Wireless distance correction method, wireless positioning correction method, wireless positioning system and storage medium

Abstract

The invention discloses a wireless distance correction method, a wireless positioning correction method, a wireless positioning system and a storage medium. The wireless distance correction method comprises the following steps: acquiring a calculated distance with other wireless gateways and a calculated distance with a beacon anchor point through wireless distance measurement; the actual distance between the wireless gateway and other wireless gateways is obtained; the calculated distance of the beacon anchor point is corrected based on the calculated distance and the actual distance with the other wireless gateways. According to the invention, the error characteristic measured from the'gateway-gateway 'link can be used for correcting the measurement result of the'gateway-beacon anchor' link. Due to the fact that the actual distance between the gateways is known, the error characteristic of wireless distance measurement on the link between the gateways in the current environment can be accurately calculated, the measurement result of the'gateway-beacon anchor 'link is corrected, and the wireless distance calculation error caused by environmental factors is reduced.

Description

Technical Field

[0001] This invention relates to the field of wireless positioning technology, and in particular to a wireless distance correction method, a wireless positioning correction method, a wireless positioning system, and a storage medium. Background Technology

[0002] In systems that rely on wireless signal strength (such as RSSI) for distance estimation and positioning, signal propagation attenuation models (such as logarithmic path loss models) are typically used to convert the received signal strength into corresponding distance information. This type of method is widely used in applications such as indoor navigation, asset tracking, and personnel positioning due to its low hardware cost and relatively simple deployment.

[0003] However, in existing technologies, when wireless devices such as Bluetooth beacons estimate their location, various radio frequency interference factors in the environment (such as RF reflection, absorption, shielding, and metallic effects) cause the RSSI value of the same distance to vary greatly in different environments and at different times. This results in a large error between the "theoretical distance" calculated based on a fixed signal attenuation model and the actual physical distance. Summary of the Invention

[0004] The main objective of this invention is to provide a wireless distance correction method that aims to reduce the error in wireless distance calculation caused by environmental factors.

[0005] To achieve the above objectives, the wireless distance correction method proposed in this invention is applied to a wireless gateway in a wireless positioning system; the wireless positioning system includes: a beacon anchor point and multiple wireless gateways; The wireless distance correction method includes: The calculated distances between the device and other wireless gateways, as well as the calculated distances with the beacon anchor point, are obtained through wireless ranging. Obtain the actual distance between the device and other wireless gateways; The calculated distance of the beacon anchor point is corrected based on the calculated distance and the actual distance between it and other wireless gateways.

[0006] Optionally, correcting the calculated distance of the beacon anchor point based on the calculated distance and actual distance to other wireless gateways includes: Calculate the correction factor based on the calculated distance and actual distance between the device and other wireless gateways; The product of the correction factor and the calculated distance of the beacon anchor point is used as the corrected distance of the beacon anchor point.

[0007] Optionally, obtaining the actual distance to other wireless gateways then includes: Based on the calculated distances to other wireless gateways and the calculated distances to beacon anchor points, the distance weighting coefficients for the corresponding wireless gateways are determined. The calculated distance of the beacon anchor point is corrected based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, as well as the distance weighting coefficients corresponding to the multiple wireless gateways.

[0008] Optionally, determining the distance weighting coefficient for the corresponding wireless gateway based on the calculated distance to other wireless gateways and the calculated distance to the beacon anchor point includes: Based on a preset monotonically decreasing function, the distance weights of other wireless gateways are obtained according to the calculated distances with other wireless gateways. The distance weights of the other wireless gateways are normalized to determine the distance weight coefficients of the other wireless gateways.

[0009] Optionally, the step of obtaining the actual distance to other wireless gateways further includes: Obtain the azimuth angle of the beacon anchor point and the azimuth angles of other wireless gateways; A wireless gateway is identified where the difference between its azimuth angle and the beacon anchor point's azimuth angle falls within a first angle range, and the difference between its calculated distance and the calculated distance to the beacon anchor point falls within a set distance range. The calculated distance to the beacon anchor point is then corrected using the calculated distance to the wireless gateway and the actual distance to the beacon anchor point. The absolute value of the difference between the angle within the first angle range and 180° is less than a preset angle value.

[0010] Optionally, the step of obtaining the calculated distance between the wireless gateway and the beacon anchor point through wireless ranging includes: Collect the RSSI values ​​of other wireless gateways and the RSSI values ​​of the beacon anchor point; Based on the RSSI values ​​of the other wireless gateways, the calculated distance to other wireless gateways is determined; The calculated distance of the beacon anchor point is determined based on its RSSI value.

[0011] Optionally, the step of collecting the RSSI values ​​of other wireless gateways and the RSSI value of the beacon anchor point then includes: The RSSI values ​​of the other wireless gateways and the RSSI values ​​of the beacon anchors are filtered. Based on the filtered RSSI values ​​of the other wireless gateways, the calculated distance to other wireless gateways is determined. The calculated distance of the beacon anchor point is determined based on the filtered RSSI value of the beacon anchor point.

[0012] The present invention also proposes a wireless positioning correction method, the wireless positioning correction method comprising: Obtain the calculated distance between each wireless gateway, and the calculated distance between each wireless gateway and the beacon anchor point; Based on the calculated and actual distances between each wireless gateway, the calculated distances between each wireless gateway and the beacon anchor point are corrected. The location of the beacon anchor point is determined based on the corrected calculated distances of each wireless network to the beacon anchor point.

[0013] The present invention also proposes a wireless positioning system, including a beacon anchor point and multiple wireless gateways; The beacon anchor point is used to transmit wireless signals; The plurality of wireless gateways are used to emit wireless signals, collect wireless signals from other wireless gateways, and calculate the computational distance to other wireless gateways. The plurality of wireless gateways are also used to collect the wireless signal of the beacon anchor point, calculate the calculated distance to the beacon anchor point, and correct the calculated distance of the beacon anchor point based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, and determine the location of the beacon anchor point.

[0014] The present invention also proposes a storage medium storing a wireless distance correction program, which, when executed by a processor, implements the steps of the wireless distance correction method.

[0015] This invention discloses a wireless distance correction method, comprising: obtaining calculated distances between the beacon and other wireless gateways and the beacon anchor point through wireless ranging; obtaining the actual distances between the beacon and other wireless gateways; and correcting the calculated distances of the beacon anchor point based on the calculated distances between the beacon and other wireless gateways and the actual distances. This invention utilizes the error characteristics measured from the "gateway-to-gateway" link to correct the measurement results of the "gateway-to-beacon anchor point" link. Since the actual distances between gateways are known, the error characteristics of wireless ranging on the gateway-to-gateway link under the current environment can be accurately calculated, thereby correcting the measurement results of the "gateway-to-beacon anchor point" link and reducing the error in wireless distance calculation caused by environmental factors. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1This is a schematic diagram illustrating the steps of an embodiment of the wireless distance correction method of the present invention; Figure 2 This is a schematic diagram illustrating the steps of another embodiment of the wireless distance correction method of the present invention; Figure 3 This is a schematic diagram illustrating the steps of another embodiment of the wireless distance correction method of the present invention; Figure 4 This is a schematic diagram illustrating the steps of another embodiment of the wireless distance correction method of the present invention; Figure 5 This is a schematic diagram illustrating the steps of another embodiment of the wireless distance correction method of the present invention.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0023] This invention proposes a wireless distance correction method, which is applied to a wireless gateway in a wireless positioning system; the wireless positioning system includes: a beacon anchor point and multiple wireless gateways.

[0024] It should be noted that beacon anchors are typically the targets to be located, such as a Bluetooth beacon, whose precise location is unknown. Multiple wireless gateways are fixedly deployed in space, and the actual physical distances between them are known in advance (e.g., determined through precise measurements during deployment). Each wireless gateway is capable of receiving and transmitting wireless signals.

[0025] During the positioning process, the beacon anchor point periodically transmits wireless signals. Each wireless gateway receives the signals from the beacon anchor point and calculates its own "calculated distance" to the beacon anchor point based on RSSI. However, due to environmental interference, these calculated distances contain errors. Simultaneously, wireless gateways can also perform wireless ranging with each other to obtain the "calculated distance" between gateways. This invention is based on a key discovery: within a similar time and space range, the influence of the environment on wireless signal propagation has local consistency. Therefore, the technical concept of this invention includes the following: the error characteristics measured from the "gateway-to-gateway" link can be used to correct the measurement results of the "gateway-to-beacon anchor point" link. Since the actual distance between gateways is known, the error characteristics of wireless ranging on the gateway-to-gateway link under the current environment can be accurately calculated to correct the measurement results of the "gateway-to-beacon anchor point" link.

[0026] In a first embodiment of the present invention, the wireless distance correction method includes: The calculated distances between the device and other wireless gateways, as well as the calculated distances with the beacon anchor point, are obtained through wireless ranging. Obtain the actual distance between the device and other wireless gateways; The calculated distance of the beacon anchor point is corrected based on the calculated distance and the actual distance between it and other wireless gateways.

[0027] It is easy to understand that in the first embodiment of the present invention, the executing entity is a wireless gateway.

[0028] Step S10: Obtain the calculated distance between the device and other wireless gateways, as well as the calculated distance with the beacon anchor point, through wireless ranging.

[0029] It should be noted that this example uses a specific wireless gateway in the system (referred to as the "current gateway"). After the current gateway starts up, it performs two types of wireless signal measurements: 1. Inter-gateway ranging: The current gateway receives broadcast signals from one or more other wireless gateways and measures the Received Signal Strength Indicator (RSSI) value for each signal. Based on a preset wireless signal propagation model (such as the logarithmic path loss model), each RSSI value is converted into a distance value, i.e., the calculated distance from the current gateway to each other wireless gateway.

[0030] 2. Beacon anchor point distance measurement: The current gateway simultaneously receives broadcast signals from the beacon anchor point, measures its RSSI value, and calculates the distance to the beacon anchor point using the same signal propagation model.

[0031] The distances calculated above are based on raw observation data that includes environmental noise and interference.

[0032] The measurements of anchor points and gateways are highly synchronized or close in time, ensuring that they experience essentially the same environmental interference conditions, thus satisfying the correlation prerequisite for subsequent error propagation. Obtaining the calculated distance between gateways is equivalent to "testing" the ranging error caused by the environment, given the correct answer (actual distance), thereby quantifying the magnitude and nature of the error. This step enables each wireless gateway to sense not only the target (beacon anchor point) but also known, fixed-location reference nodes (other gateways) in the system. This provides multi-dimensional observational data for subsequent differential correction.

[0033] Step S20: Obtain the actual distance between the device and other wireless gateways.

[0034] It should be explained that the current gateway queries and reads the pre-calibrated actual physical distances from itself to the other wireless gateways mentioned above from its local memory, server, or connected central processing unit. These actual distances are fixed values ​​determined and entered into the system during the system deployment, installation, or initialization phase using high-precision measurement methods (such as laser rangefinders, total stations, or based on design drawings). When the actual physical distances between wireless gateways change, the actual distances between them obtained in this step should also be changed accordingly (the operator stores the modified actual distances of each wireless gateway in memory, server, or connected central processing unit after actually changing the distances between wireless gateways, which is consistent with real-world scenarios).

[0035] This step provides the basis for calculating the absolute error, allowing direct calculation of the absolute or relative error ratio of the ranging distance to each of the other gateways from the current gateway's perspective. The known actual distances between multiple gateways constitute a known spatial geometric network. The topology of this network is fixed, providing a stable reference frame for analyzing and correcting flowing, uncertain beacon anchor signals.

[0036] Step S30: Based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, correct the calculated distance of the beacon anchor point.

[0037] It should be explained that the current gateway uses the data obtained from steps S10 and S20 to correct the calculated distance of the beacon anchor point. This step realizes the inference and compensation from known errors to unknown errors. The logic is as follows: if the current gateway produces systematic deviations when measuring other gateways at known locations (for example, all calculated distances are 10% shorter than the actual distances), then it is reasonable to believe that when it measures beacon anchor points at unknown locations at the same time and location, it is also likely to be affected by the same proportion of systematic deviations.

[0038] By scaling the original calculated distance, the common attenuation or enhancement effects caused by local environments (such as metal cabinets or walls in specific corners) are effectively suppressed, resulting in a significant improvement in the accuracy of the corrected distance value when used as input for subsequent triangulation and other algorithms. Furthermore, even if some gateways fail to measure distance completely due to their own malfunctions or extreme local interference, other gateways can still independently correct the distance using their measurements with those of surrounding gateways, ensuring the system's continued operation and overall reliability even when some nodes are abnormal.

[0039] For example, a comprehensive correction factor can be calculated based on the measurement errors between gateways. For instance, the average or median of the error proportions of all other gateways communicating with the current gateway can be calculated as a representative correction factor for the local environment in which the current gateway is located. This calculated correction factor is then applied to the original calculated distance to the beacon anchor point. Through this operation, the original calculated distance of the interfered beacon anchor point is "pulled back" or "pushed out" to a value closer to the true distance (correcting the calculated distance of the beacon anchor point).

[0040] This invention discloses a wireless distance correction method, comprising: obtaining calculated distances between the beacon and other wireless gateways and the beacon anchor point through wireless ranging; obtaining the actual distances between the beacon and other wireless gateways; and correcting the calculated distances of the beacon anchor point based on the calculated distances between the beacon and other wireless gateways and the actual distances. This invention utilizes the error characteristics measured from the "gateway-to-gateway" link to correct the measurement results of the "gateway-to-beacon anchor point" link. Since the actual distances between gateways are known, the error characteristics of wireless ranging on the gateway-to-gateway link under the current environment can be accurately calculated, thereby correcting the measurement results of the "gateway-to-beacon anchor point" link and reducing the error in wireless distance calculation caused by environmental factors.

[0041] In one example, correcting the calculated distance of the beacon anchor point based on the calculated distance and the actual distance to other wireless gateways includes: Calculate the correction factor based on the calculated distance and actual distance between the device and other wireless gateways; The product of the correction factor and the calculated distance of the beacon anchor point is used as the corrected distance of the beacon anchor point.

[0042] It should be explained that this example quantifies the distance measurement error between gateways into a scalar correction factor, and applies this factor to the original calculated distance to the beacon anchor point through a simple multiplication operation. This method is computationally simple, easy to implement in wireless gateways or embedded devices with limited computing resources, and effectively compensates for systematic scaling errors caused by the environment.

[0043] Step S310: Calculate the correction factor based on the calculated distance and actual distance between the device and other wireless gateways.

[0044] It should be explained that an error scaling factor can be calculated for each other wireless gateway to characterize the degree of deviation of the wireless ranging model on the link from the current wireless gateway (the executing entity) to another wireless network.

[0045] Subsequently, the current gateway integrates all available error scaling factors to calculate a correction factor. The most direct and effective method is to calculate their arithmetic mean. Alternatively, depending on the actual situation, statistical methods such as weighted average, geometric mean, or median can be used to enhance robustness and eliminate interference from individual abnormal links.

[0046] This step, by fusing (e.g., averaging) the error factors of multiple reference links (gateway-to-gateway), smooths out random errors caused by transient interference (such as brief obstructions) on individual links, making the final correction factor more reflective of continuous, systematic environmental effects. It condenses multidimensional, discrete error observations into a single, representative correction parameter (correction factor). This abstracts the overall "distortion" level of the local environment in which the current gateway is located. It simplifies complex nonlinear interference effects such as multipath and obstruction into a linear scaling factor with respect to distance, greatly reducing the complexity of subsequent processing. Furthermore, it is particularly important to emphasize that the correction factor is a dynamic value that updates with environmental changes, making it a key variable for achieving adaptive calibration.

[0047] Step S320: The product of the correction factor and the calculated distance of the beacon anchor point is used as the corrected distance of the beacon anchor point.

[0048] This step is a direct application of the correction logic. It performs error compensation based on the reasonable assumption that "the environment has an approximately proportional impact on all wireless ranging links of the current gateway (including those to known gateways and unknown anchor points)." Multiplicative correction directly targets the overall drift of path loss model parameters (such as path loss exponent and reference signal strength) caused by the environment, effectively correcting common attenuation or enhancement caused by environmental materials, fixed obstacles, etc., significantly improving ranging accuracy. Furthermore, this step requires only one multiplication operation, placing extremely low demands on the gateway's processor, ensuring high feasibility and real-time performance on resource-constrained IoT devices.

[0049] This example transforms the complex problem of wireless environmental error compensation into an intuitive scaling factor calculation and multiplication operation, making the technical solution very easy to implement, deploy, and debug on various hardware platforms. It demonstrates good correction effects for signal attenuation caused by environmental factors with consistent characteristics (such as absorption by wall materials in specific areas).

[0050] In the second embodiment of the present invention, the step of obtaining the actual distance between the device and other wireless gateways includes: Based on the calculated distances to other wireless gateways and the calculated distances to beacon anchor points, the distance weighting coefficients for the corresponding wireless gateways are determined. The calculated distance of the beacon anchor point is corrected based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, as well as the distance weighting coefficients corresponding to the multiple wireless gateways.

[0051] It should be noted that in a system containing multiple wireless gateways, each gateway can provide a set of ranging error observations for its surrounding gateways. However, not all gateway observations are equally valuable for correcting the distance from the current gateway to the beacon anchor point. For example, the environmental interference reflected in the ranging error between a gateway far from the beacon anchor point and the current gateway may have a weak correlation with the environmental characteristics of the area where the beacon anchor point is located. This embodiment introduces an intelligent weighting mechanism, which allows the contribution of different gateways to be dynamically adjusted according to their relative geometric relationship with the beacon anchor point when using measurement errors among multiple gateways to correct the distance to the beacon anchor point, thereby achieving more accurate and robust data fusion and correction.

[0052] Step S40: Based on the calculated distances to other wireless gateways and the calculated distances to the beacon anchor points, determine the distance weighting coefficients for the corresponding wireless gateways.

[0053] Specifically, an effective determination logic is based on the following geometric insight: if the reference gateway and the beacon anchor are close to the current gateway, then the environmental interference experienced by the link from the reference gateway to the current gateway is likely to be more similar to the interference experienced by the link from the current gateway to the beacon anchor.

[0054] The determination of the distance weighting coefficient for the corresponding wireless gateway based on the calculated distances to other wireless gateways and the calculated distances to the beacon anchor points includes: Step S410: Based on a preset monotonically decreasing function, obtain the distance weights of other wireless gateways according to the calculated distances with other wireless gateways; It should be explained that this solution is based on a clear physical insight: in the propagation of wireless signals, the "patterns" of signal interference between nodes that are closer together are often more valuable for reference (they tend to be similar).

[0055] The wireless gateway currently performing the correction first obtains the calculated distance to each other wireless gateway; then, it substitutes the calculated distances of the other wireless gateways into a preset monotonically decreasing function to obtain the distance weights of the other wireless gateways.

[0056] This invention does not limit the type or form of the preset monotonically decreasing function. The preset monotonically decreasing function may include: exponential decay type, inverse proportional type, or Gaussian type, etc. The type and parameters of the preset monotonically decreasing function can be configured by the developers according to the network deployment density and environmental characteristics.

[0057] This step uses a monotonically decreasing function to ensure that reference gateways closer to the main gateway receive higher initial weights. Since nearby gateways are more likely to share the same local microenvironment as the main gateway, their measurement errors are more strongly correlated with the measurement errors from the main gateway to the beacon anchor point. Therefore, this weight allocation strategy can effectively filter and highlight the most relevant calibration reference information.

[0058] Step S420: Normalize the distance weights of the other wireless gateways to determine the distance weight coefficients of the other wireless gateways.

[0059] After obtaining the distance weights for all other wireless gateways, these weights need to be normalized to obtain the final distance weight coefficients that can be used for weighted summation. It's easy to understand that the purpose of normalization is to make the sum of all weight coefficients equal to 1, so that each coefficient clearly represents the proportion of the error information of the corresponding reference gateway in the final weighted correction factor.

[0060] Regardless of the range of absolute values ​​output by the initial weighting function, and regardless of the number of reference gateways involved in the calculation, the normalized weighting coefficient system is always standardized. This ensures that the weighted correction factors calculated by the main gateway at different times and based on different numbers of reference gateways have consistent scale meaning and comparability, avoiding the correction scale drift problem caused by the variable sum of weights.

[0061] Step S50: Based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, as well as the distance weighting coefficients corresponding to the multiple wireless gateways, correct the calculated distance of the beacon anchor point.

[0062] It is easy to understand that, for each reference gateway, an error scaling factor is calculated using its known actual distance and the measured calculated distance. This factor directly reflects the distance scaling caused by the environment on the link. After obtaining the distance weight coefficients corresponding to multiple wireless gateways, instead of taking a simple arithmetic average, a weighted average is performed to obtain an optimized correction factor, which focuses more on the error information of reference links that are close to the current link to be corrected in terms of calculated distance. Finally, the optimized correction factor is applied to the original calculated distance from the current gateway to the beacon anchor point to obtain the corrected distance.

[0063] In scenarios with high environmental heterogeneity (e.g., different areas within a factory have different degrees of occlusion), weighted fusion can automatically reduce the influence of reference data from areas with large environmental differences and strengthen the contribution of data from similar areas, thereby obtaining a correction factor that is more representative of the actual local environment of the beacon anchor point, which is more accurate than the unweighted averaging method.

[0064] In practical deployments, environmental interference in large spaces is often non-uniform. The weighting mechanism of this method enables it to adaptively address this non-uniformity, making it particularly suitable for complex indoor scenarios such as warehouses, factories, and large shopping malls, ensuring consistent positioning accuracy across the entire environment. Each gateway performs independent calibration based on localized weight calculations, forming a distributed, adaptive calibration network. This not only improves individual ranging accuracy but also enhances the overall resilience and reliability of the positioning system in the event of partial node failures or sudden environmental changes.

[0065] In one example, obtaining the actual distance to other wireless gateways further includes: Obtain the azimuth angle of the beacon anchor point and the azimuth angles of other wireless gateways; A wireless gateway is identified where the difference between its azimuth angle and the beacon anchor point's azimuth angle falls within a first angle range, and the difference between its calculated distance and the calculated distance to the beacon anchor point falls within a set distance range. The calculated distance to the beacon anchor point is then corrected using the calculated distance to the wireless gateway and the actual distance to the beacon anchor point. The absolute value of the difference between the angle within the first angle range and 180° is less than a preset angle value.

[0066] It's important to clarify that when using multiple gateways for self-calibration, not all communicable neighboring gateways are geometrically equally important. The core of this example lies in recognizing that selecting reference gateways that are roughly in the opposite direction (opposite) to the beacon anchor relative to the current gateway, and whose distance to the current gateway is close, provides the most geometrically advantageous error observations for correcting the distance to that beacon anchor. This "opposite and equidistant" reference gateway, together with the current gateway and the beacon anchor, forms the most stable geometric configuration, maximizing the correlation of error characteristics from the reference link to the target link and avoiding error amplification due to unfavorable geometric relationships.

[0067] Step S60: Obtain the azimuth angle of the beacon anchor point and the azimuth angles of other wireless gateways.

[0068] The wireless gateway currently performing the calibration needs to determine the following two azimuth angles: 1. Beacon anchor point azimuth, which is the direction of the beacon anchor point relative to the main gateway. Its acquisition methods include, but are not limited to: based on the signal angle of arrival (if the main gateway is equipped with a directional antenna array, the signal incident direction can be directly measured by processing the received beacon anchor point signal) and based on rough location and geometric calculations: if the approximate area or historical location of the beacon anchor point is known, combined with the fixed position of the main gateway itself, the relative azimuth can be estimated.

[0069] 2. Azimuth angles of other wireless gateways, i.e., the directions of other reference gateways relative to the main gateway. Since all gateway positions are fixed, their azimuth angles are usually pre-measured and stored system parameters. In systems where gateways support mutual AoA measurements, they can also be obtained in real time through inter-gateway communication. These azimuth angles should be defined in a unified reference system (e.g., with geographic north as 0°, increasing clockwise). This step introduces crucial two-dimensional spatial orientation information into the calibration process, elevating the system from simple one-dimensional distance measurement to two-dimensional spatial relationship analysis with orientation awareness.

[0070] Step 70: Determine a wireless gateway whose azimuth difference with the beacon anchor point azimuth is within a first angle range and whose calculated distance difference with the calculated distance of the beacon anchor point is within a set distance range, and use the calculated distance and actual distance of the wireless gateway to correct the calculated distance of the beacon anchor point; wherein, the absolute value of the difference between the angle and 180° within the first angle range is less than a preset angle value.

[0071] Specifically, a wireless gateway is defined as having a first angle interval where the difference between its azimuth and the beacon anchor's azimuth falls within a first angle interval, and a difference between its calculated distance and the calculated distance to the beacon anchor falls within a set distance interval. Within this first angle interval, the absolute value of the difference between the angle and 180° is less than a preset angle value. Meeting this condition means that the reference gateway and the beacon anchor are approximately located on opposite sides of the main gateway (the executing entity), with their directions being essentially opposite. The set distance interval and the preset angle value are specifically determined by the R&D personnel.

[0072] The near-opposite and equidistant geometric relationship ensures that the two wireless signal paths—reference gateway-main gateway and beacon anchor-main gateway—are spatially almost completely opposite and of equal length. Under this ideal condition, the environmental attenuation, reflection, and obstruction patterns experienced by the two paths are highly similar, especially the systematic errors caused by the main gateway's local RF environment (such as antenna characteristics and nearby fixed obstacles), which are almost identical. In multilateral positioning, if all reference points and the target point are located on the same side of the receiver, a poor geometric configuration is formed, leading to a significant amplification of ranging errors (i.e., a high geometric dilution of accuracy factor, GDOP). This method actively constructs a low-GDOP reference geometry for the main gateway by selecting "opposite" reference points. This not only improves the quality of current single-point distance correction but, more importantly, lays a robust geometric foundation for subsequent collaborative positioning across the entire network, reducing the sensitivity of the final positioning result to individual measurement errors from the source.

[0073] In real-world environments such as factories and warehouses, propagation conditions can vary significantly depending on the direction. This filtering mechanism automatically excludes gateways that have a very small angle (on the same side) with the beacon anchor point. These gateways' links may traverse completely different obstacles, and their error characteristics are not reliable. Simultaneously, distance filtering also excludes excessively distant gateways. This is equivalent to an intelligent, physically-based spatial filter, ensuring the high purity and consistency of the dataset used for correction, thus maintaining superior correction performance even in complex environments.

[0074] Finally, the calculated distance to the beacon anchor point is corrected using the calculated distance to the wireless gateway and the actual distance.

[0075] It should be noted that the correction factor calculated based on a highly correlated, high-quality reference set is minimally affected by transient anomalies or random fluctuations in individual gateways. Therefore, the corrected distance values ​​exhibit extremely low variance and excellent temporal stability, significantly reducing jitter in the positioning results.

[0076] Traditional methods passively accept data from all neighboring gateways. This method, however, proactively constructs an optimal local reference frame based on the real-time location of the beacon anchor point, dynamically constructing a set of "opposite and equidistant" gateways. This achieves intelligent, dynamic, and optimized calibration of the reference frame. Regardless of the beacon anchor point's location within the network or the symmetrical deployment of local gateways, this method automatically finds the best available combination of reference gateways. This significantly improves the accuracy consistency and reliability of the positioning system across all scenarios and time periods, making it particularly suitable for deployment in industrial positioning and navigation applications with stringent accuracy requirements.

[0077] The calculation of the distance between the wireless gateway and the beacon anchor point obtained through wireless ranging includes: Collect the RSSI values ​​of other wireless gateways and the RSSI values ​​of the beacon anchor point; Based on the RSSI values ​​of the other wireless gateways, the calculated distance to other wireless gateways is determined; The calculated distance of the beacon anchor point is determined based on its RSSI value.

[0078] It's easy to understand that the wireless receiving module of the main gateway currently performing the correction needs to listen to signals from two channels simultaneously: Inter-gateway signaling channel: Listens for and receives wireless signals (e.g., Bluetooth broadcast packets or Wi-Fi beacon frames in a specific format) periodically broadcast from other fixed wireless gateways in the system. For each successfully decoded signal packet from a gateway, its physical or link layer provides a Received Signal Strength Indicator (RSSI) value. This value is typically a negative dBm value (e.g., -65dBm), and the smaller the absolute value, the stronger the received signal.

[0079] Beacon Anchor Signal Channel: This channel listens for and receives wireless signals (e.g., Bluetooth broadcasts in iBeacon or Eddystone format) periodically emitted from the beacon anchor point to be located. Similarly, for each signal packet from the anchor point, its corresponding RSSI value is acquired. Acquisition is typically performed continuously or periodically to obtain a series of RSSI samples for subsequent processing.

[0080] RSSI values ​​comprehensively reflect all environmental factors such as path loss, shadowing fading, and multipath effects on the signal propagation path, and are the only original data source for subsequent correction algorithms to eliminate errors.

[0081] Subsequently, the RSSI values ​​collected from other gateways (which can be single values ​​or statistical values ​​over a period of time, such as the mean) are substituted into a preset wireless signal propagation model to calculate the distance estimate; the most commonly used model is the logarithmic distance path loss model.

[0082] Finally, the main gateway substitutes the RSSI values ​​collected from the beacon anchor points into the same signal propagation model to obtain the calculated distance to the beacon anchor points.

[0083] The same model and parameters are used for calculations on fixed gateways and moving anchors, ensuring the comparability between error observations (between gateways) and error quantities to be corrected (gateway-anchor point). That is, since both the distance between gateways and the distance between gateways and anchor points originate from the same measurement mechanism and calculation model, the error characteristics derived from the former can be effectively applied to the latter, ensuring the correct implementation of the core correction idea.

[0084] The process of collecting the RSSI values ​​of other wireless gateways and the RSSI values ​​of the beacon anchor points then includes: The RSSI values ​​of the other wireless gateways and the RSSI values ​​of the beacon anchors are filtered. Based on the filtered RSSI values ​​of the other wireless gateways, the calculated distance to other wireless gateways is determined. The calculated distance of the beacon anchor point is determined based on the filtered RSSI value of the beacon anchor point.

[0085] It's easy to understand that when the main gateway continuously collects RSSI values ​​from various reference gateways and beacon anchors, it maintains a time-series buffer for each signal source, storing multiple RSSI samples collected within a recent period (e.g., the past 2-5 seconds). Subsequently, the RSSI sequence corresponding to each signal source is independently filtered. Common filtering algorithms include moving average filtering, median filtering, Kalman filtering, and low-pass filtering, among others.

[0086] Sudden drops or rises in RSSI caused by human movement or momentary equipment occlusion are smoothed by filters or removed as outliers to prevent these transient phenomena from distorting long-term stable distance estimates. In environments with frequent movement of people and vehicles, the raw RSSI fluctuates dramatically. Filtering allows the system to "focus" on more meaningful systematic path losses caused by static or semi-static environments (such as walls and furniture), rather than transient dynamic disturbances.

[0087] Based on the filtered RSSI values ​​of the other wireless gateways, the calculated distances to the other wireless gateways are obtained. Similarly, based on the filtered RSSI values ​​of the beacon anchor point, the calculated distance to the beacon anchor point is determined. This allows for a more accurate reflection of systematic biases caused by the environment. By suppressing noise, the filtering process makes the calculated values ​​of both the inter-gateway distance (used as an error observation) and the gateway-anchor point distance (used as a correction target) more reliable and stable. This directly translates to a more stable correction factor, a smoother final positioning output, and a more professional and reliable overall system performance.

[0088] The present invention also proposes a wireless positioning system, in one example, wherein the wireless positioning correction method includes: Obtain the calculated distance between each wireless gateway, and the calculated distance between each wireless gateway and the beacon anchor point; Based on the calculated and actual distances between each wireless gateway, the calculated distances between each wireless gateway and the beacon anchor point are corrected. The location of the beacon anchor point is determined based on the corrected calculated distances of each wireless network to the beacon anchor point.

[0089] It should be noted that this example aggregates and merges the local distance correction results distributed across various wireless gateways, and finally calculates the precise location of the beacon anchor point through a multilateral positioning algorithm.

[0090] The aforementioned specification primarily focuses on how a single wireless gateway utilizes information from its neighboring gateways to correct its single-point distance observations to the beacon anchor point. This embodiment defines how the system collaboratively utilizes the corrected, high-precision distance observations from all participating wireless gateways to calculate the two-dimensional or three-dimensional coordinates of the beacon anchor point using geometric principles. The executing entity in this invention example is typically a central positioning server, an edge computing unit, or a gateway designated as the master node within the system.

[0091] When the system's central processing unit (e.g., the positioning server) initiates a round of positioning calculations, it first collects two types of distance observation data from all wireless gateways in the network: 1. Inter-gateway distance calculation matrix: Obtain the calculated distance between any two wireless gateways. This data can be proactively reported by each gateway (e.g., each gateway reports its calculated distance to all other gateways), or it can be obtained through direct communication between gateways. Since the locations of all gateways are fixed, the actual distances between them are known database information for the central processing unit.

[0092] 2. Calculated distance from each gateway to the beacon anchor point: Obtain the raw calculated distance from each wireless gateway to the beacon anchor point as measured and reported; this data constitutes the raw input dataset for this positioning calculation. Data reporting can be periodic or triggered by the appearance of the beacon anchor point.

[0093] Subsequently, the central processing unit uses the collected data to correct the original calculated distance from each wireless gateway to the beacon anchor point. The principle and method of correction are completely consistent with the scheme described in the aforementioned specification, except that the executing entity changes from a single gateway to the central unit. Having the central unit uniformly perform the correction ensures that all gateways use completely consistent correction algorithms and parameters, avoiding systemic deviations that may occur in distributed correction due to differences in node computing capabilities and algorithm implementations, thus guaranteeing the overall consistency and fairness of the corrected data.

[0094] Finally, after obtaining a high-precision corrected distance vector, the central processing unit uses a polygonal localization algorithm to solve for the coordinates of the beacon anchor point.

[0095] The present invention also proposes a wireless positioning system, including a beacon anchor point and multiple wireless gateways; The beacon anchor point is used to transmit wireless signals; The plurality of wireless gateways are used to emit wireless signals, collect wireless signals from other wireless gateways, and calculate the computational distance to other wireless gateways. The plurality of wireless gateways are also used to collect the wireless signal of the beacon anchor point, calculate the calculated distance to the beacon anchor point, and correct the calculated distance of the beacon anchor point based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, and determine the location of the beacon anchor point.

[0096] The specific steps of the wireless positioning correction method are as described in the above embodiments. Since this wireless positioning system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0097] The present invention also proposes a storage medium storing a wireless distance correction program, which, when executed by a processor, implements the steps of the wireless distance correction method.

[0098] The storage medium refers to any physical or logical entity that can store program instructions (code) and data and be read by a computer (microprocessor).

[0099] For example, semiconductor memories include read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (such as NOR Flash and NAND Flash).

[0100] Magnetic storage media: such as hard disks and magnetic tapes.

[0101] Optical storage media: such as CD-ROM and DVD-ROM.

[0102] The specific steps of the wireless positioning correction method are as described in the above embodiments. Since this storage medium adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0103] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A wireless distance correction method, characterized in that, A wireless gateway used in wireless positioning systems; The wireless positioning system includes: beacon anchor points and multiple wireless gateways; The wireless distance correction method includes: The calculated distances between the device and other wireless gateways, as well as the calculated distances with the beacon anchor point, are obtained through wireless ranging. Obtain the actual distance between the device and other wireless gateways; The calculated distance of the beacon anchor point is corrected based on the calculated distance and the actual distance between it and other wireless gateways.

2. The wireless distance correction method as described in claim 1, characterized in that, The process of correcting the calculated distance of the beacon anchor point based on the calculated distance and actual distance between it and other wireless gateways includes: Calculate the correction factor based on the calculated distance and actual distance between the device and other wireless gateways; The product of the correction factor and the calculated distance of the beacon anchor point is used as the corrected distance of the beacon anchor point.

3. The wireless distance correction method as described in claim 1, characterized in that, The process of obtaining the actual distance between the device and other wireless gateways includes: Based on the calculated distances to other wireless gateways and the calculated distances to beacon anchor points, the distance weighting coefficients for the corresponding wireless gateways are determined. The calculated distance of the beacon anchor point is corrected based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, as well as the distance weighting coefficients corresponding to the multiple wireless gateways.

4. The wireless distance correction method as described in claim 3, characterized in that, The determination of the distance weighting coefficient for the corresponding wireless gateway based on the calculated distances to other wireless gateways and the calculated distances to the beacon anchor points includes: Based on a preset monotonically decreasing function, the distance weights of other wireless gateways are obtained according to the calculated distances with other wireless gateways. The distance weights of the other wireless gateways are normalized to determine the distance weight coefficients of the other wireless gateways.

5. The wireless distance correction method as described in claim 3, characterized in that, The process of obtaining the actual distance between the device and other wireless gateways also includes: Obtain the azimuth angle of the beacon anchor point and the azimuth angles of other wireless gateways; A wireless gateway is identified where the difference between its azimuth angle and the beacon anchor point's azimuth angle falls within a first angle range, and the difference between its calculated distance and the calculated distance to the beacon anchor point falls within a set distance range. The calculated distance to the beacon anchor point is then corrected using the calculated distance to the wireless gateway and the actual distance to the beacon anchor point. The absolute value of the difference between the angle within the first angle range and 180° is less than a preset angle value.

6. The wireless distance correction method according to any one of claims 1 to 5, characterized in that, The calculation of the distance between the wireless gateway and the beacon anchor point obtained through wireless ranging includes: Collect the RSSI values ​​of other wireless gateways and the RSSI values ​​of the beacon anchor point; Based on the RSSI values ​​of the other wireless gateways, the calculated distance to other wireless gateways is determined; The calculated distance of the beacon anchor point is determined based on its RSSI value.

7. The wireless distance correction method as described in claim 6, characterized in that, The process of collecting the RSSI values ​​of other wireless gateways and the RSSI values ​​of the beacon anchor points then includes: The RSSI values ​​of the other wireless gateways and the RSSI values ​​of the beacon anchors are filtered. Based on the filtered RSSI values ​​of the other wireless gateways, the calculated distance to other wireless gateways is determined. The calculated distance of the beacon anchor point is determined based on the filtered RSSI value of the beacon anchor point.

8. A wireless positioning correction method, characterized in that, The wireless positioning correction method includes: Obtain the calculated distance between each wireless gateway, and the calculated distance between each wireless gateway and the beacon anchor point; Based on the calculated and actual distances between each wireless gateway, the calculated distances between each wireless gateway and the beacon anchor point are corrected. The location of the beacon anchor point is determined based on the corrected calculated distances of each wireless network to the beacon anchor point.

9. A wireless positioning system, characterized in that, Includes beacon anchors and multiple wireless gateways; The beacon anchor point is used to transmit wireless signals; The plurality of wireless gateways are used to emit wireless signals, collect wireless signals from other wireless gateways, and calculate the computational distance to other wireless gateways. The plurality of wireless gateways are also used to collect the wireless signal of the beacon anchor point, calculate the calculated distance to the beacon anchor point, and correct the calculated distance of the beacon anchor point based on the calculated distance and actual distance between the beacon anchor point and other wireless gateways, and determine the location of the beacon anchor point.

10. A storage medium, characterized in that, The device stores a wireless distance correction program, which, when executed by a processor, implements the steps of the wireless distance correction method as described in any one of claims 1 to 7, or the steps of the wireless positioning correction method as described in claim 8.

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