Railway track roadbed and platform foundation displacement change measuring method and system

Abstract

The invention provides a railway track roadbed and platform foundation displacement change measurement method and system. The method comprises the steps of obtaining a measurement basis of a measured object; obtaining attitude data of the measured object, and calculating coordinates of the center position of the measured object relative to the orbit center according to the attitude data of the measured object and the geometrical relationship; obtaining a displacement change value of the track roadbed by combining the measurement basis of the measured object with the coordinate of the center position of the measured object relative to the track center; and the platform foundation displacement change is obtained according to the distance from the measured object to the platform and the measurement reference of the measured object. The method is high in measurement precision.

Description

Technical Field

[0001] The invention belongs to the field of vehicle tracks, and in particular relates to a method and a system for measuring displacement changes of railway track subgrade and platform foundation. Background Art

[0002] Gauge measurement is one of the important contents in the process of rail facility operation and maintenance, especially the measurement of platform limits, which is the key to ensure the safe operation of stations. With the increase in the number of railway platforms, on the one hand, the frequency of platform limit measurement increases, and on the other hand, in addition to the conventional horizontal, vertical and elevation dimension measurement requirements, higher requirements are also put forward. For example, in the horizontal direction, in addition to measuring the distance from the center of the track to the edge of the platform, it is also necessary to grasp the displacement changes of the track subgrade and the platform subgrade, so as to facilitate the daily operation and maintenance of the railway platform infrastructure and provide a basis for analyzing the change law of the platform limit. However, the current railway platform limit measurement methods are mainly based on single-size measurement methods such as iron ruler method, laser ranging method, visual ranging method and radar ranging method. The biggest problem with this kind of traditional measurement method is that it can only measure the relative displacement of the limit size, and cannot give the displacement changes of the track subgrade and platform foundation. Especially in cold areas, the problems of subgrade / foundation frost heave and settlement are prominent, and it is particularly important to monitor the displacement changes of the subgrade / foundation. At the same time, due to the obstruction of the railway platform canopy and the electromagnetic influence of the high-voltage contact network, the traditional method of using Beidou high-precision sensors to measure the displacement of the roadbed / base fails because it cannot receive satellite signals. In addition, some equipment such as rail trolleys with automatic measurement functions ignore the trolley posture data, which on the one hand leads to the measurement accuracy of the final limit size not meeting the standard, and on the other hand, the trolley posture data is recorded manually, making the limit size automatic measurement device based on the rail trolley lose its application value. Summary of the invention

[0003] In view of the above problems, the present invention provides a method and system for measuring displacement changes of railway track subgrade and platform foundation.

[0004] The technical solution of the present invention is as follows:

[0005] A method for measuring displacement changes of railway track subgrade and platform foundation, comprising:

[0006] Obtaining a measurement benchmark for the object being measured;

[0007] Acquire the posture data of the object to be measured, and calculate the coordinates of the center position of the object to be measured relative to the center of the track according to the posture data of the object to be measured and the geometric relationship;

[0008] The displacement change value of the track subgrade is obtained by using the measurement reference of the measured object and the coordinates of the center position of the measured object relative to the center of the track;

[0009] The change in platform foundation displacement is obtained based on the distance from the measured object to the platform and the measurement benchmark of the measured object.

[0010] Furthermore, the measurement reference of the measured object is obtained by coupling calculation between a Beidou fixed base station and an ultra-wideband fixed base station.

[0011] Specifically:

[0012] Obtain Beidou positioning data through Beidou fixed base stations and perform error compensation; obtain ultra-wideband positioning data through ultra-wideband fixed base stations and perform error compensation;

[0013] The compensated Beidou and UWB positioning data are input into the filter for fusion;

[0014] After filtering, the measurement benchmark of the object under test is generated.

[0015] Furthermore, the specific formula for calculating the coordinates of the center position of the measured object relative to the track center is as follows based on the posture data of the measured object combined with the geometric relationship:

[0016] DE=AM×cosβ-1 / 2AC

[0017] Where AC is the track gauge, β is the inclination angle, M is any point on the surface of the object being measured and AM is known data, and DE is the coordinate of the center position of the object being measured relative to the center of the track.

[0018] Furthermore, the displacement change value of the track subgrade is obtained by using the measurement reference of the measured object in combination with the coordinates of the center position of the measured object relative to the center of the track through a nonlinear least squares optimization algorithm.

[0019] Furthermore, the displacement change value of the platform foundation is obtained according to the distance from the measured object to the platform in combination with the measurement benchmark of the measured object: by using the three-side positioning algorithm, by setting three or more reference points on the platform foundation, measuring the distance from the measured object to each reference point, and then calculating the displacement change value of the platform foundation.

[0020] The present invention also provides a railway track subgrade and platform foundation displacement change measurement system, the system comprising:

[0021] Beidou fixed base station module and ultra-wideband fixed base station module are used to provide measurement benchmarks for the objects under test;

[0022] A data collection module is used to collect the posture data of the object under test;

[0023] A data transmission module, used for transmitting the posture data of the measured object to a host computer;

[0024] Host computer, used to process and display measurement results;

[0025] The power supply and management module provides power support for each component.

[0026] Further, the data collection module includes: a laser displacement sensor, a laser rangefinder, an angular tilt sensor and an ultra-wideband mobile tag;

[0027] Among them, the angle sensor is used to measure the inclination angle of the object being measured, the laser displacement sensor measures the distance between the rail wheel and the rail, the laser rangefinder is used to measure the distance from the center of the rail to the edge of the platform; the ultra-wideband mobile tag is used to communicate with the fixed base station module.

[0028] Furthermore, the laser displacement sensor is located at the wheel position of the object to be measured.

[0029] Furthermore, the host computer supports display terminals and mobile phone APPs for operation and maintenance personnel to view monitoring data in real time.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] The present invention combines BeiDou (BDS) satellite positioning and ultra-wideband (UWB) technology to achieve millimeter-level precision monitoring of track subgrade and platform foundation displacement changes, providing accurate data support.

[0032] The rail trolley of the present invention integrates an angle sensor and a laser displacement sensor to accurately obtain the trolley posture data, thereby significantly improving the measurement accuracy.

[0033] The present invention realizes automatic data collection and processing, reduces manual intervention, and displays data in real time through a host computer and a mobile phone APP, thereby improving operation and maintenance management efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings generally illustrate various embodiments by way of example and not limitation, and together with the description and claims, serve to illustrate the embodiments of the invention. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method.

[0035] Figure 1 A schematic diagram of the system of the present invention is shown, wherein 1 is a rail trolley, 2 is a first laser displacement sensor, 3 is a second laser displacement sensor, 4 is a third laser displacement sensor, 5 is a fourth laser displacement sensor, 6 is a laser rangefinder, 7 is an angle tilt sensor, 8 is a uwb mobile tag, 9 is a first Beidou-UWB base station, 10 is a second Beidou-UWB base station, 11 is a third Beidou-UWB base station, 12 is a fourth Beidou-UWB base station, 13 is a platform, 14 is a track, and 15 is a host computer;

[0036] Figure 2 A schematic diagram of the method flow of the present invention is shown;

[0037] Figure 3 A schematic diagram showing the position data of a fixed point on the surface of the track trolley of the present invention relative to the center of the track;

[0038] Figure 4 A schematic diagram of the coupling calculation process of the present invention is shown. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] like Figure 2 As shown, an embodiment of the present invention provides a method for measuring displacement changes of railway track subgrade and platform foundation, comprising:

[0041] The measurement benchmark of the rail vehicle is obtained through coupling calculation based on the base station that integrates BeiDou (BDS) and Ultra Wideband (UWB);

[0042] like Figure 4 As shown, the coupling process is: Assume that the Beidou positioning data is ρ b , uwb positioning data is ρ u , the positioning data at time k after compensation is

[0043] ρ U (k) = ρ u +ρ b +ε,

[0044] Among them, ε is the system noise;

[0045] After entering the filter coupling, we can get:

[0046] ρ U (k)=Aρ U (k-1)+ε(k),

[0047] ρ(k)=Hρ U (k)+v(k),

[0048] Among them, A is the state change data, which is 0 when it changes or 1 when it does not change, ρ U (k-1) is the linearized uwb positioning state at the previous moment, ε(k) is the noise data at moment k, ρ(k) is the real positioning data after coupling, H is the measurement data, and v(k) is the measurement error.

[0049] Obtain the posture data of the track trolley, and calculate the coordinates of the center position of the measured object relative to the center of the track based on the posture data of the track trolley and the geometric relationship, such as Figure 3 As shown;

[0050] DE=AM×cosβ-1 / 2AC

[0051] Wherein, AC is the track gauge, i.e., the distance between the two end points A and C of the track, AB is the distance between the wheel pairs of the trolley, β is the inclination angle of the trolley relative to the track, M is the position of the object to be measured on the surface of the trolley and AM is a known data, and DE is the difference between point M and the center D of the track;

[0052] The change in platform foundation displacement is obtained based on the distance from the rail trolley to the platform and the measurement benchmark of the rail trolley.

[0053] The displacement change value of the track subgrade is obtained by using the measurement reference of the measured object and the coordinates of the center position of the measured object relative to the center of the track through the nonlinear least squares optimization algorithm.

[0054] The specific steps are as follows: Assuming there are 4 base stations, the coordinates of each base station are:

[0055] s 1 =(u 1 ,v 1 ,w 1 )

[0056] s 2 =(u 2 ,v 2 ,w 2 )

[0057] s 3 =(u 3 ,v 3 ,w 3 )

[0058] s 4 =(u 4 ,v 4 ,w 4 )

[0059] The distance between the tag and each base station is: r 1 , r 2 , r 3 , r 4 ;

[0060] Let the coordinates of the label be:

[0061] m=(x,y,z)

[0062] Then the distance error between the tag and each base station is:

[0063]

[0064] Assume: The sum of square errors of all base stations is S

[0065] Then S(x,y,z)=δ 1 2 (x,y,z)+δ 2 2 (x,y,z)+δ 3 2 (x,y,z)+δ 4 2 (x,y,z)

[0066] Since S(x,y,z) is nonlinear, the goal is to optimize the minimum value of S(x,y,z). Solving m=(x,y,z) is a nonlinear least squares optimization algorithm.

[0067] The displacement change value of the platform foundation is obtained according to the distance between the measured object and the platform and the measurement benchmark of the measured object. Specifically, the displacement change value of the platform foundation is calculated by using the three-side positioning algorithm, by setting three or more reference points on the platform foundation, measuring the distance between the measured object and each reference point, and then calculating the displacement change value of the platform foundation. The specific steps are as follows:

[0068] Select three or more fixed and reasonably distributed points on the platform foundation as reference points, and accurately record the initial coordinates of each reference point;

[0069] Use a laser rangefinder or ultra-wideband positioning device installed on the object to measure the real-time distance from the object to each reference point. Taking the ultra-wideband positioning device as an example, the distance between the object and the reference point is obtained by measuring the propagation time of the signal between the object and the reference point and multiplying it by the signal propagation speed;

[0070] Assume the coordinates of the object to be measured are (x, y), and the coordinates of the three reference points are (x 1 ,y 1 )、(x 2 ,y 2 )(x 3 ,y 3 ), the measured distances are (d 1 )、(d 2 )、(d 3 ). According to the distance formula between two points

[0071] The following system of equations can be obtained:

[0072]

[0073] Transform the system of equations. Subtract the second equation from the first equation, and the third equation from the first equation, eliminate the quadratic terms, and get two linear equations about (x) and (y). Then, by combining these two linear equations, solve for the coordinates (x, y) of the object being measured.

[0074] Repeat the above steps at different times to obtain the coordinates of the object being measured at different times. Combined with the measurement benchmark of the object being measured, calculate the displacement change value of the platform foundation relative to the initial state at different times.

[0075] like Figure 1 As shown, the embodiment of the present invention also provides a railway track subgrade and platform foundation displacement change measurement system, including: a track trolley 1, a first laser displacement sensor 2, a second laser displacement sensor 3, a third laser displacement sensor 4, a fourth laser displacement sensor 5, a laser rangefinder 6, an angular tilt sensor 7, a UWB mobile tag 8, a first Beidou-UWB base station 9, a second Beidou-UWB base station 10, a third Beidou-UWB base station 11, a fourth Beidou-UWB base station 12, a platform 13, a track 14, and a host computer 15; the first laser displacement sensor 2, the second laser displacement sensor 3, and the third laser displacement sensor 4 are installed at the wheel pair of the track trolley to measure the distance of the wheel pair relative to the track. The angular tilt sensor 7 is located at the center of the track trolley, and is used to measure the tilt angle of the trolley in the vertical direction of the track, and the actual position data of the track trolley on the track is obtained by geometric calculation based on the angle value combined with the distance data of the wheel pair relative to the track. The laser rangefinder 6 is used to measure the distance from the track trolley to the platform 13 when it is at the current position, and the clearance data between the track center and the platform can be obtained in combination with the actual position data of the track trolley on the track. The first Beidou-UWB base station 9, the second Beidou-UWB base station 10, the third Beidou-UWB base station 11 and the fourth Beidou-UWB base station 12 are determined by the Beidou base station to determine the platform area foundation displacement data and provide them to the UWB base station as the reference data of the UWB mobile tag 8. When the track trolley stops at any position on the track, the UWB mobile tag 8 communicates with the first Beidou-UWB base station 9, the second Beidou-UWB base station 10, the third Beidou-UWB base station 11 and the fourth Beidou-UWB base station 12 respectively and calculates the displacement data of the UWB mobile tag 8 at the current position, and at the same time, the track roadbed displacement change data at the position can be obtained in combination with the actual position data of the track trolley on the track, and the platform foundation displacement change data can be obtained in combination with the clearance data between the track center and the platform. The host computer 15 completes the storage and processing of the measurement data, and provides host computer software for operation and maintenance personnel to view the data. At the same time, the system also provides a mobile phone APP for operation and maintenance personnel to use.

[0076] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for measuring displacement changes of railway track subgrade and platform foundation, characterized in that: include: Obtaining the measurement benchmark of the object being measured; Acquire the posture data of the object to be measured, and calculate the coordinates of the center position of the object to be measured relative to the center of the track according to the posture data of the object to be measured and the geometric relationship; The displacement change value of the track subgrade is obtained by using the measurement reference of the measured object and the coordinates of the center position of the measured object relative to the center of the track; The displacement change value of the platform foundation is obtained according to the distance from the measured object to the platform and the measurement benchmark of the measured object.

2. The method for measuring displacement changes of railway track subgrade and platform foundation according to claim 1, characterized in that: The measurement reference of the measured object is obtained by coupling calculation between the Beidou fixed base station and the ultra-wideband fixed base station, specifically: Obtain Beidou positioning data through Beidou fixed base stations and perform error compensation; obtain ultra-wideband positioning data through ultra-wideband fixed base stations and perform error compensation; The compensated Beidou and UWB positioning data are input into the filter for fusion; After filtering, the measurement benchmark of the object under test is generated.

3. The method for measuring displacement changes of railway track subgrade and platform foundation according to claim 1, characterized in that: The specific formula for calculating the coordinates of the center position of the measured object relative to the track center is as follows: DE=AM×cosβ-1 / 2AC Wherein, AC is the track gauge, β is the inclination angle, M is any point on the upper surface of the object being measured and AM is known data, and DE is the coordinate of the center position of the object being measured relative to the center of the track.

4. The method for measuring displacement changes of railway track subgrade and platform foundation according to claim 1, characterized in that: The displacement change value of the track subgrade is obtained by using the measurement reference of the measured object and the coordinates of the center position of the measured object relative to the center of the track through the nonlinear least squares optimization algorithm.

5. The method for measuring displacement changes of railway track subgrade and platform foundation according to claim 1, characterized in that: The displacement change value of the platform foundation is obtained based on the distance from the measured object to the platform and the measurement benchmark of the measured object. Specifically, the three-sided positioning algorithm is used to set three reference points on the platform foundation, measure the distance from the measured object to each reference point, and then calculate the displacement change value of the platform foundation.

6. A railway track subgrade and platform foundation displacement change measurement system, characterized in that: The system comprises: Beidou fixed base station module and ultra-wideband fixed base station module are used to provide measurement benchmarks for the objects under test; A data collection module is used to collect the posture data of the object under test; A data transmission module, used for transmitting the posture data of the measured object to a host computer; Host computer, used to process and display measurement results; The power supply and management module provides power support for each component.

7. The railway track subgrade and platform foundation displacement change measurement system according to claim 5, characterized in that: The data collection module includes: a laser displacement sensor, a laser rangefinder, an angular tilt sensor and an ultra-wideband mobile tag; Among them, the angle sensor is used to measure the inclination angle of the object being measured, the laser displacement sensor measures the distance between the rail wheel and the rail, the laser rangefinder is used to measure the distance from the center of the rail to the edge of the platform; the ultra-wideband mobile tag is used to communicate with the fixed base station module.

8. The railway track subgrade and platform foundation displacement change measurement system according to claim 6, characterized in that: The laser displacement sensor is located at the wheel position of the object to be measured.

9. The railway track subgrade and platform foundation displacement change measurement system according to claim 5, characterized in that: The host computer supports display terminals and mobile phone APPs for operation and maintenance personnel to view monitoring data in real time.

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