A method to improve the dynamic adaptability of moving-to-moving differential positioning
By expanding the Doppler capture frequency offset and GF combination method, the capture and tracking of dynamic differential positioning of dynamic countermeasures under high-speed operation of the carrier is solved, and precise positioning is achieved under high dynamic conditions, meeting the positioning accuracy requirements under high-speed motion.
Patent Information
- Application Number
- CN202510603599.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2045-05-12
AI Technical Summary
In the prior art, under the high-speed operation of carriers, conventional dynamic differential positioning cannot be properly positioned and solved, and cannot effectively capture and track navigation satellite signals, resulting in insufficient positioning accuracy.
The expanded Doppler capture frequency offset method is used to capture satellite navigation signals, combined with carrier phase accumulation and pseudocode phase accumulation, the GF combination method is used to detect and eliminate the pseudorange measurement value and carrier phase measurement value in the round-hopping measurement value and coarse difference, and Kalman filtering is used to calculate parameter estimation and ambiguity fixation to achieve dynamic differential positioning under high dynamic conditions.
Under the high-speed movement of the carrier, normal capture and tracking of navigation satellite signals is achieved, effectively avoiding positioning errors caused by signal distortion, and meeting the accuracy requirements of dynamic differential positioning at high speeds.
Smart Images
Figure CN120122124B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of satellite navigation, and in particular relates to a method for improving the dynamic adaptability of moving-to-moving differential positioning. Background Art
[0002] In practical work, we often need to accurately measure the distance between two carriers to obtain the distance between the two carriers. Commonly used methods include laser ranging or radar ranging, but these methods are usually costly, bulky, and inconvenient to use and install.
[0003] Due to cost and installation considerations, the more commonly used method later was to use navigation satellite signals to perform dynamic-to-dynamic carrier phase differential positioning technology for two carriers. When the two carriers are moving at high speed, it involves measuring the relative distance between the two carriers moving under high dynamic conditions. Figure 2 As shown, the following steps are included: Capturing satellite navigation signals under high-dynamic conditions: When the carrier moves at high speed, it will have a large relative speed with the navigation satellite. For the carrier, the navigation signal will produce a Doppler frequency shift that is large relative to the original signal frequency. When capturing the navigation signal, it is necessary to capture the navigation signal with a larger Doppler frequency shift range. Tracking satellite navigation signals under high-dynamic conditions: After the carrier completes the capture of the satellite navigation signal under high-dynamic conditions, it is necessary to continue to track and process the navigation signal to solve the pseudo-range measurement value and carrier phase measurement value in the signal. Dynamic-to-dynamic differential positioning under high-dynamic conditions: After the carrier captures and tracks the satellite navigation signal under high-dynamic conditions, it uses the original observation information after signal tracking processing to perform dynamic-to-dynamic differential positioning.
[0004] In existing technologies, dynamic-to-dynamic differential positioning is primarily used in scenarios where speeds vary slowly. However, when a carrier needs to operate at high speeds, conventional dynamic-to-dynamic differential positioning cannot properly perform positioning calculations. Because the carrier needs to travel at such high speeds, it generates a large relative velocity relative to the navigation satellites. This relative velocity causes a significant frequency shift in the satellite navigation signal relative to the carrier, making it difficult for conventional receivers to properly capture and track a signal with such a large frequency shift. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned existing technologies and provide a method for improving the dynamic adaptability of move-to-move differential positioning. Under the condition of high-speed operation of the carrier, the method can normally capture and process navigation satellite signals, track and process them, and perform move-to-move differential positioning with an accuracy that meets the requirements of use.
[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, the method comprising the following steps: step S1, when the carrier is moving at high speed, adopting a method of expanding the Doppler capture frequency offset to capture the satellite navigation signal; step S2, entering the carrier tracking and pseudo code tracking process, in the carrier tracking process, performing carrier phase accumulation; in the pseudo code tracking loop, performing pseudo code phase accumulation; outputting pseudo range measurement values and carrier phase measurement values; step S3, performing data preprocessing of cycle slip detection and gross error elimination on the pseudo range measurement values and carrier phase measurement values, and then performing dynamic-to-dynamic differential positioning under high dynamic conditions.
[0007] The above-mentioned method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, in step S1, the specific process of using the method of expanding the Doppler capture frequency offset to capture satellite navigation signals when the carrier moves at high speed is as follows: step S101, assigning a value to the capture device with a Doppler frequency offset value of , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, execute step S102; step S102, assign a value to the capture device to increase the Doppler frequency deviation value , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, execute step S103; step S103, assign a value to the capture device to increase the Doppler frequency deviation value Perform the capture operation. If the capture is successful, execute step S104. If the capture fails, return to execute step S102. Step S104, tracking process. The above method of improving the dynamic adaptability of dynamic differential positioning, in steps S101 to S103 The value is 1kHz.
[0008] In the above-mentioned method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, the cycle slip detection and gross error elimination of the pseudorange measurement values and the carrier phase measurement values in step S3 are performed using a GF (geometry-free) combination method.
[0009] In the above-mentioned method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, the specific process of using the GF (geometry-free) combination method to detect cycle slips and eliminate gross errors in the pseudorange measurement values and carrier phase measurement values in step S3 is as follows: Step A1, establishing a dual-frequency pseudorange ionospheric residual model and a dual-frequency carrier phase ionospheric residual model, which can be expressed as: ,in, is the pseudorange measurement value of two adjacent epochs and Do badly, is the phase measurement value of two adjacent carriers and Step A2, the dual-frequency pseudo-range ionosphere residual model and the dual-frequency carrier phase ionosphere model are combined by GF to obtain , expressed as: ,in, for conduct The polynomial generated after the order polynomial fitting, Equivalent to , expressed as: ,in, is the wavelength of frequency 1, is the integer ambiguity of frequency 1, is the wavelength of frequency 2, is the integer ambiguity of frequency 2; Step A3, through the two adjacent epochs Perform subtraction to determine the cycle slips and gross errors of the satellite navigation signal carrier phase measurement value.
[0010] The above method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning is as follows: When making a difference and determining the cycle slip and gross error of the satellite navigation signal carrier phase measurement value, the formula is expressed as: ,in, and are all constant coefficients. In cycle slip detection, when both equations (F5) and (F6) hold true, it is determined that the satellite signal currently participating in the solution has a cycle slip. When only equation (F5) is satisfied, it is determined that a gross error has occurred in the measurement of the current satellite signal. When it is determined that a gross error or a cycle slip has occurred in the measurement of the current satellite signal, the current satellite signal is removed from the solution process, and the solution is continued using the remaining satellite signals.
[0011] The above method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning is as follows: The value of is 6.
[0012] The above method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning is as follows: The value of is 1.
[0013] The above-mentioned method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, as described in step S3, performs dynamic-to-dynamic differential positioning under high-dynamic conditions, and the specific process is: step S301, establishes a carrier relative positioning mathematical model, and establishes a pseudo-range relative positioning mathematical model; step S302, performs filter parameter estimation on both the carrier relative positioning mathematical model and the pseudo-range relative positioning mathematical model; step S303, performs ambiguity fixation on the carrier relative positioning mathematical model to obtain a fixed solution; step S304, performs residual check on the carrier relative positioning mathematical model and the pseudo-range relative positioning mathematical model, outputs the result when the check passes, and returns to step S301 when the check fails. The above-mentioned method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, as described in step S303, adopts the Kalman filter parameter estimation method when performing filter parameter estimation.
[0014] Compared with the prior art, the present invention has the following advantages: when the carrier moves at high speed, the present invention uses the expanded Doppler capture frequency offset to capture the satellite navigation signal; when the carrier moves at high speed, the observation quantity GF combination is used to detect the carrier phase cycle jump, thereby avoiding the positioning error caused by the distortion of the high-speed movement signal, and can meet the demand for dynamic-to-dynamic differential positioning of the carrier in the case of high-speed movement to output the accurate relative position.
[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a flowchart of the method of the present invention; Figure 2 This is a flow chart of the dynamic-to-dynamic differential positioning process under high dynamic conditions of the present invention; Figure 3 This is a flowchart of the present invention for capturing satellite navigation signals; Figure 4 This is a diagram showing the processing of Doppler frequency deviation of satellite navigation signals under high carrier speed conditions in the present invention; Figure 5 This is a schematic diagram of the satellite navigation signal tracking loop of the present invention; Figure 6 This is a flow chart of the dynamic-to-dynamic differential positioning solution of the present invention; Figure 7 This is a flow chart of carrier phase signal cycle slip detection in the present invention; Figure 8 This is a graph showing the measurement accuracy of the baseline length between two carriers on the X-axis, Y-axis, and Z-axis of the present invention; Figure 9 This is a curve diagram of the three-axis composite measurement accuracy of the baseline length between two carriers of the present invention. DETAILED DESCRIPTION
[0017] like Figure 1As shown, the method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning of the present invention includes the following steps: Step S1, when the carrier moves at high speed, a method of expanding the Doppler capture frequency offset is used to capture the satellite navigation signal; when capturing and processing the satellite navigation signal under high dynamic conditions, the frequency search range of the satellite navigation signal to be captured is expanded to achieve the capture of the signal by the carrier under high-speed motion conditions; Figure 3 As shown in the figure, searching for the signal that generates the Doppler frequency shift in the next frequency domain range is a key step. When capturing satellite navigation signals, special processing is required for high-speed motion scenarios. When the carrier is moving at a low speed, a wide range of capture frequency shifts is not required for signal capture. However, when the carrier is moving at a high speed, a larger Doppler frequency shift is required for signal capture.
[0018] In this embodiment, the specific process of capturing satellite navigation signals by using the method of expanding Doppler capture frequency offset when the carrier moves at high speed in step S1 is as follows: step S101, assigning a value to the capture device with a Doppler frequency offset value of , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, execute step S102; step S102, assign a value to the capture device to increase the Doppler frequency deviation value , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, execute step S103; step S103, assign a value to the capture device to increase the Doppler frequency deviation value , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, return to execute step S102; step S104, tracking processing. In this embodiment, steps S101 to S103 The value is 1kHz.
[0019] Take capturing the high-speed moving No. 1 satellite navigation signal as an example, Figure 4As shown, the specific process of capturing satellite navigation signals by using the method of expanding Doppler capture frequency offset is as follows: step S101, assigning a Doppler frequency offset value of 1kHz for satellite navigation signal No. 1 to the capturer, capturing satellite navigation signal No. 1, and when the capture is successful, executing step S104; when the capture fails, executing step S102; step S102, assigning a Doppler frequency offset value of 1kHz increased by the frequency offset of satellite navigation signal No. 1 to the capturer, capturing satellite navigation signal No. 1, and when the capture is successful, executing step S104; when the capture fails, executing step S103; step S103, assigning a Doppler frequency offset value of 1kHz increased by the frequency offset of satellite navigation signal No. 1 to the capturer, capturing satellite navigation signal No. 1, and when the capture is successful, executing step S104; when the capture fails, returning to executing step S102; step S104, tracking satellite navigation signal No. 1.
[0020] In a specific implementation, when the maximum capture Doppler frequency deviation is set to 6 kHz, the maximum moving speed of the carrier can be met to be 7000 m / s.
[0021] Step S2: After the signal is captured, the carrier tracking and pseudo code tracking process begins. Figure 5 As shown, the Doppler frequency estimation value and pseudo code phase estimation value output by the capture module are used to quickly set the carrier NCO and code NCO, so that the tracking channel quickly enters the carrier tracking and pseudo code tracking process. In the carrier tracking process, the carrier phase is accumulated; in the pseudo code tracking loop, the pseudo code phase is accumulated; when the loop is locked, the data bit synchronization and frame synchronization clock are extracted, and the pseudo range measurement value and carrier phase measurement value are output; step S3, as shown Figure 6 As shown, after data preprocessing for cycle slip detection and gross error removal on the pseudorange and carrier phase measurements, dynamic-to-dynamic differential positioning is performed under high dynamic conditions. In this embodiment, the cycle slip detection and gross error removal of the pseudorange and carrier phase measurements in step S3 are performed using a GF (geometry-free) combination method.
[0022] In this embodiment, when performing cycle slip detection and gross error elimination on the pseudorange measurement value and the carrier phase measurement value in step S3, the specific process of using the GF (geometry-free) combination method is as follows: Step A1, establishing a dual-frequency pseudorange ionospheric residual model and a dual-frequency carrier phase ionospheric residual model, which can be expressed as: ,in, is the pseudorange measurement value of two adjacent epochs and Do badly, is the phase measurement value of two adjacent carriers and Step A2, the dual-frequency pseudo-range ionosphere residual model and the dual-frequency carrier phase ionosphere model are combined by GF to obtain , expressed as: ,in, for conduct The polynomial generated after the order polynomial fitting, Equivalent to , expressed as: ,in, is the wavelength of frequency 1, is the integer ambiguity of frequency 1, is the wavelength of frequency 2, is the integer ambiguity of frequency 2; Step A3, through the two adjacent epochs Perform subtraction to determine the cycle slips and gross errors of the satellite navigation signal carrier phase measurement value.
[0023] In this embodiment, the step A3 is performed by the two adjacent epochs. When making a difference and determining the cycle slip and gross error of the satellite navigation signal carrier phase measurement value, the formula is expressed as: ,in, Indicates the epochs, Indicates the epochs, Indicates the epochs, and are all constant coefficients.
[0024] In the cycle slip detection, when equations (F5) and (F6) are both true, it is determined that the satellite signal currently involved in the solution has a cycle slip phenomenon; when only equation (F5) is satisfied, it is determined that a gross error has occurred in the measurement of the current satellite signal; when it is determined that a gross error or a cycle slip has occurred in the measurement of the current satellite signal, the current satellite signal is removed from the solution process and the solution is continued using the remaining satellite signals; the judgment process is as follows: Figure 7 shown.
[0025] In this embodiment, the The value of is 6. That is, formula (F5) is expressed as: .
[0026] In this embodiment, the The value of is 1. That is, formula (F6) is expressed as: .
[0027] In this embodiment, the specific process of performing dynamic-to-dynamic differential positioning under high dynamic conditions described in step S3 is as follows: step S301, establishing a carrier relative positioning mathematical model, and establishing a pseudorange relative positioning mathematical model; step S302, performing filter parameter estimation on both the carrier relative positioning mathematical model and the pseudorange relative positioning mathematical model; step S303, fixing the ambiguity of the carrier relative positioning mathematical model to obtain a fixed solution; step S304, performing residual check on the carrier relative positioning mathematical model and the pseudorange relative positioning mathematical model, and outputting the result when the check passes, and returning to step S301 when the check fails.
[0028] Using moving-to-moving differential positioning technology, two devices serve as the base station and rover, respectively. The base station calculates its own position using pseudoranges and sends these coordinates to the rover as the base station coordinates. Due to the high-speed motion of the carrier, satellite navigation signals may experience signal interruption, signal loss, and signal distortion. When a lost signal is recaptured, a cycle slip may occur. When a cycle slip occurs, it must be specially processed to eliminate its impact on differential positioning.
[0029] The present invention uses the observation quantity GF combination to detect carrier phase cycle slips when the carrier moves at high speed, which can effectively avoid positioning errors caused by high-speed moving signal distortion.
[0030] Step S302: Establish a carrier-relative positioning mathematical model and a pseudo-range relative positioning mathematical model. Step S303: Estimate filter parameters for both the carrier-relative positioning mathematical model and the pseudo-range relative positioning mathematical model. In this embodiment, the Kalman filter parameter estimation method is used for the filter parameter estimation described in step S303. Step S304: Fix the ambiguity of the carrier-relative positioning mathematical model to obtain a fixed solution. Step S305: Perform residual check on the carrier-relative positioning mathematical model and the pseudo-range relative positioning mathematical model. If the check passes, output the result. If the check fails, return to step S301.
[0031] In order to verify the technical effect of the present invention, a navigation signal source is used to simulate two carriers moving at high speed to perform dynamic-to-dynamic differential positioning. The baseline measurement accuracy is obtained by subtracting the measured relative distance from the relative distance benchmark of the simulation source. The satellite navigation simulation source sets the test scenario as two carriers with a speed of 7000m / s and a distance of 24km between them. The broadcast signals are BDS B1 and BDS B3. The test results are as follows: Figure 8 and Figure 9 The test results show that the three-axis composite error of the measured relative distance is 0.036m (1σ), which meets the requirements of dynamic-to-dynamic differential positioning of the carrier at high speed.
[0032] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.
Claims
1. A method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning, characterized in that: The method comprises the following steps: Step S1, when the carrier moves at high speed, the method of expanding the Doppler capture frequency offset is used to capture the satellite navigation signal; the specific process of the method of expanding the Doppler capture frequency offset is as follows: Step S101, assigning a value to the capture device with a Doppler frequency offset value of , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, execute step S102; step S102, assign a value to the capture device to increase the Doppler frequency deviation value , perform the capture operation, if the capture is successful, execute step S104; if the capture fails, execute step S103; step S103, assign a value to the capture device to increase the Doppler frequency deviation value , perform capture operation, when capture is successful, execute step S104; when capture fails, return to execute step S102; step S104, tracking processing; step S2, enter carrier tracking and pseudo code tracking process, in the carrier tracking process, perform carrier phase accumulation; in the pseudo code tracking loop, perform pseudo code phase accumulation; output pseudo range measurement value and carrier phase measurement value; step S3, perform data preprocessing for cycle slip detection and gross error elimination on the pseudo range measurement value and carrier phase measurement value, and then perform dynamic-to-dynamic differential positioning under high dynamic conditions; when performing cycle slip detection and gross error elimination on the pseudo range measurement value and carrier phase measurement value in step S3, the specific process of using the GF combination method is as follows: step A1, establish a dual-frequency pseudo range ionosphere residual model and a dual-frequency carrier phase ionosphere residual model, expressed as: ,in, is the pseudorange measurement value of two adjacent epochs and Do badly, is the phase measurement value of two adjacent carriers and Step A2, the dual-frequency pseudo-range ionosphere residual model and the dual-frequency carrier phase ionosphere model are combined by GF to obtain , expressed as: ,in, for The polynomial generated after N-order polynomial fitting, Equivalent to , expressed as: ,in, is the wavelength of frequency 1, is the integer ambiguity of frequency 1, The wavelength of frequency 2, is the integer ambiguity of frequency 2; Step A3, through the two adjacent epochs Make a difference and determine the cycle slip and gross error of the satellite navigation signal carrier phase measurement value; Step A3 is described by the two adjacent epochs When determining the cycle slip and gross error of the satellite navigation signal carrier phase measurement value, the formula is expressed as: ,in, and are all constant coefficients; The value of is 6; The value of is 1; In cycle slip detection, when both equations (F5) and (F6) hold true, the satellite signal currently involved in the solution is determined to have a cycle slip. When only equation (F5) holds true, a gross error has occurred in the current satellite signal measurement. When a gross error or a cycle slip has occurred in the current satellite signal measurement, the current satellite signal is removed from the solution process and the solution is continued using the remaining satellite signals.
2. A method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning according to claim 1, characterized in that: In steps S101 to S103 The value is 1kHz.
3. A method for improving dynamic adaptability of dynamic-to-dynamic differential positioning according to claim 1, characterized in that: When performing cycle slip detection and gross error elimination on the pseudorange measurement values and the carrier phase measurement values in step S3, the GF combination method is used.
4. A method for improving dynamic adaptability of dynamic-to-dynamic differential positioning according to claim 1, characterized in that: The specific process of performing dynamic-to-dynamic differential positioning under high dynamic conditions as described in step S3 is as follows: step S301, establishing a carrier relative positioning mathematical model, and establishing a pseudorange relative positioning mathematical model; step S302, performing filter parameter estimation on both the carrier relative positioning mathematical model and the pseudorange relative positioning mathematical model; step S303, fixing the ambiguity of the carrier relative positioning mathematical model to obtain a fixed solution; step S304, performing residual check on the carrier relative positioning mathematical model and the pseudorange relative positioning mathematical model, and outputting the result when the check passes, and returning to step S301 when the check fails.
5. A method for improving the dynamic adaptability of dynamic-to-dynamic differential positioning according to claim 4, characterized in that: When performing the filter parameter estimation in step S303, a Kalman filter parameter estimation method is adopted.