A method, device and system for positioning by combining Beidou navigation technology and internet of things

Abstract

The application relates to the field of wireless positioning technology, in particular to a Beidou navigation technology combined with an Internet of Things positioning method, device and system, which comprises the following steps: arranging a reference station network and selecting a target baseline group in the reference station network; determining the relative independence between each independent baseline in the target baseline group and other independent baselines; for each independent baseline in the target baseline group, correcting the initial double-difference observation equation corresponding to each independent baseline based on the relative independence to obtain a final double-difference observation equation after correction; generating a virtual reference station based on the final double-difference observation equation after correction; and jointly solving the flow station data received by a GNSS receiver through the virtual reference station to obtain a real-time dynamic differential positioning result. Since the final double-difference observation equation after correction is more accurate, the virtual reference station is more valuable, and finally the influence of signal propagation error can be reduced, and the accuracy of the real-time dynamic differential positioning result is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless positioning technology, in particular to a Beidou navigation technology combined with Internet of Things positioning method, device and system. BACKGROUND

[0002] One of the main applications of Beidou navigation technology is high-precision positioning, among which the differential positioning technology is a commonly used method to achieve high-precision positioning. The basic principle is to correct the errors caused by factors such as multipath effect and atmospheric interference through wireless communication between the reference station and the mobile terminal. The most commonly used differential positioning technology at present is RTK (Real Time Kinematic, Real-Time Kinematic Differential Positioning). RTK sends differential correction data from the reference station to the mobile terminal in real time to correct the GNSS (Global Navigation Satellite System) signal received by the mobile terminal, thereby achieving centimeter-level precision positioning. This positioning scheme can be applied to surveying and mapping, engineering construction, farmland management and other scenarios with high positioning accuracy requirements.

[0003] In related technologies, ionospheric errors are shared by multiple baselines, resulting in error propagation. When different baselines use shared ionospheric errors, the accuracy of the correction is reduced, resulting in a delay in the propagation of the ionosphere to the GNSS signal. In practical applications, a group of independent baselines can be selected to reduce the effects of tropospheric errors, path effect errors, satellite orbit errors and other error propagation effects, avoiding redundant information and mutual dependence between different baselines, thereby reducing the impact of errors on one baseline on other baselines. However, for a selected group of independent baselines, it is not possible to be completely independent. Due to the propagation of errors, the observation error of the double-difference observation equation of each independent baseline calculated subsequently will deviate, thereby significantly reducing the positioning accuracy. SUMMARY

[0004] In order to solve the technical problem that a selected group of independent baselines cannot be completely independent, due to the propagation of errors, the observation error of the double-difference observation equation of each independent baseline calculated subsequently will deviate, thereby significantly reducing the positioning accuracy, the purpose of the present application is to provide a Beidou navigation technology combined with Internet of Things positioning method, device and system, the technical solution adopted is as follows:

[0005] A Beidou navigation technology combined with Internet of Things positioning method, the method comprises:

[0006] Arranging a reference station network and selecting a target baseline group in the reference station network;

[0007] Determining the relative independence between each independent baseline and other independent baselines in the target baseline group;

[0008] For each independent baseline in the target baseline group, the initial double-difference observation equation corresponding to the relative independence is modified to obtain a final modified double-difference observation equation;

[0009] Based on the final modified double-difference observation equation, a virtual reference station is generated;

[0010] The flow station data received by the GNSS receiver is jointly solved through the virtual reference station to obtain a real-time dynamic differential positioning result.

[0011] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, a target baseline group is selected in the reference station network, comprising:

[0012] The direction dispersion degree and the spatial layout rationality corresponding to each baseline group in the reference station network are calculated;

[0013] Based on the direction dispersion degree and the spatial layout rationality corresponding to each baseline group, the selectability of each baseline group is calculated;

[0014] The baseline group with the highest selectability is selected as the target baseline group.

[0015] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, the direction dispersion degree corresponding to each baseline group in the reference station network is calculated, comprising:

[0016] For each baseline group in the reference station network, any two baselines in the baseline group are taken as a baseline pair to obtain a plurality of baseline pairs;

[0017] The angle difference between the two baselines in each baseline pair is calculated respectively;

[0018] The angle differences corresponding to all baseline pairs in the baseline group are summed to obtain the direction dispersion degree corresponding to each baseline group.

[0019] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, the spatial layout rationality corresponding to each baseline group in the reference station network is calculated, comprising:

[0020] The center coordinates and lengths corresponding to any two baselines in each baseline group in the target dimension are obtained respectively;

[0021] Based on the center coordinates corresponding to any two baselines in each baseline group in the target dimension, the distance between the two baselines is calculated;

[0022] Based on the lengths corresponding to any two baselines in each baseline group in the target dimension, the distance availability of the two baselines in the target dimension is calculated;

[0023] Calculate the spatial layout rationality degree corresponding to each baseline group based on the distance between any two baselines and the distance availability of the any two baselines in the target dimension.

[0024] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, the relative independence between each independent baseline in the target baseline group and other independent baselines is determined, including:

[0025] Calculate the independent contribution degree corresponding to each independent baseline in the target baseline group;

[0026] Based on the independent contribution degree corresponding to each independent baseline in the target baseline group, the relative independence between each independent baseline and other independent baselines is determined.

[0027] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, the independent contribution degree corresponding to each independent baseline in the target baseline group is calculated, including:

[0028] For each independent baseline in the target baseline group, the angle difference between the independent baseline and any other independent baseline is calculated respectively, and a plurality of angle differences corresponding to each independent baseline are obtained;

[0029] The average value of the plurality of angle differences corresponding to each independent baseline is obtained, and the independent contribution degree corresponding to each independent baseline is obtained.

[0030] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, for each independent baseline in the target baseline group, the initial double difference observation equation corresponding to each independent baseline is modified based on the relative independence, and the final modified double difference observation equation is obtained, including:

[0031] Taking any one independent baseline in the target baseline group as a target independent baseline, based on the relative independence of the target independent baseline with respect to any other independent baseline, the correction double difference observation equation of any other independent baseline to the target independent baseline is determined respectively;

[0032] The availability of each correction double difference observation equation is calculated respectively;

[0033] Based on the correction double difference observation equation and the availability, the final modified double difference observation equation corresponding to each independent baseline is established.

[0034] According to the positioning method of the Beidou navigation technology combined with the Internet of Things provided by the application, the availability of each correction double difference observation equation is calculated respectively, including:

[0035] determine observation error values of other independent baselines corresponding to the corrected double-difference observation equation respectively, and minimum and maximum observation error values of all independent baselines;

[0036] obtain a first difference value by subtracting the observation error value of the other independent baseline from the minimum observation error value;

[0037] obtain a second difference value by subtracting the minimum observation error value from the maximum observation error value;

[0038] obtain the availability of each corrected double-difference observation equation by dividing the first difference value by the second difference value.

[0039] In another aspect, the application also provides a positioning device of Beidou navigation technology combined with Internet of Things, which comprises:

[0040] a selection module, which arranges a reference station network and selects a target baseline group in the reference station network;

[0041] a determination module, which determines the relative independence between each independent baseline and other independent baselines in the target baseline group;

[0042] a correction module, which corrects an initial double-difference observation equation corresponding to each independent baseline in the target baseline group based on the relative independence to obtain a final double-difference observation equation after correction;

[0043] a generation module, which generates a virtual reference station based on the final double-difference observation equation after correction;

[0044] a positioning module, which jointly solves flow station data received by a GNSS receiver through the virtual reference station to obtain a real-time dynamic differential positioning result.

[0045] In another aspect, the application also provides a positioning system of Beidou navigation technology combined with Internet of Things, which comprises:

[0046] a GNSS receiver, which is used to receive flow station data;

[0047] a positioning server, which is used to arrange a reference station network, select a target baseline group in the reference station network, determine the relative independence between each independent baseline and other independent baselines in the target baseline group, correct an initial double-difference observation equation corresponding to each independent baseline in the target baseline group based on the relative independence to obtain a double-difference observation equation after correction, generate a virtual reference station based on the double-difference observation equation after correction, and jointly solve flow station data received by a GNSS receiver through the virtual reference station to obtain a real-time dynamic differential positioning result.

[0048] The application has the following beneficial effects:

[0049] By determining the relative independence between each independent baseline and other independent baseline in the target baseline group, for each independent baseline in the target baseline group, the initial double-difference observation equation corresponding to the relative independence is modified to obtain the modified final double-difference observation equation, and then the virtual reference station is generated based on the modified final double-difference observation equation, and finally the real-time dynamic differential positioning result is obtained by jointly solving the flow station data received by the GNSS receiver through the virtual reference station. Since the modified final double-difference observation equation is more accurate, the virtual reference station is more valuable, and finally the influence of signal propagation error can be reduced, and the accuracy of the real-time dynamic differential positioning result is improved. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0051] Figure 1 The method flowchart of the positioning method provided by one embodiment of the present application is shown in the figure.

[0052] Figure 2 The distribution diagram of at least part of the reference stations in the reference station network is shown in the figure.

[0053] Figure 3 The data interaction principle diagram of the GNSS receiver and the positioning server through the communication link is shown in the figure.

[0054] Figure 4 The structure diagram of the positioning device provided by one embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0055] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the following describes the positioning method, device and system provided by the present application in detail, as well as the specific implementation, structure, features and effects thereof, with reference to the drawings and preferred embodiments. Different "one embodiment" or "another embodiment" in the following description do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0056] 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 invention pertains.

[0057] The following description, in conjunction with the accompanying drawings, details a specific scheme for a positioning method, device, and system combining BeiDou navigation technology and the Internet of Things provided by this invention.

[0058] This embodiment relates to the field of wireless positioning, specifically applicable to real-time dynamic differential positioning scenarios. The process of real-time dynamic differential positioning requires the establishment of a positioning server, as follows: First, a triangulation network is constructed using multiple reference stations, forming a baseline between each pair of reference stations. Next, a set of independent baselines is selected from these baselines. The observations between the two reference stations and two satellites involved in each independent baseline are differentially analyzed to determine the double-difference observation equation for each independent baseline. Finally, the double-difference ambiguity of the known reference station is solved, and the double-difference ionospheric delay is extracted to generate a virtual reference station, thus completing the establishment of the positioning server.

[0059] However, it is impossible to achieve complete independence for a set of selected independent baselines. Therefore, due to the propagation of errors, the observation error of the double-difference observation equation for each independent baseline calculated subsequently may have a slight deviation, which in turn greatly reduces the accuracy of real-time dynamic differential positioning.

[0060] To address the above problems, embodiments of the present invention provide corresponding solutions.

[0061] Please see Figure 1 It illustrates a method flowchart of a positioning method combining BeiDou navigation technology and the Internet of Things according to an embodiment of the present invention, such as... Figure 1 As shown, the positioning method combining BeiDou navigation technology and the Internet of Things provided in this embodiment of the invention specifically includes:

[0062] Step 110: Set up the base station network and select the target baseline group in the base station network.

[0063] In practical applications, the location of the base station can be determined first. In this process, multiple geographically distributed points can be selected as base stations to ensure that the selected base stations are distributed over a wide area and to avoid any two base stations being too close or collinear, so as to reduce the geometric dependence of each base station.

[0064] After selecting a reference station, the position of each reference station can be accurately measured. Specifically, high-precision GNSS equipment or static measurement methods can be used to determine the three-dimensional coordinates (x, y, z) of each selected reference station.

[0065] After determining the position of the reference stations, the density of the reference stations can be further set to arrange the reference stations in a triangular network structure, that is, a triangle or polygon is formed between adjacent reference stations, so as to ensure that the reference station network covers a wide range and is effective. Figure 2 An exemplary reference station network is shown, which is built by five reference stations A, B, C, D and E, and the data emitted by the virtual reference station F determined thereby points to the data center P.

[0066] It can be understood that a baseline is formed between each pair of reference stations in the arranged reference station network, and a group of independent baselines is selected from all the baselines included in the reference station network as a target baseline group, that is, the target baseline group includes a plurality of independent baselines.

[0067] Step 120: Determine the relative independence between each independent baseline in the target baseline group and other independent baselines.

[0068] It can be understood that the relative independence between each independent baseline in the target baseline group and other independent baselines can reflect the angle dispersion of each independent baseline in the entire target baseline group, and the higher the relative independence, the better the angle dispersion.

[0069] Step 130: For each independent baseline in the target baseline group, correct the initial double-difference observation equation corresponding to the independent baseline based on the relative independence to obtain a final double-difference observation equation after correction.

[0070] Since the independent baselines in the target baseline group cannot be completely independent, and insufficient independence will cause error propagation, the observation error of the double-difference observation equation of each independent baseline obtained in subsequent calculation will have a slight deviation. Therefore, after determining the relative independence between each independent baseline in the target baseline group and other independent baselines, the observation error is corrected using the relative independence, so as to correct the initial double-difference observation equation.

[0071] Step 140: Generate a virtual reference station based on the final double-difference observation equation after correction.

[0072] In actual application, the double-difference ambiguity of the known reference station can be solved by the final double-difference observation equation after correction, the double-difference ionospheric delay can be extracted, and finally the virtual reference station is generated, so as to build a positioning server, and specifically, a server of an RTK system can be established.

[0073] Step 150: Jointly solve the flow station data received by the GNSS receiver through the virtual reference station to obtain a real-time dynamic differential positioning result.

[0074] In the real-time dynamic differential positioning link, after the GNSS receiver performs standard single point positioning on the received mobile station data, the positioning server built can utilize the communication link to jointly calculate with the virtual reference station to obtain the RTK fixed solution of the mobile station user, so as to realize the acquisition of the real-time dynamic differential positioning result.

[0075] In an embodiment, a target baseline group is selected in the reference station network, specifically including:

[0076] Firstly, the direction dispersion degree and the spatial layout rationality corresponding to each baseline group in the reference station network are calculated.

[0077] In a specific implementation, the direction dispersion degree corresponding to each baseline group in the reference station network is calculated, specifically including:

[0078] Firstly, for each baseline group in the reference station network, any two baselines in the baseline group are taken as a baseline pair to obtain a plurality of baseline pairs.

[0079] In actual application, the position coordinates of the two reference stations corresponding to each baseline are known. Taking baseline A as an example, the position coordinates of the two reference stations corresponding to baseline A are respectively and Then the vector corresponding to baseline A is:

[0080] (1) ;

[0081] In this embodiment, a group of independent baselines needs to be selected from all the baselines in the reference station network as the target baseline group. Generally, if there are N GNSS receivers for synchronous observation, N-1 independent baselines need to be determined, that is, each baseline group contains N-1 baselines. In GNSS positioning, the distributed baseline configuration helps to better determine the position of the GNSS receiver, avoids the problem of poor accuracy in a specific direction, and can more comprehensively cover different directions of satellite signals, enhance the anti-interference ability of the positioning system, and improve the positioning stability. Therefore, the more dispersed the N-1 independent baselines are, that is, the larger the angle difference between each two independent baselines is, the better.

[0082] Secondly, the angle difference between the two baselines in each baseline pair is calculated.

[0083] It can be understood that the angle difference between the two baselines can be obtained by calculating the angle cosine value between the two baselines.

[0084] Thirdly, the angle differences corresponding to all baseline pairs in the baseline group are summed to obtain the direction dispersion degree corresponding to each baseline group.

[0085] For all baselines in the reference station network, traverse N-1 baselines in each baseline group, and take the Qth baseline group as an example. The direction dispersion of the N-1 baselines can be calculated as follows:

[0086] (2);

[0087] wherein, represents the direction dispersion corresponding to the Qth baseline group, and A and B represent any two baselines in the Qth baseline group, that is, , represents the vector corresponding to baseline A in the Qth baseline group, represents the vector corresponding to baseline B in the Qth baseline group, represents the angle cosine value between baseline A and baseline B, that is, the angle difference.

[0088] In one specific implementation, the spatial layout rationality corresponding to each baseline group in the reference station network is calculated, specifically including:

[0089] First, the respective center coordinates and lengths of any two baselines in each baseline group under the target dimension are obtained.

[0090] It can be understood that since the independent baseline not only needs to ensure the direction dispersion, but also needs to cover the entire network range as widely as possible, in the x, y, and z dimensions, the greater the difference between the highest value and the lowest value of the baseline center coordinates of the target baseline group under each dimension, the better. However, not all baselines are useful for spatial positioning. Since the satellite signal is affected by factors such as atmosphere and ionosphere, it will increase with the increase of the length of the baseline, and a too long baseline will introduce more errors, so the smaller the length of each baseline, the more useful it is.

[0091] Taking baseline A as an example, the center point coordinates are:

[0092] (3);

[0093] wherein, represents the x-axis coordinate value of the center point of baseline A, represents the y-axis coordinate value of the center point of baseline A, represents the z-axis coordinate value of the center point of baseline A, 、 、 、 、 、 represents the coordinate values of the two end points of baseline A in the x, y, and z dimensions.

[0094] Secondly, the distance between any two baselines in each baseline group is calculated based on the respective center coordinates of any two baselines in the target dimension.

[0095] In practical applications, the absolute value of the difference between the respective center coordinates of any two baselines in the target dimension can be used as the distance between the two baselines.

[0096] Thirdly, the distance availability of any two baselines in the target dimension is calculated based on the respective lengths of any two baselines in the target dimension.

[0097] In practical applications, a hyperparameter can be pre-set, the length of any two baselines in the target dimension is summed with the hyperparameter, and the reciprocal of the summed value is obtained, which is the distance availability.

[0098] Fourthly, the spatial layout rationality corresponding to each baseline group is calculated based on the distance between any two baselines and the distance availability of any two baselines in the target dimension.

[0099] Then, the selectability of each baseline group is calculated based on the direction dispersion and the spatial layout rationality corresponding to each baseline group.

[0100] It can be understood that the selectability is mainly used to represent the possibility of each baseline group being selected as the target baseline group. The higher the selectability, the greater the possibility of the baseline group being selected as the target baseline group.

[0101] Finally, the baseline group with the highest selectability is selected as the target baseline group.

[0102] In this embodiment, the Qth baseline group is taken as an example. The selectability corresponding to the Qth baseline group can be represented as follows:

[0103] (4);

[0104] wherein, represents the selectability corresponding to the Qth baseline group, A and B represent any two baselines in the Qth baseline group, represents the maximum value, represents the center coordinate of baseline A in the mth dimension, represents the center coordinate of baseline B in the mth dimension, represents the distance between baseline A and baseline B in the mth dimension, represents the length of baseline A, represents the length of baseline B, represents a hyperparameter, represents the distance availability of baseline A and baseline B in the mth dimension, represents the maximum available distance of the Qth group of baseline groups in m dimensions, represents the spatial layout rationality of the Qth group of baseline groups, represents the direction dispersion degree corresponding to the Qth group of baseline groups.

[0105] By traversing all baseline groups, the selectability of each baseline group can be calculated, and the baseline group with the highest selectability is selected as the target baseline group.

[0106] In an embodiment, the relative independence between each independent baseline in the target baseline group and other independent baselines is determined, specifically including:

[0107] First, the independent contribution degree corresponding to each independent baseline in the target baseline group is calculated.

[0108] In a specific implementation, the independent contribution degree corresponding to each independent baseline in the target baseline group is calculated, specifically including:

[0109] First, for each independent baseline in the target baseline group, the angle difference between the independent baseline and any other independent baseline is calculated to obtain a plurality of angle differences corresponding to each independent baseline.

[0110] Second, the average value of the plurality of angle differences corresponding to each independent baseline is calculated to obtain the independent contribution degree corresponding to each independent baseline.

[0111] It can be understood that in the real-time dynamic differential positioning technology of Beidou navigation, the greater the angle difference between any independent baseline in the target baseline group and other independent baselines, the greater the independence of the position information provided, and thus the positioning system can better solve the position of the GNSS receiver, so that the error is not concentrated in a certain direction, and the influence of other independent baselines on the error accumulation of the current independent baseline can be reduced, and thus the independent contribution degree of the current independent baseline to the positioning result is greater.

[0112] In this embodiment, taking independent baseline A as an example, the independent contribution degree of independent baseline A can be calculated as follows:

[0113] (5);

[0114] wherein, represents the independent contribution degree of independent baseline A, represents that there are other independent baselines in the target baseline group except independent baseline A, represents the vector of independent baseline A, represents the vector of other independent baseline i, represents the angle cosine value (i.e. angle difference) between independent baseline A and other independent baseline i in the target baseline group, represents the average angle difference between the independent baseline A and other independent baselines in the target baseline group.

[0115] Similarly, the independent contribution of each independent baseline in the target baseline group can be determined.

[0116] Then, based on the independent contribution of each independent baseline in the target baseline group, the relative independence between each independent baseline and other independent baselines is determined.

[0117] In this embodiment, the relative independence of independent baseline A with respect to other independent baseline B is taken as an example. For the entire target baseline group, if the independent contribution of independent baseline A is higher than that of other independent baseline B, the angle dispersion of independent baseline A in the entire target baseline group is better. On the basis of the relative independent contribution, A and B are compared from the whole to the part. Generally, the larger the angle difference between the two is, the more independent they are. However, if the independent baselines with close distances are selected, they may be greatly affected by the same error sources, such as ionospheric delay and tropospheric delay. Independent baselines with long distances can effectively disperse these error sources and enhance the anti-interference ability and error correction ability of the positioning system. Therefore, two independent baselines with long distances should be selected as much as possible. It should be noted that the distance between two independent baselines is represented by the difference between the center coordinates of each dimension in this embodiment.

[0118] Accordingly, the relative independence of independent baseline A with respect to other independent baseline B can be represented as follows:

[0119] (6);

[0120] wherein, represents the relative independence of independent baseline A with respect to other independent baseline B, f represents the maximum-minimum normalization function, represents the center coordinate of independent baseline A in m dimensions, represents the center coordinate of other independent baseline B in m dimensions, represents the distance between independent baseline A and other independent baseline B in m dimensions, represents the overall distance between independent baseline A and other independent baseline B, represents the angle cosine value (i.e. angle difference) between independent baseline A and other independent baseline B, represents the independent contribution of independent baseline A, represents the independent contribution of other independent baseline B, represents the independent contribution of independent baseline A with respect to other independent baseline B.

[0121] Similarly, the relative independence of each independent baseline in the target baseline group with respect to another independent baseline can be determined.

[0122] In one embodiment, for each independent baseline in the target baseline group, the corresponding initial double-difference observation equation is modified based on the relative independence to obtain the modified final double-difference observation equation, specifically including:

[0123] First, any independent baseline in the target baseline group is taken as the target independent baseline. Based on the relative independence of the target independent baseline with respect to any other independent baseline, the corrected double-difference observation equation after correction by any other independent baseline to the target independent baseline is determined.

[0124] Understandably, for any independent baseline, the phase observations of the same satellite from two reference stations are first differentially analyzed to form the "inter-station difference". Then, the phase observations of the same satellite from another satellite are analyzed to form the difference between the two satellites, thus obtaining the initial double-difference observation equation.

[0125] In this embodiment, taking independent baseline A of the target baseline group as an example, it is assumed that the initial double-difference observation equation formed by independent baseline A under satellite a and satellite b is as follows:

[0126] (7);

[0127] in, This represents the initial double-difference observations of independent baseline A. This represents the true distance difference corresponding to independent baseline A. This represents the observation error of independent baseline A.

[0128] Similarly, the initial double-difference observation equations for other independent baselines i in the target baseline group, constructed using satellites a and b, are as follows:

[0129] (8);

[0130] in, This represents the initial double-difference observations of other independent baselines i. This represents the true distance difference corresponding to other independent baselines i. This represents the observation error of other independent baselines i.

[0131] After obtaining the initial double-difference observation equations, the initial double-difference observation equations of independent baseline A can be initially modified using other independent baselines i, because... Because independent baseline A has only [a certain number of unique baselines] compared to other independent baselines i The deviation value of the observation error caused by the relative independence. is the bias value of the observation error of the independent baseline A truly completely independently, according to which, the corrected double-difference observation equation of the other independent baseline i to the independent baseline A can be expressed as follows:

[0132] (9);

[0133] wherein, represents the corrected double-difference observation value of the independent baseline A, represents the true distance difference corresponding to the independent baseline A, represents the observation error of the independent baseline A, represents a hyperparameter, represents the observation error of the other independent baseline i, represents the relative independence of the independent baseline A relative to the other independent baseline i.

[0134] Similarly, the corrected double-difference observation equation of each other independent baseline to the independent baseline A can be obtained.

[0135] Then, the availability of each corrected double-difference observation equation is calculated respectively.

[0136] In one specific implementation, the availability of each corrected double-difference observation equation is calculated respectively, specifically including:

[0137] First, the observation error value of the other independent baseline corresponding to the corrected double-difference observation equation and the minimum and maximum observation error values of all independent baselines are determined respectively.

[0138] Second, the observation error value of the other independent baseline is subtracted from the minimum observation error value to obtain a first difference value.

[0139] Third, the maximum observation error value is subtracted from the minimum observation error value to obtain a second difference value.

[0140] Fourth, the first difference value is divided by the second difference value to obtain the availability of each corrected double-difference observation equation.

[0141] In actual application, the corrected double-difference observation equation of the independent baseline A obtained above is not necessarily available, assuming that the observation error of any other independent baseline in the initial double-difference observation equation is very small, which means that the difference between the independent baselines is accurately reflected in the observation under the given measurement conditions, that is, the higher the availability, the more applicable the correction. According to this, the availability of the corrected double-difference observation equation of the other independent baseline i to the independent baseline A can be expressed as follows:

[0142] (10);

[0143] wherein, an availability of the correction double-difference observation equation of the other independent baseline i to the independent baseline A, an observation error of the other independent baseline i, a minimum value of the observation error of all independent baselines, a maximum value of the observation error of all independent baselines, it is to be noted that the above calculation steps need to normalize each observation error in advance to ensure the accuracy of the calculated availability.

[0144] Similarly, the availability of the correction double-difference observation equation of each other independent baseline to the independent baseline A can be determined.

[0145] Finally, based on the correction double-difference observation equation and the availability, the final modified double-difference observation equation corresponding to each independent baseline is established.

[0146] After determining the correction double-difference observation equation and the availability of all other independent baselines to the independent baseline A, since the observation error contribution of the correction double-difference observation equation with higher availability is higher, accordingly, the final double-difference observation equation of the independent baseline A can be expressed as follows:

[0147] (11);

[0148] wherein, represents the final double-difference observation value of the independent baseline A, represents the real distance difference corresponding to the independent baseline A, represents the total number of independent baselines in the target baseline group, an availability of the correction double-difference observation equation of the other independent baseline i to the independent baseline A, an availability contribution degree of the correction double-difference observation equation of the other independent baseline i to the independent baseline A, represents the observation error of the independent baseline A, represents a hyperparameter, represents the observation error of the other independent baseline i, represents the relative independence of the independent baseline A relative to the other independent baseline i, represents the modified observation error of the other independent baseline i to the independent baseline A.

[0149] Similarly, the final double-difference observation equation of each independent baseline in the target baseline group can be determined.

[0150] In one specific implementation, based on the modified final double-difference observation equation, the process of generating a virtual reference station is as follows:

[0151] First, the double-difference ambiguity of the known reference station is solved by using the final double-difference observation equation.

[0152] It can be understood that in order to fix the whole phase ambiguity, the double difference ambiguity of the known reference station in the RTK system needs to be calculated by using the final double difference observation equation. In practical application, the ambiguity can be initially calculated as a floating point number by using the carrier phase observation value, and then the ambiguity is fixed. Specifically, the floating point ambiguity can be fixed to an integer value by using the existing algorithm (such as Lambda algorithm), and finally the correctness of the double difference ambiguity is ensured through residual analysis and verification test.

[0153] Then, the double difference ionospheric delay is extracted.

[0154] The double difference ionospheric delay can be eliminated by the double difference observation. Therefore, the double frequency observation is used first. Specifically, the ionospheric delay can be obtained by linear combination of the double frequency observation, and then time series analysis is performed to extract the stable ionospheric characteristics, so as to realize the extraction of the double difference ionospheric delay.

[0155] Finally, the virtual reference station is generated.

[0156] It can be understood that in order to reduce the error caused by the distance between the mobile terminal and the reference station, based on the position of the known reference station and the double difference observation, the virtual reference station closest to the user position can be generated by network RTK calculation, so as to realize the establishment of the positioning server.

[0157] In the real-time dynamic differential positioning link, the GNSS receiver performs standard single point positioning on the received flow station data, and then the virtual reference station in the positioning server can be combined with the GNSS receiver through the communication link to obtain the RTK fixed solution of the flow station user, so as to realize the real-time dynamic differential positioning.

[0158] Figure 3 The data interaction process of the GNSS receiver with the positioning server through the communication link is shown as follows: Figure 3As shown, on the side of the positioning server 210, the reference station 1, the reference station 2 and the reference station 3 can be preprocessed to construct a triangulation network to obtain a reference station network, and then a target baseline group is selected in the reference station network, the relative independence between each independent baseline in the target baseline group and other independent baselines is used to modify the corresponding initial double-difference observation equation to obtain a final double-difference observation equation, and then the double-difference ambiguity of the known reference station is solved, the double-difference ionospheric delay is extracted, and a virtual reference station is generated. After the GNSS receiver 220 receives the rover data, data preprocessing and local observation value extraction are performed, and then standard single-point positioning is performed through the PVT (Position Velocity Time, position-velocity-time) algorithm, and the coordinate parameters are sent to the virtual reference station in a specific data format through the communication link, and then the reference station observation value is extracted according to a specific protocol and sent to the GNSS receiver 220, and the RTK algorithm and the final double-difference observation equation are used to calculate the RTK floating solution, and the ambiguity fixing algorithm is used to obtain the RTK fixed solution of the rover user, so as to realize real-time dynamic differential positioning.

[0159] Based on the same overall inventive concept, the application also protects a Beidou navigation technology combined with Internet of Things positioning device and system. The Beidou navigation technology combined with Internet of Things positioning device and system provided by the application is described below. The Beidou navigation technology combined with Internet of Things positioning device and system described below can be mutually corresponding with the Beidou navigation technology combined with Internet of Things positioning method described above.

[0160] Please refer to Figure 4 which shows a Beidou navigation technology combined with Internet of Things positioning device provided by an embodiment of the application. The device specifically includes:

[0161] The selection module 310 arranges the reference station network and selects a target baseline group in the reference station network.

[0162] The determination module 320 determines the relative independence between each independent baseline in the target baseline group and other independent baselines.

[0163] The correction module 330 corrects the corresponding initial double-difference observation equation of each independent baseline in the target baseline group based on the relative independence to obtain a corrected final double-difference observation equation.

[0164] The generation module 340 generates a virtual reference station based on the corrected final double-difference observation equation.

[0165] The positioning module 350 jointly solves the rover data received by the GNSS receiver through the virtual reference station to obtain a real-time dynamic differential positioning result.

[0166] As to the apparatus in the above-mentioned embodiments, the specific manners in which the respective modules perform operations have been described in detail in the embodiments of the method, and thus will not be described in detail here.

[0167] In addition, the embodiment of the present application further provides a positioning system combining Beidou navigation technology and Internet of Things, which specifically comprises:

[0168] The GNSS receiver is configured to receive the rover data.

[0169] The positioning server is configured to arrange a reference station network, and select a target baseline group in the reference station network; determine the relative independence between each independent baseline in the target baseline group and other independent baselines; for each independent baseline in the target baseline group, correct the initial double-difference observation equation corresponding to the independent baseline based on the relative independence to obtain a corrected double-difference observation equation; generate a virtual reference station based on the corrected double-difference observation equation; and jointly solve the rover data received by the GNSS receiver through the virtual reference station to obtain a real-time dynamic differential positioning result.

[0170] It can be understood that the data interaction principle of the GNSS receiver and the positioning server in the embodiment can be referred to Figure 3 The GNSS receiver, the positioning server and the communication link involved in the whole interaction process can be regarded as an Internet of Things system, and the specific interaction process has been described in detail in the embodiments of the method, and thus will not be described here.

[0171] It should be noted that: the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0172] Each embodiment in the specification is described in a progressive manner, and the same and similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments.

Claims

1. A positioning method combining BeiDou navigation technology and the Internet of Things, characterized in that, The method includes: Establish a network of reference stations and select a target baseline group within the network of reference stations; Determine the relative independence of each independent baseline in the target baseline group from other independent baselines; For each independent baseline in the target baseline group, the corresponding initial double-difference observation equation is modified based on the relative independence to obtain the modified final double-difference observation equation. Based on the revised final double-difference observation equation, a virtual reference station is generated; The virtual reference station is used to jointly solve the rover data received by the GNSS receiver to obtain real-time dynamic differential positioning results; Selecting a target baseline group in the reference station network includes: Calculate the directional dispersion and spatial layout rationality of each baseline group in the reference station network; Based on the directional dispersion and spatial layout rationality of each baseline group, the selectability of each baseline group is calculated. The baseline group with the highest selectivity is selected as the target baseline group.

2. The positioning method combining BeiDou navigation technology and the Internet of Things according to claim 1, characterized in that, Calculating the directional dispersion of each baseline group in the reference station network includes: For each baseline group in the reference station network, any two baselines in the baseline group are taken as baseline pairs to obtain multiple baseline pairs; Calculate the angular difference between the two baselines in each baseline pair; The angular differences of all baseline pairs in the baseline group are summed to obtain the directional dispersion of each baseline group.

3. The positioning method combining BeiDou navigation technology and the Internet of Things according to claim 1, characterized in that, Calculating the spatial layout rationality of each baseline group in the reference station network includes: Obtain the center coordinates and length of any two baselines in each baseline group in the target dimension; Calculate the distance between any two baselines in each baseline group based on their respective center coordinates in the target dimension. Based on the lengths of any two baselines in each baseline group in the target dimension, calculate the distance availability of any two baselines in the target dimension. Based on the distance between any two baselines and the distance availability of any two baselines in the target dimension, the spatial layout rationality corresponding to each baseline group is calculated.

4. A positioning method combining BeiDou navigation technology and the Internet of Things according to claim 1, characterized in that, Determining the relative independence of each independent baseline in the target baseline group from other independent baselines includes: Calculate the independent contribution of each independent baseline in the target baseline group; Based on the independent contribution of each independent baseline in the target baseline group, the relative independence between each independent baseline and other independent baselines is determined.

5. A positioning method combining BeiDou navigation technology and the Internet of Things according to claim 4, characterized in that, Calculate the independent contribution of each independent baseline in the target baseline group, including: For each independent baseline in the target baseline group, calculate the angle difference between the independent baseline and any other independent baseline to obtain multiple angle differences corresponding to each independent baseline; The average of the multiple angle differences corresponding to each independent baseline is used to obtain the independent contribution of each independent baseline.

6. A positioning method combining BeiDou navigation technology and the Internet of Things according to claim 1, characterized in that, For each independent baseline in the target baseline group, the corresponding initial double-difference observation equation is modified based on the relative independence to obtain the modified final double-difference observation equation, including: Take any one independent baseline in the target baseline group as the target independent baseline, and based on the relative independence of the target independent baseline with respect to any other independent baseline, determine the corrected double-difference observation equation after any other independent baseline corrects for the target independent baseline. Calculate the availability of each of the corrected double-difference observation equations; Based on the corrected double-difference observation equation and the availability, the corrected final double-difference observation equation is established for each independent baseline.

7. A positioning method combining BeiDou navigation technology and the Internet of Things according to claim 6, characterized in that, Calculate the availability of each of the corrected double-difference observation equations, including: Determine the observation error values ​​of other independent baselines corresponding to the corrected double-difference observation equation, as well as the minimum and maximum observation errors of all independent baselines; The first difference is obtained by subtracting the observation error value of the other independent baselines from the minimum observation error value; The second difference is obtained by subtracting the maximum observation error from the minimum observation error. The availability of each of the corrected double-difference observation equations is obtained by dividing the first difference by the second difference.

8. A positioning device combining BeiDou navigation technology and the Internet of Things, characterized in that, The device includes: Select the module, arrange the base station network, and select the target baseline group in the base station network; The determination module determines the relative independence between each independent baseline in the target baseline group and other independent baselines; The correction module corrects the initial double-difference observation equations for each independent baseline in the target baseline group based on the relative independence, thereby obtaining the corrected final double-difference observation equations. The generation module generates a virtual reference station based on the corrected final double-difference observation equation; The positioning module performs joint calculations on the rover data received by the GNSS receiver using the virtual reference station to obtain real-time dynamic differential positioning results. Selecting a target baseline group in the reference station network includes: Calculate the directional dispersion and spatial layout rationality of each baseline group in the reference station network; Based on the directional dispersion and spatial layout rationality of each baseline group, the selectability of each baseline group is calculated. The baseline group with the highest selectivity is selected as the target baseline group.

9. A positioning system combining BeiDou navigation technology and the Internet of Things, characterized in that, The system includes: GNSS receiver, used to receive data from rover stations; A positioning server is used to deploy a network of reference stations and select a target baseline group within the network; determine the relative independence between each independent baseline in the target baseline group and other independent baselines; for each independent baseline in the target baseline group, modify the corresponding initial double-difference observation equation based on the relative independence to obtain a modified double-difference observation equation; generate a virtual reference station based on the modified double-difference observation equation; and perform joint calculations on rover data received by the GNSS receiver using the virtual reference station to obtain real-time dynamic differential positioning results. Selecting a target baseline group in the reference station network includes: Calculate the directional dispersion and spatial layout rationality of each baseline group in the reference station network; Based on the directional dispersion and spatial layout rationality of each baseline group, the selectability of each baseline group is calculated. The baseline group with the highest selectivity is selected as the target baseline group.

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