VRS switching method and device and storage medium

Abstract

The invention provides a VRS switching method and device and a storage medium, and the method comprises the steps: receiving a general position reported by a terminal, the general position being obtained by the terminal through RTK positioning based on the difference data of a nearby VRS, and the terminal generating a filtering calculation result in the RTK positioning process; when it is determined that the terminal needs to switch the VRS and the main reference station needs to be switched based on the approximate position, calculating ambiguity difference values of satellites before and after the main reference station is switched, and recording the ambiguity difference values as ambiguity reference change values; generating a first message containing the ambiguity reference change value; and broadcasting the first telegraph text and the differential data of the new VRS to the terminal, and when the terminal receives the first telegraph text, carrying out RTK positioning by using the old filtering calculation result based on the ambiguity reference change value and the differential data of the new VRS. According to the invention, the terminal can meet the requirement of continuous high-precision positioning when VRS switching occurs in a large-range motion scene.

Description

Technical Field

[0001] The present application relates to the field of space geodetic measurement technology, and in particular to a VRS switching method, device and storage medium. Background Art

[0002] When the Global Navigation Satellite System (GNSS) Continuously Operating Reference Stations (CORS) provides network RTK (Real-Time Kinematic) services, one of the most commonly used methods is to use the Virtual Reference Station (VRS) method to broadcast differential corrections to provide positioning for terminals.

[0003] However, the VRS method is mainly aimed at static and low-speed dynamic mapping scenarios. Therefore, when the terminal is in a large-scale motion, there is a problem of switching from one VRS to another. When the VRS is switched, the terminal may face the problem of reinitializing and fixing the ambiguity caused by using the differential data of different VRS for RTK positioning, which may affect the terminal's operating accuracy and efficiency in the process of switching VRS and reinitializing the ambiguity. Moreover, this phenomenon occurs more and more frequently in current scenarios such as high-precision vehicle-mounted navigation and high-precision positioning of drones.

[0004] Therefore, there is an urgent need to address the need for continuous high-precision positioning when VRS switching occurs in large-scale motion scenarios. Summary of the invention

[0005] The embodiment of the present application provides a VRS switching method, device and storage medium to solve the problems existing in the related technology. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present application provides a VRS switching method, including:

[0007] Receiving an approximate position reported by a terminal, wherein the approximate position is obtained by performing RTK positioning of the terminal based on differential data of a nearby VRS, wherein the terminal generates a filtering solution result during the RTK positioning process;

[0008] When it is determined based on the approximate position that the terminal needs to switch VRS and needs to switch the main reference station, the ambiguity difference of each satellite before and after switching the main reference station is calculated and recorded as the ambiguity reference change value, and the main reference station is the reference station used to generate the differential data of the VRS;

[0009] generating a first electronic message including the ambiguity reference change value;

[0010] The differential data of the first message and the new VRS is broadcasted to the terminal, and when the terminal receives the first message, the terminal uses the old filtering solution result to perform RTK positioning based on the differential data of the ambiguity reference change value and the new VRS.

[0011] In one embodiment, the method further comprises:

[0012] When it is determined based on the approximate position that the terminal needs to switch the VRS and does not need to switch the primary reference station, generating a second message indicating a change in the ambiguity-free reference of each satellite;

[0013] The second message and the differential data of the new VRS are broadcasted to the terminal. When the terminal receives the second message, it determines that there is no ambiguity baseline change for each satellite, and directly uses the old filtering solution result based on the differential data of the new VRS for RTK positioning.

[0014] In one implementation, calculating the ambiguity difference of each satellite before and after switching the primary reference station includes:

[0015] Obtain the baseline solution results between each reference station;

[0016] Based on the baseline solution result and the specified double difference model, the ambiguity difference of each satellite before and after switching the main reference station is calculated by filtering and fixing the ambiguity.

[0017] In one embodiment, the specified double difference model is expressed as:

[0018]

[0019] in, represents the double difference sign between satellite pq and receiver uv; P and L represent the pseudorange observation value and carrier phase observation value at the corresponding frequency j of satellite s and receiver r, respectively; E(*) represents the expectation operator; ρ is the distance between the satellite and the receiver; λ is the wavelength; N is the integer ambiguity, Z is the zenith wet tropospheric delay, and M is the mapping function from the zenith direction to the oblique direction; μ j is the frequency-dependent scaling factor from frequency 1 to frequency j; is the remaining ionospheric residual.

[0020] In one implementation, generating a first message including the ambiguity reference change value includes:

[0021] Generate the first telegram using a custom telegram format;

[0022] The custom message format includes the format fields of synchronization word, message type, message length, main reference station switching flag, reference station ID before switching, reference station ID after switching, satellite ambiguity change data and CRC check code, and the satellite ambiguity change data includes satellite PRN code, L1 frequency ambiguity change and L2 frequency ambiguity change.

[0023] In a second aspect, the embodiment of the present application further provides another VRS switching method, including:

[0024] Perform RTK positioning based on the differential data of nearby VRS to obtain a rough position, and report the rough position to the server. In the process of RTK positioning, a filtering solution result is generated;

[0025] When receiving the first message including the ambiguity reference change value and the differential data of the new VRS broadcasted by the server, the old filtering solution result is used for RTK positioning based on the differential data of the ambiguity reference change value and the new VRS;

[0026] Among them, the ambiguity baseline change value is obtained by calculating and recording the ambiguity difference of each satellite before and after switching the main reference station when the server determines that the terminal needs to switch VRS and needs to switch the main reference station based on the approximate position. The main reference station is the reference station used to generate differential data of VRS.

[0027] In one embodiment, the method further comprises:

[0028] When receiving the second message broadcast by the server indicating that there is no ambiguity reference change for each satellite and the differential data of the new VRS, it is determined that there is no ambiguity reference change for each satellite, and RTK positioning is performed directly based on the differential data of the new VRS using the old filtering solution result. The second message is generated when the server determines that the terminal needs to switch VRS based on the approximate position and does not need to switch the main reference station.

[0029] In one embodiment, performing RTK positioning based on the ambiguity reference change value and the differential data of the new VRS using the old filtering solution result includes:

[0030] The ambiguity baseline change value is added to the integer ambiguity of each satellite included in the old filtering solution result, and the remaining satellite ambiguity information not included in the old filtering solution result is reset with a cycle jump, and then the differential data of the new VRS is used for RTK positioning.

[0031] In a third aspect, an embodiment of the present application further provides a VRS switching device, comprising: a memory and a processor, wherein the memory stores instructions, and the instructions are loaded and executed by the processor to implement the method in any one of the embodiments of the first aspect above, or to implement the method in any one of the embodiments of the second aspect above, wherein the memory and the processor communicate with each other via an internal connection path.

[0032] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored. When the computer program runs on a computer, the method in any one of the above-mentioned embodiments is implemented.

[0033] The advantages or beneficial effects of the above technical solution include at least:

[0034] (I) Small amount of data transmission: Compared with the above-mentioned related technologies, when VRS switching may be required, the server needs to broadcast the differential data of the old VRS and the differential data of the new VRS to the terminal at the same time, and the terminal uses these two differential data for RTK positioning at the same time. In this application, the server only needs to broadcast the corresponding telegram of the differential data of the new VRS to the terminal. In terms of data volume, the data volume of the telegram is significantly smaller than that of the differential data of the VRS. That is, this application can significantly reduce the amount of data transmission.

[0035] (II) The terminal has a light computing burden: Compared with the above-mentioned related technologies, when VRS switching may be required, the terminal needs to simultaneously receive the differential data of two VRSs, and the terminal needs to use the differential data of the two VRSs to perform two RTK positionings, the present application only requires the terminal to receive the differential data of the new VRS, and only requires the terminal to adjust some of the parameters to be estimated before the switching according to the received ambiguity reference change, that is, the terminal only needs to use the same amount of data and computing as when the VRS is not switched for RTK positioning, and can continuously achieve high-precision operations within a larger CORS range. That is, the present application can significantly reduce the computing burden of the terminal.

[0036] That is, the present application reduces the amount of data transmission between the server and the terminal and alleviates the computing burden of the terminal, so that the terminal can meet the continuous high-precision positioning requirements when VRS switching occurs in large-scale motion scenarios.

[0037] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0039] Figure 1 A flowchart of a VRS switching method provided in an embodiment of the present application;

[0040] Figure 2 An example diagram of a Delaunay triangle network provided in an embodiment of the present application;

[0041] Figure 3 An example diagram of a master reference station for switching VRS and generating differential data of VRS provided in an embodiment of the present application;

[0042] Figure 4 An example diagram of a master reference station for switching VRS but not for generating differential data of VRS provided in an embodiment of the present application;

[0043] Figure 5 A flowchart of another VRS switching method provided in an embodiment of the present application;

[0044] Figure 6 A structural block diagram of a VRS switching device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0046] In the related technology, the server predicts that the RTK user may need to switch to VRS, and broadcasts the differential data of the next VRS in advance, allowing the terminal to use two VRSs for RTK positioning and solution at the same time. When the terminal actually uses the next VRS, it can already perform the solution based on the differential data of the next VRS and obtain higher accuracy.

[0047] For example, the Chinese invention patent with application number 201810173064.X broadcasts the differential data of the neighboring VRS to the terminal through the server in advance before the actual physical position of the terminal enters the neighboring VRS from the main VRS, so that the terminal can perform positioning solution based on the differential data of the neighboring VRS in advance. When the actual physical position of the terminal enters the neighboring VRS, the terminal has entered the fixed solution state based on the differential data of the neighboring VRS and obtained a higher accuracy.

[0048] However, in the above-mentioned related technologies, there are the following two defects:

[0049] 1. Large data transmission volume: When preparing for VRS switching, the terminal needs to receive the differential data of two VRSs at the same time. This will put a heavy burden on the mobile station terminal for most devices that need to use wireless traffic and are charged according to traffic. At the same time, a larger data volume is more likely to cause data loss during transmission and reception.

[0050] 2. Heavy computing burden on the terminal: When preparing for VRS switching, the terminal needs to use the differential data of two VRSs for calculation at the same time, which will significantly increase the computing burden of the terminal. Considering that the computing power of the terminal is usually limited, the above-mentioned related technologies are likely to be difficult to implement on the receiver of low-cost terminals.

[0051] In order to solve the problems of large data transmission volume and heavy terminal computing burden in the current network RTK technology broadcast using the VRS method, the embodiment of the present application provides a related technical solution for VRS switching in large-scale motion scenarios.

[0052] Various related technical solutions provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0053] Before introducing the embodiments of the present application, some terms in the present application are first explained to facilitate understanding by those skilled in the art.

[0054] Network RTK is a high-precision differential positioning technology based on the Global Navigation Satellite System (GNSS) that can achieve centimeter-level real-time positioning. The core idea is to receive satellite signals through multiple base stations with known locations, correct the errors, and then transmit the correction information to the terminal through a data link (such as the Internet or wireless network). The terminal combines these correction data to correct its positioning results in real time, thereby greatly improving positioning accuracy. Network RTK is suitable for high-precision positioning needs in large areas and complex environments, and is widely used in surveying, geographic information systems, engineering, unmanned driving and other fields.

[0055] VRS is an optimized implementation of network RTK technology. Traditional RTK positioning relies on one or more physical reference stations. The farther the terminal is from the reference station, the greater the error. VRS creates a virtual reference station through a reference station network, whose location is close to the actual location of the terminal. In this way, the correction data received by the terminal has a higher spatial correlation with its own position, which effectively reduces the impact of the reference station distance error, and significantly improves positioning accuracy and stability, especially in the case of long baselines. The VRS system usually generates correction data based on the location of the terminal, which makes this technology advantageous in large-scale, high-density GNSS positioning services.

[0056] Among them, when VRS technology is used in static scenes, the terminal remains motionless and the VRS is also fixed, so there is no problem of switching VRS. However, in dynamic scenes, the position of terminals such as cars, drones, or mobile phones is constantly changing, and VRS also needs to be adjusted accordingly. For example, when a car is driving at high speed, the position change will cause the car to be farther away from the VRS originally used. Therefore, in dynamic scenes, it is usually necessary to switch VRS to maintain positioning accuracy. However, when the terminal switches from one VRS to another, there will be a short delay, resulting in a decrease in positioning accuracy. This fluctuation in accuracy is not ideal for high-reliability scenarios such as autonomous driving.

[0057] Figure 1 FIG. 2 is a flow chart showing a VRS switching method according to an embodiment of the present application. Figure 1 As shown, the method can be applied to the server, including the following steps:

[0058] S110: Receive the approximate location reported by the terminal.

[0059] In one implementation, the approximate position can be obtained by performing RTK positioning of the terminal based on differential data of a nearby VRS, wherein the terminal generates a filtering solution result during the RTK positioning process.

[0060] As an example, the implementation process of step S110 may include the following steps:

[0061] S111: Receive a positioning request initiated by a terminal and its own approximate position reported.

[0062] In specific implementation, after the terminal is connected to the server, it can initiate the positioning request to the server and report its approximate location. Correspondingly, the server receives the positioning request and the approximate location.

[0063] S112. Based on the positioning request, obtain the original data of the reference station closest to the approximate position and the baseline solution results between the reference stations.

[0064] In specific implementation, the CORS system can perform baseline solution between the reference stations during the Delaunay networking of the reference stations to obtain the baseline solution result.

[0065] It can be understood that the baseline solution results between the various reference stations in the CORS system can be directly obtained later.

[0066] As an example, taking the CORS system including 6 reference stations as an example, the Delaunay triangulation network composed of these 6 reference stations can be as follows: Figure 2 shown.

[0067] S113. Generate differential data of the VRS near the terminal based on the original data and the baseline solution result.

[0068] S114. Broadcast the differential data of the nearby VRS to the terminal, and the terminal performs RTK positioning based on the differential data to obtain its own approximate position and report the approximate position.

[0069] In specific implementation, the terminal can continuously locate itself based on the differential data of nearby VRSs and continuously report its approximate location to the server.

[0070] In specific implementation, the terminal will generate filtering solution results during the RTK positioning process.

[0071] It should be understood that the above steps S111 to S115 can be implemented using existing technologies, that is, step S110 can be implemented using existing technologies, and the embodiments of the present application will not be repeated here.

[0072] S120. When it is determined based on the approximate position that the terminal needs to switch VRS and the main reference station, the ambiguity difference of each satellite before and after switching the main reference station is calculated and recorded as the ambiguity baseline change value.

[0073] In one implementation, the server may determine a first VRS (i.e., the new VRS described below) that matches the approximate location, and when it is determined that the first VRS is not the same as the second VRS obtained in the previous match (i.e., the nearby VRS described above), it may be determined that the terminal needs to switch VRS. The server may determine the first VRS in a manner that uses existing technology, and this embodiment of the present application will not be described in detail.

[0074] In one implementation, when determining that the terminal needs to switch VRS, the server can determine whether the primary reference station used to generate the differential data of the VRS is switched when the VRS is switched. The primary reference station is the reference station used to generate the differential data of the VRS.

[0075] In specific implementation, the server may use existing technologies to determine whether the primary reference station used to generate differential data for the VRS is switched when the VRS is switched, and the embodiments of the present application will not be described in detail herein.

[0076] Exemplary, combined Figure 2 and Figure 3 As shown, taking the first VRS as VRS2 and the second VRS as VRS1 as an example, when switching from VRS1 to VRS2, the main reference station used to generate the differential data of the VRS is switched from reference station 1 to reference station 3.

[0077] In one embodiment, when the server determines that the terminal needs to switch VRS and the main reference station based on the approximate position, it can calculate the ambiguity difference of each satellite before and after switching the main reference station, and then record the calculated ambiguity difference of each satellite before and after switching the main reference station as the ambiguity baseline change value.

[0078] As an example, the implementation process of calculating the ambiguity difference of each satellite of the switching main reference station may include the following steps:

[0079] S121. Obtain baseline solution results between reference stations.

[0080] S122. Based on the baseline solution result and the specified double difference model, the ambiguity difference of each satellite before and after switching the main reference station is calculated by filtering and fixing the ambiguity.

[0081] Exemplarily, a double difference model commonly used by a terminal for positioning solution based on VRS differential data can be shown as the following formula (1).

[0082]

[0083] in, represents the double difference sign between satellite pq and receiver uv; P and L represent the pseudorange observation and carrier phase observation at frequency j of satellite s and receiver r, respectively; E(*) represents the expectation operator; ρ is the distance between the satellite and the receiver; λ is the wavelength; N is the integer ambiguity; other biases are assumed to be pre-corrected by the model.

[0084] Based on formula (1), as the positioning time of the terminal increases, the ambiguity of each satellite gradually converges and becomes an integer, and the RTK positioning can achieve high accuracy. Figure 3 As shown in the figure, assuming that the primary reference station used to generate VRS differential data is switched from reference station 1 to reference station 3, will become The filtering solution result obtained by the terminal when performing RTK positioning when switching VRS includes the various parameters converged in formula (1), including the integer ambiguity of each satellite.

[0085] Based on this, in the embodiment of the present application, the server can calculate the ambiguity difference of each satellite before and after switching the main reference station based on the baseline solution result and the specified double difference model by filtering and fixing the ambiguity to obtain The change value of .

[0086] Exemplarily, the specified double difference model may be as shown in formula (2).

[0087]

[0088] Where Z is the zenith moist tropospheric delay, M is the mapping function from the zenith direction to the oblique direction; μj is the frequency from 1(f 1 ) to frequency j(f j ), whose value can be set to is the remaining ionospheric residual.

[0089] In this example, the server can calculate the ambiguity difference of each satellite before and after switching the main reference station based on the baseline solution result and the specified double difference model by filtering and fixing the ambiguity.

[0090] S130. Generate a first telegram including the ambiguity baseline change value.

[0091] In one implementation, the first electronic message may be generated using a custom electronic message format.

[0092] As an example, the custom message format may include the format fields of synchronization word, message type, message length, primary reference station switching flag, reference station ID before switching, reference station ID after switching, satellite ambiguity change data and CRC check code. Among them, the satellite ambiguity change data may include satellite PRN code, L1 frequency ambiguity change and L2 frequency ambiguity change. It can be understood that the custom message format is a supplement to the standard RTCM message.

[0093] Exemplarily, the various format fields of the custom message format may be as shown in Table 1 below.

[0094] Table 1

[0095]

[0096] Exemplarily, the satellite ambiguity change data in Table 1 above may be as shown in Table 2 below.

[0097] Table 2

[0098]

[0099] As an example, assuming that it is necessary to broadcast an RTCM message about the reference station switching and containing the ambiguity changes of two satellites, the message content of the RTCM message can be as shown in Table 3 below.

[0100] Table 3

[0101]

[0102]

[0103] That is to say, in combination with Table 1 and Table 2, in the RTCM message example of Table 3, the first message including the ambiguity reference change value obtained according to the above step S120 may be generated as follows:

[0104] 34FFCC538A3020017FFEC20002800858241A.

[0105] S140: broadcast the differential data between the first message and the new VRS to the terminal.

[0106] In one embodiment, by executing step S140, when the terminal receives the first message, it can use the old filtering solution result to perform RTK positioning based on the differential data of the ambiguity baseline change value and the new VRS (the specific process is described below).

[0107] In a specific implementation, the server may play the differential data of the first message and the new VRS to the terminal respectively, wherein the embodiment of the present application does not limit the order in which the server plays the differential data of the first message and the new VRS.

[0108] Based on the above formula (1), we can know that Figure 3 As shown in the figure, assuming that the primary reference station used to generate VRS differential data is switched from reference station 1 to reference station 3, will become This process will cause the previously converged No longer available, the terminal needs to reconverge parameters when performing RTK positioning

[0110] Based on this, in an embodiment of the present application, by broadcasting a first message to the terminal, the terminal can be informed of the specific ambiguity baseline change values ​​of all satellites in the switching VRS.

[0111] That is, through the above steps S120 to S140, the server can obtain the baseline solution results between the reference stations. The change value is broadcast to the terminal, and the terminal can correct the ambiguity of each satellite through this change value, and can continue to use the original converged parameters and the differential data of the new VRS for RTK positioning.

[0112] In summary, in the VRS switching method provided in the embodiment of the present application, by executing steps S110 to S140, the server determines that the terminal needs to switch VRS and needs to switch the main reference station based on the approximate position reported by the terminal, calculates the ambiguity difference of each satellite before and after switching the main reference station, and broadcasts the first telegram containing the ambiguity reference change value to the terminal, so that when the terminal switches VRS and uses the differential data of the new VRS for RTK positioning, it can continue to use the old filtering solution result to achieve high-precision operation, and the ambiguity of each satellite calculated previously does not need to be reinitialized or re-fixed, thereby avoiding the situation where the high-precision positioning of the terminal (i.e., the user) is discontinuous and needs to be reinitialized when the VRS is switched in the case of large-scale movement.

[0113] In an applicable scenario provided in the embodiment of the present application, for example Figure 1 As shown, the VRS switching method provided in the embodiment of the present application may also include the following steps:

[0114] S150. When it is determined based on the approximate position that the terminal needs to switch the VRS but does not need to switch the primary reference station, a second message is generated to indicate the change of the ambiguity-free reference of each satellite.

[0115] In one embodiment, when the server determines based on the approximate position that the terminal needs to switch VRS and does not need to switch the main reference station, it can be determined that when the VRS is switched, there is no ambiguity baseline change for each satellite. At this time, a second telegram can be generated to indicate that there is no ambiguity baseline change for each satellite.

[0116] Exemplary, combined Figure 2 and Figure 4 As shown, taking the first VRS as VRS2 and the second VRS as VRS1 as an example, when switching from VRS1 to VRS2, the main reference station used to generate the differential data of the VRS remains unchanged, and is still reference station 1.

[0117] As an example, the server may generate the second telegram in the same or similar manner as that of generating the first telegram, or may generate the second telegram in other manners, which is not limited in the embodiments of the present application.

[0118] S160: broadcast the second message and the differential data of the new VRS to the terminal.

[0119] In one embodiment, by executing step S160, the terminal can determine that there is no ambiguity baseline change for each satellite when receiving the second message, and directly perform RTK positioning based on the differential data of the new VRS using the old filtering solution result (the specific process is described below).

[0120] Currently, the terminal cannot determine whether the main reference station has been switched. Therefore, each time RTK positioning is performed, the ambiguity of each satellite needs to be reinitialized and refixed. By broadcasting the second message to the terminal, the terminal can be informed that there is no ambiguity baseline change for each satellite, and there is no need to reinitialize or refix the ambiguity of each satellite.

[0121] In summary, in the VRS switching method provided in the embodiment of the present application, by executing step S110, step S150-step S160, the server determines that the terminal needs to switch VRS based on the approximate position reported by the terminal and does not need to switch the main reference station. The server broadcasts a second telegram to the terminal indicating that the ambiguity reference of each satellite has changed. When the terminal switches VRS, it can directly use the differential data of the new VRS and continue to use the old filtering solution results for RTK positioning, thereby achieving high-precision operation, thereby avoiding the situation where the high-precision positioning of the terminal is discontinuous and needs to be reinitialized when the VRS is switched in the case of large-scale movement.

[0122] That is Figure 1 In the VRS switching method shown, the server only needs to switch from broadcasting the differential data of the old VRS to broadcasting the differential data of the new VRS as usual without considering the re-convergence problem. In this process, a custom message with a very small amount of data (i.e., the first message / the second message) is broadcast. In this way, the terminal can perform RTK positioning based on the custom message based on the differential data of the new VRS and the old filtering solution, without the need to simultaneously receive the differential data of two VRSs and perform two RTK positioning at the same time.

[0123] Figure 5 FIG. 2 is a flow chart showing another VRS switching method according to an embodiment of the present application. Figure 5 As shown, the method can be applied to a terminal and comprises the following steps:

[0124] S210: Perform RTK positioning based on the differential data of the nearby VRS to obtain a rough position, and report the rough position to the server.

[0125] In specific implementation, the terminal will generate filtering solution results during the RTK positioning process.

[0126] In one implementation, the implementation process of step S210 may refer to the implementation process of the above-mentioned step S110, and the embodiment of the present application will not be repeated here.

[0127] S220: When receiving the first message including the ambiguity reference change value and the differential data of the new VRS broadcasted by the server, the old filtering solution result is used to perform RTK positioning based on the differential data of the ambiguity reference change value and the new VRS.

[0128] In specific implementation, the embodiment of the present application does not limit the order in which the terminal receives the differential data of the first electronic message and the new VRS.

[0129] In one embodiment, the ambiguity baseline change value is obtained by calculating and recording the ambiguity difference of each satellite before and after switching the main reference station when the server determines based on the approximate position that the terminal needs to switch VRS and needs to switch the main reference station. The main reference station is the reference station used to generate the differential data of the VRS (for details, please refer to the relevant description of the above step S120).

[0130] In one implementation, the implementation process of the terminal using the old filtering solution result to perform RTK positioning based on the ambiguity reference change value and the differential data of the new VRS may be:

[0131] The terminal adds the ambiguity baseline change value to the integer ambiguity of each satellite included in the old filtering solution result, and resets the remaining satellite ambiguity information not included in the old filtering solution result with a cycle jump (i.e. resets and clears the ambiguity information not including each satellite), and then uses the differential data of the new VRS for RTK positioning.

[0132] In summary, in the VRS switching method provided in the embodiment of the present application, by executing steps S210-S220, when the terminal receives the differential data of the new VRS broadcast by the server and receives the first telegram broadcast by the server, it can directly add the ambiguity baseline change value to the integer ambiguity of each satellite in the old filtering solution result according to the message content of the first telegram (that is, the ambiguity baseline change value) to correct the ambiguity and continue to use it in the filtering solution process, without re-initializing the ambiguity of each satellite and without re-fixing the ambiguity of each satellite.

[0133] In another applicable scenario provided in the embodiment of the present application, such as Figure 5 As shown, the VRS switching method provided in the embodiment of the present application may also include the following steps:

[0134] S230: When receiving the second message broadcasted by the server indicating that there is no ambiguity reference change for each satellite and the differential data of the new VRS, it is determined that there is no ambiguity reference change for each satellite, and RTK positioning is performed directly based on the differential data of the new VRS using the old filtering solution result.

[0135] In a specific implementation, the second message is generated when the server determines that the terminal needs to switch VRS based on the approximate location and does not need to switch the main reference station (for details, please refer to the relevant description of the above step S150).

[0136] Currently, the terminal cannot determine whether the main reference station has been switched. Therefore, each time RTK positioning is performed, the ambiguity of each satellite needs to be reinitialized and re-fixed. Based on this, the terminal can directly determine that there is no ambiguity baseline change for each satellite when receiving the second message broadcast by the server.

[0137] In summary, in the VRS switching method provided in the embodiment of the present application, by executing step S210 and step S230, when the terminal switches the VRS, when receiving the second message broadcast by the server, it can directly determine that there is no ambiguity baseline change for each satellite, and there is no need to reinitialize the ambiguity of each satellite or refix the ambiguity of each satellite. The differential data of the new VRS can be directly used to continue using the old filtering solution results for RTK positioning, thereby achieving high-precision operation, thereby avoiding the situation where the high-precision positioning of the terminal is discontinuous and needs to be reinitialized when the VRS is switched in the case of large-scale movement.

[0138] That is Figure 5 In the VRS switching method shown, the terminal only needs to perform RTK positioning based on the differential data of the new VRS and the old filter solution when receiving the differential data of the new VRS and the custom telegram (first telegram / second telegram) broadcast by the server. There is no need to receive the differential data of two VRSs at the same time and perform two RTK positioning at the same time.

[0139] It can be seen from the above description that the VRS switching method provided in the embodiment of the present application can achieve the following effects:

[0140] (I) Small amount of data transmission: Compared with the above-mentioned related technologies, when VRS switching may be required, the server needs to broadcast the differential data of the old VRS and the differential data of the new VRS to the terminal at the same time, and the terminal uses these two differential data for RTK positioning at the same time. In this application, the server only needs to broadcast the corresponding telegram of the differential data of the new VRS to the terminal. In terms of data volume, the data volume of the telegram is significantly smaller than that of the differential data of the VRS. That is, this application can significantly reduce the amount of data transmission.

[0141] (II) The terminal has a light computing burden: Compared with the above-mentioned related technologies, when VRS switching may be required, the terminal needs to simultaneously receive the differential data of two VRSs, and the terminal needs to use the differential data of the two VRSs to perform two RTK positionings, the present application only requires the terminal to receive the differential data of the new VRS, and only requires the terminal to adjust some of the parameters to be estimated before the switching according to the received ambiguity reference change, that is, the terminal only needs to use the same amount of data and computing as when the VRS is not switched for RTK positioning, and can continuously achieve high-precision operations within a larger CORS range. That is, the present application can significantly reduce the computing burden of the terminal.

[0142] That is, the present application reduces the amount of data transmission between the server and the terminal and alleviates the computing burden of the terminal, so that the terminal can meet the continuous high-precision positioning requirements when VRS switching occurs in large-scale motion scenarios.

[0143] Figure 6 FIG. 2 shows a structural block diagram of a VRS switching device according to an embodiment of the present application. Figure 6 As shown, the VRS switching device includes: a memory 310 and a processor 320, wherein the memory 310 stores instructions, and the instructions are loaded and executed by the processor 320 to implement the above-mentioned embodiment. Figure 1 The VRS switching method shown in the figure, or the implementation of the above embodiment Figure 5 The VRS switching method shown. The number of the memory 310 and the processor 320 can be one or more.

[0144] The VRS switching device also includes:

[0145] The communication interface 330 is used to communicate with external devices and perform data exchange transmission.

[0146] If the memory 310, the processor 320 and the communication interface 330 are implemented independently, the memory 310, the processor 320 and the communication interface 330 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0147] Optionally, in a specific implementation, if the memory 310, the processor 320 and the communication interface 330 are integrated on a chip, the memory 310, the processor 320 and the communication interface 330 can communicate with each other through an internal interface.

[0148] An embodiment of the present application provides a computer-readable storage medium, in which a computer program is stored. When the computer program runs on a computer, the method provided in the embodiment of the present application is implemented.

[0149] An embodiment of the present application also provides a chip, which includes a processor for calling and executing instructions stored in a memory, so that a communication device equipped with the chip executes the method provided by the embodiment of the present application.

[0150] An embodiment of the present application also provides a chip, including: an input interface, an output interface, a processor and a memory, wherein the input interface, the output interface, the processor and the memory are connected via an internal connection path, and the processor is used to execute the code in the memory. When the code is executed, the processor is used to execute the method provided in the embodiment of the application.

[0151] It should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. It is worth noting that the processor may be a processor supporting the Advanced RISC Machines (ARM) architecture.

[0152] Further, optionally, the above-mentioned memory may include a read-only memory and a random access memory, and may also include a non-volatile random access memory. The memory may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may include a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may include a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available. For example, static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct rambus RAM (DR RAM).

[0153] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium.

[0154] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0155] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0156] Any process or method description in the flow chart or otherwise described herein can be understood to represent a module, fragment or portion of a code including one or more executable instructions for implementing the steps of a specific logical function or process. And the scope of the preferred embodiment of the present application includes other implementations, in which the functions may not be performed in the order shown or discussed, including in a substantially simultaneous manner or in a reverse order according to the functions involved.

[0157] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, which can be embodied in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a system including a processor or other system that can fetch instructions from an instruction execution system, apparatus or device and execute instructions), or used in combination with these instruction execution systems, apparatuses or devices.

[0158] It should be understood that the various parts of the present application can be implemented with hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented with software or firmware stored in a memory and executed by a suitable instruction execution system. All or part of the steps of the above embodiment method can be completed by instructing the relevant hardware through a program, which can be stored in a computer-readable storage medium, and when the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0159] In addition, each functional unit in each embodiment of the present application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. If the above-mentioned integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The storage medium can be a read-only memory, a disk or an optical disk, etc.

[0160] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A VRS switching method, characterized in that: include: Receiving an approximate position reported by a terminal, wherein the approximate position is obtained by performing RTK positioning of the terminal based on differential data of a nearby VRS, wherein the terminal generates a filtering solution result during the RTK positioning process; When it is determined based on the approximate position that the terminal needs to switch VRS and needs to switch the main reference station, the ambiguity difference of each satellite before and after switching the main reference station is calculated and recorded as the ambiguity reference change value, and the main reference station is the reference station used to generate the differential data of the VRS; generating a first electronic message including the ambiguity reference change value; The differential data of the first message and the new VRS is broadcasted to the terminal, and when the terminal receives the first message, the terminal uses the old filtering solution result to perform RTK positioning based on the differential data of the ambiguity reference change value and the new VRS.

2. The method according to claim 1, characterized in that The method further comprises: When it is determined based on the approximate position that the terminal needs to switch the VRS and does not need to switch the primary reference station, generating a second message indicating a change in the ambiguity-free reference of each satellite; The second message and the differential data of the new VRS are broadcasted to the terminal. When the terminal receives the second message, it determines that there is no ambiguity baseline change for each satellite, and directly uses the old filtering solution result based on the differential data of the new VRS for RTK positioning.

3. The method according to claim 1, characterized in that The calculation of the ambiguity difference of each satellite before and after switching the main reference station includes: Obtain the baseline solution results between each reference station; Based on the baseline solution result and the specified double difference model, the ambiguity difference of each satellite before and after switching the main reference station is calculated by filtering and fixing the ambiguity.

4. The method according to claim 3, characterized in that The specified double difference model is expressed as: in, represents the double difference sign between satellite pq and receiver uv; P and L represent the pseudorange observation value and carrier phase observation value at the corresponding frequency j of satellite s and receiver r, respectively; E(*) represents the expectation operator; ρ is the distance between the satellite and the receiver; λ is the wavelength; N is the integer ambiguity, Z is the zenith wet tropospheric delay, and M is the mapping function from the zenith direction to the oblique direction; μ j is the frequency-dependent scaling factor from frequency 1 to frequency j; is the remaining ionospheric residual.

5. The method according to any one of claims 1 to 4, characterized in that Generating a first electronic message including the ambiguity reference change value comprises: Generate the first telegram using a custom telegram format; The custom message format includes the format fields of synchronization word, message type, message length, main reference station switching flag, reference station ID before switching, reference station ID after switching, satellite ambiguity change data and CRC check code, and the satellite ambiguity change data includes satellite PRN code, L1 frequency ambiguity change and L2 frequency ambiguity change.

6. A VRS switching method, characterized in that: include: Perform RTK positioning based on the differential data of nearby VRS to obtain a rough position, and report the rough position to the server. In the process of RTK positioning, a filtering solution result is generated; When receiving the first message including the ambiguity reference change value and the differential data of the new VRS broadcasted by the server, the old filtering solution result is used for RTK positioning based on the differential data of the ambiguity reference change value and the new VRS; Among them, the ambiguity baseline change value is obtained by calculating and recording the ambiguity difference of each satellite before and after switching the main reference station when the server determines that the terminal needs to switch VRS and needs to switch the main reference station based on the approximate position. The main reference station is the reference station used to generate differential data of VRS.

7. The method according to claim 6, characterized in that The method further comprises: When receiving the second message broadcast by the server indicating that there is no ambiguity reference change for each satellite and the differential data of the new VRS, it is determined that there is no ambiguity reference change for each satellite, and RTK positioning is performed directly based on the differential data of the new VRS using the old filtering solution result. The second message is generated when the server determines that the terminal needs to switch VRS based on the approximate position and does not need to switch the main reference station.

8. The method according to claim 6 or 7, characterized in that: Using the old filtering solution result to perform RTK positioning based on the ambiguity reference change value and the differential data of the new VRS includes: The ambiguity baseline change value is added to the integer ambiguity of each satellite included in the old filtering solution result, and the remaining satellite ambiguity information not included in the old filtering solution result is reset with a cycle jump, and then the differential data of the new VRS is used for RTK positioning.

9. A VRS switching device, characterized in that: include: A memory and a processor, wherein the memory stores instructions, and the instructions are loaded and executed by the processor to implement the method according to any one of claims 1 to 5 or the method according to any one of claims 6 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed on a computer, the method according to any one of claims 1 to 5 or the method according to any one of claims 6 to 8 is implemented.

Images