Unmanned aerial vehicle positioning method, device and system during signal interruption, and storage medium

Abstract

The invention discloses an unmanned aerial vehicle positioning method, device and system during signal interruption, and a storage medium. The method comprises the following steps: receiving a broadcast ephemeris broadcasted by a satellite, observation value data and a real-time orbital clock error correction number; judging whether the real-time orbital clock error correction is interrupted or not; if the real-time orbital clock error correction is interrupted, performing short-term forecasting on the correction by establishing a quartic polynomial; combining the correction number with the broadcast ephemeris to generate a real-time precise ephemeris and a real-time track; if the predicted correction number is used, an observation equation is established through epoch difference to settle a coordinate difference; if the received correction number is used, an observation equation is established through a PPP model, and the real-time coordinates of the unmanned aerial vehicle are settled. By adopting the technical scheme of the invention, high-precision positioning of the unmanned aerial vehicle during short-term signal interruption is realized.

Description

Technical Field

[0001] This invention belongs to the field of satellite positioning technology, specifically relating to a method, device, system, and storage medium for locating unmanned aerial vehicles (UAVs) when signals are interrupted. Background Technology

[0002] In weak network environments, UAV positioning faces the problem of reduced satellite positioning accuracy. Due to the inability to obtain real-time orbit correction data, positioning errors may reach the meter level. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a method, device, system, and storage medium for locating unmanned aerial vehicles (UAVs) when signals are interrupted.

[0004] To achieve the above objectives, the present invention provides the following solution: A method for locating a drone when a signal is interrupted includes: Step 1: Receive broadcast ephemeris data, observation data, and real-time position corrections from the satellite; Step 2: Determine if the real-time track clock correction is interrupted; Step 3: If the real-time orbital clock error correction is interrupted, a short-term forecast of the correction is made by establishing a quartic polynomial. Step 4: Combine the corrections with the broadcast ephemeris to generate real-time precise orbits and clock biases; Step 5: If the received corrections are used, establish the observation equations through the PPP model and calculate the real-time coordinates of the UAV. Step 6: If the predicted corrections are used, calculate the coordinate differences by establishing observation equations through interepoch differences.

[0005] As a preferred method, real-time satellite orbit clock corrections are obtained through SSR to achieve real-time high-precision positioning.

[0006] Preferably, in step four, by performing IOD matching between the broadcast ephemeris and the real-time satellite orbit corrections, the broadcast ephemeris is corrected using the orbit corrections to generate a precise orbit for use in PPP and epoch difference; by performing IOD matching between the broadcast ephemeris and the real-time satellite clock error corrections, the broadcast ephemeris is corrected using the clock error corrections to generate a precise clock error for use in PPP and epoch difference.

[0007] The present invention also provides a drone positioning device when the signal is interrupted, comprising: The first processing module is used to receive broadcast ephemeris data, observation data and real-time position corrections transmitted by the satellite; The second processing module is used to determine whether the real-time track clock correction is interrupted; The third processing module is used to make a short-term forecast of the correction value by establishing a quartic polynomial if the real-time orbital clock error correction value is interrupted. The fourth processing module is used to combine the corrections with the broadcast ephemeris to generate real-time precise orbits and clock errors; The fifth processing module is used to establish observation equations through the PPP model and calculate the real-time coordinates of the UAV if the received corrections are used. The sixth processing module is used to calculate the coordinate difference by establishing an observation equation through inter-epoch difference if the predicted correction is used.

[0008] As a preferred method, real-time satellite orbit clock corrections are obtained through SSR to achieve real-time high-precision positioning.

[0009] Preferably, the fourth processing module generates a precise orbit for PPP and epoch difference by performing IOD matching between the broadcast ephemeris and the real-time satellite orbit correction, and corrects the broadcast ephemeris using the orbit correction; at the same time, it generates a precise clock error for PPP and epoch difference by performing IOD matching between the broadcast ephemeris and the real-time satellite clock error correction, and corrects the broadcast ephemeris using the clock error correction.

[0010] The present invention also provides a drone positioning system when a signal is interrupted, comprising: a memory and a processor, wherein the memory stores a computer program executed by the processor, and the computer program executes a drone positioning method when the signal is interrupted when the processor runs.

[0011] The present invention also provides a storage medium storing a computer program, which executes a UAV positioning method when a signal is interrupted during operation.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves high-precision positioning of UAVs during short-term signal interruptions by performing short-term forecasts of SSRs, obtaining the forecasted broadcast ephemeris, and eliminating forecast errors of orbit and clock bias between adjacent epochs by subtracting the observation values ​​between adjacent epochs and establishing observation equations, and calculating the coordinate changes between adjacent epochs. Attached Figure Description

[0013] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1This is a flowchart of the UAV positioning method when the signal is interrupted according to an embodiment of the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Example 1 like Figure 1 As shown, the present invention provides a method for locating a drone when a signal is interrupted, comprising: Step 1: Receive broadcast ephemeris data, observation data, and real-time position corrections from the satellite; Step 2: Determine if the real-time track clock correction is interrupted; Step 3: If the real-time orbital clock error correction is interrupted, a short-term forecast of the correction is made by establishing a quartic polynomial. Step 4: Combine the corrections with the broadcast ephemeris to generate real-time precise orbits and clock biases; Step 5: If the received corrections are used, establish the observation equations through the PPP model and calculate the real-time coordinates of the UAV. Step 6: If the predicted corrections are used, calculate the coordinate differences by establishing observation equations through interepoch differences.

[0018] In one embodiment of the present invention, in step three, if the real-time orbital clock error correction is interrupted, a short-term forecast of the correction is made by establishing a fourth-degree polynomial, including: (1) Search for all historical orbit clock corrections that have the same IOD as the current broadcast ephemeris.

[0019] (2) A fourth-order polynomial prediction is established for the searched IODs, and the formula is as follows: In the formula, Represents the stored SSR, Represents the time of storage. , , , , The polynomial coefficients represent the estimated values. SSR representing the forecast, This represents the predicted time.

[0020] In one embodiment of the present invention, step four involves merging the correction number with the broadcast ephemeris to generate real-time precise orbits and clock errors, including: (1) Calculate the correction in the star-fixed coordinate system at the current moment, using the following formula: In the formula, Representing the current moment, The reference time representing the satellite orbital correction. The number representing the correction to the current satellite orbit. The radial, normal, and tangential corrections to the satellite's orbit at the reference time. The radial, normal, and tangential velocity corrections for the satellite orbit at the reference time are given, where... .

[0021] (2) The formula for converting the satellite's orbital correction from the star-fixed coordinate system to the geocentric Earth-fixed coordinate system is as follows: In the formula, Represents the orbital correction of the satellite in the geocentric-ground-fixed coordinate system. The satellite position represents the value calculated from the broadcast ephemeris. The satellite velocity represented by the broadcast ephemeris calculation. The unit vector representing the direction of the satellite, where, . (3) Correct the satellite's orbital values ​​to the satellite orbit calculated from the broadcast ephemeris to obtain the real-time precise orbit. The formula is as follows: In the formula, The precise orbit representing a satellite, The satellite orbit representing the broadcast ephemeris calculation.

[0022] (4) Calculate the satellite clock error correction at the current time using the following formula: In the formula, The clock error correction value representing the current moment. Representing the current moment, The reference time representing the clock error correction. The polynomial coefficients represent the clock error correction, where, .

[0023] (5) Correct the satellite clock error to the satellite clock error calculated from the broadcast ephemeris to obtain the real-time precise clock error. The formula is as follows: In the formula, The precision clock bias representing the satellite, Satellite clock bias representing broadcast ephemeris calculations, Represents the speed of light in vacuum.

[0024] In one embodiment of the present invention, in step five, if the received correction values ​​are used, an observation equation is established through the PPP model to calculate the real-time coordinates of the UAV, i.e. In the formula, Represents pseudorange observations. Represents carrier phase observations, Represents the geometric distance between the satellite and the receiver. represents the speed of light in vacuum, Represents receiver clock bias. Represents satellite clock bias, Represents tropospheric delay error. This represents the hardware delay of the code pseudorange between the receiver antenna and the signal. This represents the hardware delay of the code pseudorange between the satellite signal transmitter and the satellite antenna. This represents the pseudorange measurement error. Represents the carrier wavelength. Represents the overall ambiguity throughout the week. This represents the phase hardware delay of the receiver. Represents the phase hardware delay at the satellite end. This represents the carrier phase measurement error.

[0025] In one embodiment of the present invention, in step six, if the predicted correction is used, the coordinate difference is calculated by establishing an observation equation through inter-epoch difference, that is, In the formula, Represents the difference in carrier waves between adjacent epochs. , , Represents the satellite position at the previous moment. , , Satellite coordinates representing the current moment. , , This represents the receiver position at the previous moment. Satellite clock bias representing the current moment, The satellite clock difference representing the previous moment, , , This represents the coordinate difference between two epochs. This represents the difference in receiver clock bias between two epochs.

[0026] Example 2 The present invention also provides a drone positioning device when the signal is interrupted, comprising: The first processing module is used to receive broadcast ephemeris data, observation data and real-time position corrections transmitted by the satellite; The second processing module is used to determine whether the real-time track clock correction is interrupted; The third processing module is used to make a short-term forecast of the correction value by establishing a quartic polynomial if the real-time orbital clock error correction value is interrupted. The fourth processing module is used to combine the corrections with the broadcast ephemeris to generate real-time precise orbits and clock errors; The fifth processing module is used to establish observation equations through the PPP model and calculate the real-time coordinates of the UAV if the received corrections are used. The sixth processing module is used to calculate the coordinate difference by establishing an observation equation through inter-epoch difference if the predicted correction is used.

[0027] As one embodiment of the present invention, real-time satellite orbit clock corrections are obtained through SSR to achieve real-time high-precision positioning.

[0028] In one embodiment of the present invention, the fourth processing module performs IOD matching on the broadcast ephemeris and real-time satellite orbit corrections, corrects the broadcast ephemeris using the orbit corrections, and generates a precise orbit for use in PPP and epoch difference; simultaneously, it performs IOD matching on the broadcast ephemeris and real-time satellite clock error corrections, and generates a precise clock error for use in PPP and epoch difference.

[0029] Example 3 The present invention also provides a drone positioning system when a signal is interrupted, comprising: a memory and a processor, wherein the memory stores a computer program executed by the processor, and the computer program executes a drone positioning method when the signal is interrupted when the processor runs.

[0030] Example 4 The present invention also provides a storage medium storing a computer program, which, when running, executes a UAV positioning method when a signal is interrupted. The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for locating a UAV when a signal is interrupted, characterized in that, include: Step 1: Receive broadcast ephemeris data, observation data, and real-time position corrections from the satellite; Step 2: Determine if the real-time track clock correction is interrupted; Step 3: If the real-time orbital clock error correction is interrupted, a short-term forecast of the correction is made by establishing a quartic polynomial. Step 4: Combine the corrections with the broadcast ephemeris to generate real-time precise orbits and clock biases; Step 5: If the received corrections are used, establish the observation equations through the PPP model and calculate the real-time coordinates of the UAV. Step 6: If the predicted corrections are used, calculate the coordinate differences by establishing observation equations through interepoch differences.

2. The UAV positioning method when signal interruption occurs as described in claim 1, characterized in that, Real-time high-precision positioning can be achieved by obtaining real-time satellite orbit clock correction values ​​through SSR.

3. The UAV positioning method when signal interruption occurs as described in claim 2, characterized in that, In step four, precise orbits are generated by matching the broadcast ephemeris and real-time satellite orbit corrections using IOD to generate precise clock errors for PPP and epoch-to-epoch differential calculations, and the broadcast ephemeris is corrected using the orbit corrections.

4. A drone positioning device for signal interruption, characterized in that, include: The first processing module is used to receive broadcast ephemeris data, observation data and real-time position corrections transmitted by the satellite; The second processing module is used to determine whether the real-time track clock correction is interrupted; The third processing module is used to make a short-term forecast of the correction value by establishing a quartic polynomial if the real-time orbital clock error correction value is interrupted. The fourth processing module is used to combine the corrections with the broadcast ephemeris to generate real-time precise orbits and clock errors; The fifth processing module is used to establish observation equations through the PPP model and calculate the real-time coordinates of the UAV if the received corrections are used. The sixth processing module is used to calculate the coordinate difference by establishing an observation equation through inter-epoch difference if the predicted correction is used.

5. The UAV positioning device for signal interruption as described in claim 4, characterized in that, Real-time high-precision positioning can be achieved by obtaining real-time satellite orbit clock correction values ​​through SSR.

6. The UAV positioning device for signal interruption as described in claim 5, characterized in that, The fourth processing module performs IOD matching between broadcast ephemeris and real-time satellite orbit corrections, uses the orbit corrections to correct the broadcast ephemeris, and generates precise orbits for PPP and epoch difference. Simultaneously, it performs IOD matching between broadcast ephemeris and real-time satellite clock error corrections, uses the clock error corrections to correct the broadcast ephemeris, and generates precise clock errors for PPP and epoch difference.

7. A UAV positioning system for signal interruption, characterized in that, include: A memory and a processor, wherein the memory stores a computer program executed by the processor, the computer program executing, when run by the processor, the UAV positioning method as described in any one of claims 1-3.

8. A storage medium, characterized in that, The storage medium stores a computer program, which, when running, executes the UAV positioning method for signal interruption as described in any one of claims 1-3.

Images