Automatic control system of portal crane

Abstract

The invention relates to the technical field of cranes, in particular to an automatic control system of a portal crane, which comprises an identification module, a parameter adjustment module and an execution module which are in signal connection in sequence, the identification module comprises a camera and an image processing unit, the camera is arranged on a lifting appliance of the portal crane, and the image processing unit is arranged on the portal crane. The camera synchronously ascends and descends along with ascending and descending of the lifting appliance, the image processing unit performs feature extraction and comparison on shot images, if the images are identified as concrete beams, the parameter adjusting module adjusts the lifting parameters to be first preset parameters, and if the images are identified as steel beams, the parameter adjusting module adjusts the lifting parameters to be second preset parameters; according to the gantry crane, the identification module can accurately identify whether a hoisting object is a concrete beam or a steel beam in real time, and the operation parameters and the motion logic of the gantry crane are optimized according to the identification result, so that the safety and the efficiency are both considered.

Description

Technical Field

[0001] The invention relates to the technical field of cranes, in particular to an automatic control system of a gantry crane. Background Art

[0002] A gantry crane, also known as a portal crane, is a large-scale lifting equipment. A gantry crane usually includes a gantry, a lifting mechanism, a trolley running mechanism, a carriage running mechanism, a hoisting device, and a control system for controlling the movement of the aforementioned structures. The carriage running mechanism controls the overall movement of the gantry, the trolley running mechanism controls the individual movement of the hoisting device, and the lifting mechanism controls the lifting and lowering of the hoisting device.

[0003] In the construction of modern bridges, buildings and other large-scale projects, gantry cranes are core lifting equipment. Their operating efficiency and safety directly affect the progress and quality of the project. At present, the lifting parameters of gantry cranes, such as lifting speed, acceleration and deceleration rate, anti-sway logic, etc., are mainly set according to the weight of the lifting object, and the differentiated requirements of material properties for the lifting process are generally ignored. Take common concrete beams and steel beams as examples. Concrete beams are highly brittle and have low tensile strength. If vibration shocks are caused by excessive acceleration or sudden stop during lifting, it is very easy to induce internal microcracks or even structural damage. Although steel beams are more ductile, they are prone to elastic deformation or swing due to inertia under long and thin components. If the anti-sway control is insufficient, it may cause high-altitude docking deviation or instability risks.

[0004] Although operators can manually switch preset parameters to adapt to the lifting of concrete beams or steel beams, relying on manual operation has problems such as delayed response and high error rate. Therefore, there is an urgent need for a system that can accurately identify the lifting object as a concrete beam or steel beam in real time, and optimize the operating parameters and motion logic of the gantry crane based on the identification results, so as to balance safety and efficiency in complex construction scenarios. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present application provides an automatic control system for a gantry crane.

[0006] The automatic control system of a gantry crane provided by the present invention adopts the following technical solution: An automatic control system for a gantry crane comprises an identification module, a parameter adjustment module and an execution module which are sequentially connected by signals. The identification module comprises a camera and an image processing unit. The camera is arranged on a sling of the gantry crane. The camera rises and falls synchronously with the rise and fall of the sling. The image processing unit extracts and compares features of the captured image. If a concrete beam is identified, the parameter adjustment module adjusts the lifting parameters of the gantry crane to a first preset parameter for lifting the concrete beam. If a steel beam is identified, the parameter adjustment module adjusts the lifting parameters of the gantry crane to a second preset parameter for lifting the steel beam. The execution module executes the lifting action according to the processing result of the parameter adjustment module.

[0007] Preferably, the feature extraction and comparison of the image processing unit includes image preprocessing, key feature extraction and similarity calculation. The key feature extraction includes extracting surface texture for judging the roughness, sharpness of angular edges, whether there are welds and metallic gloss reflections. The similarity calculation includes comparing the real-time image with the standard samples in the database. The standard samples include concrete beam templates and steel beam templates. If the matching degree is greater than or equal to the matching degree threshold, it is determined to be the material type of the corresponding template.

[0008] Preferably, the recognition module outputs a confidence score, and if the confidence score is insufficient, an alarm is triggered and manual confirmation is requested.

[0009] Preferably, the parameter adjustment module includes a PLC and a parameter storage unit.

[0010] Preferably, the execution module includes a motion controller and an execution mechanism, and the execution mechanism includes a lifting mechanism, a trolley running mechanism and a carriage running mechanism.

[0011] Preferably, in the recognition module, the matching threshold of the similarity calculation is 85%.

[0012] Preferably, the lifting speed of the first preset parameter is smaller than the lifting speed of the second preset parameter, the acceleration of the first preset parameter is smaller than the acceleration of the second preset parameter, the anti-sway mode of the first preset parameter is passive damping, and the anti-sway mode of the second preset parameter is active suppression, the emergency braking of the first preset parameter is a graded deceleration process, and the emergency braking of the second preset parameter is immediately triggered.

[0013] Preferably, it also includes a safety monitoring module, which includes a humidity sensor and a wind speed sensor. The safety monitoring module is set with a humidity threshold and a wind speed threshold. If it is monitored that the current humidity exceeds the humidity threshold or the current wind speed exceeds the wind speed threshold, the safety monitoring module outputs a stop command; when the identification module identifies that the lifting object is a concrete beam, the humidity threshold is lowered and the wind speed threshold is increased; when the identification module identifies that the lifting object is a steel beam, the humidity threshold is increased and the wind speed threshold is lowered.

[0014] Preferably, the image interface of the camera is set with a bar frame. When the camera is lowered with the sling, the execution module is adjusted to align the bar frame in the image interface with the hoisted object. At the same time, the bar frame is gradually filled with the hoisted object until the hoisted object fills the bar frame in the image interface, and the sling and the camera stop being lowered.

[0015] Preferably, the key feature extraction of the image processing unit of the recognition module also includes clarity, the recognition module outputs the weight change result of the hoisted object according to the clarity, and the parameter adjustment module adjusts the preset parameters according to the weight change result.

[0016] The beneficial effects of the present invention are: 1. The automatic control system of the gantry crane of the present invention can accurately identify the hoisting object as a concrete beam or a steel beam in real time through the recognition module, and optimize the operating parameters and motion logic of the gantry crane according to the recognition result, so as to take into account both safety and efficiency; 2. The automatic control system of the gantry crane of the present invention can control the lowering height of the sling according to the radial size of the hoisting object, thereby controlling the length of the rope. For hoisting objects with large radial size and heavy weight, the rope length can be extended to avoid overload and breakage of the rope when hoisting heavy beams. For hoisting objects with small radial size and light weight, the rope length can be shortened to achieve the effect of easy control of the swing amplitude; 3. The automatic control system of the gantry crane of the present invention can detect the weight change of the hoisted object through the bar frame of the image interface and the image clarity in the bar frame, and adjust the preset parameters based on this, so as to achieve more precise control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a module diagram of the automatic control system of the gantry crane in the embodiment of the present application; Figure 2 It is a simple schematic diagram of the image interface of the camera in the embodiment of the present application. DETAILED DESCRIPTION

[0018] The following will be combined Figure 1-Figure 2 The present invention is further illustrated by the following embodiments.

[0019] This embodiment discloses an automatic control system for a gantry crane.

[0020] Reference Figure 1The automatic control system of the gantry crane includes an identification module, a parameter adjustment module and an execution module which are connected in sequence by signals. The identification module is used to identify whether the lifting object is a concrete beam or a steel beam. If it is identified as a concrete beam, the parameter adjustment module adjusts the lifting parameters of the gantry crane to the first preset parameters for lifting concrete beams. If it is identified as a steel beam, the parameter adjustment module adjusts the lifting parameters of the gantry crane to the second preset parameters for lifting steel beams. The execution module executes the lifting action according to the processing results of the parameter adjustment module.

[0021] Reference Figure 1 The recognition module includes a camera and an image processing unit. The camera is set on the gantry crane's spreader. The camera rises and falls synchronously with the rise and fall of the spreader. When the spreader is lowered, the camera approaches the hoisting object and takes pictures. The image processing unit uses an embedded GPU to support real-time image processing and store temporary image data. After the camera captures the image of the hoisting object, the image processing unit extracts and compares the captured image, including image preprocessing, key feature extraction, and similarity calculation. Among them, image preprocessing includes denoising, graying, and edge enhancement. Key feature extraction includes extracting surface texture to determine roughness, sharpness of angular edges, whether there are welds and metallic luster reflections, etc. Similarity calculation includes using a twin neural network to compare the real-time image with the standard sample in the database. The standard sample includes a concrete beam template and a steel beam template. If the matching degree is greater than or equal to the matching degree threshold, it is determined to be the material type of the corresponding template. In this embodiment, the matching degree threshold is 85%. Further, the recognition module outputs a confidence score (0-1). If the confidence is <0.85, an alarm is triggered and manual confirmation is requested.

[0022] Reference Figure 1 The parameter adjustment module includes a PLC and a parameter storage unit. The PLC retrieves one of the preset parameters in the parameter storage unit according to the result given by the identification module and outputs it. The execution module includes a motion controller and an actuator. The motion controller parses the parameter package and generates control instructions to realize the coordinated control of actuators such as lifting mechanisms, trolley running mechanisms, and carriage running mechanisms.

[0023] In summary, the automatic control system of the gantry crane of the present invention can accurately identify the hoisting object as a concrete beam or a steel beam in real time through the identification module, and optimize the operating parameters and motion logic of the gantry crane based on the identification results, thereby taking into account both safety and efficiency.

[0024] Since concrete beams are highly brittle and have low tensile strength, if excessive acceleration or sudden stop causes vibration shock during lifting, it is very easy to induce internal microcracks or even structural damage. In addition, although steel beams are relatively tough, they are easily elastically deformed or swung due to inertia under long and slender components. If the anti-sway control is insufficient, it may cause high-altitude docking deviation or instability risks. Therefore, in the present invention, the lifting speed of the first preset parameter is less than the lifting speed of the second preset parameter, and the acceleration of the first preset parameter is less than the acceleration of the second preset parameter. The anti-sway mode of the first preset parameter is passive damping, that is, mechanical braking takes priority, and the anti-sway mode of the second preset parameter is active suppression, which is achieved through an input shaping algorithm and has a better anti-sway effect. The emergency braking of the first preset parameter is a graded deceleration process, and the emergency braking of the second preset parameter is immediately triggered, which ultimately makes the concrete beam and the steel beam have more suitable operating parameters and motion logic.

[0025] Furthermore, the automatic control system of the present invention also includes a safety monitoring module, which includes a humidity sensor and a wind speed sensor. The safety monitoring module is set with a humidity threshold and a wind speed threshold. If it is monitored that the current humidity exceeds the humidity threshold or the current wind speed exceeds the wind speed threshold, the safety monitoring module outputs a stop command to temporarily suspend the current lifting work. Since humidity has a greater impact on concrete beams and wind speed has a greater impact on steel beams, when the recognition module recognizes that the lifting object is a concrete beam, the humidity threshold is lowered and the wind speed threshold is increased to prevent the adverse consequences caused by the concrete beam absorbing water and increasing weight. When the recognition module recognizes that the lifting object is a steel beam, the humidity threshold is increased and the wind speed threshold is lowered to prevent the steel beam from swinging excessively or overturning due to wind force. Finally, the safety monitoring module of the present invention can adjust the protection logic according to the material of the lifting object to achieve precise protection.

[0026] In the present invention, two ropes are used for lifting between the gantry crane's hoist and the concrete beam, and between the gantry crane and the steel beam, forming an inverted V-shaped lifting structure. Based on this, the actuator of the gantry crane adopts visual servo control in the process of lowering the hoist and the camera. Specifically, a bar frame is set at the center of the camera's image interface, and the bar frame is kept parallel to the hoisting object. When the camera is lowered with the hoist, the actuator adjusts the bar frame in its image interface to align with the hoisting object, and the hoisted object is gradually filled until the hoisting object fills the bar frame in the image interface, and then the hoist and the camera stop lowering. This process can be achieved through machine vision, in which the bar frame is aligned with the hoisting object through an algorithm, or it can be achieved through artificial vision, in which the alignment of the bar frame and the hoisting object is achieved by adding a rotating mechanism to the adjustment. The purpose of using the above-mentioned visual servo control is as follows: for concrete beams or steel beams with larger radial dimensions, the hoist will stop lowering earlier, thereby lengthening the distance between the hoist and the lifting ring on the beam, so that the hoist and the lifting ring are connected by a longer rope, the V-shaped angle is reduced, the load of the rope is reduced, and the rope overload breakage is avoided when lifting heavy beams; and for concrete beams or steel beams with smaller radial dimensions, the hoist will stop lowering later, thereby shortening the distance between the hoist and the lifting ring on the beam, so that the hoist and the lifting ring are connected by a shorter rope, the V-shaped angle is increased, and the swing amplitude is easier to control.

[0027] Based on the above visual servo control, although the sling can be controlled to stop at a suitable distance, the system itself is not clear about the current distance. For this reason, the key feature extraction of the image processing unit of the recognition module also includes clarity. The image processing unit can judge the distance between the sling and the concrete beam or steel beam by judging the clarity of the current picture. Therefore, the shorter the distance, the higher the clarity, and the longer the distance, the lower the clarity. Further, the shorter the distance between the sling and the hoisting object, the smaller the radial size of the hoisting object and the smaller the weight; the longer the distance between the sling and the hoisting object, the larger the radial size of the hoisting object and the larger the weight. Therefore, the recognition module can finally identify the weight change of the hoisting object through clarity comparison, thereby outputting the weight change result, and the parameter adjustment module fine-tunes the parameter value of the preset parameter according to the weight change result, so that the operating parameters are more in line with the hoisting object under the current weight. For example, if it is identified as a concrete beam and the weight becomes larger, the lifting speed of the first preset parameter is reduced and the acceleration is reduced. Finally, the automatic control system of the gantry crane of the present invention can detect the weight change of the hoisting object through vision, and adjust the preset parameters based on this, so as to achieve more precise control.

[0028] The above are all preferred embodiments of the present invention, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An automatic control system for a gantry crane, characterized in that: It includes an identification module, a parameter adjustment module and an execution module which are connected in sequence by signals. The identification module includes a camera and an image processing unit. The camera is arranged on the hoist of the gantry crane. The camera rises and falls synchronously with the rise and fall of the hoist. The image processing unit extracts and compares features of the captured image. If it is identified as a concrete beam, the parameter adjustment module adjusts the lifting parameters of the gantry crane to the first preset parameters for lifting concrete beams. If it is identified as a steel beam, the parameter adjustment module adjusts the lifting parameters of the gantry crane to the second preset parameters for lifting steel beams. The execution module performs the lifting action according to the processing result of the parameter adjustment module.

2. The automatic control system of a gantry crane according to claim 1, characterized in that: The feature extraction and comparison of the image processing unit includes image preprocessing, key feature extraction and similarity calculation. The key feature extraction includes extracting surface texture to determine the roughness, sharpness of angular edges, whether there are welds and metallic gloss reflections. The similarity calculation includes comparing the real-time image with the standard samples in the database. The standard samples include concrete beam templates and steel beam templates. If the matching degree is greater than or equal to the matching degree threshold, it is determined to be the material type of the corresponding template.

3. The automatic control system of a gantry crane according to claim 1, characterized in that: The recognition module outputs a confidence score. If the confidence score is insufficient, an alarm is triggered and manual confirmation is requested.

4. The automatic control system of a gantry crane according to claim 1, characterized in that: The parameter adjustment module includes a PLC and a parameter storage unit.

5. The automatic control system of a gantry crane according to claim 1, characterized in that: The execution module includes a motion controller and an execution mechanism, and the execution mechanism includes a lifting mechanism, a trolley running mechanism and a carriage running mechanism.

6. The automatic control system of a gantry crane according to claim 2, characterized in that: In the recognition module, the matching threshold for similarity calculation is 85%.

7. The automatic control system of a gantry crane according to claim 1, characterized in that: The lifting speed of the first preset parameter is smaller than the lifting speed of the second preset parameter, the acceleration of the first preset parameter is smaller than the acceleration of the second preset parameter, the anti-sway mode of the first preset parameter is passive damping, and the anti-sway mode of the second preset parameter is active suppression, the emergency braking of the first preset parameter is a graded deceleration process, and the emergency braking of the second preset parameter is immediately triggered.

8. The automatic control system of a gantry crane according to claim 1, characterized in that: It also includes a safety monitoring module, which includes a humidity sensor and a wind speed sensor. The safety monitoring module is set with a humidity threshold and a wind speed threshold. If it is monitored that the current humidity exceeds the humidity threshold or the current wind speed exceeds the wind speed threshold, the safety monitoring module outputs a stop command; when the identification module identifies that the lifting object is a concrete beam, the humidity threshold is lowered and the wind speed threshold is increased; when the identification module identifies that the lifting object is a steel beam, the humidity threshold is increased and the wind speed threshold is lowered.

9. The automatic control system of a gantry crane according to claim 1, characterized in that: The image interface of the camera is set with a bar frame. When the camera is lowered along with the hoist, the execution module adjusts the bar frame in the image interface to align with the hoisting object. At the same time, the bar frame is gradually filled with the hoisting object until the bar frame in the image interface is filled with the hoisting object, and the hoist and the camera stop being lowered.

10. The automatic control system of a gantry crane according to claim 9, characterized in that: The key feature extraction of the image processing unit of the recognition module also includes clarity. The recognition module outputs the weight change result of the hoisted object according to the clarity, and the parameter adjustment module adjusts the preset parameters according to the weight change result.

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