CN106871805A - vehicle-mounted rail gauge measuring system and measuring method - Google Patents

Abstract

The invention discloses a kind of vehicle-mounted rail gauge measuring system and measuring method, it is related to the measuring equipment technical field to be characterized using optical means.Methods described obtains locomotive relative to left and right Rail Lateral Displacement variable quantity respectively using two groups of lasing light emitters and camera combination, using the change of laterally movable amount between the Rail Lateral Displacement variable quantity difference reflection wheel track of left and right, so as to realize the indirect measurement of track gauge.The hardware configuration that the gauge detection method is used is simple, and data amount of calculation is small, and certainty of measurement is higher, is capable of achieving the non-contact type dynamic measurement of gauge parameter.

Description

Vehicle-mounted rail gauge measuring system and measuring method

technical field

The invention relates to the technical field of measuring equipment characterized by adopting an optical method, in particular to a vehicle-mounted rail gauge measuring system and a measuring method.

Background technique

Under the influence of natural factors and repeated train loads, the track is not only prone to elastic deformation, but also often undergoes permanent deformation, resulting in track irregularities. Track irregularity can cause various vibrations of the train and change the force of the wheel and rail. It is the controlling factor affecting the safety and stability of the train running on the track, and it is an important reason for the damage and failure of the track structural components. With the improvement of high-speed railway operation speed and the expansion of operation scale, it has become an important basic work in rail transportation to strengthen track dynamic detection, timely grasp track status information, correctly guide line maintenance and repair, and ensure rail transportation safety. . Track gauge, as one of the most basic track geometric parameters, has always been an important content of track detection.

The key to track gauge detection is how to quickly and correctly select gauge feature points to calculate gauge value accurately. Since it is difficult to select the gauge measurement points at both ends of the track, most of the current gauge detection methods use the principle of laser triangulation. First, the working edge contours of the single-end track are collected separately, and the image of the working edge contour of the track is realized by calibrating the coordinates of the left and right track sensors and the reference coordinates. Fusion, finally determine the track gauge measurement point and realize the track gauge calculation. This type of method is relatively complicated to calculate at first. Every time the gauge calculation is completed, it is necessary to calibrate the sensors at both ends of the track and the spatial coordinates, the extraction of the laser contour curve, the smoothing filter, the arc matching of the rail head, and the extraction of the gauge calculation points. The transformation and image processing process requires a large amount of calculation. At the same time, in the process of dynamic detection, the aggravation of vibration noise and the change of noise types make the calibration of the two sensor coordinates and space coordinates and the robustness of the positioning algorithm of the center of the laser light band need to be verified.

Contents of the invention

The technical problem to be solved by the present invention is to provide a vehicle-mounted rail gauge measurement system and measurement method. The method converts the measurement of the lateral movement of the gauge feature points on both sides into the vertical displacement of the center point of the laser spot on the rail waist through geometric transformation. The measurement of the gauge improves the resolution of the lateral movement of the gauge feature points, and at the same time reduces the interference of vibration on the wheel-rail relative displacement detection of the gauge feature points.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a vehicle-mounted rail gauge measurement system, which is characterized in that it includes first to second cameras, first to second laser sources, first to second inverted T-shaped fixed frame and computer, the first camera and the first laser source are fixed on the locomotive bogie through the first inverted T-shaped fixed frame, and the first camera is used to capture side image information of the left rail at a certain depression angle, The second camera and the second laser source are fixed on the locomotive bogie through a second inverted T-shaped mount, and the second camera is used to capture side image information of the right rail at a certain depression angle; the first to second cameras are respectively Electrically connected with the computer, the computer is used to extract the vertical position information of the center point of the laser spot according to the images collected by the first camera and the second camera, and compare it with the position of the center point of the laser spot at the initial moment, and calculate the two moments respectively The vertical movement distance of the center point of the laser spot on the left and right sides, according to the geometric relationship between the vertical movement distance of the center point of the laser spot and the relative lateral movement of the wheel and rail, the relative lateral movement distance of the wheel and rail is obtained, that is, the horizontal distance of the calculation point of the working side gauge of the wheel and rail The moving distance is obtained from the difference of the relative lateral movement of the wheels and rails on both sides to obtain the gauge change, thereby obtaining the track gauge. The measured gauge is adjusted by the inertial reference measurement unit to obtain the distance perpendicular to the laying direction of the track. dynamic gauge.

A further technical solution is: the first to second inverted T-shaped fixing brackets include a vertical rod and a horizontal rod, the upper end of the vertical rod is fixedly connected to the bogie, and the lower end of the vertical rod is connected to the horizontal rod Fixedly connected, the vertical rod is perpendicular to the horizontal plane, the horizontal rod is parallel to the steel rail, and the camera and laser source are fixed on the horizontal rod.

A further technical solution is: the planes where the lenses of the first to second cameras and the axes of the emitting heads of the first to second laser sources are located are perpendicular to the direction of the rail, and the focal points of the two laser sources are perpendicular to the rail. heading in the same plane.

A further technical solution is: the image information collected by the first camera and the second camera includes the bottom line of the outer surface of the rail head and the laser spot.

A further technical solution is: a synchronous image acquisition card is installed in the computer, and the images captured by the first camera and the second camera are synchronously transmitted to the computer through the synchronous acquisition card for image processing.

The invention also discloses a method for measuring rail gauge, which is characterized in that the method comprises the following steps:

Fix the first camera and the first laser source on the left side of the locomotive bogie through the first inverted T-shaped mount, and fix the second camera and the second laser source on the right side of the locomotive bogie through the second inverted T-shaped mount. On the side, the camera is used to photograph the corresponding laser spot formed by the laser source on the side of the rail and the bottom line position image on the outer side of the rail head. The direction remains vertical and the focal points of the two said laser sources are in the same plane perpendicular to the direction of the rail;

Calibrate the track gauge corresponding to the center of the laser spot on the left and right sides at the static moment, and obtain the image information collected by the first camera and the second camera synchronously through the computer;

During the movement of the locomotive, the computer analyzes and processes the acquired image information, and obtains the position information of the bottom line of the outer rail head of the left and right rails and the position of the laser spot in real time;

Convert the vertical distance between the outer bottom line of the rail head on the left and right side and the laser spot center point image into the actual space distance, compare the image information at the initial time, and obtain the vertical displacement of the laser spot center point at two moments, from the vertical displacement of the laser spot center point to the lateral distance The geometric relationship of displacement, the lateral displacement change of the rails on both sides relative to the wheel set is obtained, that is, the lateral displacement of the gauge detection point and the wheel set, and the difference between the displacement change of the wheel set relative to the gauge detection points on both sides is the gauge change quantity;

The spatial torsion angle information of the bogie is collected by the inertial reference measurement unit;

According to the reference gauge, gauge variation and bogie spatial torsion angle information, the dynamic gauge perpendicular to the track laying direction is obtained by calculation.

A further technical solution is: during the movement of the locomotive, the computer analyzes and processes the acquired image information, and the method of obtaining the bottom line of the outer rail head of the left and right rails and the position information of the laser spot in real time is as follows:

1) performing grayscale and filtering processing on the images collected by the first camera and the second camera;

2) Extract the bottom line of the outer side of the left and right rail heads through the edge detector, use the maximum brightness pixel in the laser spot as the seed, use the region growing method and the gray-scale center of gravity method to extract the center point of the laser spot, and calculate the center points of the laser spots on both sides to The vertical image distance of the bottom line of the rail head;

3) According to the actual distance represented by the single pixel of the calibrated picture, the image distance from the center point of the laser spot on both sides to the bottom line of the rail head obtained in the above step 2) is converted into a vertical actual distance;

4) Obtain the standard gauge perpendicular to the track laying direction by using the reference track gauge, gauge variation and spatial torsion angle information.

The further technical solution is: take the direction perpendicular to the side of the rail as the X-axis, the direction of the vertical line on the horizontal plane as the direction of the Y-axis, and the direction of the rail as the Z-axis; the lenses of the first camera and the second camera, the first laser source and the second laser The emission head axis of the source is located in the XY plane and is always perpendicular to the Z axis, and the focal points of the two laser sources are in the same XY plane perpendicular to the Z axis; the first inverted T-shaped mount and the second inverted T-shaped mount The vertical bar is parallel to the Y-axis direction, and the horizontal bar is parallel to the Z-axis direction; within the maximum yaw range of the train, adjust the axes of the laser sources on the left and right sides to make the angles between them and the XZ plane θ and β, so that the laser The light spot always moves within the range of the rail waist, and at the same time adjust the angles between the axis of the camera lenses on both sides and the XZ plane to be θ ₁ and β ₁ , so that the laser light spot always moves in the middle of its image; The horizontal tilt angles θ and β and the horizontal tilt angles θ ₁ and β ₁ of the camera are fixed.

The further technical solution is: the edge detector extracts the bottom line of the outer surface of the left and right rail heads, uses the maximum brightness pixel in the laser spot as the seed, uses the region growing method and the gray-scale center of gravity method to extract the center point of the laser spot, and calculates the laser spots on both sides respectively The vertical image distance from the center point to the bottom line of the rail head; assuming that the axis of the camera lens maintains an angle of θ ₁ with the ground, the central axis of the laser transmitter forms an angle θ with the ground, and the horizontal distance between the fixed bracket and the rail at the initial moment is l ₁ , the detection The fixed bracket moves to the right at a distance of l at all times. At this time, the horizontal distance between the fixed bracket and the rail is l ₂ . The horizontal displacement of the center point of the laser spot nn ₁ is the actual relative lateral movement of the wheel and rail. The lateral displacement s on the initial picture is defined as n points to The distance from the bottom of the picture, and the lateral displacement s ₁ on the other picture when the relative displacement of the wheel and rail occurs is the distance from point m to the bottom of the picture, then the measured value of nn ₁ is nn ₁ = n ¹ n ₁ ¹ *k = (s ₁ -s)/sin(θ ₁ -θ)*cosθ*k Among them, n ¹ m ¹ is the distance mapped by the actual length of nm on the picture; n ¹ n ₁ ¹ is the actual length of nn ₁ mapped on the picture The mapped distance; k is the ratio of the actual distance to the distance on the map.

The further technical solution is: according to the gauge, it is defined as the sum of the inner distance between the rails and the wheel-rail free amount, that is, the L _rail =L _{inside +} A1 ₊ A2. During the train operation, the target measurement distance A1 and the target measurement distance A2 are constantly changing Among them, the changes are Δ _A1 and Δ _A2 respectively, and the sum of Δ _A1 and Δ _A2 is the gauge change. Let the right lateral movement of the car body be positive, and the gauge change Δ = Δ _A1 + Δ _A2 . The difference between the relative lateral displacement of the wheel and rail on both sides is obtained by the first camera and the second camera as the gauge variation, and the gauge can be dynamically expressed as L _rail = _Lnei + A ₁ +A ₂ +Δ.

The beneficial effect of adopting the above technical scheme is that the method changes the measurement of the lateral displacement of the gauge feature points on both sides into the measurement of the vertical displacement of the center point of the laser spot on the rail waist through geometric transformation, which improves the measurement of the gauge feature points. The resolution of the traverse value also reduces the interference of vibration on the wheel-rail relative displacement detection of the gauge feature point, and the measurement accuracy is high.

Description of drawings

Fig. 1 is a schematic structural view of the measurement system described in the embodiment of the present invention;

Fig. 2 is the definition figure of gauge in the embodiment of the present invention;

Fig. 3 is a schematic diagram of track gauge detection in an embodiment of the present invention;

Fig. 4 is a schematic diagram of the relative movement of one side wheel and rail in the embodiment of the present invention;

Fig. 5 is the flowchart of laser point image detection in the embodiment of the present invention;

Fig. 6 is a wheel-rail image based on a laser source in an embodiment of the present invention;

Fig. 7 is the image after brightness equalization in Fig. 6;

Fig. 8 is a flow chart of a rough laser spot positioning algorithm in an embodiment of the present invention;

Fig. 9 is the wheel-rail image after the closed operation in Fig. 7;

Fig. 10 is a rough positioning result diagram of the laser point in the embodiment of the present invention;

Fig. 11 is a diagram of the results of precise positioning of laser points in the embodiment of the present invention;

Fig. 12 is a schematic diagram of the relative traverse coordinates of the detection system in the embodiment of the present invention;

Fig. 13 is a data processing interface diagram of the gauge measuring system described in the embodiment of the present invention;

Among them: 1. The first camera 2, the second camera 3, the first laser source 4, the second laser source 5, the first inverted T-shaped fixed frame 6, the second inverted T-shaped fixed frame 7, the locomotive bogie 8, the rail 9. Wheel 10. Laser spot.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following description, a lot of specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do it without departing from the meaning of the present invention. By analogy, the present invention is therefore not limited to the specific examples disclosed below.

Overall, as shown in Figure 1, the present invention discloses a vehicle-mounted rail gauge measurement system, including first to second cameras 1, 2, first to second laser sources 3, 4, first to second inverted T-shaped fixed frame 5, 6 and computer (not shown in the figure). The first camera 1 and the first laser source 3 are fixed on the locomotive bogie 7 through the first inverted T-shaped mount 5, and the first camera 1 is used to shoot the side image information of the left rail 8 at a certain depression angle, so The second camera 2 and the second laser source 4 are fixed on the locomotive bogie 7 by the second inverted T-shaped mount 6, and the second camera 2 is used to take the side image information of the right rail 8 at a certain depression angle; The image information collected by the first camera 1 and the second camera 2 includes the bottom line of the outer surface of the rail head and the laser spot.

Further, the first to second inverted T-shaped fixing brackets 5, 6 include vertical rods and horizontal rods, the upper ends of the vertical rods are fixedly connected to the bogie 7, and the lower ends of the vertical rods are connected to the horizontal rods. The rods are fixedly connected, the vertical rod is perpendicular to the horizontal plane, the horizontal rod is parallel to the steel rail 8, and the camera and laser source are fixed on the horizontal rod. The planes where the lenses of the first to second cameras 1,2 and the axes of the emission heads of the first to second laser sources 3,4 are kept perpendicular to the direction of the steel rail 8, and the focal points of the two laser sources are perpendicular to In the same plane where the steel rail 8 runs.

A synchronous image acquisition card is installed in the computer, and the images collected by the first camera 1 and the second camera 2 are synchronously transmitted to the computer through the synchronous acquisition card for image processing. The computer is used to extract the vertical position information of the center point of the laser spot according to the images collected by the first camera 1 and the second camera 2, and compare it with the position of the center point of the laser spot at the initial moment, and calculate the laser spots on the left and right sides at the two moments respectively The vertical movement distance of the center point, according to the geometric relationship between the vertical movement distance of the center point of the laser spot and the relative lateral movement of the wheel and rail, the relative lateral movement distance of the wheel and rail is obtained, that is, the lateral movement distance of the calculation point of the working side gauge of the wheel and rail. The difference between the relative lateral movement of the side wheels and rails is used to obtain the gauge change, thereby obtaining the track gauge. The inertial reference measurement unit adjusts the measured gauge gauge to obtain the dynamic gauge perpendicular to the track laying direction.

In general, the present invention also discloses a method for measuring rail gauge, said method comprising the following steps:

S101: Fix the first camera 1 and the first laser source 3 on the left side of the locomotive bogie 7 through the first inverted T-shaped fixing frame 5, and fix the second camera 2 and the second laser source 4 through the second inverted T-shaped fixing frame The frame 6 is fixed on the right side of the locomotive bogie 7, and the camera is used to photograph the laser spot formed by the corresponding laser source on the side of the rail 8 and the bottom line position image on the outer side of the rail head. The lens of the camera and the The plane where the axis of the emitter head of the laser source is located is perpendicular to the direction of the rail 8 and the focal points of the two laser sources are in the same plane perpendicular to the direction of the rail 8;

S102: Calibrate the track gauge corresponding to the center of the laser spot on the left and right sides at the static moment, and obtain the image information collected by the first camera 1 and the second camera 2 synchronously through the computer;

S103: During the movement of the locomotive, the computer analyzes and processes the acquired image information, and obtains the position information of the bottom line of the outer rail head of the left and right rails and the position of the laser spot in real time;

S104: Convert the vertical distance between the outer bottom line of the rail head on the left and right sides and the center point image of the laser spot into the actual space distance, compare the image information at the initial time, and obtain the vertical displacement of the center point of the laser spot at two moments, from the vertical displacement of the center point of the laser spot The geometric relationship with the lateral displacement, the lateral displacement change of the rails on both sides relative to the wheel set is obtained, that is, the lateral displacement of the gauge detection point and the wheel set, and the difference between the displacement change of the wheel set relative to the gauge detection points on both sides is the distance change;

S105: Collecting space torsion angle information of the bogie by the inertial reference measurement unit;

S106: Calculate and obtain the dynamic gauge perpendicular to the track laying direction according to the reference gauge, gauge variation and bogie space torsion angle information.

Gauge measurement principle:

The track gauge is defined as the minimum distance between the working edges of two strands of rail within 16 mm below the tread of the rail. At present, the standard gauge for operating railways and urban rail transit in my country is 1435mm. As shown in Figure 2, according to the gauge, it is defined as the sum of the inner distance of the rail and the free distance between the wheel and the rail, that is

L _rail = _inside L + A ₁ + A ₂ (1)

During the running of the train, the target measurement distance A1 and the target measurement distance A2 are constantly changing, and the sum of the changes is the gauge change (assuming that the train body moves to the right to be positive)

Δ = Δ _A1 + Δ _A2 (2)

Therefore, the measurement of the track gauge is transformed into the measurement of the relative lateral movement of the wheels and rails on both sides of the initial gauge.

The detection system uses two sets of laser sources and cameras to measure the relative lateral displacement of the wheel rails on both sides of the track. The structural schematic diagram of the detection system at that time, the lighter curve represents the structural schematic diagram after the car body moves laterally to the right), the plane where the axis of the camera lens and the laser source emitter head is located is always perpendicular to the direction of the rail and the two laser beams The source focus is on the same plane perpendicular to the direction of the rail. In order to accurately collect target images and protect the equipment from damage, it is necessary to maintain a certain height and angle between the equipment and the ground. According to the maximum yaw range of the train, adjust the angles θ and β between the axis of the laser source emitter on both sides and the horizontal plane, so that the laser spot always moves within the range of the rail waist. The center of the image moves. During the running of the train, the horizontal inclination angles θ and β of the laser transmitter and the horizontal inclination angles θ1 and β1 of the camera are fixed. Since the laser source and the camera remain stationary relative to the bogie, when the wheelsets on both sides produce lateral displacements l and L relative to the initial moment , the laser source and the camera will move l and L relative to the track, and the laser spot will move longitudinally on the side of the track (m point→n point) (M point→N point). There is a geometric relationship between the longitudinal movement of the center point of the spot and the lateral movement of the wheel set. Therefore, the change of the center point of the laser spot on the ordinate position on the picture compared with the initial time is selected to calculate the lateral displacement value of the wheels and rails on both sides. Since the focus of the two laser sources is at The same plane perpendicular to the direction of the rail, so the difference of the lateral displacement change on both sides at this moment is the gauge change Δ relative to the initial moment, then the gauge can be dynamically expressed as

L _rail = _inside L + A ₁ +A ₂ +Δ (3)

Image displacement transformation:

In the system, the lateral movement of the locomotive bogie relative to the gauge detection position is consistent with the relative lateral movement of the wheels and rails on both sides, so the vertical movement displacement of the center point of the laser spot on both sides and the wheel and rail of the characteristic point of the gauge in the action side perpendicular to the direction plane of the rail Corresponding relative displacement values. In order to show the horizontal movement of the bogie more intuitively (taking the left device as an example), as shown in Figure 4, the position of the left detection equipment and the actual displacement of the rail at the initial time and the detection time are expressed as the track relative detection equipment in the figure The relative lateral displacement of the bogie and the track at two moments before and after is established through the movement of the center point of the laser spot. Assume that the axis of the camera lens and the ground maintain an angle of θ ₁ , the central axis of the laser emitter forms an angle θ with the ground, the horizontal distance between the fixed bracket and the rail at the initial moment is l ₁ , and the fixed bracket moves to the right for a distance l at the time of detection. At this time, the fixed bracket The horizontal distance from the rail is l ₂ , and the horizontal displacement of the center point of the laser spot nn ₁ is the actual relative lateral movement of the wheel and rail. The lateral displacement s on the initial picture is defined as the distance from point n to the bottom of the picture. When the relative displacement of the wheel and rail occurs, another The lateral displacement s ₁ on a picture is the distance from point m to the bottom of the picture, and the measurement steps of nn ₁ are as follows:

n ¹ m ¹ =(s ₁ -s)/sin(θ ₁ -θ) (4)

n ¹ n ₁ ¹ ＝n ¹ m ¹ *cosθ (5)

nn ₁ =n ¹ n ₁ ¹ *k=(s ₁ -s)/sin(θ ₁ -θ)*cosθ*k (6)

Among them, n ¹ m ¹ is the distance mapped by the actual length of nm on the picture; n ¹ n ₁ ¹ is the distance mapped by the actual length of nn ₁ on the picture; k is the ratio of the actual distance to the distance on the picture.

Then, combined with the right wheel-rail lateral movement data, the displacement variation of the left and right detection equipment relative to the gauge detection point in the same plane perpendicular to the rail direction is calculated, that is, the relative displacement variation of the wheels and rails on both sides, and then the gauge can be calculated.

Image detection:

In order to accurately obtain the position of the center point of the laser spot in the images on both sides, the image is first processed by histogram equalization to increase the contrast between light and dark of the image, and then the rough positioning method of the laser point based on threshold segmentation is used to find the maximum brightness pixel point in the laser spot , using the pixel as a seed, the region growing method is used to search for the pixel position of the entire laser area, and finally the center point of the laser spot is precisely positioned by the gray-scale center of gravity method, and good detection results are obtained. The flow chart of the coordinate detection steps of the center point of the entire laser area is shown in FIG. 5 .

Histogram equalization:

Histogram equalization is mainly to widen the gray levels with a large number of pixels in the image, and compress those gray levels with a small number of pixels, which is conducive to improving the contrast of the original image. After the wheel-rail image is histogram equalized, the result is shown in Figure 6-7. The contrast of the image is significantly enhanced, which is conducive to the subsequent extraction of laser points.

Rough positioning of laser points based on threshold segmentation:

The rough location of the laser point based on threshold segmentation is to roughly mark the position of the laser area in the image, that is, to find a point in the laser area. The process of rough positioning goes through three steps: closing operation, selection of the point with the maximum brightness of the image, neighborhood discrimination, and determination of the laser point with the maximum brightness. The algorithm flow of the rough positioning of the entire laser point is shown in Figure 8.

The closing operation is the result of expansion first and then corrosion. Mathematically, A is recorded as A B by the morphological closing operation of B:

Figure 9 is the result of the closed operation of the wheel-rail image, which improves the brightness value of the pixel value of the entire laser area, removes low-brightness pixels in the area, and is more conducive to finding the location of the laser area later.

The selection of the maximum brightness point of the image and the neighborhood discrimination are first to find the point A in the image that satisfies the laser point RGB model (R>200, B>200, G>200), according to the brightness formula:

T＝R*0.299+G*0.587+B*0.114 (8)

After calculating the brightness T0, search for the next image point B that satisfies the laser point model, calculate the brightness T1, compare the brightness values of T0 and T1 and take the maximum value, and judge whether the number of points in the 5×5 neighborhood satisfy the laser point model If it is greater than 16, if the condition is not met, search for the next laser point, otherwise, update the current laser point position, continue to search for the next laser point position, and repeat until the condition is met, then the search ends. In this way, the location of the maximum brightness point that satisfies the conditions will be found, and the rough positioning result of the laser point is shown in Figure 10. Among them, the coordinates of the detected point are x=1487, y=1068, which is located on the right side of the original white laser area, obviously the detection result is not very accurate.

Precise localization of laser spots based on threshold growth:

The rough positioning of the laser red dot area searches for the pixel with the highest brightness in the entire laser area. But in order to accurately calculate the distance of the lateral offset of the wheel, it is necessary to know the coordinates of the center point in the entire laser field. Since the laser red dot has good directionality, high brightness and highly concentrated energy, the position of the laser spot spot area can be found through the region growing algorithm, and then the coordinates of the center point of the laser spot spot can be obtained through the gray-scale center of gravity method.

The steps of region growing are as follows:

1) Set the maximum brightness point of the laser rough positioning result in the previous section as the seed pixel point (x ₀ , y ₀ );

2) With (x ₀ , y ₀ ) as the center, consider the 8 neighborhood pixels (x, y) of (x ₀ , y ₀ ), if (x, y) satisfies the laser point model, combine (x, y) with (x ₀ ,y ₀ ) are merged in the same area, and (x,y) are pushed onto the stack;

3) Take a pixel from the stack, use it as the seed point (x ₀ , y ₀ ) and return to step 2);

4) When the stack is empty, return to step (1);

5) Repeat steps 1)-4) until every point in the image has an attribution, the growth ends.

The wheel-rail image obtains all the pixels (x _i , y _j ) mapped by the laser point in the image through the region growing algorithm, calculates the brightness T _ij of each pixel point by formula (8), and uses the gray-scale center of gravity method

(wherein, the laser spot area x _i represents the coordinates of the i-th row and x∈(1,m), y _j represents the coordinates of the j-th column and y∈(1,n), m,n∈(spot area), T _ij represents the gray value of the pixel point in row i and column j) to obtain the coordinates of the center point of the laser spot area. The result of the precise positioning of the wheel-rail image is shown in Figure 11. The coordinates of the detected point are x=1456, y=1058, which is located in the center of the white laser area, and the detection result is more accurate.

Experimental data processing and error analysis:

In order to test the performance of the track gauge measurement system based on laser source, this experiment uses a 1:3 locomotive bogie test platform with a length of 10m to simulate vehicle movement for dynamic gauge measurement. As shown in Fig. 12, in the process of bogie simulation movement, the experiment takes the position of the locomotive at the initial moment as the reference position and the gauge of the gauge measurement point as the initial value to carry out quantitative left and right lateral swings for five times to detect gauge changes. Build a Qt detection system software based on OpenCV under the Linux system environment. The image data processing interface is shown in Figure 13. Combine the value manually set by the gauge ruler with the data collected by the gauge detection equipment for data analysis, and change the gauge Multiple replicates were performed. The gauge measurement error in this experiment is the difference between the detection data and the actual data. Since the detection data on both sides is the pixel value on the image, it is necessary to calculate the proportional relationship between the image distance and the actual distance when the image is collected before converting it into the actual distance. After on-site measurement, the actual distance corresponding to 1 pixel of the left image is about 0.092mm, and the corresponding actual distance of 1 pixel of the right image is about 0.093mm. After software testing and analysis, the detection errors of the track gauge measurement system are shown in Table 1.

Table 1 Gauge detection data analysis mm

Detection times set track gauge Measure mean Measurement error Total uncertainty (P=0.95) tolerance scope 10 474 474.40 0.40 0.11 0.29-0.51 10 477 477.43 0.43 0.09 0.34-0.52 10 480 480.51 0.51 0.17 0.34-0.68 10 483 483.47 0.47 0.10 0.37-0.57 10 486 486.38 0.38 0.14 0.24-0.55

From the analysis of the error results, the gauge measurement error range obtained by the measurement system is within ±0.7mm, and the detection error is relatively small. The track gauge can be accurately detected and meets the detection error requirement of ±1mm for high-speed rails. At the same time, under the premise of ensuring the detection accuracy, the simplicity and applicability are improved to a certain extent compared with the prior art.

Claims (10)

1. a kind of vehicle-mounted rail gauge measuring system, it is characterised in that：Including the first to second camera (1,2), the first to the second Lasing light emitter (3,4), the first to the second inverted T shape fixed mount (5,6) and computer, the first camera (1) and first laser source (3) It is fixed on engine truck (7) by the first inverted T shape fixed mount (5), first camera (1) with certain angle of depression for shooting left The side image information of side rail (8), the second camera (2) is with second laser source (4) by the second inverted T shape fixed mount (6) It is fixed on engine truck (7), second camera (2) is believed for shooting the side image on right side rail (8) with certain angle of depression Breath；The first to second camera (1,2) respectively with the calculating mechatronics, computer be used for according to first camera (1) and second Camera (2) collection image zooming-out laser spot center point vertical position information, and with laser spot center point initial time Position contrast, respectively calculate two vertical displacements of moment left and right sides laser spot center point, according to laser light The vertical displacement of spot central point traversing geometrical relationship relative with wheel track draws the relatively transverse displacement of wheel track, i.e. wheel track work Make side gauge and calculate point lateral distance, the difference changed by the relatively traversing amount of both sides wheel track obtains gauge variable quantity, so that Track gauge is tried to achieve, surveyed gauge is adjusted by inertial reference measuring unit, obtained perpendicular to the dynamic of track laying direction State gauge.

2. vehicle-mounted rail gauge measuring system as claimed in claim 1, it is characterised in that：The first to the second inverted T shape is consolidated Determining frame (5,6) includes vertical rod and horizon bar, and the upper end of the vertical rod is fixedly connected with the bogie (7), described vertical The lower end of bar is fixedly connected with the horizon bar, and the vertical rod is perpendicular to horizontal plane, and horizon bar is parallel with rail (8), described Camera and lasing light emitter are fixed on the horizon bar.

3. vehicle-mounted rail gauge measuring system as claimed in claim 1, it is characterised in that：The first to the second camera (1, 2) it is vertical that plane where camera lens and the emitting head axis of the first to second laser source (3,4) and rail (8) move towards holding, and Two focuses of the lasing light emitter are in the same plane moved towards perpendicular to rail (8).

4. vehicle-mounted rail gauge measuring system as claimed in claim 1, it is characterised in that：The first camera (1) and second The image information of camera (2) collection includes rail head of rail lateral surface bottom line and laser facula.

5. vehicle-mounted rail gauge measuring system as claimed in claim 1, it is characterised in that：Synchronization scheme is set in the computer As capture card, the image of the first camera (1) and second camera (2) collection gives meter by the synchronous collecting card synchronous transfer Calculation machine carries out image procossing.

6. a kind of rail gauge measuring method, it is characterised in that methods described comprises the following steps：

First camera (1) and first laser source (3) are fixed on a left side for engine truck (7) by the first inverted T shape fixed mount (5) Side, second camera (2) and second laser source (4) are fixed on the right side of engine truck (7) by the second inverted T shape fixed mount (6) Side, the camera is used to shoot outside the laser facula that the lasing light emitter is formed in rail (8) side accordingly and rail head of rail Plane where the axis of the emitting head of side baseline position image, the camera lens of the camera and the lasing light emitter is walked with rail (8) To keeping vertical and two focuses of the lasing light emitter in the same plane moved towards perpendicular to rail (8)；

Corresponding track gauge where the laser spot center of the Still time left and right sides is demarcated, and the is synchronously obtained by computer One camera (1) and the image information of second camera (2) collection；

During motor sport, computer is analyzed and processes to the image information for obtaining, and left and right sides steel is obtained in real time Rail head bottom line and laser spot position information on the outside of rail；

The outer bottom line of left and right sides rail head of rail is changed into real space distance with the vertical distance of laser spot center dot image, is contrasted Initial time image information, obtains two moment laser spot center point vertical deviations, by laser spot center point vertical deviation with The geometrical relationship of lateral displacement, obtain both sides rail relative to wheel to lateral displacement change i.e. gauge test point with take turns to horizontal stroke To displacement, gauge variable quantity is to the difference relative to both sides gauge test point change in displacement according to wheel；

By inertial reference measuring unit collection bogie space windup-degree information；

According to benchmark rail away from, gauge variable quantity and bogie space windup-degree information, it is calculated perpendicular to track paving The dynamic rail gauge of set direction.

7. rail gauge measuring method as claimed in claim 6, it is characterised in that described during motor sport, meter Calculation machine is analyzed and processes to the image information for obtaining, and rail head bottom line and laser facula position on the outside of left and right sides rail are obtained in real time The method of confidence breath is as follows：

1) gray scale and filtering process are carried out to the image that first camera (1) and second camera (2) are gathered；

2) left and right rail head of rail lateral surface bottom line is extracted by edge detector, brightness maximum pixel point is kind with laser facula Son, laser spot center point is extracted using region growing method and grey scale centre of gravity method, and both sides laser spot center point is calculated respectively To the vertical image distance of rail head of rail bottom line；

3) according to the actual range that represents of picture single pixel demarcated, by above-mentioned steps 2) obtain both sides laser spot center point and arrive The image distance of rail head of rail bottom line is converted to vertical actual range；

4) mark perpendicular to track laying direction is obtained using benchmark track gauge, gauge variable quantity and space windup-degree information Standard gauge away from.

8. rail gauge measuring method as claimed in claim 7, it is characterised in that：It is X-direction to take perpendicular to rail side, Horizontal plane vertical line direction is Y direction, and rail trend is Z-direction；The camera lens of first camera (1) and second camera (2) and the One lasing light emitter (3) is vertical with Z axis holding all the time in X/Y plane with the emitting head axis of second laser source (4), and two are swashed The focus of light source is in the same X/Y plane of vertical Z axle；The first inverted T shape fixed mount (5) and the second inverted T shape fixed mount (6) Vertical rod parallel to Y direction, horizon bar is parallel to Z-direction；Adjustment or so two respectively in the range of train maximum yaw The emitting head axis of the lasing light emitter of side makes it be θ and β with XZ plane included angles, laser facula is moved in the range of the web of the rail all the time, It is θ that both sides camera lens axis is adjusted simultaneously with the angle of XZ planes₁With β₁, laser facula is moved in the middle part of its image all the time； In train travelling process, the level inclination θ and β and the level inclination θ of the camera of the generating laser₁With β₁It is fixed.

9. rail gauge measuring method as claimed in claim 8, it is characterised in that：Edge detector extracts left and right rail head of rail Lateral surface bottom line, brightness maximum pixel point is extracted as seed using region growing method and grey scale centre of gravity method with laser facula Laser spot center point, calculates both sides laser spot center point to the vertical image distance of rail head of rail bottom line respectively；If camera Camera lens axle center keeps θ with ground₁Angle, generating laser axis is into θ angle with ground, initial time fixed support and rail water Flat distance is l₁, detection moment fixed support moves right apart from l, and now fixed support and rail horizontal range are l₂, laser light Spot central point horizontal displacement nn₁It is that actual wheel track is relatively traversing, the lateral displacement s defined in initial picture is n points to picture The distance of bottom, and there is lateral displacement s during relative displacement on another pictures in wheel track₁It is distance of the m points to picture bottom, Then nn₁Measured value is nn₁=n¹n₁ ¹* k=(s₁-s)/sin(θ₁- θ) * cos θ * k wherein, n¹m¹It is the physical length of nm in picture On the distance that is mapped；n¹n₁ ¹It is nn₁The distance that is mapped on picture of physical length；K is actual range and map range The ratio between.

10. rail gauge measuring method as claimed in claim 9, it is characterised in that：According to gauge be defined as in rail away from wheel Rail free amount sum is L_Rail=L_{It is interior}+A₁+A₂In train travelling process, target measurement spacing A1 and target measurement spacing A2 is in not In disconnected change, its variable quantity is respectively Δ_A1And Δ_A2, Δ_A1And Δ_A2Sum is gauge variable quantity, if car body is traversing being to the right Just, gauge variation delta=Δ_A1+Δ_A2, will by first camera and second camera obtain the relatively transverse displacement of both sides wheel track it Difference can dynamically be expressed as L as gauge variable quantity, then gauge_Rail=L_{It is interior}+A₁+A₂+Δ。