Indoor GPS positioning method and system

Abstract

The application provides an indoor GPS positioning method and system, and the steps of the method comprise the following steps: determining the difference of propagation distances of two adjacent time points based on a GPS receiving end; calculating a satellite motion direction vector based on a satellite height and a trajectory vector of the satellite at two adjacent time points; calculating an indoor vector based on the difference of the propagation distances of two adjacent time points, the satellite motion direction vector and the difference of direct distances between the GPS receiving end and the satellite at two adjacent time points, the indoor vector corresponding to a propagation vector from a repeater to the GPS receiving end; and positioning the position of the GPS receiving end based on the propagation vector. The scheme models the calculation of the indoor vector in advance, estimates the indoor vector through the difference of two adjacent measurements in time, and can determine the indoor vector and complete indoor positioning without determining the position of the repeater in advance.

Description

TECHNICAL FIELD

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

[0002] Global Positioning System (GPS), also known as Global Satellite Positioning System, is a medium-orbit satellite navigation system. It can provide accurate positioning, speed measurement and high-precision standard time for most areas on the earth. Global Positioning System can meet the needs of users at any place on the earth or near-earth space to continuously and accurately determine three-dimensional position, three-dimensional motion 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, and GPS receivers, smart phones and the like as user terminals. A minimum of only four satellites can quickly determine the position 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 is positioned by time difference, it can also accurately correct the time stamp. GPS system has the following advantages: using low-frequency signals, even in bad weather, the signal penetration remains relatively high; global coverage of up to 98%; high-precision three-dimensional speed and time; fast, time-saving and efficient; widely used and multifunctional; mobile positioning. Due to high availability and universality, most navigation and synchronization applications are completed using GPS.

[0003] Although GPS performs very high robustness in outdoor environments, it is almost impossible to use in indoor scenarios. First, the LoS signal of the satellite is difficult to penetrate obstacles such as walls or iron sheds, and the existing indoor positioning method needs to determine the position of the repeater, and then constructs an indoor vector based on the position of the repeater and the GPS receiving end of the user, and then performs positioning through the indoor vector, so the positioning adaptability of the prior art is poor. SUMMARY

[0004] In view of this, the embodiments of the present application provide 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 application provides an indoor GPS positioning method, the steps of which include:

[0006] determining the difference in propagation distance between two adjacent time points based on the GPS receiving end;

[0007] calculating a satellite motion direction vector based on the satellite height and the trajectory vector of the satellite at two adjacent time points;

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

[0009] position the GPS receiver based on the propagation vector.

[0010] With the above scheme, in the positioning scheme, since the distance value measured by the GPS receiver is actually the sum of the distance from the satellite to the repeater and the distance from the repeater to the GPS receiver, the indoor vector is modeled in advance, the estimation of the indoor vector is completed through the difference between two adjacent time points, and the indoor vector is determined without determining the position of the repeater in advance, and the indoor positioning is completed.

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

[0012] In some embodiments of the present application, in the step of calculating the indoor vector based on the difference between the propagation distances of two adjacent time points, the satellite motion direction vector and the difference between the direct distances between the GPS receiver and the satellite of two adjacent time points, the pseudo-range rate is determined based on the measurement result of the GPS, and the pseudo-range rate is used as the difference between the direct distances between the GPS receiver and the satellite of two adjacent time points.

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

[0014]

[0015] wherein, mov sat,(t→t+1) represents the satellite trajectory vector of two adjacent time points of the satellite; H sat represents the satellite height value; δρ t represents the difference between the propagation distances of two adjacent time points; PRR t+1 represents the pseudo-range rate at the time of the later time point of the two time points, k t represents the indoor vector of the former time point of two adjacent time points of the satellite.

[0016] In some embodiments of the present application, in the step of calculating the indoor vector based on the difference of the propagation distances of two adjacent time points, the satellite motion direction vector and the difference of the direct distances between the GPS receiver and the satellite of two adjacent time points, the motion trajectory vector of the satellite of two adjacent time points in the four continuous time points, the satellite elevation value, the difference of the propagation distances of two adjacent time points and the pseudorange rate at the time of the later time point in each two adjacent time points are obtained, and a set of equations including three equations are solved to calculate the x, y and z values in the indoor vector.

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

[0018] calculating three displacement vectors of the GPS receiver at the four continuous time points;

[0019] solving a set of equations including three equations based on the motion trajectory vector of the satellite of two adjacent time points in the four continuous time points, the satellite elevation value, the difference of the propagation distances of two adjacent time points, the pseudorange rate at the time of the later time point in each two adjacent time points and the three displacement vectors of the user at the four continuous time points to calculate the x, y and z values in the indoor vector at the first time point.

[0020] In some embodiments of the present application, in the step of solving a set of equations including three equations based on the motion trajectory vector of the satellite of two adjacent time points in the four continuous time points, the satellite elevation value, the difference of the propagation distances of two adjacent time points, the pseudorange rate at the time of the later time point in each two adjacent time points and the three displacement vectors of the user at the four continuous time points 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] wherein, mov sat,(t→t+1) represents the motion trajectory vector of the satellite of two adjacent time points; H sat represents the satellite elevation value; δρ t represents the difference of the propagation distances of two adjacent time points; PRR t+1 represents the pseudorange rate at the time of the later time point in two time points, k t represents the indoor vector at the former time point of two adjacent time points of the satellite, Δk t+1 represents the displacement vector of the satellite of two adjacent time points.

[0023] In some embodiments of the present application, in the step of calculating the x, y and z values in the indoor vector at the first time point based on the motion trajectory vectors of the satellites at the adjacent two time points among the four consecutive time points, the satellite elevation values at the adjacent two time points, the difference of the propagation distances at the adjacent two time points, the pseudorange rate at the time point of the later one of each two adjacent time points and the three-segment displacement vectors of the user at the four consecutive time points, the simultaneous equations including three equations are expressed as:

[0024]

[0025] In some embodiments of the present application, in the step of calculating the three-segment displacement vectors of the user at the four consecutive time points, the three-segment displacement vectors at the four consecutive time points are measured by the IMU and the Doppler measurement of the GPS.

[0026] In some embodiments of the present application, in the step of calculating the three-segment displacement vectors at the four consecutive time points by the IMU measurement and the Doppler measurement of the GPS, the values in the displacement vectors measured by the IMU and the directions in the displacement vectors measured by the Doppler measurement of the GPS are obtained to construct the final displacement vectors.

[0027] The second aspect of the present application further provides an indoor GPS positioning system, which comprises a computer device, the computer device comprising a processor and a memory, the memory storing computer instructions, and the processor being configured to execute the computer instructions stored in the memory, so that the system implements the steps as implemented by the foregoing method.

[0028] The third aspect of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps as implemented by the foregoing indoor GPS positioning method.

[0029] Additional advantages, objects, and features of the application will be set forth in part by the description that follows, and will in part be apparent to those of ordinary skill in the art upon examination of the following or can be learned from practice of the application. The objectives and other advantages of the application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0030] It will be understood by those skilled in the art that the objects and advantages of the present application can be realized and attained by the means set forth in the written description and claims hereof as well as the appended drawings, without being limited to the above specifically described aspects and embodiments. The objects and other advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.

[0032] Figure 1 A schematic diagram of an embodiment of the indoor GPS positioning method according to the present application;

[0033] Figure 2 A schematic diagram of another embodiment of the indoor GPS positioning method according to the present application;

[0034] Figure 3 A schematic diagram of the comparison between indoor positioning and outdoor positioning;

[0035] Figure 4 A schematic diagram of the existing indoor GPS positioning method;

[0036] Figure 5 A schematic diagram of the existing indoor GPS relay assisted positioning method. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and the accompanying drawings. Herein, the schematic embodiments of the present application and the descriptions thereof are used to explain the present application, but not to limit the present application.

[0038] It should be noted that, in order to avoid the present application being obscured by unnecessary details, only the structures and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, and other details not closely related to the present application are omitted.

[0039] In the prior art, although GPS shows high robustness in outdoor environment, it is almost impossible to use in indoor scenarios, because the LoS signal of satellite cannot penetrate through obstacles such as walls or iron sheds. The existing solution uses GPS relay devices with known positions to provide indoor GPS signal coverage. A typical GPS relay is connected by a pair of GPS antennas through a radio frequency cable, which realizes the coverage of the received outdoor GPS signal to the indoor, and connects with the user through another communication channel to inform the position thereof. Although there is GPS signal coverage in the indoor, the GPS signal received from the relay will introduce distance estimation error due to the NLOS signal propagation path of satellite-relay-user. The user relies on the known information of the relay position, and further positions himself by taking the relay as an anchor point. Some methods directly interact with the relay to obtain the relay position and calculate the relay-user distance, so as to directly complete the positioning with the relay as an anchor point; while other methods calculate the propagation distance difference from different relay signals by differential positioning, so as to complete the positioning. Therefore, when the relay position information is unavailable, the existing method will immediately fail. For example, as shown in the left side of FIG. 1, when the GPS user knows the indoor relay deployment position, the positioning result of the user can be corrected by this information, so as to realize accurate positioning. However, if a new user enters the scene, as shown in the right side of FIG. 1, the new user cannot obtain the relay position information, and the existing method will immediately fail. Figure 4 As shown in the left side of FIG. 1, when the GPS user knows the indoor relay deployment position, the positioning result of the user can be corrected by this information, so as to realize accurate positioning. However, if a new user enters the scene, as shown in the right side of FIG. 1, the new user cannot obtain the relay position information, and the existing method will immediately fail. Figure 4As shown in the right side of the figure, the user cannot obtain specific information of the relay position, and then the positioning accuracy sharply decreases due to the NLoS path. The applicability and scalability of the existing method are very limited.

[0040] Prior art I:

[0041] As shown in the right side of the figure, the user cannot obtain specific information of the relay position, and then the positioning accuracy sharply decreases due to the NLoS path. The applicability and scalability of the existing method are very limited. Figure 5 As shown in the right side of the figure, the user cannot obtain specific information of the relay position, and then the positioning accuracy sharply decreases due to the NLoS path. The applicability and scalability of the existing method are very limited.

[0042] The system uses indoor relay as an anchor point for positioning, and requires the receiver, i.e., the user, to understand the deployment position of the indoor relay, and to calculate the positioning coordinates of the receiver itself. If the user enters this scene for the first time and cannot understand the information of the relay deployment, the positioning will be directly invalidated.

[0043] In addition, the deployment of GPS relay requires the deployment of a receiving end in the outdoor and a transmitting end in the indoor, and the use of a cable to connect the signal to the indoor, which is very difficult to deploy.

[0044] After providing GPS signals for indoor scenes, the present scheme needs to correct the positioning of the user in the indoor scene. The previous method uses the position of the relay and the measurement data of GPS to complete the indoor positioning, which limits the availability and universality of GPS service.

[0045] As shown in the right side of the figure, the user cannot obtain specific information of the relay position, and then the positioning accuracy sharply decreases due to the NLoS path. The applicability and scalability of the existing method are very limited. Figure 1 The present application provides an indoor GPS positioning method, and the steps of the method comprise:

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

[0047] In the specific implementation process, the GPS receiving end can be a mobile terminal of the user, and can be a mobile phone, a notebook computer, a tablet computer or the like.

[0048] Step S200, calculating a satellite motion direction vector based on the satellite height 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 height is calculated as the satellite motion direction vector.

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

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

[0052] Step S400, positioning the position of the GPS receiver based on the propagation vector.

[0053] With the above scheme, in the positioning scheme of the present scheme, since the distance value that can be measured by the GPS receiver is actually the sum of the distances from the satellite to the repeater and from the repeater to the GPS receiver, the present scheme models the calculation of the indoor vector in advance, and estimates the indoor vector through the difference of two adjacent measurements in time, and the present scheme can determine the indoor vector without determining the position of the repeater in advance, and complete the indoor positioning.

[0054] In the specific implementation process, in the normal outdoor scenario, as shown in the schematic diagram of the indoor environment, the GPS receiver calculates the pseudo-range ρ by calculating the delay of its clock and the satellite clock, and calculates the distance ||L|| between the satellite and the receiver through the pseudo-range, i.e. Figure 3

[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 difference of the satellite and the GPS clock, the ionospheric delay and the tropospheric delay of the GPS signal, and the three items can be modeled and eliminated from the navigation information provided by the GPS, ∈ ρ is the pseudo-range measurement error caused by noise. In the case of known satellite coordinates (x s , y s , z s ), the equation can be established:

[0057]

[0058] From the four different above equations, i.e. the pseudo-range measurements from four different satellites, the coordinates of the receiver and the clock difference with the satellite (x, y, z, δ t ) can be calculated, and thus the positioning is completed.

[0059] And in the refraction model, the measurement result of the pseudo-range is not the direct satellite-receiver distance, but the refraction distance of satellite-super surface-receiver. As shown in Figure 3 ​As shown in the schematic diagram of the indoor-outdoor scenario, the result of the pseudo-range is not ||L||, but ||S||+||k||. The goal of this approach is to model the difference between these two distances, δr:

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

[0061] where e s is the unit vector of the satellite's movement, which can be obtained from the satellite's ephemeris. Thus, it can be concluded that as long as we estimate the indoor vector k, we can recover the correct straight-line satellite-receiver distance from the measured satellite-super-surface-receiver refracted distance.

[0062] The estimation of the indoor vector k is done by the difference between two adjacent measurements in time, by subtracting the two consecutive measurements, ρ t+1 and ρ t :

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

[0064] Bringing the formula modeling the difference between the two distances, δr, 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 straight-line satellite-receiver distance between the two measurements, which can be obtained from the GPS measured pseudo-range rate, which is calculated from the signal's frequency offset and represents the Doppler effect caused by the relative movement between the satellite and the receiver. Since the Doppler effect is not affected by the refracted path, the pseudo-range rate can directly represent the difference in the straight-line distance ||L t+1 || - ||L t ||. And (e s,t+1 - e s,t ) represents the direction of the satellite's movement, which can be directly calculated from the ephemeris as described above, resulting in:

[0067]

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

[0069]

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

[0071] In some embodiments of the present application, in the step of calculating the indoor vector based on the difference between the propagation distances of the adjacent two time points, the satellite motion direction vector and the difference between the direct distances of the GPS receiver and the satellite at the adjacent two time points, the pseudo-range rate is determined based on the measurement result of GPS, and the pseudo-range rate is taken as the difference between the direct distances of the satellite at the adjacent two time points.

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

[0073]

[0074] wherein, mov sat,(t→t+1) represents a motion trajectory of the satellite at the adjacent two time points; H sat represents a satellite height value; δρ t represents the difference between the propagation distances of the adjacent two time points; PRR t+1 represents the pseudo-range rate at the time of the later time point of the two time points, k t represents the indoor vector at the earlier time point of the satellite at the adjacent two time points.

[0075] In some embodiments of the present application, in the step of calculating the indoor vector based on the difference of the propagation distances of the two adjacent time points, the satellite motion direction vector and the difference of the direct distances between the GPS receiver and the satellite of the two adjacent time points, the motion trajectory vector of the satellite of the two adjacent time points in the four continuous time points, the satellite elevation value, the difference of the propagation distances of the two adjacent time points and the pseudo-range rate at the time of the later time point in each two adjacent time points are obtained, and a set of equations including three equations are solved to calculate the x, y and z values in the indoor vector.

[0076] In some embodiments of the present application, it is determined whether the user is moving, and if yes, step S310 is adopted, and if no, steps S321 and S322 are adopted.

[0077] With the above scheme, in the case that the user is not moving or is assumed to be not moving, the indoor vector is calculated by the formula The set of equations is solved to obtain the x, y and z values in the indoor vector, and the positioning is performed.

[0078] In some embodiments of the present application, it is determined whether the user is moving based on the IMU measurement of the GPS receiver, and if the user is not moving, the formula The set of equations is solved, and if it is determined that the user is moving, the following method is adopted:

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

[0080] Step S321, calculating three displacement vectors of the GPS receiver at the four continuous time points;

[0081] Step S322, based on the motion trajectory vector of the satellite of the two adjacent time points in the four continuous time points, the satellite elevation value, the difference of the propagation distances of the two adjacent time points, the pseudo-range rate at the time of the later time point in each two adjacent time points and the three displacement vectors of the user at the four continuous time points, a set of equations including three equations are solved to calculate the x, y and z values in the indoor vector at the first time point.

[0082] In some embodiments of the present application, in the step of calculating the x, y and z values in the indoor vector at the first time point based on the motion trajectory vector of the satellite of the two adjacent time points in the four continuous time points, the satellite elevation value, the difference of the propagation distances of the two adjacent time points, the pseudo-range rate at the time of the later time point in each two adjacent time points and the three displacement vectors of the user at the four continuous time points, a set of equations including three equations are solved to calculate the x, y and z values in the indoor vector at the first time point based on the following formula:

[0083]

[0084] wherein, mov sat,(t→t+1) denotes the satellite's motion trajectory vector of the satellite at two adjacent time points; H sat denotes the satellite's height value; δρ t denotes the difference of the propagation distance at two adjacent time points; PRR t+1 denotes the pseudo-range rate at the time point of the later one of the two time points, k t denotes the indoor vector of the satellite at the earlier one of two adjacent time points, Δk t+1 denotes the displacement vector of the satellite at two adjacent time points.

[0085] In some embodiments of the present application, in the step of calculating the x, y and z values in the indoor vector at the first time point based on the satellite's motion trajectory vector of the satellite at two adjacent time points among the continuous four time points, the satellite's height value, the difference of the propagation distance at two adjacent time points, the pseudo-range rate at the time point of the later one of each two adjacent time points and the three-segment displacement vector of the user at the continuous four time points, the simultaneous equations including three equations are represented as:

[0086]

[0087] With the above scheme, in order to realize accurate positioning, the scheme needs to estimate the displacement of the user, estimates the displacement of the user by combining the IMU measurement of the smart phone and the Doppler measurement of the GPS, calculates the distance value of the displacement by the IMU data and calculates the direction of the displacement by the Doppler. After estimation, the indoor vector can be calculated, and the positioning is optimized according to the method above, ensuring the accurate positioning of the user in the displacement.

[0088] In some embodiments of the present application, in the step of calculating the three-segment displacement vector of the continuous four time points at the GPS receiving end, the three-segment displacement vector of the continuous four time points is measured by the IMU and the Doppler of the GPS.

[0089] In some embodiments of the present application, in the step of measuring the three-segment displacement vector of the continuous four time points by the IMU and the Doppler of the GPS, the value in the displacement vector measured by the IMU and the direction in the displacement vector measured by the Doppler of the GPS are obtained, and the final displacement vector is constructed.

[0090] In summary, compared with the prior art, the indoor GPS positioning method based on the super surface can provide indoor GPS signal coverage at a lower deployment, and the positioning algorithm can complete accurate positioning of the user without relying on any environment-related information, thereby improving the universality and scalability of the positioning service.

[0091] The embodiment of the present application also provides an indoor GPS positioning system, which comprises a computer device, the computer device comprising a processor and a memory, the memory storing computer instructions, and the processor being configured to execute the computer instructions stored in the memory, so that the system implements the steps of the method as described above.

[0092] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the indoor GPS positioning method as described above. 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 disk, a CD-ROM, or any other form of storage medium known in the art.

[0093] Those skilled in the art should understand that the exemplary components, systems and methods described in connection with the embodiments disclosed herein can be implemented in hardware, software or a combination thereof. The choice of hardware or software implementation is dependent on the particular application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a functional card, etc. When implemented in software, the elements of the present application are program or code segments used to perform the required tasks. The program or code segments can be stored in a machine readable medium or transmitted through a data signal carried in a carrier wave over a transmission medium or communication link.

[0094] It should be clear that the present application is not limited to the specific configurations and processes described above and shown in the drawings. For the sake of brevity, detailed descriptions of known methods are omitted herein. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application 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 of the steps, after understanding the spirit of the present application.

[0095] Features described and / or illustrated with respect to one implementation can be used in the same manner or in a similar manner in one or more other implementations and / or in combination with or in place of features of other implementations.

[0096] The above descriptions are only the preferred embodiments of the present application, not intended to limit the present application. The embodiments of the present application can be variously changed and / or modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of the present application.

Claims

1. An indoor GPS positioning method, characterized in that, The steps of this method include: The difference in propagation distance between two adjacent time points is determined based on the GPS receiver; Calculate the satellite motion direction vector based on the satellite altitude and the trajectory vectors of two adjacent time points; The indoor vector is calculated based on the difference in propagation distance between two adjacent time points, the satellite motion direction vector, and the difference in the direct distance between the GPS receiver and the satellite between 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 the direct distance between the satellite and two adjacent time points. The indoor vector is then calculated based on the following formula: in, A vector representing the trajectory of a satellite at two adjacent points in time; Indicates the satellite's altitude value; This represents the difference in propagation distance between two adjacent time points; This represents the pseudorange rate at the later of two time points. The indoor vector represents the earlier of two adjacent time points of the satellite, and the indoor vector corresponds to the propagation vector from the repeater to the GPS receiver; The location of the GPS receiver is determined 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 distance between two adjacent time points, the satellite motion direction vector, and the difference in direct distance between the GPS receiver and the satellite between two adjacent time points, the satellite motion trajectory vector, satellite altitude value, difference in propagation distance between two adjacent time points, and pseudorange rate of the time of the next time point in each of the two adjacent time points are obtained. A system of equations including three equations is then formed to calculate the x, y, and z values ​​in the indoor vector.

3. The indoor GPS positioning method according to claim 1, characterized in that, The steps for calculating the indoor vector based on the difference in propagation distance between two adjacent time points, the satellite motion direction vector, and the difference in the direct distance between the GPS receiver and the satellite between two adjacent time points also include: The GPS receiver calculates three displacement vectors at four consecutive time points. Based on the satellite's trajectory vectors, satellite altitude values, the difference in propagation distance between two adjacent time points in four consecutive time points, the pseudorange rate of the time at the next time point in each pair of adjacent time points, and the user's three displacement vectors in four consecutive time points, a system of equations consisting of three equations is established to calculate the x, y, and z values ​​in the indoor vector at the first time point.

4. The indoor GPS positioning method according to claim 3, characterized in that, In the step of calculating the x, y, and z values ​​in the indoor vector at the first time point, based on the satellite's trajectory vector at two adjacent time points within four consecutive time points, the satellite altitude value, the difference in propagation distance between two adjacent time points, the pseudorange rate at the time of the next time point between two adjacent time points, and the user's three displacement vectors at four consecutive time points, a system of three equations is established. The x, y, and z values ​​in the indoor vector at the first time point are calculated based on the following formula: in, A vector representing the trajectory of a satellite at two adjacent points in time; Indicates the satellite's altitude value; This represents the difference in propagation distance between two adjacent time points; This represents the pseudorange rate at the later of two time points. This represents the displacement vector of a satellite at two adjacent time points.

5. The indoor GPS positioning method according to claim 4, characterized in that, In the step of calculating the three displacement vectors at four consecutive time points determined by the GPS receiver, IMU measurement and GPS Doppler measurement of the three displacement vectors at four consecutive time points are used.

6. The indoor GPS positioning method according to claim 5, characterized in that, In the step of using IMU measurement and GPS Doppler measurement to obtain three displacement vectors at four consecutive time points, the numerical values ​​of the displacement vector measured by IMU and the directions of the displacement vector measured by GPS Doppler are obtained to construct the final displacement vector.

7. 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, and the processor executes the computer instructions stored in the memory. When the computer instructions are executed by the processor, the system implements the steps of the method as described in any one of claims 1 to 6.

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