An electric hook automatic alignment and butt joint method and system based on vision and laser ranging

Abstract

The application relates to the technical field of automatic butt joint, in particular to an electric hook automatic alignment butt joint system based on vision and laser ranging, which comprises an industrial camera, an LED light supplement lamp, a cross line laser emitter, a laser ranging module, a four-axis precision butt joint mechanical arm, a replaceable electric hook clamp, an elastic buffer mechanism and a control and algorithm processing unit; the control and algorithm processing unit is connected with the industrial camera, the cross line laser emitter, the laser ranging module and the four-axis precision butt joint mechanical arm; the application can effectively solve the problem that the existing automatic alignment butt joint method simply depends on visual positioning and is easily affected by environmental light changes, target surface reflection and scale changes and other factors, and simply depends on a distance sensor and is difficult to accurately obtain the plane position deviation and attitude deviation of a plug relative to a socket, thereby limiting the automatic alignment stability and butt joint success rate.

Description

Technical Field

[0001] This invention relates to the field of automatic docking technology, specifically to an automatic alignment and docking method and system for electric hooks based on vision and laser ranging. Background Technology

[0002] During the docking operation of electric couplers, power plugs and similar electrical connectors for railway vehicles, it is usually required that the plug and socket be stably connected under conditions of small gap and high precision. Existing docking methods mostly rely on close-range manual observation and manual adjustment, which is not only inefficient, but also poses significant safety hazards in narrow spaces, poor lighting or environments with electrical risks.

[0003] However, existing automatic alignment and docking methods still have shortcomings. Specifically, existing automatic alignment and docking methods that rely solely on visual positioning are easily affected by factors such as changes in ambient light, reflections on the target surface, and changes in scale. On the other hand, relying solely on distance sensors makes it difficult to accurately obtain the planar position deviation and attitude deviation of the plug relative to the socket, which limits the stability of automatic alignment and the success rate of docking. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic alignment and docking method and system for electric hooks based on vision and laser ranging, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An automatic alignment and docking system for electric hooks based on vision and laser ranging includes an industrial camera, an LED fill light, a crosshair laser emitter, a laser ranging module, a four-axis precision docking robotic arm, a replaceable electric hook clamp, an elastic buffer mechanism, and a control and algorithm processing unit. The control and algorithm processing unit is connected to the industrial camera, the crosshair laser emitter, the laser ranging module, and the four-axis precision docking robotic arm, respectively.

[0006] As a preferred embodiment of the present invention, the industrial camera is arranged in front of the working area of ​​the four-axis precision docking robot or near the end of the four-axis precision docking robot. The LED fill light is set in the area near the industrial camera to improve the lighting stability of the docking area. The crosshair laser emitter is used to project a crosshair reference line onto the target docking area. The laser ranging module is used to obtain the distance information from the end of the four-axis precision docking robot to the target plane.

[0007] As a preferred embodiment of the present invention, the replaceable electric hook clamp is used to adapt to electric hook plugs of different specifications. The elastic buffer mechanism is disposed in the insertion direction of the replaceable electric hook clamp to absorb insertion impact and provide feedback buffer displacement information. The control and algorithm processing unit is used to identify target reference marks based on image data collected by industrial cameras, and to determine the spatial pose of the target electric hook plug or target socket by combining the crosshair laser position relationship and laser ranging data.

[0008] An automatic alignment and docking method for electric hooks based on vision and laser ranging includes the following steps: S1, Image Acquisition and Preprocessing: Use an industrial camera to acquire images of the target docking area, and perform distortion correction, image enhancement, and filtering on the acquired images. S2, reference mark recognition, identifies reference marks on plugs or sockets from images to obtain target pixel coordinates; S3, and laser-assisted alignment, uses the positional relationship of the crosshair laser in the image to correct the target center and attitude; S4, Distance and pose calculation, combines laser ranging data, camera calibration parameters and coordinate transformation relationship to obtain the position deviation and attitude deviation of the target relative to the end of the four-axis precision docking robot arm; S5, trajectory planning and automatic docking, generates the motion trajectory of a four-axis precision docking robotic arm based on the posture deviation and performs automatic alignment, insertion and buffer pressing actions.

[0009] As a preferred embodiment of the present invention, the specific steps for distance and pose calculation in S4 are as follows: the control and algorithm processing unit maps the image pixel coordinates to the target coordinate system, and constructs the three-dimensional spatial position of the target by combining the distance value output by the laser ranging module, and then obtains the relative pose of the target based on the transformation relationship between the coordinate system of the four-axis precision docking robot and the target coordinate system.

[0010] As a preferred embodiment of the present invention, the specific steps of performing automatic alignment, insertion and buffer pressing actions in S5 are as follows: the four-axis precision docking robot first performs coarse positioning motion, then performs fine adjustment motion, and when the clamp is detected to be under force or the compression of the elastic buffer mechanism reaches a preset threshold, the control system switches to the compliant insertion stage, thereby reducing the risk of rigid collision.

[0011] As a preferred embodiment of the present invention, the specific steps of identifying the reference mark on the plug or socket from the image and obtaining the target pixel coordinates in S1 are as follows: the control and algorithm processing unit uses template recognition, feature extraction or deep learning recognition algorithms on the preprocessed image data to extract the reference mark pixel coordinates on the target electric hook plug in the image data, and then combines the distance value and calibration parameters output by the laser ranging module to convert the two-dimensional image features into three-dimensional spatial features.

[0012] As a preferred embodiment of the present invention, in step S3, during the alignment process, the industrial camera acquires image data of the area where the target electric hook plug and the target socket are located, the crosshair laser emitter projects a crosshair onto the target area, the laser ranging module outputs the distance value from the end of the robotic arm to the target plane, and the control and algorithm processing unit corrects the target center point and attitude angle according to the reference mark position in the image and the position of the crosshair laser landing point, thereby obtaining a more stable planar positioning result.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the joint acquisition of target plane position, distance and attitude information is realized by the fusion of visual recognition and laser ranging. At the same time, the robotic arm motion trajectory is controlled in stages by the control and algorithm processing unit, which improves the accuracy and success rate of electric hook docking in complex environments. Furthermore, the system's adaptability to different plug specifications and on-site error disturbances is improved by the use of replaceable clamps and elastic buffer mechanisms. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall composition of the electric hook automatic alignment and docking system of the present invention; Figure 2 This is a schematic diagram illustrating the vision-laser fusion positioning principle of the present invention; Figure 3 This is a flowchart illustrating the automatic alignment and docking method of the present invention; Figure 4 This is a schematic diagram showing the relationship between the target coordinate system and the end effector coordinate system of the robotic arm in this invention.

[0015] In the diagram: 1. Industrial camera; 2. LED fill light; 3. Crosshair laser emitter; 4. Laser rangefinder module; 5. Four-axis precision docking robotic arm; 6. Replaceable electric hook clamp; 7. Elastic buffer mechanism; 8. Control and algorithm processing unit. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] To facilitate understanding of the present invention, a more comprehensive description of the invention will be given below with reference to the accompanying drawings, and several embodiments of the invention will be provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0018] For examples, please refer to Figure 1-4 The present invention provides a technical solution: An automatic alignment and docking system for electric hooks based on vision and laser ranging includes an industrial camera 1, an LED fill light 2, a crosshair laser emitter 3, a laser ranging module 4, a four-axis precision docking robotic arm 5, a replaceable electric hook clamp 6, an elastic buffer mechanism 7, and a control and algorithm processing unit 8. The control and algorithm processing unit 8 is connected to the industrial camera 1, the crosshair laser emitter 3, the laser ranging module 4, and the four-axis precision docking robotic arm 5, respectively.

[0019] Furthermore, the industrial camera 1 is positioned in front of the working area of ​​the four-axis precision docking robot arm 5 or near the end of the four-axis precision docking robot arm 5. The LED fill light 2 is set in the area near the industrial camera 1 to improve the lighting stability of the docking area. The crosshair laser emitter 3 is used to project a crosshair reference line onto the target docking area. The laser ranging module 4 is used to obtain the distance information from the end of the four-axis precision docking robot arm 5 to the target plane.

[0020] Furthermore, the replaceable electric hook clamp 6 is used to adapt to electric hook plugs of different specifications. The elastic buffer mechanism 7 is set in the insertion direction of the replaceable electric hook clamp 6 to absorb insertion impact and provide feedback buffer displacement information. The control and algorithm processing unit 8 is used to identify the target reference mark based on the image data collected by the industrial camera 1, and to determine the spatial pose of the target electric hook plug or target socket by combining the crosshair laser position relationship and laser ranging data.

[0021] An automatic alignment and docking method for electric hooks based on vision and laser ranging includes the following steps: S1, Image acquisition and preprocessing: The industrial camera 1 is used to acquire images of the target docking area, and distortion correction, image enhancement and filtering are performed on the acquired images. S2, reference mark recognition, identifies reference marks on plugs or sockets from images to obtain target pixel coordinates; S3, and laser-assisted alignment, uses the positional relationship of the crosshair laser in the image to correct the target center and attitude; S4, Distance and pose calculation: Combining laser ranging data, camera calibration parameters and coordinate transformation relationships, the position and attitude deviations of the target relative to the end of the four-axis precision docking robot arm 5 are obtained. S5, trajectory planning and automatic docking, generates the motion trajectory of the four-axis precision docking robot arm 5 based on the posture deviation and performs automatic alignment, insertion and buffer pressing actions.

[0022] Furthermore, the specific steps for distance and pose calculation in S4 are as follows: the control and algorithm processing unit 8 maps the image pixel coordinates to the target coordinate system, and constructs the target's three-dimensional spatial position by combining the distance value output by the laser ranging module 4. Then, based on the transformation relationship between the coordinate system of the four-axis precision docking robot arm 5 and the target coordinate system, the target's relative pose is obtained.

[0023] Furthermore, the specific steps for performing automatic alignment, insertion, and buffer pressing actions in S5 are as follows: the four-axis precision docking robot arm 5 first performs coarse positioning motion, then performs fine adjustment motion. When the clamp is detected to be under force or the compression amount of the elastic buffer mechanism 7 reaches a preset threshold, the control system switches to the compliant insertion stage, thereby reducing the risk of rigid collision.

[0024] Furthermore, the specific steps in S1 to identify the reference mark on the plug or socket from the image and obtain the target pixel coordinates are as follows: the control and algorithm processing unit 8 uses template recognition, feature extraction or deep learning recognition algorithms on the preprocessed image data to extract the reference mark pixel coordinates on the target electric hook plug in the image data, and then combines the distance value and calibration parameters output by the laser ranging module 4 to convert the two-dimensional image features into three-dimensional spatial features.

[0025] Furthermore, during the alignment process in S3, the industrial camera 1 acquires image data of the area where the target electric hook plug and the target socket are located, the crosshair laser emitter 3 projects a crosshair onto the target area, the laser ranging module 4 outputs the distance value from the end of the robotic arm to the target plane, and the control and algorithm processing unit 8 corrects the target center point and attitude angle according to the reference mark position in the image and the position of the crosshair laser landing point, thereby obtaining a more stable planar positioning result.

[0026] Specific Implementation Cases During the alignment process, the industrial camera 1 acquires image data of the area where the target electric hook plug and the target socket are located, the crosshair laser emitter 3 projects a crosshair onto the target area, the laser ranging module 4 outputs the distance value from the end of the robotic arm to the target plane, and the control and algorithm processing unit 8 corrects the target center point and attitude angle according to the position of the reference mark in the image and the position of the crosshair laser landing point, thereby obtaining a more stable planar positioning result.

[0027] The control and algorithm processing unit 8 first performs distortion correction, grayscale enhancement and noise filtering on the original image. Then, it uses template recognition, feature extraction or deep learning recognition algorithms to extract the reference mark pixel coordinates on the target electric hook plug. Combined with the distance value and calibration parameters output by the laser ranging module 4, the two-dimensional image features are converted into three-dimensional spatial features. The positional relationship of the crosshair laser in the image is used to correct the target center and attitude; The control and algorithm processing unit 8 transforms the coordinate system of the target electric hook plug or target socket to the coordinate system of the end of the four-axis precision docking robot arm 5, and obtains the spatial position deviation and attitude deviation of the target. Based on this, the four-axis precision docking robot arm 5 first performs coarse positioning motion and then performs fine adjustment motion to align the replaceable electric hook clamp 6 with the target plug or socket.

[0028] During the automatic insertion phase, the replaceable electric hook clamp 6 holds the target plug and approaches the target socket along the planned trajectory; when the elastic buffer mechanism 7 detects that the contact load or compression amount reaches the set threshold, the control and algorithm processing unit 8 switches to the compliant docking control mode to reduce the insertion impact and compensate for minor assembly deviations.

[0029] The industrial camera 1, LED fill light 2, crosshair laser emitter 3, laser ranging module 4, four-axis precision docking robotic arm 5, replaceable electric hook clamp 6, elastic buffer mechanism 7, and control and algorithm processing unit 8 used in this invention are all existing known electrical devices, and all can be directly purchased and used on the market. Their structure, circuit, and control principle are all existing known technologies. Therefore, the structure, circuit, and control principle of the industrial camera 1, LED fill light 2, crosshair laser emitter 3, laser ranging module 4, four-axis precision docking robotic arm 5, replaceable electric hook clamp 6, elastic buffer mechanism 7, and control and algorithm processing unit 8 will not be described in detail here.

[0030] All standard parts used in this application can be purchased from the market. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art and are also general components, which are common knowledge in this field.

[0031] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic alignment and docking system for electric hooks based on vision and laser ranging, comprising an industrial camera (1), an LED fill light (2), a crosshair laser emitter (3), a laser ranging module (4), a four-axis precision docking robotic arm (5), a replaceable electric hook clamp (6), an elastic buffer mechanism (7), and a control and algorithm processing unit (8), characterized in that: The control and algorithm processing unit (8) is connected to the industrial camera (1), the crosshair laser emitter (3), the laser ranging module (4), and the four-axis precision docking robot arm (5), respectively.

2. The automatic alignment and docking system for electric hooks based on vision and laser ranging according to claim 1, characterized in that: The industrial camera (1) is positioned in front of the working area of ​​the four-axis precision docking robot (5) or near the end of the four-axis precision docking robot (5). The LED fill light (2) is positioned near the industrial camera (1) to improve the lighting stability of the docking area. The crosshair laser emitter (3) is used to project a crosshair reference line onto the target docking area. The laser ranging module (4) is used to obtain the distance information from the end of the four-axis precision docking robot (5) to the target plane.

3. The automatic alignment and docking system for electric hooks based on vision and laser ranging according to claim 1, characterized in that: The replaceable electric hook clamp (6) is used to adapt to electric hook plugs of different specifications. The elastic buffer mechanism (7) is set in the insertion direction of the replaceable electric hook clamp (6) to absorb the insertion impact and provide feedback buffer displacement information. The control and algorithm processing unit (8) is used to identify the target reference mark according to the image data collected by the industrial camera (1) and determine the spatial pose of the target electric hook plug or target socket by combining the crosshair laser position relationship and laser ranging data.

4. The automatic alignment and docking method for electric hooks based on vision and laser ranging according to claims 1-3, characterized in that, Includes the following steps: S1, Image acquisition and preprocessing: The target docking area image is acquired using an industrial camera (1), and the acquired image is subjected to distortion correction, image enhancement and filtering. S2, reference mark recognition, identifies reference marks on plugs or sockets from images to obtain target pixel coordinates; S3, and laser-assisted alignment, uses the positional relationship of the crosshair laser in the image to correct the target center and attitude; S4, distance and pose calculation, combined with laser ranging data, camera calibration parameters and coordinate transformation relationship, to obtain the position deviation and attitude deviation of the target relative to the end of the four-axis precision docking robot arm (5); S5, trajectory planning and automatic docking, generates the motion trajectory of the four-axis precision docking robot arm (5) based on the position deviation and performs automatic alignment, insertion and buffer pressing actions.

5. The automatic alignment and docking method for electric hooks based on vision and laser ranging according to claim 4, characterized in that: The specific steps for distance and pose calculation in S4 are as follows: the control and algorithm processing unit (8) maps the image pixel coordinates to the target coordinate system, and constructs the target three-dimensional spatial position by combining the distance value output by the laser ranging module (4). Then, based on the transformation relationship between the coordinate system of the four-axis precision docking robot (5) and the target coordinate system, the relative pose of the target is obtained.

6. The automatic alignment and docking method for electric hooks based on vision and laser ranging according to claim 4, characterized in that: The specific steps for performing automatic alignment, insertion and buffer pressing actions in S5 are as follows: The four-axis precision docking robot arm (5) first performs coarse positioning motion, and then performs fine adjustment motion. When the clamp is detected to be under force or the compression amount of the elastic buffer mechanism (7) reaches the preset threshold, the control system switches to the compliant insertion stage, thereby reducing the risk of rigid collision.

7. The automatic alignment and docking method for electric hooks based on vision and laser ranging according to claim 4, characterized in that: The specific steps in S1 to identify the reference mark on the plug or socket in the image and obtain the target pixel coordinates are as follows: The control and algorithm processing unit (8) uses template recognition, feature extraction or deep learning recognition algorithm on the preprocessed image data to extract the reference mark pixel coordinates on the target electric hook plug in the image data, and then combines the distance value and calibration parameters output by the laser ranging module (4) to convert the two-dimensional image features into three-dimensional spatial features.

8. The automatic alignment and docking method for electric hooks based on vision and laser ranging according to claim 4, characterized in that: In the S3 process, during the alignment process, the industrial camera (1) collects image data of the target electric hook plug and the target socket area, the crosshair laser emitter (3) projects a crosshair onto the target area, the laser ranging module (4) outputs the distance value from the end of the robotic arm to the target plane, and the control and algorithm processing unit (8) corrects the target center point and attitude angle according to the reference mark position and the crosshair laser landing point position in the image, thereby obtaining a more stable planar positioning result.

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