An indoor positioning system for fire safety evacuation

Abstract

The application discloses a kind of indoor positioning systems for fire safety evacuation, it is related to fire safety technical field, the indoor positioning system includes positioning terminal, wireless communication module, server and fire equipment control module, positioning terminal is worn on the body of indoor personnel, for real-time acquisition personnel's position information, and position information is sent to server by wireless communication module, server receives position information, and personnel is positioned according to stored high-precision indoor map, simultaneously, server also sends personnel's position information to fire equipment control module, to make fire equipment control module control the operation of fire equipment according to personnel position information, the indoor positioning system for fire safety evacuation of the application has very high positioning accuracy and reliability, positioning terminal uses ultra-wideband UWB positioning technology, can accurately determine personnel position in complex indoor environment.

Description

Technical Field

[0001] This invention relates to the field of fire safety technology, specifically to an indoor positioning system for fire safety evacuation. Background Technology

[0002] In fire safety evacuation, accurately and quickly determining the location of people and guiding them to evacuate safely is crucial. Evacuation time is extremely precious in emergencies such as fires; every second can be a matter of life and death. Therefore, an efficient and reliable indoor positioning system is of great importance in ensuring that people can quickly find the nearest safe exit and evacuate smoothly. As building structures become increasingly complex, traditional evacuation signs and manual guidance are no longer sufficient to meet the needs of modern fire safety. This necessitates the use of more advanced technologies to improve evacuation efficiency and safety.

[0003] However, existing indoor positioning systems mostly rely on RFID (Radio Frequency Identification), Wi-Fi signal strength, and Bluetooth positioning technologies. These technologies are easily affected by signal interference in emergency situations. For example, dense smoke and flames can absorb or reflect wireless signals, causing signal attenuation or even interruption, thus affecting positioning accuracy. Furthermore, in complex environments, such as walls, metal structures, and other obstacles inside buildings, wireless signals can be shielded and reflected, further reducing the reliability of positioning and resulting in larger positioning errors. Moreover, large-scale applications require extensive infrastructure support, which is often difficult to achieve.

[0004] In summary, existing indoor positioning technologies have significant shortcomings in fire safety evacuation and cannot meet the demand for rapid and accurate location of personnel in emergency situations. Therefore, developing a new type of indoor positioning system for fire safety evacuation based on ultra-wideband positioning technology to overcome the deficiencies of existing technologies and improve positioning accuracy, reliability, and real-time performance is of great practical significance and urgency. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an indoor positioning system for fire safety evacuation. This system significantly improves the positioning accuracy and stability in emergency situations such as fires by introducing innovative ultra-wideband (UWB) positioning technology. It can also effectively penetrate smoke and flames in complex indoor environments, maintain stable signal transmission, and ensure accurate and rapid determination of personnel location in emergency situations.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an indoor positioning system for fire safety evacuation, comprising a positioning terminal, a wireless communication module, a server, and a fire equipment control module. The positioning terminal is worn by people indoors to collect their location information in real time and transmits the location information to the server via the wireless communication module. The server receives the location information and locates the people based on a stored high-precision indoor map. Simultaneously, the server also transmits the people's location information to the fire equipment control module, so that the fire equipment control module controls the operation of the fire equipment based on the people's location information.

[0007] The positioning terminal is worn by people indoors and uses ultra-wideband (UWB) positioning technology to accurately determine the specific location of people indoors. It includes a microprocessor, a UWB positioning module, and a power module. The UWB positioning module can measure the distance between people and surrounding base stations and determine the location of people through a triangulation algorithm. After the microprocessor processes the location information, it sends the location information to the server through a wireless communication module. The power module provides power to the positioning terminal.

[0008] The wireless communication module is responsible for establishing a data transmission channel between the positioning terminal and the server;

[0009] The server includes a database, a map management module, and a positioning calculation module. The database is used to store high-precision indoor maps and personnel location information. The map management module is responsible for managing and updating the high-precision indoor maps. The positioning calculation module performs positioning calculations on personnel based on the location information sent by the positioning terminal and the high-precision indoor maps to determine the specific location of personnel indoors.

[0010] The fire protection equipment control module includes a fire alarm controller, a fire linkage controller, and fire protection equipment. The fire alarm controller receives fire alarm signals and sends them to the fire linkage controller. The fire linkage controller controls the operation of the fire protection equipment based on the location information of personnel and the fire alarm signals.

[0011] The server's map management module and positioning calculation module can work with UWB positioning technology. Specifically, the map management module updates a high-precision indoor map in real time based on the location information of the UWB positioning terminal, and the positioning calculation module uses UWB positioning technology to quickly and accurately calculate the location of people.

[0012] The fire equipment control module can intelligently control the operation of fire equipment based on personnel location information provided by ultra-wideband positioning technology.

[0013] Furthermore, the UWB positioning module in the positioning terminal includes a signal transmitter, a signal receiver, a distance calculation unit, a positioning algorithm processor, a synchronization and calibration unit, and an interface circuit, wherein:

[0014] The signal transmitter is used to transmit ultra-wideband signals for effective positioning in complex indoor environments.

[0015] The signal receiver is used to receive ultra-wideband signals from surrounding base stations and other positioning terminals;

[0016] The distance calculation unit calculates the distance between the positioning terminal and surrounding base stations based on the signal received by the signal receiver and the signal propagation speed, using the time difference measurement principle.

[0017] The positioning algorithm processor receives distance data output by the distance calculation unit and, in conjunction with the triangulation algorithm, calculates the specific coordinates of the positioning terminal indoors.

[0018] The synchronization and calibration unit is used to ensure time synchronization between the positioning terminal and surrounding base stations, and to perform system calibration.

[0019] The interface circuit is used to transmit the location information calculated by the positioning algorithm processor to the microprocessor of the positioning terminal.

[0020] Furthermore, the distance calculation unit uses the signal transmitter and receiver to record the timestamps of the UWB signals transmitted by the positioning terminal and received from surrounding base stations. It employs bidirectional time difference measurement (TT&T) technology to calculate the distance between the positioning terminal and surrounding base stations, and introduces averaging of the signal round-trip time to reduce single-measurement errors. Specifically, the time it takes for the signal to travel from the positioning terminal to the base station is... The time it takes for the image to be reflected back from the base station to the positioning terminal is Then the signal round-trip time The sum of the two is: However, the speed of signal propagation in the air Actual one-way time Introducing calibration factors To compensate for hardware latency and environmental factors: Furthermore, the time difference distance between the positioning terminal and the base station It can be represented as: .

[0021] Furthermore, the distance calculation unit utilizes a signal attenuation compensation algorithm to consider the attenuation effect of the signal during propagation, i.e., the initial strength of the signal at the time of transmission is... The received signal strength is The relationship between the signal attenuation coefficient and distance is as follows: ,in, It is the attenuation constant; solving this equation yields the signal attenuation compensation distance. ,Right now .

[0022] Furthermore, the distance calculation unit calculates the distance between the positioning terminal and surrounding base stations using bidirectional time difference measurement and signal attenuation compensation. and The final distance estimate is formed through weighted fusion, i.e. ,in, It is a weighting factor.

[0023] Furthermore, the positioning algorithm processor receives distance data from multiple base stations from the distance calculation unit. By combining triangulation algorithms, the location coordinates of the base station are transformed into a unified coordinate system, thus calculating the location coordinates of the positioning terminal. System of equations: ,in, These are the location coordinates of the i-th base station. It is the distance from the positioning terminal to the i-th base station, i=1,2,3, which is determined by solving the system of equations. The location coordinates of the positioning terminal are obtained. ,Right now .

[0024] Furthermore, the positioning algorithm processor introduces error correction coefficients, base station weighting factors, and error exponents to correct positioning errors caused by multipath effects and other interference. ,Right now ,in, It is the error correction coefficient. It refers to the number of base stations involved in the positioning process. It is the first Weighting factors for each base station, It is the first Positioning error of each base station It is the error index, which, combined with the positioning results and the error-corrected value, calculates the final position coordinates. ,Right now ,in, and They are exist shaft and The component along the axial direction is used to transmit the calculated position information to the microprocessor of the positioning terminal through the interface circuit.

[0025] Furthermore, the positioning calculation module in the server receives location coordinate information from the positioning terminal. The received location information is matched with a high-precision indoor map, i.e. , These are the matched map points. It is the set of all points in a high-precision indoor map. , (m) represents the coordinates of the m-th point on the map. The initial positioning results are corrected based on map information by dynamically adjusting the correction coefficients. and and weighting factors To adapt to different environmental conditions, that is , Combining the corrected coordinates and positioning error The provided value determines the final location, i.e. , ,in, and These are the positioning errors. exist shaft and The component along the axial direction.

[0026] Furthermore, the system also includes a mobile terminal application, through which indoor personnel can view their location information and evacuation routes, understand their specific location within the building, and communicate with fire and rescue personnel, all displayed in a graphical interface.

[0027] Furthermore, the mobile terminal application has a one-click alarm function. When people indoors encounter an emergency, they can send an alarm message to fire and rescue personnel through the one-click alarm function, and at the same time upload their location information and the situation on site.

[0028] Compared with existing technologies, this indoor positioning system for fire safety evacuation has the following advantages:

[0029] I. The indoor positioning system for fire safety evacuation of the present invention has extremely high positioning accuracy and reliability. The positioning terminal adopts ultra-wideband (UWB) positioning technology, which can accurately determine the location of people in complex indoor environments. The UWB positioning module, through a signal transmitter and receiver, combined with a high-precision distance calculation unit and an advanced positioning algorithm processor, can achieve high-precision location positioning. In emergency situations such as fires, even in the presence of interference factors such as smoke and high temperatures, the system can operate stably, providing accurate personnel location information for fire rescue work, helping rescuers to formulate more effective rescue plans, improve rescue efficiency, and maximize the protection of personnel safety.

[0030] Second, this invention enables intelligent control of fire-fighting equipment. The fire-fighting equipment control module, based on personnel location information provided by the positioning terminal and combined with fire alarm signals, achieves precise control of the fire-fighting equipment. Once the personnel location is determined, the fire linkage controller can dynamically adjust the water spray intensity and smoke exhaust direction of the fire-fighting equipment according to the distribution of personnel, thereby improving the utilization efficiency of the fire-fighting equipment. At the same time, the server's map management module and positioning calculation module, in conjunction with UWB positioning technology, update high-precision indoor maps in real time, providing more accurate environmental information for the control of fire-fighting equipment. This intelligent control function of fire-fighting equipment can better utilize the fire-fighting equipment in emergency situations, improve the effectiveness of fire safety evacuation, and reduce losses caused by fire.

[0031] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a structural diagram of an indoor positioning system for fire safety evacuation.

[0034] Figure 2 This is an operation flowchart for an indoor positioning system used for fire safety evacuation. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] Large shopping malls, with their vast areas, numerous floors, and complex internal structures, include multiple brand stores, dining areas, entertainment facilities, and extensive public spaces. These malls experience high daily foot traffic, especially during holidays and promotional events, when the density of people is extremely high. To ensure the rapid and accurate location of people in emergencies such as fires and to guide their safe evacuation, the shopping mall has introduced the indoor positioning system for fire safety evacuation of this invention to improve the efficiency of personnel safety evacuation in emergency situations.

[0038] In its implementation, the UWB positioning module in the positioning terminal first transmits ultra-wideband signals to surrounding UWB base stations via a signal transmitter. The signal transmitter possesses powerful signal transmission capabilities, enabling effective signal transmission even in complex indoor environments. The signal receiver is constantly ready to receive ultra-wideband signals from surrounding base stations and other positioning terminals; its high sensitivity allows it to accurately capture even weak signals. The distance calculation unit calculates the distance between the positioning terminal and surrounding base stations based on the received signal and its propagation speed, using bidirectional time difference measurement technology and a signal attenuation compensation algorithm. For example, the timestamps of the UWB signals transmitted by the positioning terminal and received from surrounding base stations are precisely recorded using the signal transmitter and receiver. The time it takes for the signal to travel from the positioning terminal to the base station is... Then the signal round-trip time The sum of the two is: The speed of signal propagation in the air Actual one-way time Introducing calibration factors To compensate for hardware latency and environmental factors: Furthermore, the time difference distance between the positioning terminal and the base station It can be represented as: Meanwhile, using a signal attenuation compensation algorithm, the initial signal strength at the time of transmission is considered to be... The received signal strength is The relationship between the signal attenuation coefficient and distance is as follows: ,in, It is the attenuation constant; solving this equation yields the signal attenuation compensation distance. ,Right now The distance is calculated by combining two-way time difference measurement with signal attenuation compensation. and The final distance estimate is formed through weighted fusion, i.e. Through careful adjustments, the most accurate distance estimate can be obtained.

[0039] The positioning algorithm processor receives distance data from multiple base stations from the distance calculation unit. By combining triangulation algorithms to transform the base station's location coordinates into a unified coordinate system, the location coordinates of the positioning terminal are accurately calculated by solving a system of equations. ,Right now ,in, and The result is obtained through calculations using a complex system of equations, that is, To ensure positioning accuracy, the positioning algorithm processor introduces error correction coefficients, base station weighting factors, and error exponents to correct positioning errors caused by multipath effects and other interference. ,Right now ,in, It is the error correction coefficient. It refers to the number of base stations involved in the positioning process. It is the first Weighting factors for each base station, It is the first Positioning error of each base station It is the error index, which, combined with the positioning results and the error-corrected value, calculates the final position coordinates. ,Right now ,in, and They are exist shaft and In the axial direction, the interface circuit stably and quickly transmits the position information calculated by the positioning algorithm processor to the microprocessor of the positioning terminal. After the microprocessor efficiently processes the position information, it sends the position information to the server in real time through the wireless communication module, ensuring that the server can obtain the latest position information of the personnel in a timely manner.

[0040] The server's database stores high-precision indoor maps and personnel location information. The map information is detailed enough to include the location and shape of every shop, passageway, staircase, etc., within the mall. Personnel location information is accurate to the real-time coordinates of each positioning terminal. The map management module is responsible for meticulous management and timely updates of the high-precision indoor maps. Based on the location information from the UWB positioning terminals, it updates the positions of personnel on the map in real time to ensure consistency between the displayed personnel positions and the actual situation. The positioning calculation module receives the location coordinate information from the positioning terminals. The received location information is accurately matched with a high-precision indoor map, i.e. , These are the matched map points. It is the set of all points in a high-precision indoor map. , (m) represents the coordinates of the m-th point on the map. The initial positioning results are corrected based on map information by dynamically adjusting the correction coefficients. and and weighting factors To adapt to different environmental conditions, that is , Combining the corrected coordinates and positioning error The provided value determines the final location, i.e. , ,in, and These are the positioning errors. exist shaft and The fire alarm controller continuously monitors fire alarm signals within the shopping mall. Upon detecting a fire, it immediately receives the alarm signal and rapidly transmits it to the fire linkage controller. Based on real-time location information and the fire alarm signal, the fire linkage controller intelligently controls the operation of fire-fighting equipment. For example, if the system detects people trapped in a certain area during a fire, the fire linkage controller will precisely and intelligently control nearby fire-fighting equipment, such as adjusting the intensity and direction of water spray, to ensure safe evacuation. Simultaneously, it rationally adjusts the operation of the smoke extraction system based on the distribution of people to ensure good air quality in evacuation routes.

[0041] Indoor occupants can conveniently view their location and clear evacuation routes via a mobile application. Within the mall, individuals can access the application at any time to clearly see their exact location and obtain the optimal evacuation route. The evacuation routes are displayed in an intuitive graphical interface, along with text descriptions and voice prompts, ensuring quick understanding and adherence. The application also features real-time communication with fire and rescue personnel. In case of an emergency, individuals can quickly send an alarm to fire and rescue personnel through the application, simultaneously uploading their location information and photos or videos of the scene. This allows rescue personnel to promptly and comprehensively understand the situation and take appropriate rescue measures. The application's simple and intuitive graphical interface makes information more intuitive and easy to understand, facilitating quick access to necessary information. The interface design considers user habits and the psychological needs in emergency situations, ensuring that individuals can quickly find key information and react correctly in tense circumstances.

[0042] In summary, by applying the indoor positioning system for fire safety evacuation of this invention in large shopping malls, it is possible to quickly and accurately determine the location of people in emergency situations such as fires, intelligently control the operation of fire-fighting equipment, improve the efficiency of personnel evacuation, and maximize the protection of personnel's lives.

[0043] Example 2

[0044] This embodiment describes the specific application process of an indoor positioning system for fire safety evacuation in a large hospital to ensure that people can evacuate safely and quickly in case of emergencies.

[0045] In the specific implementation, first, the hospital has a complex building structure, including multiple areas such as outpatient buildings, inpatient buildings, and medical technology buildings. There is a large flow of people, including patients, medical staff, and visitors. At various key positions in the hospital, such as corridors, stairwells, elevator lobbies, and wards, multiple UWB base stations are installed. The installation positions of these base stations are carefully planned to ensure that the signal can cover every corner of the hospital. At the same time, to ensure the stability of the signal, the base stations use high-performance hardware devices and are regularly maintained and detected. A positioning terminal is equipped for each patient, medical staff, and visitor in the hospital. These positioning terminals are designed to be small and easy to wear, and will not affect the normal activities of people. The positioning terminal can be worn on the wrist or hung on the chest, and can collect the position information of people in real time. The server is installed in the central computer room of the hospital, equipped with powerful computing capabilities and storage capacity, and can quickly process a large amount of positioning data and map information. At the same time, the server is also integrated with the hospital's fire protection system, monitoring system, etc. to achieve information sharing and linkage. In daily use, the positioning terminal will collect the position information of people in real time and send this information to the server through the wireless communication module. After receiving the position information, the server will locate the people according to the stored high-precision indoor map and display the position information of the people on the monitoring screen. The hospital management staff can understand the distribution of people in the hospital at any time through the monitoring screen for reasonable scheduling and management.

[0046] In the event of an emergency such as a fire, the indoor positioning system immediately activates emergency mode. The positioning terminal emits an alarm to alert personnel to safety and indicates evacuation directions. Simultaneously, the server sends the personnel's location information to the fire equipment control module. Based on the personnel's location information and the fire alarm signal, the fire equipment control module intelligently controls the operation of fire equipment. For example, when a fire occurs on a certain floor, the fire alarm controller immediately receives the fire alarm signal and sends it to the fire linkage controller. The fire linkage controller determines which areas require priority for fire suppression and evacuation based on the personnel's location information. If a patient is trapped in a ward, the fire linkage controller controls nearby fire equipment, such as sprinkler and smoke extraction systems, to create a relatively safe environment for the patient and guide rescue personnel to the trapped person's location quickly. During evacuation, the positioning terminal provides real-time evacuation route guidance. Personnel can understand their current location and the safe exit they should go to through the display screen or voice prompts on the positioning terminal. Meanwhile, the server will dynamically adjust evacuation routes based on the location information of the personnel to avoid congestion in a certain area. For patients with mobility difficulties, the hospital is equipped with special evacuation equipment. In an emergency, medical staff can quickly find patients with mobility difficulties through positioning terminals and use evacuation equipment to safely transfer them to a safe area.

[0047] In addition, the hospital's mobile terminal application also played an important role. Medical staff and patients can use the application on their mobile phones to check their location information and the surrounding environment at any time. In case of emergency, they can send alarm information to fire and rescue personnel through the application and provide their location information and the situation on site so that fire and rescue personnel can carry out rescue quickly and accurately. Throughout the implementation process, the indoor positioning system is regularly tested and drilled to ensure the stability and reliability of the system.

[0048] In summary, by applying the indoor positioning system for fire safety evacuation of this invention in hospitals, the efficiency of personnel evacuation in emergency situations has been greatly improved, effectively protecting the lives of personnel. Whether in routine management or emergency response, this system has played an important role and provided strong support for the safe operation of hospitals.

[0049] To verify the positioning accuracy of this system in a fire and smoke environment, the applicant conducted multiple sets of comparative experiments to verify the system's superior positioning accuracy. The experimental data are detailed and reproducible, as follows:

[0050] The positioning accuracy of bidirectional time difference measurement, signal attenuation compensation, and dynamic weighted fusion of smoke concentration was verified and compared with existing single TOF algorithm and conventional fixed weight fusion algorithm under different smoke concentration environments, combined with the positioning error correction model.

[0051] Experimental environment parameters: The experimental space is a 10m×10m×3m enclosed simulated room (simulating indoor scenes such as shopping malls and hospitals), with 3 UWB base stations set up (coordinates (0,0), (10,0), (5,10) respectively). The positioning terminal is worn by the experimenter and can be moved to any test point in the room.

[0052] Smoke Simulation Device: A professional smoke generator that can precisely adjust the smoke concentration (0-2.5mg / m³). The smoke type is fire-fighting simulated smoke (the composition is consistent with real fire smoke, non-conductive and non-corrosive).

[0053] Environmental monitoring equipment: smoke concentration detector (accuracy: ±0.01mg / m³), temperature sensor (accuracy: ±0.1℃), humidity sensor (accuracy: ±1%RH). During the experiment, the temperature was controlled at 25±2℃ and the humidity at 50±5%RH to eliminate interference from temperature and humidity on the signal.

[0054] Positioning accuracy verification tool: Laser rangefinder (accuracy: ±0.01m), used to calibrate the actual position coordinates of the positioning terminal as a benchmark for error calculation.

[0055] Test equipment: the positioning terminal of this application, a conventional UWB positioning terminal (supporting only a single TOF algorithm), and a conventional fusion positioning terminal (supporting the TOF+RSS fixed weight fusion algorithm, with a fixed weight ω=0.5).

[0056] Test point setup: Nine test points were evenly selected in the experimental space (coordinates (2,2), (2,5), (2,8), (5,2), (5,5), (5,8), (8,2), (8,5), (8,8) respectively). Each test point was tested three times, and the average value was taken as the localization result of the test point.

[0057] Smoke concentration gradient: Three environmental conditions were set: no smoke (0mg / m³), low smoke concentration (1.0mg / m³), and high smoke concentration (2.0mg / m³), simulating normal environment, initial fire environment, and severe fire environment, respectively.

[0058] Comparison Algorithms:

[0059] Comparison Group 1: Single TOF algorithm, existing conventional technology, without attenuation compensation and dynamic weighting;

[0060] Comparison Group 2: Conventional fixed-weight fusion algorithm, TOF+RSS, fixed weight ω=0.5, no dynamic adjustment of smoke concentration;

[0061] Experimental group: In the first embodiment of the present invention, the positioning error correction model and ω are dynamically adjusted according to the smoke concentration.

[0062] Error calculation method: Positioning error = √[(X-coordinates calculated by positioning terminal - actual coordinates determined by laser calibration)] )²+(Y-coordinates calculated by the positioning terminal - actual coordinates determined by laser calibration) )²], which is the planar distance error.

[0063] (1) Experimental data in a smoke-free environment (0 mg / m³)

[0064]

[0065] In a smoke-free environment, the average positioning error of the proposed solution is 0.29m, which is 63.75% lower than that of comparison group 1 (0.80m) and 43.14% lower than that of comparison group 2 (0.51m), demonstrating the fundamental optimization effect of the core algorithm on ranging accuracy.

[0066] (2) Experimental data in low smoke concentration environment (1.0 mg / m³)

[0067]

[0068] In low smoke concentration environments, the delay and attenuation effects of smoke on signals become apparent, and the positioning errors of both control group 1 and control group 2 increase significantly (by 42.5% and 109.8% respectively compared to the smoke-free environment). However, the solution of this invention, by dynamically adjusting the weighting factor ω (at this time ω=0.3, focusing on signal attenuation compensation), achieves an average positioning error of only 0.40m, which is 64.91% lower than that of control group 1 (1.14m) and 62.62% lower than that of control group 2 (1.07m), demonstrating the anti-interference advantage of the dynamic smoke concentration adaptation mechanism.

[0069] (3) Experimental data in high smoke concentration environment (2.0 mg / m³)

[0070]

[0071] In environments with high smoke concentrations, signal propagation is severely interfered with, and the positioning errors of comparison groups 1 and 2 increase dramatically (by 120% and 235.3% respectively compared to smoke-free environments), failing to meet the positioning accuracy required for fire safety evacuation (typically requiring an error ≤1m). However, the solution proposed in this application compensates for signal delay caused by smoke by using a calibration factor α, and corrects the intensity attenuation error by combining a signal attenuation compensation algorithm. At the same time, the weighting factor ω is adjusted to 0.1 (maximizing the signal attenuation compensation weight), resulting in an average positioning error of only 0.50m, which remains within the high accuracy range. Compared to comparison group 1 (1.76m), the error is reduced by 71.59%, and compared to comparison group 2 (1.71m), the error is reduced by 70.76%, fully demonstrating the stability and superiority of the core algorithm of this application in extreme fire environments.

[0072] Through comparative experiments in three environments with different smoke concentrations, the following conclusions can be drawn:

[0073] The positioning accuracy of this invention is significantly better than that of existing conventional technologies (single TOF algorithm, fixed weight fusion algorithm) in all experimental environments, with a reduction in positioning error of more than 40%, and a reduction in error of more than 70% in high smoke concentration environments, which fully meets the stringent requirements for positioning accuracy in fire safety evacuation.

[0074] The calibration factor α compensation, attenuation constant β quantization, and smoke concentration dynamic weighting factor ω of the present invention work synergistically to effectively resist signal delay, attenuation, and interference in fire environments. In contrast, conventional technologies, due to a lack of targeted optimization design, suffer a sharp decline in positioning accuracy in smoke environments.

[0075] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An indoor positioning system for fire safety evacuation, characterized in that, The indoor positioning system comprises a positioning terminal, a wireless communication module, a server and a fire-fighting equipment control module, the positioning terminal is worn on the body of an indoor person, is used for collecting position information of the person in real time, and sends the position information to the server through the wireless communication module, the server receives the position information, and positions the person according to the stored high-precision indoor map, meanwhile, the server also sends the position information of the person to the fire-fighting equipment control module, so that the fire-fighting equipment control module controls the operation of the fire-fighting equipment according to the position information of the person; The positioning terminal is worn on the body of an indoor person and adopts an ultra-wideband (UWB) positioning technology, accurately determines the specific position of the person in the indoor, and specifically comprises a microprocessor, a UWB positioning module and a power module, the UWB positioning module comprises a signal transmitter, a signal receiver, a distance calculation unit, a positioning algorithm processor, a synchronization and calibration unit and an interface circuit, can be used for measuring the distance between the person and surrounding base stations, and determining the position of the person through a triangular positioning algorithm, the microprocessor processes the position information, and sends the position information to the server through the wireless communication module, and the power module provides power supply for the positioning terminal; The distance calculation unit calculates the distance between the positioning terminal and the surrounding base stations using the two-way time difference measurement technique by recording the timestamps of the signals using the signal transmitter and signal receiver for the UWB signals transmitted by the positioning terminal and received from the surrounding base stations, and introducing averaging processing of the signal round trip time to reduce the single measurement error, i.e. the time for the signal to be transmitted from the positioning terminal to the base station is , and the time for the signal to be reflected from the base station back to the positioning terminal is , then the signal round trip time is the sum of the two, i.e. , but the propagation speed of the signal in the air is , the actual one-way time is , a calibration factor is introduced to compensate for the hardware delay and environmental factors: , and further, the time difference distance between the positioning terminal and the base station can be expressed as: ;​ The distance calculation unit considers the attenuation effect of the signal in the propagation process by using a signal attenuation compensation algorithm, that is, the initial intensity when the signal is transmitted is , the received signal intensity is , the relationship between the signal attenuation coefficient and the distance is: , wherein, is the attenuation constant, and the signal attenuation compensation distance is obtained by solving the equation, that is, ; The distance calculation unit calculates the distance between the positioning terminal and the surrounding base stations by compensating the bi-directional time difference measurement with signal attenuation and The final distance estimation is formed by weighted fusion, that is wherein, is the weighted factor; The wireless communication module is responsible for establishing a data transmission channel between the positioning terminal and the server; The server comprises a database, a map management module and a positioning calculation module, the database is used for storing high-precision indoor maps and position information of the person, the map management module is responsible for managing and updating the high-precision indoor maps, and the positioning calculation module calculates the position of the person according to the position information sent by the positioning terminal and the high-precision indoor maps, and determines the specific position of the person in the indoor; The fire-fighting equipment control module comprises a fire alarm controller, a fire-fighting linkage controller and fire-fighting equipment, the fire alarm controller is used for receiving a fire alarm signal, and sending the alarm signal to the fire-fighting linkage controller, the fire-fighting linkage controller controls the operation of the fire-fighting equipment according to the position information of the person and the fire alarm signal; The map management module and the positioning calculation module of the server can cooperate with the ultra-wideband positioning technology, namely, the map management module updates the high-precision indoor maps in real time according to the position information of the UWB positioning terminal, and the positioning calculation module quickly and accurately calculates the position of the person by using the UWB positioning technology; The fire-fighting equipment control module can intelligently control the operation of the fire-fighting equipment according to the position information of the person provided by the ultra-wideband positioning technology.

2. A fire safety evacuation indoor positioning system according to claim 1, characterized in that, In the UWB positioning module in the positioning terminal: The signal transmitter is used for emitting an ultra-wideband signal for effective positioning in a complex indoor environment; The signal receiver is used for receiving ultra-wideband signals from surrounding base stations and other positioning terminals; The distance calculation unit calculates the distance between the positioning terminal and surrounding base stations by using a time difference measurement principle according to signals received by the signal receiver and a signal propagation speed; The positioning algorithm processor receives distance data output by the distance calculation unit, combines a triangular positioning algorithm, and calculates specific position coordinates of the positioning terminal in the indoor; The synchronization and calibration unit is used for ensuring time synchronization between the positioning terminal and surrounding base stations, and performing system calibration. The interface circuit is used for transmitting the position information calculated by the positioning algorithm processor to a microprocessor of the positioning terminal.

3. A fire safety evacuation indoor positioning system according to claim 1, characterized in that, The positioning algorithm processor receives the plurality of base station distance data from the distance calculation unit , converts the position coordinates of the base stations into a unified coordinate system in combination with a triangular positioning algorithm, i.e. calculates the position coordinates of the positioning terminal Equation set: , wherein is the position coordinates of the i-th base station, is the distance from the positioning terminal to the i-th base station, i = 1, 2, 3, the position coordinates of the positioning terminal are obtained by solving the equation set , i.e. .​ 4. A fire safety evacuation indoor positioning system according to claim 3, characterized in that, The positioning algorithm processor introduces error correction coefficient, base station weight factor and error index, which are used to correct the positioning error caused by multipath effect and other interference i.e. wherein, is error correction coefficient, is the number of base stations participating in positioning, is the weight factor of the th base station, is the positioning error of the th base station, is error index, combined with the positioning result and the value after error correction, the final position coordinates are calculated i.e. wherein, and are respectively the components in the direction of axis and axis direction, the calculated position information is transmitted to the microprocessor of the positioning terminal through the interface circuit.

5. A fire safety evacuation indoor positioning system according to claim 1, wherein, The positioning calculation module in the server receives location coordinate information from the positioning terminal. The received location information is matched with a high-precision indoor map, i.e. , These are the matched map points. It is the set of all points in a high-precision indoor map. , (m) represents the coordinates of the m-th point on the map. The initial positioning results are corrected based on map information by dynamically adjusting the correction coefficients. and and weighting factors To adapt to different environmental conditions, that is , Combining the corrected coordinates and positioning error The provided value determines the final location, i.e. , ,in, and These are the positioning errors. exist shaft and The component along the axial direction.

6. A fire safety evacuation indoor positioning system according to claim 1, wherein, The system further comprises a mobile terminal application program, through which the indoor personnel can view their own position information and evacuation routes, understand their specific positions in the building and communicate with the fire rescue personnel, and the information is displayed in a graphical interface.

7. A fire safety evacuation indoor positioning system according to claim 6, characterised in that, The mobile terminal application program has a one-key alarm function, through which the indoor personnel can send alarm information to the fire rescue personnel and upload their own position information and the on-site situation when encountering an emergency.

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