A timing system based on dual Beidou receivers and a timing accuracy analysis method

Abstract

The invention provides a timing system based on dual Beidou receivers and a timing accuracy analysis method, which relate to the technical field of timing. A pair of Beidou receivers are used to receive satellite signals and output original observation quantity messages and time messages. A SOC processor receives and processes the original observation quantity messages and time messages, and analyzes and calculates data values ​​such as carrier-to-noise ratio, elevation angle, phase residual error value, satellite PDOP information value, and number of available satellites in the messages. Subsequently, a local rubidium atomic clock is used as a reference to calculate the phase deviation value between the receiver and the rubidium atomic clock, and between the receivers. Finally, a triangular cross phase deviation comparison and analysis method is used to effectively eliminate the influence of abnormal phase jump, channel delay, internal noise and multipath effect of the receiver on the timing accuracy, and obtain phase and frequency deviation correction values, so that the timing system can automatically calibrate the system core time, correct the phase and frequency deviation, and output high-precision timing signals and frequency signals.

Description

Technical Field

[0001] The present invention relates to the technical field of timing, and in particular to a timing system based on dual Beidou receivers and a timing accuracy analysis method. Background Art

[0002] With the continuous advancement and maturity of BeiDou navigation system technology, BeiDou timing system, as an important application branch, has shown increasingly broad application potential in many key fields such as electricity, finance, railways, autonomous driving and communications. BeiDou timing system, as a high-precision time synchronization solution based on BeiDou satellite navigation system and BeiDou timing receiver, is centered on calibrating the local time signal by receiving the precise time signal broadcast by BeiDou satellites, and accurately transmitting the calibrated time signal to all devices that need to achieve time synchronization, thereby ensuring a high degree of consistency in the time of each device within the entire system.

[0003] In a distributed system architecture, the time synchronization accuracy between sites is a core indicator to measure the system's ability to coordinate work. However, although the Beidou timing system has shown great potential in high-precision time synchronization, the current technical solutions still face a series of challenges. Specifically, the existing Beidou timing technology solutions mainly receive Beidou satellite signals, measure key observables such as pseudorange and carrier phase, and then continuously adjust the frequency and phase of the receiver's local clock to achieve high-precision timing. However, since the clock element commonly used in Beidou receivers is a temperature-compensated crystal oscillator, its output accuracy is easily affected by ambient temperature fluctuations, causing the output accuracy to fluctuate with changes in ambient temperature.

[0004] In addition, due to the individual differences in the electronic components of Beidou receivers produced by different manufacturers, even if they are the same model of receivers, the timing accuracy of their outputs may vary greatly. Ideally, the phase changes of the second pulse timing signal output by the Beidou receiver should be evenly distributed around the phase center value. However, in actual applications, due to factors such as device aging or batch differences, the phase changes of the second pulse timing signal output by some Beidou receivers are not evenly distributed, but show a trend of continuous slow shift to the right or left. This phase shift phenomenon will not only affect the stability of the output signal of the timing system, but also lead to a decrease in the time synchronization accuracy performance between distributed sites, thereby affecting the coordinated operation capability of the entire system.

[0005] Therefore, how to effectively analyze and improve the inter-station synchronization accuracy of the Beidou timing system to overcome the deficiencies in existing technologies has become a technical problem that needs to be solved urgently.

[0006] Therefore, it is necessary to provide a timing system based on dual Beidou receivers and a timing accuracy analysis method to solve the above technical problems. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a timing system based on dual Beidou receivers and a timing accuracy analysis method, which can receive dual-channel Beidou signals and output high-precision timing signals after internal processing.

[0008] The present invention provides a timing system based on dual Beidou receivers, the system comprising a pair of Beidou antennas, a pair of Beidou receivers, a SOC processor, a local rubidium atomic clock and a timing signal output module, wherein:

[0009] A pair of Beidou antennas, used to receive navigation signals from Beidou satellites and transmit them to corresponding Beidou receivers, including Beidou antenna A and Beidou antenna B;

[0010] A pair of Beidou receivers, respectively connected to corresponding Beidou antennas, are used to capture and track Beidou satellite signals and output original observation message, time message and second pulse signal, including Beidou receiver A and Beidou receiver B;

[0011] A local rubidium atomic clock is used to generate a clock signal and output a frequency signal;

[0012] The SOC processor is used to receive and process the original observation message and time message, and detect the validity and time continuity of the time message. At the same time, it calculates the time phase correction value and the frequency deviation correction value through the triangular cross phase deviation comparison analysis method, and corrects the core time of the timing system to generate the corrected time signal and frequency signal;

[0013] The timing signal output module is connected to the SOC processor and is used to receive and encode the calibrated and corrected time signal and frequency signal, and finally distribute them to the device to be time synchronized.

[0014] Preferably, the SOC processor specifically performs the following steps:

[0015] The validity of the original observation message output by the Beidou receiver is tested, including the carrier-to-noise ratio, elevation angle, phase residual error value, satellite PDOP information value and number of available satellites of the Beidou satellite, and the satellite carrier-to-noise ratio threshold is set to 35dBc, the satellite elevation angle threshold is set to 15°, and the satellites with carrier-to-noise ratio and elevation angle below the threshold are eliminated;

[0016] Check the time continuity of the Beidou receiver's output time message;

[0017] Use the second pulse signal output by the Beidou receiver to compare the phase deviation with the second pulse signal generated by the local rubidium atomic clock, and obtain the phase deviation value between the local rubidium atomic clock, Beidou receiver A and Beidou receiver B;

[0018] According to the phase residual error value and the phase deviation value, the timing accuracy of the dual-channel Beidou receiver is analyzed by using a triangular cross phase deviation comparison analysis method, and a time phase correction value and a frequency deviation correction value are calculated;

[0019] According to the time phase correction value and the frequency offset correction value, the core time of the timing system is calibrated, and the time phase and frequency offset of the timing system are corrected.

[0020] Preferably, the SOC processor further includes:

[0021] Time digital converter, used to measure the time interval between the 1Hz signal generated by the local rubidium atomic clock and the second pulse signal output by Beidou receiver A and Beidou receiver B;

[0022] Specifically, the 10 MHz frequency output by the local rubidium atomic clock is divided into 1 Hz with a division ratio of 10000000:1, which is used as the Start trigger signal of the time digital converter.

[0023] The pulse-per-second signal output by Beidou receiver A is used as the Stop trigger signal of the A-th time-to-digital converter, and the pulse-per-second signal output by Beidou receiver B is used as the Stop trigger signal of the B-th time-to-digital converter;

[0024] The second pulse signal output by Beidou receiver A is used as the Start trigger signal of the C-th time digital converter, and the second pulse signal output by Beidou receiver B is used as the Stop trigger signal of the C-th time digital converter.

[0025] Preferably, the triangular cross phase deviation comparison and analysis method specifically includes:

[0026] Calculate the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal generated by the local rubidium atomic clock and calculate the phase residual error value of Beidou receiver A;

[0027] Calculate the phase deviation between the second pulse signal of Beidou receiver B and the second pulse signal generated by the local rubidium atomic clock and calculate the phase residual error value of Beidou receiver B;

[0028] Calculate the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal of Beidou receiver B;

[0029] According to the above phase deviation value, phase residual error value and the difference between the phase residual error values, determine whether there is an abnormal jump value. If the change value exceeds a preset threshold, discard the group of measurement values ​​and continue with the next group of measurements;

[0030] Record the measured values ​​within the set time, and by processing the recorded measured values, you can get the timing accuracy of Beidou receiver A and Beidou receiver B. The specific processing steps are as follows:

[0031] The first step is to calculate whether the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock and the offset of the phase deviation value between Beidou receiver B and the local rubidium atomic clock exceed the set threshold; if the offset of the phase deviation value of Beidou receiver A and Beidou receiver B exceeds the set threshold, it returns that Beidou receiver A and Beidou receiver B are both unavailable, otherwise proceed to the next step for judgment;

[0032] The second step is to compare the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock and the offset of the phase deviation value between Beidou receiver B and the local rubidium atomic clock; if the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is greater than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and the phase adjustment value of Beidou receiver B is returned; if the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is less than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and the phase adjustment value of Beidou receiver A is returned; if the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0033] The third step is to compare the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock and the discrete degree of the phase deviation value between Beidou receiver B and the local rubidium atomic clock; if the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is greater than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and the phase adjustment value of Beidou receiver B is returned; if the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is less than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and the phase adjustment value of Beidou receiver A is returned; if the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0034] The fourth step is to compare the offset of the phase deviation value of Beidou receiver A and Beidou receiver B; if the offset of the phase deviation value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the offset of the phase deviation value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the offset of the phase deviation value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0035] The fifth step is to compare the discrete degrees of the phase deviation values ​​of Beidou receiver A and Beidou receiver B; if the discrete degree of the phase deviation value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the discrete degree of the phase deviation value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the discrete degree of the phase deviation value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0036] The sixth step is to compare the offset of the phase residual error value of Beidou receiver A and Beidou receiver B; if the offset of the phase residual error value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the offset of the phase residual error value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the offset of the phase residual error value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0037] The seventh step is to compare the discrete degrees of the phase residual error values ​​of Beidou receiver A and Beidou receiver B; if the discrete degree of the phase residual error value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the discrete degree of the phase residual error value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the discrete degree of the phase residual error value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0038] Step 8. Compare the number of available satellites of Beidou receiver A and Beidou receiver B. If the number of available satellites of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A. If the number of available satellites of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B. If the number of available satellites of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment.

[0039] The ninth step is to compare the carrier-to-noise ratio of the same satellite of Beidou receiver A and Beidou receiver B; if the carrier-to-noise ratio of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the carrier-to-noise ratio of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the carrier-to-noise ratio of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment;

[0040] Step 10. Compare the PDOP values ​​of Beidou receiver A and Beidou receiver B. If the PDOP value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B. If the PDOP value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A. If the PDOP value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment.

[0041] The eleventh step is to compare the priority values ​​of Beidou receiver A and Beidou receiver B; if the priority value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the priority value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A.

[0042] Preferably, the triangular cross phase deviation comparison and analysis method further includes:

[0043] According to the timing accuracy result and the phase adjustment value, a system phase adjustment value and a system frequency adjustment control word are generated to calibrate the phase and frequency of the timing system.

[0044] Preferably, the timing signal output module performs the following steps:

[0045] receiving a calibrated and corrected time phase signal and frequency signal provided by a SOC processor;

[0046] These signals are encoded, and the encoded timing signals and frequency signals are distributed to the devices to be time synchronized.

[0047] The present invention also provides a timing accuracy analysis method based on a dual Beidou receiver, which is applied to a timing system based on a dual Beidou receiver, and the method comprises the following steps:

[0048] The Beidou receiver receives Beidou satellite signals through the Beidou antenna, captures and tracks the Beidou satellites, and then outputs the original observation message, time message, and second pulse signal.

[0049] The SOC processor receives and processes the original observation message and time message, detects the carrier-to-noise ratio, elevation angle, phase residual error value, satellite PDOP information value, and the number of available satellites of the satellite, sets the satellite carrier-to-noise ratio threshold to 35 dBc, the satellite elevation angle threshold to 15°, eliminates the satellites with carrier-to-noise ratio and elevation angle lower than the threshold, and at the same time detects the time continuity of the time message output by the Beidou receiver.

[0050] The second pulse signal output by the Beidou receiver is used to compare the phase deviation with the second pulse signal generated by the local rubidium atomic clock to obtain the phase deviation values between the local rubidium atomic clock, Beidou receiver A, and Beidou receiver B pairwise.

[0051] The time synchronization accuracy of the dual Beidou receivers is analyzed using the triangular cross-phase deviation comparison analysis method. At the same time, the phase deviation correction value and frequency deviation correction value are generated according to the time synchronization accuracy value, phase deviation value, and phase residual error value.

[0052] The core time of the time synchronization system is calibrated according to the time message. At the same time, the phase deviation correction value and frequency deviation correction value calculated by the triangular cross-phase deviation comparison analysis method are used to correct the time phase and frequency offset of the time synchronization system.

[0053] The time synchronization system outputs the time synchronization signal and frequency signal according to the corrected time phase and frequency.

[0054] Compared with the related technologies, a time synchronization system and a time synchronization accuracy analysis method based on dual Beidou receivers provided by the present invention have the following beneficial effects:

[0055] The present invention proposes a method of pairwise comparison of the signals of the dual Beidou receivers and the local rubidium atomic clock through the triangular cross-phase deviation comparison method, models the slow change trend of the second pulse of the Beidou receiver, calculates and corrects the slow change amount of the Beidou receiver by analyzing the change trend of the second pulse signal output by the receiver, and effectively improves the time synchronization accuracy of the Beidou time synchronization system. At the same time, the dual Beidou receiver time synchronization system of the present invention can eliminate the uncorrelated phase abnormal jumps through the dual receivers, and can effectively improve the time synchronization accuracy of the Beidou time synchronization system. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is the architecture diagram of a time synchronization system based on dual Beidou receivers provided by the present invention;

[0057] Figure 2 It is the working flow chart of a time synchronization system based on dual Beidou receivers provided by the present invention;

[0058] Figure 3 Schematic diagram of the triangular cross phase deviation comparison and analysis method of the present invention;

[0059] Figure 4 A flow chart of the triangular cross phase deviation comparison and analysis method of the present invention;

[0060] Figure 5 It is a schematic diagram of the structure of Beidou receiver A, Beidou receiver B and local rubidium atomic clock of the present invention;

[0061] Figure 6 It is a schematic structural diagram of the A-th time-to-digital converter, the B-th time-to-digital converter and the C-th time-to-digital converter of the present invention;

[0062] Figure 7 It is another structural schematic diagram of the A-th time-to-digital converter, the B-th time-to-digital converter and the C-th time-to-digital converter of the present invention. DETAILED DESCRIPTION

[0063] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings. In addition, the embodiments of the present invention and the features in the embodiments may be combined with each other without conflict.

[0064] It should also be noted that, for ease of description, only the parts related to the present invention, but not all of the contents, are shown in the accompanying drawings. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but it can also have additional steps not included in the accompanying drawings. The process can correspond to methods, functions, procedures, subroutines, subprograms, etc.

[0065] Embodiment 1

[0066] A timing system based on dual Beidou receivers, reference Figure 1 As shown, the system includes:

[0067] A pair of Beidou antennas, a pair of Beidou receivers, a SOC processor, a rubidium atomic clock and a timing signal output module, among which:

[0068] A pair of Beidou antennas, used to receive navigation signals from Beidou satellites and transmit them to corresponding Beidou receivers, including Beidou antenna A and Beidou antenna B.

[0069] A pair of Beidou receivers, respectively connected to corresponding Beidou antennas, are used to capture and track Beidou satellite signals and output original observation messages, time messages and second pulse signals, including Beidou receiver A and Beidou receiver B.

[0070] Rubidium atomic clock, used to generate high-precision clock signals and output high-precision frequency signals;

[0071] The SOC processor receives and processes the original observation message and time message. First, the carrier-to-noise ratio, elevation angle, phase residual error value, satellite PDOP information value, number of available satellites and other data values ​​in the message are analyzed and calculated. Then, the validity and time continuity of the time message are detected. Subsequently, the local rubidium atomic clock is used as a reference to calculate the phase deviation value between the receiver and the rubidium atomic clock, and between the receivers. Finally, the influence of abnormal phase jump of the receiver, receiver channel delay, internal noise of the receiver and multipath effect on the timing accuracy is effectively eliminated through the triangular cross phase deviation comparison analysis method, and the phase and frequency deviation correction values ​​are obtained. The timing system automatically calibrates the core time of the timing system according to the received time message, corrects the system phase and system frequency deviation through the phase and frequency deviation correction values ​​obtained by the triangular cross comparison analysis method, and outputs the high-precision time signal and frequency signal to the timing signal output module.

[0072] The timing signal output module is connected to the SOC processor and is used to receive and encode the calibrated and corrected time phase and frequency signals, and finally distribute them to the devices to be time synchronized.

[0073] More specifically, Beidou antenna module A and Beidou antenna module B are Beidou receiving antennas of the same model, which mainly realize the reception and amplification of Beidou satellite signals. Beidou antenna module mainly includes Beidou antenna oscillator, low noise amplifier, LDO voltage regulator unit, antenna cover and other key components.

[0074] Beidou receiver A and Beidou receiver B are the same model of Beidou receiver, which mainly realizes the processing of Beidou satellite signals, outputs original observation messages such as pseudorange and carrier phase, outputs NEMA-0183 messages, and outputs second pulse timing signals. Beidou receiver module mainly includes key components such as radio frequency unit, baseband processing unit, clock unit, power supply unit, etc.

[0075] The rubidium atomic clock is the core unit of the timing system, which mainly generates high-accuracy and high-stability clock signals. At the same time, it outputs high-precision frequency signals to the outside. The rubidium atomic clock module mainly includes key components such as the power supply unit, rubidium atomic physical unit, mixing unit, servo unit, and control unit.

[0076] The SOC processor mainly completes the Beidou receiver message processing, rubidium atomic clock training, output signal generation, and timing accuracy analysis functions. The SOC processor module mainly includes key components such as the power supply unit, storage unit, and processor unit.

[0077] The timing signal output module mainly completes the timing signal encoding and timing signal distribution functions. The timing signal output module mainly includes key components such as the signal encoding unit and the signal distribution unit.

[0078] refer to Figure 2 As shown in the figure, the working process of the dual Beidou receiver timing system is as follows:

[0079] Step 1: The Beidou receiver receives Beidou satellite signals through the Beidou antenna, captures and tracks the Beidou satellite, and then outputs the original observation message, time message and second pulse signal.

[0080] Step 2: The processor detects the validity of the receiver's message, detects the satellite's carrier-to-noise ratio and elevation angle, and sets the satellite carrier-to-noise ratio threshold to (usually 35dBc), the satellite elevation angle threshold is (Generally 15°). Satellites with carrier-to-noise ratio and elevation angle less than the threshold are eliminated. At the same time, the time continuity of the Beidou receiver output message is tested.

[0081] Step three, by comparing the phase deviation values ​​between Beidou receiver A, rubidium atomic clock and Beidou receiver B, we can obtain the phase deviation value between rubidium atomic clock and Beidou receiver A, the phase deviation value between rubidium atomic clock and Beidou receiver B, and the phase deviation value between Beidou receiver A and Beidou receiver B, and use the "triangle cross phase deviation comparison analysis method" to analyze the timing accuracy of the dual-channel Beidou receiver.

[0082] Step 4: According to the results of steps 1 to 3, calibrate the core time of the timing system. At the same time, the phase and frequency deviation of the timing system are corrected based on the calculation results of the "triangle cross phase deviation comparison analysis method".

[0083] Step 5: The timing system outputs high-precision timing signals and frequency signals based on the corrected time phase and frequency.

[0084] refer to Figure 3 and Figure 4 As shown, the accuracy analysis method includes the following steps:

[0085] First, the Beidou receiver outputs the message to the SOC processor (System On Chip Processor) for parsing of the time, location, satellite carrier-to-noise ratio, satellite PDOP information, satellite elevation angle, etc.

[0086] Next, the SOC processor screens the visible satellites according to the satellite elevation angle and carrier-to-noise ratio, and removes satellites with a carrier-to-noise ratio lower than 35dBc and a satellite elevation angle lower than 15 degrees. Satellites with better observation quality are used for time and frequency synchronization.

[0087] The next step is to divide the 10MHz output of the rubidium atomic clock with a division ratio of 10000000:1. The 10MHz frequency of the rubidium atomic clock is divided into 1Hz and used as the start trigger signal of the TDC (Time to Digital Convert) time digital converter of Beidou receiver A and Beidou receiver B.

[0088] In the next step, the pulse-per-second signal output by Beidou receiver A is used as the Stop trigger signal for the A-th TDC, and the pulse-per-second signal output by Beidou receiver B is used as the Stop trigger signal for the B-th TDC.

[0089] In the next step, the pulse-per-second signal output by Beidou receiver A is used as the Start trigger signal of the C-th TDC, and the pulse-per-second signal output by Beidou receiver B is used as the Stop trigger signal of the C-th TDC.

[0090] Next, the SOC processor waits for the interrupt trigger signal of the A-th TDC. If the interrupt trigger signal of the A-th TDC is received, the time interval measurement value of the A-th channel is immediately read; at the same time, the SOC processor waits for the interrupt trigger signal of the B-th TDC. If the interrupt trigger signal of the B-th TDC is received, the time interval measurement value of the B-th channel is immediately read; at the same time, the SOC processor waits for the interrupt trigger signal of the C-th TDC. If the interrupt trigger signal of the C-th TDC is received, the time interval measurement value of the C-th channel is immediately read;

[0091] The next step is to determine whether there are any abnormal jump values ​​in the change of the time interval measurement values ​​of channels A, B, and C. If the change value exceeds the threshold, discard this group of measurement values ​​and continue with the next group of measurements. Then, use the triangular cross-phase comparison method to accurately analyze the timing accuracy of Beidou receiver A and Beidou receiver B.

[0092] In order to accurately analyze the timing accuracy of the dual Beidou timing system, the present invention proposes a triangular cross phase deviation comparison and analysis method. The method can effectively eliminate the influence of abnormal phase jump of the receiver on the timing accuracy by comparing the phases of Beidou receiver A, Beidou receiver B and local rubidium atomic clock one by one.

[0093] In the triangular cross phase deviation comparison analysis method, the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal generated by the local rubidium atomic clock is first analyzed, then the phase deviation between the second pulse signal of Beidou receiver B and the second pulse signal generated by the local rubidium atomic clock is analyzed, and finally the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal of Beidou receiver B is analyzed. The phase residual error value of Beidou receiver A and the phase residual error value of Beidou receiver B are calculated through the original observation message.

[0094] According to the above phase deviation value, phase residual error value and the difference between the phase residual error values, determine whether there is an abnormal jump value. If the change value exceeds a preset threshold, discard the group of measurement values ​​and continue with the next group of measurements;

[0095] Record the measured values ​​for a period of time. Usually the recording time can be set to 3600 seconds.

[0096] By analyzing the recorded measurement values, we can analyze the advantages and disadvantages of the timing accuracy of Beidou receiver A and Beidou receiver B. The specific analysis steps are as follows:

[0097] The first step is to calculate whether the phase deviation between Beidou receiver A and the rubidium atomic clock and the phase deviation between Beidou receiver B and the rubidium atomic clock exceed the set threshold. If the phase deviations of both receiver A and receiver B exceed the set threshold, it returns that both receiver A and receiver B are unavailable, otherwise proceed to the next step for judgment;

[0098] The second step is to compare the offset of the phase deviation value between Beidou receiver A and the rubidium atomic clock with the offset of the phase deviation value between Beidou receiver B and the rubidium atomic clock. If the offset of the phase deviation value between receiver A and the rubidium atomic clock is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the offset of the phase deviation value between receiver A and the rubidium atomic clock is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the offset of the phase deviation value between receiver A and the rubidium atomic clock is equal to that of receiver B, proceed to the next step for judgment;

[0099] The third step is to compare the discrete degree of the phase deviation value between Beidou receiver A and the rubidium atomic clock with the discrete degree of the phase deviation value between Beidou receiver B and the rubidium atomic clock. If the discrete degree of the phase deviation value between receiver A and the rubidium atomic clock is greater than that of receiver B, then it is returned that the timing accuracy of receiver B is better than that of receiver A, and the phase adjustment value of receiver B is also returned; if the discrete degree of the phase deviation value between receiver A and the rubidium atomic clock is less than that of receiver B, then it is returned that the timing accuracy of receiver A is better than that of receiver B, and the phase adjustment value of receiver A is also returned; if the discrete degree of the phase deviation value between receiver A and the rubidium atomic clock is equal to that of receiver B, then proceed to the next step for judgment;

[0100] The fourth step is to compare the offsets of the phase deviation values ​​of Beidou receiver A and Beidou receiver B. If the offset of the phase deviation value of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the offset of the phase deviation value of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the offset of the phase deviation value of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0101] The fifth step is to compare the discreteness of the phase deviation values ​​of Beidou receiver A and Beidou receiver B. If the discreteness of the phase deviation value of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the discreteness of the phase deviation value of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the discreteness of the phase deviation value of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0102] The sixth step is to compare the offsets of the phase residual error values ​​of Beidou receiver A and Beidou receiver B. If the offset of the phase residual error value of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the offset of the phase residual error value of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the offset of the phase residual error value of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0103] The seventh step is to compare the discreteness of the phase residual error values ​​of Beidou receiver A and Beidou receiver B. If the discreteness of the phase residual error value of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the discreteness of the phase residual error value of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the discreteness of the phase residual error value of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0104] Step 8. Compare the number of available satellites of Beidou receiver A and Beidou receiver B. If the number of available satellites of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and also returns the phase adjustment value of receiver A; if the number of available satellites of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and also returns the phase adjustment value of receiver B; if the number of available satellites of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0105] The ninth step is to compare the carrier-to-noise ratio of the same satellite of Beidou receiver A and Beidou receiver B. If the carrier-to-noise ratio of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the carrier-to-noise ratio of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the carrier-to-noise ratio of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0106] Step 10: Compare the PDOP values ​​of Beidou receiver A and Beidou receiver B. If the PDOP value of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the PDOP value of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A; if the PDOP value of receiver A is equal to that of receiver B, proceed to the next step for judgment;

[0107] The eleventh step is to compare the priority values ​​of Beidou receiver A and Beidou receiver B. If the priority value of receiver A is greater than that of receiver B, it returns that the timing accuracy of receiver B is better than that of receiver A, and returns the phase adjustment value of receiver B; if the priority value of receiver A is less than that of receiver B, it returns that the timing accuracy of receiver A is better than that of receiver B, and returns the phase adjustment value of receiver A.

[0108] Through the above steps, the offset degree of the phase deviation value, the discrete degree of the phase deviation value, the offset degree of the phase residual error value, the discrete degree of the phase residual error value, the number of available satellites, the carrier-to-noise ratio, and the PDOP value of the Beidou receiver A and Beidou receiver B are analyzed and compared. Then, the timing accuracy results and the phase adjustment value of Beidou receiver A and Beidou receiver B are obtained through analysis.

[0109] The triangular cross phase deviation comparison and analysis method further includes:

[0110] According to the timing accuracy result and the phase adjustment value result, a system phase adjustment value and a system frequency adjustment control word are generated to calibrate the phase and frequency of the timing system.

[0111] The timing signal output module performs the following steps:

[0112] receiving a calibrated and corrected time phase signal and frequency signal provided by a SOC processor;

[0113] These signals are encoded, and the encoded timing signals and frequency signals are distributed to the devices to be time synchronized.

[0114] In summary, the present invention proposes a dual Beidou receiver timing system, which can output high-precision timing signals after internal processing; at the same time, it can eliminate the problem that a single receiver cannot model the changing trend of the second pulse signal. By analyzing the changing trend of the second pulse signal output by the receiver, the slow changing trend of the Beidou receiver is modeled, and the synchronization accuracy of the timing system is improved.

[0115] It can also correctly identify whether the reference source is centrally symmetrically distributed, right-skewed, or left-skewed. Among them, three types of phase deviation distribution characteristics are mainly identified, the first is centrally symmetrical distribution, the second is right-skewed distribution, and the third is left-skewed distribution. Among them, the first type of centrally symmetrical distribution is the reference source with the best quality. The degree of deviation between the right-skewed distribution and the left-skewed distribution represents the quality of the reference source.

[0116] At the same time, the present invention analyzes the timing accuracy of the dual-channel Beidou receiver through the "triangle cross phase deviation comparison analysis method", and corrects the time phase and frequency deviation of the timing system according to the analysis results, so that the timing system can output high-precision time synchronization signals and frequency synchronization signals.

[0117] Embodiment 2

[0118] In this embodiment, taking Beidou receiver A and Beidou receiver B as examples, the working process of the timing accuracy analysis method is described in detail below:

[0119] refer to Figure 3 and Figure 4As shown, the accuracy analysis method includes the following steps:

[0120] First, the Beidou receiver outputs the message to the SOC processor (System On Chip Processor) for parsing of the time, location, satellite carrier-to-noise ratio, satellite PDOP information, satellite elevation angle, etc.

[0121] Next, the SOC processor screens the visible satellites according to the satellite elevation angle and carrier-to-noise ratio, and removes satellites with a carrier-to-noise ratio lower than 35dBc and a satellite elevation angle lower than 15 degrees. Satellites with better observation quality are used for time and frequency synchronization.

[0122] The next step is to divide the 10MHz output of the rubidium atomic clock with a division ratio of 10000000:1. The 10MHz frequency of the rubidium atomic clock is divided into 1Hz and used as the start trigger signal of the TDC (Time to Digital Convert) time digital converter of Beidou receiver A and Beidou receiver B.

[0123] In the next step, the pulse-per-second signal output by Beidou receiver A is used as the Stop trigger signal for the A-th TDC, and the pulse-per-second signal output by Beidou receiver B is used as the Stop trigger signal for the B-th TDC.

[0124] In the next step, the pulse-per-second signal output by Beidou receiver A is used as the Start trigger signal of the C-th TDC, and the pulse-per-second signal output by Beidou receiver B is used as the Stop trigger signal of the C-th TDC.

[0125] Next, the SOC processor waits for the interrupt trigger signal of the A-th TDC. If the interrupt trigger signal of the A-th TDC is received, the time interval measurement value is immediately read. At the same time, the SOC processor waits for the interrupt trigger signal of the B-th TDC. If the interrupt trigger signal of the B-th TDC is received, the time interval measurement value is immediately read. At the same time, the SOC processor waits for the interrupt trigger signal of the C-th TDC. If the interrupt trigger signal of the C-th TDC is received, the time interval measurement value is immediately read. ;

[0126] Next step judgment , , Whether there is an abnormal jump value in the change of the value, if the change value exceeds the threshold, discard this group of measurement values, continue with the next group of measurements, and then use the triangular cross-phase deviation comparison method to accurately analyze the timing accuracy of Beidou receiver A and Beidou receiver B.

[0127] Among them, the A-th time digital converter is used to measure the phase deviation between the second pulse signal output by Beidou receiver A and the 1Hz (second pulse) signal generated by the local rubidium atomic clock.

[0128] The B-channel time-to-digital converter is used to measure the phase deviation between the second pulse signal output by Beidou receiver B and the 1Hz (second pulse) signal generated by the local rubidium atomic clock.

[0129] The C-th time-to-digital converter is used to measure the phase deviation between the second pulse signal output by Beidou receiver A and the second pulse signal output by Beidou receiver B.

[0130] like Figure 5 and Figure 6 As shown, the A-th time digital converter, the B-th time digital converter, and the C-th time digital converter all operate independently and are used to measure the phase deviation values ​​between Beidou receiver A, Beidou receiver B, and the local rubidium atomic clock. The three-way time digital converters output the three-way phase deviation values ​​to the "triangle cross phase deviation comparison analysis method" for analysis and calculation.

[0131] like Figure 7 As shown, the Start trigger signals of the A-th time digital converter and the B-th time digital converter are both from the local rubidium atomic clock, and the Start trigger signal of the C-th time digital converter comes from Beidou receiver A.

[0132] The Stop signal of the A-th time digital converter comes from Beidou receiver A. When the A-th time digital converter receives the Start trigger signal, the internal high-precision timer starts timing. When the A-th time digital converter receives the Stop trigger signal, the internal high-precision timer stops timing. The value recorded by the internal high-precision timer is the phase deviation between the Start trigger signal and the Stop trigger signal of the A-th time digital converter.

[0133] The Stop signal of the B-th time digital converter comes from Beidou receiver B. When the B-th time digital converter receives the Start trigger signal, the internal high-precision timer starts timing. When the B-th time digital converter receives the Stop trigger signal, the internal high-precision timer stops timing. The value recorded by the internal high-precision timer is the phase deviation value between the Start trigger signal and the Stop trigger signal of the B-th time digital converter.

[0134] The Stop signal of the C-th time digital converter comes from Beidou receiver B. When the C-th time digital converter receives the Start trigger signal, the internal high-precision timer starts timing. When the C-th time digital converter receives the Stop trigger signal, the internal high-precision timer stops timing. The value recorded by the internal high-precision timer is the phase deviation value between the Start trigger signal and the Stop trigger signal of the C-th time digital converter.

[0135] In order to accurately analyze the timing accuracy of the dual Beidou timing system, the present invention proposes a triangular cross phase deviation comparison and analysis method. The method can effectively eliminate the influence of abnormal phase jump of the receiver on the timing accuracy by comparing the phases of Beidou receiver A, Beidou receiver B and local rubidium atomic clock one by one.

[0136] In the triangular cross phase deviation comparison analysis method, the phase deviation value between the second pulse signal of the Beidou receiver A and the second pulse signal generated by the local rubidium atomic clock is first analyzed. , and then analyze the phase deviation between the second pulse signal of Beidou receiver B and the second pulse signal generated by the local rubidium atomic clock Finally, the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal of Beidou receiver B is analyzed. The phase residual error value of Beidou receiver A is calculated by the original observation message , the phase residual error value of Beidou receiver B .

[0137] The first step is to calculate the phase deviation between the second pulse signal generated by Beidou receiver A and the local rubidium atomic clock. , and at the same time Store in array middle;

[0138] Next, calculate the phase deviation between the second pulse signal generated by Beidou receiver B and the local rubidium atomic clock , and at the same time Store in array middle;

[0139] Next, calculate the phase deviation between the second pulse signals of Beidou receiver A and Beidou receiver B , and at the same time Store in array middle;

[0140] Next, calculate the phase deviation value of Beidou receiver A:

[0141]

[0142] Where n is the phase deviation value recording time, is the phase deviation between Beidou receiver A and the local rubidium atomic clock at the i-th moment, is the residual phase error between Beidou receiver A and the local rubidium atomic clock at the i-th moment;

[0143] Next, calculate the frequency deviation value of Beidou receiver A:

[0144]

[0145] Where n is the phase deviation value recording time, To record the end time, To record the start time;

[0146] Next, calculate the phase deviation value of Beidou receiver B:

[0147]

[0148] Where n is the phase deviation value recording time, is the phase deviation between Beidou receiver B and the local rubidium atomic clock at the i-th moment, is the residual phase error between Beidou receiver B and the local rubidium atomic clock at the i-th moment;

[0149] Next, calculate the frequency deviation value of Beidou receiver B:

[0150]

[0151] Where n is the phase deviation value recording time, To record the end time, To record the start time;

[0152] The next step is to analyze and calculate the phase deviation between Beidou receiver A and the rubidium atomic clock.

[0153]

[0154] The next step is to analyze and calculate the phase deviation between Beidou receiver B and the rubidium atomic clock.

[0155]

[0156] because Represents the phase deviation between Beidou receiver A and the rubidium atomic clock. Represents the offset of the phase deviation between Beidou receiver B and the rubidium atomic clock. The two values ​​should be approximately equal. If this value exceeds 3, it means that the Beidou receiver has poor satellite reception or is subject to interference.

[0157] The next step is to analyze and calculate the phase deviation between Beidou receiver A and Beidou receiver B.

[0158]

[0159] Where n is the phase deviation value recording time, is the phase deviation between BeiDou receiver A and BeiDou receiver B at the i-th moment;

[0160] because Represents the phase deviation between Beidou receiver A and Beidou receiver B. The value of Beidou receivers of the same model should be close to 0. If this value exceeds 1, one Beidou receiver has poor satellite reception or is interfered with. If this happens, further analysis is needed to determine which Beidou receiver is faulty or interfered with. and .if and The values ​​are close, indicating that this group and Values ​​are available if If the value is greater than the set threshold, the Beidou receiver is faulty or interfered. and Beidou receivers with large absolute values ​​of phase offset have a higher probability of failure.

[0161] The next step is to analyze and calculate the discrete degree of the phase deviation value between Beidou receiver A and the rubidium atomic clock.

[0162]

[0163] The next step is to analyze and calculate the discrete degree of the phase deviation value between Beidou receiver B and the rubidium atomic clock.

[0164]

[0165] because Represents the discrete degree of the phase deviation value between Beidou receiver A and the rubidium atomic clock. Represents the discrete degree of the phase deviation value between Beidou receiver B and the rubidium atomic clock. The larger the two values, the higher the timing accuracy of the Beidou receiver.

[0166] The next step is to analyze and calculate the discrete degree of the phase deviation value between Beidou receiver A and Beidou receiver B.

[0167]

[0168] because Represents the discrete degree of phase deviation between Beidou receiver A and Beidou receiver B. The value of Beidou receivers of the same model should be greater than 3. If the value is less than 3, one Beidou receiver has poor satellite reception or is interfered with. If this happens, further analysis is needed to determine which Beidou receiver is faulty or interfered with. and .if and The values ​​are close, indicating that this group and Values ​​are available if If the value is greater than the set threshold, the Beidou receiver is faulty or interfered. and Beidou receivers with large absolute values ​​of phase offset have a higher probability of failure.

[0169] Since the long-term stability of the rubidium atomic clock is good, it is possible to analyze which Beidou receiver has poor timing accuracy, thereby recording the status of the faulty Beidou receiver and reporting it to the control system.

[0170] if The value approaches 0 and Greater than 3, If the value is within the set threshold, it indicates that Beidou receiver A and Beidou receiver B are working normally. Then proceed to the next step to calculate the phase adjustment value and perform phase adjustment.

[0171] The next step is to analyze and calculate the timing accuracy of Beidou receiver A.

[0172]

[0173] The next step is to analyze and calculate the timing accuracy of Beidou receiver B.

[0174]

[0175] Next, calculate the phase adjustment value of Beidou receiver A:

[0176]

[0177] Next, calculate the phase adjustment value of Beidou receiver B:

[0178]

[0179] Next, calculate the phase adjustment value of the device :

[0180]

[0181] Next, calculate the frequency adjustment control word of the device :

[0182]

[0183] According to the timing accuracy result and the phase adjustment value result, a system phase adjustment value and a system frequency adjustment control word are generated to calibrate the phase and frequency of the timing system.

[0184] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0185] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, the storage medium including a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically-erasable programmable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0186] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

Claims

1. A timing system based on dual Beidou receivers, characterized in that: The system includes a pair of Beidou antennas, a pair of Beidou receivers, a SOC processor, a local rubidium atomic clock and a timing signal output module, wherein: A pair of Beidou antennas, used to receive navigation signals from Beidou satellites and transmit them to corresponding Beidou receivers, including Beidou antenna A and Beidou antenna B; A pair of Beidou receivers, respectively connected to corresponding Beidou antennas, are used to capture and track Beidou satellite signals and output original observation message, time message and second pulse signal, including Beidou receiver A and Beidou receiver B; A local rubidium atomic clock is used to generate a clock signal and output a frequency signal; The SOC processor is used to receive and process the original observation message and time message, and detect the validity and time continuity of the time message. At the same time, it calculates the time phase correction value and the frequency deviation correction value through the triangular cross phase deviation comparison analysis method, and corrects the core time of the timing system to generate the corrected time signal and frequency signal; The timing signal output module is connected to the SOC processor and is used to receive and encode the calibrated and corrected time signal and frequency signal, and finally distribute them to the device to be time synchronized.

2. A timing system based on dual Beidou receivers according to claim 1, characterized in that: The SOC processor specifically performs the following steps: The validity of the original observation message output by the Beidou receiver is tested, including the carrier-to-noise ratio, elevation angle, phase residual error value, satellite PDOP information value and number of available satellites of the Beidou satellite, and the satellite carrier-to-noise ratio threshold is set to 35dBc, the satellite elevation angle threshold is set to 15°, and the satellites with carrier-to-noise ratio and elevation angle below the threshold are eliminated; Check the time continuity of the Beidou receiver's output time message; Use the second pulse signal output by the Beidou receiver to compare the phase deviation with the second pulse signal generated by the local rubidium atomic clock, and obtain the phase deviation value between the local rubidium atomic clock, Beidou receiver A and Beidou receiver B; According to the phase residual error value and the phase deviation value, the timing accuracy of the dual-channel Beidou receiver is analyzed by using a triangular cross phase deviation comparison analysis method, and a time phase correction value and a frequency deviation correction value are calculated; According to the time phase correction value and the frequency offset correction value, the core time of the timing system is calibrated, and the time phase and frequency offset of the timing system are corrected.

3. A timing system based on dual Beidou receivers according to claim 2, characterized in that: The SOC processor also includes: Time digital converter, used to measure the time interval between the 1Hz signal generated by the local rubidium atomic clock and the second pulse signal output by Beidou receiver A and Beidou receiver B; Specifically, the 10 MHz frequency output by the local rubidium atomic clock is divided into 1 Hz with a division ratio of 10000000:1, which is used as the Start trigger signal of the time digital converter. The pulse-per-second signal output by Beidou receiver A is used as the Stop trigger signal of the A-th time-to-digital converter, and the pulse-per-second signal output by Beidou receiver B is used as the Stop trigger signal of the B-th time-to-digital converter; The second pulse signal output by Beidou receiver A is used as the Start trigger signal of the C-th time digital converter, and the second pulse signal output by Beidou receiver B is used as the Stop trigger signal of the C-th time digital converter.

4. A timing system based on dual Beidou receivers according to claim 3, characterized in that: The triangular cross phase deviation comparison and analysis method specifically includes: Calculate the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal generated by the local rubidium atomic clock and calculate the phase residual error value of Beidou receiver A; Calculate the phase deviation between the second pulse signal of Beidou receiver B and the second pulse signal generated by the local rubidium atomic clock and calculate the phase residual error value of Beidou receiver B; Calculate the phase deviation between the second pulse signal of Beidou receiver A and the second pulse signal of Beidou receiver B; According to the above phase deviation value, phase residual error value and the difference between the phase residual error values, determine whether there is an abnormal jump value. If the change value exceeds a preset threshold, discard the group of measurement values ​​and continue with the next group of measurements; Record the measured values ​​within the set time, and by processing the recorded measured values, you can get the timing accuracy of Beidou receiver A and Beidou receiver B. The specific processing steps are as follows: The first step is to calculate whether the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock and the offset of the phase deviation value between Beidou receiver B and the local rubidium atomic clock exceed the set threshold; if the offset of the phase deviation value of Beidou receiver A and Beidou receiver B exceeds the set threshold, it returns that Beidou receiver A and Beidou receiver B are both unavailable, otherwise proceed to the next step for judgment; The second step is to compare the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock and the offset of the phase deviation value between Beidou receiver B and the local rubidium atomic clock; if the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is greater than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and the phase adjustment value of Beidou receiver B is returned; if the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is less than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and the phase adjustment value of Beidou receiver A is returned; if the offset of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is equal to that of Beidou receiver B, proceed to the next step for judgment; The third step is to compare the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock and the discrete degree of the phase deviation value between Beidou receiver B and the local rubidium atomic clock; if the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is greater than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and the phase adjustment value of Beidou receiver B is returned; if the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is less than that of Beidou receiver B, then it is returned that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and the phase adjustment value of Beidou receiver A is returned; if the discrete degree of the phase deviation value between Beidou receiver A and the local rubidium atomic clock is equal to that of Beidou receiver B, proceed to the next step for judgment; The fourth step is to compare the offset of the phase deviation value of Beidou receiver A and Beidou receiver B; if the offset of the phase deviation value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the offset of the phase deviation value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the offset of the phase deviation value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment; The fifth step is to compare the discrete degrees of the phase deviation values ​​of Beidou receiver A and Beidou receiver B; if the discrete degree of the phase deviation value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the discrete degree of the phase deviation value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the discrete degree of the phase deviation value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment; The sixth step is to compare the offset of the phase residual error value of Beidou receiver A and Beidou receiver B; if the offset of the phase residual error value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the offset of the phase residual error value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the offset of the phase residual error value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment; The seventh step is to compare the discrete degrees of the phase residual error values ​​of Beidou receiver A and Beidou receiver B; if the discrete degree of the phase residual error value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the discrete degree of the phase residual error value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the discrete degree of the phase residual error value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment; Step 8. Compare the number of available satellites of Beidou receiver A and Beidou receiver B. If the number of available satellites of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A. If the number of available satellites of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B. If the number of available satellites of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment. The ninth step is to compare the carrier-to-noise ratio of the same satellite of Beidou receiver A and Beidou receiver B; if the carrier-to-noise ratio of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A; if the carrier-to-noise ratio of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the carrier-to-noise ratio of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment; Step 10. Compare the PDOP values ​​of Beidou receiver A and Beidou receiver B. If the PDOP value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B. If the PDOP value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A. If the PDOP value of Beidou receiver A is equal to that of Beidou receiver B, proceed to the next step for judgment. The eleventh step is to compare the priority values ​​of Beidou receiver A and Beidou receiver B; if the priority value of Beidou receiver A is greater than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver B is better than that of Beidou receiver A, and returns the phase adjustment value of Beidou receiver B; if the priority value of Beidou receiver A is less than that of Beidou receiver B, it returns that the timing accuracy of Beidou receiver A is better than that of Beidou receiver B, and returns the phase adjustment value of Beidou receiver A.

5. A timing system based on dual Beidou receivers according to claim 4, characterized in that: The triangular cross phase deviation comparison and analysis method further includes: According to the timing accuracy result and the phase adjustment value, a system phase adjustment value and a system frequency adjustment control word are generated to calibrate the phase and frequency of the timing system.

6. A timing system based on dual Beidou receivers according to claim 5, characterized in that: The timing signal output module performs the following steps: receiving a calibrated and corrected time phase signal and frequency signal provided by a SOC processor; These signals are encoded, and the encoded timing signals and frequency signals are distributed to the devices to be time synchronized.

7. A timing accuracy analysis method based on dual Beidou receivers, applied to a timing system based on dual Beidou receivers as described in any one of claims 1 to 6, characterized in that: The method comprises the following steps: The Beidou receiver receives Beidou satellite signals through the Beidou antenna, captures and tracks the Beidou satellite, and then outputs the original observation message, time message and second pulse signal; The SOC processor receives and processes the original observation message and time message, detects the satellite's carrier-to-noise ratio, elevation angle, phase residual error value, satellite PDOP information value and the number of available satellites, sets the satellite carrier-to-noise ratio threshold to 35dBc, and the satellite elevation angle threshold to 15°, removes satellites with carrier-to-noise ratio and elevation angle below the threshold, and detects the time continuity of the time message output by the Beidou receiver; Use the second pulse signal output by the Beidou receiver to compare the phase deviation with the second pulse signal generated by the local rubidium atomic clock, and obtain the phase deviation value between the local rubidium atomic clock, Beidou receiver A and Beidou receiver B; The triangular cross phase deviation comparison analysis method is used to analyze the timing accuracy of the dual-channel Beidou receiver, and the phase deviation correction value and frequency deviation correction value are generated according to the timing accuracy value, phase deviation value, and phase residual error value; The core time of the timing system is calibrated according to the time message, and the time phase and frequency deviation of the timing system are corrected by using the phase deviation correction value and frequency deviation correction value calculated by the triangular cross phase deviation comparison analysis method; The timing system outputs timing signals and frequency signals according to the corrected time phase and frequency.

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