A parallel multi-index-based railway satellite positioning test method and system

Abstract

The application discloses a kind of railway special satellite positioning test method and system based on parallel multi-index, comprising: uploading first-level GNSS signal, train real track and train IMU position to positioning tester;Based on first-level GNSS signal, establish multi-source feature screening algorithm, calculate screening score, and obtain second-level GNSS signal from screening score;When train runs, calculate the maximum deviation between the position of second-level GNSS signal and real track, cumulative deviation and corrected cumulative deviation to realize dynamic positioning test;When train stops, calculate the static recognition rate of the position of second-level GNSS signal to realize static positioning test, and update correction deviation;Output positioning test result.The application uses multi-source feature screening algorithm to reduce the interference of redundant GNSS signal, and combines dynamic and static test, to ensure real-time while improving the accuracy of positioning test.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of positioning test technology, in particular to a railway satellite positioning test method and system based on parallel multi-index. BACKGROUND

[0002] Railway as the economic artery plays an important role in the prosperity and development of society, and railway transportation has become an indispensable means of transportation in today's society due to its rapidity and convenience. Due to its large load capacity and convenient traffic, railway transportation has played an irreplaceable role in commodity transportation and personnel communication. In the process of railway train running, it is necessary to master the running track of the train in real time to ensure the safety and efficiency of railway train operation, so the railway satellite positioning technology has gradually become the focus of researchers and front-line workers.

[0003] GNSS and Beidou signals are the most commonly used satellite positioning technology at present, and are widely used in China. How to accurately test these satellite signals and fully utilize their role in positioning is a concern of technical personnel. Although the traditional satellite positioning test method can realize basic positioning test function, it has long test cycle, few test indexes, and mostly tests dynamic scenes. In the actual process of train running, there are not only dynamic scenes but also static scenes, and different scenes have different requirements for testing. In addition, during the test process, redundant information is easily generated due to shielding and multi-path effect. These redundant information not only causes interference to the test, but also causes loss of computing power. Therefore, a new railway satellite positioning test method needs to be proposed to solve the above problems. SUMMARY

[0004] The present application provides a railway satellite positioning test method and system based on parallel multi-index to solve the technical problem of invalid GNSS signal in positioning test process and realize multi-index parallel test of static scene and dynamic scene.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

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

[0007] S1, initializing the position of two GNSS receivers of the train, initializing the correction deviation, obtaining the first-level GNSS signal, the real track of the train and the IMU position of the train and uploading them to the positioning tester;

[0008] S2, establishing a multi-source feature screening algorithm based on the first-level GNSS signal, calculating a screening score, and screening the second-level GNSS signal from the screening score;

[0009] S3, when the train is running normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning test, first, the maximum deviation between the position of the secondary GNSS signal and the real 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 position of the corrected secondary GNSS signal and the real 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 is at the station, a static deviation test algorithm is established to perform static positioning test, 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 reaches the terminal, after completing all dynamic positioning tests and static positioning tests, the positioning test result is output.

[0012] Further, the step S1 comprises:

[0013] Two GNSS receivers are respectively located at the first carriage of the train called and the last carriage of the train called , through obtaining the primary GNSS signal, the primary GNSS signal contains position information and power information, wherein the calculation process of the position of the primary GNSS signal is as follows:

[0014] Receiving GNSS signals, respectively obtaining corresponding positions and :

[0015]

[0016]

[0017] Wherein, m represents the number of GNSS signals received in the test period, represents the position when the ith GNSS signal is received, represents the position when the ith GNSS signal is received. The position of the primary GNSS signal is calculated by and

[0018] :

[0019] ​​​

[0020]

[0021] wherein, represents the position of the train corresponding to the ith GNSS signal;

[0022] initializing the correction deviation ;

[0023] determining the running route of the train, and obtaining the real trajectory of the train through an electronic map;

[0024] The train IMU is located in the middle of the train, that is, the middle position of the two GNSS receivers and The train IMU position is calculated by the train IMU signal:

[0025]

[0026] wherein, n represents the number of train IMU signals in the test period, represents the train IMU position corresponding to the ith train IMU signal;

[0027] uploading the primary GNSS signal, the real trajectory of the train and the train IMU position to a positioning tester.

[0028] It should be noted that the position of the primary GNSS signal is obtained by the two GNSS receivers jointly, so that systematic errors caused by a single receiver failure can be avoided; the correction deviation is obtained by an empirical value, and in the present application, the average value of historical tests is obtained; since the running trajectory of the train is fixed, the real trajectory can be obtained on the electronic map.

[0029] Further, the step S2 comprises:

[0030] S21, initializing the power threshold and the depth threshold h;

[0031] S22, calculating the depth of the position of the primary GNSS signal , the depth of the position of the ith primary GNSS signal is calculated as follows:

[0032]

[0033] wherein, is the x-axis coordinate of , and is the y-axis coordinate of ​the y-axis coordinate of the i-th primary GNSS signal;

[0034] S23, calculating the power score If the power of the i-th primary GNSS signal is greater than or equal to , then the i-th power score is If the power of the i-th primary GNSS signal is less than , then the i-th power score is ;

[0035] S24, calculating the primary GNSS signal score If the depth of the i-th primary GNSS signal is greater than or equal to h or less than or equal to , then the i-th primary GNSS signal score is , otherwise the i-th primary GNSS signal score is ; ;

[0036] S25, calculating the screening score The specific expression of the i-th screening score is as follows:

[0037]

[0038] If is 2, it means that the primary GNSS signal is valid and is marked as a secondary GNSS signal, otherwise the primary GNSS signal is invalid.

[0039] It should be noted that the satellite positioning test in the present application is completed on a positioning tester, so all the required position information needs to be uploaded to the positioning tester. By establishing a multi-source feature screening algorithm, joint screening can be realized by the position of the primary GNSS signal and the power of the primary GNSS signal, redundant signals can be eliminated, the interference of GNSS signals and error signals affected by shielding or multi-path effects can be reduced, the required computing power for subsequent testing can be reduced, and the testing efficiency can be improved.

[0040] Further, the step S3 comprises:

[0041] When the train is running normally, a dynamic hierarchical testing algorithm is established to perform dynamic positioning testing:

[0042] S31, primary dynamic positioning testing:

[0043] Determine the dynamic positioning test interval, calculate the deviation between the position of the secondary GNSS signal in the dynamic positioning test interval and the real track of the train ​​​​​:

[0044]

[0045] =

[0046] wherein, represents the number of secondary GNSS signals received within the dynamic positioning test interval, represents the position of the i-th secondary GNSS signal within the dynamic positioning test interval, represents the true position of the train at the i-th GNSS signal within the dynamic positioning test interval, represents the depth of ; represents the depth of ;

[0047] calculating the maximum value max of the deviation ;

[0048] initializing a maximum deviation threshold , if max exists, it indicates that the dynamic positioning test fails, otherwise, proceed to the secondary dynamic positioning test;

[0049] S32, secondary dynamic positioning test:

[0050] calculating the cumulative deviation within the dynamic positioning test interval:

[0051]

[0052] initializing a cumulative deviation threshold ;

[0053] if , it indicates that the dynamic positioning test fails, otherwise, proceed to the tertiary dynamic positioning test;

[0054] S33, tertiary dynamic positioning test:

[0055] correcting the positions of the secondary GNSS signals within the dynamic positioning test interval to obtain the corrected positions of the secondary GNSS signals :

[0056]

[0057] calculating the corrected cumulative deviation :

[0058] ​

[0059] If , it indicates that the dynamic positioning test fails, otherwise the dynamic positioning test succeeds.

[0060] It should be noted that, since the train is in a dynamic running state for a long time, the dynamic grading test algorithm is specially designed, compared with single test, through the grading way, the unqualified condition can be checked out in time, and through the dynamic positioning test of multiple indexes, the accuracy of the test can be further improved.

[0061] Further, the step S4 comprises:

[0062] When the train stops at the station, a static deviation test algorithm is established to perform static positioning test:

[0063] S41, the accurate position of the train center at each time is obtained by the sensor in the station, the position of the train center when stopping is obtained , the position of the secondary GNSS signal in the stopping time period and the train IMU position are obtained ;

[0064] S42, the static recognition rate is calculated:

[0065] S421, the deviation between the position of the secondary GNSS signal and the train center position is calculated :

[0066]

[0067]

[0068] Wherein, represents the number of secondary GNSS signals in the stopping time period, represents the position of the i-th secondary GNSS signal in the stopping time period, represents the x-axis coordinate of the deviation between the position of the i-th secondary GNSS signal and the train center position , represents the y-axis coordinate of the deviation between the position of the i-th secondary GNSS signal and the train center position ; The average value of the deviation

[0069] is calculated :

[0070] ​

[0071] Calculation deviation Standard deviation and ;

[0072] S422, calculate the train IMU position and the center of the train The deviation between :

[0073]

[0074] =

[0075] in, Indicates the stop time period The number of in-train IMU signals, Indicates 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 the center of the train The x-axis coordinate of the deviation between Indicates the IMU position of the i-th train and the center of the train The y-axis coordinate of the deviation between

[0076] Calculation deviation Average value :

[0077]

[0078] Calculation deviation Standard deviation and ;

[0079] S423, initialization deviation coefficient ,if and , then the flag bit ,otherwise ;

[0080] if and , then the flag bit ,otherwise ;

[0081] S424: Statistically obtain the position of the secondary GNSS signal The number of flag bits set to 1 , get the train IMU position by statistics The number of flag bits set to 1 ;

[0082] S425, calculating the position of the secondary GNSS signal of the static recognition rate :

[0083]

[0084] calculating the train IMU position of the static recognition rate :

[0085]

[0086] S426, initializing the static recognition rate threshold , if , indicating that the secondary GNSS signal static positioning test is successful, if , indicating that the secondary GNSS signal static positioning test fails, if , indicating that the train IMU signal is intact, if , indicating that the train IMU signal has a fault, and an alarm is prompted.

[0087] S43, updating the correction bias.

[0088] Further, the process of updating the correction bias in step S4 includes:

[0089] obtaining the number of positions of the secondary GNSS signal in the last dynamic positioning test period , wherein represents the i-th dynamic test period;

[0090] calculating the cumulative bias in the last dynamic positioning test period :

[0091]

[0092] wherein, represents the depth of , and represents the depth of ;

[0093] calculating the cumulative average position in the last dynamic positioning test period :

[0094]

[0095] updating the correction bias , wherein .

[0096] It should be noted that when the static positioning test is performed, the station information when the train stops at the station is fully utilized, so that not only the accuracy of the GNSS information can be tested, but also the fault test of the train IMU signal can be realized, thereby providing data support for the subsequent smooth operation of the train.

[0097] In addition, when the dynamic positioning test and the static positioning test are performed, the dynamic positioning test and the static positioning test at a certain time do not distinguish the dynamic positioning test or the static positioning test at the first time, but the positioning tester automatically records, and when it is needed to be used, the corresponding dynamic positioning test or static positioning test data can be automatically found.

[0098] On the other hand, the application also provides a railway special satellite positioning test system based on parallel multi-index, comprising the following modules:

[0099] The data acquisition module initializes the positions of the two GNSS receivers of the train, initializes the correction deviation, acquires the first-level GNSS signal, the real track of the train and the IMU position of the train and uploads them to the positioning tester; a multi-source feature screening algorithm is established based on the first-level GNSS signal, and the screening score is calculated, and the second-level GNSS signal is screened by the screening score;

[0100] The dynamic positioning test module: when the train is running normally, the dynamic positioning test is performed based on the dynamic hierarchical test algorithm, the maximum deviation between the position of the second-level GNSS signal and the real track is calculated first, 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 position of the second-level GNSS signal after correction and the real track is further calculated, if the cumulative deviation after correction is still less than the cumulative deviation threshold, the dynamic positioning test is successful, otherwise the dynamic positioning test fails;

[0101] The static positioning test module: when the train stops at the station, the static positioning test is performed based on the static deviation test algorithm, the static recognition rate of the position of the second-level 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;

[0102] The positioning test output module: when the train reaches the terminal and completes all dynamic positioning tests and static positioning tests, the positioning test result is output.

[0103] The technical scheme provided by the application has at least the following beneficial effects:

[0104] 1. The application adopts the combination of static positioning test and dynamic positioning test to realize the railway satellite positioning test function based on parallel multi-index, and further realizes the positioning test purpose from the static and dynamic dimensions, adopts two GNSS receivers to receive GNSS signals, avoids the systematic error caused by the failure of a single receiver, establishes a multi-source feature screening algorithm, and screens out redundant GNSS signals, especially in the shielding and multipath environment, the effect is better, compared with the traditional scheme of direct calculation, the calculation efficiency can be improved by 10% to 20%, while reducing the power consumption of the positioning tester, further reducing the hardware cost, and having obvious economic benefits.

[0105] 2. The application selects the static positioning test when the train stops at the station, establishes a static deviation test algorithm based on the train center position in the stopping time period, the position of the secondary GNSS signal and the train IMU position, calculates the static recognition rate, judges whether the static positioning test of the train at the station is successful through the static recognition rate, and further updates and corrects the deviation by using the existing resources of the station to obtain the accurate center position of the train during stopping, provides data support for subsequent dynamic positioning test, compared with the existing algorithm, the application can realize the purpose of completing multiple tests in one operation of the train, saves the cost and realizes the test of the real scene, and the test accuracy is higher than that of the simulation scene.

[0106] 3. The application adopts a dynamic hierarchical test algorithm when performing dynamic positioning test, calculates the dynamic maximum deviation to complete primary test, calculates the cumulative deviation to complete secondary test, and calculates the corrected cumulative deviation to complete tertiary test, and further realizes the rapid and accurate dynamic positioning test; in addition, the static positioning test and the dynamic positioning test are performed in parallel and alternately, and multiple indexes such as static recognition rate, dynamic maximum deviation and cumulative deviation are adopted, compared with the existing algorithm, the test indexes adopted by the application are more abundant, and the test scene is more targeted. BRIEF DESCRIPTION OF DRAWINGS

[0107] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0108] Figure 1 A flowchart of a railway satellite positioning test method based on parallel multi-index provided by the application embodiment 1. DETAILED DESCRIPTION

[0109] In order to make the purpose, technical scheme and advantages of the application more clear, the application embodiments will be further described in detail below with reference to the drawings.

[0110] Embodiment 1

[0111] This embodiment will provide a parallel multi-index-based railway satellite positioning test method provided by the application in more detail in conjunction with the corresponding drawings. As shown in the figure, the method mainly includes the following five steps: Figure 1

[0112] S1, initialize the positions of the two GNSS receivers of the train, initialize the correction bias, obtain the first-level GNSS signal, the real trajectory of the train and the IMU position of the train and upload them to the positioning tester;

[0113] S2, establish a multi-source feature screening algorithm based on the first-level GNSS signal, calculate the screening score, and screen the second-level GNSS signal from the screening score;

[0114] S3, when the train is running normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning test. First, calculate the maximum deviation between the position of the second-level GNSS signal and the real trajectory, if the maximum deviation is less than the maximum deviation threshold, then further calculate the cumulative deviation, if the cumulative deviation is less than the cumulative deviation threshold, then further calculate the cumulative deviation between the corrected position of the second-level GNSS signal and the real trajectory, if the corrected cumulative deviation is still less than the cumulative deviation threshold, then the dynamic positioning test is successful, otherwise the dynamic positioning test fails;

[0115] S4, when the train is at the station, a static deviation test algorithm is established to perform static positioning test, calculate the static recognition rate of the position of the second-level GNSS signal, if the static recognition rate is less than the static recognition rate threshold, then the static positioning test fails, otherwise the static positioning test succeeds, and the correction bias is updated;

[0116] S5, after the train reaches the terminal and completes all dynamic positioning tests and static positioning tests, output the positioning test results.

[0117] Specifically, the step S1 includes:

[0118] The two GNSS receivers are located at the first carriage of the train called and the last carriage of the train called , and the first-level GNSS signal is obtained by , which contains position information and power information, wherein the calculation process of the position of the first-level GNSS signal is as follows:

[0119] Receive GNSS signal, respectively obtain the corresponding positions and :

[0120] ​

[0121]

[0122] wherein m represents the number of GNSS signals received during the test period, the number of GNSS signals received, represents the position of the train when the ith GNSS signal is received, represents the position of the train when the ith GNSS signal is received;

[0123] is calculated by and the position of the first-order GNSS signal :

[0124]

[0125]

[0126] wherein, represents the position of the train corresponding to the ith GNSS signal;

[0127] initializing the correction deviation ;

[0128] determining the travel route of the train, and obtaining the real trajectory of the train through an electronic map;

[0129] The train IMU is located in the middle of the train, i.e. the middle position of the two GNSS receivers and The train IMU position is calculated by the train IMU signal:

[0130]

[0131] wherein n represents the number of train IMU signals during the test period, represents the position of the train IMU corresponding to the ith train IMU signal;

[0132] uploading the first-order GNSS signal, the real trajectory of the train and the train IMU position to the positioning tester.

[0133] In the application, the train IMU signal, the position of the primary GNSS signal and the position in the train real track are all the description of the same position information; since in the actual test process, the signal frequency of the IMU is often higher than that of other sensors, therefore, in the calculation, the signal of the IMU will be locally fitted, if the IMU collects 10 signals per second and the GNSS signal is 1 signal per second, in order to make the train IMU position and the position of the primary GNSS signal in quantity, the train IMU position is calculated for each signal collected by the IMU and the average value is taken, therefore, in the application, each signal corresponds to a position, that is, the signal quantity and the position quantity are consistent.

[0134] The step S2 comprises:

[0135] S21, initializing the power threshold value and the depth threshold value h;

[0136] S22, calculating the depth of the position of the primary GNSS signal The depth of the position of the i-th primary GNSS signal The specific expression is as follows:

[0137]

[0138] Among them, is the x-axis coordinate of , and is the y-axis coordinate of ;

[0139] S23, calculating the power score If the power of the i-th primary GNSS signal is greater than or equal to , the i-th power score If the power of the i-th primary GNSS signal is less than , the i-th power score ;

[0140] S24, calculating the primary GNSS signal score If the depth of the position of the i-th primary GNSS signal is greater than or equal to h or less than or equal to , the i-th primary GNSS signal score , otherwise the i-th primary GNSS signal score ;

[0141] S25, calculating the screening score The i-th screening score ​​The specific expression is as follows:

[0142]

[0143] If is 2, it means that the primary GNSS signal is valid and is marked as a secondary GNSS signal, otherwise the primary GNSS signal is invalid.

[0144] The step S3 comprises:

[0145] When the train is running normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning test:

[0146] S31, primary dynamic positioning test:

[0147] Determine the dynamic positioning test interval, calculate the position of the secondary GNSS signal in the dynamic positioning test interval and the deviation between the real track of the train :

[0148]

[0149] =

[0150] Wherein, represents the number of secondary GNSS signals received in the dynamic positioning test interval, represents the position of the i-th secondary GNSS signal in the dynamic positioning test interval, represents the real position of the train at the i-th GNSS signal in the dynamic positioning test interval, represents the depth of , and represents the depth of ;

[0151] Calculate the maximum value max of the deviation ;

[0152] Initialize the maximum deviation threshold , if max exists, it means that the dynamic positioning test fails, otherwise proceed to the secondary dynamic positioning test;

[0153] S32, secondary dynamic positioning test:

[0154] Calculate the cumulative deviation in the dynamic positioning test interval:

[0155]

[0156] Initialize the cumulative deviation threshold ;

[0157] if , it indicates that the dynamic positioning test has failed, otherwise the third-level dynamic positioning test is carried out;

[0158] S33, Level 3 dynamic positioning test:

[0159] The position of the secondary GNSS signal within the dynamic positioning test area Perform correction to obtain the corrected position of the secondary GNSS signal :

[0160]

[0161] Calculate the corrected cumulative deviation :

[0162]

[0163] if , it indicates that the dynamic positioning test fails, otherwise the dynamic positioning test succeeds;

[0164] It should be further explained that due to The value can be positive or negative. If the second level test is performed, it can also be The positive or negative value of the value directly determines whether to conduct the third level test. If the third level dynamic positioning test is required during the second test, If it is greater than or equal to zero, the dynamic positioning test can be directly judged to have failed. If it is less than zero, the calculation proceeds normally.

[0165] The step S4 comprises:

[0166] When the train stops at a station, a static deviation test algorithm is established to perform static positioning test:

[0167] S41. The sensors in the station obtain the accurate position of the train center at each moment and the train center position when it stops. , get the docking time period Position within secondary GNSS signal and train IMU position ,in Indicates the status of the train when it stops at the station;

[0168] S42. Calculate the static recognition rate:

[0169] S421. Calculate the position of the secondary GNSS signal and the center of the train The deviation between :

[0170]

[0171]

[0172] in, Indicates the stop time period The number of secondary GNSS signals within, represents the position of the i-th secondary GNSS signal during the docking period, Indicates the position of the i-th secondary GNSS signal and the center of the train The x-axis coordinate of the deviation between , express The x-axis coordinate, express The x-axis coordinate, Indicates the position of the i-th secondary GNSS signal and the center of the train The y-axis coordinate of the deviation between , express The y-axis coordinate, express The y-axis coordinate;

[0173] Calculation deviation Average value :

[0174]

[0175] Calculation deviation Standard deviation and ;

[0176] S422, calculate the train IMU position and the center of the train The deviation between :

[0177]

[0178] =

[0179] in, Indicates the stop time period The number of in-train IMU signals, Indicates 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 the center of the train The x-axis coordinate of the deviation between Indicates the IMU position of the i-th train and the center of the train The y-axis coordinate of the deviation between

[0180] Calculation deviation Average value :

[0181]

[0182] Calculation deviation Standard deviation and ;

[0183] S423, initialization deviation coefficient ,if and , then the flag bit ,otherwise ;

[0184] if and , then the flag bit ,otherwise ;

[0185] S424: Statistically obtain the position of the secondary GNSS signal The number of flag bits set to 1 , get the train IMU position by statistics The number of flag bits set to 1 ;

[0186] S425. Calculate the position of the secondary GNSS signal Static recognition rate :

[0187]

[0188] Calculate the train IMU position Static recognition rate :

[0189]

[0190] S426: Initialize static recognition rate threshold ,if , it means the secondary GNSS signal static positioning test is successful. If , it means that the secondary GNSS signal static positioning test has failed. If , it is indicated that the train IMU signal is intact, if , it is indicated that the train IMU signal has a fault, and an alarm is prompted.

[0191] S43, updating the correction bias:

[0192] Obtain the position quantity of the secondary GNSS signal in the last dynamic positioning test period , wherein indicates the i-th dynamic test period;

[0193] Calculate the cumulative bias in the last dynamic positioning test period :

[0194]

[0195] , wherein indicates the depth of , wherein indicates the depth of ;

[0196] Calculate the cumulative average position in the last dynamic positioning test period :

[0197]

[0198] Update the correction bias , wherein .

[0199] In the present application, by designing a dynamic hierarchical test algorithm, the inaccurate dynamic positioning test can be found in time, if the first level test is unqualified, subsequent tests do not need to be performed, avoiding the disadvantage that all test processes must be completed to analyze the test result, reducing the demand of the test method on the computing power, and further reducing the hardware cost of the positioning tester.

[0200] The present application adopts a parallel multi-index test method combining multiple dynamic positioning tests and static positioning tests, realizes positioning test of the railway special satellite signal, the test scene is more close to the actual operation scene of the train, the test efficiency is higher, and the test result is more accurate.

[0201] Embodiment 2

[0202] The present embodiment provides a railway special satellite positioning test system based on parallel multi-index, mainly including the following four modules:

[0203] The data acquisition module: initializes the positions of the two GNSS receivers of the train, initializes the correction bias, acquires the first-level GNSS signal, the real trajectory of the train and the IMU position of the train and uploads them to the positioning tester; establishes a multi-source feature screening algorithm based on the first-level GNSS signal, calculates the screening score, and screens the second-level GNSS signal based on the screening score;

[0204] The dynamic positioning test module: when the train is running normally, dynamic positioning test is performed based on the dynamic hierarchical test algorithm, first, the maximum deviation between the position of the second-level GNSS signal and the real trajectory is calculated, if the maximum deviation is less than the maximum deviation threshold, then the cumulative deviation is further calculated, if the cumulative deviation is less than the cumulative deviation threshold, then the cumulative deviation between the corrected second-level GNSS signal and the real trajectory is further calculated, if the corrected cumulative deviation is still less than the cumulative deviation threshold, then the dynamic positioning test is successful, otherwise the dynamic positioning test fails;

[0205] The static positioning test module: when the train is parked at the station, static positioning test is performed based on the static deviation test algorithm, the static recognition rate of the position of the second-level GNSS signal is calculated, if the static recognition rate is less than the static recognition rate threshold, then the static positioning test fails, otherwise the static positioning test succeeds, and the correction bias is updated;

[0206] The 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.

[0207] The satellite positioning test system provided by the 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 to each step of the satellite positioning test method one by one; therefore, no further description is given here.

[0208] It should be noted that the serial numbers of the above-mentioned embodiments of the application are only for description, and do not represent the advantages and disadvantages of the embodiments. Moreover, the terms "include", "contain" or any other variants thereof in this article are intended to cover non-exclusive inclusion, so that the process, device, article or method including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, device, article or method. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, device, article or method including the element.

[0209] Those skilled in the art can clearly understand the above-mentioned embodiment method can be realized by means of software and the necessary general hardware platform, of course, also can be through hardware, but in many cases the former is the better embodiment. Based on such understanding, the technical solutions of the present application essentially or say the part of the contribution to the prior art can be embodied in the form of software products, the computer software product is stored in a storage medium (such as ROM / RAM, magnetic disc, optical disc) as described above, including a number of instructions to make a terminal device (may be a mobile phone, computer, server, or network equipment, etc.) executes the method described in various embodiments of the present application.

[0210] The above is only the preferred embodiment of the present application, not therefore limit the patent scope of the present application, any equivalent structure or equivalent flow transformation made by using the content of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

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 on the train, initialize the correction deviation, obtain the first-level GNSS signal, the actual train trajectory and the train IMU position, 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 based on the screening score; S3. When the train is operating 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 succeeds; 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 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. 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. and the last car of the train is called ,pass A primary GNSS signal is obtained, where the primary GNSS signal includes position information and power information. The position of the primary GNSS signal is calculated as follows: Receive GNSS signals and obtain corresponding positions and : Among them, m represents the test time period The number of GNSS signals received, express The position when receiving the i-th GNSS signal, express The position when receiving the i-th GNSS signal; Depend on and Calculate the position of the first-level GNSS signal : in, represents the train position corresponding to the i-th GNSS signal; Initialize correction deviation ; Determine the train's route and obtain the train's actual trajectory through an electronic map; The train IMU is located in the middle of the train, that is, two GNSS receivers and The middle position of the train IMU is calculated by the train IMU signal : 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 first-level GNSS signal, the actual train trajectory 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. Initialize power threshold and depth threshold h; S22. Calculate the depth of the position of the primary GNSS signal , the position of the i-th level GNSS signal Depth The specific expression is as follows: in, for The x-axis coordinate, for The y-axis coordinate of S23. Calculate power score , if the power of the i-th level GNSS signal Greater than or equal to , then the i-th power fraction , if the power of the i-th level GNSS signal Less than , then the i-th power fraction ; S24. Calculate the first-level GNSS signal score , if the position of the i-th level GNSS signal Depth Greater than or equal to h or less than or equal to , then the i-th level 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 operating normally, a dynamic hierarchical test algorithm is established to perform dynamic positioning tests: 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 : = in, Indicates the number of secondary GNSS signals received within the dynamic positioning test interval. represents the position of the i-th secondary GNSS signal within 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, express Depth; Calculation deviation The maximum value max ; Initialize the maximum deviation threshold , if there is a max , it indicates that the dynamic positioning test has failed, otherwise the secondary dynamic positioning test is carried out; S32, Level 2 dynamic positioning test: Calculate the cumulative deviation within the dynamic positioning test interval : Initialize the cumulative deviation threshold ; if , it indicates that the dynamic positioning test has failed, otherwise the third-level dynamic positioning test is carried out; S33, Level 3 dynamic positioning test: The position of the secondary GNSS signal within the dynamic positioning test area Perform correction to obtain the position of the corrected secondary GNSS signal : Calculate the corrected cumulative deviation : if , it indicates that the dynamic positioning test fails, otherwise the dynamic positioning test succeeds.

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 static positioning test: S41. The sensors in the station obtain the accurate position of the train center at each moment and the train center position when it stops. , get the docking time period Position within secondary GNSS signal and train IMU position ; S42. Calculate the static recognition rate: S421. Calculate the position of the secondary GNSS signal and the center of the train The deviation between : in, Indicates the stop time period The number of secondary GNSS signals within, represents the position of the i-th secondary GNSS signal during the docking period, Indicates the position of the i-th secondary GNSS signal and the center of the train The x-axis coordinate of the deviation between Indicates the position of the i-th secondary GNSS signal and the center of the train The y-axis coordinate of the deviation between Calculation deviation Average value : Calculation deviation Standard deviation and ; S422, calculate the train IMU position and the center of the train The deviation between : = in, Indicates the stop time period The number of in-train IMU signals, Indicates 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 the center of the train The x-axis coordinate of the deviation between Indicates the IMU position of the i-th train and the center of the train The y-axis coordinate of the deviation between Calculation deviation Average value : Calculation deviation Standard deviation and ; S423, initialization deviation coefficient ,if and , then the flag bit ,otherwise ; if and , then the flag bit ,otherwise ; S424: Statistically obtain the position of the secondary GNSS signal The number of flag bits set to 1 , get the train IMU position by statistics The number of flag bits set to 1 ; S425. Calculate the position of the secondary GNSS signal Static recognition rate : Calculate the train IMU position Static recognition rate : S426: Initialize static recognition rate threshold ,if , it means the secondary GNSS signal static positioning test is successful. If , it means that the secondary GNSS signal static positioning test has failed. If , it means the train IMU signal is intact. If , it means that there is a fault in the train IMU signal and an alarm prompts; 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 ,in represents the i-th dynamic test cycle; Calculate the cumulative deviation during the last dynamic positioning test cycle : in, express The depth, express Depth; Calculate the cumulative average position during the last dynamic positioning test cycle : Update correction bias ,in .

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 on the train, initializes the correction deviation, obtains the first-level GNSS signal, the actual train trajectory and the train IMU position, and uploads them to the positioning tester; A multi-source feature screening algorithm is established based on the primary GNSS signal, and the screening score is calculated. The secondary GNSS signal is then screened based on the screening score. Dynamic positioning test module: When the train is operating normally, a dynamic positioning test is performed based on the 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 secondary GNSS signal position and the true trajectory is further calculated. If the corrected cumulative deviation is still less than the cumulative deviation threshold, the dynamic positioning test succeeds; 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, it outputs the positioning test results; 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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