Indoor positioning system and method

Abstract

The invention discloses an indoor positioning system and method, and relates to the technical field of indoor positioning. The indoor positioning system comprises at least one first optical module, at least two second optical modules, at least two control modules and a position calculation module. The first optical module is used for emitting a first optical signal. The second optical module is used for receiving the first optical signal, analyzing the first optical signal to obtain an analyzed first optical signal, and sending the analyzed first optical signal to the control module. The control module is used for receiving the analyzed first optical signal from the second optical module and transmitting the analyzed first optical signal to the position calculation module. The position calculation module is used for receiving the analyzed first optical signals from the at least two control modules and determining the position of the first optical module according to the analyzed first optical signals and a triangulation positioning algorithm. The system uses the visible light communication technology, is not influenced by external electromagnetic interference, ensures the accuracy and stability of positioning, is low in cost, and can be widely applied.

Description

Technical Field

[0001] This invention relates to the field of indoor positioning technology, and more particularly to an indoor positioning system and method. Background Technology

[0002] Signal propagation indoors is subject to more interference and obstacles. Due to the presence of various electromagnetic interference sources in the indoor environment, such as wireless networks, electronic devices, and other communication systems, these interferences may negatively affect the accuracy and reliability of the positioning system. Summary of the Invention

[0003] The technical problem to be solved by this invention is that various electromagnetic interference sources exist in the indoor environment, which may have a negative impact on the accuracy and reliability of the positioning system.

[0004] To address the aforementioned shortcomings of existing technologies, the following solutions are provided:

[0005] In a first aspect, the present invention provides an indoor positioning system, comprising at least one first optical module, at least two second optical modules, at least two control modules, and a position calculation module. The first optical module is used to emit a first optical signal. The second optical modules are used to receive the first optical signal, parse the first optical signal to obtain a parsed first optical signal, and send the parsed first optical signal to the control modules. The control modules are used to receive the parsed first optical signal from the second optical modules and transmit the parsed first optical signal to the position calculation module. The position calculation module is used to receive the parsed first optical signal from at least two control modules and determine the position of the first optical module based on the parsed optical signal and a triangulation algorithm.

[0006] Optionally, the second optical module is further configured to send a second optical signal to the first optical module, and the first optical module is further configured to, upon receiving the second optical signal, emit a third optical signal based on the second optical signal, the third optical signal being used to determine the position of the first optical module. The third optical signal has a different frequency than the first optical signal.

[0007] Optionally, the first optical module includes a power supply, a microcontroller unit (MCU), a light-emitting diode (LED), and a photosensitive element. The power supply powers the MCU, LED, and photosensitive element. The photosensitive element receives a second optical signal, converts it into an electrical signal, and sends the electrical signal to the MCU. The MCU receives the electrical signal, generates a corresponding control signal based on the electrical signal, and sends the control signal to the LED. The control signal controls the blinking frequency of the LED. The LED receives the control signal and blinks according to the control signal.

[0008] Optionally, the first optical module is set in the employee's ID card or asset tag.

[0009] Optionally, the second optical module and the control module are one-to-one, and the second optical module and the control module corresponding to the second optical module are arranged in the indoor lamps according to a preset arrangement rule, and the range of light signals received by all the second optical modules in at least two second optical modules includes all areas of the indoor space.

[0010] Optionally, the indoor positioning system further includes an inertial measurement module, which corresponds one-to-one with the first optical module. The inertial measurement module is used to measure the three-dimensional angular velocity data and acceleration data of the first optical module, and transmits the three-dimensional angular velocity data and acceleration data of the first optical module to the position calculation module. The position calculation module is also used to determine the position of the first optical module based on the parsed first optical signal, the three-dimensional angular velocity data and acceleration data of the first optical module.

[0011] Optionally, the indoor positioning system also includes an environmental sensing module, which is used to acquire indoor ambient temperature data and indoor ambient humidity data in real time, and send the indoor ambient temperature data and indoor ambient humidity data to the location calculation module. The location calculation module is also used to determine the position of the first optical module based on the parsed first optical signal, indoor ambient temperature data and indoor ambient humidity data.

[0012] Optionally, the indoor positioning system also includes an alarm module, which periodically acquires the position and working status of the first optical module and issues an alarm message when the position or working status of the first optical module is abnormal.

[0013] Optionally, the position calculation module is used to preprocess the parsed first optical signal to obtain preprocessed data, and then extract features from the preprocessed data. The position of the first optical module is determined based on the feature-extracted data and a triangulation algorithm.

[0014] Optionally, the position calculation module is also used to acquire the three-dimensional angular velocity data of the first optical module, the acceleration data of the first optical module, the indoor ambient temperature data, and the indoor ambient humidity data. The feature-extracted data, the three-dimensional angular velocity data of the first optical module, the acceleration data of the first optical module, the indoor ambient temperature data, and the indoor ambient humidity data are fused using a data fusion algorithm, and the position of the first optical module is determined based on the fused data and a triangulation algorithm.

[0015] Optionally, the indoor positioning system also includes a wireless communication module, which is used to establish additional wireless transmission channels for the first optical module, the second optical module, the control module, and the location calculation module.

[0016] Secondly, the present invention provides an indoor positioning method applied to the aforementioned indoor positioning system. The method includes: a first optical module emitting a first optical signal; a second optical module receiving the first optical signal, parsing the first optical signal to obtain a parsed first optical signal, and sending the parsed first optical signal to a control module; the control module receiving the parsed first optical signal from the first optical module and transmitting the parsed first optical signal to a position calculation module; and the position calculation module receiving the parsed first optical signals from at least two control modules and determining the position of the first optical module based on the parsed optical signals and a triangulation algorithm.

[0017] The indoor positioning system and method provided by this invention employ low-light communication and visible light positioning technologies to achieve rapid positioning, unaffected by external electromagnetic interference, ensuring positioning accuracy and stability. The overall cost is low, and it can be widely applied. The indoor positioning system provided by this invention, through auxiliary means such as data fusion algorithms, inertial measurement modules, and environmental perception modules, can provide high-precision and high-reliability indoor positioning. The indoor positioning system provided by this invention is equipped with an alarm module to monitor the safety status of employees and assets in real time, effectively improving security. Attached Figure Description

[0018] Figure 1 This is a structural diagram of an indoor positioning system according to an embodiment of the present invention;

[0019] Figure 2 This is a structural diagram of a first optical module in an embodiment of the present invention;

[0020] Figure 3 This is a structural diagram of another indoor positioning system according to an embodiment of the present invention;

[0021] Figure 4 This is a structural diagram of another indoor positioning system according to an embodiment of the present invention;

[0022] Figure 5 This is a structural diagram of another indoor positioning system according to an embodiment of the present invention;

[0023] Figure 6 This is a flowchart illustrating a method for a position calculation module to determine the position of a first optical module in an embodiment of the present invention;

[0024] Figure 7 This is a flowchart illustrating another method for a position calculation module to determine the position of a first optical module in an embodiment of the present invention;

[0025] Figure 8 This is a structural diagram of another indoor positioning system according to an embodiment of the present invention;

[0026] Figure 9This is a flowchart of an indoor positioning method as an example of an embodiment of the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solution of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] It is understood that the specific embodiments and accompanying drawings described herein are merely for explaining the invention and are not intended to limit the invention.

[0029] It is understood that, without conflict, the various embodiments and features in the embodiments of the present invention can be combined with each other.

[0030] It is understood that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, while the parts unrelated to the present invention are not shown in the drawings.

[0031] It is understood that each unit or module involved in the embodiments of the present invention may correspond to only one entity structure, or may be composed of multiple entity structures, or multiple units or modules may be integrated into one entity structure.

[0032] It is understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of this invention may occur in a different order than that marked in the accompanying drawings.

[0033] It is understood that the flowcharts and block diagrams of this invention illustrate the possible architecture, functions, and operations of systems, apparatuses, devices, and methods according to various embodiments of this invention. Each block in the flowchart or block diagram may represent a unit, module, program segment, or code, containing executable instructions for implementing the specified function. Furthermore, each block or combination of blocks in the block diagram and flowchart can be implemented using a hardware-based system to achieve the specified function, or using a combination of hardware and computer instructions.

[0034] It is understood that the units and modules involved in the embodiments of the present invention can be implemented by software or by hardware. For example, the units and modules can be located in a processor.

[0035] Embodiments of the present invention provide an indoor positioning system, such as Figure 1As shown, the indoor positioning system 10 includes at least one first optical module 11, at least two second optical modules 12, at least two control modules 13, and a position calculation module 14. The first optical module 11 emits a first optical signal. The second optical modules 12 receive the first optical signal, parse it to obtain a parsed first optical signal, and send the parsed first optical signal to the control modules 13. The control modules 13 receive the parsed first optical signal from the second optical modules and transmit it to the position calculation module 14. The position calculation module 14 receives the parsed first optical signal from the at least two control modules 13 and determines the position of the first optical module 11 based on the parsed first optical signal from the at least two control modules 13 and a triangulation algorithm.

[0036] Understandably, in visible light communication protocols, the frequency of the light signal and the duration of light illumination represent different meanings, thus enabling information transmission via light signals. The first optical module 11 and the second optical module 12 can communicate according to the visible light communication protocol. However, the on / off state of everyday lights does not conform to the visible light communication protocol; therefore, even if the second optical module 12 receives a light signal from an everyday light source, it will not process it.

[0037] Understandably, to distinguish between the various first optical modules 11 within at least one first optical module, the frequencies of the first optical signals emitted by each first optical module 11 can be different. For example, each first optical module 11 can be assigned a number and stored in the system for easy reference by staff. The number corresponds one-to-one with the first optical module 11, meaning the number can correspond one-to-one with the frequency of the first optical signal emitted by the first optical module 11. Thus, when the second optical module 12 receives a first optical signal, it can determine which first optical module 11 emitted the first optical signal based on its frequency.

[0038] Understandably, the position of each of the at least two second optical modules 12 can be fixed and known in advance. That is, if two or more second optical modules 12 capture the same first optical signal emitted by the first optical module 11 when the first optical module 11 moves, the position calculation module 14 can determine the position of the first optical module 11 according to the triangulation algorithm.

[0039] Understandably, the number of each first optical module 11 in at least one first optical module and the number of each second optical module 12 in at least two second optical modules are not necessarily the same. Wireless communication is possible between each first optical module 11 in at least one first optical module and each second optical module 12 in at least two second optical modules. Wireless communication is also possible between each control module 13 in at least two control modules and the location calculation module 14. The location calculation module 14 can be located in a relevant management system (such as a park management system).

[0040] Understandably, each of the first optical modules 11 in at least one first optical module can be set in a different room, and each of the second optical modules 12 in at least two second optical modules can also be set in a different room. Since the communication range of visible light communication is limited, each second optical module 12 in a room may only receive the optical signal emitted by the first optical module 11 in that room. Each of the at least two control modules 13 is set in correspondence with each of the second optical modules 12 in at least two second optical modules, and the second optical module 12 can communicate with the corresponding control module 13 via wired connection, that is, the two can have an electrical connection.

[0041] In some embodiments, the second optical module 12 is further configured to send a second optical signal to the first optical module 11, and the first optical module 11 is further configured to, upon receiving the second optical signal, emit a third optical signal based on the second optical signal, the third optical signal being used to determine the position of the first optical module 11. The third optical signal has a different frequency than the first optical signal.

[0042] Understandably, in some cases, it is necessary to adjust the frequency of the first optical signal emitted by the first optical module 11 (for example, to adjust the number of the first optical module 11). The second optical module 12 can be controlled to emit a second optical signal, and the first optical module 11 can be emitted a third optical signal by adjusting the frequency of the first optical module 11 by the above method.

[0043] Understandably, the only difference between the third optical signal and the first optical signal is the frequency. The principle of using the third optical signal to determine the position of the first optical module 11 is similar to that of the first optical signal. That is, if two or more second optical modules 12 capture the same third optical signal emitted by the first optical module 11 when the first optical module 11 moves, the position calculation module 14 can determine the position of the first optical module 11 according to the triangulation algorithm.

[0044] In some embodiments, such as Figure 2As shown, the first optical module 11 includes a power supply 111, an MCU 112, an LED 113, and a photosensitive element 114. The power supply provides power to the MCU 112, LED 113, and photosensitive element 114. The photosensitive element 114 receives a second optical signal, converts it into an electrical signal, and sends the electrical signal to the MCU 112. The MCU 112 receives the electrical signal, generates a corresponding control signal based on the electrical signal, and sends the control signal to the LED 113. The control signal controls the blinking frequency of the LED 113. The LED 113 receives the control signal and blinks according to the control signal.

[0045] Understandably, the photosensitive element 114 can sense the second light signal from the second light module 12 and convert the second light signal into an electrical signal. The MCU 112 can convert the electrical signal into a control signal. After receiving the control signal, the LED 113 blinks according to the control signal (at this time, the blinking frequency of the LED 113 is no longer the frequency of the first light signal, but the frequency of the third light signal). In this way, the signal emitted by the first light module 11 changes from the first light signal to the third light signal.

[0046] In some embodiments, the first optical module 11 is disposed in an employee ID card or asset tag.

[0047] Understandably, asset tags can be affixed to different assets, and employee ID cards serve as employee credentials. By setting the first optical module 11 in the employee ID card or asset tag, the location of the employee or asset can be achieved.

[0048] In some embodiments, the second optical module 12 and the control module 13 correspond one-to-one, and the second optical module 12 and the control module 13 corresponding to the second optical module 12 are arranged in the indoor lamps according to a preset arrangement rule, and the range of light signals received by all the second optical modules 12 in at least two second optical modules includes all areas of the indoor space.

[0049] Understandably, the range of light received by a single second optical module 12 is limited. If the indoor area of ​​a room is larger than the range of light received by a single second optical module 12, then multiple second optical modules can be installed in the room. The range of light received by all the second optical modules 12 in the room can then cover the entire indoor area.

[0050] Understandably, the structure of the second optical module 12 can be similar to that of the first optical module 11. For example, the second optical module 12 may also include an MCU, a photosensitive element, an LED, and a power supply module. The photosensitive element of the second optical module 12 can receive the first optical signal and can also emit a second optical signal by flashing the LED.

[0051] For example, when there are many indoor lighting devices arranged in a relatively regular manner (e.g., meeting a preset arrangement rule), the indoor lighting devices can be used as LEDs in the second light module 12. A network module, MCU, photosensitive components, and a power supply module can be installed in the lighting devices to form the second light module 12. A control module 13 can then be installed in the indoor lighting devices to complete the setup of the second light module 12 and the control module 13. In this way, the position of each lighting device is determined by a point, and since the lighting devices inside the building have positioning functions, when employees wearing name tags move around indoors, the light emitted by the name tags is recognized by the lighting devices. The lighting devices will determine the distance based on the duration of the data sent by the name tags. If the light is captured by two or more lighting devices simultaneously, the position calculation module 14 can calculate the specific position of the person using triangulation.

[0052] For example, if the indoor lighting fixtures do not conform to the preset arrangement rules, a second light module 12 and a control module 13 can be set at each point according to the preset arrangement rules.

[0053] In some embodiments, such as Figure 3 As shown, the indoor positioning system 10 also includes an inertial measurement module 15, which corresponds one-to-one with the first optical module 11. The inertial measurement module 15 is used to measure the three-dimensional angular velocity data and acceleration data of the first optical module 11, and transmits the three-dimensional angular velocity data and acceleration data of the first optical module 11 to the position calculation module 14. The position calculation module 14 is also used to determine the position of the first optical module based on the parsed first optical signal, the three-dimensional angular velocity data and the acceleration data of the first optical module 11.

[0054] For example, the inertial measurement module 15 may include a gyroscope and an accelerometer, which can measure the three-dimensional angular velocity and acceleration of an object in real time. The inertial measurement module 15 may be installed together with the first optical module 11 in an employee ID card or asset tag to monitor the movement trajectory of employees or the movement of assets in real time.

[0055] In some embodiments, such as Figure 4 As shown, the indoor positioning system 10 also includes an environmental sensing module 16. The environmental sensing module 16 is used to acquire indoor ambient temperature data and indoor ambient humidity data in real time, and send the indoor ambient temperature data and indoor ambient humidity data to the location calculation module 14. The location calculation module 14 is also used to determine the position of the first optical module based on the first optical signal, the indoor ambient temperature data, and the indoor ambient humidity data.

[0056] For example, the environmental sensing module 16 may include a humidity sensor and a temperature sensor.

[0057] Understandably, in indoor environments, factors such as temperature and humidity can affect the propagation characteristics of wireless signals. Different environmental conditions (such as varying temperatures and humidity levels) can cause changes in signal propagation characteristics. By monitoring these environmental parameters in real time, signal attenuation or multipath effects can be more accurately predicted and corrected, thereby improving positioning accuracy. By fusing data from different sensors, a more comprehensive environmental model can be constructed. This multi-source data fusion provides positioning algorithms with more information, enabling a better understanding and description of environmental characteristics. Furthermore, real-time environmental monitoring allows positioning algorithms to dynamically adjust. For example, when a change in humidity is detected, the algorithm can consider possible signal variations and select appropriate filtering or correction measures to ensure the stability and accuracy of positioning. Real-time monitoring of indoor environmental parameters helps improve the adaptability, accuracy, and robustness of positioning algorithms, thereby optimizing overall positioning performance.

[0058] In some embodiments, such as Figure 5 As shown, the indoor positioning system 10 also includes an alarm module 17, which is used to periodically acquire the position and working status of the first optical module 11, and issue an alarm message when the position of the first optical module 11 is abnormal or the working status of the first optical module 11 is abnormal.

[0059] For example, if the first optical module 11 is originally located in room 1 as a non-movable asset (e.g., a computer or printer), and the second optical module 12 in room 2 receives the light signal emitted by the first optical module 11, then the location calculation module knows that the first optical module 11 is located in room 2. In other words, the non-movable asset originally located in room 1 has moved to room 2, which constitutes an abnormal position of the first optical module 11. Conversely, if neither the second optical module 12 in room 1 nor the second optical module 12 in room 2 receives the light signal emitted by the first optical module 11, the location calculation module 14 cannot determine the position of the first optical module 11, and therefore cannot determine the position of the non-movable asset. This is a case where the first optical module 11 is in an abnormal working state.

[0060] For example, in some special industries, considering personnel safety reasons, the relevant management system can set areas where employees are prohibited from entering (such as dangerous areas). When an employee or asset enters the preset dangerous area, the alarm module 17 can accurately trigger an alarm based on the first light signal sent by the first light module 11 and inform the management personnel of the location of the first light module 11. The relevant management system can also dynamically adjust the size and location of the alarm area to adapt to the needs of different scenarios and improve the accuracy and practicality of the alarm.

[0061] For example, the alarm module 17 can also cooperate with the inertial measurement module 15 and the environmental perception module 16. The inertial measurement module 15 can monitor the movement trajectory and status of employees or assets in real time. The alarm module 17 can combine this data to more accurately determine whether there are any safety hazards and trigger corresponding alarms. The alarm module 17 can also use the temperature, humidity and other data provided by the environmental perception module 16 to determine whether the environment poses a threat to the safety of employees or assets. For example, excessively high temperature or excessive humidity may cause certain equipment malfunctions, thereby issuing an alarm in advance.

[0062] In some embodiments, such as Figure 6 As shown, the location calculation module 14 is used to perform steps 601 to 603.

[0063] Step 601: Preprocess the parsed data to obtain preprocessed data.

[0064] Understandably, preprocessing includes cleaning and format normalization of the data to remove outliers and large amounts of duplicate data, thereby reducing the amount of computation required later and lowering the load on the server. Format normalization ensures that the data is on the same scale; for example, it can be achieved by scaling based on the mean and standard deviation of the data.

[0065] Step 602: Extract features from the preprocessed data.

[0066] For example, feature extraction can be performed on the preprocessed data to extract features such as edges, corners, and textures.

[0067] Understandably, raw data typically contains a large amount of information, some of which may be redundant or irrelevant. Feature extraction helps compress data, removing noise and unnecessary interference, allowing the algorithm to focus more on positioning-related signals and retain the most important features, thereby reducing computational complexity and storage requirements. Furthermore, feature extraction can transform high-dimensional data into low-dimensional data, simplifying subsequent calculations. For triangulation algorithms, processing fewer features can speed up computation and reduce resource consumption.

[0068] Step 603: Determine the position of the first optical module based on the data after feature extraction and the triangulation algorithm.

[0069] Understandably, the triangulation algorithm can be implemented as follows:

[0070] After feature extraction, the process of determining the location using triangulation can be divided into the following steps:

[0071] 1. Identify Known Points: In triangulation, at least three known points (reference points) must first be identified, whose coordinates are known. Typically, these points are the locations of other optical modules or fixed base stations.

[0072] 2. Measuring Distance or Angle: The distance or angle from the optical module to be located to a known point needs to be measured. This can be achieved through signal strength, time delay, or other measurement methods. For example, a signal strength attenuation model can be used to estimate the distance, or an angle measuring device can be used to obtain the angle relative to the known point.

[0073] 3. Establish the equation: Based on the known coordinates of the point and the measured distance or angle, establish the equation. For the known point (x... i y i ) and the measured distance d i An equation can be established:

[0074] (xx i ) 2 +(yy i ) 2 =d i 2

[0075] Here (x, y) are the coordinates of the first optical module 11 to be located.

[0076] 4. Solving the equations: By solving the above system of equations, the coordinates of the optical module to be located can be obtained. Numerical methods (such as the least squares method) are typically used to solve these equations. If there are three known points, a unique solution can usually be obtained; if there are more known points, a weighted average can be used to improve the positioning accuracy.

[0077] 5. Verification and Optimization: After obtaining the preliminary positioning results, the accuracy of the positioning can be verified by comparing them with other measurement results. If the positioning results are not ideal, filtering algorithms (such as Kalman filtering) can be considered to optimize the position estimation.

[0078] Through the above steps, the data after feature extraction can be effectively combined with the triangulation algorithm to accurately determine the location of the optical module.

[0079] In some embodiments, such as Figure 7 As shown, the location calculation module 14 is also used to perform steps 701 to 703.

[0080] Step 701: Obtain the three-dimensional angular velocity data of the first optical module, the acceleration data of the first optical module, the indoor ambient temperature data, and the indoor ambient humidity data.

[0081] Understandably, the three-dimensional angular velocity data and acceleration data of the first optical module 11 can be provided by the inertial measurement module 15. The indoor ambient temperature data and indoor ambient humidity data can be provided by the environmental sensing module 16.

[0082] Step 702: According to the preset data fusion algorithm, the data after feature extraction, the three-dimensional angular velocity data of the first optical module, the acceleration data of the first optical module, the indoor ambient temperature data, and the indoor ambient humidity data are fused together.

[0083] For example, when dealing with uncertain and ambiguous information, Dempster-Shafer Theory can be used to construct confidence and likelihood functions, and Dempster's combination rule can be used to fuse evidence from different sources to arrive at more reliable conclusions. The confidence function represents the credibility of a hypothesis or event, assessing the probability of an event occurring based on existing evidence. The likelihood function represents the probability of an event occurring under given conditions and is typically associated with observational data. Evidence fusion refers to integrating information from different sources to obtain more accurate and reliable results. In fields such as localization and decision support, evidence fusion can improve the robustness and accuracy of a system.

[0084] For example, the pre-defined data fusion algorithm could be a method that uses Dempster evidence theory to construct confidence and likelihood functions, and then fuses evidence from different sources using Dempster's combination rule, as follows:

[0085] 1. First, define a problem framework X based on the requirements of this case. The problem includes all possible situations of the target's position and motion state.

[0086] 2. For each device i, obtain a basic probability assignment BPA. The BPA distributes the probability across a subset A of X. For device i, calculate its BPA mi, which represents the confidence level in subset A.

[0087] 3. Use Dempster's combination rules to combine BPAs from different sensors. The combination rule is: m(A) = ∑ B∩C＝A m1(B)×m2(C), where m1 and m2 are the BPAs of the two sensors, A is a subset of X, and B and C are subsets that make B∩C=A.

[0088] 4. Calculate the trust function Bel and the likelihood function PI. The trust function represents the degree of trust in subset A. The calculation formula is as follows: The likelihood function represents the probability of a subset A occurring, and is calculated using the following formula: in It is the complement of A.

[0089] 5. Based on the results of the trust function and the likelihood function, make decisions and select the subset with the highest trust level as the basis for decision-making.

[0090] Step 703: Determine the position of the first optical module based on the data after data fusion and the triangulation algorithm.

[0091] Understandably, the triangulation algorithm can be referred to in the relevant description of step 603, and will not be repeated here.

[0092] In some embodiments, such as Figure 8 As shown, the indoor positioning system 10 may further include a wireless communication module 18, which is used to establish additional wireless transmission channels for the first optical module 11, the second optical module 12, the control module 13, and the location calculation module 14. For example, in the event of a communication failure in the first optical module 11, the second optical module 12, or the control module 13, the wireless communication module 18 can provide additional communication channels to ensure the normal operation of the indoor positioning system 10.

[0093] The structure and working principle of the indoor positioning system 10 provided in the embodiments of the present invention will be illustrated by a specific example below.

[0094] In this example, the indoor positioning system is also known as an interference-free indoor rapid positioning system. This system includes a low-light communication module, a visible light positioning module, an enhancement module, and a security and alarm module (i.e., an alarm module). The low-light communication module provides real-time, reliable communication to help managers effectively track and manage assets and equipment. The visible light positioning module provides accurate indoor positioning for managers, unaffected by external electromagnetic interference. The enhancement module provides additional data input and environmental information to improve indoor positioning accuracy. The security and alarm module monitors the safety status of employees and assets in real time based on positioning data.

[0095] The low-light communication module includes asset tags, an antenna, and a controller (i.e., a control module). Each asset tag (a form of the first optical module) integrates a battery, a microcontroller, an LED, and a photosensitive circuit (i.e., a photosensitive element) to communicate with the antenna and transmit information such as the asset's location and status. The antenna (a form of the second optical module) receives data from the asset tags, parses this data through the photosensitive circuit, and then transmits it to the controller. The controller is responsible for powering the antenna, data conversion and transmission, and communication with the relevant management system.

[0096] The visible light positioning module includes employee name tags, indoor lighting fixtures, and a location calculation module. Each employee name tag (another form of the first optical module) is equipped with a light-emitting diode (LED) to emit light signals. The indoor lighting fixtures (another form of the second optical module) have a positioning function, which captures the light signals emitted by the name tags and transmits the information to the location calculation module. The location calculation module uses triangulation to accurately calculate the employee's specific location and sends the location information to the controller.

[0097] The enhancement module includes an inertial measurement unit (IMU), a wireless communication module, and an environmental sensing module. The IMU is integrated into employee ID cards or asset tags to monitor employee movement or asset movement in real time. IMU data is fused with visible light positioning data to improve positioning accuracy and stability. The wireless communication module provides additional communication channels when necessary. The environmental sensing module includes temperature and humidity sensors to monitor indoor environmental parameters in real time, optimizing the positioning algorithm and improving positioning accuracy.

[0098] The working principle of the interference-free indoor rapid positioning system in this example is as follows:

[0099] The low-light communication device consists of three parts: asset tags, antennas, and controllers. The asset tags, with their built-in batteries, transmit data to the antenna in real time via LED lights. The duration of the LED lights' on / off cycles represents different meanings, thus transmitting data. These signals are received by antennas deployed indoors and analyzed by photosensitive circuits. The on / off cycles of ordinary lights do not conform to the visible light communication protocol and therefore cannot be analyzed. Only on / off cycles conforming to the visible light communication protocol can be analyzed. The reverse antenna sends relevant instructions to the asset tags, such as modifying the asset tag ID number. The analyzed data is transmitted to the controller, which further processes the data and communicates it with the relevant management system. In this way, the system can track and manage the location of assets in real time.

[0100] Each employee's name tag contains an LED that emits a high-speed, visible flashing signal to transmit information. The controller is installed on each lighting fixture and plugged into a power source for operation. This system can cover the range of indoor lighting. The fluorescent lights inside the building have positioning capabilities. As employees move around indoors with their name tags, the position of each fluorescent light is determined by a specific point. The light emitted by the name tag is recognized by the light fixture, which then determines the distance based on the duration of the data transmitted by the name tag. If the light is captured by two or more light fixtures simultaneously, the position calculation module uses triangulation to calculate the employee's exact location.

[0101] An inertial measurement unit (IMU) integrates a gyroscope and an accelerometer, enabling real-time measurement of an object's three-dimensional angular velocity and acceleration. In interference-free indoor rapid positioning systems, the IMU is integrated into employee ID cards or asset tags to monitor employee movement trajectories or asset movement in real time. Through data fusion, IMU assistance, and environmental perception, high-precision and high-reliability indoor positioning can be provided.

[0102] The cooperation between the security and alarm module and the low-light communication module: The security and alarm module receives data from asset tags in real time through the low-light communication module, including information such as the location and status of the assets. Once an anomaly is detected, such as an abnormal asset location or status, the security and alarm module can immediately send alarm information to the management personnel through the low-light communication module. The low-light communication module supports two-way communication, which means that the management personnel can not only receive alarm information through it, but also send commands or query information to the security and alarm module to realize remote management and control of alarm status.

[0103] Based on the data collected by the antenna, the following steps are performed:

[0104] S1: First, the data collected by the antenna is preprocessed. The preprocessing process includes cleaning the collected data to remove outliers and a large amount of duplicate data, so as to reduce the amount of calculation in the later stage and reduce the operating pressure on the server. Then, the data format is normalized (in this example, it is scaled based on the mean and standard deviation of the data) to ensure that the data are on the same scale.

[0105] S2: Extract features from the normalized data, such as edges, corners, and textures, from the visible light data.

[0106] Features such as changes in direction and rotation speed are extracted from gyroscope inertial data; features such as changes in temperature and humidity are extracted from environmental data.

[0107] S3: Then, a fusion algorithm is used to fuse the features extracted above. In this case, the Dempster evidence theory is selected to construct a trust function and a likelihood function, and then the Dempster combination rule is used for evidence fusion. The specific calculation steps of the Dempster evidence theory are as follows:

[0108] S3-1: First, define a problem framework X based on the requirements of this case. The problem includes all possible situations of the target's position and motion state.

[0109] S3-2: For each device i, obtain a basic probability assignment (BPA). The BPA distributes the probability across a subset A of X. For device i, calculate its BPA m. i , representing the degree of trust in subset A;

[0110] S3-3: Combine BPAs from different sensors using Dempster's combination rules. The combination rule is: m(A) = ∑ B∩C＝A m1(B)×m2(C), where m1 and m2 are the BPA of the two sensors respectively, A is a subset of X, and B and C are subsets that make B∩C=A;

[0111] S3-4: Calculate the trust function Bel and the likelihood function PI. The trust function represents the degree of trust in subset A. The calculation formula is as follows: The likelihood function represents the probability of a subset A occurring, and is calculated using the following formula: in It is the complement of A;

[0112] S3-5: Based on the results of the trust function and the likelihood function, make decisions and select the subset with the highest trust level as the basis for decision-making.

[0113] The coordination between the safety and alarm module and the visible light positioning module: The visible light positioning module provides the safety and alarm module with precise location information of employees or assets. When an employee or asset enters a preset danger zone, the safety and alarm module can accurately trigger an alarm based on the visible light positioning data and inform management personnel of the specific location information. Based on the positioning data from the visible light positioning module, the safety and alarm module can dynamically adjust the size and location of the alarm area to adapt to the needs of different scenarios, improving the accuracy and usability of the alarm.

[0114] The coordination between the safety and alarm module and the enhancement module: The inertial measurement module in the enhancement module can monitor the movement trajectory and status of employees or assets in real time. The safety and alarm module can combine this data to more accurately determine whether there are any safety hazards and trigger corresponding alarms. The environmental perception module in the enhancement module provides indoor environmental parameters, such as temperature and humidity. The safety and alarm module can use this data to determine whether the environment poses a threat to the safety of employees or assets. For example, excessively high temperature or humidity may cause certain equipment malfunctions, thus issuing an early alarm.

[0115] This example utilizes low-light communication and visible light positioning technologies to achieve rapid positioning, unaffected by external electromagnetic interference, ensuring accuracy and stability. It boasts low overall cost and wide applicability. Through data fusion algorithms, inertial measurement modules, and environmental sensing modules, this example provides high-precision and high-reliability indoor positioning. A safety and alarm module is included, which can work in conjunction with the low-light communication module, visible light positioning module, and enhancement module to monitor the safety status of employees and assets in real time, effectively improving security.

[0116] Embodiments of the present invention provide an indoor positioning method, applied to the indoor positioning system 10 provided in the above embodiments, such as... Figure 9 As shown, the method includes steps 901 to 904.

[0117] Step 901: The first optical module emits the first optical signal.

[0118] Step 902: The second optical module receives the first optical signal, parses the first optical signal to obtain the parsed first optical signal, and sends the parsed first optical signal to the control module.

[0119] Step 903: The control module receives the parsed first optical signal from the second optical module and transmits the parsed first optical signal to the position calculation module.

[0120] Step 904: The position calculation module receives the parsed first optical signal from at least two control modules, and determines the position of the first optical module based on the parsed first optical signal from at least two control modules and the triangulation algorithm.

[0121] The specific scheme and beneficial effects of the indoor positioning method provided by the embodiments of the present invention can be found in the relevant description of the indoor positioning system 10 provided by the embodiments of the present invention, which will not be repeated here.

[0122] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An indoor positioning system, characterized in that, include: At least one first optical module; the first optical module is used to emit a first optical signal; At least two second optical modules are used to receive the first optical signal, parse the first optical signal to obtain the parsed first optical signal, and send the parsed first optical signal to the control module. At least two control modules, each control module being configured to receive the parsed first optical signal from the second optical module and transmit the parsed first optical signal to the position calculation module; and The position calculation module is configured to receive the parsed first optical signal from at least two of the control modules, and determine the position of the first optical module based on the parsed first optical signal from at least two of the control modules and a triangulation algorithm.

2. The indoor positioning system according to claim 1, characterized in that, The second optical module is also used to send a second optical signal to the first optical module. The first optical module is also used to send a third optical signal based on the second optical signal when it receives the second optical signal. The third optical signal is used to determine the position of the first optical module. The frequency of the third optical signal is different from that of the first optical signal.

3. The indoor positioning system according to claim 2, characterized in that, The first optical module includes a power supply, a microcontroller unit (MCU), a light-emitting diode (LED), and a photosensitive element. The power supply provides power to the MCU, the LED, and the photosensitive element. The photosensitive element receives the second optical signal, converts the second optical signal into an electrical signal, and sends the electrical signal to the MCU. The MCU receives the electrical signal, generates a corresponding control signal based on the electrical signal, and sends the control signal to the LED. The control signal controls the blinking frequency of the LED. The LED receives the control signal and blinks according to the control signal.

4. The indoor positioning system according to claim 1, characterized in that, The first optical module is installed in the employee's ID card or asset tag.

5. The indoor positioning system according to claim 1, characterized in that, The second optical module and the control module are in one-to-one correspondence, and the second optical module and the control module corresponding to the second optical module are arranged in the indoor lamps according to a preset arrangement rule. The range of light signals received by all the second optical modules in at least two of the second optical modules includes all areas of the indoor space.

6. The indoor positioning system according to claim 1, characterized in that, It also includes an inertial measurement module, which corresponds one-to-one with the first optical module. The inertial measurement module is used to measure the three-dimensional angular velocity data and acceleration data of the first optical module, and transmits the three-dimensional angular velocity data and acceleration data of the first optical module to the position calculation module. The position calculation module is also used to determine the position of the first optical module based on the parsed first optical signal, the three-dimensional angular velocity data and acceleration data of the first optical module.

7. The indoor positioning system according to claim 1, characterized in that, It also includes an environmental sensing module, which is used to acquire indoor ambient temperature data and indoor ambient humidity data in real time, and send the indoor ambient temperature data and indoor ambient humidity data to the location calculation module. The location calculation module is also used to determine the position of the first optical module based on the parsed first optical signal, the indoor ambient temperature data and the indoor ambient humidity data.

8. The indoor positioning system according to claim 1, characterized in that, It also includes an alarm module, which is used to periodically acquire the position and working status of the first optical module, and issue alarm information when the position of the first optical module is abnormal or the working status of the first optical module is abnormal.

9. The indoor positioning system according to claim 1, characterized in that, The position calculation module is also used to preprocess the parsed first optical signal to obtain preprocessed data, and to extract features from the preprocessed data; and to determine the position of the first optical module based on the feature-extracted data and the triangulation algorithm.

10. The indoor positioning system according to claim 9, characterized in that, The position calculation module is further configured to acquire the three-dimensional angular velocity data of the first optical module, the acceleration data of the first optical module, the indoor ambient temperature data, and the indoor ambient humidity data; perform data fusion on the feature-extracted data, the three-dimensional angular velocity data of the first optical module, the acceleration data of the first optical module, the indoor ambient temperature data, and the indoor ambient humidity data according to a preset data fusion algorithm, and determine the position of the first optical module based on the data after data fusion and the triangulation algorithm.

11. The indoor positioning system according to claim 1, characterized in that, It also includes a wireless communication module, which is used to establish additional wireless transmission channels for the first optical module, the second optical module, the control module and the location calculation module.

12. An indoor positioning method, characterized in that, The method, applied to the indoor positioning system according to any one of claims 1 to 10, comprises: The first optical module emits a first optical signal; The second optical module receives the first optical signal, parses the first optical signal to obtain the parsed first optical signal, and sends the parsed first optical signal to the control module. The control module receives the parsed first optical signal from the first optical module and transmits the parsed first optical signal to the position calculation module; and The position calculation module receives the parsed first optical signal from at least two of the control modules, and determines the position of the first optical module based on the parsed first optical signal from at least two of the control modules and a triangulation algorithm.

Images