Anti-collision protection method for gantry crane boom

Abstract

The invention discloses an anti-collision protection method for a gantry crane boom, and belongs to the technical field of safety detection. According to the method, a multi-sensor fusion framework is adopted, 32-line laser radars are deployed in a cantilever crane and an electrical room, and 360-degree non-blind area monitoring is achieved; an anti-interference camera is synchronously configured, and a three-dimensional environment is reconstructed in real time through a point cloud and video fusion technology. Based on a dynamic grading early warning mechanism, three-level threshold values of the cantilever crane and the electrical room are set, and sound-light alarm, picture automatic focusing and PLC linkage control are triggered. According to the method, in practical application, the accident rate of collision between the crane boom and the ship structure is effectively reduced, and the operation safety and the operation efficiency of equipment are improved.

Description

Technical Field

[0001] This invention relates to a collision protection method for the boom of a gantry crane, which belongs to the technical field of safety detection. Background Technology

[0002] Gantry cranes, located in shipyards and outfitting wharves, are primarily used for lifting and installing various materials during sectional loading and outfitting operations. During operation, they are prone to collisions with obstacles such as ships, other cranes, and buildings, leading to equipment damage, ship losses, and even personnel injuries. Traditional collision avoidance systems mainly rely on ultrasonic and infrared sensors, which suffer from large blind spots and poor environmental adaptability, making them unsuitable for the safety requirements of complex shipyard environments. LiDAR, by emitting laser beams and receiving reflected signals, can acquire real-time three-dimensional point cloud data of target objects, achieving centimeter-level accuracy in environmental perception. Applying LiDAR to gantry crane collision avoidance systems can effectively solve the problems of limited detection range and insufficient target recognition capabilities of traditional sensors.

[0003] Furthermore, the risk of collisions between gantry cranes and the ship's towering structure increases dramatically during the construction of large container ships. Traditional manual monitoring relies on the experience of the pilots and ground command, which is prone to response delays and misjudgments. Therefore, there is an urgent need to develop an automated collision avoidance protection system that can mitigate collisions through real-time monitoring and intelligent early warning.

[0004] Existing technologies, such as patent CN117657968A, involve setting up a data acquisition terminal on the gantry crane; constructing a group model of the gantry cranes to obtain the boom amplitude, boom rotation angle, absolute position of the gantry crane rotation center from the coordinate origin, boom height, and absolute distance from the projection point of the boom apex to the coordinate origin; presetting anti-collision deceleration distance thresholds, stopping distance thresholds, and height distance thresholds, and setting height verification programs and position verification programs that match the thresholds; exchanging data with adjacent gantry cranes to obtain the absolute distance difference and boom height difference between adjacent gantry cranes; calling the verification program to verify the boom height difference and absolute distance difference respectively, and controlling the gantry crane boom to operate normally, decelerate, or stop based on the verification results.

[0005] Disadvantages of existing technology: 1. Inability to detect non-gantry crane obstacles: It only obtains the gantry crane's own motion parameters (amplitude Fx, angle θx) through encoders, and relies entirely on geometric models to calculate collision risks, making it unable to detect collision risks with ship structures. 2. Poor environmental adaptability: It lacks real-time physical sensing capabilities and has no actual environmental sensing sensors. 3. Weak multi-target processing capability: It only processes data exchange between adjacent gantry cranes and cannot track moving obstacles. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a collision avoidance protection system and method for a gantry crane boom. Through multi-sensor fusion perception, three-dimensional environment reconstruction, and hierarchical early warning control, it achieves accurate detection and real-time response to various obstacles, thereby improving the safety and efficiency of gantry crane operations.

[0007] The technical solution adopted in this invention is: a method for preventing collisions with the boom of a gantry crane, comprising the following steps: S1. Perception Layer Deployment: Determine the requirements of the gantry crane operation scenario and deploy multi-sensor fusion perception equipment in the boom and electrical room, including a 32-line lidar and anti-interference cameras; S2. Data Processing: Based on the ROS framework, sensor data is received, and through decoding, filtering, noise reduction, and distance calculation, the 3D environment is reconstructed and obstacles are identified. S3. Tiered early warning configuration: Preset three-level distance thresholds between the boom and the electrical room: information area, warning area, and alarm, and set corresponding early warning procedures and response strategies; S4. Execution Control: Based on the location of the obstacle, trigger visual prompts, audible and visual alarms, and PLC linkage control to achieve safe operation and adjustment of the gantry crane boom.

[0008] Furthermore, the specific process for deploying the perception layer in step S1 includes: S101. Install two 32-line lidar units on the left and right sides of the gantry crane boom, one unit at the bottom, and two units in the electrical room to achieve 360° blind-spot-free coverage. S102, each LiDAR on both sides of the boom is equipped with a 4-megapixel anti-interference camera, the LiDAR at the base of the boom is equipped with a camera, and an additional camera is installed on each side of the rear of the equipment room. S103. Ensure that the lidar protection level reaches IP67, and that the camera has night imaging and anti-metal interference capabilities.

[0009] Furthermore, the specific process of data processing in step S2 includes: S201 uses C++ encoding, subscribes to LiDAR data based on the ROS framework, and decodes it into PCL PointCloud format through RoboSense Driver; S202. Calculate the distance between each point in the point cloud data and the boom using pointers, and combine OpenCV to process the RGB image data from the camera to achieve the fusion of point cloud and video. S203. A visual interface is built using VTK and Qt to simultaneously display real-time video, point cloud scatter plots, and obstacle distance data.

[0010] Furthermore, the specific parameters for the tiered early warning configuration in step S3 are as follows: Boom area: Information zone threshold 5m, warning zone threshold 3m, alarm zone threshold 1m; Electrical room area: Information zone threshold 1.5m, warning zone threshold 1m, alarm zone threshold 0.5m; All thresholds can be adjusted in the background, and the early warning program is associated with regional identification and dynamic response logic.

[0011] Furthermore, the specific process of executing control in step S4 includes: S401. When an obstacle is in the information area, the obstacle's position and distance data are displayed normally on the visualization interface. S402. When an obstacle enters the warning zone, the lights flash and a voice prompt is triggered, and the screen focuses on the risk area. S403. When an obstacle reaches the alarm zone, an audible and visual alarm is activated, and the gantry crane boom is slowed down or stopped via PLC linkage.

[0012] The beneficial effects of this invention are as follows: Addressing the problems of large blind spots and poor environmental adaptability of existing sensors, this system adopts a multi-sensor fusion architecture: five 32-line LiDARs are deployed on the boom, and two identical LiDARs are deployed in the electrical room, achieving 360° blind-spot-free monitoring; simultaneously, five 4-megapixel anti-interference cameras are configured, and the 3D environment is reconstructed in real time through point cloud and video fusion technology. Based on a dynamic hierarchical early warning mechanism, three threshold levels are set for the boom and electrical room, triggering audible and visual alarms, automatic image focusing, and PLC linkage control.

[0013] This method overcomes the limitation of only being able to identify adjacent gantry cranes, and can accurately detect various static and dynamic obstacles such as ship structures and buildings. The fusion design of lidar and cameras can cope with complex environments such as rain, fog, and nighttime, exhibiting outstanding anti-interference capabilities. Simultaneously, the three-level early warning mechanism combined with visual interaction provides a rapid and accurate response, reducing the risk of operator misjudgment. It supports background threshold adjustment, and the visual interface is intuitive and easy to understand, conforming to on-site operating habits. This invention effectively solves the collision risk problem in gantry crane operations through multi-sensor fusion perception, intelligent data processing, and hierarchical early warning control, improving equipment operating safety and operational efficiency, and is suitable for complex operating scenarios such as shipyards and outfitting docks. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a layout diagram of a lidar system.

[0016] Figure 2 This is a system architecture diagram of the control and data processing unit. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0021] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0022] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0023] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0024] S1. Perception Layer: The perception layer adopts a multi-sensor fusion architecture, the core of which is to achieve high-precision environmental perception without blind spots.

[0025] (1) A 32-line three-dimensional lidar (IP67 protection rating) is selected, with 5 units installed in the boom area (2 on the left and right sides, and 1 at the bottom), and 2 units installed in the electrical room. This enables blind-spot-free obstacle detection within the 360° rotation range of the gantry crane boom, with a coverage radius ≥80m and a height range ≥50m. At a detection distance of 5 meters, the vertical blind zone is 246 mm and the horizontal blind zone is 8.8 mm, meeting the boom's anti-collision accuracy requirements.

[0026] Each radar on both sides of the boom has one corresponding camera, and the lidar at the base of the boom has one corresponding camera, for a total of five cameras, covering the blind spots of the boom operation. In addition, one camera is also installed on each side of the rear of the machine room to ensure that the operator can observe the positional relationship between the gantry crane and the boarding tower below, as well as the ship structure.

[0027] S2. The data processing stage focuses on efficient fusion and accurate calculation, and is implemented using C++. The UI uses Qt to display radar and camera data. It subscribes to LiDAR data based on the ROS framework and uses RoboSense's Driver to decode radar point cloud data, which is collectively referred to as PCL's PointCloud format. It uses pointers to calculate the distance to the boom point by point and judges obstacles.

[0028] The UI is displayed using VTK and QT. Camera images are streamed and decoded using the camera SDK to extract RGB image data, which is then displayed using OpenCV and QWidget. After radar detects the obstacle, it displays it on the image and plays an audio signal to inform the driver.

[0029] The driver's cab is equipped with a monitor developed using Vue+Qt. The left side displays real-time video, while the right side shows a point cloud scatter plot and distance data. When an obstacle enters the alarm zone, the screen automatically zooms in on the risk area, simultaneously triggering a voice prompt (volume adjustable) and flashing lights.

[0030] S3. Tiered Early Warning Configuration: Differentiated three-tiered thresholds are set based on the risk level of the work scenario. For the boom area, given its wide operating range, a 5m information zone, a 3m warning zone, and a 1m alarm zone are defined. For the electrical room, due to its relatively compact space, a 1.5m information zone, a 1m warning zone, and a 0.5m alarm zone are defined. Alarm thresholds are set for each area, and all thresholds can be flexibly adjusted in the backend. The early warning program is linked to the area identification logic to ensure accurate response methods for different risk levels.

[0031] S4. The execution control link realizes multi-dimensional early warning and linkage management. When the obstacle is in the information zone, the interface displays relevant data normally to remind the driver to pay attention; after entering the warning zone, the lights flash and trigger the voice prompt, and the screen automatically focuses on the risk area to enhance the driver's vigilance; when reaching the alarm zone, the sound and light alarm is activated, and at the same time, the gantry crane boom is controlled to decelerate or stop running through the PLC linkage, forming a closed loop from early warning to management.

[0032] On-site test results: The system's average response time was 280 milliseconds, which is better than the design target (≤300 milliseconds); the LiDAR detection error in rain and fog was <3%; the camera's effective recognition distance at night was ≥15 meters; a total of 127 warnings were triggered during the test, with an effective alarm rate of 98% and a false alarm rate of 2%, and no collision accidents occurred.

[0033] This method enables omnidirectional dynamic obstacle tracking: Utilizing the specific spatial deployment of seven 32-line LiDARs, it covers a 20-meter radius around the boom and gantry crane room, achieving 360° blind-spot-free monitoring. The PCL library is used for point cloud filtering, noise reduction, and distance calculation, enabling real-time detection of various obstacles in 3D space and supporting simultaneous tracking of ≥20 targets. A tiered, dynamically adjusted response strategy is implemented. VTK real-time rendering of the point cloud model is overlaid onto the video feed, with red highlighting of alarm areas and automatic image focusing to eliminate driver misjudgment. The anti-interference point cloud processing algorithm ensures that the LiDAR detection error is <3% in rain and fog, and the camera's effective nighttime imaging recognition distance is ≥15 meters, while also suppressing interference from shipyard metal structures.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for collision protection of the boom of a gantry crane, characterized in that, Includes the following steps: S1. Deployment of the perception layer: Determine the requirements of the gantry crane operation scenario and deploy multi-sensor fusion perception equipment in the boom and electrical room, including a 32-line lidar and anti-interference cameras; S2. Data Processing: Based on the ROS framework, sensor data is received, and through decoding, filtering, noise reduction, and distance calculation, the 3D environment is reconstructed and obstacles are identified. S3. Tiered early warning configuration: Preset three-level distance thresholds between the boom and the electrical room: information area, warning area, and alarm, and set corresponding early warning procedures and response strategies; S4. Execution Control: Based on the location of the obstacle, trigger visual prompts, audible and visual alarms, and PLC linkage control to achieve safe operation and adjustment of the gantry crane boom.

2. The anti-collision protection method for the boom of a gantry crane according to claim 1, characterized in that, The specific process for deploying the perception layer in step S1 includes: S101. Install two 32-line lidar units on the left and right sides of the gantry crane boom, one unit at the bottom, and two units in the electrical room to achieve 360° blind-spot-free coverage. S102, each LiDAR on both sides of the boom is equipped with a 4-megapixel anti-interference camera, the LiDAR at the base of the boom is equipped with a camera, and an additional camera is installed on each side of the rear of the equipment room. The S103 lidar has an IP67 protection rating, and the camera has night vision capabilities and resistance to metal interference.

3. The anti-collision protection method for the boom of a gantry crane according to claim 1, characterized in that, The specific process of data processing in step S2 includes: S201 uses C++ coding, subscribes to LiDAR data based on the ROS framework, and decodes it into PCL PointCloud format through RoboSense Driver; S202. Calculate the distance between each point in the point cloud data and the boom using pointers, and combine OpenCV to process the RGB image data from the camera to achieve the fusion of point cloud and video. S203. A visual interface is built using VTK and Qt to simultaneously display real-time video, point cloud scatter plots, and obstacle distance data.

4. The anti-collision protection method for the boom of a gantry crane according to claim 1, characterized in that, The specific parameters for the hierarchical early warning configuration in step S3 are as follows: Boom area: Information zone threshold 5m, warning zone threshold 3m, alarm zone threshold 1m; Electrical room area: Information zone threshold 1.5m, warning zone threshold 1m, alarm zone threshold 0.5m; All thresholds can be adjusted in the background, and the early warning program is associated with regional identification and dynamic response logic.

5. The anti-collision protection method for the boom of a gantry crane according to claim 1, characterized in that, The specific process of executing control in step S4 includes: S401. When an obstacle is in the information area, the obstacle's position and distance data are displayed normally on the visualization interface. S402. When an obstacle enters the warning zone, the lights flash and a voice prompt is triggered, and the screen focuses on the risk area. S403. When an obstacle reaches the alarm zone, an audible and visual alarm is activated, and the gantry crane boom is slowed down or stopped via PLC linkage.

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