obstacles like rubble walls, metal components, and dense smoke particles. This results in the receiver receiving both direct and multipath signals simultaneously, which, when superimposed, cause ranging errors. This is one of the factors affecting positioning accuracy in indoor rescue scenarios.

[0037] Considering that traditional indoor positioning systems use a single frequency band for transmission, leading to interference between ranging data and auxiliary information; the initialization process lacks standardized design, resulting in low efficiency and incomplete coverage in base station network construction; and there is no standardized process for mobile target access, leading to poor communication link stability and an inability to adapt to the positioning needs of complex scenarios such as indoor rescue, this embodiment provides a data interaction and initialization method for an indoor positioning system, such as... Figure 1 As shown, it includes the following steps:

[0038] 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.

[0039] It should be noted that a dual-band communication architecture refers to a system that simultaneously employs two different frequency band communication modes: a main frequency mode and a low-frequency mode, each carrying different types of data transmission.

[0040] The main frequency mode refers to the communication mode that uses a higher frequency band, such as 2.4GHz. It has the characteristics of fast transmission rate, high accuracy, wide spread spectrum bandwidth, and strong electromagnetic wave diffraction capability.

[0041] For example, the main frequency mode is implemented using CSS technology, which modulates and demodulates the ranging signal based on chirp codes. This effectively resists multipath effects and achieves high-precision ranging. Chirp codes are spreading codes whose frequency changes linearly with time. The time-frequency coupling characteristics of chirp codes allow the receiver to accurately extract the signal propagation time (ToF) through correlation operations. At the same time, it has good resolution of multipath reflected signals and can separate direct signals from delayed multipath signals. Therefore, it has the characteristics of high transmission rate, high ranging accuracy, strong electromagnetic wave diffraction capability, and outstanding multipath suppression capability, which can effectively reduce the ranging error caused by multipath effects.

[0042] Low-frequency mode refers to a communication mode that uses a lower frequency band, such as 433MHz, and has the characteristics of strong penetration and good anti-interference.

[0043] Inter-base station ranging data refers to the measurement data used to calculate the distance between the master base station and the slave base station; inter-base station ranging data refers to the measurement data used to calculate the distance between the master base station, the slave base station and the moving target, such as the positioning tag carried by rescuers or the signal transmitter of a trapped person.

[0044] Configuration parameters refer to parameters used to set the operating status of the base station and the mobile target, such as transmit power, communication cycle, chirp code type, CSS spread spectrum bandwidth, etc.; control commands refer to operation commands sent by the host computer or main base station to other devices, such as starting ranging, switching modes, etc. Mobile target auxiliary information refers to non-ranging data generated by the mobile target, such as the vital signs of rescuers, distress signals, etc.

[0045] In the specific implementation process, the system presets frequency band parameters for a main frequency mode and a low frequency mode. The main frequency mode uses the 2.4GHz band, configures CSS technical parameters, and sets the bandwidth to 80MHz. It generates ranging signals through chirp code modulation and is specifically used for transmitting ranging data between base stations and between a base station and a moving target. The low frequency mode uses the 433MHz band with a bandwidth of 250kHz, and is used to transmit configuration parameters, control commands, and auxiliary information for moving targets. The two modes work independently, with frequency band switching and data separation achieved through hardware circuitry. This achieves physical isolation transmission of ranging data and auxiliary information, utilizing the multipath suppression capabilities of the main frequency CSS and chirp codes to improve ranging accuracy in NLOS and multipath scenarios, while ensuring uninterrupted critical data transmission through the strong penetration of the low frequency. This dual adaptation meets the needs of complex rescue environments, reduces data conflicts, and improves the transmission accuracy of ranging data and the transmission stability of auxiliary information.

[0046] Considering that the main frequency mode transmits ranging data, but does not solve the problems of random and one-way errors in the ranging data, such as fluctuations in multiple rounds of measurement and deviations of the crystal oscillator of a single initiator, resulting in insufficient ranging accuracy, in order to solve this problem, in one possible implementation, when transmitting ranging data in the main frequency mode, the main base station and the slave base station perform multiple rounds of independent measurement on the same distance and take the average value. The main 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.

[0047] It should be noted that multi-round independent measurement refers to repeated measurements of the same distance between base stations to reduce random errors. Cross-validation refers to the base station and the moving target initiating ranging procedures separately, comparing the consistency of the two results to ensure data reliability. In NLOS scenarios, multipath effects can cause distortion due to the superposition of direct and multipath signals in a single ranging measurement. Although correlation operations using CSS+chirp codes can separate some multipath signals, a small amount of error may still remain. Averaging multiple measurements can further smooth out the random errors caused by multipath, and cross-validation can avoid deceptive errors caused by multipath interference in unidirectional measurements.

[0048] In the 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 consecutively, and the average value is taken after removing the maximum and minimum values ​​as valid data. When measuring the distance between the main base station and the moving target, the main base station initiates the ranging first and calculates the distance D1, and then the moving target initiates the ranging and calculates the distance D2. If |D1-D2|≤0.3 meters, the error threshold is tightened to adapt to the rescue scenario, and the average value is taken as valid data; otherwise, the ranging is measured again.

[0049] This implementation method can reduce random and one-way errors in ranging data, improve the accuracy of distance measurement in rescue scenarios, and ensure reliable positioning coordinates.

[0050] The low-frequency mode transmits auxiliary information, but does not take into account the time validity of the auxiliary information and the priority of emergency information. To solve this problem, in one possible implementation, the mobile target auxiliary information in step 1 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.

[0051] For example, mobile target auxiliary information includes real-time attitude information, such as the direction of movement of rescuers, whether they have fallen, and distress signals, such as a distress call triggered by an emergency button. Clock synchronization refers to the mobile target calibrating its own clock based on the timestamp of the main base station to ensure consistent data transmission timing. Non-emergency information refers to ordinary data other than distress signals, such as routine attitude information. The attitude information of the mobile target is only valid if it is correlated with time; clock synchronization ensures a consistent time base. Distress signals have the highest priority and must be transmitted first to ensure the safety of rescuers.

[0052] In the specific implementation process, the real-time attitude information of the moving target is collected by a three-axis accelerometer, generating data once every 50ms. The high-frequency acquisition is adapted to fast-moving scenarios. Based on the timestamp of the main base station's main frequency ranging data packet, the target's own clock is calibrated to nanosecond accuracy to ensure that the transmission sequence is synchronized with the main base station. When a distress signal is triggered, such as when rescuers press the emergency button, the moving target suspends the transmission of non-emergency information and prioritizes sending five distress signals through the low-frequency channel, including its own identifier and timestamp, until it receives a confirmation response from the main base station.

[0053] In one possible implementation, 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 trailer; 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.

[0054] 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.

[0055] It should be noted that the main base station refers to the core base station in the system that is responsible for overall management, parameter configuration, and interaction with the host computer; the host computer refers to the command center equipment used to monitor and control the entire positioning system; the power-on signal refers to the status notification signal sent by the main base station to the host computer after it has started up, which includes the main base station identifier and the start time.

[0056] In the specific implementation process, after the main base station is powered on, it completes hardware self-tests, such as RF module and antenna status detection. After the self-test passes, it activates low-frequency mode and generates a power-on signal containing the main base station's unique identifier, such as BS-M-001, and a startup timestamp. This signal is sent to the host computer via the 433MHz band with a transmission cycle of 1 second until confirmation is received from the host computer. This ensures that the host computer is aware of the main base station's startup status in real time, providing triggering conditions for subsequent configuration processes and avoiding system initialization delays.

[0057] 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.

[0058] 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.

[0059] It should be noted that configuration commands refer to instructions generated by the host computer based on the needs of the rescue scenario, used to set the operating parameters of the main base station. Operating parameters refer to the core working parameters of the main base station, such as the main frequency ranging period and low-frequency communication power. The main base station needs to configure operating parameters according to the complexity of the rescue scenario; unified distribution of these parameters by the host computer ensures standardization and consistency.

[0060] In the specific implementation process, after receiving the power-on signal, the host computer generates configuration instructions based on a preset rescue scenario parameter template, including operating parameters: main frequency ranging period 30ms, low frequency transmission power 12dBm, and area code RUIN-01. The instructions are encrypted in low frequency mode and sent to the main base station using the AES algorithm. After receiving the instructions, the main base station returns a verification result. If the verification fails, the host computer retransmits the instructions. This achieves remote standardized configuration of the main base station parameters, reduces errors from manual on-site settings, and improves system initialization efficiency.

[0061] In one possible implementation, 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.

[0062] It should be noted that: Synchronization identifiers are sequences generated by the master base station to uniquely identify the version of synchronization information. They use a version number + incrementing sequence number format, such as V2.1-005. The version number is associated with the version of the configuration instruction, and the incrementing sequence number increases by 1 with each new synchronization information generation. Configuration instruction version information is an identifier used to distinguish configuration instruction iterations, such as V1.0 and V2.1. Different versions correspond to different combinations of operating parameters. Synchronization information refers to the data frames broadcast by the master base station to the slave base station, containing configuration instructions, complete operating parameters, and synchronization identifiers, used for parameter configuration and version verification by the slave base station.

[0063] Configuration commands may be updated due to changes in the scenario during system operation, such as adjusting the ranging period. Synchronization identifiers are linked to version information and incrementing sequence numbers to ensure that only the latest configuration is received and executed from the base station, avoiding parameter inconsistencies caused by confusion between old and new commands.

[0064] In the specific implementation process, the synchronization identifier generation refers to the main base station generating 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 count, such as the 12th broadcast. V2.0 corresponds to the configuration instruction version, and 012 is a unique serial number that is incremented sequentially.

[0065] Synchronization information consists of a structured data frame format, including a frame header, a synchronization information type identifier, a synchronization identifier, V2.0-012, configuration instructions, complete operating parameters (main frequency period 20ms, area code CAVE-02, etc.), and a checksum used for data integrity verification and frame tail.

[0066] Broadcast and verification refers to the main base station broadcasting synchronization information in low-frequency mode. After receiving the information from the base station, the synchronization identifier is first parsed. If the version number is higher than the locally stored configuration instruction version, or the sequence number is larger, the verification code is verified. If the verification is successful, the configuration instruction is parsed and the local parameters are updated. If the version number or sequence number is lower than the local version, the synchronization information is discarded directly.

[0067] 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.

[0068] It should be noted that a 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 in completing ranging and data forwarding; confirmation information refers to the status feedback sent by the slave base station to the master base station after completing the configuration, which includes the slave base station identifier and the configuration completion identifier; 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.

[0069] In rescue scenarios, base stations are often scattered, such as in different areas of the ruins. The main base station's broadcast may have coverage blind spots. Relay forwarding can ensure that all slave base stations receive synchronized information. The main base station confirms the information to count the configuration completion status and determine whether the network is ready.

[0070] In one possible implementation, 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, it is determined that the base station network initialization is complete.

[0071] In the specific implementation process, after receiving synchronization information from the base station, the synchronization identifier and configuration instructions are parsed. If the synchronization identifier is the latest version, the parameter configuration is completed according to the instructions, such as setting the area code and communication cycle. After configuration, an acknowledgment message is generated, including the base station identifier BS-S-001 and the configuration completion identifier OK, and sent to the master base station in low-frequency mode. If the base station detects an unconfigured base station in the vicinity, it forwards the synchronization information as is, keeping the synchronization identifier unchanged. When the number of acknowledgment messages received by the master base station matches the preset total number of base stations, the base station network initialization is considered complete.

[0072] 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.

[0073] It should be noted that a mobile target refers to a location tag carried by a movable object. A registration request is an access application signal sent by the mobile target to the main base station, containing its own identifier. This identifier is the mobile target's unique identity, starting with a pre-defined string (e.g., T-) and including the same area code as the main base station and a unique serial number, such as T-RUIN-01-001. A mobile target needs to join an initialized base station network to achieve location tracking; the registration request is used to verify its legitimacy and establish a communication association.

[0074] In the specific implementation process, after the mobile target is activated, it activates the low-frequency mode to search for the main base station signal. By identifying the main base station identifier in the 433MHz band, when the main base station signal in the initialized base station network is found, a registration request is generated, which includes its own identifier T-RUIN-01-001. This request is sent to the main base station in low-frequency mode with a sending period of 300ms. The high-frequency sending adapts to the real-time requirements of the rescue scenario until a registration response is received.

[0075] In one possible implementation, 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.

[0076] It should be noted that the preset characters for mobile targets refer to the prefix characters uniformly assigned by the system to mobile targets, such as rescuer tags and search and rescue robots, such as T-, used to quickly distinguish the device type; the preset characters for base stations refer to the prefix characters uniformly assigned by the system to base stations, such as BS-, which are clearly distinguished from the preset characters for mobile targets; the area code refers to the string that identifies the physical area to which the device belongs, such as RUIN-01 representing the No. 1 area for rubble rescue, where the main base station and mobile targets in this area share the same area code; the unique serial number of a mobile target refers to the independent number assigned to a mobile target within the same area, such as 001, 002, ensuring that each mobile target is uniquely identified; the unique serial number of a base station refers to the independent number assigned to a base station within the same area, such as M-001, S-001, where M represents the main base station and S represents the slave base station, belonging to a different sequence from the serial number of the mobile target.

[0077] In indoor rescue scenarios, there are various types of equipment, such as base stations, rescuer tags, and robots. A unified and differentiated identification structure can avoid confusion of identities, regional coding ensures clear equipment ownership, and independent serial numbers ensure that the identification is globally unique, making it easy for the system to quickly identify and manage equipment.

[0078] In the specific implementation process, the format of the moving target's own identification is: moving target preset character + area code + moving target unique serial number. For example, in T-RUIN-01-001, T- is the moving target preset character, RUIN-01 is the area code, and 001 is the moving target unique serial number within that area.

[0079] The primary base station's self-identification format is: base station preset character + primary base station identifier, M + area code + unique base station serial number. For example, in BS-M-RUIN-01-001, BS- is the base station preset character, M represents the primary base station, RUIN-01 is the area code, and 001 is the unique serial number of the base station within that area.

[0080] The system presets that the mobile target preset characters and the base station preset characters cannot be repeated, such as T- and BS-. The mobile target sequence number starts from 001 and increments, while the base station sequence number starts from M-001, the main base station, and S-001, and increments from the base station. The two types of sequence numbers are counted independently.

[0081] Step 7: After receiving the registration request, the main base station returns a registration response containing the main base station identifier.

[0082] It should be noted that the registration response is the primary base station's reply signal to the mobile target's registration request, and includes the primary base station identifier. The primary base station identifier is the unique identifier of the primary base station, starting with a pre-defined character set, such as BS-M-, and including the area code and the base station's unique serial number, such as BS-M-RUIN-01-001. The mobile target needs to know the primary base station identifier to establish a subsequent communication link. The registration response is used to confirm successful registration and provide the primary base station's identity information.

[0083] In the specific implementation process, after receiving the registration request, the main base station verifies the area code of the mobile target, which must match its own area code. Upon successful verification, a registration response is generated, containing the main base station identifier BS-M-RUIN-01-001, and sent to the mobile target via low-frequency mode. This completes the identity binding between the mobile target and the main base station, providing a foundation for establishing subsequent communication links and ensuring the accurate association of real-time location data for rescue personnel.

[0084] 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.

[0085] In one possible implementation, 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, wherein 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 and return response frames.

[0086] It should be noted that a communication link refers to a bidirectional data transmission channel between a mobile target and both the master and slave base stations, including a primary frequency channel and a low-frequency channel. The primary frequency channel is the channel in the communication link based on the primary frequency mode, used for transmitting ranging data; the low-frequency channel is the channel in the communication link based on the low-frequency mode, used for transmitting auxiliary information of the mobile target. A link detection frame is a signal frame periodically sent by the mobile target to verify the connectivity of the communication link. The ultimate goal of system initialization is to establish stable communication between the mobile target and the base station. Frequency-division channels ensure independent transmission of ranging data and auxiliary information, and link detection frames are used to monitor the link status in real time.

[0087] In the specific implementation process, after receiving the registration response, the mobile target stores the master base station identifier BS-M-RUIN-01-001 and establishes a communication link based on a dual-band communication architecture: a master frequency channel (2.4GHz) for sending ranging data to the master and slave base stations; and a low-frequency channel (433MHz) for sending mobile target auxiliary information. The mobile target sends a link detection frame every 1 second via the low-frequency channel, containing its own identifier. The master and slave base stations receive and return response frames. If no response is received twice consecutively, the mobile target re-initiates link establishment, shortening the detection cycle to meet the high reliability requirements of rescue scenarios. After link establishment is completed, system initialization ends. This achieves full-duplex communication between the mobile target and the base station, and the high-frequency link detection mechanism ensures communication stability in complex rescue environments, completing the system initialization closed loop.

[0088] In summary, during the system initialization process, the master base station, as the core node, completes the interaction and parameter configuration with the host computer. It generates a unique synchronization identifier to achieve batch parameter synchronization and version management for slave base stations. The slave base stations then extend the coverage of synchronization information through relay forwarding. Combined with the counting statistics of confirmation information, the initialization judgment of the base station network is completed, and a stable base station communication network is built. The mobile target completes the registration and access through low-frequency mode. Relying on the differentiated identifier structure, it achieves identity binding and rapid identification with the base station. Finally, based on the dual-band architecture, a communication link is established with the master base station and slave base stations, forming a complete initialization closed loop from base station network construction to mobile target access. At the same time, the communication status is monitored in real time through the link detection mechanism to ensure the stability and reliability of the link.

[0089] In addition, this invention addresses the common problems of non-line-of-sight occlusion and multipath interference in indoor rescue scenarios. Using a dual-band communication architecture as its core, it differentiates the technical characteristics of the main frequency mode and the low-frequency mode. The main frequency mode, relying on CSS technology and chirp code modulation and demodulation capabilities, effectively separates and suppresses multipath signals. It accurately calculates distance by extracting signal propagation time, and further reduces random and unidirectional errors in ranging data by combining multiple rounds of independent measurement and bidirectional cross-verification, providing underlying technical support for positioning accuracy. The low-frequency mode, with its strong penetration and anti-interference capabilities, undertakes the transmission of configuration parameters, control commands, and moving target auxiliary information. It ensures the time validity of attitude information through clock synchronization and ensures timely transmission of distress signals through priority allocation, solving the problem of critical information transmission interruption in non-line-of-sight scenarios.

[0090] This invention addresses the pain points of indoor positioning in rescue scenarios, such as insufficient ranging accuracy, incomplete communication coverage, chaotic equipment management, and delayed emergency information transmission. It abandons the limitations of single frequency bands and traditional ranging methods, and adopts a frequency band function separation design concept to decouple high-precision ranging with multipath resistance from auxiliary information transmission with anti-obstruction capability. At the same time, it integrates standardized parameter configuration procedures, differentiated equipment identification systems, and layered interference handling mechanisms to achieve precise matching between technical characteristics and scenario requirements. This forms a set of indoor positioning data interaction and initialization schemes adapted to complex environments with non-line-of-sight and multipath effects, ensuring both high accuracy of positioning data and stability of communication processes and timeliness of information transmission.

[0091] In one possible implementation, 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 flag is added synchronously. The flag is determined based on the signal strength register built into the tag: when the signal strength is lower than a preset threshold, the confidence flag is low; otherwise, it is high.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] It should be noted that the data confidence indicator refers to the quality mark of the moving target attached to the ranging data, which is high or low, determined based on the output value of the signal strength register; sliding window filtering refers to the processing method of replacing the current data with the average of historical valid data within a fixed-length window for continuous abnormal data; instantaneous interference data refers to data in which the deviation of a single ranging data from historical normal data is too large and the confidence is low; preset normal transmission conditions refer to the fact that the confidence indicator of the moving target is high for three consecutive times, indicating that the signal is stable.

[0096] In complex rescue environments such as ruins and dense smoke, moving targets are easily obstructed or subject to electromagnetic interference, which can cause instantaneous anomalies in ranging data. Confidence level indicators can be used to distinguish data quality and address abnormal data in a targeted manner.

[0097] In the specific implementation process, when the moving target transmits ranging data through the main frequency mode, the signal strength register detects the received signal strength RSSI in real time. If RSSI ≥ -90dBm, the confidence level is marked as high; otherwise, it is marked as low. After the main base station receives the data: if the confidence level is low three or more times consecutively, a sliding window filter is activated, with the window size being the previous 5 valid data points, and the current data is replaced with the average value.

[0098] If a single data point deviates from the previous three normal data points by more than 20% and has a low confidence level, it is judged as transient interference data and discarded. The value at that moment is filled in based on the trajectory trend prediction of the previous 10 data points.

[0099] When the confidence level of a moving target is high three times consecutively, the main base station stops prediction and resumes using real-time ranging data.

[0100] This implementation method can effectively filter abnormal data caused by transient interference, reduce ghost displacement of rescue personnel's positioning trajectory, and improve the accuracy of the command center's judgment of rescue personnel's location.

[0101] In one possible implementation, if the deviation between the real-time ranging data received by the main base station and the historical normal trajectory continues to exceed a preset range, the main base station sends a signal distortion acquisition command to the moving target in low-frequency mode.

[0102] 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.

[0103] The main base station extracts the distortion parameters in the feedback frame and matches them with a preset environmental interference feature library. If the match is successful and the duration reaches a preset threshold, it is determined that there is systematic interference.

[0104] 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;

[0105] After the second correction, the master 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 distance measurement 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 distance measurement data. If the variance exceeds the preset threshold, the master base station suspends the positioning output of the moving target.

[0106] 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.

[0107] It should be noted that systematic interference refers to the overall offset of ranging data caused by the influence of a continuous electromagnetic environment, such as reflection from metal structures in ruins or electromagnetic radiation from rescue equipment; distortion parameters refer to the characteristic changes of the main frequency signal after interference, such as phase offset and spectral purity; the environmental interference feature library refers to the preset known interference sources, such as distortion parameter templates corresponding to metal reflection and generator electromagnetic radiation; calibration coefficients refer to the correction values ​​for ranging data for specific systematic interference, such as fixed offsets; and multi-base station cross-validation refers to verifying the correction effect by comparing the consistency of results through synchronous ranging from multiple base stations.

[0108] Systematic interference can cause an overall shift in ranging data rather than an instantaneous jump, and the confidence level may be high. It is necessary to identify the type of interference through distortion parameter matching and make targeted corrections.

[0109] In the specific implementation process, when the moving target meets the preset normal transmission conditions, i.e., three consecutive high confidence levels, but the deviation between the real-time ranging data received by the main base station and the historical trajectory continues to exceed 1 meter, the main base station initiates systemic interference detection: the main base station sends a signal distortion acquisition command to the moving target in low-frequency mode; the moving target acquires the phase offset and spectral purity of the current main frequency signal, appends it to the low-frequency feedback frame and returns it; the main base station matches the distortion parameters with the environmental interference feature library, and if the matching is successful for more than 5 seconds, it is determined to be systemic interference; the main base station calls the pre-stored calibration coefficients to perform secondary correction on the processed ranging data; it coordinates at least three slave base stations to synchronously measure the distance and calculates the variance of the corrected data: if the variance is ≤0.3m, the mean is taken as valid data; otherwise, the positioning output is paused; when the distortion parameters fed back by the moving target fail to match the feature library, the main base station stops the secondary correction and resumes processing based on the real-time ranging data.

[0110] This implementation method can quickly identify and correct ranging deviations caused by systematic interference, and ensure the effectiveness of the correction through multi-base station verification, thereby improving the positioning accuracy in complex rescue environments and providing a reliable basis for rescue decision-making.

[0111] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

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 a preset environmental interference feature library. If the match is successful and the duration reaches a 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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