Indoor GPS positioning method and system

Abstract

The invention provides an indoor GPS positioning method and system. The method comprises the following steps: determining a difference value of propagation distances of two adjacent time points based on a GPS receiving end; calculating a satellite motion direction vector based on the satellite height and the trajectory vectors of the two adjacent time points of the satellite; calculating an indoor vector based on the difference value of the propagation distances of the two adjacent time points, the satellite motion direction vector and the difference value of the direct distances between the GPS receiving end and the satellite at the two adjacent time points, wherein the indoor vector corresponds to a propagation vector from the repeater to the GPS receiving end; and positioning the position of the GPS receiving end based on the propagation vector. According to the scheme, modeling is carried out on calculation of the indoor vector in advance, estimation of the indoor vector is completed through the difference value of two adjacent measurements in time, and the indoor vector can be determined and indoor positioning can be completed on the premise that the position of the repeater is not determined in advance.

Description

Technical Field

[0001] The present invention relates to the field of indoor positioning technology, and in particular to an indoor GPS positioning method and system. Background Art

[0002] The Global Positioning System (GPS), also known as the Global Positioning System, is a medium-orbit satellite navigation system. It can provide accurate positioning, speed measurement and high-precision standard time synchronization for most areas on the earth's surface. The global positioning system can meet the needs of users located anywhere on the ground or in near-earth space to continuously and accurately determine three-dimensional position, three-dimensional movement and time. The system includes 31 GPS artificial satellites in space; 1 master control station, 3 data injection stations and 5 monitoring stations on the ground, as well as GPS receivers and smart phones as user terminals. At least 4 satellites are needed to quickly determine the location and altitude of the user terminal on the earth; the more satellite signals that can be received, the more accurate the decoded position. At the same time, because it uses time difference positioning, it can also accurately correct the time stamp. The GPS system has the following advantages: using low-frequency signals, it can still maintain considerable signal penetration even in bad weather; up to 98% global coverage; high-precision three-dimensional fixed speed and timing; fast, time-saving, and efficient; widely used and multi-functional; mobile positioning. Due to its high availability and universality, most navigation and synchronization applications are completed using GPS.

[0003] Although GPS shows high robustness in outdoor environments, it is almost unusable in indoor scenarios. First, the satellite's LoS signal is difficult to penetrate obstacles such as walls or iron sheds. In addition, the existing indoor positioning method needs to determine the location of the repeater, build an indoor vector based on the location of the repeater and the user's GPS receiver, and then perform positioning through the indoor vector. Therefore, the positioning adaptability of the existing technology is poor. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides an indoor GPS positioning method and system to eliminate or improve one or more defects in the prior art.

[0005] One aspect of the present invention provides an indoor GPS positioning method, the method comprising the steps of:

[0006] Determine the difference in propagation distance between two adjacent time points based on the GPS receiver;

[0007] Calculate the satellite motion direction vector based on the satellite altitude and the satellite trajectory vector at two adjacent time points;

[0008] Calculate an indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, wherein the indoor vector corresponds to a propagation vector from the repeater to the GPS receiver;

[0009] The position of the GPS receiver is located based on the propagation vector.

[0010] Using the above scheme, in the positioning scheme of this scheme, since the distance value that the GPS receiver can measure is actually the sum of the distance from the satellite to the repeater and the distance from the repeater to the GPS receiver, this scheme pre-models the calculation of the indoor vector, and completes the estimation of the indoor vector through the difference between two adjacent measurements in time. This scheme can determine the indoor vector and complete indoor positioning without pre-determining the position of the repeater.

[0011] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the satellite motion direction vector is calculated based on the satellite's motion trajectory vector and the satellite altitude value at two adjacent time points.

[0012] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between a GPS receiver and a satellite at two adjacent time points, the pseudorange rate is determined based on the GPS measurement results, and the pseudorange rate is used as the difference in direct distances between the satellite at two adjacent time points.

[0013] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the indoor vector is calculated based on the following formula:

[0014]

[0015] Among them, mov sat,(t→t+1) H represents the motion trajectory vector of the satellite at two adjacent time points; sat Indicates the satellite altitude; δρ t Represents the difference in propagation distance between two adjacent time points; PRR t+1 represents the pseudorange rate at the later time point between two time points, k t Indicates the indoor vector of the previous time point between two adjacent time points of the satellite.

[0016] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the motion trajectory vector of the satellite at two adjacent time points among four consecutive time points, the satellite altitude value, the difference in propagation distances between two adjacent time points, and the pseudorange rate at the moment of the latter time point between each two adjacent time points are obtained, and a group of equations including three equations are jointly established to calculate the x, y, and z values ​​in the indoor vector.

[0017] In some embodiments of the present invention, the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points further includes:

[0018] Calculating three displacement vectors of four consecutive time points determined by the GPS receiving end;

[0019] Based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances between two adjacent time points, the pseudorange rate at the moment of the latter time point between every two adjacent time points and the three displacement vectors of the user in four consecutive time points, a group of equations including three equations is jointly established to calculate the x, y and z values ​​in the indoor vector at the first time point.

[0020] In some embodiments of the present invention, based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances at two adjacent time points, the pseudorange rate at the moment of the latter time point in each two adjacent time points, and the three-segment displacement vector of the user at four consecutive time points, a system of equations including three equations is jointly established to calculate the x, y, and z values ​​in the indoor vector at the first time point, the x, y, and z values ​​in the indoor vector at the first time point are calculated based on the following formula:

[0021]

[0022] Among them, mov sat,(t→t+1) H represents the motion trajectory vector of the satellite at two adjacent time points; sat Indicates the satellite altitude; δρ t Represents the difference in propagation distance between two adjacent time points; PRR t+1 represents the pseudorange rate at the later time point between two time points, k t Indicates the indoor vector of the satellite at the previous time point between two adjacent time points, Δk t+1 Represents the displacement vector of the satellite at two adjacent time points.

[0023] In some embodiments of the present invention, based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances at two adjacent time points, the pseudo-range rate at the moment of the latter time point in each of two adjacent time points, and the three-segment displacement vector of the user at four consecutive time points, a system of equations including three equations is simultaneously established to calculate the x, y, and z values ​​in the indoor vector at the first time point, the system of equations is expressed as:

[0024]

[0025] In some embodiments of the present invention, in the step of calculating the three displacement vectors of four consecutive time points determined by the GPS receiving end, IMU measurement and GPS Doppler measurement of the three displacement vectors of four consecutive time points are used.

[0026] In some embodiments of the present invention, in the step of measuring three displacement vectors at four consecutive time points using IMU measurement and GPS Doppler measurement, the value of the displacement vector measured by IMU and the direction of the displacement vector measured by GPS Doppler measurement are obtained to construct the final displacement vector.

[0027] The second aspect of the present invention also provides an indoor GPS positioning system, which includes a computer device, the computer device includes a processor and a memory, the memory stores computer instructions, the processor is used to execute the computer instructions stored in the memory, and when the computer instructions are executed by the processor, the system implements the steps implemented by the method described above.

[0028] The third aspect of the present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps implemented by the aforementioned indoor GPS positioning method are implemented.

[0029] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention can be specifically pointed out and obtained in the specification and the accompanying drawings.

[0030] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention.

[0032] Figure 1 This is a schematic diagram of an implementation method of the indoor GPS positioning method of this scheme;

[0033] Figure 2 This is a schematic diagram of another implementation method of the indoor GPS positioning method of this scheme;

[0034] Figure 3 This is a comparison diagram of indoor positioning and outdoor positioning;

[0035] Figure 4 This is a schematic diagram of existing GPS indoor positioning;

[0036] Figure 5 This is a schematic diagram of the existing indoor GPS relay assisted positioning process. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0038] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0039] In the prior art, although GPS shows high robustness in outdoor environments, it is almost unusable in indoor scenarios because the satellite's LoS signal can hardly penetrate obstacles such as walls or iron sheds. Existing solutions use GPS relay devices with known locations to provide indoor GPS signal coverage. A typical GPS relay uses a pair of GPS antennas connected by an RF cable to achieve coverage of the received outdoor GPS signal indoors, and connects to the user through another communication channel to inform its location. Although there is GPS signal coverage indoors, the GPS signal received from the relay will introduce distance estimation errors due to the NLOS signal propagation path of satellite-relay-user. Users rely on known information about the relay's location to further locate themselves by using the relay as an anchor point. Some methods obtain the relay's location and calculate the relay-user distance by directly interacting with the relay, and directly complete positioning with the relay as the anchor point; while other methods use differential positioning to calculate the propagation distance difference of signals from different relays to complete positioning. Therefore, when the relay location information is not available, the existing methods will fail immediately. For example Figure 4 As shown in the figure on the left, when GPS users know the indoor relay deployment location, they can use this information to correct their positioning results and achieve accurate positioning. Figure 4As shown in the figure on the right, users cannot obtain the specific information of the relay location, so the positioning accuracy drops sharply due to the NLoS path. The applicability and scalability of existing methods are very limited.

[0040] Prior art 1:

[0041] Existing technology Figure 5 As shown in the figure, using GPS relay, an outdoor hypothetical GPS receiver receives GPS signals and transmits the signals to indoors through wires, and regenerates and broadcasts GPS signals indoors. Users use the indoor broadcast signals to complete distance measurement, and use the relayed coordinates and the time delay of the signal from outdoor to indoor to complete their own positioning.

[0042] The system uses indoor relays as anchor points for positioning, requiring the receiver, i.e. the user, to know the deployment location of the indoor relays and calculate the receiver's own positioning coordinates accordingly. If the user enters this scene for the first time and cannot understand the relay deployment information, the positioning will fail directly.

[0043] In addition, GPS relay deployment requires deploying a receiver outdoors and a transmitter indoors, and connecting them with cables to transmit the signal indoors, which makes deployment very difficult.

[0044] After providing GPS signals for indoor scenes, this solution needs to correct the user's positioning according to the indoor scene. Previous methods have used the location of the relay and GPS measurement data to complete indoor positioning, which limits the availability and versatility of GPS services.

[0045] like Figure 1 As shown, the present invention proposes an indoor GPS positioning method, the steps of which include:

[0046] Step S100, determining the difference in propagation distances between two adjacent time points based on the GPS receiving end;

[0047] In a specific implementation process, the GPS-based receiving terminal may be a user's mobile terminal, specifically a mobile phone, a laptop computer, or a tablet computer.

[0048] Step S200, calculating the satellite motion direction vector based on the satellite altitude and the trajectory vector of the satellite at two adjacent time points;

[0049] In the specific implementation process, the ratio of the trajectory vector of the satellite at two adjacent time points to the satellite altitude is calculated as the satellite motion direction vector.

[0050] In a specific implementation process, the trajectory vector and the satellite altitude of two adjacent time points of the satellite can be obtained from the ephemeris data of the satellite.

[0051] Step S310, calculating an indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite between two adjacent time points, wherein the indoor vector corresponds to a propagation vector from the repeater to the GPS receiver;

[0052] Step S400: locating the position of the GPS receiver based on the propagation vector.

[0053] Using the above scheme, in the positioning scheme of this scheme, since the distance value that the GPS receiver can measure is actually the sum of the distance from the satellite to the repeater and the distance from the repeater to the GPS receiver, this scheme pre-models the calculation of the indoor vector, and completes the estimation of the indoor vector through the difference between two adjacent measurements in time. This scheme can determine the indoor vector and complete indoor positioning without pre-determining the position of the repeater.

[0054] In the specific implementation process, in normal outdoor scenes, such as Figure 3 As shown in the schematic diagram in the middle room, the GPS receiver calculates the pseudorange ρ by calculating the delay between its own clock and the satellite clock, and then calculates the distance ||L|| between the satellite and the receiver through the pseudorange, that is:

[0055] ρ=||L||+cδ t +c(-δ s +I+T)+∈ ρ ;

[0056] Where c is the speed of light, δ t is the clock difference between the satellite and the receiver, (δ s ,I,T) are the clock errors of satellite and GPS clocks, ionospheric delay and tropospheric delay of GPS signal respectively. These three items can be modeled and eliminated from the navigation information provided by GPS,∈ ρ is the pseudorange measurement error caused by noise. s ,y s ,z s ), we can establish the equation:

[0057]

[0058] From the four different equations above, i.e., the pseudo-range measurements from four different satellites, the coordinates of the receiver and the clock error (x, y, z, δ t ), thus completing the positioning.

[0059] Under the refraction model, the pseudorange measurement result is not the direct satellite-receiver distance, but the refraction distance from satellite to metasurface to receiver. Figure 3As shown in the schematic diagram outside the middle room, the result of the pseudorange is not ||L||, but ||S||+||k||. The goal of this scheme is to first model the difference δr between these two distances:

[0060] δr=||S||+||k||-||L||≈||k||-e s k;

[0061] where e s is the unit vector of satellite movement, which can be obtained from the satellite's ephemeris. It can be concluded that as long as we estimate the indoor vector k, we can recover the correct satellite-receiver direct distance from the measured satellite-metasurface-receiver refraction distance.

[0062] The indoor vector k is estimated by the difference between two adjacent measurements in time, and the two consecutive measurements ρ t+1 and ρ t Subtracting, then:

[0063] δρ t =||L t+1 ||-||L t ||+δr t+1 -δr t ;

[0064] Substituting the formula for modeling the difference δr between the two distances, we have:

[0065] δρ t =||L t+1 ||-||L t ||+(e s,t+1 -e s,t )·k;

[0066] where ||L t+1 ||-||L t || represents the difference in the direct distance between the satellite and the receiver in the two measurements. We can get it based on the pseudo-range rate measured by GPS. The pseudo-range rate is calculated from the frequency deviation of the signal and represents the Doppler effect caused by the relative motion between the satellite and the receiver. Since the Doppler effect is not affected by the refraction path, the pseudo-range rate can directly represent ||L t+1 ||-||L t ||The difference in the direct distance. And (e s,t+1 -e s,t ) represents the direction of the satellite's motion, which can be directly calculated from the ephemeris as described above, and we get:

[0067]

[0068] where mov sat,(t→t+1)represents the trajectory of the satellite, H sat is the satellite altitude. Both of these can be calculated from the ephemeris. PRR t+1 Then it is the pseudo-range rate at time t+1, which can be directly obtained from the GPS measurement results. Since there is only unknown k in the formula, it can be directly obtained. After obtaining k, we can correct the positioning result, and we have:

[0069]

[0070] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the satellite motion direction vector is calculated based on the satellite's motion trajectory vector and the satellite altitude value at two adjacent time points.

[0071] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between a GPS receiver and a satellite at two adjacent time points, the pseudorange rate is determined based on the GPS measurement results, and the pseudorange rate is used as the difference in direct distances between the satellite at two adjacent time points.

[0072] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the indoor vector is calculated based on the following formula:

[0073]

[0074] Among them, mov sat,(t→t+1) H represents the motion trajectory vector of the satellite at two adjacent time points; sat Indicates the satellite altitude; δρ t Represents the difference in propagation distance between two adjacent time points; PRR t+1 represents the pseudorange rate at the later time point between two time points, k t Indicates the indoor vector of the previous time point between two adjacent time points of the satellite.

[0075] In some embodiments of the present invention, in the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the motion trajectory vector of the satellite at two adjacent time points among four consecutive time points, the satellite altitude value, the difference in propagation distances between two adjacent time points, and the pseudorange rate at the moment of the latter time point between each two adjacent time points are obtained, and a group of equations including three equations are jointly established to calculate the x, y, and z values ​​in the indoor vector.

[0076] In some embodiments of the present invention, it is determined whether the user is moving, and if so, step S310 is adopted, and if not, steps S321 and S322 are adopted.

[0077] Using the above scheme, this scheme uses the formula when the user does not move or assumes that the user does not move Solve the set of simultaneous equations to obtain the x, y and z values ​​of the indoor vector for positioning.

[0078] In some embodiments of the present invention, it is determined whether the user is moving based on the IMU measurement of the GPS receiver. If the user is not moving, the formula is used. If the user is determined to be in the process of moving, the following method is used for the simultaneous equations:

[0079] The step of calculating the indoor vector based on the difference in propagation distances at two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiving end and the satellite at two adjacent time points also includes:

[0080] Step S321, calculating three displacement vectors of four consecutive time points determined by the GPS receiving end;

[0081] Step S322, based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances between two adjacent time points, the pseudorange rate at the moment of the latter time point between every two adjacent time points and the three displacement vectors of the user in four consecutive time points, a set of equations including three equations is jointly established to calculate the x, y and z values ​​in the indoor vector at the first time point.

[0082] In some embodiments of the present invention, based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances at two adjacent time points, the pseudorange rate at the moment of the latter time point in each two adjacent time points, and the three-segment displacement vector of the user at four consecutive time points, a system of equations including three equations is jointly established to calculate the x, y, and z values ​​in the indoor vector at the first time point, the x, y, and z values ​​in the indoor vector at the first time point are calculated based on the following formula:

[0083]

[0084] Among them, mov sat,(t→t+1) H represents the motion trajectory vector of the satellite at two adjacent time points; sat Indicates the satellite altitude; δρ t Represents the difference in propagation distance between two adjacent time points; PRR t+1 represents the pseudorange rate at the later time point between two time points, k t Indicates the indoor vector of the satellite at the previous time point between two adjacent time points, Δk t+1 Represents the displacement vector of the satellite at two adjacent time points.

[0085] In some embodiments of the present invention, based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances at two adjacent time points, the pseudo-range rate at the moment of the latter time point in each of two adjacent time points, and the three-segment displacement vector of the user at four consecutive time points, a system of equations including three equations is simultaneously established to calculate the x, y, and z values ​​in the indoor vector at the first time point, the system of equations is expressed as:

[0086]

[0087] In order to achieve accurate positioning using the above scheme, this scheme needs to estimate the user's displacement, using a combination of the smartphone's IMU measurement and GPS Doppler measurement to estimate the user's displacement, calculating the distance of the displacement through IMU data and using Doppler to calculate the direction of the displacement. After the estimation, the indoor vector can be calculated, and the positioning can be optimized according to the above method to ensure the user's accurate positioning during displacement.

[0088] In some embodiments of the present invention, in the step of calculating the three displacement vectors of four consecutive time points determined by the GPS receiving end, IMU measurement and GPS Doppler measurement of the three displacement vectors of four consecutive time points are used.

[0089] In some embodiments of the present invention, in the step of measuring three displacement vectors at four consecutive time points using IMU measurement and GPS Doppler measurement, the value of the displacement vector measured by IMU and the direction of the displacement vector measured by GPS Doppler measurement are obtained to construct the final displacement vector.

[0090] In summary, compared with the existing methods, the proposed metasurface-based indoor GPS positioning method can be deployed at a lower cost without providing indoor GPS signal coverage. The proposed positioning algorithm can accurately locate the user without relying on any environment-related information, which improves the versatility and scalability of positioning services.

[0091] An embodiment of the present invention also provides an indoor GPS positioning system, which includes a computer device, wherein the computer device includes a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the system implements the steps implemented by the method described above.

[0092] The embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps implemented by the indoor GPS positioning method described above are implemented. The computer-readable storage medium can be a tangible storage medium, such as a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable storage disk, a CD-ROM, or any other form of storage medium known in the technical field.

[0093] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0094] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0095] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An indoor GPS positioning method, characterized in that: The steps of the method include: Determine the difference in propagation distance between two adjacent time points based on the GPS receiver; Calculate the satellite motion direction vector based on the satellite altitude and the satellite trajectory vector at two adjacent time points; Calculate an indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, wherein the indoor vector corresponds to a propagation vector from the repeater to the GPS receiver; The position of the GPS receiver is located based on the propagation vector.

2. The indoor GPS positioning method according to claim 1, characterized in that: In the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the satellite motion direction vector is calculated based on the satellite's motion trajectory vector and the satellite altitude value at two adjacent time points.

3. The indoor GPS positioning method according to claim 2, characterized in that: In the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the pseudorange rate is determined based on the GPS measurement results, and the pseudorange rate is used as the difference in direct distances between the satellite at two adjacent time points.

4. The indoor GPS positioning method according to claim 3, characterized in that: In the step of calculating the indoor vector based on the difference in propagation distances at two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the indoor vector is calculated based on the following formula: Among them, mov sat,(t→t+1) H represents the motion trajectory vector of the satellite at two adjacent time points; sat Indicates the satellite altitude; δρ t Represents the difference in propagation distance between two adjacent time points; PRR t+1 It represents the pseudorange rate at the later time point between two time points.

5. The indoor GPS positioning method according to claim 4, characterized in that: In the step of calculating the indoor vector based on the difference in propagation distances between two adjacent time points, the satellite motion direction vector and the difference in direct distances between the GPS receiver and the satellite at two adjacent time points, the satellite motion trajectory vector, the satellite altitude value, the difference in propagation distances between two adjacent time points and the pseudorange rate at the moment of the latter time point between every two adjacent time points among four consecutive time points are obtained, and a group of equations including three equations are jointly established to calculate the x, y and z values ​​in the indoor vector.

6. The indoor GPS positioning method according to claim 1, characterized in that: The step of calculating the indoor vector based on the difference in propagation distances at two adjacent time points, the satellite motion direction vector, and the difference in direct distances between the GPS receiving end and the satellite at two adjacent time points also includes: Calculating three displacement vectors of four consecutive time points determined by the GPS receiving end; Based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances between two adjacent time points, the pseudorange rate at the moment of the latter time point between every two adjacent time points and the three displacement vectors of the user in four consecutive time points, a group of equations including three equations is jointly established to calculate the x, y and z values ​​in the indoor vector at the first time point.

7. The indoor GPS positioning method according to claim 6, characterized in that: In the step of calculating the x, y, and z values ​​of the indoor vector at the first time point by jointly establishing a set of equations including three equations based on the motion trajectory vector of the satellite at two adjacent time points in four consecutive time points, the satellite altitude value, the difference in propagation distances at two adjacent time points, the pseudorange rate at the moment of the latter time point in each two adjacent time points, and the three-segment displacement vectors of the user at four consecutive time points, the x, y, and z values ​​of the indoor vector at the first time point are calculated based on the following formula: Among them, mov sat,(t→t+1) H represents the motion trajectory vector of the satellite at two adjacent time points; sat Indicates the satellite altitude; δρ t Represents the difference in propagation distance between two adjacent time points; PRR t+1 represents the pseudorange rate at the later time point between two time points, k t Indicates the indoor vector of the satellite at the previous time point between two adjacent time points, Δk t+1 Represents the displacement vector of the satellite at two adjacent time points.

8. The indoor GPS positioning method according to claim 7, characterized in that: In the step of calculating the three displacement vectors of four consecutive time points determined by the GPS receiving end, the three displacement vectors of four consecutive time points are measured by IMU measurement and GPS Doppler measurement.

9. The indoor GPS positioning method according to claim 8, characterized in that: In the step of measuring three displacement vectors at four consecutive time points using IMU measurement and GPS Doppler measurement, the value of the displacement vector measured by IMU and the direction of the displacement vector measured by GPS Doppler measurement are obtained to construct a final displacement vector.

10. An indoor GPS positioning system, characterized in that: The system includes a computer device, which includes a processor and a memory. The memory stores computer instructions. The processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the system implements the steps implemented by the method as described in any one of claims 1 to 9.

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