A visual-based rail turnout milling and grinding method

Abstract

The application provides a kind of steel rail turnout milling and grinding processing method based on vision, belongs to the field of track traffic maintenance intelligent equipment, comprising: obtaining the three-dimensional data of steel rail turnout;The three-dimensional data is fitted to generate two-dimensional turnout track diagram;The distance between the upper rail of frog heart and the lower rail of frog heart is l 1 Place vertical first boundary line, the distance between the connecting point of upper side switch rail and upper side wing rail l 2 Place vertical second boundary line, the distance between upper side general rail and upper side switch rail l 2 Place vertical third boundary line, according to the first to the sixth curve and the first to the third boundary line, determine the processable area and non-processable area of steel rail turnout;Control the milling and grinding car to process the processable area.This application can effectively improve the processing efficiency and processing precision, completely repair the disease site, and avoid damage to the steel rail turnout.

Description

Technical Field

[0001] This invention belongs to the field of intelligent equipment for rail transit maintenance, and specifically relates to a vision-based milling and grinding method for steel rail turnouts. Background Technology

[0002] As the "joints" of railway lines, rail turnouts directly affect the smoothness and safety of train operation. After entering service, initial defects such as deformation and microcracks gradually form on the surface of rail turnouts. If not addressed promptly, these defects will worsen into serious flaws such as "edge thickening" and peeling, causing severe vibrations in the train and track system, accelerating component damage, and significantly reducing operational safety and comfort. Therefore, real-time and scientific maintenance of rail turnouts is crucial.

[0003] Due to the complex structure of steel rail turnouts and the concentrated stress on the rail surface, the existing technology of using railcars for grinding has drawbacks such as many blind spots in the grinding operation, low efficiency, poor precision, and difficulty in completely repairing defects. Summary of the Invention

[0004] The purpose of this invention is to propose a vision-based milling method for steel rail turnouts, which can effectively improve processing efficiency and accuracy, thoroughly repair damaged parts, and avoid damage to the steel rail turnouts.

[0005] This invention is achieved through the following technical solution:

[0006] A vision-based milling method for steel rail turnouts, the steel rail turnout including an upper conventional rail, a lower conventional rail, an upper switch rail, a lower switch rail, an upper wing rail, a lower wing rail, an upper rail of the frog, and a lower rail of the frog, the upper switch rail being connected to the upper wing rail, and the lower switch rail being connected to the lower wing rail, includes the following steps:

[0007] Step S1: Use a 3D line laser scanner to scan the rail turnout to generate three-dimensional data of the rail turnout;

[0008] Step S2: Fit the three-dimensional data to generate a two-dimensional turnout trajectory diagram. The two-dimensional turnout trajectory diagram includes a first curve corresponding to the upper ordinary rail, a second curve corresponding to the lower switch rail and the upper rail of the frog, a third curve corresponding to the upper switch rail and the lower rail of the frog, a fourth curve corresponding to the lower ordinary rail, a fifth curve corresponding to the upper wing rail, and a sixth curve corresponding to the lower wing rail.

[0009] Step S3: The distance between the upper side rail and the lower side rail of the frog is... l A vertical first boundary line is set at one point, at the distance from the connection point between the upper switch rail and the upper wing rail. l Two vertical second boundary lines are set at the locations, with the distance between the upper ordinary rail and the upper switch rail being [missing information]. lThree vertical third boundary lines are set at each location. Based on the first to sixth curves and the first to third boundary lines, the workable and non-workable areas of the rail turnout are determined.

[0010] Step S4: Control the milling machine to perform milling on the machinable area.

[0011] Furthermore, in step S1, the starting point of the scan is set to be a distance from the starting point of the lower side rail. l At a distance of meters, draw a straight line perpendicular to the lower ordinary track from the starting point of the scan, and establish an XOY coordinate system with the foot of the perpendicular as the origin. The X direction of the coordinate system is the direction of movement along the lower ordinary track, and the Y direction is the direction pointing to the upper ordinary track.

[0012] Furthermore, in step S1, l ≥1m.

[0013] Furthermore, in step S2, the weighted least squares method is used to fit the three-dimensional data to obtain the first curve. f 1( x ), second curve f 2( x ), third curve f 3( x ), fourth curve f 4( x Fifth Curve f 5( x ), and the sixth curve f 6( x During the fitting process, different weights are assigned to each data point.

[0014] Furthermore, in step S3, according to the formula f 2( x A )- f 3( x A )= l 1. Calculate the x-coordinate at the first boundary line. x A When the switch is in the first state, according to the formula Calculate the x-coordinate of the connection point between the upper switch rail and the upper wing rail. When the switch is in the second state, according to the formula Calculate the x-coordinate of the connection point between the lower switch rail and the lower wing rail. According to the formula Calculate the x-coordinate at the second boundary line. x B When the switch is in the first state, according to the formula f 1( x C )-f 3( x C )= l 3. Calculate the x-coordinate at the third boundary line. x C According to the formula Calculate the x-coordinate of the starting point of the switch rail When the switch is in the second state, according to the formula f 2( x C )- f 4( x C )= l 3. Calculate the x-coordinate at the third boundary line. x C According to the formula Calculate the x-coordinate of the starting point of the switch rail x-axis x In scope and The area inside is the non-processable area, and the others are the processable areas. The switch is in the first state when the upper switch rail, upper wing rail, frog center lower rail, and lower ordinary rail are in use. The switch is in the second state when the lower switch rail, lower wing rail, frog center upper rail, and upper ordinary rail are in use.

[0015] Furthermore, in step S3, when the switch is in the first state, the unprocessable area refers to the horizontal coordinate. x In scope and The unprocessable areas of the upper switch rail, upper wing rail, upper frog rail, and lower frog rail inside the switch, when the switch is in the second state, are indicated by the horizontal axis. x In scope and The inner side switch rail, lower side wing rail, upper side rail of the frog, and lower side rail of the frog.

[0016] Furthermore, in step S3, l 1≥35mm, l 2≥200mm, l 3≥35mm.

[0017] Furthermore, in step S4, sloping processing areas are set at both ends of the processing area to achieve a gradual transition of processing depth to the processing area.

[0018] Furthermore, in step S4, the starting coordinates of the ramp entry and the starting coordinates of the ramp exit for each processing area are determined based on the length of the processing area and the milling machine parameters. The CNC system of the milling machine reads all the starting coordinates in advance and performs ramp processing at the corresponding positions.

[0019] The present invention has the following beneficial effects:

[0020] 1. This invention first uses a 3D laser scanner to scan the rail turnout to generate three-dimensional data of the rail turnout. Then, the three-dimensional data is fitted to generate a two-dimensional turnout trajectory diagram. The two-dimensional turnout trajectory diagram includes a first curve corresponding to the upper conventional rail, a second curve corresponding to the lower switch rail and the upper rail of the frog, a third curve corresponding to the upper switch rail and the lower rail of the frog, a fourth curve corresponding to the lower conventional rail, a fifth curve corresponding to the upper wing rail, and a sixth curve corresponding to the lower wing rail. Then, the distance between the upper rail of the frog and the lower rail of the frog is... l A vertical first boundary line is set at one point, at the distance from the connection point between the upper switch rail and the upper wing rail. l Two vertical second boundary lines are set at the locations, with the distance between the upper ordinary rail and the upper switch rail being [missing information]. l Three vertical third boundaries are set. Based on the first to sixth curves and the first to third boundaries, the machinable and non-machinable areas of the rail turnout are determined. Finally, the milling machine is controlled to mill the machinable areas. This can ensure rapid milling of the machinable areas without human intervention, eliminate blind spots in the processing, effectively improve processing efficiency and accuracy, thoroughly repair damaged parts, and avoid problems such as the inability to automatically process the entire turnout or the inability to determine the processing area due to the complex structure of the turnout, which can lead to damage to the turnout rails. Attached Figure Description

[0021] The present invention will now be described in further detail with reference to the accompanying drawings.

[0022] Figure 1 This is a flowchart of the present invention.

[0023] Figure 2 This is a schematic diagram of a steel rail turnout when the switch of the present invention is in the first state.

[0024] Figure 3 This is a schematic diagram of a steel rail turnout when the switch of the present invention is in the second state.

[0025] Figure 4 This is a schematic diagram of the two-dimensional turnout trajectory of the present invention.

[0026] Among them, 1. Upper ordinary rail; 2. Lower ordinary rail; 3. Upper switch rail; 4. Lower switch rail; 5. Upper wing rail; 6. Lower wing rail; 7. Upper rail of the frog; 8. Lower rail of the frog. Detailed Implementation

[0027] like Figures 1 to 4As shown, the steel rail turnout includes an upper conventional rail 1, a lower conventional rail 2, an upper switch rail 3, a lower switch rail 4, an upper wing rail 5, a lower wing rail 6, an upper rail 7 at the frog point, and a lower rail 8 at the frog point. The upper switch rail 3 is connected to the upper wing rail 5, and the lower switch rail 4 is connected to the lower wing rail 6. The milling and grinding method for the steel rail turnout includes the following steps:

[0028] Step S1: Use a 3D line laser scanner to scan the rail turnout to generate three-dimensional data of the rail turnout;

[0029] The 3D line laser scanner is installed on the turnout milling machine, and the scanning starting point is set at a distance of 4 from the lower switch rail. l At a distance of meters, a straight line perpendicular to the lower ordinary rail 2 is drawn from the starting point of the scan. An XOY coordinate system is established with the foot of the perpendicular as the origin. The X direction of the coordinate system is the direction of advancement along the lower ordinary rail 2, and the Y direction is the direction pointing towards the upper ordinary rail 1. The scan area includes the upper switch rail 3, the lower switch rail 4, the upper wing rail 5, the lower wing rail 6, the upper rail of the frog center 7, the lower rail of the frog center 8, and the corresponding portions of the upper ordinary rail 1 and the lower ordinary rail 2. In this embodiment, l= 1m.

[0030] Step S2: Fit the three-dimensional data to generate a two-dimensional turnout trajectory diagram. The two-dimensional turnout trajectory diagram includes a first curve corresponding to the upper ordinary rail 1, a second curve corresponding to the lower switch rail 4 and the upper rail 7 of the frog, a third curve corresponding to the upper switch rail 3 and the lower rail 8 of the frog, a fourth curve corresponding to the lower ordinary rail 2, a fifth curve corresponding to the upper wing rail 5, and a sixth curve corresponding to the lower wing rail 6.

[0031] Specifically, the weighted least squares method is used to fit the three-dimensional data to obtain the first curve. f 1( x ), second curve f 2( x ), third curve f 3( x ), fourth curve f 4( x Fifth Curve f 5( x ), and the sixth curve f 6( x In the fitting process, the fitted function is an exponential function, and each data point is assigned a different weight to control its influence on the fitting result. The weight of each data point is determined according to the existing "method based on measurement error," which is a current technique.

[0032] For example, let a set of data points be... We want to fit a function: , θLet be the parameters to be fitted. For a nonlinear model of an exponential function, it is... θ =( a , b ),Right now In this embodiment of the weighted least squares method, what is minimized is the weighted sum of squared errors. ,in, w i >0 is the first i The weight of each data point is determined by its weight; a larger weight indicates a greater impact of that point on the fitting result.

[0033] Step S3: The distance between the upper side rail 7 and the lower side rail 8 of the frog is... l A vertical first boundary line A is set at a distance of 3 from the upper side switch rail and 5 from the connection point of the upper side wing rail. l Two vertical second boundary lines are set at points B, with the distance between the upper ordinary rail 1 and the upper switch rail 3 being [missing information]. l Three vertical third boundary lines C are set at three locations. Based on the first to sixth curves and the first to third boundary lines, the workable and non-workable areas of the rail turnout are determined.

[0034] Specifically, "the distance between the upper side rail 7 and the lower side rail 8 of the frog" refers to the vertical distance between the lower side of the upper side rail 7 and the upper side of the lower side rail 8 of the frog, and "the distance between the upper ordinary rail 1 and the upper switch rail 3" refers to the vertical distance between the upper side of the upper ordinary rail 1 and the lower side of the upper switch rail 3.

[0035] According to the formula f 2( x A )- f 3( x A )= l 1. Calculate the x-coordinate at the first boundary line. x A When the switch is in the first state, according to the formula Calculate the x-coordinate of the connection point between the upper side rail 3 and the upper side wing rail 5. When the switch is in the second state, according to the formula Calculate the x-coordinate of the connection point between the lower switch rail 4 and the lower wing rail 6. According to the formula Calculate the x-coordinate at the second boundary line. x B When the switch is in the first state, according to the formula f 1( x C )- f 3( x C )= l 3. Calculate the x-coordinate at the third boundary line.x C According to the formula Calculate the x-coordinate of the starting point of the switch rail When the switch is in the second state, according to the formula f 2( x C )- f 4( x C )= l 3. Calculate the x-coordinate at the third boundary line. x C According to the formula Calculate the x-coordinate of the starting point of the switch rail x-axis x In scope and The area inside is the non-processable area, and the others are the processable areas. The switch is in the first state when the upper switch rail 3, upper wing rail 5, frog center lower rail 8, and lower ordinary rail 2 are in use. The switch is in the second state when the lower switch rail 4, lower wing rail 6, frog center upper rail 7, and upper ordinary rail 1 are in use.

[0036] When the switch is in the first state, the unprocessable area refers to the horizontal axis. x In scope and The upper side rail 3, upper side wing rail 5, upper side rail 7 of the frog center, and lower side rail 8 of the frog center, when the switch is in the second state, the unprocessable area refers to the horizontal axis. x In scope and The inner side rail 4, the lower side wing rail 6, the upper side rail of the frog 7, and the lower side rail of the frog 8.

[0037] In this embodiment, l 1=35mm, l 2 = 200mm l 3 = 35mm.

[0038] Step S4: Control the milling machine to perform milling on the machinable area;

[0039] Specifically, due to irregular defects such as uneven wear, corrugation, and welded joints in the rails, direct full-section machining can easily cause rail surface steps, affecting the stability and safety of train operation. Therefore, to ensure a smooth milling transition and the continuity of the rail surface morphology, inclined machining areas are set at both the front and rear ends of the machining zone. This allows for a gradual transition in machining depth, effectively reducing rail surface runout and improving machining quality and rail lifespan. In practice, the starting coordinates of the inclined entry and exit points for each machining zone are determined based on the length of the machining zone and the parameters of the milling machine. The CNC system of the milling machine pre-reads all starting coordinates and performs inclined machining at the corresponding positions.

[0040] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the specification of the present invention should still fall within the scope of the patent of the present invention.

Claims

1. A vision-based rail turnout milling method, the rail turnout comprising an upper main rail, a lower main rail, an upper switch rail, a lower switch rail, an upper wing rail, a lower wing rail, a frog nose upper rail and a frog nose lower rail, the upper switch rail being connected to the upper wing rail, the lower switch rail being connected to the lower wing rail, characterized in that: The method comprises the following steps: S1. Scanning the rail turnout by using a 3D line laser scanner to generate three-dimensional data of the rail turnout; S2. Fitting the three-dimensional data to generate a two-dimensional turnout track diagram, which comprises a first curve corresponding to the upper main rail, a second curve corresponding to the lower switch rail and the upper rail of the frog center, a third curve corresponding to the upper switch rail and the lower rail of the frog center, a fourth curve corresponding to the lower main rail, a fifth curve corresponding to the upper wing rail, and a sixth curve corresponding to the lower wing rail; Step S3, the distance between the upper side rail of the frog heart and the lower side rail of the frog heart is l 1. A vertical first boundary line is arranged at the position, the distance between the upper side rail and the upper side wing rail is l 2. A vertical second boundary line is arranged at the position, the distance between the upper side rail and the upper side wing rail is l 3. A vertical third boundary line is arranged at the position, according to the first to sixth curves and the first to third boundary lines, the machinable area and the non-machinable area of the steel rail turnout are determined. S4. Controlling the milling and grinding vehicle to mill and grind the processable area.

2. A vision-based rail turnout milling method according to claim 1, characterized in that: In the step S1, the start point of the scanning is set to be a distance from the start point of the lower side switch rail l The start point of the scanning is set to be a distance from the start point of the lower side switch rail, and a straight line perpendicular to the lower side common rail is drawn from the start point, and an XOY coordinate system is established with the foot point as the origin. The X direction of the coordinate system is the direction along the lower side common rail, and the Y direction is the direction pointing to the upper side common rail.

3. A vision-based rail turnout milling method according to claim 2, wherein: Said step S1, l ≥ 1 m.

4. A vision-based rail turnout milling method according to claim 2 or 3, characterized in that: In step S2, the three-dimensional data is fitted by using a weighted least square method to obtain a first curve f 1( x ), a second curve f 2( x ), a third curve f 3( x ), a fourth curve f 4( x ), a fifth curve f 5( x ), and a sixth curve f 6( x ). In the fitting process, each data point is given a different weight.

5. A vision-based rail turnout milling method according to claim 4, wherein: In step S3, the horizontal coordinate at the first boundary is calculated according to the formula f 2( x A )- f 3( x A )= l 1 x A , when the switch is in the first state, the horizontal coordinate of the connection point of the upper point rail and the upper wing rail is calculated according to the formula , when the switch is in the second state, the horizontal coordinate of the connection point of the lower point rail and the lower wing rail is calculated according to the formula , the horizontal coordinate at the second boundary is calculated according to the formula x B , when the switch is in the first state, the horizontal coordinate of the connection point of the upper point rail and the upper wing rail is calculated according to the formula f 1( x C )- f 3( x C )= l 3 x C , the horizontal coordinate of the starting point of the point rail is calculated according to the formula , when the switch is in the second state, the horizontal coordinate of the connection point of the lower point rail and the lower wing rail is calculated according to the formula f 2( x C )- f 4( x C )= l 3 x C , the horizontal coordinate of the starting point of the point rail is calculated according to the formula , the area with the horizontal coordinate x in the range and is the non-machinable area, and the other is the machinable area, wherein the switch is in the first state refers to when the upper point rail, the upper wing rail, the lower rail of the frog heart and the lower general rail are used, and the switch is in the second state refers to when the lower point rail, the lower wing rail, the upper rail of the frog heart and the upper general rail are used.​​​​​ 6. A vision-based rail turnout milling method as claimed in claim 5, wherein: In the step S3, when the switch is in the first state, the non-machinable region refers to the horizontal coordinate x In the range And In the upper side of the rail, the upper side of the wing rail, the upper side of the frog heart rail and the lower side of the frog heart rail, when the switch is in the second state, the non-machinable region refers to the horizontal coordinate x In the range And In the lower side of the rail, the lower side of the wing rail, the upper side of the frog heart rail and the lower side of the frog heart rail.

7. A vision-based rail turnout milling method as claimed in claim 6, characterized in that: Said step S3, l 1 ≥ 35 mm, l 2 ≥ 200 mm, l 3 ≥ 35 mm.

8. A vision-based rail turnout milling method according to claim 1 or 2 or 3, characterized in that: In the step S4, a slope processing area is arranged at both ends of the processing area to realize gradual transition of the processing depth to the processing area.

9. A vision-based rail turnout milling method according to claim 8, characterized in that: In the step S4, the start coordinates of the slope cutting-in and the start coordinates of the slope cutting-out of each processing area are determined according to the length of the processing area and the parameters of the milling and grinding vehicle, and the numerical control system of the milling and grinding vehicle reads all the start coordinates in advance and performs slope processing at the corresponding positions.

Images