Method for evaluating precision of inertial navigation track inspection tester by using ultra-short track

Abstract

The invention discloses a method for evaluating the precision of an inertial navigation track detector by using an ultra-short track, which belongs to the technical field of track surveying and mapping, and is characterized in that mileage data measured by reciprocating movement of the inertial navigation track detector on the ultra-short track (10 meters) is continued, and long-distance track deviation value measurement is realized through dead reckoning and total station deviation value constraint. The precision evaluation of the inertial navigation track inspection tester is finally realized by analyzing the repeatability of the track deviation value period, the method is suitable for a site without large-area track construction or a scene in which the inertial navigation track inspection tester is difficult to test on line, and the method has the advantages of low cost and convenience.

Description

Technical Field

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

[0002] The inertial navigation track inspection instrument is a mobile track inspection equipment that uses an inertial navigation system and a total station / GNSS as core measurement equipment for positioning and attitude measurement. It is also equipped with sensors such as 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 inertial navigation track inspection instrument frame movement. Combined with the measured gauge, the three-dimensional coordinates of the track centerline and the left and right rails can be calculated. Combined with the track design line type, the lateral and vertical deviations of the left and right rails are calculated (referring to the deformation of the track, not the measurement error), and the various track geometric parameters such as level, distortion, gauge change rate, and horizontal change rate are further obtained. The accuracy of the measured lateral and vertical deviations of the track is a key indicator for the accuracy assessment of the inertial navigation track inspection instrument.

[0003] Before the newly produced or repaired inertial navigation track inspection instrument is delivered to the user, the measurement accuracy of the inertial navigation track inspection instrument needs to be evaluated. Usually, the measurement is carried out on the actual track, and the horizontal and vertical deviations of the measured track of the inertial navigation track inspection instrument are repeatedly analyzed for accuracy. In order to fully test the accuracy of the inertial navigation track measuring instrument, 1 to 2 kilometers of railway tracks need to be measured, but the resources of railway skylight points are very limited, and the time for normal construction and maintenance is often very tight. It is very difficult and inconvenient to coordinate the skylight points to go online for equipment testing. The construction of a 1 to 2 km dedicated inertial navigation track inspection instrument test site occupies a huge area and is expensive. The construction of a railway track no longer than 10 meters can effectively solve the problem of large area and high cost, but there is currently a lack of a method for evaluating the accuracy of inertial navigation track inspection instruments using ultra-short tracks. 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. The method connects the mileage data measured by the round-trip movement of the inertial navigation track inspection instrument on the ultra-short track (10 meters), realizes the measurement of long-distance track deviation through dead reckoning and total station deviation constraints, and finally realizes the accuracy evaluation of the inertial navigation track inspection instrument by analyzing the periodic repeatability of the track deviation. The method is suitable for scenarios where there is no large-scale track construction site or it is difficult to test the inertial navigation track inspection instrument online. The 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: 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; 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.

[0006] Further preferably, 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 ; The lateral deviation of the terminal track is calculated from the terminal 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 .

[0007] Further preferably, 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.

[0008] Further preferably, in S3, when calculating the plane coordinates and elevation of the total station inertial navigation track inspection device, the following formula is used: In the formula, 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 pitch angle at the kth epoch

[0009] Further preferably, in S4, when calculating the constrained track deviation, the following steps are included: 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 orbit deviation of 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.

[0010] Further preferably, in S4, the difference between the total station set track deviation and the dead reckoning unconstrained track deviation in steps S103 and S104 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.

[0011] Further preferably, 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.

[0012] The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track disclosed in the present application has at least the following advantages: 1. The method of using ultra-short track to evaluate the accuracy of the inertial navigation track inspection instrument can conveniently realize the performance evaluation of the inertial navigation track inspection instrument after leaving the factory; 2. The inertial navigation track inspection instrument assessment method only requires the construction of ultra-short distance tracks, which occupies a small area and is low in cost, and is easy to implement; 3. The inertial navigation track inspection instrument assessment method does not require online measurement, which can save precious skylight point resources and reduce manpower and material costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a flow chart of the accuracy assessment method for inertial navigation track inspection instrument using ultra-short tracks.

[0014] Figure 2 Schematic diagram of placing an ultra-short track for the inertial navigation track checker.

[0015] Figure 3 This is the mileage-lateral deviation curve in the periodic repeatability analysis of track lateral deviation.

[0016] Figure 4 This is the mileage-elevation deviation curve in the periodic repeatability analysis of track vertical deviation. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below through the accompanying drawings and specific embodiments.

[0018] This application proposes a method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track. The mileage data measured by the inertial navigation track inspection instrument moving back and forth on an ultra-short track (10 meters) is connected, and the long-distance track deviation measurement is realized through dead reckoning and total station deviation constraint. The accuracy of the inertial navigation track inspection instrument is finally evaluated by analyzing the periodic repeatability of the track deviation. Figure 1 As shown, the specific steps 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; 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.

[0019] When this application is implemented, Figure 2As shown: a total station 2, an inertial navigation system 3 and an odometer 4 are arranged on a vehicle body 1; the vehicle body is installed on a track 5 so that the vehicle body can move back and forth along the track.

[0020] S101. Mark the starting and ending positions 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 station measurement, that is, place the inertial navigation track inspection device equipped with the total station at the starting and ending positions on the ultra-short track, and perform multi-point station measurement with the total station, measuring 4 pairs of 8 CPⅢ control points at each station to obtain measurement data; the measurement data includes the plane coordinates of the starting point , Elevation and the end point plane coordinates , Elevation ; S102. Calculate the plane coordinates of the starting point of the total station phase center based on 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 ; The lateral deviation of the terminal track is calculated from the terminal 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 .

[0021] In S2, it includes: S201, data collection: the inertial navigation track inspection instrument is pushed back and forth 31 times (310 meters) along the track to obtain odometer, track gauge and inertial navigation data; S202, the mileage meter data is connected 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 inspection instrument; S203, inertial navigation integrated navigation solution, using the inertial measurement algorithm model constrained by orbital characteristics to solve and obtain the attitude and heading angle , pitch angle , the solved attitude and the mileage data obtained by the odometer Perform time synchronization to obtain odometer and attitude time synchronized data ; S204, will Resample along the mileage direction at equal mileage intervals, and use the overall least squares method to fit with the sampling point mileage as the midpoint to obtain ,in represents the epoch number; 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, 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 pitch angle at the kth epoch.

[0022] 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, calculate the difference between the total station set track deviation in steps S103 and S104 and the dead reckoning unconstrained track deviation; use 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.

[0023] 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 orbit deviation of 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.

[0024] In S5, the periodic repeatability of the graph is determined by the following steps: 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 requirement of the inertial navigation track inspection instrument is met; Figure 3 shown.

[0025] 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. Figure 4 shown.

[0026] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the 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; 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, 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 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.

6. The method for evaluating the accuracy of an inertial navigation track inspection instrument using an ultra-short track according to claim 5 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.

7. 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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