Satellite positioning test method and system special for railway based on parallel multiple indexes

Abstract

The invention discloses a parallel multi-index-based satellite positioning test method and system special for a railway. The method comprises the following steps: uploading a primary GNSS signal, a train real track and a train IMU position to a positioning tester; establishing a multi-source feature screening algorithm based on the first-level GNSS signal, calculating a screening score, and screening according to the screening score to obtain a second-level GNSS signal; when the train runs, calculating the maximum deviation between the position of the second-level GNSS signal and the real track, the accumulated deviation and the corrected accumulated deviation to realize a dynamic positioning test; when the train stops, the static recognition rate of the position of the second-level GNSS signal is calculated to achieve static positioning testing, and correction deviation is updated; and outputting a positioning test result. According to the method, the interference of redundant GNSS signals is reduced by adopting a multi-source feature screening algorithm, and the accuracy of a positioning test is improved while the real-time performance is ensured in cooperation with a mode of combining dynamic and static tests.

Description

Technical Field

[0001] The present invention relates to the technical field of positioning test, and in particular to a railway-specific satellite positioning test method and system based on parallel multi-index. Background Art

[0002] As an economic artery, railways have played an important role in the prosperity and development of society. With its speed and convenience, railway transportation has become an indispensable means of transportation for production and life in today's society. Due to its large carrying capacity and convenient passage, railway transportation has played an irreplaceable role in commodity transportation and personnel exchanges. During the passage of railway trains, it is necessary to grasp the train's running track in real time to ensure the safety and efficiency of railway train operation. Therefore, railway satellite positioning technology has gradually become the focus of scientific researchers and front-line workers.

[0003] GNSS and Beidou signals are currently the most widely used satellite positioning technologies and are widely used in my country. How to accurately test the positioning of these satellite signals and give full play to their role in positioning has attracted the attention of technicians. Although traditional satellite positioning test methods can achieve basic positioning test functions, they not only have long test cycles and few test indicators, but also mostly only test dynamic scenes. In the actual operation of trains, there are not only dynamic scenes but also static scenes, and different scenes have different test requirements; in addition, during the test process, redundant information is easily generated due to occlusion and multi-path effects. These redundant information will not only interfere with the test, but also cause computing power loss. Therefore, it is necessary to propose a new railway-specific satellite positioning test method to solve the above problems. Summary of the invention

[0004] The present invention provides a railway-specific satellite positioning test method and system based on parallel multi-index, so as to solve the technical problem that invalid GNSS signals exist in the positioning test process and realize multi-index parallel testing of static scenes and dynamic scenes.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] On the one hand, the present invention provides a railway-specific satellite positioning test method based on parallel multi-index, comprising the following steps:

[0007] S1. Initialize the positions of the two GNSS receivers of the train, initialize the correction deviation, obtain the primary GNSS signal, the actual track of the train and the IMU position of the train and upload them to the positioning tester;

[0008] S2. Establish a multi-source feature screening algorithm based on the primary GNSS signal, calculate the screening score, and obtain the secondary GNSS signal by screening the screening score;

[0009] S3. When the train is running normally, a dynamic hierarchical test algorithm is established to perform a dynamic positioning test. First, the maximum deviation between the position of the secondary GNSS signal and the true trajectory is calculated. If the maximum deviation is less than the maximum deviation threshold, the cumulative deviation is further calculated. If the cumulative deviation is less than the cumulative deviation threshold, the cumulative deviation between the corrected position of the secondary GNSS signal and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails.

[0010] S4. When the train stops at a station, a static deviation test algorithm is established to perform a static positioning test, and the static recognition rate of the position of the secondary GNSS signal is calculated. If the static recognition rate is less than the static recognition rate threshold, the static positioning test fails. Otherwise, the static positioning test succeeds and the correction deviation is updated.

[0011] S5. When the train arrives at the destination and completes all dynamic positioning tests and static positioning tests, the positioning test results are output.

[0012] Furthermore, the step S1 comprises:

[0013] Two GNSS receivers are located in the first carriage of the train, called R1, and the last carriage of the train, called R2. The first-level GNSS signal is obtained through R1 and R2. The first-level GNSS signal contains position information and power information. The calculation process of the position of the first-level GNSS signal is as follows:

[0014] R1 and R2 receive GNSS signals and obtain corresponding positions respectively and

[0015]

[0016] Where m represents the number of GNSS signals received by the GNSS receiver during the test period. represents the position of R1 when it receives the i-th GNSS signal, represents the position of R2 when it receives the i-th GNSS signal;

[0017] Depend on and Calculate the position of the primary GNSS signal

[0018]

[0019] in, represents the train position corresponding to the i-th GNSS signal;

[0020] Initialize the correction bias β;

[0021] Determine the train's route and obtain the train's actual track through an electronic map;

[0022] The train IMU is located in the middle of the train, that is, the middle position of the two GNSS receivers R1 and R2. The train IMU position P is calculated by the train IMU signal. IMU :

[0023]

[0024] Where n represents the number of train IMU signals during the test period, Indicates the train IMU position corresponding to the i-th train IMU signal;

[0025] Upload the primary GNSS signal, the actual train track and the train IMU position to the positioning tester.

[0026] It should be noted that the position of the primary GNSS signal is obtained by combining two GNSS receivers, which can avoid systematic errors caused by failure of a single receiver; the correction deviation β is obtained by empirical value, and the average value of historical tests is taken in the present invention; since the running track of the train is fixed, the real track can be obtained from the electronic map.

[0027] Furthermore, the step S2 comprises:

[0028] S21, initializing the power threshold τ and the depth threshold h;

[0029] S22. Calculate the depth of the position of the primary GNSS signal The i-th level GNSS signal

[0030]

[0031] S23. Calculate the power fraction F g , if the power g of the i-th level GNSS signal i is greater than or equal to τ, then the i-th power fraction If the power of the i-th primary GNSS signal g i is less than τ, then the i-th power fraction

[0032] S24. Calculate the first-level GNSS signal score If the position of the i-th primary GNSS signal Depth If it is greater than or equal to h or less than or equal to 0.5*h, then the i-th level 1 GNSS signal score Otherwise, the i-th level GNSS signal score

[0033] S25. Calculate screening score The i-th screening score The specific expression is as follows:

[0034]

[0035] if If it is 2, it means that the primary GNSS signal is valid and marked as a secondary GNSS signal, otherwise the primary GNSS signal is invalid.

[0036] It should be noted that the satellite positioning test in the present invention is completed on a positioning tester, so all required location information needs to be uploaded to the positioning tester. By establishing a multi-source feature screening algorithm, the position of the first-level GNSS signal and the power of the first-level GNSS signal can be used to achieve joint screening, eliminate redundant signals, reduce interference from GNSS signals and erroneous signals affected by occlusion or multi-path effects, reduce the computing power required for subsequent tests, and thus improve test efficiency.

[0037] Furthermore, the step S3 comprises:

[0038] When the train is running normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning test:

[0039] S31, Level 1 dynamic positioning test:

[0040] Determine the dynamic positioning test interval and calculate the position of the secondary GNSS signal within the dynamic positioning test interval and the actual train track The deviation between

[0041]

[0042] Among them, m D Indicates the number of secondary GNSS signals received within the dynamic positioning test interval. represents the position of the i-th secondary GNSS signal in the dynamic positioning test interval, represents the actual position of the train at the time of the i-th GNSS signal in the dynamic positioning test section, express The depth of express Depth

[0043] Calculate Deviation The maximum value of

[0044] Initialize the maximum deviation threshold ρ, if it exists This indicates that the dynamic positioning test has failed, otherwise the secondary dynamic positioning test is performed;

[0045] S32, Level 2 dynamic positioning test:

[0046] Calculate the cumulative deviation ε within the dynamic positioning test interval D :

[0047]

[0048] Initialize the cumulative deviation threshold ω;

[0049] If ε D ≥ω, it indicates that the dynamic positioning test has failed, otherwise the third-level dynamic positioning test is performed;

[0050] S33, Level 3 dynamic positioning test:

[0051]

[0052] It should be noted that since the train is in a dynamic operation state for a long time, the present invention specially designs a dynamic grading test algorithm. Compared with a single test, the grading method can timely detect the test failure, and the dynamic positioning test of multiple indicators can further improve the test accuracy.

[0053] Furthermore, the step S4 comprises:

[0054] When the train stops at a station, a static deviation test algorithm is established to perform a static positioning test:

[0055] S41. The sensors in the station obtain the accurate position of the train center at each time, and obtain the train center position when it stops. Get the stop time period T s Position of the secondary GNSS signal and train IMU position

[0056] S42, calculate the static recognition rate:

[0057] S421. Calculate the position of the secondary GNSS signal and train center location The deviation between

[0058]

[0059] in, Indicates the stop time period T s The number of secondary GNSS signals within represents the position of the i-th secondary GNSS signal during the stop time period, Represents the position of the i-th secondary GNSS signal and train center location The x-axis coordinate of the deviation between Represents the position of the i-th secondary GNSS signal and train center location The y-axis coordinate of the deviation between

[0060] Calculate Deviation The average

[0061]

[0062] Calculate Deviation Standard Deviation and

[0063] S422, calculate train IMU position and train center location The deviation between

[0064]

[0065]

[0066] in, Indicates the stop time period T s The number of in-train IMU signals, represents the train IMU position corresponding to the IMU signal of the i-th train during the stop time period, Indicates the IMU position of the i-th train and train center location The x-axis coordinate of the deviation between Indicates the IMU position of the i-th train and train center location The y-axis coordinate of the deviation between

[0067] Calculate Deviation The average

[0068]

[0069]

[0070] otherwise

[0071] if and Then the flag otherwise

[0072] S424: Count and obtain the position of the secondary GNSS signal The number of flag bits that are 1 Statistics get the train IMU position The number of n bits whose flag is 1 IMU-true ;

[0073] S425. Calculate the position of the secondary GNSS signal Static recognition rate

[0074]

[0075] Calculate train IMU position The static recognition rate γ IMU-true :

[0076]

[0077] S426, initialize the static recognition rate threshold α2, if It means that the secondary GNSS signal static positioning test is successful. It means that the secondary GNSS signal static positioning test fails. If γ IMU-true ≥α2, it means the train IMU signal is intact. If γ IMU-true <α2, it means that there is a fault in the train IMU signal, and an alarm is prompted;

[0078] S43. Update the correction deviation.

[0079] Furthermore, the process of updating the correction deviation in step S4 includes:

[0080] Get the number of positions of the secondary GNSS signal in the last dynamic positioning test cycle Where D i represents the i-th dynamic test cycle;

[0081] Calculate the cumulative deviation during the last dynamic positioning test cycle

[0082]

[0083] in, express The depth of express Depth

[0084] Calculate the cumulative average position deviation during the last dynamic positioning test cycle

[0085]

[0086] It should be noted that the present invention makes full use of the station information when the train stops at a station during the static positioning test, which can not only test the accuracy of GNSS information, but also test the faultiness of the train IMU signal, thereby providing data support for the smooth operation of subsequent trains.

[0087] In addition, when performing dynamic positioning tests and static positioning tests, a certain dynamic positioning test or static positioning test will not distinguish the number of dynamic positioning tests or static positioning tests, but the positioning tester will automatically record and automatically find the corresponding dynamic positioning test or static positioning test data when needed.

[0088] On the other hand, the present invention also provides a railway-specific satellite positioning test system based on parallel multi-index, comprising the following modules:

[0089] Data acquisition module: Initialize the positions of the two GNSS receivers of the train, initialize the correction deviation, obtain the primary GNSS signal, the actual track of the train and the position of the train IMU and upload them to the positioning tester; establish a multi-source feature screening algorithm based on the primary GNSS signal, calculate the screening score, and obtain the secondary GNSS signal based on the screening score;

[0090] Dynamic positioning test module: When the train is running normally, a dynamic positioning test is performed based on a dynamic hierarchical test algorithm. First, the maximum deviation between the position of the secondary GNSS signal and the true trajectory is calculated. If the maximum deviation is less than the maximum deviation threshold, the cumulative deviation is further calculated. If the cumulative deviation is less than the cumulative deviation threshold, the cumulative deviation between the corrected position of the secondary GNSS signal and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails.

[0091] Static positioning test module: When the train stops at a station, a static positioning test is performed based on the static deviation test algorithm to calculate the static recognition rate of the position of the secondary GNSS signal. If the static recognition rate is less than the static recognition rate threshold, the static positioning test fails. Otherwise, the static positioning test succeeds and the correction deviation is updated.

[0092] Positioning test output module: When the train reaches the destination and completes all dynamic positioning tests and static positioning tests, the positioning test results are output.

[0093] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0094] 1. The present invention adopts a combination of static positioning test and dynamic positioning test to realize the railway-specific satellite positioning test function based on parallel multi-indicators, thereby achieving the purpose of positioning test from both static and dynamic dimensions. Two GNSS receivers are used to receive GNSS signals to avoid systematic errors caused by failure of a single receiver, and a multi-source feature screening algorithm is established to screen out redundant GNSS signals, which is especially effective in occlusion and multi-path environments. Compared with the traditional direct calculation scheme, the present invention can improve the calculation efficiency by 10% to 20%, while reducing the computing power loss of the positioning tester, further reducing the hardware cost, and having obvious economic benefits.

[0095] 2. The present invention selects to perform a static positioning test when the train stops at a station, establishes a static deviation test algorithm based on the center position of the train during the stop period, the position of the secondary GNSS signal and the IMU position of the train, calculates the static recognition rate, and judges whether the static positioning test of the train at this station is successful through the static recognition rate. At the same time, the existing resources of the station are used to obtain the accurate center position of the train when it stops, and further updates the correction deviation to provide data support for subsequent dynamic positioning tests. Compared with the existing algorithms, the present invention can achieve the purpose of completing multiple tests in one train operation, save costs and realize testing of real scenes. Compared with simulation scenes, the test accuracy is higher.

[0096] 3. The present invention adopts a dynamic hierarchical test algorithm when performing dynamic positioning test, calculates the dynamic maximum deviation to complete the first-level test, calculates the cumulative deviation to complete the second-level test, and calculates the corrected cumulative deviation to complete the third-level test, thereby realizing fast and accurate dynamic positioning test; in addition, static positioning test and dynamic positioning test are performed alternately in parallel, and multiple indicators such as static recognition rate, dynamic maximum deviation and cumulative deviation are adopted. Compared with the existing algorithms, the test indicators adopted by the present invention are richer and the test scenarios are more targeted. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0098] Figure 1 A flowchart of a railway-specific satellite positioning test method based on parallel multi-indicators provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0099] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0100] Example 1

[0101] This embodiment will provide a more detailed description of a railway-specific satellite positioning test method based on parallel multi-indexes provided by the present invention in conjunction with the corresponding drawings. Figure 1 As shown, the method mainly includes the following five steps:

[0102] S1. Initialize the positions of the two GNSS receivers of the train, initialize the correction deviation, obtain the primary GNSS signal, the actual track of the train and the IMU position of the train and upload them to the positioning tester;

[0103] S2. Establish a multi-source feature screening algorithm based on the primary GNSS signal, calculate the screening score, and obtain the secondary GNSS signal by screening the screening score;

[0104] S3. When the train is running normally, a dynamic hierarchical test algorithm is established to perform a dynamic positioning test. First, the maximum deviation between the position of the secondary GNSS signal and the true trajectory is calculated. If the maximum deviation is less than the maximum deviation threshold, the cumulative deviation is further calculated. If the cumulative deviation is less than the cumulative deviation threshold, the cumulative deviation between the corrected position of the secondary GNSS signal and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails.

[0105] S4. When the train stops at a station, a static deviation test algorithm is established to perform a static positioning test, and the static recognition rate of the position of the secondary GNSS signal is calculated. If the static recognition rate is less than the static recognition rate threshold, the static positioning test fails. Otherwise, the static positioning test succeeds and the correction deviation is updated.

[0106] S5. When the train arrives at the destination and completes all dynamic positioning tests and static positioning tests, the positioning test results are output.

[0107] Specifically, the step S1 includes:

[0108] Two GNSS receivers are located in the first carriage of the train, called R1, and the last carriage of the train, called R2. The first-level GNSS signal is obtained through R1 and R2. The first-level GNSS signal contains position information and power information. The calculation process of the position of the first-level GNSS signal is as follows:

[0109] R1 and R2 receive GNSS signals and obtain corresponding positions respectively and

[0110]

[0111] Where m represents the number of GNSS signals received by the GNSS receiver during the test period. represents the position of R1 when it receives the i-th GNSS signal, represents the position of R2 when it receives the i-th GNSS signal;

[0112] Depend on and Calculate the position of the primary GNSS signal

[0113]

[0114] in, represents the train position corresponding to the i-th GNSS signal;

[0115] Initialize the correction bias β;

[0116] Determine the train's route and obtain the train's actual track through an electronic map;

[0117] The train IMU is located in the middle of the train, that is, the middle position of the two GNSS receivers R1 and R2. The train IMU position P is calculated by the train IMU signal. IMU :

[0118]

[0119] Where n represents the number of train IMU signals during the test period, Indicates the train IMU position corresponding to the i-th train IMU signal;

[0120] Upload the primary GNSS signal, the actual train track and the train IMU position to the positioning tester.

[0121] In the present invention, the position of the train IMU signal, the first-level GNSS signal and the position in the actual trajectory of the train all describe the same position information; because in the actual test process, the signal frequency of the IMU is often higher than that of other sensor signals, the IMU signal will be locally fitted during calculation. If the IMU collects 10 signals per second and the GNSS signal is 1 signal per second, in order to align the position of the train IMU and the position of the first-level GNSS signal in quantity, the train IMU position will be calculated for each signal collected by the IMU and the average will be taken. Therefore, each signal in the present invention will correspond to a position, that is, the number of signals and the number of positions are consistent.

[0122] The step S2 comprises:

[0123] S21, initializing the power threshold τ and the depth threshold h;

[0124] S22. Calculate the depth of the position of the primary GNSS signal The i-th level GNSS signal

[0125]

[0126] S23. Calculate the power fraction F g , if the power g of the i-th level GNSS signal i is greater than or equal to τ, then the i-th power fraction If the power of the i-th primary GNSS signal g i is less than τ, then the i-th power fraction

[0127] S24. Calculate the first-level GNSS signal score If the position of the i-th primary GNSS signal Depth If it is greater than or equal to h or less than or equal to 0.5*h, then the i-th level 1 GNSS signal score Otherwise, the i-th level GNSS signal score

[0128] S25. Calculate screening score The i-th screening score The specific expression is as follows:

[0129]

[0130] if If it is 2, it means that the primary GNSS signal is valid and marked as a secondary GNSS signal, otherwise the primary GNSS signal is invalid.

[0131] The step S3 comprises:

[0132] When the train is running normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning test:

[0133] S31, Level 1 dynamic positioning test:

[0134] Determine the dynamic positioning test interval and calculate the position of the secondary GNSS signal within the dynamic positioning test interval and the actual train track The deviation between

[0135]

[0136] Among them, m D Indicates the number of secondary GNSS signals received within the dynamic positioning test interval. represents the position of the i-th secondary GNSS signal in the dynamic positioning test interval, represents the actual position of the train at the time of the i-th GNSS signal in the dynamic positioning test section, express The depth of express Depth

[0137] Calculate Deviation The maximum value of

[0138] Initialize the maximum deviation threshold ρ, if it exists This indicates that the dynamic positioning test has failed, otherwise the secondary dynamic positioning test is performed;

[0139] S32, Level 2 dynamic positioning test:

[0140] Calculate the cumulative deviation ε within the dynamic positioning test interval D :

[0141]

[0142] Initialize the cumulative deviation threshold ω;

[0143] If ε D ≥ω, it indicates that the dynamic positioning test has failed, otherwise the third-level dynamic positioning test is performed;

[0144] S33, Level 3 dynamic positioning test:

[0145]

[0146] It should be further explained that, since the value of β can be positive or negative, if the second level test is performed, the positive or negative value of β can also be used to directly determine whether to perform the third level test. If a third level dynamic positioning test is required during the second test, and β is greater than or equal to zero at this time, it can be directly determined that the dynamic positioning test has failed. If β is less than zero, the calculation is performed normally.

[0147] The step S4 comprises:

[0148] When the train stops at a station, a static deviation test algorithm is established to perform a static positioning test:

[0149] S41. The sensors in the station obtain the accurate position of the train center at each time, and obtain the train center position when it stops. Get the stop time period T s Position of the secondary GNSS signal and train IMU position Where s represents the state of the train when it stops at the station;

[0150] S42, calculate the static recognition rate:

[0151] S421. Calculate the position of the secondary GNSS signal and train center location The deviation between

[0152]

[0153] in, Indicates the stop time period T s The number of secondary GNSS signals within represents the position of the i-th secondary GNSS signal during the stop time period, Represents the position of the i-th secondary GNSS signal and train center location The x-axis coordinate of the deviation between express The x-axis coordinate, express The x-axis coordinate, Represents the position of the i-th secondary GNSS signal and train center location The y-axis coordinate of the deviation between express The y-axis coordinate, express The y-axis coordinate of

[0154] Calculate Deviation The average

[0155]

[0156] Calculate Deviation Standard Deviation and

[0157] S422, calculate train IMU position and train center location The deviation between

[0158]

[0159] in, Indicates the stop time period T s The number of in-train IMU signals, represents the train IMU position corresponding to the IMU signal of the i-th train during the stop time period, Indicates the IMU position of the i-th train and train center location The x-axis coordinate of the deviation between Indicates the IMU position of the i-th train and train center location The y-axis coordinate of the deviation between

[0160] Calculate Deviation The average

[0161]

[0162]

[0163] otherwise

[0164] if and Then the flag otherwise

[0165] S424: Count and obtain the position of the secondary GNSS signal The number of flag bits that are 1 Statistics get the train IMU position The number of n bits whose flag is 1 IMU-true ;

[0166] S425, calculate the position of the secondary GNSS signal Static recognition rate

[0167]

[0168] Calculate train IMU position The static recognition rate γ IMU-true :

[0169]

[0170] S426, initialize the static recognition rate threshold α2, if It means that the secondary GNSS signal static positioning test is successful. It means that the secondary GNSS signal static positioning test fails. If γ IMU-true ≥α2, it means the train IMU signal is intact. If γ IMU-true <α2, it means that there is a fault in the train IMU signal, and an alarm is prompted;

[0171] S43, update correction deviation:

[0172] Get the number of positions of the secondary GNSS signal in the last dynamic positioning test cycle Where D i represents the i-th dynamic test cycle;

[0173] Calculate the cumulative deviation during the last dynamic positioning test cycle

[0174]

[0175] in, express The depth of express Depth

[0176] Calculate the cumulative average position deviation during the last dynamic positioning test cycle

[0177]

[0178] By designing a dynamic grading test algorithm in the present invention, inaccurate dynamic positioning tests can be discovered in a timely manner. If the first-level test fails, there is no need to perform subsequent tests, thereby avoiding the disadvantage of having to go through all test processes to analyze the test results, reducing the computing power requirements of the test method, and thereby reducing the hardware cost of the positioning tester.

[0179] The present invention adopts a parallel multi-index testing method that combines multiple dynamic positioning tests with static positioning tests to realize positioning testing of railway-specific satellite signals. The test scenario is more in line with the actual operation scenario of the train, the test efficiency is higher, and the test results are more accurate.

[0180] Example 2

[0181] This embodiment provides a railway-specific satellite positioning test system based on parallel multi-index, which mainly includes the following four modules:

[0182] Data acquisition module: Initialize the positions of the two GNSS receivers of the train, initialize the correction deviation, obtain the primary GNSS signal, the actual track of the train and the position of the train IMU and upload them to the positioning tester; establish a multi-source feature screening algorithm based on the primary GNSS signal, calculate the screening score, and obtain the secondary GNSS signal based on the screening score;

[0183] Dynamic positioning test module: When the train is running normally, a dynamic positioning test is performed based on a dynamic hierarchical test algorithm. First, the maximum deviation between the position of the secondary GNSS signal and the true trajectory is calculated. If the maximum deviation is less than the maximum deviation threshold, the cumulative deviation is further calculated. If the cumulative deviation is less than the cumulative deviation threshold, the cumulative deviation between the corrected position of the secondary GNSS signal and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails.

[0184] Static positioning test module: When the train stops at a station, a static positioning test is performed based on the static deviation test algorithm to calculate the static recognition rate of the position of the secondary GNSS signal. If the static recognition rate is less than the static recognition rate threshold, the static positioning test fails. Otherwise, the static positioning test succeeds and the correction deviation is updated.

[0185] Positioning test output module: When the train reaches the destination and completes all dynamic positioning tests and static positioning tests, the positioning test results are output.

[0186] The satellite positioning test system provided in this embodiment is used to implement the satellite positioning test method in the above-mentioned embodiment 1, wherein the functions implemented by each functional module of the satellite positioning test system correspond one-to-one to each step of the satellite positioning test method; therefore, they will not be repeated here.

[0187] It should be noted that the serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments. And the terms "including", "comprising" or any other variants thereof in this article are intended to cover non-exclusive inclusion, so that a process, device, article or method 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, device, article or method. In the absence of further restrictions, an element defined by the sentence "including a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0188] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0189] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A railway-specific satellite positioning test method based on parallel multi-index, characterized in that: The following steps are involved: S1. Initialize the positions of the two GNSS receivers of the train, initialize the correction deviation, obtain the primary GNSS signal, the actual track of the train and the IMU position of the train and upload them to the positioning tester; S2. Establish a multi-source feature screening algorithm based on the primary GNSS signal, calculate the screening score, and obtain the secondary GNSS signal by screening the screening score; S3. When the train is running normally, a dynamic hierarchical test algorithm is established to perform a dynamic positioning test. First, the maximum deviation between the position of the secondary GNSS signal and the true trajectory is calculated. If the maximum deviation is less than the maximum deviation threshold, the cumulative deviation is further calculated. If the cumulative deviation is less than the cumulative deviation threshold, the cumulative deviation between the corrected position of the secondary GNSS signal and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails. S4. When the train stops at a station, a static deviation test algorithm is established to perform a static positioning test, and the static recognition rate of the position of the secondary GNSS signal is calculated. If the static recognition rate is less than the static recognition rate threshold, the static positioning test fails. Otherwise, the static positioning test succeeds and the correction deviation is updated. S5. When the train arrives at the destination and completes all dynamic positioning tests and static positioning tests, the positioning test results are output.

2. The railway-specific satellite positioning test method based on parallel multi-index according to claim 1 is characterized in that: The step S1 comprises: Two GNSS receivers are located in the first carriage of the train, called R1, and the last carriage of the train, called R2. The first-level GNSS signal is obtained through R1 and R2. The first-level GNSS signal contains position information and power information. The calculation process of the position of the first-level GNSS signal is as follows: R1 and R2 receive GNSS signals and obtain corresponding positions respectively and Where m represents the number of GNSS signals received by the GNSS receiver during the test period. represents the position of R1 when it receives the i-th GNSS signal, represents the position of R2 when it receives the i-th GNSS signal; Depend on and Calculate the position of the primary GNSS signal in, represents the train position corresponding to the i-th GNSS signal; Initialize the correction bias β; Determine the train's route and obtain the train's actual track through an electronic map; The train IMU is located in the middle of the train, that is, the middle position of the two GNSS receivers R1 and R2. The train IMU position P is calculated by the train IMU signal. IMU : Where n represents the number of train IMU signals during the test period, Indicates the train IMU position corresponding to the i-th train IMU signal; Upload the primary GNSS signal, the actual train track and the train IMU position to the positioning tester.

3. The railway-specific satellite positioning test method based on parallel multi-index according to claim 2 is characterized in that: The step S2 comprises: S21, initializing the power threshold τ and the depth threshold h; S22. Calculate the depth of the position of the primary GNSS signal The i-th level GNSS signal S23. Calculate the power fraction F g , if the power g of the i-th level GNSS signal i is greater than or equal to τ, then the i-th power fraction If the power of the i-th primary GNSS signal g i is less than τ, then the i-th power fraction S24. Calculate the first-level GNSS signal score If the position of the i-th primary GNSS signal Depth If it is greater than or equal to h or less than or equal to 0.5*h, then the i-th level 1 GNSS signal score Otherwise, the i-th level GNSS signal score S25. Calculate screening score The i-th screening score The specific expression is as follows: if If it is 2, it means that the primary GNSS signal is valid and marked as a secondary GNSS signal, otherwise the primary GNSS signal is invalid.

4. The railway-specific satellite positioning test method based on parallel multi-index according to claim 3 is characterized in that: The step S3 comprises: When the train is running normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning test: S31, Level 1 dynamic positioning test: Determine the dynamic positioning test interval and calculate the position of the secondary GNSS signal within the dynamic positioning test interval and the actual train track The deviation between Among them, m D Indicates the number of secondary GNSS signals received within the dynamic positioning test interval. represents the position of the i-th secondary GNSS signal in the dynamic positioning test interval, represents the actual position of the train at the time of the i-th GNSS signal in the dynamic positioning test section, express The depth of express Depth Calculate Deviation The maximum value of Initialize the maximum deviation threshold ρ, if it exists This indicates that the dynamic positioning test has failed, otherwise the secondary dynamic positioning test is performed; S32, Level 2 dynamic positioning test: Initialize the cumulative deviation threshold ω; If ε D ≥ω, it indicates that the dynamic positioning test has failed, otherwise the third-level dynamic positioning test is performed; S33, Level 3 dynamic positioning test:

5. The railway-specific satellite positioning test method based on parallel multi-index according to claim 3 is characterized in that: The step S4 comprises: When the train stops at a station, a static deviation test algorithm is established to perform a static positioning test: S41. The sensors in the station obtain the accurate position of the train center at each time, and obtain the train center position when it stops. Get the stop time period T s Position of the secondary GNSS signal and train IMU position S42, calculate the static recognition rate: S421. Calculate the position of the secondary GNSS signal and train center location The deviation between in, Indicates the stop time period T s The number of secondary GNSS signals within represents the position of the i-th secondary GNSS signal during the stop time period, Represents the position of the i-th secondary GNSS signal and train center location The x-axis coordinate of the deviation between Represents the position of the i-th secondary GNSS signal and train center location The y-axis coordinate of the deviation between Calculate Deviation The average Calculate Deviation Standard Deviation and S422, calculate train IMU position and train center location The deviation between in, Indicates the stop time period T s The number of in-train IMU signals, represents the train IMU position corresponding to the IMU signal of the i-th train during the stop time period, Indicates the IMU position of the i-th train and train center location The x-axis coordinate of the deviation between Indicates the IMU position of the i-th train and train center location The y-axis coordinate of the deviation between Calculate Deviation The average otherwise if and Then the flag otherwise S424: Count and obtain the position of the secondary GNSS signal The number of flag bits that are 1 Statistics get the train IMU position The number of n bits whose flag is 1 IMU-true ; S425. Calculate the position of the secondary GNSS signal Static recognition rate Calculate train IMU position The static recognition rate γ IMU-true : S426, initialize the static recognition rate threshold α2, if It means that the secondary GNSS signal static positioning test is successful. It means that the secondary GNSS signal static positioning test fails. If γ IMU-true ≥α2, it means the train IMU signal is intact. If γ IMU-true <α2, it means that there is a fault in the train IMU signal, and an alarm is prompted; S43. Update the correction deviation.

6. The railway-specific satellite positioning test method based on parallel multi-index according to claim 4 is characterized in that: The process of updating the correction deviation in step S4 includes: Get the number of positions of the secondary GNSS signal in the last dynamic positioning test cycle Where D i represents the i-th dynamic test cycle; Calculate the cumulative deviation during the last dynamic positioning test cycle in, express The depth of express Depth Calculate the cumulative average position deviation during the last dynamic positioning test cycle 7. A railway-specific satellite positioning test system based on parallel multi-index, characterized in that: Includes the following modules: Data acquisition module: initializes the positions of the two GNSS receivers of the train, initializes the correction deviation, obtains the primary GNSS signal, the actual track of the train and the position of the train IMU, and uploads them to the positioning tester; A multi-source feature screening algorithm is established based on the primary GNSS signal, the screening score is calculated, and the secondary GNSS signal is screened by the screening score; Dynamic positioning test module: When the train is running normally, a dynamic positioning test is performed based on a dynamic hierarchical test algorithm. First, the maximum deviation between the position of the secondary GNSS signal and the true trajectory is calculated. If the maximum deviation is less than the maximum deviation threshold, the cumulative deviation is further calculated. If the cumulative deviation is less than the cumulative deviation threshold, the cumulative deviation between the corrected position of the secondary GNSS signal and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails. Static positioning test module: When the train stops at a station, a static positioning test is performed based on the static deviation test algorithm to calculate the static recognition rate of the position of the secondary GNSS signal. If the static recognition rate is less than the static recognition rate threshold, the static positioning test fails. Otherwise, the static positioning test succeeds and the correction deviation is updated. Positioning test output module: When the train reaches the destination and completes all dynamic positioning tests and static positioning tests, the positioning test results are output; To realize a railway-specific satellite positioning test method based on parallel multiple indicators as described in any one of claims 1-6.

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