Visual detection method for boxcar upper door lock pin state

Abstract

The invention discloses a boxcar upper door lock pin state visual detection method, which performs automatic detection based on line laser structured light vision and image detection fusion, is high in detection efficiency and ensures the detection accuracy. A line laser and an area-array camera are installed on one side of a to-be-detected vehicle, a line laser structured light vision sensor is constructed, firstly, the area-array camera is used for shooting clear visible light images on the side face of a compartment in a normal exposure mode, the position of an upper door lock pin is detected and positioned through a deep learning algorithm, then the line laser is controlled to emit high-power line laser, and the line laser is controlled to emit high-power line laser. The exposure time of the area-array camera is adjusted and shortened to enable the area-array camera to only image a laser light strip image, then line structured light three-dimensional reconstruction is only performed on a laser light strip at the position of the upper door lock pin, if the laser light strip at the position is judged to be a straight line, it is judged that the upper door lock pin is not inserted into the lock pin hole, and if the laser light strip is judged not to be a straight line segment, it is judged that the upper door lock pin is inserted into the lock pin hole. And if not, judging that the upper door lock pin is inserted into the lock pin hole.

Description

Technical Field

[0001] The invention relates to the technical field of freight train vehicle detection, and in particular to a method for visually detecting the state of a door lock pin on a boxcar. Background Art

[0002] Boxcars are one of the important types of vehicles for freight trains, and the train inspection workshop of the vehicle depot undertakes the important work of boxcar safety inspection and maintenance. Among them, the upper door lock pin of the boxcar door is an important part of the safety inspection and maintenance of freight cars. When the boxcar door is normally locked, the upper door lock pin should be accurately inserted into the lock pin hole of the upper side beam. However, since the upper door lock pin is located on the upper part of the vehicle, and the upper door lock opening and closing rod of the vehicle middle door is hidden in the vehicle body in some models, it is difficult to observe the state of the upper door lock pin on the ground, and it is difficult to judge whether it is accurately inserted into the lock pin hole of the upper side beam when the door is closed. At present, the detection of the upper door lock pin state relies on manual use of a special tool, that is, a long rod, which goes deep into the gap between the upper door lock pin seat and the upper side beam, and judges whether the upper door lock pin is accurately inserted into the lock pin hole based on whether there is a mechanical collision. This method is inefficient, cumbersome to operate, and prone to false detection; for this reason, it is urgent to develop a reliable detection method. Summary of the invention

[0003] In response to the above problems, the present invention provides a method for visual detection of the door lock pin status of a boxcar, which performs automated detection based on the fusion of line laser structured light vision and image detection, has high detection efficiency, and ensures detection accuracy.

[0004] A method for visually detecting the state of a door lock pin of a boxcar is characterized in that: a line laser and an array camera are installed on one side of a vehicle to be inspected to construct a line laser structured light visual sensor; first, a clear visible light image of the side of the car body is captured by the array camera with normal exposure, and the position of the door lock pin is detected and located by a deep learning algorithm; then, the line laser is controlled to emit a high-power line laser, and the exposure time of the array camera is adjusted and shortened so that only a laser light strip image can be imaged; then, only the laser light strip at the position of the door lock pin is reconstructed in line structured light three-dimensionally; if the laser light strip at the position is judged to be a straight line, it is judged that the door lock pin is not inserted into the lock pin hole; if the laser light strip is judged not to be a straight line segment, it is judged that the door lock pin has been inserted into the lock pin hole.

[0005] It is further characterized by:

[0006] A line laser and an area array camera are pre-installed at a set position, which is the door lock pin status detection station of the boxcar. A vertical pole is installed at a position away from the side of the car body, and a line laser is installed on the vertical pole. The height of the line laser is the height of the door lock pin. The line laser projects a horizontal laser surface onto the car body, which corresponds to the gap between the door lock pin seat and the lock pin hole of the upper side beam. At the same time, an area array camera is installed on the vertical pole corresponding to the bottom of the line laser. The area array camera takes pictures of the side of the car body, and the field of view of the area array camera covers the image at the laser light strip.

[0007] The boxcar drives along the track into the door lock status detection station on the boxcar. The industrial computer obtains the information that the boxcar is in place and triggers the line laser and area array camera to take pictures.

[0008] The industrial computer is also equipped with an image processing server for image acquisition, processing and line structured light stereo vision reconstruction.

[0009] It is further characterized by:

[0010] It includes the following specific steps:

[0011] S1. When the vehicle arrives at the detection position, the area array camera is controlled to take pictures of the side of the vehicle compartment with adaptive exposure to obtain a side picture of the vehicle compartment;

[0012] S2. Process the side image of the carriage, use the deep learning detection and recognition algorithm to detect and identify the approximate position of the upper door lock pin, and draw a detection frame;

[0013] S3, controlling the line laser to project laser light onto the carriage, using the area array camera to take a picture of the laser light strip with a low exposure time, and extracting the center of the light strip of the detection frame obtained in step S2;

[0014] S4, using the line laser structured light vision model to perform 3D reconstruction of the light strip in the detection frame;

[0015] S5. Determine whether the reconstructed laser light bar is a straight line segment. If so, it means that the laser does not hit the upper door lock pin and the upper door lock pin is not inserted into the lock pin hole. If not, it means that the laser is projected onto the upper door lock pin and the upper door lock pin is inserted into the lock pin hole.

[0016] After adopting the present invention, the line laser and the area array camera are used to cooperate to complete the automatic detection of the insertion status of the door lock pin based on vision, providing an automated detection means and no longer relying on manual detection; at the same time, the detection equipment uses two stages of target detection initial positioning and line structured light 3D measurement to complete the detection of the insertion status of the door lock pin. By adjusting the exposure time, the area array camera has the functions of target detection and recognition and image shooting camera at the same time, further reducing the number of sensors used and reducing costs; it performs automated detection based on the fusion of line laser structured light vision and image detection, has high detection efficiency, and ensures detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the installation of the line laser and the area array camera used in the method of the present invention;

[0018] The names corresponding to the serial numbers in the figure are as follows:

[0019] Carriage 1, upper door lock pin 2, upper door lock pin seat 3, upper side beam 4, lower lock pin hole 5;

[0020] Install the line laser 10, the area array camera 20, and the pole 30. DETAILED DESCRIPTION

[0021] A visual detection method for the state of a door lock pin of a boxcar: a line laser and an array camera are installed on one side of a vehicle to be inspected to construct a line laser structured light visual sensor; first, a clear visible light image of the side of the car body is captured by the array camera with normal exposure, and the position of the door lock pin is detected and located by a deep learning algorithm; then, the line laser is controlled to emit a high-power line laser, and the exposure time of the array camera is adjusted and shortened so that only a laser light strip image can be imaged; then, only the laser light strip at the position of the door lock pin is reconstructed by line structured light in three dimensions; if the laser light strip at the position is judged to be a straight line, it is judged that the door lock pin is not inserted into the lock pin hole; if the laser light strip is judged not to be a straight line segment, it is judged that the door lock pin has been inserted into the lock pin hole.

[0022] In the specific implementation, the line laser 10 and the area array camera 20 are pre-installed at the set position (see Figure 1), the set position is the door lock pin state detection station of the boxcar, a pole 30 is installed at a position 1.5 meters away from the side of the car 1, and a line laser 10 is installed on the pole 30. The height of the line laser 10 is the height position of the door lock pin 2. The line laser 10 projects a horizontal laser plane to the car 1. The horizontal laser plane corresponds to the gap between the door lock pin seat 3 and the lower lock pin hole 5 of the upper side beam 4. The laser surface emission angle of the line laser 10 is at least 60°, which can ensure a large horizontal coverage. At the same time, an area array camera 20 is installed on the pole 30 corresponding to 0.5 meters below the line laser 10. The area array camera 20 takes pictures of the side of the car 1. The field of view of the area array camera 20 covers the image at the laser light strip. The horizontal field angle of the area array camera 20 is at least 60°, and a large range of car side images and laser light strip images can be seen at the same time;

[0023] The boxcar drives along the track into the door lock status detection station on the boxcar. The industrial computer obtains the information that the boxcar is in place and triggers the line laser and area array camera to take pictures.

[0024] The industrial computer is also equipped with an image processing server for image acquisition, processing and line structured light stereo vision reconstruction.

[0025] It includes the following specific steps:

[0026] S1. When the vehicle reaches the detection position, the area array camera 20 is controlled to take a picture of the side of the carriage 1 with adaptive exposure to obtain a picture of the side of the carriage;

[0027] S2. Process the side image of the car, use the YOLO deep learning detection and recognition algorithm to detect and identify the approximate position of the upper door lock pin, and draw a detection frame;

[0028] S3, controlling the line laser to project laser light onto the carriage, using the area array camera to take a picture of the laser light strip with a low exposure time, and extracting the center of the light strip of the detection frame obtained in step S2;

[0029] S4, using the line laser structured light vision model to perform 3D reconstruction of the light strips in the detection frame, that is, only reconstructing the laser light strips near the position of the upper door lock pin;

[0030] S5. Determine whether the reconstructed laser light bar is a straight line segment. If so, it means that the laser does not hit the upper door lock pin and the upper door lock pin is not inserted into the lock pin hole. If not, it means that the laser is projected onto the upper door lock pin and the upper door lock pin is inserted into the lock pin hole.

[0031] It uses a line laser and an area array camera to complete the vision-based automatic detection of the insertion status of the door lock pin, providing an automated detection method that no longer relies on manual detection. At the same time, the detection equipment uses two stages: target detection initial positioning and line structured light 3D measurement to complete the detection of the insertion status of the door lock pin. By adjusting the exposure time, the area array camera has both target detection and recognition and image capture camera functions, further reducing the number of sensors used and reducing costs. It performs automated detection based on the fusion of line laser structured light vision and image detection, with high detection efficiency and guaranteed detection accuracy.

[0032] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0033] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for visually detecting the state of a door lock pin of a boxcar, characterized in that: A line laser structured light vision sensor is constructed by installing a line laser and an area array camera on one side of the vehicle to be inspected. First, the area array camera is used to capture a clear visible light image of the side of the vehicle with normal exposure, and the position of the door lock pin is detected and located through a deep learning algorithm. Then, the line laser is controlled to emit a high-power line laser, and the exposure time of the area array camera is adjusted and shortened so that it can only image a laser light strip image. Then, only the laser light strip at the position of the door lock pin is reconstructed by line structured light. If the laser light strip at this location is judged to be a straight line, it is judged that the door lock pin is not inserted into the lock pin hole. If the laser light strip is not judged to be a straight line segment, it is judged that the door lock pin has been inserted into the lock pin hole.

2. A method for visually detecting the state of a door lock pin of a boxcar according to claim 1, characterized in that: A line laser and an area array camera are pre-installed at a set position, which is the door lock pin status detection station of the boxcar. A pole is installed at a position away from the side of the car body, and a line laser is installed on the pole. The height of the line laser is the height of the door lock pin. The line laser projects a horizontal laser plane onto the car body, which corresponds to the gap between the door lock pin seat and the lock pin hole of the upper side beam. At the same time, an area array camera is installed on the pole corresponding to the bottom of the line laser. The area array camera takes pictures of the side of the car body, and the field of view of the area array camera covers the image at the laser light strip.

3. A method for visually detecting the state of a door lock pin of a boxcar according to claim 2, characterized in that: The boxcar drives along the track into the door lock pin status detection station on the boxcar. The industrial computer obtains the information that the boxcar is in place and triggers the line laser and area array camera to take pictures.

4. A method for visually detecting the state of a door lock pin of a boxcar according to claim 3, characterized in that: The industrial computer is also equipped with an image processing server for image acquisition, processing and line structured light stereo vision reconstruction.

5. A method for visually detecting the state of a door lock pin of a boxcar according to claim 3, characterized in that: It includes the following specific steps: S1. When the vehicle arrives at the detection position, the area array camera is controlled to take pictures of the side of the vehicle compartment with adaptive exposure to obtain a side picture of the vehicle compartment; S2. Process the side image of the carriage, use the deep learning detection and recognition algorithm to detect and identify the approximate position of the upper door lock pin, and draw a detection frame; S3, controlling the line laser to project laser light onto the carriage, using the area array camera to take a picture of the laser light strip with a low exposure time, and extracting the center of the light strip of the detection frame obtained in step S2; S4, using the line laser structured light vision model to perform 3D reconstruction of the light strip in the detection frame; S5. Determine whether the reconstructed laser light bar is a straight line segment. If so, it means that the laser does not hit the upper door lock pin and the upper door lock pin is not inserted into the lock pin hole. If not, it means that the laser is projected onto the upper door lock pin and the upper door lock pin is inserted into the lock pin hole.

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