Calibration method of contact network geometric parameter measuring device

Abstract

The invention discloses a calibration method of a contact network geometric parameter measuring device, assembly errors inevitably exist when sensors of the measuring device are installed, and the calibration method provided by the invention compensates the installation errors on the basis of a design installation value, so that the accuracy of a detection result is improved. The calibration method comprises the following steps: S1, selecting a plurality of measurement points on a contact line as calibration feature point positions; s2, measuring standard geometric parameter data of the calibrated feature point as target data; s3, a to-be-calibrated measuring device is adopted to acquire data of each sensor at the calibration feature point, and the data are converted into geometric parameters to serve as measurement data; and S4, finding out the optimal error compensation amount through the difference constraint function, so as to obtain the installation position compensation amount of each sensor with the minimum error between the compensated measurement data and the target data. The device can realize automatic calibration of the measuring device, is convenient for batch production, and has the characteristics of simple operation, high precision and the like.

Description

Technical Field

[0001] The invention belongs to the field of contact network parameter measurement, and in particular relates to a calibration method for a contact network geometric parameter measurement device. Background Art

[0002] In recent years, with the increase in the speed of conventional trains and the vigorous development of high-speed railway construction in my country, the construction standards of the overhead contact network that transmits electricity to electrified locomotives have become increasingly stringent, and daily maintenance tasks have become more onerous. In order to solve the problems of heavy locomotive bodies, high detection costs, low efficiency, lack of continuity, and poor stability of manual detection methods, the research on the detection method and system of contact network geometric parameters based on laser radar detection technology using high-resolution laser radar has gradually become the mainstream. Among them, the calibration of laser radar external parameters, that is, the relative position and attitude between laser radars, is crucial to improving the data fusion and measurement accuracy of the laser radar system.

[0003] However, existing methods of using lidar to measure contact network geometric parameters and calibrate measuring devices often require multiple measurements, are cumbersome to operate, and have high requirements on the environment and terrain. They rarely involve data validity control and algorithm adaptation. Summary of the invention

[0004] The present invention is proposed to solve the main problem that the existing measurement sensor calibration method is complicated. Its purpose is to provide a calibration method for a contact network geometric parameter measuring device, which can make the measurement results of the conductance value and the pull-out value more accurate.

[0005] The core technical concept of the present invention is to find out the initial design value (Xs, Zs) of the geometric coordinates of the ranging sensor in the device, and calculate the compensation coefficient S by reasonably setting multiple groups of calibration feature points. x , S z , k, α, β and γ, and use the difference constraint function to find the optimal error compensation, so as to obtain the height guide value, pull-out value and track gauge.

[0006] Specifically, the present invention provides a method for calibrating a contact network geometric parameter measuring device, comprising the following steps:

[0007] S1: Select multiple measurement points on the contact line as calibration feature points;

[0008] S2: Use the metrologically calibrated detector to measure the standard geometric parameter data of each calibration feature point as the target data. The target data specifically includes the contact line height value D i , pull out value L i and track gauge G i ;

[0009] S3: Using the measurement device to be calibrated to obtain data from the distance measuring sensor and the gauge sensor at the same calibration feature points and converting them into measurement data. The measurement data specifically includes the distance value R obtained by the distance measuring sensor. i 、Angle value θ i , and the distance value W obtained by the track gauge sensor i ;

[0010] S4: Find the optimal error compensation amount through the difference constraint function F, that is, find the installation position compensation amount of the distance sensor and the gauge sensor that minimizes the error between the compensated measurement data and the target data.

[0011] Preferably, in step S1, multiple measurement points are selected on the contact line as calibration feature points, specifically:

[0012] The calibration feature points selected on the contact line include a first measurement point set and a second measurement point set, wherein the first measurement point set includes at least a first positioning point P1 and a second positioning point P4, and the second measurement point set includes at least a first hanging string point P2 and a second hanging string point P3.

[0013] Preferably, a longitudinal section where a center line between the left rail and the right rail is located is defined as a reference datum plane;

[0014] The first positioning point P1 is located on the side of the reference datum plane facing the left rail, and the second positioning point P4 is located on the side of the reference datum plane facing the right rail; the first hanging string point P2 is located on the side of the reference datum plane facing the left rail, and the second hanging string point P3 is located on the side of the reference datum plane facing the right rail.

[0015] Preferably, the orthographic projections of the first positioning point P1 and the second positioning point P4 on the reference datum plane do not overlap, and the orthographic projections of the first hanging string point P2 and the second hanging string point P3 on the reference datum plane do not overlap;

[0016] Furthermore, the orthographic projections of the first positioning point P1 and the first hanging string point P2 on the reference datum plane do not overlap, and the orthographic projections of the second positioning point P4 and the second hanging string point P3 on the reference datum plane do not overlap.

[0017] Preferably, the metrologically calibrated detector used in step S2 is specifically a ruler or a DJJ-8 single-point laser rangefinder.

[0018] Preferably, in step S3, the measuring device to be calibrated is used to obtain data of the distance measuring sensor and the gauge sensor at the same calibration feature points and convert them into measurement data, specifically:

[0019] S31: Define the geometric coordinates of the center point of the distance measuring sensor in the measuring device as (X s , Zs ); where X s is the initial design value of the distance sensor from the left rail in the measuring device, Z s is the initial design value of the distance between the ranging sensor and the track plane;

[0020] S32: Define the straight-line distance between the center point of the ranging sensor and the calibrated feature point as R i The angle between the line between the center point of the ranging sensor and the calibration feature point and the line between the center point of the ranging sensor and its orthographic projection on the reference plane is θ i ;

[0021] S33: Define the initial design value of the gauge sensor from the left rail in the measuring device as J, and the measured value of the gauge sensor from the right rail as W i ;

[0022] S34: According to formula Z s +R i sin(θ i ) Calculate the measured value DS of the contact line height i ;

[0023] S35: According to the formula (J+W i ) / 2-R i cos(θ i )-X s Calculate the measured value LS of the contact wire pullout value i ;

[0024] S36: According to the formula J+W i Calculate the measured value of track gauge GS i .

[0025] Preferably, the distance measuring sensor used in step S3 is specifically a laser radar or a single-point laser distance measuring sensor.

[0026] Preferably, the installation position compensation amount in step S4 is specifically: α, β, γ, S x , S z , k;

[0027] The direction of the line from the center point of the ranging sensor to its orthographic projection on the reference plane is defined as the X-axis direction, the direction perpendicular to the X-axis and the track plane and extending away from the track plane is defined as the Z-axis direction, and the direction perpendicular to the X-axis and parallel to the track plane and extending away from the track plane is defined as the Y-axis direction, thus constructing an XYZ space coordinate system;

[0028] Then α is the compensation amount of the tilt angle of the ranging sensor in the ZX plane when it is installed, β is the compensation amount of the tilt angle of the ranging sensor in the ZY plane when it is installed, γ is the compensation amount of the rotation angle around the Z axis when the ranging sensor is installed, S x , S z X s , Z s is the compensation amount of the track gauge sensor.

[0029] Preferably, the measurement data is compensated in step S4, specifically:

[0030] S41: Use Formula Z s +S z +R i sin(θ i +α)coS(β)Calculate the measured value of the compensated conductivity DC i ;

[0031] S42: Use the formula (J+W i +k) / 2-R i cos(θ i +α)cos(γ)-(X s +S x ) Calculate the measured value of the compensated pull-out value LC i ;

[0032] S43: Use the formula J+W i +kCalculate the measured value of the compensated track gauge GC i .

[0033] Preferably, the difference constraint function F in step S4 is specifically:

[0034]

[0035] Where a and c are weight coefficients used to adjust the proportion of the height guide value, pull-out value and track gauge in the error function; n is the number of calibration feature points selected.

[0036] In addition, the present invention also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0037] The present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the steps of any of the aforementioned methods when executed by the processor.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The laser ranging sensor is combined with the standard value, error function and compensation amount to comprehensively measure the height value, pull-out value and track gauge of the contact network geometric parameters. The calibration model is simple, independent of the specific environment and calibration objects, and has the characteristics of simple algorithm, easy operation and high accuracy.

[0040] 2. The present invention can calibrate all error parameters through one calibration measurement without multiple calibration measurements, which greatly simplifies the calibration process and improves calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of the calibration method of the contact network geometric parameter measuring device in the present invention;

[0042] Figure 2 Schematic diagram of selecting four calibration feature points in the present invention;

[0043] Figure 3 It is a simplified diagram of the geometric relationship of the detection vehicle and the calibration process of the measuring device in the present invention.

[0044] Figure numerals: 1-contact line, 2-calibrated feature point, 3-distance measuring sensor, 4-gauge sensor, 5-left rail; 6-right rail, 7-reference datum plane. DETAILED DESCRIPTION

[0045] The technology described below can be transformed in many ways and can have many embodiments, which are described in detail with reference to the accompanying drawings in specific embodiments. However, this does not mean that the technology described below is limited to specific embodiments. It should be understood that the present invention includes all similar modifications, equivalents and substitutions without departing from the spirit and technical scope of the technology described below.

[0046] Example 1

[0047] like Figure 1 As shown, the present invention provides a calibration method for a contact network geometric parameter measuring device, which specifically includes the following steps:

[0048] S1: Select multiple measurement points on the contact line 1 as calibration feature points 2.

[0049] In step S1, the calibration feature points 2 selected on the contact line 1 include a first measurement point set and a second measurement point set, wherein the first measurement point set includes at least a first positioning point P1 and a second positioning point P4, and the second measurement point set includes at least a first hanging point P2 and a second hanging point P3. That is, the first measurement point set is composed of positioning points, and the second measurement point set is composed of hanging points.

[0050] See also Figure 2, define the longitudinal section where the center line between the left rail 5 and the right rail 6 is located as the reference datum plane 7; then the first positioning point P1 is located on the side of the reference datum plane 7 facing the left rail 5, and the second positioning point P4 is located on the side of the reference datum plane 7 facing the right rail 6; the first hanging string point P2 is located on the side of the reference datum plane 7 facing the left rail 5, and the second hanging string point P3 is located on the side of the reference datum plane 7 facing the right rail 6.

[0051] As a preferred embodiment, the orthographic projections of the first positioning point P1 and the second positioning point P4 on the reference datum plane 7 do not overlap, and the orthographic projections of the first hanging string point P2 and the second hanging string point P3 on the reference datum plane 7 do not overlap; and, the orthographic projections of the first positioning point P1 and the first hanging string point P2 on the reference datum plane 7 do not overlap, and the orthographic projections of the second positioning point P4 and the second hanging string point P3 on the reference datum plane 7 do not overlap.

[0052] More specifically, the distance from the first positioning point P1 to the reference datum plane 7 , ie, the first distance, is the same as or different from the distance from the second positioning point P4 to the reference datum plane 7 , ie, the second distance.

[0053] Similarly, the distance from the first hanging string point P2 to the reference datum plane 7, ie, the third distance, is the same as or different from the distance from the second hanging string point P3 to the reference datum plane 7, ie, the fourth distance.

[0054] The first distance and the second distance are both greater than the third distance and the fourth distance.

[0055] In a specific case, the first positioning point P1, the second positioning point P4, the first hanging string point P2 and the second hanging string point P3 are collinear.

[0056] Furthermore, for the situation where the first distance is different from the second distance, and / or the third distance is different from the fourth distance, that is, there is an asymmetry between the first positioning point P1 and the second positioning point P4, and between the first hanging string point P2 and the second hanging string point P3 in the direction perpendicular to the reference datum plane 7, two measurements are performed in the order of the first positioning point P1, the second positioning point P4, the first hanging string point P2, the second hanging string point P3, and the first positioning point P1, the first hanging string point P2, the second hanging string point P3, and the second positioning point P4, and the two measurement values ​​of the same measuring point are averaged.

[0057] Selecting the measuring points in this way helps to further eliminate the measuring errors and better realize the asymmetric correction compensation of different measuring points within the same measuring point set and between two measuring point sets at different measuring angles.

[0058] S2: Use the metrologically calibrated detector to measure the standard geometric parameter data of each calibration feature point 2 as the target data. The target data specifically includes the contact line height value Di , pull out value L i and track gauge G i .

[0059] In step S2, the contact line height value D as the target data is expanded. i , pull out value L i and track gauge G i It is the standard reference data used to calibrate the measurement data of the measuring device to be calibrated. The target data can be measured using a metrologically calibrated detector, which can be a ruler or DJJ-8 single-point laser rangefinder.

[0060] S3: Using the measurement device to be calibrated to obtain data from the distance sensor 3 and the gauge sensor 4 at the same calibration feature points 2 and converting them into measurement data. The measurement data specifically includes the distance value R obtained by the distance sensor 3. i 、Angle value θ i , and the distance value W obtained by the track gauge sensor 4 i .

[0061] In step S3, as shown in the following example, Figure 3 As shown, the measuring device to be calibrated is used to obtain the data of the distance sensor 3 and the gauge sensor 4 at the same calibration feature point 2 and convert them into measurement data, specifically:

[0062] S31: Define the geometric coordinates of the center point of the distance measuring sensor 3 in the measuring device as (X s , Z s ); where X s is the initial design value of the distance sensor 3 from the left rail 5 in the measuring device, Z s is the initial design value of the distance between the ranging sensor 3 and the track plane;

[0063] S32: define the straight-line distance between the center point of the distance measuring sensor 3 and the calibration feature point 2 as Ri, and the angle between the line connecting the center point of the distance measuring sensor 3 and the calibration feature point 2 and the line connecting the center point of the distance measuring sensor 3 and its orthographic projection on the reference datum plane 7 as θ i ;

[0064] S33: define the initial design value of the distance between the gauge sensor 4 and the left rail 5 in the measuring device as J, and the measured value of the distance between the gauge sensor 4 and the right rail 6 as Wi;

[0065] S34: According to formula Z s +R i sin(θ i ) Calculate the measured value DS of the contact line 1 i ;

[0066] S35: According to the formula (J+W i ) / 2-R i cos(θ i )-X s Calculate the measured value LS of the pull-out value of contact line 1 i ;

[0067] S36: According to the formula J+W i Calculate the measured value of track gauge GS i .

[0068] Furthermore, the distance measuring sensor 3 may specifically be a laser radar or a single-point laser distance measuring sensor.

[0069] S4: Find the optimal error compensation amount through the difference constraint function F, that is, find the installation position compensation amount of the distance sensor 3 and the gauge sensor 4 that minimizes the error between the compensated measurement data and the target data.

[0070] In step S4, in detail, the direction of the line from the center point of the ranging sensor 3 to its orthographic projection on the reference datum plane 7 is defined as the X-axis direction, the direction perpendicular to the X-axis and the orbital plane and extending away from the orbital plane is defined as the Z-axis direction, and the direction perpendicular to the X-axis and parallel to the orbital plane and extending toward the distance along the orbital plane is defined as the Y-axis direction, and an XYZ space coordinate system is constructed.

[0071] The installation position compensation amounts referred to are: α, β, γ, S x , S z , k. Wherein, α is the compensation amount of the tilt angle of the distance sensor 3 in the ZX plane when it is installed, β is the compensation amount of the tilt angle of the distance sensor 3 in the ZY plane when it is installed, γ is the compensation amount of the rotation angle around the Z axis when the distance sensor 3 is installed, S x , S z X s , Z s , k is the compensation amount of the track gauge sensor 4.

[0072] On the other hand, the compensation of the measured data refers to:

[0073] S41: Use Formula Z s +S z +R i sin(θ i +α)cos(β)Calculate the measured value of the compensated conductivity DC i ;

[0074] S42: Use the formula (J+W i +k) / 2-R icos(θ i +α)cos(γ)-(X s +S x ) Calculate the measured value of the compensated pull-out value LC i ;

[0075] S43: Use the formula J+W i +kCalculate the measured value of the compensated track gauge GC i .

[0076] Furthermore, the difference constraint function F is specifically:

[0077]

[0078] Where a, b, c are weight coefficients used to adjust the proportion of the height guide value, the pull-out value and the track gauge in the error function; n is the number of the selected calibration feature points 2.

[0079] As described above, in order to achieve a reasonable balance between efficiency and accuracy, n is generally set to 4, that is, four calibration feature points 2 are taken for measurement and calibration. The four calibration feature points can be as follows: Figure 2 The two positioning points P1 and P4 are arranged in the manner shown in the figure, and the two string hanging points P2 and P3 are located between the two positioning points P1 and P4. i The signs are opposite; and the pull-out values ​​of P2 and P3 are L i The signs are opposite.

[0080] The calibration method of the contact network geometric parameter measuring device provided by the present invention has the following beneficial effects: the calibration and correction method of the measuring sensor does not have too many requirements on the calibration terrain, and can generally be carried out in a relatively flat field. The implementation operation is simple, and less data needs to be collected, which reduces the influence of human subjective judgment and reading errors on the measurement accuracy. The measurement accuracy is high and can be reviewed and verified.

[0081] Example 2

[0082] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of any of the above-mentioned methods are implemented.

[0083] Example 3

[0084] The present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the steps of any of the aforementioned methods when executed by the processor.

[0085] According to the present invention, the program code for executing the computer program provided by the present invention can be written in any combination of one or more programming languages, specifically, these computing programs can be implemented using high-level processes and / or object-oriented programming languages ​​and / or assembly / machine languages. Programming languages ​​include but are not limited to such as Java, C++, python, "C" language or similar programming languages, and what the present invention adopts is Matlab programming software. The program code can be executed completely on the user computing device, partially on the user device, partially on the remote computing device, or completely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0086] Although the present invention has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the present invention. The above description is only a preferred embodiment of the present invention and is not limited to the scope of the present invention. Other changes and modifications made by those skilled in the art without departing from the spirit and scope of protection of the present invention are still included in the scope of protection of the present invention.

Claims

1. A calibration method for a contact network geometric parameter measuring device, characterized in that: The following steps are involved: S1: Selecting a plurality of measuring points on the contact line (1) as calibration feature points (2); S2: Use the metrologically calibrated detector to measure the standard geometric parameter data of each calibration feature point (2) as the target data. The target data specifically includes the contact line height value D i , pull out value L i and track gauge G i ; S3: Using the measurement device to be calibrated to obtain data from the distance measuring sensor (3) and the track gauge sensor (4) at the same calibration feature points (2) and converting the data into measurement data, the measurement data specifically including the distance value R obtained by the distance measuring sensor (3) i 、Angle value θ i , and the distance value W obtained by the track gauge sensor (4) i ; S4: finding the optimal error compensation amount through the difference constraint function F, that is, finding the installation position compensation amount of the distance measuring sensor (3) and the track gauge sensor (4) that minimizes the error between the compensated measurement data and the target data.

2. The calibration method of a contact network geometric parameter measuring device according to claim 1, characterized in that: In the step S1, a plurality of measuring points are selected on the contact line (1) as calibration feature points (2), specifically: The calibration feature points (2) selected on the contact line (1) include a first measurement point set and a second measurement point set, wherein the first measurement point set includes at least a first positioning point P1 and a second positioning point P4, and the second measurement point set includes at least a first hanging string point P2 and a second hanging string point P3.

3. The calibration method of a contact network geometric parameter measuring device according to claim 2, characterized in that: A longitudinal section where the center line between the left steel rail (5) and the right steel rail (6) is located is defined as a reference datum plane (7); The first positioning point P1 is located on the side of the reference datum plane (7) facing the left rail (5), and the second positioning point P4 is located on the side of the reference datum plane (7) facing the right rail (6); the first hanging string point P2 is located on the side of the reference datum plane (7) facing the left rail (5), and the second hanging string point P3 is located on the side of the reference datum plane (7) facing the right rail (6).

4. The calibration method of a contact network geometric parameter measuring device according to claim 3 is characterized in that: The orthographic projections of the first positioning point P1 and the second positioning point P4 on the reference datum plane (7) do not overlap, and the orthographic projections of the first hanging string point P2 and the second hanging string point P3 on the reference datum plane (7) do not overlap; Furthermore, the orthographic projections of the first positioning point P1 and the first hanging string point P2 on the reference datum plane (7) do not overlap, and the orthographic projections of the second positioning point P4 and the second hanging string point P3 on the reference datum plane (7) do not overlap.

5. The calibration method of a contact network geometric parameter measuring device according to claim 1, characterized in that: The metrologically calibrated detector used in step S2 is specifically a ruler or a DJJ-8 single-point laser rangefinder.

6. The calibration method of a contact network geometric parameter measuring device according to claim 1, characterized in that: In step S3, the measuring device to be calibrated is used to obtain data of the distance measuring sensor (3) and the track gauge sensor (4) at the same calibration feature points (2) and convert them into measurement data, specifically: S31: Define the geometric coordinates of the center point of the distance measuring sensor (3) in the measuring device as (x s , Z s ); where X s is the initial design value of the distance between the distance sensor (3) and the left rail (5) in the measuring device, Z s is the initial design value of the distance between the distance measuring sensor (3) and the track plane; S32: Define the straight-line distance between the center point of the distance measuring sensor (3) and the calibration feature point (2) as Ri, and the angle between the line connecting the center point of the distance measuring sensor (3) and the calibration feature point (2) and the line connecting the center point of the distance measuring sensor (3) and its orthographic projection on the reference datum plane (7) as θ i ; S33: Define the initial design value of the distance between the gauge sensor (4) and the left rail (5) in the measuring device as J, and the measured value of the distance between the gauge sensor (4) and the right rail (6) as W i ; S34: According to formula Z s +R i sin(θ i ) Calculate the measured value DS of the contact line (1) i ; S35: According to the formula (J+W i ) / 2-R i cos(θ i )-X s Calculate the measured value LS of the pull-out value of the contact line (1) i ; S36: According to the formula J+W i Calculate the measured value of track gauge GS i .

7. A calibration method for a contact network geometric parameter measuring device according to claim 6, characterized in that: The distance measuring sensor (3) used in step S3 is specifically a laser radar or a single-point laser distance measuring sensor.

8. The calibration method of a contact network geometric parameter measuring device according to claim 6, characterized in that: The installation position compensation amount in step S4 is specifically: α, β, γ, S x , S z , k; The direction of the line from the center point of the ranging sensor (3) to its orthographic projection on the reference datum plane (7) is defined as the X-axis direction, the direction perpendicular to the X-axis and the track plane and extending away from the track plane is defined as the Z-axis direction, and the direction perpendicular to the X-axis and parallel to the track plane and extending away from the track plane is defined as the Y-axis direction, thereby constructing an XYZ spatial coordinate system; Then α is the compensation amount of the tilt angle of the distance sensor (3) in the ZX plane when it is installed, β is the compensation amount of the tilt angle of the distance sensor (3) in the ZY plane when it is installed, γ is the compensation amount of the rotation angle around the Z axis when the distance sensor (3) is installed, S x , S z X s , Z s , k is the compensation amount of the track gauge sensor (4).

9. A calibration method for a contact network geometric parameter measuring device according to claim 8, characterized in that: The measurement data is compensated in step S4, specifically: S41: Use Formula Z s +S z +R i sin(θ i +α)cos(β)Calculate the measured value of the compensated conductivity DC i ; S42: Use the formula (J+W i +k) / 2-R i cos(θ i +α)cos(γ)-(X s +S x ) Calculate the measured value of the compensated pull-out value LC i ; S43: Use the formula J+W i +k Calculate the measured value of the compensated track gauge GC i .

10. A calibration method for a contact network geometric parameter measuring device according to claim 9, characterized in that: The difference constraint function F in step S4 is specifically: Where a, b, c are weight coefficients used to adjust the proportion of the height guide value, the pull-out value and the track gauge in the error function; n is the number of the selected calibration feature points (2).

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