High-precision navigation system and method combining precise point positioning and inertial navigation system

Abstract

The present invention provides a high-precision navigation system and method combining precise point positioning and inertial navigation systems. The high-precision navigation system includes: a navigation terminal device, which includes an inertial sensor unit, a satellite positioning receiver, a processing module and a wireless transmission module, wherein the inertial sensor unit obtains inertial observation data, the satellite positioning receiver obtains satellite observation data, and the wireless transmission module transmits the satellite observation data through a wireless network. A navigation server receives the satellite observation data from the navigation terminal device, calculates the satellite navigation data of the navigation terminal device based on the satellite observation data, and transmits the satellite navigation data back to the navigation terminal device through a wireless network. In this way, the navigation terminal device in the present invention can provide high-precision navigation services at a very low cost.

Description

Technical Field

[0001] The present invention relates to the field of navigation, and in particular to a high-precision navigation system and method combining a precise point positioning system and an inertial navigation system. Background Art

[0002] The combination of Precise Point Position (PPP) and Inertial Navigation System (INS) is an effective high-precision positioning technology route for the low-cost automotive consumer market. PPP is based on the multi-band Global Navigation Satellite System (GNSS) and high-precision satellite state space correction (SSR), and is widely used in the field of real-time high-precision positioning. However, the continuity and reliability of this high-precision GNSS positioning will be significantly reduced in harsh observation environments, resulting in incorrect judgments by the autonomous driving system. INS is based on inertial sensor units for navigation, which is not affected by external signals or occlusions, and can overcome the disadvantages of PPP. Since the errors of the gyroscopes and accelerometers in the inertial sensor units will accumulate over time, the accuracy of INS will also decrease significantly over time. The combined system of PPP and INS overcomes the defects of a single system by combining the observation values ​​of GNSS and INS, and improves positioning accuracy, reliability and availability. However, the implementation of the combined system of PPP and INS in low-cost terminals will face the following difficulties:

[0003] 1) SSR correction data is generally broadcast via the L-band of communication satellites or wireless networks. When satellite signal observation conditions are poor, the reception of SSR correction data will be affected;

[0004] 2) The navigation terminal equipment must support the communication satellite L-band decoding protocol and Ntrip protocol, RTCM (Radio Technical Commission for Maritime Services) information format, SSR correction data decoding and the corresponding orbit, clock error and pseudo-range phase deviation calculation. The commonly used RTCM3 data packet types and contents are shown in the following table:

[0005]

[0006]

[0007] 3) Complex data processing algorithms such as PPP-related error correction calculations, ambiguity fixation, and Kalman filtering require a lot of computing power and power consumption;

[0008] 4) Due to the limitation of the number of signal channels, the current low-cost GNSS receivers cannot guarantee the number of dual-frequency observation values ​​while ensuring multiple systems, and cannot eliminate the influence of ionospheric delay through dual-frequency ionosphere-independent combination.

[0009] 5) Correct fixation of ambiguity plays a vital role in PPP convergence. For survey-grade GNSS receivers, PPP technology usually takes 15-30 minutes to converge to the positioning accuracy requirement of unmanned driving technology, which is within 10 cm horizontally. For low-cost equipment, fixation of ambiguity will be more difficult, so the convergence time of PPP and the accuracy after convergence are core issues that need to be solved urgently. Traditional ambiguity fixation usually uses the LAMBDA method to perform ambiguity decorrelation and integer ambiguity search after the floating-point ambiguity reaches a certain accuracy. Two sets of integer ambiguity combinations are obtained and ratio detection is performed. If the detection is passed, it is considered that the optimal ambiguity combination can be fixed. But in fact, some tiny ambiguity deviations may lead to failure to pass the ratio detection, making PPP positioning unable to converge. Summary of the invention

[0010] The object of the present invention is to provide a high-precision navigation system and method combining precise point positioning and an inertial navigation system, which can enable low-cost navigation terminal equipment to provide reliable high-precision navigation services.

[0011] To achieve the purpose of the invention, according to one aspect of the invention, the invention provides a high-precision navigation system combining a precise point positioning and an inertial navigation system, comprising: a navigation terminal device, comprising an inertial sensor unit, a satellite positioning receiver, a processing module and a wireless transmission module, wherein the inertial sensor unit obtains inertial observation data, wherein the inertial observation data comprises acceleration sensor data and angular velocity sensor data, wherein the processing module calculates the acceleration sensor data and the angular velocity sensor data to obtain an inertial position change amount and an inertial velocity change amount, obtains a current inertial position based on a previous inertial position and an inertial position change amount, and obtains a current inertial velocity based on a previous inertial velocity and an inertial velocity change amount, wherein the satellite positioning receiver obtains satellite observation data, wherein the satellite observation data comprises a pseudorange observation value, a phase observation value and a Doppler observation value, and wherein the wireless transmission module transmits the satellite The satellite observation data is transmitted through a wireless network; a navigation server receives the satellite observation data from the navigation terminal device, calculates the satellite navigation data of the navigation terminal device based on the satellite observation data, and transmits the satellite navigation data back to the navigation terminal device through a wireless network, wherein the satellite navigation data includes a satellite navigation position and a satellite navigation speed, wherein a processing module of the navigation terminal device uses the satellite navigation position as a reference and combines the current inertial position to obtain a current combined navigation position, and uses the satellite navigation speed as a reference and combines the current inertial navigation speed to obtain a current combined navigation speed, wherein a sample rate of the satellite observation data is lower than a sample rate of the inertial observation data, wherein the sample rate of the satellite observation data refers to the number of satellite observation data obtained per second, and the sample rate of the inertial observation data refers to the number of inertial observation data obtained per second.

[0012] According to another aspect of the present invention, the present invention provides a high-precision navigation method combining a precise point positioning and an inertial navigation system, which comprises: an inertial sensor unit of a navigation terminal device obtains inertial observation data, wherein the inertial observation data comprises acceleration sensor data and angular velocity sensor data; a processing module of the navigation terminal device calculates the acceleration sensor data and the angular velocity sensor data to obtain an inertial position change amount and an inertial velocity change amount, obtains a current inertial position based on a previous inertial position and an inertial position change amount, and obtains a current inertial velocity based on a previous inertial velocity and an inertial velocity change amount; a satellite positioning receiver of the navigation terminal device obtains satellite observation data, wherein the satellite observation data comprises a pseudorange observation value, a phase observation value and a Doppler observation value; a wireless transmission module of the navigation terminal device transmits the satellite observation data via a wireless network send out; the navigation server receives the satellite observation data from the navigation terminal device, calculates the satellite navigation data of the navigation terminal device based on the satellite observation data, and transmits the satellite navigation data back to the navigation terminal device through a wireless network, wherein the satellite navigation data includes a satellite navigation position and a satellite navigation speed, wherein the processing module of the navigation terminal device uses the satellite navigation position as a reference and combines the current inertial position to obtain the current combined navigation position, uses the satellite navigation speed as a reference and combines the current inertial navigation speed to obtain the current combined navigation speed, the sample rate of the satellite observation data is lower than the sample rate of the inertial observation data, the sample rate of the satellite observation data refers to the number of satellite observation data obtained per second, and the sample rate of the inertial observation data refers to the number of inertial observation data obtained per second.

[0013] Compared with the prior art, the navigation terminal device in the present invention can provide high-precision navigation services at a very low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the structure of a high-precision navigation system in one embodiment of the present invention;

[0015] Figure 2 A schematic diagram of the structure of a navigation terminal device in an embodiment of the present invention;

[0016] Figure 3 FIG. 1 is a schematic diagram of the structure of a navigation server in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0018] The present invention provides a high-precision navigation system that combines precise point positioning and an inertial navigation system. Based on this architecture, the high-precision navigation system can run on a low-cost (e.g., $50) navigation terminal device, thereby providing reliable high-precision navigation services, such as positioning accuracy within 10 centimeters, thereby supporting autonomous driving navigation.

[0019] Figure 1 FIG. 1 is a schematic diagram of the structure of a high-precision navigation system 100 of the present invention in one embodiment. The high-precision navigation system 100 includes a navigation terminal device 102 and a navigation server 106 .

[0020] There may be a plurality of navigation terminal devices 102. The navigation terminal device 102 may be installed on a motor vehicle to perform high-precision navigation for the driving navigation of the motor vehicle, especially unmanned driving. The navigation terminal device 102 may communicate with the navigation server 106 via a wireless network 104. The wireless network 104 may be a 2G, 3G, 4G or 5G network, or a combination of multiple networks, such as Bluetooth + 4G, Wifi + 4G, Wifi + Internet + 5G, etc. The present invention has no requirements for the specific type of the wireless network 104, as long as it can support stable communication.

[0021] Figure 2 1 is a schematic diagram of the structure of the navigation terminal device 102 in one embodiment of the present invention. The navigation terminal device 102 includes an inertial sensing unit 210, a satellite positioning receiver 220, a processing module 230 and a wireless transmission module 240. The inertial sensing unit 210 obtains inertial observation data. The inertial sensing unit 210 includes an acceleration sensor 211 and a gyroscope 212, and the inertial observation data includes acceleration sensing data obtained by the acceleration sensor 211 and angular velocity sensing data obtained by the gyroscope 212. The processing module 230 calculates the acceleration sensing data and the angular velocity sensing data to obtain the inertial position change δp r and the inertial velocity change δv r , based on the previous inertial position and the change in inertial position δp r Get the current inertial position based on the previous inertial velocity and the inertial velocity change δv r The satellite positioning receiver 220 obtains satellite observation data, which includes pseudorange observation values, phase observation values ​​and Doppler observation values.

[0022] In one embodiment, the wireless transmission module 230 transmits the satellite observation data through the wireless network 104. The navigation terminal device 102 may be a device encapsulated in a box, or two or more devices encapsulated in two or more independent boxes, which work together to achieve the function of the navigation terminal device 102. In implementation, the wireless transmission module 240 may be located in the same box as other modules, or in a different box from other modules.

[0023] The navigation server 106 receives satellite observation data from the navigation terminal device 102, calculates satellite navigation data of the navigation terminal device 102 based on the satellite observation data, and transmits the satellite navigation data back to the navigation terminal device 102 via the wireless network 104. The satellite navigation data includes satellite navigation position and satellite navigation speed.

[0024] The processing module 230 of the navigation terminal device 102 uses the satellite navigation position as a reference and combines it with the current inertial position to obtain the current combined navigation position, and uses the satellite navigation speed as a reference and combines it with the current inertial navigation speed to obtain the current combined navigation speed. The sample rate of the satellite observation data is lower than the sample rate of the inertial observation data. The sample rate of the satellite observation data refers to the number of satellite observation data obtained per second, and the sample rate of the inertial observation data refers to the number of inertial observation data obtained per second. Specifically, the sample rate of the satellite observation data is usually 1-10, that is, 1-10 satellite observation data are obtained per second, such as 1, and the sample rate of the inertial observation data is 50-1000, that is, 50-1000 inertial observation data are obtained per second, such as 100.

[0025] In a preferred embodiment, the wireless transmission module 240 also transmits the inertial observation data to the navigation server 106 via a wireless network. At this time, the navigation server 106 calculates the satellite navigation data of the navigation terminal device 102 by combining the inertial observation data and the satellite observation data. In another alternative embodiment, the wireless transmission module 240 also transmits the inertial position change and the inertial velocity change to the navigation server 106 via a wireless network. The navigation server 106 calculates the satellite navigation data of the navigation terminal device 102 by combining the inertial position change, the inertial velocity change and the satellite observation data. The navigation server 104 can also obtain attitude information based on the inertial observation data, or the inertial position change and the inertial velocity change. The navigation server 104 also transmits the attitude information back to the navigation terminal device 102 for navigation.

[0026] Since the PPP / INS combined positioning core algorithm is implemented on the navigation server 106, the navigation terminal device 102 only needs to transmit the observation data back to the navigation server 106 through the wireless network, and after the navigation server 106 completes the calculation, the final satellite navigation data will be transmitted back to the navigation server 106. In this way, the navigation terminal device 102 does not involve positioning-related calculations and subsequent large-volume data processing, so the computing power and power consumption requirements of the navigation terminal device can be greatly reduced, and the cost of the navigation terminal device 102 can be reduced as much as possible.

[0027] The high-precision navigation system 100 of the present invention can be used for autonomous driving, and can also be used for other high-precision navigation applications.

[0028] The high-precision navigation system 100 can support four systems: GPS, GLONASS, GALILLEO and BEIDOU.

[0029] In one embodiment, the navigation server 106 obtains the satellite navigation data of the navigation terminal device 102 by the following calculation based on the inertial position change, the inertial velocity change and the satellite observation data. Figure 3 FIG. 1 is a schematic diagram of the structure of the navigation server 106 in one embodiment of the present invention.

[0030] The PPP observation model is as follows:

[0031]

[0032]

[0033]

[0034] In formulas (1), (2) and (3), P, L and D represent GNSS pseudorange, phase and Doppler observations respectively; subscripts j and s are frequency and satellite PRN number respectively; p is position; v is velocity; c is speed of light; t is clock error; r is receiver; d is pseudorange deviation; u is phase deviation; T is tropospheric delay; I is ionospheric delay; N is ambiguity. △P and △L are the various error corrections of pseudorange and phase. ε is the observation error.

[0035] For GPS, GLONASS, GALILLEO and BEIDOU systems, the PPP model state parameters are:

[0036]

[0037] The observation model of INS is:

[0038]

[0039]

[0040]

[0041] In formulas (5)-(7), S g and S a are the coefficient errors of the gyroscope and accelerometer respectively; B g and B a are the zero bias of the gyroscope and accelerometer respectively. and are the theoretical and actual angular velocity observations, respectively; and f b represent the theoretical and actual acceleration observations, respectively; is the conversion matrix from INS coordinate system to navigation coordinate system; is the angular velocity of the inertial system relative to the ECEF coordinate system; is the ECEF coordinate system relative to the navigation coordinate system; g n is the gravitational acceleration in the navigation coordinate system. is the rate of change of velocity, position and coordinate transformation matrix. According to formula (7), we can get δp r ,δv r So as to get the current position speed:

[0042] p r,INS =p r,k-1 +δp r,k (8)

[0043] v r,INS =v r,k-1 +δv r,k (9)

[0044]

[0045]

[0046] In a preferred embodiment, the navigation server 106 interactively detects the high-precision satellite state space correction SSR correction data based on the satellite observation data sent by multiple navigation terminal devices to correct the high-precision satellite state space correction. The navigation server interactively detects the satellite navigation data of one or more navigation terminal devices against the satellite navigation data of another navigation terminal device. The specific application scenarios are as follows: 1) Based on the ionosphere model, if the position of a terminal device in the area converges, the ionosphere oblique delay corresponding to the observation value of the device can be calculated to detect and correct the ionosphere model; 2) If it is found that another terminal device is near a terminal device and the data is transmitted back to the server, it can directly switch from the precise point positioning mode to the RTK (Real time kinematic) model to speed up the convergence of position information.

[0047] In a preferred embodiment, the navigation server receives SSR correction data in RTCM format from other data sources, and calculates the satellite navigation data of the navigation terminal device based on the SSR correction data and satellite observation data in RTCM format from the navigation terminal device.

[0048] In one embodiment, in order to reduce costs, the navigation terminal device 102 can only provide single-frequency satellite observation data, and the navigation server 106 needs to estimate the ionospheric delay in the process of calculating the satellite navigation data of the navigation terminal device 102 based on the satellite observation data. Preferably, the navigation server 106 uses the global ionospheric model as a correction when estimating the ionospheric delay to estimate the ionospheric oblique delay and constrain it to estimate the ionospheric delay, so as to ensure the positioning accuracy and convergence time of the precise point positioning.

[0049] The method of using the global ionosphere model as a correction, estimating the ionosphere oblique delay and constraining it is specifically as follows:

[0050]

[0051]

[0052] Where vtec is the number of ionospheric electrons in the vertical direction; N and M are the order and magnitude of the ionospheric spherical harmonics, respectively; C nm and S nm are the coefficients of spherical harmonics respectively; λs is the longitude of the mean sun fixed point; is the latitude of the ionospheric piercing point; κ j is the frequency coefficient; is the ionospheric projection coefficient, P nm is an integer-order Legendre function.

[0053] The ionospheric delay constraint function is,

[0054]

[0055] In one embodiment, the navigation server 106 needs to perform ambiguity fixation in the process of calculating the satellite navigation data of the navigation terminal device 102 based on the satellite observation data. The navigation server 106 adopts the integer ambiguity weighted average strategy when the ambiguity is fixed, and uses the LAMBDA method to perform ambiguity decorrelation and integer ambiguity combination search after the floating point ambiguity reaches a predetermined accuracy, and calculates the weight of the ambiguity combination according to the residual square sum of the searched integer ambiguity and its corresponding floating point ambiguity, obtains the optimal n groups of ambiguity combinations and their weights to calculate the weighted average ambiguity, and directly fixes it if the interpolation of the weighted average ambiguity and the integer is less than a predetermined threshold, such as 0.001.

[0056] In one embodiment, the navigation terminal device 102 sends the satellite observation data to the navigation server 106 in rtcm3 format at a frequency of 1 Hz. The navigation terminal device 102 calculates the δp in formulas (8) and (9) by using formulas (5)-(7). r ,δv r Send to the navigation server.

[0057] The navigation server receives and decodes satellite observation data, broadcasts ephemeris, SSR corrections and calculates various GNSS error corrections required for PPP.

[0058] The corresponding information can be obtained after decoding through RTCM3. Except for the satellite orbit and clock error, the specific corrections corresponding to other information can be found in formulas (1)-(3).

[0059] The RTCM3 orbit and clock correction information is as follows:

[0060] Δ SSR (IODE,t0)=(δO r ,δO a ,δO c ,δO' r ,δO' a ,δO' c ,C0,C1,C2) (15)

[0061]

[0062]

[0063] In formulas (15)-(17), δO r ,δO a ,δOc ,δO' r ,δO' a ,δO' c , C0, C1, C2 are the radial, tangential and normal orbit corrections and the rate of change of correction numbers, clock corrections and the correction rate and acceleration respectively.

[0064] δt=C0+C1(t-t0)+C2(t-t0) 2 (18)

[0065] Δt s =Δt b -δt / c (19)

[0066] Then, the user position, speed, time, attitude information, GNSS-related status information (atmospheric error, floating-point ambiguity, etc.) and INS-related status information (accelerometer and gyroscope bias and scale factor, etc.) are calculated and obtained through formulas (1)-(14). After obtaining reliable floating-point ambiguity, the above-mentioned integer ambiguity weighted average strategy is used to update the ambiguity. The result after the ambiguity update is obtained.

[0067] According to another aspect of the present invention, the present invention can be implemented as a high-precision navigation method that combines precise point positioning and inertial navigation systems. The high-precision navigation method includes: the inertial sensor unit of the navigation terminal device obtains inertial observation data, and the inertial observation data includes acceleration sensor data and angular velocity sensor data; the processing module of the navigation terminal device calculates the acceleration sensor data and angular velocity sensor data to obtain the inertial position change and the inertial velocity change, obtains the current inertial position based on the previous inertial position and the inertial position change, and obtains the current inertial velocity based on the previous inertial velocity and the inertial velocity change; the satellite positioning receiver of the navigation terminal device obtains satellite observation data, and the satellite observation data includes pseudorange observation values, phase observation values, and Doppler observation values; the wireless transmission module of the navigation terminal device transmits the satellite observation data through a wireless network; the navigation server receives the satellite observation data from the navigation terminal device; The invention relates to satellite observation data of a terminal device, satellite navigation data of the navigation terminal device is calculated based on the satellite observation data, and the satellite navigation data is transmitted back to the navigation terminal device through a wireless network, wherein the satellite navigation data includes a satellite navigation position and a satellite navigation speed, wherein the processing module of the navigation terminal device uses the satellite navigation position as a reference and combines the current inertial position to obtain a current combined navigation position, and uses the satellite navigation speed as a reference and combines the current inertial navigation speed to obtain a current combined navigation speed, wherein the sample rate of the satellite observation data is lower than the sample rate of the inertial observation data, the sample rate of the satellite observation data refers to the number of satellite observation data obtained per second, and the sample rate of the inertial observation data refers to the number of inertial observation data obtained per second.

[0068] For the relevant implementation details of the high-precision navigation method, please refer to the high-precision navigation system mentioned above, which will not be repeated here.

[0069] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0070] In this document, the directional words such as front, back, top, and bottom are defined by the positions of the components in the drawings and the positions of the components relative to each other, and are only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application.

[0071] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision navigation system combining precise point positioning and inertial navigation system, characterized in that: It includes: A navigation terminal device, comprising an inertial sensing unit, a satellite positioning receiver, a processing module and a wireless transmission module, wherein the inertial sensing unit obtains inertial observation data, wherein the inertial observation data includes acceleration sensing data and angular velocity sensing data, wherein the processing module calculates the acceleration sensing data and the angular velocity sensing data to obtain an inertial position change amount and an inertial velocity change amount, obtains a current inertial position based on a previous inertial position and an inertial position change amount, and obtains a current inertial velocity based on a previous inertial velocity and an inertial velocity change amount, wherein the satellite positioning receiver obtains satellite observation data, wherein the satellite observation data includes a pseudorange observation value, a phase observation value and a Doppler observation value, and wherein the wireless transmission module transmits the satellite observation data through a wireless network; The navigation server receives the satellite observation data from the navigation terminal device, calculates the satellite navigation data of the navigation terminal device based on the satellite observation data, and transmits the satellite navigation data back to the navigation terminal device via a wireless network, wherein the satellite navigation data includes a satellite navigation position and a satellite navigation speed. The processing module of the navigation terminal device uses the satellite navigation position as a reference and combines the current inertial position to obtain the current integrated navigation position, uses the satellite navigation speed as a reference and combines the current inertial navigation speed to obtain the current integrated navigation speed, the sample rate of the satellite observation data is lower than the sample rate of the inertial observation data, the sample rate of the satellite observation data refers to the number of satellite observation data obtained per second, and the sample rate of the inertial observation data refers to the number of inertial observation data obtained per second, The navigation server needs to perform ambiguity fixation in the process of calculating the satellite navigation data of the navigation terminal device based on the satellite observation data. The navigation server adopts an integer ambiguity weighted average strategy when the ambiguity is fixed, uses a LAMBDA method to perform ambiguity decorrelation and integer ambiguity combination search after the floating-point ambiguity reaches a predetermined accuracy, and calculates the weight of the ambiguity combination according to the residual square sum of the searched integer ambiguity and its corresponding floating-point ambiguity, obtains the optimal n groups of ambiguity combinations and their weights to calculate the weighted average ambiguity, and directly fixes the weighted average ambiguity if the difference between the weighted average ambiguity and the integer is less than a predetermined threshold. The navigation terminal device can only provide single-frequency satellite observation data, and the navigation server needs to estimate the ionospheric delay in the process of calculating the satellite navigation data of the navigation terminal device based on the satellite observation data. The navigation server uses the global ionosphere model as a correction when estimating the ionosphere delay to estimate the ionosphere oblique direction delay and constrain it to estimate the ionosphere delay to ensure the positioning accuracy and convergence time of the precise point positioning. The method of using the global ionosphere model as a correction, estimating the ionosphere oblique delay and constraining it is specifically as follows: Wherein, the subscripts j and s are the frequency and satellite PRN number respectively; I is the ionospheric delay; vtec is the number of ionospheric electrons in the vertical direction; N and M are the ionospheric spherical harmonics series and order respectively; C nm and S nm are the coefficients of spherical harmonics respectively; λs is the longitude of the mean sun fixed point; is the latitude of the ionospheric piercing point; κ j is the frequency coefficient; is the ionospheric projection coefficient, P nm is an integer-order Legendre function, The ionospheric delay constraint function is, 2. The high-precision navigation system according to claim 1, characterized in that: The wireless transmission module further transmits the inertial observation data to the navigation server via a wireless network, and the navigation server calculates the satellite navigation data of the navigation terminal device by combining the inertial observation data and the satellite observation data, or, The wireless transmission module also transmits the inertial position change and the inertial velocity change to the navigation server via a wireless network. The navigation server calculates the satellite navigation data of the navigation terminal device by combining the inertial position change, the inertial velocity change and the satellite observation data.

3. The high-precision navigation system according to claim 2, characterized in that: The navigation server obtains attitude information according to the inertial observation data.

4. The high-precision navigation system according to claim 1, characterized in that: The navigation terminal device is installed on a motor vehicle, and the navigation terminal device performs driving navigation on the motor vehicle according to the current combined navigation position and the current combined navigation speed.

5. The high-precision navigation system according to claim 1, characterized in that: The sampling rate of the satellite observation data is 1-10, and the sampling rate of the inertial observation data is 50-1000.

6. The high-precision navigation system according to claim 1, characterized in that: The navigation server interactively detects the high-precision satellite state space correction based on the satellite observation data sent by the plurality of navigation terminal devices to correct the high-precision satellite state space correction; and / or The navigation server interactively detects the satellite navigation data of another navigation terminal device based on the satellite navigation data of one or more navigation terminal devices.

7. The high-precision navigation system according to claim 1, characterized in that: The navigation server receives SSR correction data in RTCM format from other data sources, and calculates satellite navigation data of the navigation terminal device based on the SSR correction data and satellite observation data in RTCM format from the navigation terminal device.

8. A high-precision navigation method combining precise point positioning and inertial navigation system, characterized in that: It includes: The inertial sensing unit of the navigation terminal device obtains inertial observation data, wherein the inertial observation data includes acceleration sensing data and angular velocity sensing data. The processing module of the navigation terminal device calculates the acceleration sensing data and the angular velocity sensing data to obtain an inertial position change amount and an inertial velocity change amount, obtains a current inertial position based on a previous inertial position and the inertial position change amount, and obtains a current inertial velocity based on a previous inertial velocity and the inertial velocity change amount; The satellite positioning receiver of the navigation terminal device obtains satellite observation data, wherein the satellite observation data includes pseudorange observation values, phase observation values ​​and Doppler observation values; The wireless transmission module of the navigation terminal device transmits the satellite observation data through a wireless network; The navigation server receives the satellite observation data from the navigation terminal device, calculates the satellite navigation data of the navigation terminal device based on the satellite observation data, and transmits the satellite navigation data back to the navigation terminal device via a wireless network, wherein the satellite navigation data includes a satellite navigation position and a satellite navigation speed. The processing module of the navigation terminal device uses the satellite navigation position as a reference and combines the current inertial position to obtain the current integrated navigation position, uses the satellite navigation speed as a reference and combines the current inertial navigation speed to obtain the current integrated navigation speed, the sample rate of the satellite observation data is lower than the sample rate of the inertial observation data, the sample rate of the satellite observation data refers to the number of satellite observation data obtained per second, and the sample rate of the inertial observation data refers to the number of inertial observation data obtained per second, The navigation server needs to perform ambiguity fixation in the process of calculating the satellite navigation data of the navigation terminal device based on the satellite observation data. The navigation server adopts an integer ambiguity weighted average strategy when the ambiguity is fixed, uses a LAMBDA method to perform ambiguity decorrelation and integer ambiguity combination search after the floating-point ambiguity reaches a predetermined accuracy, and calculates the weight of the ambiguity combination according to the residual square sum of the searched integer ambiguity and its corresponding floating-point ambiguity, obtains the optimal n groups of ambiguity combinations and their weights to calculate the weighted average ambiguity, and directly fixes the weighted average ambiguity if the difference between the weighted average ambiguity and the integer is less than a predetermined threshold. The navigation terminal device can only provide single-frequency satellite observation data, and the navigation server needs to estimate the ionospheric delay in the process of calculating the satellite navigation data of the navigation terminal device based on the satellite observation data. The navigation server uses the global ionosphere model as a correction when estimating the ionosphere delay to estimate the ionosphere oblique direction delay and constrain it to estimate the ionosphere delay to ensure the positioning accuracy and convergence time of the precise point positioning. The method of using the global ionosphere model as a correction, estimating the ionosphere oblique delay and constraining it is specifically as follows: Wherein, the subscripts j and s are the frequency and satellite PRN number respectively; I is the ionospheric delay; vtec is the number of ionospheric electrons in the vertical direction; N and M are the ionospheric spherical harmonics series and order respectively; C nm and S nm are the coefficients of spherical harmonics respectively; λs is the longitude of the mean sun fixed point; is the latitude of the ionospheric piercing point; κ j is the frequency coefficient; is the ionospheric projection coefficient, P nm is an integer-order Legendre function, The ionospheric delay constraint function is:

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