Bridge girder hoisting system and positioning method

Abstract

The invention relates to the technical field of bridge engineering construction, in particular to a bridge girder hoisting system and a positioning method.The system collects position information in real time through Beidou positioning terminals of all hoisting points on a hoisting frame, cable force is monitored through pin shaft type force sensors, and after the position information is processed through a Beidou differential service system and a control center, the cable force is transmitted to a main girder hoisting system; and the winch is regulated and controlled to act and early warn abnormity. The positioning method comprises the steps of equipment installation, data acquisition, coordinate calculation, data processing and intelligent regulation and control, millimeter-level positioning achieved through Beidou difference, and lifting point height difference control through double-cable force monitoring and closed-loop control. The invention aims to solve the problems of unbalanced components and potential safety hazards caused by low measurement precision, asynchronous hoisting point displacement and large cable force monitoring error in traditional bridge girder hoisting.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering construction and relates to a bridge main beam hoisting system and a positioning method. Background Art

[0002] The hoisting of bridge main beams is a core step in the construction of long-span bridges. Especially in the construction of heavy components such as steel trusses, high-precision positioning of lifting points, simultaneous control of multiple lifting points, and real-time monitoring of cable tension are required. As bridge construction evolves towards longer spans and intelligent systems, the traditional hoisting process, which relies on encoder measurement, manually operated winches, and single-point cable tension monitoring, can no longer meet the requirements of modern engineering for construction accuracy and safety. The widespread use of non-circulating main cable systems in complex bridge projects poses a greater challenge to monitoring force balance during the hoisting process, necessitating an integrated, intelligent technical solution.

[0003] The traditional method uses an encoder to measure the hoisting height. Due to the elastic deformation and slip error of the wire rope, the vertical positioning error can reach the centimeter level, resulting in asynchronous vertical displacement of the components when lifting at multiple lifting points, causing potential imbalance. The pin sensor is set on the lifting rope, and the measurement deviation exceeds 10% due to friction. It is also unable to monitor the uneven force of each main rope in the non-circulating main rope. When the force of a single main rope exceeds the safety threshold or the force difference is too large, it may cause a breakage accident. Manually operating the winch through an intercom is difficult to adjust the lifting speed of multiple lifting points in real time. The crane parking accuracy and hoisting synchronization are poor, and the risk of manual error is high. Although the maximum bearing capacity of the sling is increased during design, the uneven force of the sling will cause some slings to overload, which will affect the life of the sling and increase safety risks.

[0004] Currently, the process of lifting the steel truss of a suspension bridge from the lifting point to connecting it with the hanger and completing temporary riveting with adjacent steel trusses is usually completed by a cable crane.

[0005] During the transportation process from cable lifting to final connection with the boom, the balance of the steel beam should be maintained as much as possible. In this way, when the adjacent steel trusses are finally connected, the steel trusses can be adjusted as little as possible, thereby improving the connection efficiency.

[0006] In order to maintain the balance of the steel truss during the hoisting process and facilitate adjustments during docking, the hoisting equipment used for hoisting the steel truss is usually equipped with multiple lifting points, that is, multiple load-bearing points are set on the hoisting equipment. Multiple lifting ropes drawn from the cable crane are connected to the lifting points. The balance of the steel truss can be adjusted by adjusting the lifting speed of each lifting point. When the steel truss is hoisted, the lifting ropes are adjusted to maintain the steel truss in an initial balanced state. During the transportation process, manual adjustments are only made when obvious imbalance of the steel beam is manually observed. After reaching the docking range, the relationship between the steel truss and the adjacent steel trusses is manually observed, and each lifting point is controlled to reach the preset point.

[0007] In addition, to ensure uniform force on each rope during lifting, tension sensors are installed at the fixed ends of the ropes to monitor the tension applied to them. During transportation, even when the steel truss maintains balance, the ropes connecting a certain lifting point may not be under load, causing other ropes to be overloaded, posing a safety hazard. While the ropes bear the weight of the steel truss, the tension applied to them is also affected by factors such as friction with the pulleys and the force of the jammer. Because friction is much smaller than the weight of the steel truss and is proportional to the weight shared by the ropes, it is impossible to determine that a rope is sharing the weight of the steel truss if its friction is not under load. Therefore, in the prior art, installing tension sensors on the ropes to directly obtain the tension values ​​applied to them remains the optimal option, based on the premise of determining rope safety. While this design increases the maximum load-bearing capacity of the ropes, uneven force applied to the ropes can lead to overloading of some ropes, shortening their lifespan and increasing safety hazards.

[0008] With the development of Beidou positioning technology, it has gradually been applied in various positioning scenarios. In the hoisting and positioning of steel beams of bridges, Beidou positioning has also gradually been applied. For example: CN219929461U is a cable hoisting and positioning device for a suspension bridge. By introducing Beidou technology, during the hoisting process, it obtains height data in real time through Beidou, and adjusts the height and posture of the steel truss in the air in time through the winch. Since this adjustment method uses the results as the basis for adjustment, if the imbalance of the steel truss during the transfer process is caused by the friction of each lifting rope, this imbalance factor will persist, and due to the signal delay and accuracy error of the Beidou signal, the deviation will not be eliminated immediately and will accumulate within its delay and accuracy error. Therefore, there is a phenomenon of repeated leveling during the transportation process, which causes the steel truss to vibrate during the hoisting process, increasing safety hazards.

[0009] With the development of Beidou positioning technology, it has gradually been applied in various positioning scenarios. In the hoisting and positioning of steel beams of bridges, Beidou positioning has also gradually been applied. For example: CN219929461U is a cable hoisting and positioning device for a suspension bridge. By introducing Beidou technology, during the hoisting process, it obtains height data in real time through Beidou, and adjusts the height and posture of the steel truss in the air in time through the winch. Since this adjustment method uses the results as the basis for adjustment, if the imbalance of the steel truss during the transfer process is caused by the friction of each lifting rope, this imbalance factor will persist, and due to the signal delay and accuracy error of the Beidou signal, the deviation will not be eliminated immediately and will accumulate within its delay and accuracy error. Therefore, there is a phenomenon of repeated leveling during the transportation process, which causes the steel truss to vibrate during the hoisting process, increasing safety hazards.

[0010] According to the search, patent CN212294379U, titled "Long-span Bridge Main Girder Hoisting System Based on Beidou Positioning," achieves three-dimensional positioning through Beidou base stations, positioning terminals, and differential service systems. The control center adjusts the winch movement based on coordinate data. The principle is to use Beidou RTK differential technology to improve positioning accuracy. In the above scheme, Beidou positioning technology significantly improves positioning accuracy compared to traditional encoders; fixed-end cable force monitoring can provide basic force data; manual control is flexible under simple working conditions; however, the Beidou system does not integrate cable force monitoring and car inclination warning, and cannot solve the problem of uneven force on non-circular main cables. Fixed cable force measurement is disturbed by friction, and no cable force difference monitoring model is designed for non-circulating main cables; Manual synchronous control relies on experience, is difficult to deal with dynamic errors, has low efficiency and high safety risks. In view of this, this solution provides a bridge main beam hoisting system and positioning method. It performs initial leveling of the steel truss, obtains the force at each lifting point through pin-type sensors, and hoists until each lifting point is evenly stressed. During the lifting process, the force value of the pin-type sensor is obtained in real time, and compared in real time to ensure that it is within the error range of uniform force. Set the balance error of the steel truss. By acquiring Beidou data in real time and comparing it with the height data, the state of the steel truss is obtained. If the state of the steel truss is within the balance error, it is in a balanced state. If it is greater than the error, it is in an unbalanced state. In the unbalanced state, the steel truss is controlled by the winch to a balanced state. 4. After reaching the predetermined horizontal position, the winch is controlled by Beidou positioning detection to lift the steel beam to the preset position. In steps 3 and 4, the priority should be to ensure that the ropes are evenly stressed during the leveling and lifting process. Summary of the Invention

[0011] The present invention provides a bridge main beam hoisting system and positioning method, which solves the problems of component imbalance and safety hazards caused by low measurement accuracy, asynchronous lifting point displacement, and large cable force monitoring errors in traditional bridge main beam hoisting.

[0012] In order to solve the above problems, the technical solution adopted by the invention is: A bridge main beam hoisting system, comprising: A hanger having a plurality of hanging points; A Beidou positioning terminal is provided at each of the hanging points, and is used to collect the position information of each hanging point in real time and transmit it to the Beidou differential service system; A pin-type load cell, mounted on a sling on the hanger, for monitoring the tension of the lifting rope and transmitting the data to a control center; The Beidou differential service system is used to receive the location information transmitted by the Beidou positioning terminal, calculate the XYZ coordinates of each hanging point, and transmit them to the control center; The control center is used to receive the XYZ coordinates of each lifting point transmitted by the Beidou differential service system and the cable force data transmitted by the pin-type load cell, process the data, calculate the vertical displacement, height difference and lifting speed of each lifting point, and determine whether the cable force is abnormal based on the cable force data. It then issues instructions to the hoisting winches and adjusts the operation of each hoisting winch. When the cable force exceeds the set threshold or the difference between any two cable forces exceeds the set threshold, the alarm device is triggered to sound an alarm. The alarm device is used to send out an alarm signal when the control center determines that the cable tension is abnormal.

[0013] A method for hoisting and positioning a bridge main beam comprises the following steps: S1: setting a Beidou positioning terminal on each lifting point of a hanger, installing a pin-type force sensor at the hanger of the hanger, and setting a lateral pressure sensor on each load-bearing cable; S2: during the lifting process, the Beidou positioning terminal collects the position information of each lifting point in real time and transmits it to the Beidou differential service system, the pin-type force sensor monitors the cable force of the lifting cable in real time and transmits the data to the control center, and the lateral pressure sensor collects the cable force data of the load-bearing cable in real time and transmits it to the visual monitoring center and cloud platform; S3: the Beidou differential service system receives the position information transmitted by the Beidou positioning terminal, calculates the XY coordinates of each lifting point Z coordinate and transmit it to the control center; S4: the control center receives the XYZ coordinates of each hanging point and the cable tension data transmitted by the pin-type force sensor, processes the data, calculates the vertical displacement, height difference and lifting speed of each hanging point, and determines whether the cable tension is abnormal based on the cable tension data; S5: if the control center determines that the cable tension is normal, it sends instructions to the lifting winch based on the calculated vertical displacement, height difference and lifting speed of each hanging point, adjusts the action of each lifting winch, controls the lifting process, and ensures that the component is lifted smoothly into place; if the control center determines that the cable tension is abnormal, that is, the cable tension exceeds the set threshold or the difference between the tensions of any two cables exceeds the set threshold, the alarm device is triggered to alarm.

[0014] The principles and advantages of this solution are: This bridge girder hoisting system and positioning method achieves precise monitoring and dynamic control of the hoisting process by constructing a Beidou positioning + multi-sensor fusion + intelligent closed-loop control system. During system operation, the Beidou positioning terminal on the hanger collects the three-dimensional position information of each lifting point in real time. After calculation by the Beidou differential service system, it generates high-precision XYZ coordinates, providing the control center with a millimeter-level positioning reference. The pin-type force sensor installed at the spreader directly monitors the lifting cable tension, avoiding the friction error of traditional fixed-end installation. The lateral pressure sensor on each load-bearing cable synchronously collects cable tension data, forming a lifting cable-load-bearing cable dual-tension monitoring network. The control center fuses and processes multi-source data, calculates the vertical displacement, height difference, and lifting speed of the lifting point in real time, and determines abnormal cable tension status based on preset thresholds, such as whether a single cable exceeds the threshold or the cable tension difference exceeds the limit. When the data is normal, the control center sends coordinated control instructions to the hoisting winch to ensure that all lifting points are lifted synchronously; in the event of an abnormality, the alarm device is immediately triggered, and real-time data sharing and early warning are achieved through the visual monitoring center and cloud platform, forming a closed-loop control process of data collection - analysis and decision-making - execution and feedback, fundamentally solving the accuracy and safety problems of traditional lifting.

[0015] Compared with existing technologies, traditional encoder measurements are affected by factors such as wire rope elongation and slippage, with errors typically reaching 3 to 5 centimeters. This solution, however, uses Beidou differential positioning technology to achieve an accuracy improvement of 2mm for hoisting point positioning errors. For example, in the installation of steel trusses with a span of more than 500 meters, the main beam docking error is reduced from 15mm in traditional processes to less than 5mm, improving the installation accuracy of the bridge structure. In terms of hoisting point synchronization control, traditional multi-point hoisting relies on manual adjustment of the winch, with synchronization errors reaching more than 10 centimeters, which can easily cause the component to tilt. This solution uses a control center to calculate the parameters of each hoisting point in real time and automatically adjust the winch, controlling the height difference of the hoisting point to within 3mm. This completely solves the imbalance problem during hoisting in complex mountainous terrain. For example, the main beam horizontality deviation can still be maintained at less than 0.5° under wind speeds of 10m / s. In the field of cable tension monitoring, when traditional sensors are installed at the fixed end, friction causes cable tension measurement errors exceeding 8%, and real-time warnings are impossible. This solution moves the pin-type sensor to the spreader and combines it with a lateral pressure sensor to achieve dual cable tension monitoring, controlling the error to within 2%. When the tension of a load-bearing cable exceeds the threshold of 216.7KN or the cable tension difference exceeds 30KN, the system triggers an audible and visual alarm within 0.5 seconds. Compared with traditional manual inspections, this solution can detect hidden dangers in advance and successfully avoid main cable breakage accidents caused by uneven cable tension. In addition, this solution uses a cloud platform to store and analyze data throughout the entire process, improving construction efficiency and reducing labor costs, demonstrating significant technological leadership and engineering application value in the field of digital construction.

[0016] Furthermore, there are multiple Beidou positioning terminals, and one Beidou positioning terminal is set up for each lifting point to monitor the position of each lifting point. Each lifting point is equipped with a Beidou positioning terminal, which can realize full-dimensional and refined monitoring of the lifting point position. Through this one-to-one configuration method, the system can independently obtain the three-dimensional coordinate data of each lifting point in real time, accurately capture the subtle displacement changes of each lifting point during the lifting process, and avoid the overall state misjudgment problem caused by traditional single points or a small number of monitoring points. At the same time, the collaborative work of multiple terminals can build a distributed monitoring network, effectively improving data redundancy and reliability. Even if some terminals experience signal interference or failure, the overall controllability of the lifting posture can still be guaranteed through data from other terminals, thereby significantly improving the stability and safety of the lifting system, and providing solid guarantees for the smooth and accurate installation of the bridge main beam.

[0017] Furthermore, the connection between the pin-type force sensor and the sling is a detachable connection. The detachable connection between the pin-type force sensor and the sling improves the practicality and economy of the bridge main beam lifting system, and makes the installation process of the sensor more convenient and efficient. Construction personnel can quickly install it to the key stress-bearing parts of the sling, shortening the preliminary preparation time; during the maintenance stage, there is no need to carry out complicated disassembly of the sling, and the sensor can be removed separately for calibration and maintenance, effectively reducing equipment downtime and ensuring construction progress; when the sensor needs to be replaced due to long-term use or accidental damage, the detachable connection can quickly complete the replacement of the old with the new, reducing maintenance costs, and avoiding the failure of cable force monitoring due to sensor failure, ensuring the real-time and accuracy of cable force data during the lifting process, and comprehensively improving the reliability and service life of the lifting system.

[0018] Furthermore, it also includes a lateral pressure sensor, which is set on each load-bearing cable and is used to collect the cable force data of the load-bearing cable in real time, and transmit the data to the visual monitoring center and cloud platform in real time through the network. The lateral pressure sensor can collect the cable force of the load-bearing cable in real time, and its data is synchronously transmitted to the visual monitoring center and cloud platform through the network. On the one hand, the visual monitoring center can convert the data into intuitive charts to assist on-site personnel to quickly grasp the hoisting force status and promptly discover abnormal trends; on the other hand, the cloud platform can realize long-term storage and in-depth analysis of data, and predict the cable force change trend through historical data comparison and algorithm modeling, and warn of potential risks in advance. This multi-terminal collaborative data transmission mode not only ensures the real-time and integrity of the data, but also avoids the monitoring blind spots caused by the failure of a single sensor through data redundancy, forming a dual guarantee of "local monitoring + cloud analysis", providing all-round safety monitoring and decision support for the bridge main beam hoisting operation.

[0019] Furthermore, the visual monitoring center is used to display in real time the load-bearing cable force data collected by the lateral pressure sensor, the lifting point position data collected by the Beidou positioning terminal, and the lifting cable force data collected by the pin-type force sensor. Through the intuitive interface display, the operator can simultaneously grasp the real-time status of the load-bearing cable, lifting point, and lifting cable, and quickly identify abnormal fluctuations in the data of each key part, such as excessive displacement deviation of a certain lifting point or sudden change in cable force. At the same time, the centralized presentation of multi-source data facilitates cross-comparison analysis and timely discovery of correlation problems between data, such as the correspondence between cable force changes and lifting point displacements, thereby achieving dynamic and precise control of the lifting process. In addition, the visualization method lowers the threshold for data interpretation and helps personnel in different positions quickly obtain effective information.

[0020] Furthermore, the control center includes a data processing module and an instruction issuing module. The data processing module is used to process the received data, calculate the vertical displacement, height difference, lifting speed of each lifting point, and determine whether the cable tension is abnormal; the instruction issuing module is used to issue instructions to the hoisting winch according to the processing results of the data processing module. The data processing module parses real-time data, converts the original position and cable tension information into key parameters such as vertical displacement and height difference, and determines whether the cable tension is abnormal based on the preset threshold, providing a quantitative assessment of the lifting status; and the instruction issuing module adjusts the lifting speed and strength of each lifting point in time according to the processing results to ensure the synchronization and stability of the lifting action. This modular design not only makes the system logic clear and the functions clear, but also facilitates subsequent maintenance and upgrades. At the same time, through the data-driven intelligent decision-making mechanism, it effectively avoids the lag of manual intervention and greatly reduces operational risks.

[0021] Furthermore, in step S5, when the alarm device is triggered, the following steps are also included: the staff checks and adjusts the hoisting system based on the alarm information, and restarts the lifting process after the cable tension returns to normal. When the alarm device sends a signal, the staff can quickly locate potential problems in the hoisting system based on detailed alarm information, such as excessive cable tension and abnormal lifting point location, and specifically check for hidden dangers such as sensor failure, loose rigging, or uneven load distribution. Through manual inspection and necessary mechanical adjustments, the equipment can be restored to a safe operating state, avoiding serious consequences caused by faulty operations. Restarting the lifting process after the cable tension returns to normal can not only eliminate immediate risks, but also accumulate experience through this fault handling, optimize subsequent hoisting processes, and ensure the safety and reliability of the entire bridge main girder hoisting process.

[0022] Furthermore, the control center's method for processing data collected by the pin-type load cell and the Beidou system includes the following steps: 1. Temporal and spatial synchronization calibration steps The nanosecond timestamp provided by the BeiDou differential service system of the BeiDou system is used to align the asynchronous data of the pin-type load cell and the BeiDou positioning terminal in time and space. The specific formula is: in, For the The synchronization timestamp corresponding to the Beidou positioning moment, The first timestamp, For the pin sensor The most recent timestamp before and after, is the Beidou positioning frequency, is the cable force sampling frequency, and the missing data points after synchronization are filled by cubic spline interpolation; 2. Constructing a lifting point balance index based on Beidou 3D coordinates , the calculation formula is: ,in, For the Moment The vertical coordinates of the hanging points are collected by the Beidou positioning terminal. For the The average height of all hanging points at the moment, is the total number of hanging points, when When the lifting point is unbalanced, the warning is triggered; Construct the three-dimensional balance matrix B of the hanging point, and convert the vertical displacement of each hanging point obtained by Beidou positioning into and pin cable force Carry out coupling analysis, the specific formula is: Calculation of vertical imbalance: ,in is the number of hanging points, when When the balance warning is triggered; Calculation of cable force equilibrium coefficient: ， in is the average cable tension, When the cable force is balanced, the winch is started for synchronous adjustment; 3. Force-displacement correlation analysis model Based on Beidou positioning, the physical correlation equation is constructed based on the displacement gradient of the lifting point and the pin cable force to achieve real-time inversion of the stress state.

[0023] in, is the rate of change of cable force, is the vertical speed of the hanging point, , is the empirical coefficient, when the calculated cable force change rate is When , it is determined to be abnormal dynamic stress; Real-time early warning and collaborative control strategy Closed-loop control of suspension point balance and force is achieved through the following dual mechanisms: When the cable tension at a certain lifting point or When the cable tension difference between any two hanging points is and When the secondary frequency speed control is triggered; when and When the third level emergency stop command is triggered.

[0024] The control center of the above solution utilizes a multi-dimensional data processing and collaborative control strategy to address challenges such as data asynchrony, state imbalance, and abnormal force during the lifting process. The spatiotemporal synchronization calibration step utilizes the Beidou system's high-precision timestamps and uses cubic spline interpolation to eliminate data asynchrony errors between the pin-type force sensor and the Beidou positioning terminal, ensuring data consistency and accuracy. The lifting point balance index and three-dimensional balance matrix, constructed based on Beidou's three-dimensional coordinates, deeply couple the lifting point position with cable tension data, achieving precise early warning of imbalance conditions through quantitative indicators. The force-displacement correlation analysis model establishes a physical connection between displacement and cable tension, enabling real-time inversion of the lifting system's force state and proactively predicting risks. Furthermore, a triple early warning and control mechanism, based on risk levels, sequentially triggers audible and visual alarms, variable frequency speed regulation, and emergency shutdown, enhancing the intelligence and safety capabilities of the bridge main girder lifting system and ensuring stable and controllable lifting operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the present invention; Figure 2 It is a system flow chart of the present invention. DETAILED DESCRIPTION

[0026] Example 1, as attached Figure 1-2 As shown, a bridge main beam hoisting system includes: A hanger having a plurality of hanging points; A Beidou positioning terminal is provided at each of the hanging points, and is used to collect the position information of each hanging point in real time and transmit it to the Beidou differential service system; A pin-type load cell, mounted on a sling on the hanger, for monitoring the tension of the lifting rope and transmitting the data to a control center; The Beidou differential service system is used to receive the location information transmitted by the Beidou positioning terminal, calculate the XYZ coordinates of each hanging point, and transmit them to the control center; The control center is used to receive the XYZ coordinates of each lifting point transmitted by the Beidou differential service system and the cable force data transmitted by the pin-type load cell, process the data, calculate the vertical displacement, height difference and lifting speed of each lifting point, and determine whether the cable force is abnormal based on the cable force data. It then issues instructions to the hoisting winches and adjusts the operation of each hoisting winch. When the cable force exceeds the set threshold or the difference between any two cable forces exceeds the set threshold, the alarm device is triggered to sound an alarm. The alarm device is used to send out an alarm signal when the control center determines that the cable tension is abnormal.

[0027] A method for hoisting and positioning a bridge main beam comprises the following steps: S1: setting a Beidou positioning terminal on each lifting point of a hanger, installing a pin-type force sensor at the hanger of the hanger, and setting a lateral pressure sensor on each load-bearing cable; S2: during the lifting process, the Beidou positioning terminal collects the position information of each lifting point in real time and transmits it to the Beidou differential service system, the pin-type force sensor monitors the cable force of the lifting cable in real time and transmits the data to the control center, and the lateral pressure sensor collects the cable force data of the load-bearing cable in real time and transmits it to the visual monitoring center and cloud platform; S3: the Beidou differential service system receives the position information transmitted by the Beidou positioning terminal, calculates the XY coordinates of each lifting point Z coordinate and transmit it to the control center; S4: the control center receives the XYZ coordinates of each hanging point and the cable tension data transmitted by the pin-type force sensor, processes the data, calculates the vertical displacement, height difference and lifting speed of each hanging point, and determines whether the cable tension is abnormal based on the cable tension data; S5: if the control center determines that the cable tension is normal, it sends instructions to the lifting winch based on the calculated vertical displacement, height difference and lifting speed of each hanging point, adjusts the action of each lifting winch, controls the lifting process, and ensures that the component is lifted smoothly into place; if the control center determines that the cable tension is abnormal, that is, the cable tension exceeds the set threshold or the difference between the tensions of any two cables exceeds the set threshold, the alarm device is triggered to alarm.

[0028] This bridge girder hoisting system and positioning method achieves precise monitoring and dynamic control of the hoisting process by constructing a Beidou positioning + multi-sensor fusion + intelligent closed-loop control system. During system operation, the Beidou positioning terminal on the hanger collects the three-dimensional position information of each lifting point in real time. After calculation by the Beidou differential service system, it generates high-precision XYZ coordinates, providing the control center with a millimeter-level positioning reference. The pin-type force sensor installed at the spreader directly monitors the lifting cable tension, avoiding the friction error of traditional fixed-end installation. The lateral pressure sensor on each load-bearing cable synchronously collects cable tension data, forming a lifting cable-load-bearing cable dual-tension monitoring network. The control center fuses and processes multi-source data, calculates the vertical displacement, height difference, and lifting speed of the lifting point in real time, and determines abnormal cable tension status based on preset thresholds, such as whether a single cable exceeds the threshold or the cable tension difference exceeds the limit. When the data is normal, the control center sends coordinated control instructions to the hoisting winch to ensure that all lifting points are lifted synchronously; in the event of an abnormality, the alarm device is immediately triggered, and real-time data sharing and early warning are achieved through the visual monitoring center and cloud platform, forming a closed-loop control process of data collection - analysis and decision-making - execution and feedback, fundamentally solving the accuracy and safety problems of traditional lifting.

[0029] Compared with existing technologies, traditional encoder measurements are affected by factors such as wire rope elongation and slippage, with errors typically reaching 3 to 5 centimeters. This solution, however, uses Beidou differential positioning technology to achieve an accuracy improvement of 2mm for hoisting point positioning errors. For example, in the installation of steel trusses with a span of more than 500 meters, the main beam docking error is reduced from 15mm in traditional processes to less than 5mm, improving the installation accuracy of the bridge structure. In terms of hoisting point synchronization control, traditional multi-point hoisting relies on manual adjustment of the winch, with synchronization errors reaching more than 10 centimeters, which can easily cause the component to tilt. This solution uses a control center to calculate the parameters of each hoisting point in real time and automatically adjust the winch, controlling the height difference of the hoisting point to within 3mm. This completely solves the imbalance problem during hoisting in complex mountainous terrain. For example, the main beam horizontality deviation can still be maintained at less than 0.5° under wind speeds of 10m / s. In the field of cable tension monitoring, when traditional sensors are installed at the fixed end, friction causes cable tension measurement errors exceeding 8%, and real-time warnings are impossible. This solution moves the pin-type sensor to the spreader and combines it with a lateral pressure sensor to achieve dual cable tension monitoring, controlling the error to within 2%. When the tension of a load-bearing cable exceeds the threshold of 216.7KN or the cable tension difference exceeds 30KN, the system triggers an audible and visual alarm within 0.5 seconds. Compared with traditional manual inspections, this solution can detect hidden dangers in advance and successfully avoid main cable breakage accidents caused by uneven cable tension. In addition, this solution uses a cloud platform to store and analyze data throughout the entire process, improving construction efficiency and reducing labor costs, demonstrating significant technological leadership and engineering application value in the field of digital construction.

[0030] Furthermore, there are multiple Beidou positioning terminals, and one Beidou positioning terminal is set up for each lifting point to monitor the position of each lifting point. Each lifting point is equipped with a Beidou positioning terminal, which can realize full-dimensional and refined monitoring of the lifting point position. Through this one-to-one configuration method, the system can independently obtain the three-dimensional coordinate data of each lifting point in real time, accurately capture the subtle displacement changes of each lifting point during the lifting process, and avoid the overall state misjudgment problem caused by traditional single points or a small number of monitoring points. At the same time, the collaborative work of multiple terminals can build a distributed monitoring network, effectively improving data redundancy and reliability. Even if some terminals experience signal interference or failure, the overall controllability of the lifting posture can still be guaranteed through data from other terminals, thereby significantly improving the stability and safety of the lifting system, and providing solid guarantees for the smooth and accurate installation of the bridge main beam.

[0031] The connection method between the pin-type force sensor and the sling is a detachable connection. The detachable connection between the pin-type force sensor and the sling improves the practicality and economy of the bridge main beam lifting system, and makes the installation process of the sensor more convenient and efficient. Construction personnel can quickly install it to the key stress-bearing part of the sling, shortening the preliminary preparation time; during the maintenance stage, there is no need to carry out complicated disassembly of the sling, and the sensor can be removed separately for calibration and maintenance, effectively reducing equipment downtime and ensuring construction progress; when the sensor needs to be replaced due to long-term use or accidental damage, the detachable connection can quickly complete the replacement of the old with the new, reducing maintenance costs, and avoiding the failure of cable force monitoring due to sensor failure, ensuring the real-time and accuracy of cable force data during the lifting process, and comprehensively improving the reliability and service life of the lifting system.

[0032] It also includes a lateral pressure sensor, which is installed on each load-bearing cable and is used to collect the cable tension data of the load-bearing cable in real time. The data is transmitted to the visual monitoring center and cloud platform in real time via the network. The lateral pressure sensor can collect the cable tension of the load-bearing cable in real time, and its data is synchronously transmitted to the visual monitoring center and cloud platform via the network. On the one hand, the visual monitoring center can convert the data into intuitive charts to assist on-site personnel in quickly grasping the hoisting stress status and promptly discover abnormal trends. On the other hand, the cloud platform can realize long-term storage and in-depth analysis of data. Through historical data comparison and algorithm modeling, it can predict the trend of cable tension changes and provide early warning of potential risks. This multi-terminal collaborative data transmission mode not only ensures the real-time and integrity of the data, but also avoids the monitoring blind spots caused by the failure of a single sensor through data redundancy, forming a dual guarantee of "local monitoring + cloud analysis", providing comprehensive safety monitoring and decision support for the bridge main beam hoisting operation.

[0033] The visualization monitoring center is used to display in real time the load-bearing cable force data collected by the lateral pressure sensor, the suspension point position data collected by the Beidou positioning terminal, and the lifting cable force data collected by the pin-type force sensor. Through the intuitive interface display, the operator can simultaneously grasp the real-time status of the load-bearing cable, suspension point, and lifting cable, and quickly identify abnormal fluctuations in the data of each key part, such as excessive displacement deviation of a certain suspension point or sudden change in cable force. At the same time, the centralized presentation of multi-source data facilitates cross-comparison analysis and timely discovery of correlation problems between data, such as the correspondence between cable force changes and suspension point displacements, thereby achieving dynamic and precise control of the lifting process. In addition, the visualization method lowers the threshold for data interpretation and helps personnel in different positions quickly obtain effective information.

[0034] The control center includes a data processing module and an instruction issuing module. The data processing module is used to process the received data, calculate the vertical displacement, height difference, lifting speed of each lifting point, and determine whether the cable tension is abnormal; the instruction issuing module is used to issue instructions to the hoisting winch based on the processing results of the data processing module. The data processing module parses real-time data, converts the original position and cable tension information into key parameters such as vertical displacement and height difference, and determines whether the cable tension is abnormal based on preset thresholds, providing a quantitative assessment of the lifting status; and the instruction issuing module adjusts the lifting speed and force of each lifting point in a timely manner based on the processing results to ensure the synchronization and stability of the lifting action. This modular design not only makes the system logic clear and the functions clear, but also facilitates subsequent maintenance and upgrades. At the same time, through the data-driven intelligent decision-making mechanism, it effectively avoids the lag of manual intervention and greatly reduces operational risks.

[0035] In step S5, when the alarm device is triggered, the following steps are also included: the staff checks and adjusts the hoisting system according to the alarm information, and restarts the lifting process after the cable tension returns to normal. When the alarm device sends a signal, the staff can quickly locate potential problems in the hoisting system based on detailed alarm information, such as excessive cable tension and abnormal lifting point positions, and specifically check for hidden dangers such as sensor failure, loose rigging, or uneven load distribution. Through manual inspection and necessary mechanical adjustments, the equipment can be restored to a safe operating state to avoid serious consequences caused by faulty operations. Restarting the lifting process after the cable tension returns to normal can not only eliminate immediate risks, but also accumulate experience through this fault handling, optimize subsequent hoisting processes, and ensure the safety and reliability of the entire bridge main beam hoisting process.

[0036] The control center's method for processing data collected from the pin-type load cell and the Beidou system includes the following steps: 1. Temporal and spatial synchronization calibration steps The nanosecond timestamp provided by the BeiDou differential service system of the BeiDou system is used to align the asynchronous data of the pin-type load cell and the BeiDou positioning terminal in time and space. The specific formula is: in, For the The synchronization timestamp corresponding to the Beidou positioning moment, The first timestamp, For the pin sensor The most recent timestamp before and after, is the Beidou positioning frequency, is the cable force sampling frequency, and the missing data points after synchronization are filled by cubic spline interpolation; 2. Constructing a lifting point balance index based on Beidou 3D coordinates , the calculation formula is: ,in, For the Moment The vertical coordinates of the hanging points are collected by the Beidou positioning terminal. For the The average height of all hanging points at the moment, is the total number of hanging points, when When the lifting point is unbalanced, the warning is triggered; Construct the three-dimensional balance matrix B of the hanging point, and convert the vertical displacement of each hanging point obtained by Beidou positioning into and pin cable force Carry out coupling analysis, the specific formula is: Calculation of vertical imbalance: ,in is the number of hanging points, when When the balance warning is triggered; Calculation of cable force equilibrium coefficient: ， in is the average cable tension, When the cable force is balanced, the winch is started for synchronous adjustment; 3. Force-displacement correlation analysis model Based on Beidou positioning, the physical correlation equation is constructed based on the displacement gradient of the lifting point and the pin cable force to achieve real-time inversion of the stress state.

[0037] in, is the rate of change of cable force, is the vertical speed of the hanging point, , is the empirical coefficient, when the calculated cable force change rate is When , it is determined to be abnormal dynamic stress; Real-time early warning and collaborative control strategy Closed-loop control of suspension point balance and force is achieved through the following dual mechanisms: When the cable tension at a certain lifting point or When the cable tension difference between any two hanging points is and When the secondary frequency speed control is triggered; when When the third level emergency stop command is triggered.

[0038] The control center of the above solution utilizes a multi-dimensional data processing and collaborative control strategy to address challenges such as data asynchrony, state imbalance, and abnormal force during the lifting process. The spatiotemporal synchronization calibration step utilizes the Beidou system's high-precision timestamps and uses cubic spline interpolation to eliminate data asynchrony errors between the pin-type force sensor and the Beidou positioning terminal, ensuring data consistency and accuracy. The lifting point balance index and three-dimensional balance matrix, constructed based on Beidou's three-dimensional coordinates, deeply couple the lifting point position with cable tension data, achieving precise early warning of imbalance conditions through quantitative indicators. The force-displacement correlation analysis model establishes a physical connection between displacement and cable tension, enabling real-time inversion of the lifting system's force state and proactively predicting risks. Furthermore, a triple early warning and control mechanism, based on risk levels, sequentially triggers audible and visual alarms, variable frequency speed regulation, and emergency shutdown, enhancing the intelligence and safety capabilities of the bridge main girder lifting system and ensuring stable and controllable lifting operations. In actual use, 1. System equipment installation and implementation (1) Hanger and lifting point settings The hanger is designed and constructed based on the structural characteristics, weight distribution, and hoisting requirements of the bridge's main beam. Multiple lifting points are strategically planned and set on the hanger. The number, location, and spacing of these points are determined based on beam force calculations to ensure even load distribution during the hoisting process. For example, in a long-span steel truss bridge hoisting project, eight lifting points were evenly spaced on the hanger based on the weight and structural form of the main beam segments. Each point can theoretically support a load of approximately 100 tons.

[0039] (2) Beidou positioning terminal installation A Beidou positioning terminal is installed for each hanging point. During installation, ensure the terminal antenna is in an open, unobstructed location and securely fixed above the hanging point to ensure good reception of satellite signals. After installation, configure the terminal parameters and set the positioning frequency to 50Hz. This frequency enables the terminal to collect real-time 3D position information for each hanging point and stably transmit this data to the Beidou differential service system.

[0040] (3) Installation of pin-type force sensor Install the pin-type load cell at the hanger's spreader using a removable connection, either with high-strength bolts or a quick-release clip. Before installation, check that the sensor's range (0-2000kN) and accuracy (±2%) meet the requirements and perform calibration. During installation, ensure the sensor is accurately positioned at the load-bearing connection between the lifting cable and the spreader, enabling it to directly and accurately monitor the cable force and transmit the data to the control center at a 100Hz frequency.

[0041] (IV) Installation of lateral pressure sensor Lateral pressure sensors are installed at appropriate locations on each load-bearing cable. The sensor range is selected based on the cable's designed tension. During installation, ensure the sensor fits snugly against the cable to accurately collect real-time cable force data. Furthermore, the sensors are equipped with a network transmission module to transmit the collected data in real time to a visual monitoring center and cloud platform.

[0042] (V) Construction of control center and visual monitoring center A control center and visual monitoring center were established at appropriate locations on the construction site. The control center was equipped with high-performance servers, data processing workstations, and related software systems to receive and process lifting point coordinate data from the Beidou differential service system and cable force data from pin-type load cells. The visual monitoring center was equipped with a large-screen display system and data visualization software, which displayed load-bearing cable force data collected by lateral pressure sensors, lifting point position data collected by Beidou positioning terminals, and lifting cable force data collected by pin-type load cells in real-time in the form of intuitive charts and curves.

[0043] 2. Implementation of hoisting positioning method (1) Device initialization Before lifting the main girder, perform a comprehensive initialization of all installed sensors (Beidou positioning terminal, pin-type load cells, lateral pressure sensors) and systems (Beidou differential service system, control center, and visual monitoring center). Check the operating status of the sensors and data transmission capabilities to ensure that all equipment is operating normally and that parameter configurations are correct.

[0044] (2) Real-time data collection During the lifting process, each sensor operates at a set frequency. The Beidou positioning terminal collects real-time position information of each lifting point at a frequency of 50Hz and transmits it to the Beidou differential service system. The pin-type load cell monitors the lifting cable tension in real time at a frequency of 100Hz and transmits it to the control center. The lateral pressure sensor collects real-time load-bearing cable tension data and transmits it synchronously to the visual monitoring center and cloud platform.

[0045] (3) Data processing and analysis After receiving the data from the Beidou positioning terminal, the Beidou differential service system uses the nanosecond timestamp provided by it to calculate the XYZ coordinates of each hanging point through specific algorithms (such as the least squares method) and transmits it to the control center.

[0046] After receiving the coordinate and cable force data, the data processing module of the control center first performs time and space synchronization calibration. Temporal and spatial alignment of asynchronous data, For the The synchronization timestamp corresponding to the Beidou positioning moment, The first timestamp, For the pin sensor The nearest timestamp before and after is used to fill in the missing data points after synchronization through cubic spline interpolation.

[0047] Next, the vertical displacement, height difference, and lifting speed of each lifting point are calculated, and a lifting point balance index based on Beidou 3D coordinates is constructed: ,in, For the k Moment i The vertical coordinates of the hanging points are collected by the Beidou positioning terminal. For the The average height of all hanging points at the moment, is the total number of hanging points, when When the lifting point is unbalanced, the warning is triggered.

[0048] Construct the three-dimensional balance matrix B of the hanging point and calculate the vertical imbalance: ,in is the number of hanging points, when When the balance warning is triggered, the cable force equilibrium coefficient is calculated: ， in is the average cable tension, The cable force is balanced when the winch is started, otherwise the winch is started for synchronous adjustment.

[0049] The force-displacement correlation analysis model is constructed based on the Beidou positioning suspension point displacement gradient and the pin cable force:

[0050] in, is the rate of change of cable force, is the vertical speed of the hanging point, , is the empirical coefficient, when the calculated cable force change rate is When , it is determined to be abnormal dynamic force.

[0051] (IV) Intelligent control and alarm processing If the data processing module of the control center determines that the cable tension is normal, the instruction issuing module will issue precise instructions to the lifting winch based on the calculated vertical displacement, height difference and lifting speed of each lifting point, adjust the action of each winch, and control the synchronous lifting of each lifting point to ensure that the component is lifted smoothly into place, control the height difference of the lifting point within 3 mm, and the horizontal deviation of the main beam is less than 0.5°.

[0052] If the cable tension is abnormal, or When the cable tension difference between any two hanging points is and When the secondary frequency speed control is triggered; when and When the third level emergency stop command is triggered.

[0053] When the alarm device sounds, staff will quickly conduct a comprehensive inspection of the lifting system based on the alarm information displayed in the visual monitoring center, such as excessive cable tension and abnormal lifting point locations. They will check for sensor failures, loose rigging, uneven load distribution, and make targeted adjustments. Once the cable tension returns to normal and is confirmed to be correct, the lifting process will be restarted.

[0054] The above are only embodiments of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A bridge main beam hoisting system, characterized in that: include: A hanger having a plurality of hanging points; A Beidou positioning terminal is provided at each of the hanging points, and is used to collect the position information of each hanging point in real time and transmit it to the Beidou differential service system; A pin-type load cell, mounted on a sling on the hanger, for monitoring the tension of the lifting rope and transmitting the data to a control center; The Beidou differential service system is used to receive the location information transmitted by the Beidou positioning terminal, calculate the XYZ coordinates of each hanging point, and transmit them to the control center; The control center is used to receive the XYZ coordinates of each lifting point transmitted by the Beidou differential service system and the cable force data transmitted by the pin-type force sensor, process the data, calculate the vertical displacement, height difference and lifting speed of each lifting point, and determine whether the cable force is abnormal based on the cable force data. It then issues instructions to the hoisting winches and adjusts the operation of each hoisting winch. When the cable force exceeds the set threshold or the difference between the forces of any two cables exceeds the set threshold, the alarm device is triggered to sound an alarm; The alarm device is used to send out an alarm signal when the control center determines that the cable tension is abnormal.

2. A bridge main beam hoisting system according to claim 1, characterized in that: There are multiple Beidou positioning terminals, and each hanging point is correspondingly provided with a Beidou positioning terminal for monitoring the position of each hanging point.

3. A bridge main beam hoisting system according to claim 1, characterized in that: The connection between the pin-type force sensor and the sling is detachable, which is convenient for installation, maintenance and replacement.

4. The bridge main beam hoisting system according to claim 1, characterized in that: It also includes a lateral pressure sensor, which is set on each load-bearing cable to collect the cable force data of the load-bearing cable in real time and transmit the data in real time to the visual monitoring center and cloud platform through the network.

5. The bridge main beam hoisting system according to claim 1, characterized in that: The visual monitoring center is used to display in real time the load-bearing cable force data collected by the lateral pressure sensor, the lifting point position data collected by the Beidou positioning terminal, and the lifting cable force data collected by the pin-type force sensor.

6. A bridge main beam hoisting system according to claim 1, characterized in that: The control center includes a data processing module and an instruction issuing module. The data processing module is used to process the received data, calculate the vertical displacement, height difference, lifting speed of each lifting point, and determine whether the cable force is abnormal; the instruction issuing module is used to issue instructions to the lifting winch according to the processing results of the data processing module.

7. A bridge main beam hoisting and positioning method, using the bridge main beam hoisting system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: A Beidou positioning terminal is installed at each lifting point of the hanger, a pin-type force sensor is installed at the hanger's spreader, and a lateral pressure sensor is installed on each load-bearing cable; S2: During the lifting process, the Beidou positioning terminal collects the position information of each lifting point in real time and transmits it to the Beidou differential service system. The pin-type load cell monitors the cable tension of the lifting cable in real time and transmits the data to the control center. The lateral pressure sensor collects the cable tension data of the load-bearing cable in real time and transmits it to the visual monitoring center and cloud platform. S3: The Beidou differential service system receives the location information transmitted by the Beidou positioning terminal, calculates the XYZ coordinates of each lifting point and transmits it to the control center; S4: The control center receives the XYZ coordinates of each lifting point and the cable force data transmitted by the pin-type force sensor, processes the data, calculates the vertical displacement, height difference and lifting speed of each lifting point, and determines whether the cable force is abnormal based on the cable force data; S5: If the control center determines that the cable force is normal, it will send instructions to the lifting winch based on the calculated vertical displacement, height difference and lifting speed of each lifting point, adjust the action of each lifting winch, control the lifting process, and ensure that the component is lifted into place smoothly; if the control center determines that the cable force is abnormal, that is, the cable force exceeds the set threshold or the difference between the forces of any two cables exceeds the set threshold, the alarm device will be triggered to alarm.

8. The bridge main beam hoisting and positioning method according to claim 7, characterized in that: In step S5, when the alarm device is triggered to sound an alarm, the following steps are also included: the staff checks and adjusts the hoisting system according to the alarm information, and restarts the lifting process after the cable force returns to normal.

9. The bridge main beam hoisting and positioning method according to claim 7, characterized in that: The control center's method for processing data collected from the pin-type load cell and the Beidou system includes the following steps: Steps for space-time synchronization calibration The nanosecond timestamp provided by the BeiDou differential service system of the BeiDou system is used to align the asynchronous data of the pin-type load cell and the BeiDou positioning terminal in time and space. The specific formula is: in, For the The synchronization timestamp corresponding to the Beidou positioning moment, The first timestamp, For the pin sensor The most recent timestamp before and after, is the Beidou positioning frequency, is the cable force sampling frequency, and the missing data points after synchronization are filled by cubic spline interpolation; Constructing a lifting point balance index based on Beidou three-dimensional coordinates , the calculation formula is: in For the k Moment i The vertical coordinates of the hanging points are collected by the Beidou positioning terminal. For the The average height of all hanging points at the moment, is the total number of hanging points, when When the lifting point is unbalanced, the warning is triggered; Construct the three-dimensional balance matrix B of the hanging point, and convert the vertical displacement of each hanging point obtained by Beidou positioning into and pin cable force Carry out coupling analysis, the specific formula is: Calculation of vertical imbalance: , where n is the number of hanging points, when When the balance warning is triggered; Calculation of cable force equilibrium coefficient: , in is the average cable tension, When the cable force is balanced, the winch is started for synchronous adjustment; Force-displacement correlation analysis model Based on Beidou positioning, the physical correlation equation is constructed based on the displacement gradient of the lifting point and the pin cable force to achieve real-time inversion of the stress state. in, is the rate of change of cable force, is the vertical speed of the hanging point, ， is the empirical coefficient, when the calculated cable force change rate is When , it is determined to be abnormal dynamic stress; Real-time early warning and collaborative control strategy Closed-loop control of suspension point balance and force is achieved through the following dual mechanisms: When the cable tension at a certain lifting point or When the cable tension difference between any two hanging points is and When the secondary frequency speed control is triggered; when and When the third level emergency stop command is triggered.

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