A turnout gap baseline calibration method based on line laser assisted positioning

Abstract

The application discloses a kind of based on line laser auxiliary positioning switch machine gap baseline calibration method, comprising: based on laser emission head obtains laser beam, the laser beam includes first laser beam and second laser beam;Based on camera obtains laser beam gap image and shooting direction;The laser beam gap image is handled to obtain baseline position.The present application uses laser beam to carry out auxiliary positioning, without artificial field calibration, greatly improve work efficiency.Moreover, it can be calibrated at any time as needed, greatly increase the measurement accuracy of equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of switch machine gap baseline calibration, and particularly relates to a switch machine gap baseline calibration method based on line laser assisted positioning. BACKGROUND

[0002] The switch machine is one of the important equipment of the railway, and its running state is related to the driving safety of the vehicle. Once a failure cannot be timely eliminated, a very serious accident can be caused. In the monitoring of the running state of the switch machine, the gap is a very important monitoring object. The target position of the gap reflects whether the switch machine is in place, and the size of the gap reflects the close degree of the track. If it is not in place, the wheel hub will press the point rail when the vehicle passes, causing movement, which seriously affects the driving safety of the vehicle. At present, the method commonly used in the industry is to monitor the gap position through remote image, to realize real-time identification and measurement of the image of the gap position, to calculate the gap position and size, and to provide the signal personnel of the electric service section for monitoring and analysis.

[0003] At present, the image-based gap detection needs to calibrate the image detection related parameters before use, so as to realize accurate gap width measurement. The calibration is mainly to obtain the accurate gap measurement baseline and the image pixel width.

[0004] Measurement baseline: for ZYJ7 type, due to the camera installation angle and parallax, the gap gap edge on the photographed image is not the real gap detection edge, as shown in Figure 1 Therefore, for models other than ZYJ7, manual calibration is needed to obtain the accurate position of the drop column.

[0005] Pixel width: due to the deviation of the installation position of the camera of each switch machine, even if the calibration is performed before leaving the factory, calibration according to the actual installation position is still needed in actual use.

[0006] At present, there are two ways for the calibration of the gap image parameters: the gap reference calibration method using a scale and the gap reference calibration method without using a scale. No matter which way is used, the field personnel need to adjust the gap to a certain position, measure the current gap width through the scale, and transmit the current gap picture to the host computer. The operator of the host computer manually calibrates the gap image according to the photographed gap picture and the actual gap width, as shown in Figure 2 The calibration involves site application, cooperation of the construction party, cover opening operation, host computer cooperation, and has high requirements on the operator and the field conditions. It is a very time-consuming and labor-consuming work in the project. In addition, the quality of the calibration directly affects the accuracy of the gap detection. Therefore, improving the calibration efficiency or simplifying the calibration process has great practical application value for the image-based gap monitoring application. SUMMARY

[0007] To solve the prior art problems, the application provides a turnout gap baseline calibration method based on line laser auxiliary positioning. The application comprises a camera with a line laser emitter head and a bracket. The camera emits red line laser beams through the laser emitter head. The laser beams reflect on the turnout rod plane and the post plane to form a line beam. The baseline position of the gap measurement can be obtained according to the position relationship between the line beams. The laser emitter head can be controlled to be turned on or off by the main control.

[0008] To achieve the above technical purposes, the application provides the following technical scheme: a turnout gap baseline calibration method based on line laser auxiliary positioning, comprising:

[0009] obtaining a laser line beam based on a laser emitter head, wherein the laser line beam comprises a first laser line beam and a second laser line beam;

[0010] obtaining a laser line beam gap image and a shooting direction based on a camera;

[0011] processing the laser line beam gap image to obtain a baseline position.

[0012] Preferably, the process of obtaining a laser line beam based on a laser emitter head comprises:

[0013] the laser emitter head emits a line laser beam;

[0014] based on the line laser beam, a first laser line beam is formed on the surface of a rod, and a second laser line beam is formed on the side of a post, wherein the rod and the post are perpendicular to each other.

[0015] Preferably, the process of processing the laser line beam gap image to obtain a baseline position comprises:

[0016] preprocessing the laser line beam gap image to obtain a pretreatment image;

[0017] extracting a plurality of laser line beams based on the pretreatment image;

[0018] obtaining a first line beam and a second line beam based on the plurality of laser line beams;

[0019] obtaining an intersection point based on the baseline and the detection line;

[0020] obtaining a baseline position based on the intersection point and the shooting direction.

[0021] Preferably, the process of preprocessing the laser line beam gap image to obtain a pretreatment image comprises:

[0022] reading the laser line bundle notch image to obtain a laser line bundle notch image in an RGB color space;

[0023] converting the laser line bundle notch image in the RGB color space into a laser line bundle notch image in an HSV space;

[0024] extracting a red laser line bundle based on the laser line bundle notch image in the HSV space, and obtaining a pretreatment image through grayscale processing, binaryzation processing, morphological processing and contour thinning.

[0025] Preferably, the step of extracting the laser line bundle comprises:

[0026] obtaining a set of candidate laser line bundles by using a probabilistic Hough line detection method based on the pretreatment image;

[0027] performing effective checking on the set of candidate laser line bundles based on the switch mechanism and the shooting direction to obtain the reference line and the detection line.

[0028] Preferably, the conditions that the effective checking on the set of candidate laser line bundles to obtain the reference line and the detection line satisfy comprise:

[0029] when the shooting direction is a horizontal direction, the end point coordinate x of a first laser line bundle is less than the start point coordinate y of a second laser line bundle;

[0030] when the shooting direction is a vertical direction, the end point coordinate y of a first laser line bundle is less than the start point coordinate y of a second laser line bundle;

[0031] Preferably, the baseline position is obtained based on the intersection point and the shooting direction, wherein the baseline position comprises:

[0032] when the shooting direction is a horizontal direction, the baseline position is a straight line passing through the intersection point and being perpendicular to the horizontal direction;

[0033] when the shooting direction is a vertical direction, the baseline position is a straight line passing through the intersection point and being perpendicular to the vertical direction.

[0034] The present application has the following technical effects:

[0035] The present application uses laser line bundle for auxiliary positioning, without the need for manual field calibration, greatly improving the work efficiency. Moreover, the present application can be calibrated at any time as needed without affecting the normal working condition of the switch, greatly increasing the measurement accuracy of the equipment and the timeliness of the equipment operation and maintenance.

[0036] The present application installs a laser emitting head at the parallel position of the camera, which can be integrated with the light supplement lamp, and the structure is simple and easy to implement, so that the notch detection device is constructed at low cost, and the precision of notch detection is effectively improved.

[0037] The present application can adjust the direction of linear laser by rotating the laser head, form a laser beam with the best angle in the device, and calibrate the device, effectively solving the technical defects of image shooting error. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0039] Figure 1 A measuring baseline diagram in the background art of the present application;

[0040] Figure 2 A current gap width diagram measured by a scale in the background art of the present application;

[0041] Figure 3 A top view of the camera in the embodiment of the present application;

[0042] Figure 4 A camera with a laser emitting head and a support structure diagram in the embodiment of the present application;

[0043] Figure 5 A camera with a laser emitting head and a support position diagram in the embodiment of the present application;

[0044] Figure 6 An image preprocessing flowchart in the embodiment of the present application;

[0045] Figure 7 An algorithm flowchart for extracting a laser beam in the embodiment of the present application. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0047] Embodiment one

[0048] The present embodiment discloses a switch machine gap baseline calibration method based on linear laser auxiliary positioning. As shown in Figure 3The structure relationship in the switch machine shows that the rod and the inspection column are perpendicular to each other. The laser head emits a laser line, which forms two laser beam lines on the surface of the rod and the vertical surface of the inspection column. The intersection of the extensions of the two beam lines represents the position where the light plane intersects the surface of the rod and the vertical surface of the inspection column. The intersection point is also located on the intersection line of the surface of the rod and the vertical surface of the inspection column, which is the reference line position required for gap detection. Therefore, the position (coordinates) of the reference line can be calculated by extracting the laser beam lines on the surface of the rod and the inspection column using image algorithms and calculating the intersection of the extensions of the two beam lines.

[0049] 1. Camera and bracket with laser emitting head

[0050] As shown in the figure, the camera and the laser emitting head are installed on the bracket inside the switch machine, and the distance between them is adjusted by adjusting the angle of the laser line of the laser emitting head. The laser beam lines are formed on the surface of the rod and the vertical surface of the inspection column, and are within the shooting range of the camera. Figures 4-5

[0051] 2. Shooting laser picture

[0052] According to the shooting angle of the bracket and the adjustment of the emission angle of the laser line, the laser beam lines are just irradiated on the surface of the rod and the inspection column, and form a certain angle. Taking the horizontal direction as an example, the gap picture is shot.

[0053] 3. Extracting laser beam lines

[0054] 3.1 Image preprocessing

[0055] As shown in the figure, it is the process of image preprocessing. Figure 6

[0056] 3.2 Extracting laser beam lines

[0057] The main steps include:

[0058] 1) Obtain the candidate laser beam line (segment) set by the probability Hough straight line detection method.

[0059] 2) Use the structural characteristics of the switch machine to check the effectiveness of the laser beam lines.

[0060] The two laser beam lines are located in two parts of the image, which are just divided by the gap. According to the orientation (horizontal or vertical) of the gap shooting image, the following conditions need to be met:

[0061] Condition 1:

[0062] If horizontal: the x-coordinate of the end point of laser beam line 1 should be less than the y-coordinate of the start point of laser beam line 2.

[0063] ​​If vertical direction: the end point y coordinate of laser beam 1 should be less than the start point coordinate y of laser beam 2.

[0064] Condition 2:

[0065] Considering the actual detection precision requirement of engineering, it should also satisfy that the angle between the two line beams is greater than the set threshold value delta (the default setting is 5°).

[0066] The specific algorithm is shown in Figure 7 .

[0067] 3.3 Calculation of the intersection point of the laser line beams

[0068] The intersection point CrossPoint (x, y) can be obtained by calculating the intersection point of the two straight lines using the line beam 1 and line beam 2 obtained in the above steps.

[0069] This embodiment takes the horizontal direction as an example.

[0070] 3.4 Obtaining the baseline position

[0071] According to the direction of the notch shooting image and the intersection point CrossPoint, the baseline position can be obtained.

[0072] In the horizontal direction, the baseline position x = CrossPoint.x

[0073] In the vertical direction, the baseline position y = CrossPoint.y

[0074] This embodiment takes the horizontal direction as an example.

[0075] As a preferred embodiment of this embodiment, the notch image shooting device with line laser auxiliary positioning in this embodiment has the following characteristics:

[0076] a) The line laser emitting head can adjust the direction of the line beam by rotating;

[0077] b) The device is provided with a switch control, which can control the opening and closing of the line laser;

[0078] c) The line laser can use other colors, and the processing method is similar.

[0079] The main content of the present application is to utilize the structural characteristics inside the switch machine, adopt two intersecting lines represented by the rod and the inspection column by using line laser irradiation, obtain the intersection position of the rod plane and the inspection column plane, that is, the inspection reference, by calculating the intersection point of the intersecting lines.

[0080] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for calibrating a turnout gap baseline based on a line laser assisted positioning, characterized in that, The method comprises the following steps: obtaining a laser beam based on a laser emitting head, wherein the laser beam comprises a first laser beam and a second laser beam; obtaining a laser beam gap image and a shooting direction based on the laser beam by using a camera; processing the laser beam gap image to obtain a baseline position; the process of processing the laser beam gap image to obtain the baseline position comprises the following steps: preprocessing the laser beam gap image to obtain a preprocessed image; extracting a plurality of laser beams based on the preprocessed image to obtain a first extracted laser beam and a second extracted laser beam; obtaining an intersection point based on the first extracted laser beam and the second extracted laser beam; and obtaining the baseline position based on the intersection point and the shooting direction; the process of obtaining the preprocessed image comprises the following steps: reading the laser beam gap image to obtain a laser beam gap image in an RGB color space; converting the laser beam gap image in the RGB color space into a laser beam gap image in an HSV space; extracting a red laser beam based on the laser beam gap image in the HSV space, and obtaining the preprocessed image through grayscale processing, binaryzation processing, morphological processing and contour thinning; the step of extracting the laser beam comprises the following steps: obtaining a set of candidate laser beams by using a probabilistic Hough line detection method based on the preprocessed image; and performing effective checking on the set of candidate laser beams based on a switch mechanism and the shooting direction to obtain the first extracted laser beam and the second extracted laser beam; the conditions met by the first extracted laser beam and the second extracted laser beam comprise: when the shooting direction is a horizontal direction, the terminal coordinate x of the first extracted laser beam is less than the starting coordinate x of the second extracted laser beam; and when the shooting direction is a vertical direction, the terminal coordinate y of the first extracted laser beam is less than the starting coordinate y of the second extracted laser beam; the baseline position comprises: when the shooting direction is a horizontal direction, the baseline position is a straight line passing through the intersection point and being perpendicular to the horizontal direction; and when the shooting direction is a vertical direction, the baseline position is a straight line passing through the intersection point and being perpendicular to the vertical direction.

2. The method of claim 1, wherein the method further comprises: the process of obtaining the laser beam based on the laser emitting head comprises the following steps: the laser emitting head emits a one-line laser; based on the one-line laser, a first laser beam is formed on the surface of a representation rod, and a second laser beam is formed on the side surface of an inspection column, wherein the representation rod and the inspection column are perpendicular to each other.

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