Container truck anti-hoisting method and system based on multi-line scanning

Abstract

The invention provides a container truck anti-hoisting method and system based on multi-line scanning, relates to the technical field of container cranes, and aims to avoid additional purchase of special equipment, reduce the number of hardware, simplify the system structure, reduce the debugging process and improve the production efficiency by utilizing an existing cart anti-collision laser scanner and an existing container truck guide laser scanner of a crane. The arrangement positions of existing cart anti-collision laser scanners and container truck guiding laser scanners are verified in use, the functions of the existing scanners are reasonably utilized by means of the existing scanners, interference risks cannot be additionally increased, and normal operation of anti-collision equipment, guiding equipment and the like of the crane is guaranteed; a fusion three-dimensional model is constructed by acquiring various information, and the states of the container truck, the lifting appliance and the surrounding environment can be comprehensively and accurately reflected; and when the container truck abnormally displaces and the speed of the lifting appliance exceeds the limit, an interlocking signal is triggered to stop, a reliable early warning mechanism is provided for preventing the container truck from being lifted, and the loading and unloading operation safety is effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of container cranes, and particularly relates to a method and system for preventing a container truck from being lifted based on multi-line scanning. Background Art

[0002] When a container crane is loading and unloading an external container truck, it is necessary to detect whether the locking pin is opened to avoid lifting the vehicle together with the container when lifting the container, thereby causing a safety accident. The traditional anti-lifting solutions for container trucks mainly have two forms, one based on laser scanning technology and the other based on image recognition technology. Currently, for the anti-lifting systems based on these two technologies, generally additional equipment needs to be installed, the system is complex, there are many hardware components, the cost is high, and the workload of installation, debugging and maintenance is large.

[0003] Chinese Patent (Publication No. CN 106829742 B, Publication Date: June 13, 2017) discloses a laser-based anti-lifting detection system and method, which includes a logic operation unit, a laser scanner and a PLC control system respectively connected to the logic operation unit. The PLC control system sends the values of the trolley encoder and the hoisting encoder to the logic operation unit; the laser scanner sends the scanned container contour data, ground contour data and container truck contour data to the logic operation unit; the logic operation unit receives the data sent by the laser scanner and the PLC control system, performs operations and judgments on the received data, and sends an anti-lifting control signal to the PLC control system, and the PLC control system controls the spreader to stop rising. However, it still needs to configure a dedicated laser scanning device, the system is relatively complex, and the arranged laser scanning device is prone to interference with the operation of the crane itself, affecting the operation of equipment such as crane anti-collision and guidance. Summary of the Invention

[0004] The object of the present invention is to address the deficiencies existing in the prior art, and provide a method and system for preventing a container truck from being lifted based on multi-line scanning. By using the existing anti-collision laser scanner for the trolley and the container truck guiding laser scanner of the crane, it is possible to avoid purchasing additional dedicated equipment, reduce the number of hardware components, simplify the system structure, reduce the debugging process, and moreover, the arranged positions of the existing anti-collision laser scanner for the trolley and the container truck guiding laser scanner have been verified through use. By leveraging the existing scanners and reasonably utilizing their functions, it will not additionally increase the interference risk and ensures the normal operation of equipment such as crane anti-collision and guidance. By obtaining various information to construct a fused three-dimensional model, it is possible to comprehensively and accurately reflect the states of the container truck, spreader and surrounding environment. Separating the container and the container truck from the model and monitoring their motion parameters can promptly detect abnormal situations. When the container truck has abnormal displacement and the spreader speed exceeds the limit, an interlock signal is triggered to stop the vehicle, providing a reliable early warning mechanism for preventing the container truck from being lifted and effectively ensuring the safety of loading and unloading operations.

[0005] The first object of the present invention is to provide a method for preventing the lifting of container trucks based on multi-line scanning, adopting the following solutions:

[0006] Including:

[0007] Based on the container truck contour information, the surrounding environment information of the container truck, the position information of the container truck, and the spacing information between the spreader and the container truck obtained by the large vehicle anti-collision laser scanner and the container truck guiding laser scanner, a fused three-dimensional model is constructed;

[0008] Separate the container and the container truck from the fused three-dimensional model, and monitor the moving speed of the spreader and the displacement of the container truck;

[0009] During the container lifting process, when it is detected that the container truck has abnormal displacement and the spreader speed exceeds the limit, an interlock signal is triggered to stop the vehicle.

[0010] Further, the large vehicle anti-collision laser scanner horizontally scans the crane running track area from one side of the container truck head and one side of the container truck tail respectively, and obtains point cloud data P1 and P2 containing the container truck contour and the surrounding environment information of the container truck. The container truck guiding scanner scans the container truck positioning area from the middle position of the large vehicle anti-collision laser scanner, and obtains point cloud data P3 containing the position information of the container truck and the spacing information between the spreader and the container truck. Based on the point cloud data P1, P2, and P3, a fused three-dimensional model is constructed.

[0011] Further, the separation of the container and the container truck from the fused three-dimensional model includes:

[0012] Extract the moving target features in the set monitoring area below the spreader, obtain the spreader movement features and the container truck movement features, and calculate the moving speed of the spreader and the displacement of the container truck.

[0013] Further, the extraction of the moving target features in the set monitoring area below the spreader includes:

[0014] Separate the background point cloud data from the dynamic target, fit the plane features of the container and locate the container truck, calculate the displacement of the container truck in the vertical direction, and trigger an early warning when the displacement of the container truck in the vertical direction exceeds the set displacement.

[0015] Since the features of the container are obvious, it is easy to find the container in the point cloud data. First, find the container, and then calibrate and locate the container truck according to the relative position between the container and the container truck.

[0016] Further, the triggering of the interlock signal to stop the vehicle needs to meet the following conditions simultaneously:

[0017] The container truck position information exceeds the allowable deviation range within the set time period;

[0018] The spreader speed exceeds the set threshold;

[0019] The missing rate of the point cloud data in the safety monitoring area divided by the truck positioning area is less than the set range.

[0020] Further, the truck positioning area is divided into a positioning area and a safety monitoring area. The safety monitoring area is located above the positioning area. The positioning area is used for truck positioning, and the safety monitoring area is used for detecting the distance between the spreader and the truck.

[0021] Further, the large vehicle anti-collision laser scanner has an adjustable scanning angle in the vertical direction.

[0022] Further, the truck guiding laser scanner is configured to scan the truck positioning area at an inclined angle.

[0023] The second object of the present invention is to provide a truck anti-lifting system based on multi-line scanning as described in the first object, including:

[0024] A scanning and modeling module, configured to: construct a fused three-dimensional model based on the truck contour information, the truck surrounding environment information, the truck position information, and the distance information between the spreader and the truck obtained by the large vehicle anti-collision laser scanner and the truck guiding laser scanner;

[0025] A monitoring module, configured to: separate the container and the truck from the fused three-dimensional model, and monitor the moving speed of the spreader and the displacement of the truck;

[0026] A braking determination module, configured to: during the container hoisting process, when an abnormal displacement of the truck is detected and the speed of the spreader exceeds the limit, trigger an interlock signal to stop the vehicle.

[0027] Further, the large vehicle anti-collision laser scanner horizontally scans the crane running track area from one side of the truck head and one side of the truck tail respectively, and obtains point cloud data P1 and P2 containing the truck contour and the truck surrounding environment information. The truck guiding scanner scans the truck positioning area from the middle position of the large vehicle anti-collision laser scanner, and obtains point cloud data P3 containing the truck position information and the distance information between the spreader and the truck. Based on the point cloud data P1, P2, and P3, a fused three-dimensional model is constructed.

[0028] Compared with the prior art, the advantages and positive effects of the present invention are:

[0029] In view of the problem that a dedicated laser scanning device needs to be configured currently for the anti-lifting detection and control of the container truck, which results in a complex system, by utilizing the existing anti-collision laser scanners for the crane trolley and the laser scanners for guiding the container truck, the additional purchase of dedicated equipment is avoided, the number of hardware components is reduced, the system structure is simplified, and the debugging process is reduced. Moreover, the layout positions of the existing anti-collision laser scanners for the crane trolley and the laser scanners for guiding the container truck have been verified through use. By leveraging the existing scanners and reasonably utilizing their functions, no additional interference risks are added, ensuring the normal operation of equipment such as anti-collision and guiding devices for the crane. By obtaining various information to construct a fused three-dimensional model, the states of the container truck, spreader, and the surrounding environment can be comprehensively and accurately reflected. Separating the container and the container truck from the model and monitoring their motion parameters can promptly detect abnormal situations. When the container truck has an abnormal displacement and the speed of the spreader exceeds the limit, an interlock signal is triggered to stop the vehicle, providing a reliable early warning mechanism for preventing the container truck from being lifted and effectively ensuring the safety of the loading and unloading operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation to the invention.

[0031] Figure 1 Schematic diagrams of the anti-collision laser scanners for the crane trolley and the laser scanners for guiding the container truck in one or more embodiments of the present invention.

[0032] Figure 2 Schematic flow diagrams of the method for preventing the container truck from being lifted based on multi-line scanning in one or more embodiments of the present invention.

[0033] In the figures, 1. First anti-collision laser scanner for the crane trolley; 2. Second anti-collision laser scanner for the crane trolley; 3. Laser scanner for guiding the container truck; 4. Data fusion controller; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Embodiment 1

[0035] In a typical embodiment of the present invention, as Figure 1 - Figure 2 shown, a method for preventing the container truck from being lifted based on multi-line scanning is provided.

[0036] The method for preventing the container truck from being lifted based on multi-line scanning includes:

[0037] Based on the container truck contour information, container truck surrounding environment information, container truck position information, and the spacing information between the spreader and the container truck obtained by the anti-collision laser scanners for the crane trolley and the laser scanner for guiding the container truck 3, a fused three-dimensional model is constructed;

[0038] The container and the container truck are separated from the fused three-dimensional model, and the motion speed of the spreader and the displacement of the container truck are monitored;

[0039] During the container hoisting process, when abnormal displacement of the truck is detected and the spreader speed exceeds the limit, an interlock signal is triggered to stop the vehicle.

[0040] In this embodiment, as Figure 1 shown, the anti-collision laser scanners for the trolley scan the crane running track area horizontally from one side of the truck head and the other side of the truck tail respectively, and the truck guiding scanner scans the truck positioning area from the middle position of the anti-collision laser scanners for the trolley. After scanning, point cloud data is obtained.

[0041] As Figure 2 shown, the method for preventing the truck from being lifted based on multi-line scanning specifically includes:

[0042] S1: The anti-collision laser scanners for the trolley scan the crane running track area to obtain point cloud data P1 and P2 containing the truck contour and the environmental information around the truck. The truck guiding scanner scans from the middle position of the anti-collision laser scanners for the trolley to obtain point cloud data P3 containing the truck position information and the spacing information between the spreader and the truck. Based on the point cloud data P1, P2, and P3, a fused three-dimensional model is constructed.

[0043] S2: Perform spatio-temporal alignment on P1, P2, and P3 to construct a fused three-dimensional model.

[0044] S3: Extract the moving target features within a set monitoring area below the spreader to obtain the spreader motion features and the truck motion features, and calculate the motion speed of the spreader and the displacement of the truck. In this embodiment, the set monitoring area is a 5m×5m monitoring area below the spreader, and the moving target features within this set monitoring area are extracted.

[0045] S4: When abnormal displacement of the truck is detected and the spreader speed exceeds the limit, an interlock signal is triggered to stop the vehicle.

[0046] In this embodiment, the point cloud data obtained by the anti-collision laser scanners for the trolley and the truck guiding laser scanner 3 are fused through the data fusion controller 4 to construct a fused three-dimensional model.

[0047] Among them, there are two anti-collision laser scanners for the trolley, namely the anti-collision laser scanner one 1 installed on one side of the truck head and the anti-collision laser scanner two 2 installed on the other side of the truck tail, which are configured to horizontally scan the obstacles in the track area on both sides and have an adjustable scanning angle of ±10° to ±30° in the vertical direction.

[0048] The vertical scanning angle of the anti-collision laser scanners for the trolley is realized through a mechanical deflection bracket, and its vertical coverage area includes the space range of 2 - 5 meters below the spreader, and the scanning frequency is not less than 25Hz.

[0049] The truck guide laser scanner 3 is installed at the middle position of the large truck anti-collision laser scanner, and is configured to scan the container truck positioning area at an inclined angle. The container truck positioning area is a set monitoring area, specifically a 5m×5m monitoring area under the spreader, and is divided into dynamic monitoring sub-areas. Among them, the division of the dynamic monitoring sub-areas includes:

[0050] Positioning area: a vertical range of 0 - 2 meters, used for precise positioning of the container truck, with a point cloud density ≥ 100 points / ㎡;

[0051] Safety monitoring area: a vertical range of 2 - 5 meters, used for detecting the distance between the spreader and the container truck, with a point cloud density ≥ 50 points / ㎡.

[0052] As Figure 1 shown, the data fusion controller 4 is used to perform spatial registration and three-dimensional modeling on the data of the large truck anti-collision laser scanner and the container truck guide laser scanner 3, and output an anti-lifting control instruction through a multi-level decision-making algorithm.

[0053] After obtaining the point cloud data, the braking instruction is determined through a multi-level decision-making algorithm to issue a braking signal. To execute this multi-level decision-making algorithm, the data fusion controller 4 includes:

[0054] Using the primary spatial registration module, establish the coordinate system mapping relationship of the data of the large truck anti-collision laser scanner and the container truck guide laser scanner 3, with a registration error ≤ 3cm;

[0055] Using the secondary feature matching module, perform target recognition based on the container contour features, with a matching accuracy of ±5cm;

[0056] Using the tertiary dynamic risk assessment module, generate a safety index by comprehensively considering the spreader movement speed v and the vertical position deviation Δd of the container truck: when v > 0.5m / s and Δd > 30cm, trigger an emergency braking instruction.

[0057] The data fusion controller 4 also includes:

[0058] The hardware synchronization module adopts the IEEE 1588 precise time protocol to ensure that the data acquisition time deviation of each scanner < 1ms;

[0059] The fail-safe interlock unit, when the data conflict of the scanner exceeds the threshold, preferentially executes the hoisting stop instruction.

[0060] Among them, the program running inside the data fusion controller 4 includes three parallel threads of required laser point cloud processing, multi-target tracking, and safety situation assessment. The threads exchange data through shared memory, and the response delay < 5ms.

[0061] Among them, the program running inside the data fusion controller 4 includes three parallel threads for required laser point cloud processing, multi-target tracking, and safety situation assessment. The threads exchange data through shared memory, and the response delay is <5 ms. The laser point cloud processing thread receives the original point cloud data from the large vehicle anti-collision and container truck positioning scanners, filters and denoises the data, constructs a fused three-dimensional model of the monitoring area, preliminarily extracts the features of the target container truck and container through point cloud segmentation and clustering analysis, and outputs the target information to the shared memory; the multi-target tracking thread obtains the point cloud processing results from the shared memory, calculates the positions of the target container truck and container in real time, and outputs the tracking list to the shared memory; the safety situation assessment thread reads the tracking information of the target container truck and container from the shared memory, calculates their relative displacement parameters, evaluates the risk of the container truck being lifted, generates corresponding braking signals to the crane control system, and realizes the function of preventing the container truck from being lifted.

[0062] In step S3, extract the features of moving targets within the set monitoring area below the spreader, including: separating the background point cloud data from the dynamic targets, fitting the planar features of the container, calculating the displacement of the container truck in the vertical direction, and triggering an alarm when the displacement of the container truck in the vertical direction exceeds the set displacement.

[0063] Step S3 specifically includes:

[0064] Separate the background point cloud and dynamic targets based on the density clustering algorithm (DBSCAN);

[0065] Use the RANSAC algorithm to fit the planar features of the container;

[0066] Calculate the displacement of the container truck in the vertical direction, and trigger an alarm when the displacement > 0.3 m.

[0067] The fused three-dimensional model integrates the data from the large vehicle anti-collision laser scanner and the container truck guiding laser scanner 3, and comprehensively reflects the spatial state of the operation scene. Therefore, the fused three-dimensional model includes information related to the container truck, information related to the spreader, and information about the surrounding environment.

[0068] The information related to the container truck includes the position information of the container truck, the contour information of the container truck, and the attitude information of the container truck. The position information of the container truck includes the lateral, longitudinal positions on the track and the height in the vertical direction. The contour information of the container truck includes the length, width, and external contour of the container truck, which is used to judge the overall shape and boundary of the container truck. The attitude information of the container truck includes the inclination angle of the container truck vehicle, whether it is horizontal, etc. The information related to the container truck is used to judge whether the container truck is in a normal parked state.

[0069] The spreader-related information includes the position information of the spreader and the motion state information of the spreader. The position information of the spreader includes the coordinate position in the three-dimensional space, especially the relative position relationship between the spreader and the container truck, such as the spacing data between the spreader and the container truck. The motion state information of the spreader includes the moving speed of the spreader, which is the key basis for the three-level dynamic risk assessment module to judge whether to trigger the emergency braking instruction.

[0070] The surrounding environment information includes the obstacle information in the track area and the terrain and fixed facility information of the operation site. The obstacle information in the track area includes the position, shape and size of the obstacles. This information is collected by the large vehicle anti-collision laser scanner and integrated into the three-dimensional model to avoid the collision between the large vehicle and the obstacles and judge the safety of the operation environment. The terrain and fixed facility information of the operation site includes the flatness of the ground, the positions of the surrounding buildings and equipment, providing a background reference for the entire operation scenario, helping the system to comprehensively understand the operation environment and accurately judge whether there are potential risks in the movement of the container truck and the spreader.

[0071] As Figure 2 shown, triggering the interlock signal to stop requires simultaneously meeting:

[0072] The container truck position information exceeds the allowable deviation range within the set time period;

[0073] The spreader speed exceeds the set threshold;

[0074] The missing rate of the point cloud data in the safety monitoring area divided by the container truck positioning area is less than the set range.

[0075] In this embodiment, according to the scanning frequency of the large vehicle anti-collision laser scanner, the set threshold of the spreader speed, and the point cloud distribution in the safety monitoring area, the generation conditions of the three-level braking signal in step S4 need to be simultaneously met:

[0076] The container truck positioning points exceed the allowable deviation range for 3 consecutive frames of data;

[0077] The spreader speed exceeds 110% of the set threshold;

[0078] The point cloud missing rate in the safety monitoring area < 20%.

[0079] Embodiment 2

[0080] In another typical implementation manner of the present invention, as Figure 1 - Figure 2 shown, a container truck anti-lifting system based on multi-line scanning is given.

[0081] A container truck anti-lifting system based on multi-line scanning, comprising:

[0082] A scanning and modeling module, configured to: construct a fused three-dimensional model based on the container truck profile information, the surrounding environment information of the container truck, the position information of the container truck, and the spacing information between the spreader and the container truck obtained by the large vehicle anti-collision laser scanner and the container truck guiding laser scanner 3;

[0083] A monitoring module, configured to: separate the container and the container truck from the fused three-dimensional model, and monitor the movement speed of the spreader and the displacement of the container truck;

[0084] A braking determination module, configured to: during the container hoisting process, when detecting an abnormal displacement of the container truck and an excessive speed of the spreader, trigger an interlock signal to stop the vehicle.

[0085] Among them, the large vehicle anti-collision laser scanner horizontally scans the crane operation track area from one side of the container truck head and one side of the container truck tail respectively, and obtains point cloud data P1 and P2 including the container truck profile and the surrounding environment information of the container truck. The container truck guiding scanner scans the container truck positioning area from the middle position of the large vehicle anti-collision laser scanner, and obtains point cloud data P3 including the position information of the container truck and the spacing information between the spreader and the container truck. Based on the point cloud data P1, P2, and P3, a fused three-dimensional model is constructed.

[0086] Among them, the working process of the container truck anti-lifting system based on multi-line scanning refers to the container truck anti-lifting method based on multi-line scanning in Embodiment 1, which will not be elaborated here.

[0087] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preventing container cranes from being lifted based on multi-line scanning, characterized in that, Including: Based on the container truck contour information, the surrounding environment information of the container truck, the position information of the container truck, and the spacing information between the spreader and the container truck obtained by the large vehicle anti-collision laser scanner and the container truck guiding laser scanner, a fused three-dimensional model is constructed. Separate the container and the container truck from the fused three-dimensional model, and monitor the movement speed of the spreader and the displacement of the container truck. During the container hoisting process, when it is detected that the container truck has abnormal displacement and the spreader speed exceeds the limit, trigger an interlock signal to stop the vehicle.

2. The method for preventing the container crane from being lifted based on multi-line scanning according to claim 1, characterized in that, The large vehicle anti-collision laser scanner horizontally scans the crane running track area from one side of the container truck head and the other side of the container truck tail respectively, to obtain point cloud data P1 and P2 containing the container truck contour and the surrounding environment information of the container truck. The container truck guiding scanner scans the container truck positioning area from the middle position of the large vehicle anti-collision laser scanner, to obtain point cloud data P3 containing the position information of the container truck and the spacing information between the spreader and the container truck. Based on the point cloud data P1, P2, and P3, a fused three-dimensional model is constructed.

3. The method for preventing the container crane from being lifted based on multi-line scanning according to claim 2, wherein, The separating the container and the container truck from the fused three-dimensional model includes: Extract the moving target features within a set monitoring area below the spreader, obtain the spreader movement features and the container truck movement features, and calculate the movement speed of the spreader and the displacement of the container truck.

4. The method for preventing the container crane from being lifted based on multi-line scanning according to claim 3, characterized in that, The extracting the moving target features within a set monitoring area below the spreader includes: Separate the background point cloud data from the dynamic target, fit the container plane features and locate the container truck, calculate the displacement of the container truck in the vertical direction, and trigger an early warning when the displacement of the container truck in the vertical direction exceeds the set displacement amount.

5. The method for preventing the container crane from being lifted based on multi-line scanning according to claim 2, wherein, The triggering the interlock signal to stop the vehicle needs to meet simultaneously: The container truck position information exceeds the allowable deviation range within a set time period; The spreader speed exceeds the set threshold; The missing rate of the point cloud data in the safety monitoring area divided from the container truck positioning area is less than the set range.

6. The method for preventing a container truck from being lifted based on multi-line scanning according to claim 5, wherein The container truck positioning area is divided into a positioning area and a safety monitoring area. The safety monitoring area is located above the positioning area. The positioning area is used for container truck positioning, and the safety monitoring area is used for detecting the spacing between the spreader and the container truck.

7. The container crane anti-lifting method based on multi-line scanning according to claim 1, wherein The large vehicle anti-collision laser scanner has an adjustable scanning angle in the vertical direction.

8. The method for preventing container crane from lifting based on multi-line scanning according to claim 1, wherein, The container truck guiding laser scanner is configured to scan the container truck positioning area at an inclined angle.

9. A gantry crane anti-lifting system based on multi-line scanning, characterized in that, Including: A scanning and modeling module, configured to: based on the container truck contour information, the surrounding environment information of the container truck, the position information of the container truck, and the spacing information between the spreader and the container truck obtained by the large vehicle anti-collision laser scanner and the container truck guiding laser scanner, construct a fused three-dimensional model; a monitoring module, configured to: separate the container and the container truck from the fused three-dimensional model, and monitor the movement speed of the spreader and the displacement of the container truck. A braking determination module, configured to: during the container hoisting process, when it is detected that the container truck has abnormal displacement and the spreader speed exceeds the limit, trigger an interlock signal to stop the vehicle.

10. The gantry crane anti-lifting system based on multi-line scanning according to claim 9, characterized in that, The large vehicle anti-collision laser scanner horizontally scans the crane running track area from one side of the container truck head and the other side of the container truck tail respectively, to obtain point cloud data P1 and P2 containing the container truck contour and the surrounding environment information of the container truck. The container truck guiding scanner scans the container truck positioning area from the middle position of the large vehicle anti-collision laser scanner, to obtain point cloud data P3 containing the position information of the container truck and the spacing information between the spreader and the container truck. Based on the point cloud data P1, P2, and P3, a fused three-dimensional model is constructed.

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