Fusion positioning method based on Bluetooth channel detection and ultra wide band ranging

Abstract

The invention relates to a fusion positioning method and system based on Bluetooth channel detection and ultra-wideband distance measurement, electronic equipment and a storage medium. The intelligent triggering of low-power-consumption initial distance measurement and fine positioning is realized by adopting a Bluetooth channel detection function; the ultra-wideband module is awakened as required for high-precision measurement; and based on the real-time channel quality index, dynamic weighted fusion is carried out on the ranging results of the Bluetooth and the ultra wide band. According to the invention, the technical problem that high precision and low power consumption cannot be considered at the same time in the prior art is solved, the UWB-level positioning precision is obtained at the power consumption cost close to Bluetooth, the positioning reliability and cruising ability of the system in a complex environment are remarkably improved, and a feasible technical scheme is provided for large-scale high-precision indoor positioning application.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ranging positioning, and in particular, to a fusion positioning method and system based on Bluetooth channel sounding and ultra-wideband ranging, a computer device, and a computer readable storage medium. BACKGROUND

[0002] Existing indoor positioning technologies mainly include ultra-wideband (UWB) positioning technology, Bluetooth positioning technology, etc.

[0003] In related technologies, the UWB positioning technology realizes ranging and positioning by measuring the time of flight (ToF) of an extremely narrow pulse signal, and its accuracy can reach centimeter level (e.g., 10-30 centimeters). However, the UWB technology also has inherent defects, such as high power consumption of the radio frequency chip of the terminal device and relatively high hardware cost, which become the constraints for its popularization in application scenarios that require the deployment of a large number of positioning tags (e.g., management of goods in a large warehouse).

[0004] The Bluetooth positioning technology, especially before the Bluetooth 5.1 standard, mainly performs positioning based on received signal strength indication (RSSI). This method has low accuracy, usually at the meter level, and the RSSI value is easily disturbed by complex indoor environments (such as obstacle shielding, personnel movement, multipath effect, etc.), resulting in poor stability of the positioning result. The Bluetooth 5.1 standard introduces angle of arrival (AOA) and angle of departure (AoD) measurement functions, which improve the positioning accuracy through angle information and can reach 0.5-1 meters. Although the accuracy has been improved, its performance will decrease significantly in environments with severe multipath effect, and it usually needs to deploy multiple base stations to achieve good coverage and accuracy, and its accuracy level is still not comparable to the UWB technology.

[0005] Therefore, the existing technology lacks an indoor positioning scheme that can simultaneously meet the requirements of high accuracy, low power consumption, and low cost. SUMMARY

[0006] Embodiments of the present application provide a fusion positioning method and system based on Bluetooth channel sounding and ultra-wideband ranging, a computer device, and a computer readable storage medium, to at least solve the problem that indoor positioning methods in related technologies cannot simultaneously meet the requirements of high accuracy and low accuracy.

[0007] In a first aspect, embodiments of the present application provide a fusion positioning method based on Bluetooth channel sounding and ultra-wideband ranging, the method comprising: initially ranging the positioning terminal through the Bluetooth channel sounding function to obtain a first ranging result and a first channel quality index corresponding to the first ranging result; judging whether a fine positioning trigger condition is met based on the first ranging result; if yes, waking up an ultra-wideband module of the positioning terminal and performing high-precision ranging through the ultra-wideband module to obtain a second ranging result and a second channel quality index corresponding to the second ranging result; dynamically assigning trust weights to the first ranging result and the second ranging result based on the first channel quality index and the second channel quality index; adopting a fusion positioning algorithm to perform weighted fusion processing on the first ranging result and the second ranging result according to the trust weights, obtaining a final high-precision coordinate of the positioning terminal according to the calculation, and controlling the ultra-wideband module to return to a low-power state after the calculation is completed.

[0008] In some embodiments, the fine positioning trigger condition includes at least one of the following: the first ranging result is less than a preset distance threshold, the positioning terminal initiatively initiates a high-precision positioning request through a physical button or a software interface, and the positioning terminal is polled according to a preset strategy; sending an instruction through the Bluetooth channel to trigger the UWB module of the positioning terminal to start to perform the fine positioning.

[0009] In some embodiments, the first channel quality index includes delay spread calculated according to channel impulse response data of the Bluetooth channel sounding, RSSI stability, and historical data consistency. The second channel quality index includes a power ratio of a first path power to a strongest path power extracted according to channel impulse response data of the ultra-wideband ranging.

[0010] In some embodiments, dynamically assigning trust weights to the first ranging result and the second ranging result includes: when the delay spread of the Bluetooth channel sounding is less than a first preset threshold and the RSSI fluctuation is smooth, it is determined that the Bluetooth channel is in line of sight or in a stable transmission environment, a first weight interval of trust weights is assigned to the first ranging result, and a second weight interval of trust weights is assigned to the second ranging result; when the delay spread of the Bluetooth channel sounding is greater than a second preset threshold and the power ratio is less than a second preset threshold, it is determined that the Bluetooth channel is in non-line-of-sight or a strong multipath transmission environment, the trust weight assigned to the first ranging result is reduced, and the trust weight assigned to the second ranging result is increased.

[0011] In some embodiments, the method further includes: when the signal quality of the Bluetooth channel sounding is continuously lower than a preset quality threshold within a preset period, configuring a trust weight of the first ranging result as zero, and performing positioning calculation according to a second ranging result of the ultra-wideband ranging; and synchronously increasing a state estimation uncertainty covariance of a positioning result in the fusion positioning algorithm.

[0012] In some embodiments, the fusion positioning algorithm is a Kalman filter algorithm or a particle filter algorithm, and the state estimation and smoothing filtering are achieved by the following steps: establishing a motion model based on a historical motion state of the positioning terminal, and predicting a prior state at a current time according to the motion model; taking the Bluetooth channel sounding and the ultra-wideband ranging information fused through the trust weight as an observation value, correcting and updating the prior state by using the observation value to obtain an optimal posterior state estimation at the current time, and outputting a smooth and continuous positioning coordinate trajectory based on the optimal posterior state.

[0013] In some embodiments, the method further comprises: monitoring a motion state of the positioning terminal; when it is judged that the positioning terminal is in a stationary state within a preset time length, prolonging a time interval at which the ultra-wideband module is woken up or suspending triggering to reduce average power consumption of the terminal in a stationary scenario.

[0014] In a second aspect, the application provides a fusion positioning system based on Bluetooth channel sounding and ultra-wideband ranging, the system comprising: an acquisition module, a judgment and decision module and a positioning module, wherein: the acquisition module is configured to perform initial ranging on a positioning terminal by a Bluetooth channel sounding function to acquire a first channel quality indicator corresponding to a first ranging result; the judgment and decision module is configured to judge whether a fine positioning triggering condition is met based on the first ranging result; if yes, waking up an ultra-wideband module of the positioning terminal, and performing high-precision ranging by the ultra-wideband module to acquire a second ranging result and a corresponding second channel quality indicator; dynamically allocating trust weights to the first ranging result and the second ranging result based on the first channel quality indicator and the second channel quality indicator; the positioning module is configured to adopt a fusion positioning algorithm, to perform weighted fusion processing on the first ranging result and the second ranging result according to the trust weights, to calculate a final high-precision coordinate of the positioning terminal, and to control the ultra-wideband module to return to a low-power state after the calculation is completed.

[0015] In a third aspect, an embodiment of the present application provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method according to the first aspect when executing the computer program.

[0016] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, having stored thereon a computer program, which, when executed by a processor, implements the method according to the first aspect.

[0017] Compared with the related art, the fusion positioning method and system based on Bluetooth channel sounding and ultra-wideband ranging provided by the embodiment of the present application realizes low-power initial ranging and intelligent triggering of precise positioning by adopting the Bluetooth channel sounding function; the ultra-wideband module is awakened on demand for high-precision measurement; and the ranging results of Bluetooth and ultra-wideband are dynamically weighted and fused based on real-time channel quality indicators. The present application solves the technical problem that high precision and low power consumption cannot be considered in the related art, realizes UWB-level positioning precision at the power consumption cost close to Bluetooth, significantly improves the positioning reliability and endurance of the system in a complex environment, and provides a feasible technical solution for large-scale high-precision indoor positioning applications. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings described herein are used to provide further understanding of the present application, form a part of the present application, and are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings: Figure 1 is a flowchart of a fusion positioning method based on Bluetooth channel sounding and ultra-wideband ranging according to an embodiment of the present application; Figure 2 is a structural block diagram of a fusion positioning system based on Bluetooth channel sounding and ultra-wideband ranging according to an embodiment of the present application; Figure 3 is a system execution flow schematic diagram according to an embodiment of the present application; Figure 4 is a schematic diagram of the internal structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is described and explained below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0020] It is apparent that the drawings in the following description merely show some examples or embodiments of the present application, and the present application can be applied to other similar situations without creative labor by those skilled in the art based on these drawings. In addition, it can be understood that although the efforts made in the development process can be complex and lengthy, some modifications, such as design, manufacture or production, etc. based on the technical content disclosed in the present application, are only routine technical means for those skilled in the art related to the content disclosed in the present application, and should not be understood as insufficient disclosure of the content disclosed in the present application.

[0021] Reference to "an embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is explicitly contemplated that embodiments described herein can be combined with other embodiments in a non- conflicting manner.

[0022] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the ordinary meaning understood by one of ordinary skill in the art to which the present application pertains. The terms "a", "an", "one", "the", and similar terms in the present application do not denote a limitation on quantity but rather denote the presence of at least one of the referenced item. The terms "including", "comprising", "having" and their variants in the present application are intended to cover non-exclusive inclusion; for example, processes, methods, systems, products, or devices that include a series of steps or modules (units) are not limited to the listed steps or units, but can also include other steps or units not listed, or can also include other steps or units inherent to these processes, methods, products or devices. The terms "connected", "connected", "coupled" and similar terms in the present application are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The term "multiple" in the present application means two or more. The term "and / or" describes the association relationship between the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects. The terms "first", "second", "third" and the like in the present application are merely to distinguish similar objects, and do not represent a specific order for the objects.

[0023] To solve the problem that high precision, low power consumption and low cost cannot be considered in the prior art, the embodiment of the present application provides a fusion positioning method based on Bluetooth channel sounding and ultra-wideband ranging. The method creatively combines the channel sounding (CS) function in Bluetooth technology (for example, Bluetooth 6.0) with UWB technology, and through an intelligent fusion algorithm, the respective advantages of the two technologies are brought into play in different scenarios, and the disadvantages are made up, so that high-precision positioning is realized while keeping low power consumption and low cost.

[0024] Figure 1 is a flowchart of a fusion positioning method based on Bluetooth channel sounding and ultra-wideband ranging according to the embodiment of the present application, as Figure 1 shown, the flow includes the following steps: S101, initial ranging of the positioning terminal is performed through the Bluetooth channel sounding function, and a first channel quality index corresponding to a first ranging result is obtained.

[0025] In an embodiment, after the positioning terminal is powered on or wakes up from the sleep state, existence detection and coarse positioning are first performed through Bluetooth broadcasting. After the positioning base station in the positioning system receives the broadcast signal, the Bluetooth connection with the positioning terminal is established, and one or more channel sounding sessions are initiated. The Bluetooth channel sounding function can provide more accurate distance information than the traditional RSSI by transmitting a series of known sounding sequences and analyzing the channel impulse response (CIR) of the received signal. The initial ranging result, i.e., the first ranging result, has a expected accuracy of within 0.5 meters, which is used for preliminary regional positioning of the positioning terminal.

[0026] In addition, while the initial ranging is being performed, the current Bluetooth channel quality is evaluated in real time to generate a first channel quality index. Specifically, the first channel quality index can include, but is not limited to, one or a combination of the following: 1) Delay spread calculated from CIR data obtained by Bluetooth channel sounding. Delay spread reflects the degree of dispersion of multipath signals in time, and the greater the delay spread, the more serious the multipath effect, the more complex the channel environment, and the lower the reliability of the ranging result.

[0027] 2) Stability of received signal strength (RSSI). By monitoring the fluctuation of RSSI value over a period of time, if the RSSI fluctuates sharply, it indicates that the channel may be unstable or there may be interference.

[0028] 3) Consistency of historical data. The current ranging result is compared with the historical ranging data, and if there is a sudden change that does not match the historical trend, it may indicate that the current measurement is abnormal.

[0029] The step S101 performs preliminary ranging and evaluates channel quality through Bluetooth channel detection, provides decision basis for subsequent precise positioning triggering and data fusion, effectively reduces the frequency of blindly starting high-power modules of the system, and preliminarily realizes power consumption optimization.

[0030] S102, judging whether the precise positioning triggering condition is met based on the first ranging result.

[0031] This step is a key link to realize system power consumption optimization. In this embodiment, the UWB module with high power consumption is not always enabled. Based on the preliminary result of Bluetooth channel detection, it is intelligently judged whether the high-precision positioning needs to be started.

[0032] The precise positioning triggering condition can include at least one of the following: 1) The first ranging result is less than a preset distance threshold. For example, when the system judges that the positioning terminal enters a certain key area (such as a specific shelf area of a warehouse or the doorway of an operating room of a hospital), the distance between the terminal and the base station is less than the preset 5 meters, the precise positioning is triggered.

[0033] 2) The positioning terminal initiatively initiates a high-precision positioning request through a physical button or a software interface. For example, an emergency (SOS) button is arranged on the label worn by the personnel, or an operation is performed on the application software interface to actively request a high-precision positioning.

[0034] 3) The positioning terminal is polled according to a preset strategy. The system can set different high-precision positioning update frequencies for terminals with different priorities. When the polling period arrives, the precise positioning is triggered.

[0035] If the judgment result is that the preset condition is met, the subsequent step is executed; if not, the positioning terminal can continue to maintain the Bluetooth low-power listening state, and the UWB module is not started, thereby saving the power consumption.

[0036] This step S102 adopts an intelligent triggering mechanism, and starts the high-precision positioning only when necessary, realizes the principle of "working on demand", greatly reduces the average power consumption of the terminal in a non-key area or a stationary state, and significantly prolongs the endurance time of the terminal.

[0037] S103, if yes, waking up the ultra-wideband module of the positioning terminal, and performing high-precision ranging through the ultra-wideband module to obtain a second ranging result and a corresponding second channel quality index.

[0038] When the triggering condition is met, the positioning base station can send a specific instruction to the positioning terminal through the Bluetooth channel. The instruction is used to wake up (i.e., power on and start) the UWB radio frequency module on the terminal. After the UWB module is woken up, it immediately performs one or more high-precision rangings with one or more base stations.

[0039] Specifically, the UWB ranging can employ technologies such as Two-Way Ranging (TWR) or Phase Difference of Arrival (PDoA) to obtain centimeter-level accurate distance and / or angle information as the second ranging result. It can be understood that the UWB ranging plays the role of an "accuracy arbitrator" in the method, and its high-precision measurement value provides a key basis for the final coordinate solution. At the same time, when the Bluetooth CS signal is severely interfered and has low confidence, the UWB data can be supplemented or replaced as core data to ensure the reliability of positioning.

[0040] Similar to Bluetooth ranging, the channel quality is evaluated synchronously during UWB ranging to generate a second channel quality index.

[0041] Specifically, the second channel quality index can include a power ratio of a first path power to a maximum path power extracted from CIR data of UWB ranging.

[0042] In a line-of-sight (LOS) environment, the first arrival path of the signal is usually the path with the strongest energy, and the ratio is close to 1. In a non-line-of-sight (NLOS) or strong multipath environment, the strongest path can be a reflected path, and its power can be much higher than that of the first arrival path, resulting in a significant decrease in the ratio.

[0043] Therefore, the power ratio can be used as an important basis for judging whether the UWB channel has NLOS or strong multipath effect.

[0044] This step S103 obtains centimeter-level ranging data and channel indicators through the on-demand wake-up UWB module, providing a high-precision data source for the system and ensuring positioning accuracy at critical moments, while providing a basis for judging the channel environment for subsequent intelligent fusion.

[0045] S104, based on the first channel quality index and the second channel quality index, dynamically assigning trust weights to the first ranging result and the second ranging result.

[0046] It should be noted that the traditional fusion algorithm assigns fixed weights to different data sources, while the trust weight in the embodiments of the present application changes dynamically according to real-time channel quality. The present scheme assigns a weight w_ble to the Bluetooth ranging result and a weight w_uwb to the UWB ranging result, and satisfies w_ble+w_uwb=1. The greater the weight value, the higher the degree of trust of the fusion algorithm for the data source at the current time.

[0047] Specifically, the logic of weight distribution in this embodiment can be based on a weight distribution function that maps the channel quality indicators obtained in S101 and S103 to specific weight values.

[0048] In a rule-based embodiment, the weight distribution logic is as follows: 1) When the delay spread of the Bluetooth channel probe is less than a first preset threshold, and the RSSI variation is smooth, it is determined that the Bluetooth channel is in line of sight, or in a stable transmission environment. The first ranging result is assigned a trust weight in a first weight interval, and the second ranging result is assigned a trust weight in a second weight interval. At this time, the ranging result of the Bluetooth CS is highly reliable, and a higher trust weight w_ble (for example, 0.7-0.95) is assigned to it, while a lower trust weight w_uwb (for example, 0.05-0.3) is assigned to the UWB ranging result. At this time, UWB mainly plays an auxiliary and backup role.

[0049] 2) When the delay spread of the Bluetooth channel probe is greater than a second preset threshold, and the power ratio is less than a second preset threshold, it is determined that the Bluetooth channel is in a non-line-of-sight or strong multipath transmission environment, the trust weight assigned to the first ranging result is reduced, and the trust weight assigned to the second ranging result is increased. At this time, the system determines that the Bluetooth channel data is less reliable, and w_ble is significantly reduced (for example, to 0.2), while w_uwb is increased (for example, to 0.8).

[0050] Further, in some extreme cases, when the signal quality of the Bluetooth channel probe is continuously below a preset quality threshold for a preset period of time, the trust weight of the first ranging result can be configured to zero, and the positioning is calculated entirely based on the second ranging result of the ultra-wideband ranging. At the same time, the state estimation uncertainty covariance of the positioning result is increased synchronously in the fusion positioning algorithm.

[0051] This step S104 dynamically adjusts the trust weight of different data sources based on real-time channel quality indicators. This adaptive weighting mechanism ensures that the system always prioritizes more reliable ranging data, thereby greatly improving the positioning stability and final accuracy in complex and variable environments (especially in NLOS scenarios), and is the key to achieving high-reliability fusion.

[0052] S105, a fusion positioning algorithm is used to perform weighted fusion processing on the first ranging result and the second ranging result according to the trust weight, and the final high-precision coordinates of the positioning terminal are calculated, and after the calculation is completed, the ultra-wideband module is controlled to return to a low-power state.

[0053] Wherein, the positioning engine server receives the Bluetooth CS and UWB ranging information with trust weight, and adopts a fusion positioning algorithm to calculate the final coordinates. The fusion positioning algorithm can be Kalman Filter algorithm or Particle Filter algorithm, and state estimation and smoothing filtering are realized through the following steps: 1) Establish a motion model based on the historical motion state of the positioning terminal, and predict the prior state at the current time according to the motion model.

[0054] 2) The Bluetooth channel detection and UWB ranging information fused by the trust weight are taken as observation values, and the observation values are used to correct and update the prior state to obtain the optimal posterior state estimation at the current time. Based on the optimal posterior state, a smooth and continuous positioning coordinate trajectory is output.

[0055] Through the iterative process of prediction and update, the algorithm can not only output the optimal position solution at the current time, but also effectively suppress the noise and mutation of single measurement.

[0056] After completing the coordinate solution, the system immediately sends instructions through the Bluetooth channel to control the UWB module of the terminal to turn off the power or return to a low-power state such as deep sleep, so as to maximize the saving of power and realize the power optimization strategy of "starting on demand and turning off after use".

[0057] This step S105 uses Kalman filtering algorithm to perform optimal estimation on the weighted multi-source data, and outputs smooth high-precision coordinates, and then closes the UWB module, which not only ensures the quality of the positioning result, but also completes the closed loop of power optimization, and is the key execution link to realize the overall performance goal of the system.

[0058] Through the complete process of S101 to S105, the method provided by the embodiment of the application realizes the effective balance between power consumption and accuracy through the strategy of "Bluetooth always on and UWB starting on demand"; through dynamic weight distribution based on real-time channel quality, the reliability and stability of the fusion result in complex environments are improved; through Kalman filtering algorithm, smooth and continuous high-precision positioning output is realized. Finally, an efficient, accurate, reliable and power and cost optimized solution for indoor positioning is provided.

[0059] In some embodiments, the method further comprises: monitoring the motion state of the positioning terminal; when it is judged that the positioning terminal is in a stationary state within a preset time length, extending the time interval of the wake-up of the ultra-wideband module or pausing the triggering to reduce the average power consumption of the terminal in a stationary scenario. In addition, the motion state can be monitored by sensors such as accelerometers built into the terminal. When it is judged that the terminal is in a stationary state within a preset time length (for example, 5 minutes), the time interval of the wake-up of the UWB module of the terminal can be automatically extended (for example, from 30 seconds to 5 minutes), or the UWB module can be paused when the terminal is completely stationary, thereby greatly reducing the average power consumption of the terminal in a stationary scenario.

[0060] The optional embodiment intelligently schedules the UWB wake-up frequency by monitoring the motion state of the terminal, further reduces the energy consumption of the terminal in a stationary or low-activity scenario, makes the overall power consumption management more refined, and maximizes the service life of the device.

[0061] The present application also provides a fusion positioning system based on Bluetooth channel sounding and ranging, Figure 2 is a structural block diagram of a fusion positioning system based on Bluetooth channel sounding and ultra-wideband ranging according to an embodiment of the present application, as Figure 2 shown, the system comprises an acquisition module 20, a judgment and decision module 21 and a positioning module 22.

[0062] The acquisition module 20 is configured to perform initial ranging on the positioning terminal through the Bluetooth channel sounding function, and acquire a first channel quality index corresponding to a first ranging result; The judgment and decision module 21 is configured to judge whether the fine positioning triggering condition is met based on the first ranging result; if so, wake up the ultra-wideband module of the positioning terminal, and perform high-precision ranging through the ultra-wideband module to acquire a second ranging result and a corresponding second channel quality index; and dynamically allocate trust weights to the first ranging result and the second ranging result based on the first channel quality index and the second channel quality index. The positioning module 22 is configured to adopt a fusion positioning algorithm, perform weighted fusion processing on the first ranging result and the second ranging result according to the trust weights, obtain the final high-precision coordinates of the positioning terminal according to the calculation, and control the ultra-wideband module to return to a low-power state after the calculation is completed.

[0063] In one embodiment, the hardware architecture of the system comprises: 1) Dual-mode positioning base station / anchor point: Bluetooth (supporting channel sounding) and UWB radio frequency chips are integrated on the hardware at the same time, and are deployed in an indoor environment.

[0064] 2) Dual-mode positioning terminal / tag: also designed as a dual-mode hardware, worn on a person or attached to an asset. The on-off state of the UWB module is controlled by the instructions received through the Bluetooth channel.

[0065] 3) Positioning Engine Server: used to run the system modules of the present embodiment, receive raw measurement data from base stations, run fusion positioning algorithms, and output final coordinates.

[0066] Figure 3 is a system execution flow diagram according to the embodiments of the present application, combined with Figure 3 the flow, taking the positioning of a forklift in a smart warehouse as an example, to explain the actual operation of the system: After the forklift equipped with the dual-mode positioning terminal described in the present application is started, its Bluetooth module begins to broadcast, and the positioning base station performs initial ranging through the Bluetooth channel sounding (CS) function, obtaining a preliminary positioning result with a distance of 8 meters. At this time, the precision positioning trigger condition of less than 5 meters is not met, and the terminal only maintains a Bluetooth low-power listening state.

[0067] When the forklift enters the high-value goods area, the CS ranging result is updated to 4 meters, meeting the distance threshold condition, and the system determines that high-precision positioning is needed. At this time, the positioning base station sends a command to wake up the UWB module of the forklift terminal. The UWB module immediately performs several high-precision time-of-flight (ToF) ranging with multiple base stations around it.

[0068] After receiving the 4-meter ranging result of the Bluetooth CS and the centimeter-level ranging result of the UWB, the positioning engine server analyzes the channel quality indicators of the two. If it is found that the delay spread of the Bluetooth signal is large, while the first path power ratio of the UWB signal is high, then the UWB data is assigned a higher trust weight (e.g. 0.85), and the Bluetooth data is assigned a lower weight (e.g. 0.15). Finally, through the Kalman filtering algorithm, the weighted data is fused to solve the final coordinates of the forklift, with an accuracy of 15 centimeters. After the coordinate update is completed, the UWB module is instructed to be turned off and return to a low-power state until the next time the trigger condition is met.

[0069] Through the above system, the Bluetooth channel sounding function is used to achieve low-power initial ranging and intelligent triggering of precision positioning; the ultra-wideband module is awakened on demand for high-precision measurement; and the ranging results of Bluetooth and ultra-wideband are dynamically weighted and fused based on real-time channel quality indicators. The present application solves the technical problem that high precision and low power consumption cannot be considered in related technologies, realizes UWB-level positioning accuracy at the power consumption cost of Bluetooth, significantly improves the positioning reliability and endurance of the system in complex environments, and provides a feasible technical solution for large-scale high-precision indoor positioning applications.

[0070] In one embodiment, Figure 4 is an internal structure diagram of an electronic device according to the embodiments of the present application, as Figure 4As shown, an electronic device, which can be a server, is provided. An internal structure diagram of the electronic device can be as shown. Figure 4 The electronic device includes a processor, a network interface, an internal memory and a non-volatile memory connected through an internal bus, wherein the non-volatile memory stores an operating system, a computer program and a database. The processor is configured to provide computing and control capabilities, the network interface is configured to communicate with an external terminal through a network connection, the internal memory is configured to provide an environment for the operating system to run, the computer program is executed by the processor to implement a fusion positioning method based on Bluetooth channel sounding and ultra-wideband ranging, and the database is configured to store data.

[0071] Those skilled in the art can understand that Figure 4 The structure shown in the above embodiment is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. The specific electronic device can include more or fewer components than those shown in the diagram, or combine certain components, or have a different arrangement of components.

[0072] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by computer program instruction related hardware. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM) and memory bus dynamic RAM (RDRAM) and the like.

[0073] The technical features of the above embodiments can be combined in any way. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0074] The above embodiments only express several implementation ways of the present application, and the description is specific and detailed, but it should not be understood as a limitation to the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A fusion positioning method based on Bluetooth channel detection and ultra-wideband ranging, characterized in that, The method includes: The positioning terminal is initially ranged using the Bluetooth channel detection function to obtain the first channel quality index corresponding to the first ranged result. Based on the first ranging result, determine whether the fine positioning trigger condition is met; If so, the ultra-wideband module of the positioning terminal is activated, and high-precision ranging is performed through the ultra-wideband module to obtain the second ranging result and the corresponding second channel quality index. Based on the first channel quality index and the second channel quality index, trust weights are dynamically assigned to the first ranging result and the second ranging result. A fusion positioning algorithm is adopted to perform weighted fusion processing on the first ranging result and the second ranging result according to the trust weight. The final high-precision coordinates of the positioning terminal are obtained by calculation, and the ultra-wideband module is controlled to return to a low-power state after the calculation is completed.

2. The method according to claim 1, characterized in that, The precise positioning trigger condition includes at least one of the following: The first ranging result is less than a preset distance threshold, the positioning terminal actively initiates a high-precision positioning request through a physical button or software interface, and the positioning terminal is polled periodically according to a preset strategy; The positioning terminal's UWB module is activated by sending a command via the Bluetooth channel to perform the precise positioning.

3. The method according to claim 1, characterized in that, The first channel quality metrics include: delay spread, RSSI stability, and historical data consistency calculated based on channel impulse response data obtained from Bluetooth channel probing. The second channel quality metric includes the power ratio of the first path power to the strongest path power extracted from the channel impulse response data of ultra-wideband ranging.

4. The method according to claim 3, characterized in that, Dynamically assigning trust weights to the first and second ranging results includes: When the delay spread of the Bluetooth channel detection is less than a first preset threshold and the RSSI changes smoothly, it is determined that the Bluetooth channel is at line of sight or in a stable transmission environment. A trust weight of a first weight interval is assigned to the first ranging result, and a trust weight of a second weight interval is assigned to the second ranging result. When the delay spread of the Bluetooth channel detection is greater than a second preset threshold and the power ratio is less than a second preset threshold, it is determined that the Bluetooth channel is in a non-line-of-sight or strong multipath transmission environment, the trust weight assigned to the first ranging result is reduced, and the trust weight assigned to the second ranging result is increased.

5. The method according to claim 4, characterized in that, The method further includes: If the signal quality detected by the Bluetooth channel is continuously lower than a preset quality threshold within a preset time period, the trust weight of the first ranging result is configured to zero, and the positioning solution is performed based on the second ranging result of the ultra-wideband ranging. Furthermore, the state estimation uncertainty covariance of the positioning result is increased synchronously in the fusion positioning algorithm.

6. The method according to claim 1, characterized in that, The fusion localization algorithm is either a Kalman filter algorithm or a particle filter algorithm, and it achieves state estimation and smoothing filtering through the following steps: A motion model is established based on the historical motion state of the positioning terminal, and the prior state at the current moment is predicted based on the motion model. The Bluetooth channel detection and ultra-wideband ranging information fused with trust weights are used as observations. The prior state is corrected and updated using the observations to obtain the optimal posterior state estimate at the current moment. Based on the optimal posterior state, a smooth and continuous positioning coordinate trajectory is output.

7. The method according to claim 1, characterized in that, The method further includes: Monitor the motion status of the positioning terminal; When it is determined that the positioning terminal is stationary within a preset time period, the time interval for waking up the ultra-wideband module is extended or the triggering is paused to reduce the average power consumption of the terminal in a stationary scenario.

8. A fusion positioning system based on Bluetooth channel detection and ultra-wideband ranging, characterized in that, The system includes: an acquisition module, a judgment and decision module, and a positioning module, wherein: The acquisition module is used to perform initial ranging on the positioning terminal through the Bluetooth channel detection function, and acquire the first channel quality index corresponding to the first ranging result machine. The judgment and decision module is used to determine whether the fine positioning trigger condition is met based on the first ranging result. If so, the ultra-wideband module of the positioning terminal is activated, and high-precision ranging is performed through the ultra-wideband module to obtain the second ranging result and the corresponding second channel quality index. Based on the first channel quality index and the second channel quality index, trust weights are dynamically assigned to the first ranging result and the second ranging result. The positioning module is used to employ a fusion positioning algorithm to perform weighted fusion processing on the first ranging result and the second ranging result according to the trust weight, obtain the final high-precision coordinates of the positioning terminal based on the calculation, and control the ultra-wideband module to return to a low-power state after the calculation is completed.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 7.

Images