Positioning data transmission method and system realized by talkback communication

Abstract

The invention discloses a positioning data transmission method and system realized by talkback communication, and relates to the technical field of high-precision positioning, and the method comprises the steps: obtaining a main positioning base station, an auxiliary positioning base station and a mobile talkback terminal, achieving the time synchronization, and setting a first positioning time point and a second positioning time point; obtaining first transmitting power, obtaining first receiving time and first receiving power, obtaining a first attenuation index, obtaining a first to-be-processed distance, obtaining a first correction index, and obtaining a first target distance; acquiring second transmitting power, second receiving time and second receiving power, acquiring a second attenuation index, acquiring a second to-be-processed distance, acquiring a second correction index, and acquiring a second target distance according to the second to-be-processed distance and the second correction index; and obtaining target positioning data of the mobile intercom terminal according to the first target distance and the second target distance. The method has the advantages of high communication positioning precision, multi-modal fusion distance measurement and dynamic data processing.

Description

Technical Field

[0001] The present invention relates to the technical field of high-precision positioning, and particularly relates to a positioning data transmission method and system implemented by intercom communication. Background Art

[0002] In the field of wireless positioning, existing technologies (such as GPS or Bluetooth beacons, etc.) often face challenges such as severe signal attenuation in indoor environments, multipath effect interference, high hardware costs, and insufficient dynamic target tracking accuracy. Especially in scenarios such as emergency communication, industrial inspection, and fire rescue, the following core problems exist in the existing technologies: First, the system redundancy caused by the separation of communication and positioning functions. In existing solutions, intercom devices are only used for voice or data transmission, and positioning relies on independent systems (such as GPS modules or dedicated positioning base stations), resulting in high device complexity and increased energy consumption; Second, the accuracy and robustness of a single ranging method are insufficient. Ranging based on received signal strength indication is easily affected by environmental attenuation, while time-delay ranging has extremely high requirements for clock synchronization accuracy, and the movement of dynamic targets will cause Doppler frequency shift interference. Existing technologies usually adopt a single ranging method, and the positioning error can reach dozens of meters in complex environments, making it difficult to meet the high-precision requirements; Finally, existing methods calculate the position through single measurement without considering the temporal continuity of the target, and the clock deviation of multi-base station collaborative positioning will introduce cumulative errors. At the same time, the current positioning data fusion algorithm adopts a fixed-weight data fusion strategy (such as weighted average).

[0003] In view of the above problems, there is an urgent need for a low-cost solution that integrates intercom communication and high-precision positioning, which can achieve precise positioning in complex environments while avoiding additional hardware deployment. Summary of the Invention

[0004] Aiming at the defects in the prior art, the present invention provides a positioning data transmission method and system implemented by intercom communication.

[0005] A positioning data transmission method implemented by intercom communication, comprising: obtaining a main positioning base station, an auxiliary positioning base station, and a mobile intercom terminal communicating with the base stations, realizing time synchronization of the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and setting a first positioning time point and a second positioning time point; obtaining the first transmission power of a first composite modulation signal sent by the mobile intercom terminal at the first positioning time point, obtaining the first reception time and the first reception power of the first composite modulation signal received by the main positioning base station, obtaining a first attenuation index according to the first transmission power and the first reception power, obtaining a first distance to be processed between the mobile intercom terminal and the main positioning base station according to the first attenuation index, obtaining a first correction index according to the first reception time and the first positioning time, and obtaining a first target distance according to the first distance to be processed and the first correction index; obtaining the second transmission power of a second composite modulation signal sent by the mobile intercom terminal at the second positioning time point, obtaining the second reception time and the second reception power of the second composite modulation signal received by the auxiliary positioning base station, obtaining a second attenuation index according to the second transmission power and the second reception power, obtaining a second distance to be processed between the mobile intercom terminal and the auxiliary positioning base station according to the second attenuation index, obtaining a second correction index according to the second reception time and the second positioning time, and obtaining a second target distance according to the second distance to be processed and the second correction index; obtaining the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance.

[0006] Optionally, realizing time synchronization of the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and setting a first positioning time point and a second positioning time point includes: establishing a clock synchronization protocol for the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, obtaining a reference synchronization time period through the clock synchronization protocol, and the main positioning base station and the auxiliary positioning base station sending time synchronization calibration pulse signals to the mobile terminal at intervals of the reference synchronization time period; generating a discretized time stamp sequence at the mobile intercom terminal, randomly selecting two non-consecutive time nodes from the discretized time stamp sequence and respectively using them as the first positioning time point and the second positioning time point, wherein the time interval between the first positioning time point and the second positioning time point is greater than a preset positioning time interval.

[0007] Optionally, obtaining a first attenuation index according to the first transmission power and the first reception power is expressed as:

[0008] wherein, A1 is the first attenuation index, P t1 is the first transmission power, P r1 is the first reception power, α is an incremental compensation threshold, and β is a scaling ratio.

[0009] Optionally, obtaining a first distance to be processed between the mobile intercom terminal and the main positioning base station according to the first attenuation index is expressed as: Wherein, d1 is the first distance to be processed, c is the speed of light for calculation, f1 is the frequency of the first composite modulation signal, and A1 is the first attenuation index.

[0010] Optionally, the first correction index obtained according to the first reception time and the first positioning time is expressed as: C1 = {T r1 - T p1 - [Δt0 + γ · (T r1 - T p1 )]} · c; wherein, C1 is the first correction index, T r1 is the first reception time, T p1 is the first positioning time, Δt0 is the initial clock synchronization error, γ is the clock drift rate, and c is the speed of light for calculation.

[0011] Optionally, the first target distance obtained according to the first distance to be processed and the first correction index is expressed as: Wherein, D1 is the first target distance, k is the calculation accuracy, C1 is the first correction index, and d1 is the first distance to be processed.

[0012] Optionally, the target positioning data of the mobile intercom terminal obtained according to the first target distance and the second target distance includes: determining the junction area according to the first target distance and the second target distance; obtaining the moving direction of the mobile intercom terminal, and determining the target positioning data of the mobile intercom terminal according to the moving direction and the junction area.

[0013] There is also provided a positioning data transmission system implemented by intercom communication. The system includes: a first acquisition module, configured to acquire a main positioning base station, an auxiliary positioning base station, and a mobile intercom terminal communicating with the base stations, to achieve time synchronization among the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and set a first positioning time point and a second positioning time point; a first data processing module, configured to acquire the first transmission power of a first composite modulation signal sent by the mobile intercom terminal at the first positioning time point, and acquire the first reception time and the first reception power of the first composite modulation signal received by the main positioning base station, and obtain a first attenuation index according to the first transmission power and the first reception power, and obtain a first distance to be processed between the mobile intercom terminal and the main positioning base station according to the first attenuation index, and obtain a first correction index according to the first reception time and the first positioning time, and obtain a first target distance according to the first distance to be processed and the first correction index; a second data processing module, configured to acquire the second transmission power of a second composite modulation signal sent by the mobile intercom terminal at the second positioning time point, and acquire the second reception time and the second reception power of the second composite modulation signal received by the auxiliary positioning base station, and obtain a second attenuation index according to the second transmission power and the second reception power, and obtain a second distance to be processed between the mobile intercom terminal and the auxiliary positioning base station according to the second attenuation index, and obtain a second correction index according to the second reception time and the second positioning time, and obtain a second target distance according to the second distance to be processed and the second correction index; a positioning module, configured to obtain the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance.

[0014] Optionally, the first acquisition module is further configured to: establish a clock synchronization protocol among the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and obtain a reference synchronization time period through the clock synchronization protocol. The main positioning base station and the auxiliary positioning base station send time synchronization calibration pulse signals to the mobile terminal at intervals of the reference synchronization time period; generate a discretized time stamp sequence for the mobile intercom terminal, and randomly select two non-consecutive time nodes from the discretized time stamp sequence and respectively use them as the first positioning time point and the second positioning time point, where the time interval between the first positioning time point and the second positioning time point is greater than a preset positioning time interval.

[0015] Optionally, the positioning module is further configured to: determine a boundary area according to the first target distance and the second target distance; obtain the moving direction of the mobile intercom terminal, and determine the target positioning data of the mobile intercom terminal according to the moving direction and the boundary area.

[0016] The beneficial effects of the present invention are embodied in:

[0017] In the entire positioning data transmission method implemented by intercom communication, through the dynamic clock synchronization protocol and the random time point selection mechanism, the problems of separation between communication and positioning functions and cumulative clock deviation in existing positioning solutions are solved. Further, a dual ranging mechanism that innovatively integrates signal attenuation compensation and dynamic delay correction is adopted. Among them, for signal strength ranging, a non-linear attenuation compensation model is used, combined with the frequency domain characteristics of linear frequency modulation and binary coding in the composite modulation signal, to intelligently distinguish environmental absorption attenuation and multipath interference, and dynamically suppress sudden interference through an adaptive threshold; for time delay ranging, a model for real-time correction of clock drift rate is constructed, and the error is deduced by using two discontinuous positioning time points to maintain the clock synchronization accuracy, so that time difference ranging remains reliable in dynamic scenarios. Further, based on the intelligent data fusion strategy of spatio-temporal continuity, through the heterogeneous observation data of the master and slave base stations and the perception of the moving direction, a three-dimensional motion constraint model is constructed, and the two discrete positioning results are deeply fused with the terminal motion trajectory, effectively solving the problem of cumulative single positioning error. In addition, the random time point selection mechanism and the dynamic weight allocation algorithm form a synergistic advantage, which not only avoids the periodic coupling effect of multipath interference through non-periodic signal transmission, but also adjusts the confidence weight of the ranging method according to the real-time channel quality, so that sub-meter positioning accuracy can still be maintained in strong interference scenarios such as metal shielding and crowded people. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally denoted by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.

[0019] Figure 1 It is a schematic diagram of the steps of the positioning data transmission method implemented by intercom communication according to the present invention in one embodiment;

[0020] Figure 2 It is a schematic diagram of a part of the steps of S1 in the positioning data transmission method implemented by intercom communication according to the present invention;

[0021] Figure 3 It is a schematic diagram of a part of the steps of S4 in the positioning data transmission method implemented by intercom communication according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0023] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0024] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0025] As Figure 1 shown, a positioning data transmission method implemented by intercom communication is provided, including:

[0026] S1. Obtain a primary positioning base station, an auxiliary positioning base station, and a mobile intercom terminal communicating with the base stations, synchronize the time of the primary positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and set a first positioning time point and a second positioning time point;

[0027] S2. Obtain the first transmission power of the first composite modulation signal sent by the mobile intercom terminal at the first positioning time point, obtain the first reception time and the first reception power of the first composite modulation signal received by the primary positioning base station, obtain a first attenuation index according to the first transmission power and the first reception power, obtain a first to-be-processed distance between the mobile intercom terminal and the primary positioning base station according to the first attenuation index, obtain a first correction index according to the first reception time and the first positioning time, and obtain a first target distance according to the first to-be-processed distance and the first correction index;

[0028] S3. Obtain the second transmission power of the second composite modulation signal sent by the mobile intercom terminal at the second positioning time point, obtain the second reception time and the second reception power of the second composite modulation signal received by the auxiliary positioning base station, obtain a second attenuation index according to the second transmission power and the second reception power, obtain a second to-be-processed distance between the mobile intercom terminal and the auxiliary positioning base station according to the second attenuation index, obtain a second correction index according to the second reception time and the second positioning time, and obtain a second target distance according to the second to-be-processed distance and the second correction index;

[0029] S4. Obtain the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance.

[0030] In this embodiment, it should be noted that in S1, through the dynamic clock synchronization protocol and the random time point selection mechanism, the problems of separation between communication and positioning functions and cumulative clock deviation in the existing positioning solutions are solved. Specifically, the master positioning base station and the auxiliary positioning base station can send time synchronization calibration pulse signals to the mobile intercom terminal at a cycle of the reference synchronization time period; in this process, an adaptive clock synchronization strategy is adopted. For example, in an industrial environment with strong signal interference, the base station can dynamically shorten the synchronization interval according to the real-time channel quality, and ensure that the mobile terminal and the base station maintain microsecond-level clock alignment by iteratively adjusting the transmission frequency of the pulse signal, while correcting the timing error caused by the Doppler effect or the hardware crystal oscillator deviation, so as to maintain global time consistency in a complex environment.

[0031] Furthermore, after synchronization, the mobile intercom terminal generates a discretized timestamp sequence, and two non-consecutive time nodes are selected from the sequence as the transmission moments of the positioning signals through a pseudo-random algorithm. For example, in a fire rescue scenario, the terminal uses a hash function combined with environmental noise characteristics in the timestamp pool to generate unpredictable candidate time points, and eliminates the nodes with an interval less than a preset threshold to ensure that the interval between two signal transmissions is large enough. This design avoids the problem that periodic signals are easily interfered on the one hand, and reduces the coupled influence of multipath effects and dynamic movement on a single ranging result through time dispersion on the other hand. For example, the terminal will select time points that are several seconds apart and irregular to send signals, enabling the master and auxiliary base stations to capture signals in different spatial states, providing input with time sequence differentiation for subsequent fusion of multi-dimensional ranging data, thereby improving the robustness of dynamic target tracking.

[0032] In S2, through the dual mechanisms of fusing signal attenuation compensation and clock dynamic correction, the problem of insufficient accuracy of a single ranging method in a complex environment is solved. When the mobile intercom terminal sends a composite modulation signal at the first positioning time point, the master positioning base station will synchronously record the transmission power and reception power of the signal, and calculate the attenuation index through a non-linear compensation model. For example, in an industrial workshop with metal equipment occlusion, the signal may experience a sudden drop in reception power due to multipath reflection and penetration loss. At this time, the attenuation weight will be dynamically adjusted according to a preset incremental compensation threshold. When the difference between the transmission and reception powers exceeds the threshold, the interference of abnormal attenuation caused by environmental mutations on distance estimation will be automatically reduced, thus avoiding signal strength ranging distortion caused by wall absorption or equipment occlusion. At the same time, combining the frequency characteristics of the composite modulation signal, the attenuation index is converted into a preliminary distance estimation value. This process comprehensively considers the differences in the penetrability of signals in different frequency bands and the ability to suppress multipath. For example, the low-frequency component is used to compensate for the attenuation deviation of the high-frequency signal caused by metal reflection.

[0033] Furthermore, the reliability of time-delay ranging is improved through dynamic modeling and real-time correction of clock errors. The master base station iteratively corrects the propagation delay according to the time difference between the reception time and the positioning time, in combination with the initial synchronization error and the clock drift rate. For example, in the scenario where a firefighter carries a terminal, the Doppler effect and terminal vibration may cause the crystal oscillator frequency to shift. By introducing a drift rate parameter to perform non-linear compensation on the time difference, the clock cumulative error caused by terminal movement is eliminated. Finally, by adaptively weighted fusion of the signal strength ranging result and the distance estimate after time-delay correction, the confidence weights of the two ranging methods can be automatically adjusted in scenarios of signal mutation or clock misalignment. For example, when the signal is temporarily blocked by an obstacle, the weight of time-delay ranging is increased, while when the multipath interference is severe, the signal strength ranging result after attenuation compensation is relied on preferentially, so as to achieve high-precision distance estimation in a dynamic and complex environment.

[0034] In S3, the data processing process and model usage are the same as in S2. Through heterogeneous data fusion and spatio-temporal difference analysis of the auxiliary positioning base station, the positioning robustness in a dynamic scenario is further enhanced. When the mobile intercom terminal sends a second composite modulation signal at the second positioning time point, the auxiliary positioning base station will synchronously capture the propagation characteristics of the signal. However, due to the difference in its spatial position from the master base station, the environmental interference patterns of the signal propagation paths are also different. For example, in the scenario of chemical plant inspection, if the signal of the master base station is severely attenuated due to passing through the metal shell of the reactor, while the auxiliary base station is located in an open corridor area, on the premise of the same position, different times, and different positioning base stations, the signal attenuation characteristics in different spatial dimensions are ensured to be differentially processed, avoiding distance estimation deviation caused by a single environment and a single spatial dimension, and enabling the precise position information of the mobile intercom terminal to be inferred by combining the geometric relationship between the two positioning moments.

[0035] In S4, first, based on the first and second target distances measured by the master and auxiliary base stations respectively, a dynamic overlapping area centered on the two base stations with the distances as the radii will be constructed, and this area deforms in real time according to the terminal movement state. For example, in the scenario of tunnel fire rescue, when the firefighter is in a curved passage, multiple false intersection points may be generated in the annular area formed by the two ranging measurements. At this time, the spatial probability distribution of the overlapping area will be modeled by combining the subsequent moving direction sensor data of the mobile intercom terminal (such as the heading angle change rate of the inertial navigation unit), and the positioning point will be preferentially locked on the extending direction of the passage that conforms to the movement trend, while excluding the candidate points in the reverse area caused by signal reflection, so as to achieve precise positioning under path constraints in complex terrain. Specifically, by analyzing the velocity change characteristics within the time interval between the two positioning times, the fusion weight of the distance measurement value and the motion prediction value can be dynamically adjusted, and the position that best matches the current environmental characteristics of the signal propagation path is preferentially selected as the final positioning result, so as to achieve the optimal fusion of multi-dimensional data in a dynamic environment.

[0036] In summary, in the entire positioning data transmission method implemented by intercom communication, through the dynamic clock synchronization protocol and the random time point selection mechanism, the problems of separation between communication and positioning functions and cumulative clock deviation in existing positioning solutions are solved. Further, a dual ranging mechanism that innovatively integrates signal attenuation compensation and dynamic delay correction is adopted. Among them, for signal strength ranging, a non-linear attenuation compensation model is used, combined with the frequency domain characteristics of linear frequency modulation and binary coding in the composite modulation signal, to intelligently distinguish environmental absorption attenuation and multipath interference, and dynamically suppress sudden interference through an adaptive threshold; for time delay ranging, a model for real-time correction of clock drift rate is constructed, and the error is deduced by using two discontinuous positioning time points to maintain the clock synchronization accuracy, so that the time difference ranging remains reliable in dynamic scenarios. Further, based on the intelligent data fusion strategy of spatio-temporal continuity, through the heterogeneous observation data of the main and auxiliary base stations and the perception of the moving direction, a three-dimensional motion constraint model is constructed, and the two discrete positioning results are deeply fused with the terminal motion trajectory, effectively solving the problem of cumulative single positioning error. In addition, the random time point selection mechanism and the dynamic weight allocation algorithm form a synergistic advantage, which not only avoids the periodic coupling effect of multipath interference through non-periodic signal transmission, but also adjusts the confidence weight of the ranging method according to the real-time channel quality, so that sub-meter positioning accuracy can still be maintained in strong interference scenarios such as metal shielding and crowded people.

[0037] As Figure 2 shown, in one embodiment, implementing time synchronization of the main positioning base station, the auxiliary positioning base station and the mobile intercom terminal and setting the first positioning time point and the second positioning time point in S1 includes:

[0038] S11. Establish a clock synchronization protocol for the main positioning base station, the auxiliary positioning base station and the mobile intercom terminal, and obtain a reference synchronization time period through the clock synchronization protocol. The main positioning base station and the auxiliary positioning base station send time synchronization calibration pulse signals to the mobile terminal at intervals of the reference synchronization time period.

[0039] S12. Generate a discretized timestamp sequence at the mobile intercom terminal, randomly select two non-consecutive time nodes from the discretized timestamp sequence and use them as the first positioning time point and the second positioning time point respectively, where the time interval between the first positioning time point and the second positioning time point is greater than a preset positioning time interval.

[0040] In this embodiment, it should be noted that in S11, by constructing a global time reference through adaptive clock synchronization, the problem of cumulative clock drift in multi-device collaborative positioning is solved. The master and slave base stations send time calibration pulse signals to the mobile terminal at a dynamically adjusted reference time period, and their synchronization frequency is intelligently adjusted according to the real-time channel quality. For example, in an industrial scenario with dense chemical equipment, the reflection of wireless signals by metal pipes will cause severe fluctuations in channel quality. At this time, the base station will detect the intensity of multipath interference through the spectrum sensing module, automatically compress the synchronization interval from the conventional second level to the sub-second level, and at the same time use the two-way time calibration algorithm in the existing technology to eliminate the asymmetry of transmission delay - that is, the mobile terminal immediately returns a response signal with a local timestamp after receiving the pulse, and the base station dynamically corrects the linear clock offset caused by the crystal oscillator deviation by calculating the statistical distribution of the round-trip delay, ensuring that the time alignment accuracy at the microsecond level is maintained, providing a reliable time reference for subsequent time-delay ranging.

[0041] In S12, after clock synchronization, the terminal discretizes the time axis into a time slot sequence with a millisecond-level accuracy, and generates a random number seed based on environmental noise characteristics (such as electromagnetic interference intensity, sensor data), and screens out multiple candidate time nodes in the time slot sequence through an encryption hash function. For example, in a tunnel fire rescue scenario, the terminal collects environmental parameters such as the residual WiFi signal and the baseband noise of the walkie-talkie channel in the tunnel, generates a noise fingerprint with spatial uniqueness, drives the pseudo-random algorithm to generate a set of time nodes that cannot be predicted externally, and then selects two optimal time points according to the preset anti-collision rules (such as minimum time interval constraint, signal transmission energy consumption threshold). This mechanism not only ensures the unpredictability of the signal transmission time, avoids the periodic superposition interference of the fixed-period signal by the multipath reflected waves, but also enables the master and slave base stations to capture the signal during the period when the terminal displacement changes significantly by forcing time dispersion, providing spatio-temporal differentiated observation data for motion trajectory reconstruction.

[0042] In one embodiment, the first attenuation index obtained according to the first transmission power and the first reception power in S2 is expressed as:

[0043] Among them,

[0044] A1 is the first attenuation index, P t1 is the first transmission power, P r1 is the first reception power, α is the incremental compensation threshold, and β is the scaling ratio.

[0045] In this embodiment, it should be noted that (P t1 -P r1 ) is the first transmission power P t1 and the first reception power P r1The difference reflects the total attenuation of the signal along the propagation path, including free space loss and environmental absorption / reflection loss. This is the fundamental basis for signal strength ranging.

[0046] Furthermore, is the non-linear compensation term. Among them, max{0, P t1 -P r1 -α} is the threshold determination. When the power difference P t1 -P r1 exceeds the incremental compensation threshold α, it is considered that an abnormal attenuation is caused by an environmental mutation (such as metal occlusion, wall penetration), and the compensation mechanism needs to be activated; the threshold α is set according to the measured data of typical scenarios (such as industrial plants, fire rescue) to distinguish normal attenuation from abnormal attenuation. The exponential attenuation compensation e^(-β * compensation amount). When P t1 -P r1 exceeds α, β controls the compensation amplitude, and the exponential function makes the compensation amount decrease non-linearly with the increase; the smaller the β value, the milder the suppression of abnormal attenuation; the larger the β value, the more radical the suppression; this design avoids the overcorrection problem that may be caused by linear compensation.

[0047] Furthermore, in a complex environment, the signal may experience a sudden increase in P t1 -P r1 due to multipath reflection or penetration loss. Traditional RSSI ranging directly uses P t1 -P r1 to calculate the distance, which will overestimate the actual distance due to abnormal attenuation (for example, misjudging a short distance as a long distance). This expression identifies the abnormal state through the threshold α and uses the exponential term to reduce the effective weight of P t1 -P r1 to suppress the ranging distortion caused by environmental mutations.

[0048] When P t1 -P r1 ≤α: max{0, P t1 -P r1 -α} = 0, the exponential term is 1, and the expression degenerates to A1 = (P t1 -P r1 ), retaining the basic attenuation value, which is applicable to free space or weak interference scenarios.

[0049] When P t1 -P r1 >α: the exponential term takes effect. For example, when P t1 -P r1 = α + 10dB, A1 = (P t1 -P r1 )·e -10β, significantly reducing the impact of abnormal attenuation; this dynamic adjustment enables the algorithm to adaptively switch between normal and abnormal environments, avoiding the limitations of fixed compensation strategies.

[0050] Furthermore, by adjusting α and β, different environmental characteristics can be adapted: Industrial scenarios (with a lot of metal shielding): Set α to be smaller (e.g., 15 dB) and β to be larger (e.g., 0.05) to quickly suppress strong attenuation; Fire rescue (with a lot of wall penetration): Set α to be medium (e.g., 20 dB) and β to be smaller (e.g., 0.01) to balance penetration loss and multipath interference.

[0051] For example: During the inspection of a chemical plant, there is a metal reactor shielding between the mobile terminal and the main base station, resulting in abnormal signal attenuation. Parameter settings: α = 15 dB (typical metal shielding threshold), β = 0.01 (gentle suppression). Measured data: Transmit power P t1 = 30 dBm, received power P r1 = 8 dBm.

[0052] Calculation process: P t1 -P r1 = 22 dB, determine max{0, P t1 -P r1 -α} = 7, then the non-linear compensation term is e -0.01*7 ≈ 0.93, and the final attenuation index A1 = 22 × 0.93 ≈ 20.5.

[0053] Existing method: Directly use P t1 -P r1 = 22 dB to calculate the distance, and due to metal shielding, the distance is overestimated by about 10%. This solution: The equivalent attenuation A1 ≈ 20.5 dB, the conversion distance error is reduced, and the impact of metal interference is significantly suppressed.

[0054] In one embodiment, the first distance to be processed between the mobile intercom terminal and the main positioning base station obtained according to the first attenuation index in S2 is expressed as:

[0055] Among them,

[0056] d1 is the first distance to be processed, c is the speed of light for calculation, f1 is the frequency of the first composite modulation signal, and A1 is the first attenuation index.

[0057] In this embodiment, it should be noted that by introducing a frequency dependence and a log-linear conversion mechanism, the entire expression solves the systematic error problem caused by ignoring the frequency band characteristics in traditional signal strength ranging in complex environments. Among them, c / (4πf1) is derived from the electromagnetic wave free space path loss model, representing the propagation characteristics of a signal with a wavelength of λ = c / f1 in an ideal non-attenuating environment. This part provides a theoretical basis for distance calculation, binds the signal frequency to the speed of light, and reflects the differences in the signal propagation capabilities of different frequency bands.

[0058] Furthermore, For the attenuation index conversion, the unit of the attenuation index A1 is dB (decibel), and it needs to be converted into a linear ratio through exponential operation. The coefficient design of is derived from the conversion relationship between power and voltage: in the path loss formula, the relationship between power attenuation (dB) and distance is A1 = 20log 10 (d1 / d0), where d0 = c / (4πf1) is the reference distance. By performing the exponential operation 10^(A1 / 20), the decibel value is restored to the actual distance multiple, that is,

[0059] To sum up, in complex environments, the signals of different frequency bands are significantly affected by the multipath effect and penetration loss; for example: low-frequency signals (such as 500 MHz) have strong penetration ability but are easily interfered by metal reflections; high-frequency signals (such as 2.4 GHz) have good directivity but are easily absorbed by walls. The f1 in the formula corresponds to the center frequency of the composite modulation signal, and it automatically adapts to the propagation characteristics of the current frequency band through c / (4πf1), avoiding the systematic deviation caused by the fixed frequency model of traditional RSSI ranging. Furthermore, the broadband characteristics of the composite modulation signal (linear frequency modulation + binary coding) enable the signal spectrum to cover multiple sub-frequency bands. By selecting f1 (such as selecting the sub-carrier frequency with the best penetration), the formula preferentially uses the frequency band less affected by the environment to calculate the distance; for example: when the signal passes through a metal partition, a low-frequency sub-carrier is selected to calculate the distance to compensate for the excessive attenuation of the high-frequency component; when the signal propagates in an open space, a high-frequency sub-carrier is selected to calculate the distance and utilize its anti-multipath reflection ability. Furthermore, through the real-time updated f1 (the actual transmission frequency of the composite modulation signal) and the corrected A1 (the attenuation value after suppressing abnormal attenuation), the formula can dynamically adapt to environmental changes; for example: when a firefighter passes through walls of different materials, the frequency band with the smallest current penetration loss is automatically selected as f1; when a metal device temporarily blocks the signal, the influence of the failure of this frequency band on ranging is reduced through the non-linear compensation of A1.

[0060] In one embodiment, the first correction index obtained according to the first reception time and the first positioning time in S2 is expressed as:

[0061] C1 = {T r1 -Tp1 -[Δt0 + γ·(T r1 -T p1 )]}·c; where,

[0062] C1 is the first correction index, T r1 is the first reception time, T p1 is the first positioning time, Δt0 is the initial clock synchronization error, γ is the clock drift rate, and c is the speed of light for calculation.

[0063] In this embodiment, it should be noted that the entire expression solves the problems of Doppler frequency shift and clock cumulative error caused by terminal movement in time difference of arrival ranging through dynamic clock error modeling and non-linear drift compensation. Among them, the basic time delay extraction (T r1 -T p1 ), the difference between the reception time T r1 and the positioning time T p1 reflects the sum of the signal propagation time and the clock error, which is the original input of time difference of arrival ranging. The initial clock synchronization error (Δt0), Δt0 comes from the residual error of the time synchronization protocol, and this value is directly deducted to eliminate the influence of the misalignment between the base station and the terminal at the initial moment. Dynamic drift compensation (γ·(T r1 -T p1 ))), the clock drift rate γ describes the clock cumulative error rate caused by the frequency deviation of the terminal crystal oscillator (such as 10 ppm means a deviation of 10 μs per second), γ·(T r1 -T p1 ) represents the drift accumulation from the synchronization moment to the current moment, and dynamically corrects the frequency offset of the crystal oscillator caused by terminal movement (vibration, temperature change). Speed of light conversion (c): Converts the corrected time difference into a distance dimension and fuses it with the signal strength ranging result.

[0064] In summary, the time delay error caused by this frequency shift is compensated in real time through γ·(T r1 -T p1 ), avoiding the wrong stretching of the positioning result. Traditional time difference of arrival ranging ignores clock drift, assuming γ = 0. In long-term positioning (such as a 30-second interval), if γ = 10 ppm, the cumulative error reaches 300 μs, corresponding to a distance error exceeding 90 km. This formula suppresses the error to the centimeter level through dynamic γ modeling. γ can be extended to a time-varying function γ(t) and is dynamically updated through the data of the terminal acceleration sensor. For example: in the high-temperature area of a chemical plant, the drift of the crystal oscillator is aggravated by heat, and the γ weight is increased according to the feedback of the temperature sensor.

[0065] In one embodiment, obtaining the first target distance according to the first distance to be processed and the first correction index in S2 is expressed as:

[0066] where,

[0067] Let D1 be the first target distance, k be the calculation accuracy, C1 be the first correction index, and d1 be the first distance to be processed.

[0068] In this embodiment, it should be noted that the expression solves the problem of insufficient reliability of a single ranging method in a dynamic and complex environment through an adaptive weight fusion strategy, achieving the complementary advantages of signal strength ranging and time-delay ranging. Among them, d1 is the distance estimation based on signal attenuation compensation, which reflects the environmental attenuation characteristics but is vulnerable to multipath interference; C1 is the time-delay ranging result based on dynamic clock correction, which is anti-attenuation but depends on the clock synchronization accuracy; the expression fuses two types of heterogeneous data through weighted average and utilizes the difference in their error distributions to improve the overall robustness.

[0069] Furthermore, the weight coefficient k satisfies 1 ≥ k > 0, representing the confidence weight of the time-delay ranging result. The larger the k value, the more the system trusts the time-delay ranging; 1 / (k + 1) is the normalization factor to ensure that the sum of weights is 1 and avoid scale distortion; at the same time, the k value can be dynamically calculated according to the real-time channel quality. When the signal suddenly changes (such as temporary occlusion), increase the k value (approaching 1) and preferentially use the time-delay ranging; when the multipath interference is severe, decrease the k value (approaching 0) and rely on the signal strength ranging after attenuation compensation.

[0070] For example, in an industrial scenario with a dense metal equipment, the signal reflection causes d1 to significantly overestimate the real distance. For example: d1 = 50 meters (due to the superposition of metal reflection paths), C1 = 30 meters (the time-delay ranging captures the direct path); set k = 0.8, and the fusion result D1 = (0.8×30 + 50) / 1.8 ≈ 36.67 meters, reducing the error by 26.6% compared to d1. When causing an error in time-delay ranging, suppress the anomaly by reducing the k value: C1 = 60 meters (producing a 10-meter error due to crystal oscillator drift), d1 = 45 meters; set k = 0.3, D1 = (0.3×60 + 45) / 1.3 ≈ 46.15 meters, reducing the error by 76.9% compared to C1. Dynamically calculate k according to the spectral characteristics of the composite modulation signal: when the low-frequency subcarrier has strong penetration, increase the weight of d1 (k decreases); when the high-frequency subcarrier resists multipath, increase the weight of C1 (k increases).

[0071] As Figure 3 shown, in one embodiment, obtaining the target location data of the mobile intercom terminal according to the first target distance and the second target distance in S4 includes:

[0072] S41. Determine the intersection area according to the first target distance and the second target distance;

[0073] S42. Obtain the moving direction of the mobile intercom terminal, and determine the target location data of the mobile intercom terminal according to the moving direction and the intersection area.

[0074] In this embodiment, it should be noted that in S41, the problem of positioning ambiguity caused by multipath effects is solved through multi-base station spatial geometric constraints and dynamic probability modeling. Based on the target distances measured by the primary and secondary base stations, distance circular regions centered on each base station are respectively constructed, and the overlapping regions are calculated using the spatial position relationship between the base stations. For example, in the scenario of chemical plant inspection, if metal pipes cause signal reflections to form multiple false intersection points, the spectral characteristics of the two ranging signals (such as the time delay difference between the direct path and the reflected path) will be analyzed, and a three-dimensional probability density model will be established in combination with the base stations. Candidate regions where the signal propagation path is consistent with the line-of-sight direction of the base station will be preferentially screened, and at the same time, the overlapping regions will be weighted and shrunk in real time, so as to accurately narrow the possible space range of the target in a strong multipath environment.

[0075] In S42, continuous tracking of dynamic targets is achieved through motion trajectory fitting and direction perception optimization. When there are multiple possible positions in the intersection region, the nine-axis inertial sensor (including accelerometer, gyroscope, magnetometer) built into the terminal collects motion direction and angular velocity data in real time to predict the displacement vector in the next few milliseconds. For example, when a firefighter turns in a tunnel, the curvature of the motion trajectory is inferred from the change rate of the heading angle, the candidate positioning points are projected onto the extended line of the motion trend, and the spatio-temporal continuity between each candidate point and the historical trajectory is analyzed - the point with the highest matching degree between the signal propagation loss and the motion speed within the path constraint range is preferentially selected as the final positioning result. At the same time, the system dynamically adjusts the weight of the motion model according to environmental characteristics (such as the reflection coefficient of the metal wall), emphasizing inertial navigation data in open spaces and signal propagation path analysis in complex structure areas, so as to achieve centimeter-level dynamic tracking accuracy.

[0076] A positioning data transmission system implemented by intercom communication is also provided. The system includes:

[0077] A first acquisition module, which is used to acquire the primary positioning base station, the auxiliary positioning base station, and the mobile intercom terminal communicating with the base stations, realize time synchronization of the primary positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and set the first positioning time point and the second positioning time point;

[0078] A first data processing module, which is used to acquire the first transmission power of the first composite modulation signal sent by the mobile intercom terminal at the first positioning time point, acquire the first reception time and the first reception power of the first composite modulation signal received by the primary positioning base station, obtain the first attenuation index according to the first transmission power and the first reception power, obtain the first distance to be processed between the mobile intercom terminal and the primary positioning base station according to the first attenuation index, obtain the first correction index according to the first reception time and the first positioning time, and obtain the first target distance according to the first distance to be processed and the first correction index;

[0079] A second data processing module, configured to obtain the second transmission power of the second composite modulation signal sent by the mobile intercom terminal at the second positioning time point, obtain the second reception time and the second reception power of the second composite modulation signal received by the main positioning base station, obtain a second attenuation index according to the second transmission power and the second reception power, obtain a second distance to be processed between the mobile intercom terminal and the main positioning base station according to the second attenuation index, obtain a second correction index according to the second reception time and the second positioning time, and obtain a second target distance according to the second distance to be processed and the second correction index;

[0080] A positioning module, configured to obtain the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance.

[0081] In one embodiment, the first acquisition module is further configured to: establish a clock synchronization protocol among the main positioning base station, the auxiliary positioning base station and the mobile intercom terminal, obtain a reference synchronization time period through the clock synchronization protocol, and the main positioning base station and the auxiliary positioning base station send time synchronization calibration pulse signals to the mobile terminal at intervals of the reference synchronization time period; generate a discretized timestamp sequence at the mobile intercom terminal, randomly select two non-consecutive time nodes from the discretized timestamp sequence and respectively use them as the first positioning time point and the second positioning time point, wherein the time interval between the first positioning time point and the second positioning time point is greater than a preset positioning time interval.

[0082] In one embodiment, the positioning module is further configured to: determine a boundary area according to the first target distance and the second target distance; obtain the moving direction of the mobile intercom terminal, and determine the target positioning data of the mobile intercom terminal according to the moving direction and the boundary area.

[0083] In this embodiment, it should be noted that regarding the above positioning data transmission system implemented by intercom communication, the specific implementation manners of the operations have been described in detail in the embodiments of the positioning data transmission method implemented by intercom communication, and will not be elaborated herein.

[0084] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept scope of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0085] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination manners.

[0086] In addition, any combination can be made among various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the specification of the present invention.

Claims

1. A positioning data transmission method implemented by intercom communication, characterized in that, Including: Obtain the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal communicating with the base stations, synchronize the time of the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and set the first positioning time point and the second positioning time point; Obtain the first transmission power of the first composite modulation signal sent by the mobile intercom terminal at the first positioning time point, obtain the first reception time and the first reception power of the first composite modulation signal received by the main positioning base station, obtain the first attenuation index according to the first transmission power and the first reception power, obtain the first distance to be processed between the mobile intercom terminal and the main positioning base station according to the first attenuation index, obtain the first correction index according to the first reception time and the first positioning time, and obtain the first target distance according to the first distance to be processed and the first correction index; Obtain the second transmission power of the second composite modulation signal sent by the mobile intercom terminal at the second positioning time point, obtain the second reception time and the second reception power of the second composite modulation signal received by the auxiliary positioning base station, obtain the second attenuation index according to the second transmission power and the second reception power, obtain the second distance to be processed between the mobile intercom terminal and the auxiliary positioning base station according to the second attenuation index, obtain the second correction index according to the second reception time and the second positioning time, and obtain the second target distance according to the second distance to be processed and the second correction index; Obtain the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance.

2. The positioning data transmission method implemented by intercom communication according to claim 1, wherein The implementation of time synchronization of the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal and setting the first positioning time point and the second positioning time point includes: Establish a clock synchronization protocol for the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, obtain a reference synchronization time period through the clock synchronization protocol, and the main positioning base station and the auxiliary positioning base station send time synchronization calibration pulse signals to the mobile terminal every other reference synchronization time period; Generate a discretized timestamp sequence at the mobile intercom terminal, randomly select two non-consecutive time nodes from the discretized timestamp sequence and use them as the first positioning time point and the second positioning time point respectively, wherein the time interval between the first positioning time point and the second positioning time point is greater than a preset positioning time interval.

3. The positioning data transmission method implemented by intercom communication according to claim 1, wherein The obtaining of the first attenuation index according to the first transmission power and the first reception power is expressed as: Among them, A1 is the first attenuation index, P t1 is the first transmission power, P r1 is the first reception power, α is the incremental compensation threshold, and β is the scaling ratio.

4. The positioning data transmission method implemented by intercom communication according to claim 1, wherein The obtaining of the first distance to be processed between the mobile intercom terminal and the main positioning base station according to the first attenuation index is expressed as: Among them, d1 is the first distance to be processed, c is the speed of light for calculation, f1 is the frequency of the first composite modulation signal, and A1 is the first attenuation index.

5. The positioning data transmission method implemented by intercom communication according to claim 1, characterized in that The obtaining of the first correction index according to the first reception time and the first positioning time is expressed as: C1 = {T r1 -T p1 -[Δt0 + γ·(T r1 -T p1 )]}·c; wherein, C1 is the first correction index, T r1 is the first reception time, T p1 is the first positioning time, Δt0 is the initial clock synchronization error, γ is the clock drift rate, and c is the speed of light for calculation.

6. The positioning data transmission method implemented by intercom communication according to claim 1, wherein The obtaining of the first target distance according to the first distance to be processed and the first correction index is expressed as: Among them, D1 is the first target distance, k is the calculation accuracy, C1 is the first correction index, and d1 is the first distance to be processed.

7. The positioning data transmission method implemented by intercom communication according to claim 1, characterized in that, The obtaining of the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance includes: Determine the intersection area according to the first target distance and the second target distance; Obtain the moving direction of the mobile intercom terminal, and determine the target positioning data of the mobile intercom terminal according to the moving direction and the junction area.

8. A positioning data transmission system implemented by intercom communication, characterized in that, The system includes: A first acquisition module, configured to acquire the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal communicating with the base stations, implement time synchronization of the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and set a first positioning time point and a second positioning time point; A first data processing module, configured to acquire the first transmission power of the first composite modulation signal sent by the mobile intercom terminal at the first positioning time point, and acquire the first reception time and the first reception power of the first composite modulation signal received by the main positioning base station, and obtain a first attenuation index according to the first transmission power and the first reception power, and obtain a first distance to be processed between the mobile intercom terminal and the main positioning base station according to the first attenuation index, and obtain a first correction index according to the first reception time and the first positioning time, and obtain a first target distance according to the first distance to be processed and the first correction index; A second data processing module, configured to acquire the second transmission power of the second composite modulation signal sent by the mobile intercom terminal at the second positioning time point, and acquire the second reception time and the second reception power of the second composite modulation signal received by the auxiliary positioning base station, and obtain a second attenuation index according to the second transmission power and the second reception power, and obtain a second distance to be processed between the mobile intercom terminal and the auxiliary positioning base station according to the second attenuation index, and obtain a second correction index according to the second reception time and the second positioning time, and obtain a second target distance according to the second distance to be processed and the second correction index; A positioning module, configured to obtain the target positioning data of the mobile intercom terminal according to the first target distance and the second target distance.

9. The positioning data transmission system implemented by intercom communication according to claim 8, wherein The first acquisition module is further configured to: Establish a clock synchronization protocol for the main positioning base station, the auxiliary positioning base station, and the mobile intercom terminal, and obtain a reference synchronization time period through the clock synchronization protocol. The main positioning base station and the auxiliary positioning base station send time synchronization calibration pulse signals to the mobile terminal at intervals of the reference synchronization time period; Generate a discretized timestamp sequence for the mobile intercom terminal, randomly select two non-consecutive time nodes from the discretized timestamp sequence and respectively use them as the first positioning time point and the second positioning time point, where the time interval between the first positioning time point and the second positioning time point is greater than a preset positioning time interval.

10. The positioning data transmission system implemented by intercom communication according to claim 8, characterized in that, The positioning module is further configured to: Determine the junction area according to the first target distance and the second target distance; Obtain the moving direction of the mobile intercom terminal, and determine the target positioning data of the mobile intercom terminal according to the moving direction and the junction area.

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