A method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track

Abstract

The present invention discloses a method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track, belonging to the technical field of track surveying and mapping. By connecting the mileage data measured by the inertial navigation track inspection instrument during its round-trip movement on an ultra-short track (10 meters), long-distance track deviation measurement is achieved through dead reckoning and total station deviation constraint. By analyzing the periodic repeatability of the track deviation, the accuracy evaluation of the inertial navigation track inspection instrument is ultimately realized. It is applicable to scenarios where there is no large-area track construction site or it is difficult to conduct tests on the inertial navigation track inspection instrument on the line. This method has the advantages of low cost and convenience.

Description

Technical Field

[0001] The present invention relates to the technical field of inertial navigation track inspection instrument accuracy evaluation, and particularly to a method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track. Background Art

[0002] An inertial navigation track inspection instrument is a mobile track detection device that uses an inertial navigation system and a total station / GNSS as the core measurement devices for positioning and attitude measurement, and is also equipped with sensors such as track gauge and odometer. During the measurement process, the inertial navigation track inspection instrument moves on the track, and each measurement sensor synchronously collects and records the original measurement data, which is then sent to the multi-sensor data fusion software for positioning and attitude solution to determine the six degrees of freedom information (three-dimensional position and attitude) of the movement of the inertial navigation track inspection instrument frame. Combining the measured track gauge, the three-dimensional coordinates of the track center line and the left and right rails can be calculated. Combining the track design alignment, the lateral and vertical deviation amounts of the left and right rails (referring to the track deformation amount, rather than the measurement error) can be calculated, and further various track geometric parameters such as horizontal, twist, track gauge gradient rate, and horizontal gradient rate can be obtained. The accuracy of the measured track lateral and vertical deviation amounts is the key index for evaluating the accuracy of the inertial navigation track inspection instrument.

[0003] Before the newly produced or repaired inertial navigation track inspection instrument is delivered to the user for use, the measurement accuracy of the inertial navigation track inspection instrument needs to be evaluated. Usually, measurements are carried out on the actual track, and the repeatability accuracy analysis of the measured track lateral and vertical deviation amounts of the inertial navigation track inspection instrument is performed. In order to fully test the accuracy of the inertial navigation track measurement instrument, 1 - 2 kilometers of railway track need to be measured. However, the resources of railway skylight points are very limited, and the time for normal construction and maintenance is already very tight. It is very difficult and inconvenient to coordinate the skylight points to go online for equipment testing. Building a 1 - 2 kilometer dedicated test site for the inertial navigation track inspection instrument occupies a huge area and has high construction costs. Building a railway track not longer than 10 meters can effectively solve the problems of large floor area and high cost. However, there is currently a lack of a method for evaluating the accuracy of the inertial navigation track inspection instrument using an ultra-short track. Summary of the Invention

[0004] Therefore, the purpose of the present invention is to provide a method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track. By connecting the mileage data measured by moving the inertial navigation track inspection instrument back and forth on the ultra-short track (10 meters), long-distance track deviation amount measurement is achieved through dead reckoning and total station deviation amount constraint. By analyzing the periodic repeatability of the track deviation amount, the accuracy evaluation of the inertial navigation track inspection instrument is ultimately realized, which is applicable to scenarios where there is no large-area track construction site or it is difficult to conduct tests on the inertial navigation track inspection instrument online. This method has the advantages of low cost and convenience.

[0005] In order to achieve the above object, the present invention provides a method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track, comprising:

[0006] S1. Place the total station inertial navigation track inspection device at the starting point and the end point of the ultra-short track, perform multi-point station measurement with the total station, and calculate the lateral and vertical deviations of the starting track and the lateral and vertical deviations of the end track;

[0007] S2. Push the total station inertial navigation track inspection device back and forth along the track for multiple times to obtain mileage, track gauge and inertial navigation data; after the mileage is connected, the inertial navigation data is solved to obtain time-synchronized mileage attitude data;

[0008] S3, calculating the plane coordinates and elevation of the total station inertial navigation track inspection device based on the pushing distance and mileage attitude data in S2; calculating the unconstrained track deviation according to the method for calculating the deviation in S1;

[0009] S4, calculating the constrained track deviation according to the station mileage in S1 and the unconstrained track deviation obtained in S3;

[0010] S5. Extract the lateral deviation and the vertical deviation in the constrained track deviation respectively and draw a graph to determine the periodic repeatability of the graph. If the periodic repeatability meets the preset threshold, the plane measurement accuracy and elevation measurement accuracy are met.

[0011] Further preferably, in S1, it includes:

[0012] S101, marking the starting position and the ending position at the head and the tail of the ultra-short track, placing the total station inertial navigation track inspection device at the starting and ending positions on the ultra-short track, performing multi-point station measurement, and obtaining measurement data; the measurement data includes the starting plane coordinates of the total station phase center, the starting elevation, the ending plane coordinates, and the ending elevation;

[0013] S102, calculate the plane coordinates of the starting rail surface according to the measurement data , Starting track surface elevation , the plane coordinates of the end rail surface and the terminal track elevation ;

[0014] S103, from the starting point rail plane coordinates The starting track offset is calculated by the horizontal curve of the track design line and starting mileage , from the plane coordinates of the end rail surface The end track offset is calculated by the horizontal curve of the track design line and terminal mileage ; Calculate the lateral deviation of the starting track from the starting track offset and track gauge ; Calculate the lateral deviation of the end track from the end track offset and gauge ;

[0015] S104. Calculate the designed elevation of the starting track surface from the starting mileage calculated in S103 and the vertical curve , and calculate the designed elevation of the end track surface from the end mileage and the vertical curve , from the designed elevation of the track surface and the actually measured elevation in S102 and calculate the vertical deviation of the starting track and the vertical deviation of the end track .

[0016] Further preferably, in S2, after the track is pushed back and forth multiple times, the mileage is continued according to the following formula:

[0017]

[0018] where represents the mileage at time represents the starting mileage, represents the number of times the inertial navigation track inspection instrument is pushed along the track, represents the pushing speed of the inertial navigation track inspection instrument.

[0019] Further preferably, in S3, when calculating the plane coordinates and elevation of the total station inertial navigation track inspection device, calculate according to the following formula:

[0020]

[0021] In the formula, 𝑛 is the total number of samples, E represents the east direction, N represents the north direction, U represents the elevation, represents the east coordinate, represents the north coordinate, represents the elevation, represents the initial east coordinate, represents the initial north coordinate, represents the initial elevation; represents the mileage of the kth epoch, represents the mileage of the (k - 1)th epoch; represents the heading angle of the kth epoch, represents the pitch angle of the kth epoch.

[0022] Further preferably, in S4, when calculating the constrained track deviation, the following steps are included:

[0023] S401. Interpolate the unconstrained track deviation obtained in S3 according to the instrument setup mileage in S1 to obtain the unconstrained track deviation at the instrument setup mileage of the total station.

[0024] S402. Calculate the difference between the track deviation at the instrument setup in steps S103 and S104 and the unconstrained track deviation obtained by dead reckoning.

[0025] S403. Obtain the lateral difference and vertical difference at each mileage position point according to the obtained difference and the corresponding mileage. and the vertical difference ;

[0026] S404. Calculate the constrained track deviation according to the obtained difference and the unconstrained track deviation obtained by dead reckoning, where represents the constrained lateral track deviation, represents the constrained vertical track deviation;

[0027]

[0028] where, is the lateral track deviation at the k-th epoch before constraint, is the vertical track deviation at the k-th epoch before constraint; is the lateral difference, is the vertical difference.

[0029] Further preferably, in S4, the difference between the track deviation at the instrument setup in steps S103 and S104 and the unconstrained track deviation obtained by dead reckoning is calculated according to the following formula:

[0030]

[0031] where, 、 、 、 are all the unconstrained track deviations at the instrument setup mileage; and are the differences between the lateral deviations at the instrument setup and by dead reckoning at the start and end points respectively, and are the differences between the vertical deviations at the instrument setup and by dead reckoning at the start and end points respectively.

[0032] Further preferably, in S5, to judge the periodic repeatability of the graph, the following steps are adopted:

[0033] S501. Plot the constrained lateral track deviation and analyze the periodic repeatability of the graph. If the periodic repeatability is better than 1.5 mm, the plane measurement accuracy requirements of the inertial navigation track checker are met.

[0034] S502. Plot the constrained vertical track deviation and analyze the periodic repeatability of the graph. If the periodic repeatability is better than 1.5 mm, the height measurement accuracy requirements of the inertial navigation track inspector are met.

[0035] The method for evaluating the accuracy of an inertial navigation track inspector using an ultra-short track disclosed in this application has at least the following advantages:

[0036] 1. The method for evaluating the accuracy of an inertial navigation track inspector using an ultra-short track can conveniently realize the performance evaluation of the inertial navigation track inspector after leaving the factory;

[0037] 2. This method for evaluating the inertial navigation track inspector only requires the construction of an ultra-short distance track, which has a small footprint and low cost and is easy to implement;

[0038] 3. This method for evaluating the inertial navigation track inspector does not require on-line measurement, can save valuable skylight point resources, and reduce the cost of human and material resources. Brief Description of the Drawings

[0039] Figure 1 It is a flow chart of the method for evaluating the accuracy of an inertial navigation track inspector using an ultra-short track.

[0040] Figure 2 It is a schematic diagram of placing an ultra-short track for an inertial navigation track inspector.

[0041] Figure 3 It is a mileage - lateral deviation curve graph in the analysis of the periodic repeatability of the track lateral deviation.

[0042] Figure 4 It is a mileage - elevation deviation curve graph in the analysis of the periodic repeatability of the track vertical deviation. Detailed Description of the Preferred Embodiments

[0043] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0044] A method for evaluating the accuracy of an inertial navigation track inspector using an ultra-short track proposed in this application realizes the measurement of long-distance track deviation by connecting the mileage data measured by moving the inertial navigation track detector back and forth on an ultra-short track (10 meters), and through dead reckoning and total station deviation constraint. The accuracy evaluation of the inertial navigation track inspector is finally realized by analyzing the periodic repeatability of the track deviation, as Figure 1 shown, and specifically includes the following steps:

[0045] S1. Place the total station inertial navigation track inspection device at the starting point and the ending point of the ultra-short track, conduct multi-point station setting measurement with the total station, and calculate the lateral and vertical deviation of the starting point track and the lateral and vertical deviation of the ending point track;

[0046] S2. Push the total station inertial navigation track inspection device back and forth along the track multiple times to obtain mileage, gauge, and inertial navigation data; after connecting the mileage, calculate the inertial navigation data to obtain the mileage attitude data with time synchronization.

[0047] S3. Calculate the plane coordinates and elevation of the total station inertial navigation track inspection device from the pushing distance and mileage attitude data in S2; calculate the unconstrained track deviation amount according to the method of calculating the deviation amount in S1.

[0048] S4. Calculate the constrained track deviation amount based on the set-up mileage in S1 and the unconstrained track deviation amount obtained in S3.

[0049] S5. Extract the lateral deviation amount and vertical deviation amount from the constrained track deviation amount respectively for plotting, and judge the periodic repeatability of the graph. If the periodic repeatability meets the preset threshold, the plane measurement accuracy and elevation measurement accuracy are satisfied.

[0050] When this application is implemented, as Figure 2 shown: Set a total station 2, an inertial navigation 3, and an odometer 4 on the vehicle body 1; install the vehicle body on the track 5 so that the vehicle body can move back and forth along the track.

[0051] S101. Mark the starting position and ending position at the head and tail of the ultra-short track, place the total station inertial navigation track inspection device at the starting and ending positions on the ultra-short track, and perform multi-point set-up measurement, that is, place the inertial navigation track inspection instrument equipped with a total station at the starting and ending positions on the ultra-short track, and perform total station multi-point set-up measurement. Measure 4 pairs of 8 CPⅢ control points at each station to obtain measurement data; the measurement data includes the starting plane coordinates , elevation and the ending plane coordinates , elevation ;

[0052] S102. Calculate the total station phase center starting track surface plane coordinates , starting track surface elevation , ending track surface plane coordinates and ending track surface elevation from the measurement data;

[0053] S103. Calculate the starting track offset and starting mileage from the starting track surface plane coordinates and the track design linear horizontal curve, calculate the ending track offset and ending mileage from the ending track surface plane coordinates and the track design linear horizontal curve; calculate the starting track lateral deviation amount from the starting track offset and gauge ; Calculate the lateral deviation of the end track from the end track offset and gauge ;

[0054] S104. Calculate the designed elevation of the starting track surface from the starting mileage calculated in S103 and the vertical curve , and calculate the designed elevation of the end track surface from the end mileage and the vertical curve , from the designed elevation of the track surface and the actually measured elevation in S102 and ; Calculate the vertical deviation of the starting track and the vertical deviation of the end track .

[0055] In S2, it includes:

[0056] S201. Collect data. The inertial navigation track inspection instrument is pushed back and forth along the track 31 times (310 meters) to obtain odometer, gauge, and inertial navigation data;

[0057] S202. Continuously connect the odometer data according to the following formula:

[0058] ;

[0059] Where represents the mileage at time represents the starting mileage, represents the number of times the inertial navigation track inspection instrument is pushed along the track, represents the pushing speed of the inertial navigation track inspection instrument;

[0060] S203. Inertial navigation integrated navigation solution. Use the inertial measurement algorithm model constrained by track characteristics to solve and obtain the attitude heading angle , the pitch angle , synchronize the time of the solved attitude with the mileage data obtained by the odometer to obtain the data after time synchronization of the odometer and attitude ;

[0061] S204. Resample along the mileage direction at equal mileage intervals, and use the overall least squares method for fitting with the sampling point mileage as the midpoint to obtain , where represents the number of epochs;

[0062] In S3, when calculating the plane coordinates and elevation of the total station inertial navigation track inspection device, calculate according to the following formula:

[0063]

[0064] In the formula, \(n\) is the total number of samplings, \(E\) represents the east direction, \(N\) represents the north direction, and \(U\) represents the elevation, represents the east coordinate, represents the north coordinate, represents the elevation, represents the initial east coordinate, represents the initial north coordinate, represents the initial elevation; represents the mileage at the \(k\)th epoch, represents the mileage at the \((k - 1)\)th epoch; represents the heading angle at the \(k\)th epoch, represents the pitch angle at the \(k\)th epoch.

[0065] In S4, when calculating the constrained orbit deviation amount, the following steps are included:

[0066] S401. According to the set-up mileage in S1, interpolate the unconstrained orbit deviation amount obtained in S3; obtain the unconstrained orbit deviation amount at the total station set-up mileage;

[0067] S402. Calculate the difference between the total station set-up orbit deviation amount and the dead reckoning unconstrained orbit deviation amount in steps S103 and S104; use the following formula

[0068]

[0069] where, , , , are all unconstrained orbit deviation amounts at the total station set-up mileage; and are respectively the differences between the total station set-up and dead reckoning lateral deviation amounts at the starting point and the ending point, and are respectively the differences between the total station set-up and dead reckoning vertical deviation amounts at the starting point and the ending point.

[0070] S403. According to the obtained differences, obtain the lateral difference and the vertical difference at each mileage position point according to the corresponding mileage;

[0071] S404. According to the obtained differences and the dead reckoning unconstrained orbit deviation amount, calculate the constrained orbit deviation amount, where represents the constrained lateral orbit deviation amount, represents the constrained vertical orbit deviation amount;

[0072]

[0073] where, is the lateral orbit deviation at the k-th epoch before constraint, is the vertical orbit deviation at the k-th epoch before constraint; is the lateral difference, is the vertical difference.

[0074] In S5, to determine the periodic repeatability of the graph, the following steps are adopted:

[0075] S501. Plot the lateral orbit deviation after constraint and analyze the periodic repeatability of the graph. If the periodic repeatability is better than 1.5 mm, the plane measurement accuracy requirements of the inertial navigation orbit inspector are met; as Figure 3 shown.

[0076] S502. Plot the vertical orbit deviation after constraint and analyze the periodic repeatability of the graph. If the periodic repeatability is better than 1.5 mm, the elevation measurement accuracy requirements of the inertial navigation orbit inspector are met. As Figure 4 shown.

[0077] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track, characterized in that: include: S1. Place the total station inertial navigation track inspection device at the starting point and the end point of the ultra-short track, perform multi-point station measurement with the total station, and calculate the lateral and vertical deviations of the starting track and the lateral and vertical deviations of the end track; S2. Push the total station inertial navigation track inspection device back and forth along the track for multiple times to obtain mileage, track gauge and inertial navigation data; after the mileage is connected, the inertial navigation data is solved to obtain time-synchronized mileage attitude data; S3, calculating the plane coordinates and elevation of the total station inertial navigation track inspection device based on the pushing distance and mileage attitude data in S2; calculating the unconstrained track deviation according to the method for calculating the deviation in S1; S4, calculating the constrained track deviation according to the station mileage in S1 and the unconstrained track deviation obtained in S3; In S4, the calculation of the constrained orbit deviation includes the following steps: S401, interpolating the unconstrained track deviation obtained in S3 according to the station setting mileage in S1, and obtaining the unconstrained track deviation at the station setting mileage of the total station; S402, calculating the difference between the station setting orbit deviation of the total station instrument in steps S103 and S104 and the unconstrained orbit deviation of the dead reckoning; S403, according to the obtained difference, according to the corresponding mileage, obtain the lateral difference at each mileage position point and vertical difference ; S404, calculating the constrained orbit deviation according to the obtained difference and the unconstrained orbit deviation of dead reckoning, where represents the lateral deviation of the track after constraint, Indicates the vertical deviation of the track after constraint; in, is the lateral deviation of the orbit in the kth epoch before the constraint, is the vertical orbit deviation of the kth epoch before the constraint; is the lateral difference, is the vertical difference; S5. Extract the lateral deviation and the vertical deviation in the constrained track deviation respectively and draw a graph to determine the periodic repeatability of the graph. If the periodic repeatability meets the preset threshold, the plane measurement accuracy and elevation measurement accuracy are met.

2. The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track according to claim 1 is characterized in that: In S1, it includes: S101, marking the starting position and the ending position at the head and the tail of the ultra-short track, placing the total station inertial navigation track inspection device at the starting and ending positions on the ultra-short track, performing multi-point station measurement, and obtaining measurement data; the measurement data includes the starting plane coordinates of the total station phase center, the starting elevation, the ending plane coordinates, and the ending elevation; S102, calculate the plane coordinates of the starting rail surface according to the measurement data , Starting track surface elevation , the plane coordinates of the end rail surface and the terminal track elevation ; S103, from the starting point rail plane coordinates The starting track offset is calculated by the horizontal curve of the track design line and starting mileage , from the plane coordinates of the end rail surface The end track offset is calculated by the horizontal curve of the track design line and terminal mileage ; Calculate the lateral deviation of the starting track from the starting track offset and track gauge ; Calculate the end track lateral deviation from the end track offset and track gauge ; S104, calculate the starting track surface design elevation based on the starting mileage calculated in S103 and the vertical curve The design elevation of the terminal track surface is calculated based on the terminal mileage and vertical curve. , based on the designed elevation of the track surface and the measured elevation of S102 and ; Calculate the vertical deviation of the starting track Vertical deviation from the end track .

3. The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track according to claim 1 is characterized in that: In S2, after the track is pushed back and forth multiple times, the mileage is continued according to the following formula: in, represent Time mileage, Represents the starting time mileage, Represents the number of times the inertial navigation track inspection device is pushed along the track. Indicates the pushing speed of the inertial navigation track checker.

4. The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track according to claim 1 is characterized in that: In S3, the plane coordinates and elevation of the total station inertial navigation track inspection device are calculated according to the following formula: In the formula, 𝑛 is the total number of samples, E represents the east direction, N represents the north direction, and U represents the elevation. represents the east coordinate, represents the north coordinate, Indicates elevation, represents the initial east coordinate, represents the initial north coordinate, represents the initial elevation; represents the kth epoch mileage, represents the k-1th epoch mileage; represents the heading angle at the kth epoch, represents the elevation angle at the kth epoch.

5. The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track according to claim 1 is characterized in that: In S4, the difference of the dead reckoning unconstrained orbit deviation is calculated according to the following formula: in, , , , All of them are the unconstrained track deviations at the mileage where the total station is set up; and are the difference in lateral deviation between total station setup and dead reckoning at the starting and end points, and They are the vertical deviation differences of total station setup and dead reckoning at the starting and ending points respectively.

6. The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track according to claim 1 is characterized in that: In S5, the periodic repeatability of the graph is determined by the following steps: S501, plotting the constrained lateral track deviation and analyzing the periodic repeatability of the graph. If the periodic repeatability is better than 1.5 mm, the plane measurement accuracy requirement of the inertial navigation track inspection instrument is met; S502, plot the constrained vertical track deviation and analyze the periodic repeatability of the graph. If the periodic repeatability is better than 1.5 mm, the elevation measurement accuracy requirement of the inertial navigation track inspection instrument is met.

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