A method for correcting parking space when the positioning antenna is installed off-center.

Abstract

This invention discloses a method for correcting locomotive positioning when the installation of a positioning antenna is offset. The method includes measuring the longitudinal and lateral distances of the locomotive antenna from the center point of the locomotive's I-end head, setting these distances as configuration parameters; converting the BeiDou coordinate values ​​to Cartesian coordinates using Miller projection; determining the orientation of the tracks on the actual latitude and longitude map based on the changing trends of track mapping data in the station diagram; determining whether the locomotive coordinate point is above or below the track using a formula in the Cartesian coordinate system; and compensating for the vertical distance of each track in the station diagram based on the locomotive's coordinate point's orientation, the locomotive's I-end head orientation, the track orientation, and the antenna configuration parameters, finding the track with the minimum vertical distance value, and calculating the track position of the locomotive's head. This method effectively eliminates the influence of the antenna installation position, improving the accuracy and matching success rate of real-time locomotive positioning.

Description

Technical Field

[0001] This invention belongs to the field of rail transit train safety protection and control technology, specifically relating to a method for correcting the vehicle position when the positioning antenna is installed off-center. Background Technology

[0002] The shunting operation safety auxiliary protection system, or simply the shunting protection system, requires determining the locomotive's position in the station yard based on BeiDou positioning coordinates. This system protects against closing signals from forward signals, station boundaries, and earth barriers. However, the installation position of the BeiDou positioning antenna is not fixed due to the spatial layout on top of the locomotive. When the antenna is not installed on the locomotive's central axis, the coordinates surveyed in the station yard are based on the centerline of the track. The precise positioning coordinates received by the locomotive will deviate from the centerline, which will interfere with determining the locomotive's position.

[0003] Since the distance between adjacent straight tracks in a station yard is typically around 5 meters, the maximum vertical distance for locomotive positioning is less than 2.5 meters. For the section after a turnout, the vertical distance threshold for the system to determine the locomotive's direction must be even lower than 1 meter. Positioning errors will occur if the antenna deviates from the locomotive's center axis by more than 1 meter. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a method for correcting the car position when the positioning antenna is installed off-center, thereby eliminating the influence of the antenna installation position and improving the control accuracy of the shunting protection system during locomotive operation.

[0005] The specific plan is as follows:

[0006] A method for correcting parking space misalignment when the positioning antenna is installed off-center includes the following steps:

[0007] S1): Measure the distance between the antenna position on the locomotive and the center point of the locomotive I end, the distance including longitudinal distance and lateral distance, and set the longitudinal distance and lateral distance as configuration parameters;

[0008] S2): Convert the BeiDou coordinate values ​​to coordinate values ​​in a rectangular coordinate system using the Miller projection method;

[0009] S3): Based on the changing trend of track mapping data in the station schematic diagram, determine the orientation of the track in the actual latitude and longitude map; S4): In the rectangular coordinate system, use a formula to determine whether the locomotive coordinate point is above or below the track;

[0010] S5): Based on the locomotive coordinates, locomotive head orientation, track orientation, and antenna configuration parameters, the vertical distance of each track in the station map is adjusted by addition or subtraction.

[0011] S6): Compare the compensated vertical distances of each track, obtain the minimum value of the compensated vertical distance, and calculate the track position of the train head based on the track corresponding to the track with the minimum compensated vertical distance value.

[0012] Step S4) involves using a formula to determine whether the locomotive's coordinates are above or below the track, and includes the following steps:

[0013] S41): Take any two points on the track and convert the two points on the track and the locomotive position into coordinates in a rectangular coordinate system;

[0014] S42): In a rectangular coordinate system, a linear function passing through two points is obtained based on the coordinates of two points taken on the track;

[0015] S43): Substitute the rectangular coordinates of the locomotive position into the linear function and determine the relationship between the value of the linear function and zero. If the value of the linear function is equal to zero, the locomotive position is located on the line connecting the two points of the track. If the value of the linear function is greater than zero, the locomotive position is located above the line connecting the two points of the track. If the value of the linear function is less than zero, the locomotive position is located below the line connecting the two points of the track.

[0016] The method for adding or subtracting compensation for the vertical distance of each track in step S5) includes the following steps;

[0017] S51): Set the locomotive coordinates as P0 (x0, y0), the left end point coordinates of the track as D1 (x1, y1), the right end point coordinates as D2 (x2, y2), the line connecting the left end point coordinates of the track as D1 and the right end point coordinates of the track as line, and the perpendicular distance from the locomotive coordinate P to line as h1.

[0018] S52): Determine if x1 is greater than x2. If it is, the track needs to be reversed, and the value of the vertical distance h1 is -h1.

[0019] S53): Determine whether the locomotive coordinate P0 is below the straight line. If it is below the straight line, the value of the perpendicular distance h1 is -h1.

[0020] S54): Determine whether locomotive head I is to the right of locomotive head II. If it is, the value of the vertical distance h1 is h1+H. If it is not, the value of the vertical distance h1 is h1-H. Where H is the longitudinal distance of the locomotive antenna from the center point of locomotive head I.

[0021] S55): Obtain the absolute value of the perpendicular distance h1 in step S54) to get the compensated perpendicular distance H1=abs(h1);

[0022] The method for calculating the position of the locomotive in the track includes the following steps:

[0023] S61): Set the track corresponding to the minimum vertical distance value after compensation as G, that is, track G is the track number where the locomotive is located. Calculate the distance between the locomotive antenna point P and the two ends D1 and D2 of track G based on the latitude and longitude of the locomotive antenna point P and track G.

[0024] S62): Subtract the lateral distance from the distance between the locomotive antenna point P and the two ends of track G to obtain the distance between the locomotive I end head and the two ends of track G, that is, the position of the locomotive head on the track.

[0025] This invention discloses a method for correcting locomotive positioning when the positioning antenna is installed at an offset. When the locomotive positioning antenna is installed at an offset, the locomotive positioning is corrected, which can effectively eliminate the influence of the antenna installation position and improve the accuracy of the locomotive's real-time positioning. Attached Figure Description

[0026] Figure 1 This is a schematic diagram showing the positioning of the track and locomotive antenna.

[0027] Figure 2 This is a structural diagram of the locomotive and positioning antenna.

[0028] Figure 3 This is a schematic diagram of the station.

[0029] Figure 4 This is a schematic diagram showing the positional relationship between point P and line L1. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the implementation of the present invention, and not all of it. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, the locomotive is traveling on track 1 at this time. However, due to the offset of the installation position of the positioning antenna on the locomotive, when the positioning antenna is used for positioning, it will be found that the positioning antenna is closer to track 2 and farther away from track 1, resulting in an incorrect positioning of the locomotive traveling on track 1. In order to eliminate the influence of the antenna installation position and improve the accuracy of the locomotive's real-time positioning, the present invention provides a method for correcting the locomotive position when the positioning antenna installation is offset.

[0032] A method for correcting parking space misalignment when the positioning antenna is installed off-center includes the following steps:

[0033] S1): Measure the distance between the antenna position on the locomotive and the center point of the locomotive I end, the distance including longitudinal distance and lateral distance, and set the longitudinal distance and lateral distance as configuration parameters;

[0034] like Figure 2 As shown, the length of the locomotive head is W, and the width of the locomotive head is 2S. When installing the antenna, measure the longitudinal distance H and the lateral distance L between the locomotive antenna and the center point of the locomotive head at end I. Set H and L as configuration parameters, with L ranging from 0 to W and H ranging from -S to S, in centimeters. With the driver's cab at end I as the direction of travel, when the locomotive driver is facing the windshield of the driver's cab at end I, the direction where the driver's left hand is located is set as the positive direction, and the direction where the driver's right hand is located is set as the negative direction.

[0035] S2): Convert the BeiDou coordinate values ​​to coordinate values ​​in a rectangular coordinate system using the Miller projection method;

[0036] Because the Earth is an ellipse, the latitude and longitude coordinates measured are not planar coordinates, so they need to be converted to planar coordinates before they can be used in calculations. The Miller projection method assumes that there is a cylinder perpendicular to the equator placed on the Earth, and then a light is lit at the Earth's center. The light projects various points on the Earth onto the cylinder. Then, the cylinder is unfolded to obtain the planar projection of the sphere.

[0037] Converting BeiDou coordinates to Cartesian coordinates can be done using the Miller projection method. For example, converting latitude and longitude coordinates (JD, WD) to Cartesian coordinates (X, Y) is as follows:

[0038] Let the Earth's circumference be L0, then L0 = 6381372 * π * 2; where π is the mathematical constant pi.

[0039] After the plane is unfolded, the length of the x-axis, Wx, is equal to the perimeter, Wx = L0;

[0040] The length of the y-axis, Hy, is approximately equal to half the circumference, Hy = L0 / 2;

[0041] Miller projection constant, mill = 2.3;

[0042] Convert longitude from degrees to radians: x = JD * π / 180;

[0043] Convert latitude from degrees to radians: y = WD * π / 180;

[0044] The Miller projection transformation is y = 1.25 * log(tan( 0.25 * π + 0.4 * y ) );

[0045] Convert the horizontal axis radians to actual distance x = (Wx / 2) + (Wx / (2 * π)) * x;

[0046] Convert the vertical axis radians to actual distance y = (Hy / 2) - (Hy / (2 * mill)) * y;

[0047] The transformed rectangular coordinates (X, Y) are

[0048] X = x;

[0049] Y = -y; invert the value to adjust the direction;

[0050] China's longitude range is from 73°33′E to 135°05′E, and its latitude range is from 53°33′N to 3°51′N. After conversion to a rectangular coordinate system, it is located in the first quadrant of the rectangular coordinate system.

[0051] S3): Based on the changing trend of track survey data in the station schematic diagram, determine the orientation of the track in the actual latitude and longitude map;

[0052] like Figure 3 As shown in the station layout diagram, following the convention of "north at the top, south at the bottom, west on the left, and east on the right," the horizontal coordinates of two adjacent survey points D1 and D2 are compared. Figure 3 If x1 is less than x2, the trend of the track survey data is consistent with the orientation of the track on the actual latitude and longitude map; if x1 is greater than x2, the trend of the track survey data is inconsistent with the orientation of the track on the actual latitude and longitude map. In this case, the station schematic diagram is created by rotating and adjusting the latitude and longitude of both ends of the track to ensure that the station schematic diagram is drawn according to the agreed direction of "north at the top, south at the bottom, west on the left, and east on the right".

[0053] S4): In a rectangular coordinate system, use a formula to determine whether the locomotive's coordinate point is above or below the track.

[0054] Step S4) involves using a formula to determine whether the locomotive's coordinates are above or below the track, and includes the following steps:

[0055] S41): Take any two points on the track and convert the two points on the track and the locomotive position into coordinates in a rectangular coordinate system;

[0056] S42): In a rectangular coordinate system, a linear function passing through two points is obtained based on the coordinates of two points taken on the track;

[0057] S43): Substitute the rectangular coordinates of the locomotive position into the linear function and determine the relationship between the value of the linear function and zero. If the value of the linear function is equal to zero, the locomotive position is located on the line connecting the two points of the track. If the value of the linear function is greater than zero, the locomotive position is located above the line connecting the two points of the track. If the value of the linear function is less than zero, the locomotive position is located below the line connecting the two points of the track.

[0058] In a rectangular coordinate system, determining whether a point is above or below a line can be done using mathematical inequalities, such as... Figure 4 As shown,

[0059] Conditions: Line L1: Ax + By + C = 0 (A > 0), point P (x0, y0)

[0060] Then the positional relationship between point P and line L1 in the rectangular coordinate system is as follows:

[0061] When Ax0 + By0 + C = 0, point P lies on line L1.

[0062] When Ax0 + By0 + C > 0, point P is above line L1;

[0063] When Ax0 + By0 + C < 0, point P is below line L1.

[0064] S5): Based on the locomotive coordinates, locomotive head orientation, track orientation, and antenna configuration parameters, the vertical distance of each track in the station map is adjusted by addition or subtraction.

[0065] The method for adding or subtracting compensation for the vertical distance of each track in step S5) includes the following steps;

[0066] S51): Set the locomotive coordinates as P0 (x0, y0), the left end point coordinates of the track as D1 (x1, y1), the right end point coordinates as D2 (x2, y2), the line connecting the left end point coordinates of the track as D1 and the right end point coordinates of the track as line, and the perpendicular distance from the locomotive coordinate P to line as h1.

[0067] S52): Determine if x1 is greater than x2. If it is, the track needs to be reversed, and the value of the vertical distance h1 is -h1.

[0068] S53): Determine whether the locomotive coordinate P0 is below the straight line. If it is below the straight line, the value of the perpendicular distance h1 is -h1.

[0069] S54): Determine whether locomotive head I is to the right of locomotive head II. If it is, the value of the vertical distance h1 is h1+H. If it is not, the value of the vertical distance h1 is h1-H. Where H is the longitudinal distance of the locomotive antenna from the center point of locomotive head I.

[0070] S55): Obtain the absolute value of the perpendicular distance h1 in step S54) to get the compensated perpendicular distance H1=abs(h1);

[0071] S6): Compare the compensated vertical distances of each track, obtain the minimum value of the compensated vertical distance, and calculate the track position of the train head based on the track corresponding to the track with the minimum compensated vertical distance value.

[0072] The method for calculating the position of the locomotive in the track includes the following steps:

[0073] S61): Set the track corresponding to the minimum vertical distance value after compensation as G, that is, track G is the track number where the locomotive is located. Calculate the distance between the locomotive antenna point P and the two ends D1 and D2 of track G based on the latitude and longitude of the locomotive antenna point P and track G.

[0074] S62): Subtract the lateral distance from the distance between the locomotive antenna point P and the two ends of track G to obtain the distance between the locomotive I end head and the two ends of track G, that is, the position of the locomotive head on the track.

[0075] This invention discloses a method for correcting locomotive positioning when the positioning antenna is installed at an offset. When the locomotive positioning antenna is installed at an offset, the locomotive positioning is corrected, which can effectively eliminate the influence of the antenna installation position and improve the accuracy of the locomotive's real-time positioning.

[0076] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A method for correcting a parking space when a positioning antenna installation offset is applied, characterized in that, The method comprises the following steps: S1), measuring the distance between the antenna position on the locomotive and the center point of the I-end head of the locomotive, wherein the distance comprises a longitudinal distance and a transverse distance, and the longitudinal distance and the transverse distance are set as configuration parameters; S2), converting the Beidou coordinate value into a coordinate value in a rectangular coordinate system by using the Miller projection method; S3), judging the orientation of the track in the real latitude-longitude map according to the variation trend of the track surveying data in the station diagram; S4), judging whether the locomotive coordinate point is above or below the track in the rectangular coordinate system by using a formula; S5), adding or subtracting the vertical distance of each track in the station diagram according to the above-or-below information of the locomotive coordinate point, the orientation of the I-end head of the locomotive, the orientation of the track and the antenna configuration parameter information; S6), comparing the compensated vertical distances of each track, obtaining the minimum value of the compensated vertical distance, and calculating the position of the head track according to the track corresponding to the minimum value of the compensated vertical distance. The method for judging whether the locomotive coordinate point is above or below the track in the rectangular coordinate system in step S4) comprises the following steps: S41), converting the two points on the track and the locomotive position into coordinate values in a rectangular coordinate system; S42), obtaining a linear function passing through the two points on the track according to the coordinates of the two points in the rectangular coordinate system; S43), substituting the rectangular coordinates of the locomotive position into the linear function, and judging the size relationship between the value of the linear function and zero, wherein if the value of the linear function is equal to zero, the locomotive position is located on the line connecting the two points on the track, if the value of the linear function is greater than zero, the locomotive position is located above the line connecting the two points on the track, and if the value of the linear function is less than zero, the locomotive position is located below the line connecting the two points on the track. The method for adding or subtracting the vertical distance of each track in step S5) comprises the following steps: S51), setting the locomotive coordinate as P0(x0, y0), the left end point coordinate of the track as D1(x1, y1), the right end point coordinate of the track as D2(x2, y2), the line connecting the left end point coordinate D1 and the right end point coordinate D2 as line, and the vertical distance of the locomotive coordinate P to the line as h1; S52), judging whether x1 is greater than x2, wherein if yes, the track needs to be flipped, and the value of the vertical distance h1 is -h1; S53), judging whether the locomotive coordinate P0 is below the line line, wherein if yes, the value of the vertical distance h1 is -h1; S54), judging whether the I-end head of the locomotive is on the right side of the II-end head of the locomotive, wherein if yes, the value of the vertical distance h1 is h1+H, and if not, the value of the vertical distance h1 is h1-H; wherein H is the longitudinal distance between the antenna and the center point of the I-end head of the locomotive; S55), obtaining the absolute value of the vertical distance h1 in step S54), and obtaining the compensated vertical distance H1=abs(h1). The method for calculating the position of the head track comprises the following steps: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The method for correcting a parking space when positioning an antenna installation offset according to claim 1, characterized in that: ​ S61): Set the track G corresponding to the minimum value of the compensated vertical distance, that is, the track G is the track number where the vehicle head is located, and calculate the distance between the locomotive antenna point P and the two endpoints D1 and D2 on the track G according to the corresponding latitude and longitude of the two endpoints D1 and D2 on the track G. S62): The distance between the locomotive antenna point P and the two endpoints of the track G is respectively subtracted by the transverse distance, and the distance between the I end of the vehicle and the two endpoints of the track G is obtained, that is, the position of the vehicle head on the track is obtained.

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