A real-time positioning system for geological survey personnel

Abstract

This application relates to the field of radio wave positioning technology, specifically to a real-time positioning system for geological exploration personnel. The system includes: a static reference construction module, used to set reference nodes on the centerline of the tunnel and generate virtual points on the left and right walls of each reference node based on the tunnel's designed width; a dynamic data acquisition module, used to acquire ultra-wideband ranging values, direct signal energy attenuation values, and step size increments; a position matching cost calculation module, used to calculate the ranging deviation by combining the virtual points, and after signal quality weighting, fuse the motion continuity cost to obtain the total position matching cost; and a positioning module, used to select the best estimated node based on the total cost to complete the positioning. This application solves the problem of positioning jumps and wall penetrations caused by wall contact and obstruction within the tunnel, improving the accuracy and reliability of positioning geological exploration personnel.

Description

Technical Field

[0001] This application relates to the field of radio wave positioning technology, specifically to a real-time positioning system for geological exploration personnel. Background Technology

[0002] In confined spaces such as geological exploration tunnels, tunnel excavations, and underground mines, where satellite positioning signals cannot provide coverage, the industry typically uses ultra-wideband (UWB) wireless ranging technology for personnel positioning. Existing positioning algorithms usually simplify the tunnel as a one-dimensional centerline and assume that the workers are always located on the central axis of the tunnel.

[0003] Existing positioning algorithms typically simplify the tunnel as a one-dimensional centerline, failing to distinguish between the geometrically reasonable extension caused by personnel walking close to the wall and the non-line-of-sight error caused by rock obstruction. This often leads to misinterpreting normal signals from walking close to the wall as abnormal drift, resulting in positioning results that jump left and right or even pass through walls. Furthermore, the multipath effect caused by rock masses within the tunnel further exacerbates distance fluctuations. In conclusion, using existing positioning algorithms to locate geological exploration personnel reduces the accuracy and reliability of their positioning. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide a real-time positioning system for geological exploration personnel, and the specific technical solution adopted is as follows: This application proposes a real-time positioning system for geological exploration personnel, the system comprising: The static benchmark construction module is used to set reference nodes on the centerline of the tunnel; based on the tunnel design width at each reference node, virtual points on the left and right walls of each reference node are generated along the tunnel width direction; The dynamic data acquisition module is used to enable geological exploration personnel to send ranging requests to each base station via the locator at any sampling time, obtain the ultra-wideband ranging value and direct signal energy attenuation value after each base station receives the request, as well as the step size increase of the geological exploration personnel. The location matching cost calculation module is used to determine the ranging deviation between each reference node and each base station based on the difference between the distance from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging value; calculate the signal quality confidence coefficient based on the direct signal energy attenuation value to perform weighted calculation of the ranging deviation, and obtain the weighted ranging deviation; aggregate the weighted ranging deviation between each reference node and all base stations, and combine it with the motion continuity cost constructed based on the step size increase to calculate the total location matching cost of each reference node; The positioning module is used to select the best estimated node from all reference nodes based on the total cost of location matching in order to locate the geological exploration personnel.

[0005] Preferably, the direct signal energy attenuation value is the absolute difference between the total received power and the first path power of each base station.

[0006] Preferably, the method for determining the ranging deviation between each reference node and each base station is as follows: Among the differences between the distances from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging values, the smallest difference is taken as the ranging deviation between each reference node and each base station.

[0007] Preferably, the signal quality confidence coefficient is the result obtained by substituting the direct signal energy attenuation value into a Gaussian exponential function.

[0008] Preferably, the expression for the weighted ranging deviation is: In the formula, This represents the weighted ranging deviation between the i-th reference node and the j-th base station at sampling time t; This represents the signal quality confidence coefficient of the j-th base station at sampling time t; This represents the ranging deviation between the i-th reference node and the j-th base station; This represents the preset non-line-of-sight penalty constant.

[0009] Preferably, the total location matching cost of each reference node is positively correlated with the weighted ranging deviation and motion continuity cost between each reference node and all base stations.

[0010] Preferably, the expression for the motion continuity cost is: In the formula, This represents the motion continuity cost of the i-th reference node at sampling time t; This represents the difference between the obtained sampling time t and the mileage value of the i-th reference node at the adjacent previous time. This represents the increase in the step size of the geological exploration personnel at sampling time t.

[0011] Preferably, the step of selecting the best estimated node from all reference nodes includes: At any sampling time, the reference node with the minimum total cost of position matching is selected from all reference nodes and is taken as the best estimated node at any sampling time.

[0012] Preferably, the method of locating geological exploration personnel includes: For the current sampling time, based on the best estimated node and its position matching total cost, a filtering algorithm is used to obtain the unique stable node from the best estimated node; The stable nodes are mapped onto a pre-built tunnel map, and the planar coordinates and mileage values ​​obtained from the tunnel map are used as the planar coordinates and mileage values ​​of the geological surveyors at the current sampling time.

[0013] Preferably, the process of obtaining the stable node is as follows: Extract the number of the best estimated node at all times within a preset time period before any sampling time, and filter the number. The best estimated node corresponding to the unique number obtained by filtering is recorded as a stable node.

[0014] This application has the following beneficial effects: This application firstly incorporates the geometric rationality of wall-hugging avoidance through ranging deviation, and achieves adaptive soft elimination of inferior signals obstructed by rock mass by utilizing signal quality confidence coefficient and weighted ranging deviation. Finally, it cleverly integrates spatial geometric observation and temporal motion physics laws into the total cost of location matching, thereby constructing a robust positioning evaluation system in complex and confined spaces that can simultaneously resist wall-hugging interference, resist non-line-of-sight errors, and eliminate instantaneous trajectory jumps. Furthermore, this application introduces a temporal median filtering mechanism to smooth and denoise the instantaneous best estimation node obtained from the global search, effectively eliminating outlier jumps caused by sudden electromagnetic interference. Finally, it maps the unique stable node to the tunnel map to output accurate planar coordinates and mileage values, thereby eliminating positioning jitter caused by single ranging calculations, ensuring the continuity and absolute engineering usability of the final position output for geological survey personnel, and improving the accuracy and reliability of positioning for geological survey personnel. Attached Figure Description

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A block diagram of a real-time positioning system for geological exploration personnel provided in one embodiment of this application; Figure 2 This is a schematic diagram of the total cost extraction process for location matching provided in one embodiment of this application. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a real-time positioning system for geological exploration personnel proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] The following description, in conjunction with the accompanying drawings, details a specific scheme for a real-time positioning system for geological exploration personnel provided in this application.

[0020] Please see Figure 1 The diagram illustrates a block diagram of a real-time positioning system for geological exploration personnel according to an embodiment of this application. The system includes: a static benchmark construction module 101, a dynamic data acquisition module 102, a location matching cost calculation module 103, and a positioning module 104.

[0021] The static benchmark construction module 101 is used to set reference nodes on the center line of the tunnel; based on the tunnel design width at each reference node, virtual points on the left and right walls of each reference node are generated along the tunnel width direction.

[0022] The main task of this embodiment is to establish a digital map model of the geological exploration tunnel to provide accurate geometric reference for subsequent personnel positioning. Unlike existing technologies that only use the tunnel centerline as a positioning reference, this embodiment constructs a model that includes reference nodes and virtual points on the right wall to support the correct identification of personnel walking along the wall.

[0023] P1: Set a reference node on the center line of the tunnel.

[0024] First, import the design drawings of the geological exploration tunnel. Since continuous curves cannot be directly processed by the computer, they need to be discretized into a series of ordered reference nodes.

[0025] Specifically, set a space away from the walking distance. In this embodiment, Set to 0.5 meters, along the centerline of the tunnel, every... Extract a sampling point from the distance, denoted as the reference node. For the i-th reference node, generate and store the following basic attributes: Node number : Uniquely identifies this reference node, with a value range of to ( (Total number of nodes).

[0026] Reference node coordinates : The planar position of the reference node in the geological engineering coordinate system.

[0027] Mileage The cumulative distance of the reference node along the starting point of the tunnel is used to indicate the depth of the tunnel.

[0028] Tangent vector direction : Tangent direction of the roadway at the reference node, used for subsequent calculation of the normal offset of the left and right walls.

[0029] P2: Based on the tunnel design width at each reference node, generate virtual points on the left and right walls of each reference node along the tunnel width direction.

[0030] Read the design cross-sectional width value at the i-th reference node. This value is usually given by geological design drawings. For regular tunnels, it can be regarded as a fixed constant (e.g., 4 meters), while for tunnels with variable cross-sections, it is a variable that varies with the mileage.

[0031] Furthermore, calculate the normal vector perpendicular to the tunnel direction. Based on center point coordinates Translate by a distance along the positive and negative directions of the normal vector, respectively. This yields two new coordinate points, denoted as virtual points on the left and right walls, respectively, where the direction of the normal vector is denoted as the tunnel width direction.

[0032] left wall virtual point coordinates The theoretical position of a representative walking close to the left side wall of the tunnel.

[0033] Right wall virtual point coordinates The theoretical position of a representative walking close to the right side wall of the tunnel.

[0034] The dynamic data acquisition module 102 is used to enable geological exploration personnel to send ranging requests to each base station via the locator at any sampling time, obtain the ultra-wideband ranging value and direct signal energy attenuation value after each base station receives the request, as well as the step size increase of the geological exploration personnel.

[0035] At sampling time t, geological survey personnel initiate ranging requests to all surrounding base stations using their worn locators. The size of the surrounding area depends on the line-of-sight propagation distance of the UWB signal, typically with a maximum single-sided communication distance of 100 to 200 meters. In this embodiment, the interval between adjacent sampling times is 1 second. For responding base station j, the following two sets of key data are collected: Ultra-wideband ranging values This is the straight-line distance from the locator to the base station, measured based on the Time-of-Flight (ToF) principle. In an ideal line-of-sight environment, this value should be equal to the actual physical distance; however, in an environment where rock formations obstruct the view, due to signal diffraction, this value is often greater than the actual distance.

[0036] Synchronously read the total received power from the base station (Including the superposition of energy from all reflection paths) and initial diameter power (Including only the energy of the first arrival path), based on these two power values, calculate the energy attenuation value of the direct signal. : In the formula, This represents the energy attenuation value of the direct signal from base station j at sampling time t; , These represent the total received power and the first path power of base station j at sampling time t, respectively.

[0037] The magnitude of the value directly reflects the degree of contamination of the ranging value: the greater the energy attenuation of the direct signal, the more severe the non-line-of-sight (NLOS) error, and the lower the reliability of the data in subsequent positioning.

[0038] To maintain positioning continuity in areas with unstable wireless signals, an inertial measurement unit (IMU) worn by the personnel is used for auxiliary calculations.

[0039] Acquisition Time Window The internal accelerometer data is used to identify a person's walking movements through a gait detection algorithm. Once a step is detected, the accelerometer data is accumulated. The step size within a time period, outputting the step size increment at sampling time t. This value represents the work of geological surveyors. The distance traveled along the inner lane.

[0040] It should be noted that this embodiment only uses the step size increment. The step size constraint is used to constrain the displacement range before and after the time interval, instead of using the heading angle data of the IMU. This is because strong magnetic interference (such as motor equipment) in geological tunnels often causes electronic compasses to fail, and the topology of the tunnel has already limited the direction of personnel movement. Therefore, the positioning requirements can be met by using only the step size constraint, while avoiding the error introduced by heading drift.

[0041] The location matching cost calculation module 103 is used to determine the ranging deviation between each reference node and each base station based on the difference between the distance from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging value; calculate the signal quality confidence coefficient based on the direct signal energy attenuation value to perform weighted calculation of the ranging deviation, and obtain the weighted ranging deviation; aggregate the weighted ranging deviation between each reference node and all base stations, and combine it with the motion continuity cost constructed based on the step size increase to calculate the total location matching cost of each reference node.

[0042] To address the issue of inflated ranging values ​​caused by people walking close to the walls in wide passageways, this embodiment determines the ranging deviation between each reference node and each base station based on the difference between the distance from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging value. Specifically: Among the differences between the distances from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging values, the smallest difference is taken as the ranging deviation between each reference node and each base station.

[0043] The ranging deviation can be understood as the minimum geometric error between the theoretical system distance and the actual distance measured by the base station, obtained by introducing a three-path competition mechanism (left, center, and right). It characterizes the spatial agreement between the currently assumed reference node (regardless of whether the geological survey personnel are at the center or against the wall) and the actual UWB ranging physical observation results, directly reflecting the probability that the personnel's actual location falls at that reference node. The calculation of this index is affected by the differences between the distances from the reference node and its left and right wall virtual points to each base station and the UWB ranging values. A larger difference means... A larger distance deviation indicates a significant discrepancy between the assumed geometric location of the reference node and the actual radio wave flight distance. This usually means that the geological survey personnel are not near the node, or that severe non-line-of-sight occlusion has occurred. The impact is that the corresponding reference node will be assigned a very high score in the subsequent global cost search and thus be removed as an anomaly. Conversely, a smaller difference indicates a smaller distance deviation, reflecting that the geological survey personnel are very likely actually present at the center or edge of the node. The impact is that the node will receive a lower base score and thus become a candidate point for location in the future.

[0044] Furthermore, the reliability of the data from each base station is quantitatively evaluated. Because rock masses in geological tunnels can cause abnormally high ranging values, directly using this data would lead to positioning errors. Therefore, this embodiment calculates the signal quality confidence coefficient based on the direct signal energy attenuation value, as follows: In this embodiment, the result obtained by substituting the direct signal energy attenuation value into the Gaussian exponential function is used as the signal quality confidence coefficient. For ease of understanding, the specific expression is given below: using the collected direct signal energy attenuation value Calculate each base station Signal quality confidence coefficient .

[0045] The specific calculation uses the following Gaussian decay function model: Confidence coefficient of signal quality of base station j at sampling time t The expression is: In the formula, This represents the energy attenuation value of the direct signal from base station j at sampling time t; This indicates the preset attenuation sensitivity parameter, which is used to adjust the sensitivity to signal quality. Its value range is generally [range missing]. to In this embodiment The value is set to 3dB. In practical applications, as other implementation methods, the implementer can also set it according to the specific situation. This embodiment does not impose special restrictions. For example, if the on-site environment is extremely harsh (frequent obstruction), the value can be appropriately increased. This allows for a more lenient tolerance for poor signal quality; if the on-site environment is favorable, the tolerance can be reduced. , to strictly eliminate interference signals; exp[ ] represents an exponential function with the natural constant as the base.

[0046] Based on the signal quality confidence coefficient, it can be understood that its essence is a probabilistic quantitative assessment of the reliability of a single UWB ranging data in the complex electromagnetic environment of the current tunnel. It is used to characterize the purity of the direct signal received by the base station, which is not affected by rock blockage or multipath interference. It directly reflects the weight ratio of the ranging value provided by the base station that should be trusted and adopted in the final positioning calculation. The calculation of the signal quality confidence coefficient is negatively affected by the energy attenuation value of the direct signal. The larger the energy attenuation value of the direct signal of the current base station, the closer the signal quality confidence coefficient is to 0. This reflects that there is rock blockage between the current base station and the locator, that is, the direct path energy is severely attenuated, and the receiver mainly relies on reflected waves. At this time, the ranging value contains a large non-line-of-sight error. Its impact is that the algorithm "softly shields" the current base station to prevent erroneous ranging data from deviating from the overall positioning result. Conversely, the smaller the energy attenuation value of the direct signal of the current base station, the closer the signal quality confidence coefficient is to 1. This reflects that the electromagnetic wave is in an ideal line-of-sight unobstructed propagation state, and the ranging value is highly accurate and reliable.

[0047] Furthermore, this embodiment calculates the ranging deviation using a weighted average based on the signal quality confidence coefficient, specifically: In this embodiment, the weighted ranging deviation between the i-th reference node and the j-th base station at any sampling time is... The expression is: In the formula, This represents the signal quality confidence coefficient of the j-th base station; This represents the ranging deviation between the i-th reference node and the j-th base station; This represents the preset non-line-of-sight penalty constant.

[0048] It should be noted that the preset non-line-of-sight penalty constant Q needs to be greater than the tunnel width, and its value range is generally 5 to 10 meters. In this embodiment, the preset non-line-of-sight penalty constant is 6 meters. In actual application, as other implementation methods, implementers can also set it according to specific circumstances. This embodiment does not impose any special restrictions.

[0049] The weighted ranging deviation can be understood as a composite penalty index that integrates the dual attributes of "spatial geometric fit" and "electromagnetic environment reliability." It characterizes the comprehensive matching cost of a reference node as the actual location of geological survey personnel after eliminating interference from unreliable base stations. It profoundly reflects the adaptive discrimination capability in wide tunnels, simultaneously considering both "reasonableness of wall-hugging avoidance" and "resistance to rock mass obstruction interference." The calculation of the weighted ranging deviation is positively influenced by the ranging deviation and the non-line-of-sight penalty constant, and negatively influenced by the signal quality confidence coefficient. The larger the ranging deviation, the greater the weighted ranging deviation. The degree increases positively, reflecting a mismatch in the geometric position of the corresponding reference node. When the signal quality confidence coefficient is smaller (severe obstruction), the weighted ranging deviation will jump directly to the penalty constant value, reflecting that the system directly cuts off the geometric association of the base station and forcibly reduces its weight. Its effect is to completely block the pollution of positioning results by inferior signals. Conversely, when the ranging deviation is smaller and the signal quality confidence coefficient is larger, the weighted ranging deviation will infinitely approach the extremely small pure geometric error value, reflecting that the corresponding reference node not only perfectly matches the measured data in spatial distance, but also that the base station providing the data is in a high-quality, unobstructed state.

[0050] Furthermore, this embodiment calculates the total position matching cost for each reference node by aggregating the weighted ranging deviation between each reference node and all base stations, and combining it with the motion continuity cost constructed based on the step size increase. Specifically: In this embodiment, the total location matching cost of each reference node is positively correlated with the ranging deviation and motion continuity cost between each reference node and all base stations.

[0051] It should be understood that a positive correlation means that the dependent variable increases as the independent variable increases, and the dependent variable decreases as the independent variable decreases. The specific relationship can be additive or multiplicative, etc., and is determined by the actual application. This application does not impose any special restrictions.

[0052] Preferably, as one implementation method, in this embodiment, the total cost of position matching of the i-th reference node at sampling time t is... The expression is: In the formula, This represents the mean of the weighted ranging deviation between the i-th reference node and all base stations at sampling time t; This represents the motion continuity cost of the i-th reference node at sampling time t; This represents the preset weight balance coefficient, which ranges from 0.5 to 1.0. In this embodiment, the preset weight balance coefficient is set to 0.8. In actual applications, as other implementation methods, implementers can also set it according to specific circumstances. This embodiment does not impose any special restrictions.

[0053] Preferably, the schematic diagram of the total cost extraction process for location matching provided in this embodiment is as follows: Figure 2 As shown.

[0054] It should be noted that the process of constructing the motion continuity cost is as follows: the motion continuity cost of the i-th reference node at sampling time t. The expression is: In the formula, This represents the difference between the obtained sampling time t and the mileage value of the i-th reference node at the adjacent previous time. This represents the increase in the step size of the geological exploration personnel at sampling time t.

[0055] It should be noted that in this embodiment, the absolute difference between the sampling time t and the mileage value of the i-th reference node at the adjacent previous time is taken as the difference between the sampling time t and the mileage value of the i-th reference node at the adjacent previous time.

[0056] Specifically, the total cost of position matching for each reference node at the first sampling time is numerically equal to the sum of the ranging deviations between each reference node and all base stations at the first sampling time.

[0057] Based on the total cost of location matching, it can be understood that it is essentially an ultimate scoring index that integrates the spatial geometric observations of multiple base stations across the entire map with the physical laws of personnel movement in the temporal domain. It is used to characterize the comprehensive probability that a discrete reference node in the alleyway map becomes the actual standing position of a person at the current sampling moment. It profoundly reflects the decision-making ability to make a globally optimal trade-off between "instantaneous radio electromagnetic wave ranging evidence" and "historical continuous walking inertia" in complex and confined spaces. The calculation of the total cost of location matching is positively influenced by both the weighted ranging deviation of multiple base stations and the cost of motion continuity, as well as the adjustment of the weight balance coefficient. The larger the sum of the weighted ranging weights, the greater the deviation or occlusion penalty of most base station rangings, and the greater the motion continuity... The greater the continuity cost, that is, when the distance of the current assumed node from the previous position is much greater than the step increment calculated by the inertial sensor, the total cost of position matching increases significantly. This reflects that the corresponding reference node is seriously out of sync with the measured electromagnetic environment in terms of spatial geometry, which will cause the corresponding node to be eliminated in the global search. Conversely, when the sum of the weighted ranging weights is smaller and the motion continuity cost is smaller, the total cost of position matching converges to close to zero. This reflects that the corresponding reference node can not only perfectly explain the ranging feedback of all base stations in three-dimensional space, but also closely follow the historical trajectory of the previous second and conform to the current step span in time axis, thereby increasing the probability that the corresponding reference node will be selected as a node for locating geological exploration personnel.

[0058] Thus, this embodiment achieves the geometric rationality of wall-hugging avoidance by incorporating the ranging deviation, and realizes the adaptive soft elimination of inferior signals obstructed by rock mass by utilizing the signal quality confidence coefficient and weighted ranging deviation. Finally, it cleverly integrates spatial geometric observation and temporal motion physics laws into the total cost of position matching, thereby constructing a robust positioning evaluation system in complex and confined space that can simultaneously resist wall-hugging interference, resist non-line-of-sight errors, and eliminate instantaneous trajectory jumps.

[0059] The positioning module 104 is used to select the best estimated node from all reference nodes based on the total cost of location matching in order to locate the geological exploration personnel.

[0060] For the current sampling time, based on the best estimated node and its total location matching cost, a filtering algorithm is used to obtain a unique stable node from the best estimated nodes. Specifically: At any sampling time, the reference node with the minimum total cost of position matching is selected from all reference nodes and is taken as the best estimated node at any sampling time. Furthermore, the numbers of the best estimated nodes at all times within a preset time period before any sampling time are extracted, and the numbers are filtered. The best estimated node corresponding to the unique number obtained by filtering is recorded as a stable node. In this embodiment, the median filtering algorithm is used to filter the numbers. For example, the result of the best estimated nodes in the preset time period before the current time being numbered in ascending order of position matching total cost is [4998, 4999, 5000, 5500, 5001]. The principle of median filtering is to remove the outlier "5500" and take the best estimated node corresponding to the middle number, i.e., 4999, as a stable node. If the length of the number sequence is odd, the best estimated node corresponding to the middle number is selected as a stable node. If the length of the number sequence is even, the best estimated node with a number value equal to half the sequence length is selected as a stable node.

[0061] To further clarify, the process of extracting the optimal estimated node number is as follows: During the static benchmark construction phase, all discrete reference nodes are sequentially numbered sequentially according to the direction of road extension; at any sampling moment of real-time positioning, after traversing all reference nodes and calculating their respective total location matching costs, the sequential number pre-bound to the reference node with the smallest total location matching cost is directly extracted, that is, the unique sequence number of the reference node corresponding to the smallest total cost in the map topology sequence is used as the number of the optimal estimated node at the current sampling moment.

[0062] The preset time period is set manually. In this embodiment, the preset time period is 5 seconds. In actual application, as other implementation methods, the implementer can also set it according to the specific situation. This embodiment does not impose any special restrictions.

[0063] Furthermore, the stable nodes are mapped to the tunnel map pre-built in the static benchmark construction module 101, and the planar coordinates and mileage values ​​obtained in the tunnel map are used as the planar coordinates and mileage values ​​of the geological survey personnel at the current sampling time.

[0064] Thus, this embodiment introduces a time-domain median filtering mechanism to smooth and denoise the instantaneous best estimated node obtained from the global search, effectively eliminating outlier jumps caused by sudden electromagnetic interference. Finally, it maps the unique stable node to the tunnel map to output accurate planar coordinates and mileage values, thereby eliminating the positioning jitter caused by single ranging calculations, ensuring the continuity and absolute engineering usability of the final position output of geological survey personnel, and improving the accuracy and reliability of positioning for geological survey personnel.

[0065] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0066] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0067] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A real-time positioning system for geological survey personnel, characterized in that, The system includes: The static benchmark construction module is used to set reference nodes on the centerline of the tunnel; based on the tunnel design width at each reference node, virtual points on the left and right walls of each reference node are generated along the tunnel width direction; The dynamic data acquisition module is used to enable geological exploration personnel to send ranging requests to each base station via the locator at any sampling time, obtain the ultra-wideband ranging value and direct signal energy attenuation value after each base station receives the request, as well as the step size increase of the geological exploration personnel. The location matching cost calculation module is used to determine the ranging deviation between each reference node and each base station based on the difference between the distance from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging value; calculate the signal quality confidence coefficient based on the direct signal energy attenuation value to perform weighted calculation of the ranging deviation, and obtain the weighted ranging deviation; aggregate the weighted ranging deviation between each reference node and all base stations, and combine it with the motion continuity cost constructed based on the step size increase to calculate the total location matching cost of each reference node; The positioning module is used to select the best estimated node from all reference nodes based on the total cost of location matching in order to locate the geological exploration personnel.

2. The real-time positioning system for geological survey personnel according to claim 1, characterized in that, The direct signal energy attenuation value is the absolute difference between the total received power and the initial path power of each base station.

3. The real-time positioning system for geological exploration personnel according to claim 1, characterized in that, The method for determining the ranging deviation between each reference node and each base station is as follows: Among the differences between the distances from each reference node and its left and right wall virtual points to each base station and the ultra-wideband ranging values, the smallest difference is taken as the ranging deviation between each reference node and each base station.

4. The real-time positioning system for geological exploration personnel according to claim 1, characterized in that, The signal quality confidence coefficient is the result obtained by substituting the direct signal energy attenuation value into the Gaussian exponential function.

5. A real-time positioning system for geological exploration personnel according to claim 1, characterized in that, The expression for the weighted ranging deviation is: In the formula, This represents the weighted ranging deviation between the i-th reference node and the j-th base station at sampling time t; This represents the signal quality confidence coefficient of the j-th base station at sampling time t; This represents the ranging deviation between the i-th reference node and the j-th base station; This represents the preset non-line-of-sight penalty constant.

6. A real-time positioning system for geological exploration personnel according to claim 1, characterized in that, The total cost of position matching for each reference node is positively correlated with the weighted ranging deviation and motion continuity cost between each reference node and all base stations.

7. A real-time positioning system for geological exploration personnel according to claim 6, characterized in that, The expression for the motion continuity cost is: In the formula, This represents the motion continuity cost of the i-th reference node at sampling time t; This represents the difference between the obtained sampling time t and the mileage value of the i-th reference node at the adjacent previous time. This represents the increase in the step size of the geological exploration personnel at sampling time t.

8. A real-time positioning system for geological exploration personnel according to claim 1, characterized in that, The step of selecting the best estimated node from all reference nodes includes: At any sampling time, the reference node with the minimum total cost of position matching is selected from all reference nodes and is taken as the best estimated node at any sampling time.

9. A real-time positioning system for geological exploration personnel according to claim 1, characterized in that, The location of geological exploration personnel includes: For the current sampling time, based on the best estimated node and its position matching total cost, a filtering algorithm is used to obtain the unique stable node from the best estimated node; The stable nodes are mapped onto a pre-built tunnel map, and the planar coordinates and mileage values ​​obtained from the tunnel map are used as the planar coordinates and mileage values ​​of the geological surveyors at the current sampling time.

10. A real-time positioning system for geological exploration personnel according to claim 9, characterized in that, The process of obtaining the stable node is as follows: Extract the number of the best estimated node at all times within a preset time period before any sampling time, and filter the number. The best estimated node corresponding to the unique number obtained by filtering is recorded as a stable node.

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