Automatic deviation correction control method of tower crane torque limiter

Abstract

The application discloses an automatic deviation rectification control method of a tower crane torque limiter, relates to the technical field of automatic deviation rectification control of tower cranes, and is used for solving the problem of delayed response of the tower crane rectification, and the inability to timely avoid the dangerous operation state caused by wind load disturbance or attitude instability, calculating the wind speed influence of the tower crane by monitoring the wind load deviation angle and the environmental wind speed of the tower crane, collecting the no-load state data to determine whether the rectification mechanism is triggered, monitoring the inclination during the vertical lifting process after the triggering, and generating the structure influence characteristics, combining the wind speed influence coefficient to determine whether the safety limit is lowered, calculating the current torque by the torque limiter and comparing the current torque with the safety limit, determining whether the automatic deviation rectification control rule is enabled, when the automatic deviation rectification control rule is not enabled, detecting the load swing frequency in real time, collecting the rotary attitude deviation, combining the load swing frequency to update the safety limit, and determining whether the rectification rule is enabled again, so that the automation and real-time performance of the tower crane rectification are realized, and the rectification efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of automatic deviation control technology for tower cranes, and more specifically, to an automatic deviation control method for a tower crane torque limiter. Background Technology

[0002] With the acceleration of urbanization, the application of large lifting equipment such as tower cranes in the construction process is becoming increasingly widespread. The safety of tower cranes in high-altitude operations is directly related to the personal safety of construction workers and the safety of equipment on the construction site. Traditional tower crane operation mainly relies on manual operation and has a certain torque limit and wind speed alarm system. During tower crane operation, the set torque limiter continuously monitors whether the lifting torque exceeds the preset safety limit value. When the limit is exceeded, the system will automatically block further operation commands.

[0003] The existing technology has the following shortcomings:

[0004] Currently, although some tower crane control systems have introduced sensing devices such as torque limiters, wind speed sensors, and tilt sensors, most of these systems are based on static threshold early warning models and lack the ability to dynamically perceive the state of the tower crane throughout the entire cycle before, during, and after lifting. They cannot achieve comprehensive identification and control of key safety indicators such as wind speed disturbances, structural tilt, and load slewing frequency, resulting in delayed tower crane correction response and inability to avoid dangerous operating conditions caused by wind load disturbances or attitude instability in a timely manner. Therefore, an automatic correction control method for tower crane torque limiters is proposed.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide an automatic correction control method for a tower crane torque limiter, which solves the problems mentioned in the background art by employing multi-source sensor data fusion analysis and a dynamic safety limit update mechanism.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an automatic correction control method for a tower crane torque limiter, comprising the following steps: when the tower crane is not being lifted, monitoring the current ambient wind speed and the wind load offset influence angle of the tower crane and calculating the wind speed influence coefficient of the tower crane, collecting the no-load state data of the tower crane based on the tension sensor and determining whether the tower crane has triggered the correction mechanism;

[0008] Step S2: When the correction mechanism is triggered, the tilt sensor is used to monitor the vertical tilt of the tower crane during the vertical lifting process and generate the tower crane structure influence characteristics. Combined with the tower crane wind speed influence coefficient, it is determined whether to lower the tower crane safety limit.

[0009] Step S3: Obtain the current tower crane moment through the tower crane moment limiter, access the tower crane safety database to retrieve the tower crane safety limit and compare it with the current tower crane moment, then determine whether to enable the automatic correction control rule;

[0010] Step S4: When the automatic skew control rule is not enabled, the load swing frequency of the tower crane operation is detected in real time, the rotation attitude deviation of the tower crane operation is collected by the inertial sensor, and the tower crane safety limit is updated by combining the load swing frequency of the tower crane operation and then it is determined again whether to enable the automatic skew control rule.

[0011] In a preferred embodiment, in step S1, data is collected at fixed sampling intervals within a preset sampling time period to obtain continuous environmental wind speed data and environmental wind direction data, and the arithmetic mean is taken as the current environmental wind speed and current environmental wind direction.

[0012] Extract the target coordinates and starting point coordinates of the current lifting task, and calculate the slewing angle of this lifting task;

[0013] The difference between the current ambient wind direction and the slewing angle of this lifting task is taken as the wind load offset influence angle.

[0014] In a preferred embodiment, in step S1, the horizontal force of the tower crane under wind load is calculated based on the current ambient wind speed using a hydrodynamic wind force formula;

[0015] The effective offset force component generated by the wind load in the horizontal direction is calculated based on the wind load offset influence angle and the horizontal force of the tower crane under the wind load.

[0016] The rated torque of the tower crane is obtained, and the ratio of the effective offset force component generated by the wind load in the horizontal direction to the rated torque of the tower crane is used as the wind speed influence coefficient of the tower crane.

[0017] The hook force data is continuously collected within the preset sampling period, and the arithmetic mean is taken as the tower crane no-load state data.

[0018] If the tower crane's no-load status data is greater than the no-load force threshold, the correction mechanism will be triggered.

[0019] If the tower crane's no-load status data is less than or equal to the no-load stress threshold, monitoring will continue.

[0020] In a preferred embodiment, in step S2, when the correction mechanism is triggered, the vertical tilt of the tower crane during the vertical lifting process is collected in real time and filtered using a first-order exponential smoothing algorithm;

[0021] Based on the filtered vertical tilt, the influence characteristic value of the tower crane structure is calculated;

[0022] The tower crane wind speed influence coefficient and the tower crane structural influence characteristic value are used as input variables to input the logistic regression judgment model to calculate the probability value of lowering the tower crane safety limit;

[0023] If the probability value of lowering the safety limit of the tower crane is greater than or equal to the preset judgment probability threshold, then the safety limit of the tower crane will be lowered.

[0024] If the probability value of lowering the safety limit of the tower crane is less than the judgment probability threshold, then the safety limit of the tower crane will not be lowered.

[0025] When adjusting the safety limit of the tower crane, the rated torque of the tower crane is updated based on the wind speed influence coefficient and the structural influence characteristic value of the tower crane to obtain the adjusted safety limit of the tower crane and store it in the tower crane safety database.

[0026] In a preferred embodiment, in step S3, the torque of the tower crane under the current operating state is obtained in real time by the tower crane torque limiter as the current tower crane torque;

[0027] Search the tower crane safety database to find the tower crane safety limits that match the current tower crane model;

[0028] Compare the tower crane's safety limits with the current tower crane torque to determine whether to activate the automatic deviation correction control rule:

[0029] If the current tower crane torque exceeds the tower crane's safety limit, the automatic correction control rule will be activated.

[0030] Conversely, the automatic correction control rules will not be enabled.

[0031] In a preferred embodiment, in step S4, when the automatic correction control rule is not enabled, the load swing frequency of the tower crane operation is detected in real time.

[0032] The reciprocating motion trajectory of the load in the horizontal direction is collected by a high-precision displacement sensor, forming a displacement sequence signal that varies with time.

[0033] The frequency domain function is obtained by performing spectral analysis on the displacement sequence signal using Fourier transform. The magnitude of the frequency domain function is calculated as the amplitude, and the frequency corresponding to the maximum amplitude is taken as the load swing frequency.

[0034] The inertial sensor collects angular velocity and linear acceleration in different directions in real time.

[0035] In a preferred embodiment, in step S4, the three-dimensional attitude angles are calculated using angular velocity and linear acceleration. The three-dimensional attitude angles include roll angle, pitch angle and yaw angle.

[0036] Calculate roll and pitch angles using linear acceleration;

[0037] The yaw angle is calculated by integrating the angular velocity.

[0038] When the tower crane is stationary, the initial roll angle, pitch angle, and yaw angle are collected by inertial sensors.

[0039] In a preferred embodiment, in step S4, the turning attitude offset is calculated by subtracting the current roll angle, pitch angle, and yaw angle from the initial roll angle, pitch angle, and yaw angle. ,in, This is the difference between the current roll angle and the initial roll angle. This is the difference between the current pitch angle and the initial pitch angle. This is the difference between the current yaw angle and the initial yaw angle. This represents the rotation attitude offset.

[0040] In a preferred embodiment, in step S4, the tower crane safety limit is updated by combining the rotational attitude offset and the load swing frequency.

[0041] Compare the current tower crane torque with the updated tower crane safety limits to determine whether to enable automatic deviation correction control rules:

[0042] If the current tower crane torque is greater than the updated tower crane safety limit, then the automatic correction control rule will be activated.

[0043] Conversely, the automatic correction control rules will not be enabled.

[0044] The technical effects and advantages of this invention are as follows:

[0045] This invention assesses the impact of wind speed on the tower crane by monitoring the wind load offset angle and calculating the current environmental wind speed. It collects data on the tower crane's no-load status to determine if a correction mechanism has been triggered. If the correction mechanism is triggered, it monitors the vertical tilt of the tower crane during vertical lifting and generates the tower crane's result impact characteristics. Combined with the tower crane's wind speed impact coefficient, it determines whether to lower the tower crane's safety limit. It calculates the current tower crane torque using a torque limiter, calls the tower crane's safety limit, and compares it with the current tower crane torque to determine whether to enable automatic correction control rules. If automatic correction control rules are not enabled, it monitors the load swing frequency of the tower crane in real time, collects the tower crane's rotational attitude offset, updates the tower crane's safety limit based on the load swing frequency, and re-determines whether to enable automatic correction control rules. This achieves automatic real-time tower crane correction, improves correction efficiency, and enables high-precision tower crane attitude correction. Attached Figure Description

[0046] Figure 1 This is a flowchart illustrating the implementation of an automatic correction control method for a tower crane torque limiter according to the present invention.

[0047] Figure 2 This is a schematic diagram illustrating the steps of an automatic correction control method for a tower crane torque limiter according to the present invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] This invention assesses the impact of wind speed on the tower crane by monitoring the wind load offset angle and calculating the current environmental wind speed. It collects data on the tower crane's no-load status to determine if a correction mechanism has been triggered. If the correction mechanism is triggered, it monitors the vertical tilt of the tower crane during vertical lifting and generates the tower crane's result impact characteristics. Combined with the tower crane's wind speed impact coefficient, it determines whether to lower the tower crane's safety limit. It calculates the current tower crane torque using a torque limiter, calls the tower crane's safety limit, and compares it with the current tower crane torque to determine whether to enable automatic correction control rules. If automatic correction control rules are not enabled, it monitors the load swing frequency of the tower crane in real time, collects the tower crane's rotational attitude offset, updates the tower crane's safety limit based on the load swing frequency, and re-determines whether to enable automatic correction control rules. This achieves automatic real-time tower crane correction, improving correction efficiency.

[0050] Example 1: An automatic correction control method for a tower crane torque limiter, such as... Figures 1 to 2As shown, it includes the following steps:

[0051] Step S1: When the tower crane is not lifting, monitor the current ambient wind speed and the wind load offset angle of the tower crane and calculate the wind speed influence coefficient of the tower crane. Collect the no-load state data of the tower crane based on the tension sensor and determine whether the tower crane triggers the correction mechanism.

[0052] Step S2: When the correction mechanism is triggered, the tilt sensor is used to monitor the vertical tilt of the tower crane during the vertical lifting process and generate the tower crane structure influence characteristics. Combined with the tower crane wind speed influence coefficient, it is determined whether to lower the tower crane safety limit.

[0053] Step S3: Obtain the current tower crane moment through the tower crane moment limiter, access the tower crane safety database to retrieve the tower crane safety limit and compare it with the current tower crane moment, then determine whether to enable the automatic correction control rule;

[0054] Step S4: When the automatic skew control rule is not enabled, the load swing frequency of the tower crane operation is detected in real time, the rotation attitude deviation of the tower crane operation is collected by the inertial sensor, and the tower crane safety limit is updated by combining the load swing frequency of the tower crane operation and then it is determined again whether to enable the automatic skew control rule.

[0055] The specific implementation is as follows:

[0056] In step S1, when the tower crane is in an unlifted state, wind speed sensors installed at the top of the tower crane and the end of the boom collect real-time data on the current ambient wind speed and direction within a preset sampling time period. Data is collected at fixed sampling intervals to obtain continuous environmental wind speed and direction data. After data collection is completed, the arithmetic mean of the collected environmental wind speed and direction data is taken as the current environmental wind speed and current environmental wind direction, respectively.

[0057] The built-in task parameter library is used to extract the target coordinates and starting point coordinates of the current lifting task, and the slewing angle of this lifting task is calculated. The specific calculation formula is as follows:

[0058] ;

[0059] in, The slewing angle for this lifting operation. The target coordinates for the current lifting task. These are the coordinates of the lifting start point.

[0060] The difference between the current wind direction and the slewing angle of this lifting task is taken as the wind load offset influence angle. The wind load offset influence angle reflects the degree of disturbance torque exerted by the wind load on the tower crane structure and its load, and serves as a basic indicator for judging the risk of wind load interference in subsequent data calculations.

[0061] Based on the current ambient wind speed and wind load offset influence angle, the wind speed influence coefficient of the tower crane is calculated. First, based on the current ambient wind speed, the horizontal force of the tower crane under wind load is calculated using the hydrodynamic wind force formula. The specific calculation formula is as follows:

[0062] ;

[0063] in, This refers to the horizontal force exerted on the tower crane under wind load. The value is the air density, taken under standard atmospheric conditions. ; The windward projected area of ​​the tower crane is determined based on the tower crane design drawings, including the effective area of ​​the tower body, boom, and auxiliary structures. The drag coefficient is a dimensionless parameter, and its value range is determined according to the structural shape. In this embodiment, the tower crane is a frame structure, and the drag coefficient is 1.4. Given the current ambient wind speed, The total wind load acting on the structure is obtained by multiplying the change in wind energy density by the projected area and drag coefficient.

[0064] The effective offset force component generated by wind load in the horizontal direction is calculated based on the wind load offset influence angle. The calculation formula is as follows:

[0065] ;

[0066] in, This represents the effective offset force component generated by wind load in the horizontal direction; The angle of influence of wind load offset.

[0067] Retrieve the tower crane's rated torque from the tower crane safety database. The tower crane's rated torque is the safety limit set by the tower crane manufacturer at the time of manufacture. The ratio of the effective offset force component generated by the wind load in the horizontal direction to the tower crane's rated torque is used as the tower crane's wind speed influence coefficient. When the tower crane's wind speed influence coefficient approaches or exceeds 1, it means that the effect of the wind load on the tower crane structure is close to or reaches the tower crane's rated torque.

[0068] After calculating the wind speed influence coefficient of the tower crane, a tension sensor installed at the tower crane hook is used for sampling at a preset period. The system continuously collects hook force data and takes the arithmetic mean as the tower crane's no-load state data.

[0069] The tower crane's no-load status data is compared with the preset no-load stress threshold. If the tower crane's no-load status data is greater than the no-load stress threshold, the correction mechanism is triggered; if the tower crane's no-load status data is less than or equal to the no-load stress threshold, monitoring continues.

[0070] It should be noted that the wind speed sensor is an environmental monitoring unit installed at the top of the tower crane structure. It is used to detect the ambient wind speed and direction in the tower crane's operating area in real time. The output signal is in digital format and can be directly used for subsequent calculations after A / D conversion. The operation task parameter library is a non-volatile storage space used to store the path information, target coordinates, and operation plan data related to the current lifting operation. The no-load force threshold is a mechanical parameter used to determine whether the tower crane is in a no-load state. It is set by the tower crane manufacturer during the tower crane's factory calibration stage based on the tower crane's hook mass, sling weight, and residual tension after wind load disturbance. It will not be elaborated here. The tower crane safety database is a data platform for storing and managing tower crane safety limit parameters, recording the rated torque of different tower crane models.

[0071] In step S2, when the tower crane triggers the correction mechanism, the vertical tilt angle generated by the tower crane during vertical lifting is collected in real time by tilt sensors installed on the tower crane body and slewing mechanism. The data is then processed by low-pass filtering to reduce high-frequency fluctuations caused by environmental noise, mechanical vibration, and other interference during the tilt sensor sampling process, thereby obtaining a more stable vertical tilt angle of the tower crane. The filtering function adopts a first-order exponential smoothing algorithm.

[0072] ;

[0073] in, The smoothed vertical inclination is calculated at time t. In time The original vertical tilt angle is constantly collected by the tilt sensor. For the previous time step The smoothed vertical tilt calculated at each moment This is a smoothing coefficient, with a range of values. , The smaller the value, the higher the weight of historical data, and the more stable the smoothed value.

[0074] Based on the filtered vertical tilt, the characteristic value of the tower crane structure's influence is calculated, and the calculation formula is as follows:

[0075] ;

[0076] in, The characteristic value of the tower crane structure. This represents the vertical tilt after filtering. This is the weighting coefficient for the vertical inclination. The weighting coefficient for the rate of change of vertical inclination. The rate of change of vertical tilt is obtained by the difference between adjacent time points:

[0077] ;

[0078] in, This represents the time difference between adjacent moments.

[0079] The tower crane wind speed influence coefficient is used, combined with the tower crane structural influence characteristic value, as input variables into the logistic regression judgment model to calculate the probability value of lowering the tower crane safety limit. The calculation formula is as follows:

[0080] ;

[0081] in, To lower the probability value of the tower crane's safety limit, and is the model weight parameter, and b is the bias term.

[0082] The probability value of lowering the tower crane's safety limit is compared with a preset judgment probability threshold to determine whether to lower the tower crane's safety limit. If the probability value of lowering the tower crane's safety limit is greater than or equal to the judgment probability threshold, then the tower crane's safety limit is lowered; if the probability value of lowering the tower crane's safety limit is less than the judgment probability threshold, then the tower crane's safety limit is not lowered.

[0083] When adjusting the safety limit of a tower crane, the rated moment of the tower crane is updated based on the wind speed influence coefficient and the structural influence characteristic value of the tower crane to obtain the adjusted safety limit of the tower crane. The specific calculation formula is as follows:

[0084] ;

[0085] in, The adjusted safety limits for tower cranes; The rated torque of the tower crane; This is a correction factor for the wind speed influence coefficient of tower cranes, with a range of values. ; The value range is the correction coefficient for the structural influence characteristics of the tower crane. .

[0086] Once the adjusted tower crane safety limit calculation is completed, it is stored in the tower crane safety database for subsequent calculations.

[0087] It should be noted that the tilt sensor is a measuring device used to detect the tilt angle of the measured structure relative to the horizontal plane, and can output the spatial attitude change information of the structure in real time; low-pass filtering is a signal processing method used to suppress high-frequency noise components and retain low-frequency information in the input signal to achieve smoothing of the measurement data; the first-order exponential smoothing algorithm is a recursive data smoothing method that generates a smooth output with moderate response speed and anti-interference ability by weighted averaging of the current sampled value and historical smoothed value; the logistic regression decision model is a mathematical model used for binary classification decision-making. It predicts the probability of the occurrence of the target event by performing nonlinear mapping on the linear combination result of the input features. In this embodiment, it is used to jointly determine the tower crane wind speed influence coefficient and the tower crane structure influence characteristic value, thereby determining whether to automatically lower the tower crane safety limit value.

[0088] In step S3, the torque of the tower crane under the current operating state is obtained in real time through the tower crane torque limiter as the current tower crane torque;

[0089] By accessing the tower crane safety database to retrieve the tower crane safety limits that match the current tower crane model, and comparing the tower crane safety limits with the current tower crane torque, it is determined whether to enable the automatic correction control rules.

[0090] It needs to be explained that the tower crane safety database is a data platform for storing and managing tower crane safety limit parameters. It records the rated torque of tower cranes corresponding to different models of tower cranes. If there is no dynamic data to adjust the rated torque of the tower crane, the rated torque of the tower crane will be used as the tower crane safety limit. If there is an updated rated torque of the tower crane, the updated rated torque of the tower crane will be used as the tower crane safety limit.

[0091] If the current tower crane torque exceeds the tower crane's safety limit, the automatic correction control rule will be activated.

[0092] Conversely, automatic correction control rules will not be enabled.

[0093] Automatic deviation control rules refer to the control strategies and execution mechanisms that are automatically triggered when the system detects excessive torque or other critical safety risk indicators during tower crane operation. These mechanisms dynamically adjust the operation status to ensure that the tower crane operates within a safe range.

[0094] The automatic correction control rules include: when the current tower crane torque exceeds the tower crane's safety limit, limiting the tower crane's slewing amplitude, reducing the boom's operating speed, and triggering an alarm command to prompt the operator to intervene.

[0095] By acquiring the current tower crane torque in real time and dynamically comparing it with the tower crane safety limits in the safety database, it is possible to accurately determine whether the tower crane is within the safe operating range, promptly activate automatic correction control rules, effectively prevent structural risks caused by tower crane torque exceeding limits, and ensure the safety and stability of tower crane operations.

[0096] It should be noted that the tower crane torque limiter is used to monitor the torque changes of the tower crane in real time during operation. The tower crane torque limiter has a built-in sensor module and a torque calculation module. The sensor module obtains the load weight and load position, and the torque calculation module multiplies the load weight and load position to obtain the current tower crane torque.

[0097] In step S4, when the automatic correction control rule is not enabled, the load swing frequency of the tower crane operation is detected in real time;

[0098] The load swing frequency refers to the periodic frequency of the load swinging freely around the lifting point under the action of gravity. By installing a high-precision displacement sensor on the hook to collect the reciprocating motion trajectory of the load in the horizontal direction, a displacement sequence signal that varies with time is formed. The frequency domain function is obtained by performing spectrum analysis on the displacement sequence signal through Fourier transform.

[0099] The frequency domain function is represented in complex form, reflecting the amplitude and phase information of different frequency components in the original signal. The magnitude of the frequency domain function is calculated as the amplitude, and the frequency corresponding to the maximum amplitude is taken as the load swing frequency.

[0100] An inertial sensor is fixedly installed on the slewing platform of a tower crane to collect angular velocity and linear acceleration in different directions in real time.

[0101] The three-dimensional attitude angles are calculated by angular velocity and linear acceleration. The three-dimensional attitude angles include roll angle, pitch angle and yaw angle, which reflect whether the structure tilts, sways or rotates abnormally during tower crane operation.

[0102] When a tower crane tilts to the left or right, the angle at which the tower crane structure rotates around the front-back direction is called the roll angle; when a tower crane pitches forward or backward, the angle at which the tower crane structure rotates around the left or right direction is called the pitch angle; when a tower crane rotates horizontally, the angle at which the tower crane structure rotates around the vertical direction is called the yaw angle.

[0103] Calculate the roll angle using linear acceleration: ,in, It is a linear acceleration that rotates about the left and right directions. It is a linear acceleration about the vertical direction. For roll angle;

[0104] Calculate pitch angle using linear acceleration: ,in, It is a linear acceleration of rotation about the forward and backward direction. It is a linear acceleration that rotates about the left and right directions. It is a linear acceleration about the vertical direction. The pitch angle;

[0105] The yaw angle is calculated by integrating the angular velocity: ,in, For tower cranes at all times The angular velocity of rotation about the vertical direction, where t is the current time and 0 is the initial time. Yaw angle;

[0106] The slewing attitude offset of tower crane operation refers to the angular deviation of the tower crane's spatial attitude relative to its initial static state when the tower crane structure is dynamically changing during operation. It reflects whether the tower crane has experienced structural tilting, dynamic swaying, or abnormal rotation during operation.

[0107] The turning attitude offset is calculated by subtracting the current roll, pitch, and yaw angles from the initial roll, pitch, and yaw angles. ,in, This is the difference between the current roll angle and the initial roll angle. This is the difference between the current pitch angle and the initial pitch angle. This is the difference between the current yaw angle and the initial yaw angle. This represents the rotation attitude offset.

[0108] When the tower crane is stationary, the initial roll angle, pitch angle, and yaw angle are collected by inertial sensors as reference benchmarks for the rotation attitude deviation during operation.

[0109] The safety limits of the tower crane are updated by combining the rotational attitude deviation and the load swing frequency. ,in, This represents the rotation attitude offset. For the load swing frequency, , For preset calibration coefficients, The tower crane safety limits were retrieved from the tower crane safety database. The updated safety limits for tower cranes;

[0110] Compare the current tower crane torque with the updated tower crane safety limits to determine whether to enable automatic deviation correction control rules:

[0111] If the current tower crane torque is greater than the updated tower crane safety limit, then the automatic correction control rule will be activated.

[0112] Conversely, the automatic correction control rules will not be enabled.

[0113] Without triggering the automatic correction control rules, the tower crane safety limits are updated in real time by monitoring the load swing frequency and rotation attitude deviation, thereby achieving refined management of the tower crane's operating status, improving the adaptability and accuracy of the tower crane's safety limits, and further reducing potential safety hazards.

[0114] It should be noted that a high-precision displacement sensor is a precision sensing device used to measure changes in the position of an object. It is used to collect real-time data on the horizontal swing displacement of a suspended load, forming a displacement sequence signal that varies over time. Fourier transform is a method used to convert a time-domain signal that varies over time into a frequency-domain signal that varies over frequency. It is used to transform the displacement sequence signal into a frequency domain function, which is a complex number representing the contribution of different frequency components to the original signal. The amplitude is obtained by calculating the modulus of the complex number, and the frequency corresponding to the largest amplitude is taken as the load swing frequency. An inertial sensor is also included. Preset calibration coefficients are used to reflect the influence of rotational attitude offset and load swing frequency on the safety limits of the tower crane. These parameters are calibrated by professionals through experiments and on-site data.

[0115] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0116] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0117] In this document, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0118] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0119] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications to these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An automatic correction control method for a tower crane torque limiter, characterized in that: Includes the following steps: Step S1: When the tower crane is not lifting, monitor the current ambient wind speed and the wind load offset angle of the tower crane and calculate the wind speed influence coefficient of the tower crane. Collect the no-load state data of the tower crane based on the tension sensor and determine whether the tower crane triggers the correction mechanism. In step S1, data is collected at fixed sampling intervals within a preset sampling time period to obtain continuous environmental wind speed and environmental wind direction data, and the arithmetic mean is taken as the current environmental wind speed and current environmental wind direction. Extract the target coordinates and starting point coordinates of the current lifting task, and calculate the slewing angle of this lifting task; The difference between the current ambient wind direction and the slewing angle of this lifting task is taken as the wind load offset influence angle; In step S1, the horizontal force of the tower crane under wind load is calculated using the hydrodynamic wind force formula based on the current ambient wind speed; The effective offset force component generated by the wind load in the horizontal direction is calculated based on the wind load offset influence angle and the horizontal force of the tower crane under the wind load. The rated torque of the tower crane is obtained, and the ratio of the effective offset force component generated by the wind load in the horizontal direction to the rated torque of the tower crane is used as the wind speed influence coefficient of the tower crane. The hook force data is continuously collected within the preset sampling period, and the arithmetic mean is taken as the tower crane no-load state data. If the tower crane's no-load status data is greater than the no-load force threshold, the correction mechanism will be triggered. If the tower crane's no-load status data is less than or equal to the no-load stress threshold, monitoring will continue. Step S2: When the correction mechanism is triggered, the tilt sensor is used to monitor the vertical tilt of the tower crane during the vertical lifting process and generate the tower crane structure influence characteristics. Combined with the tower crane wind speed influence coefficient, it is determined whether to lower the tower crane safety limit. In step S2, when the correction mechanism is triggered, the vertical tilt of the tower crane during the vertical lifting process is collected in real time and filtered using a first-order exponential smoothing algorithm. Based on the filtered vertical tilt, the influence characteristic value of the tower crane structure is calculated; The tower crane wind speed influence coefficient and the tower crane structural influence characteristic value are used as input variables to input the logistic regression judgment model to calculate the probability value of lowering the tower crane safety limit; If the probability value of lowering the safety limit of the tower crane is greater than or equal to the preset judgment probability threshold, then the safety limit of the tower crane will be lowered. If the probability value of lowering the safety limit of the tower crane is less than the judgment probability threshold, then the safety limit of the tower crane will not be lowered. When adjusting the safety limit of the tower crane, the rated torque of the tower crane is updated based on the wind speed influence coefficient and the structural influence characteristic value of the tower crane to obtain the adjusted safety limit of the tower crane and store it in the tower crane safety database. Step S3: Obtain the current tower crane moment through the tower crane moment limiter, access the tower crane safety database to retrieve the tower crane safety limit and compare it with the current tower crane moment, then determine whether to enable the automatic correction control rule; Step S4: When the automatic skew control rule is not enabled, the load swing frequency of the tower crane operation is detected in real time, the rotation attitude deviation of the tower crane operation is collected by the inertial sensor, and the tower crane safety limit is updated by combining the load swing frequency of the tower crane operation and then it is determined again whether to enable the automatic skew control rule.

2. The automatic correction control method for a tower crane torque limiter according to claim 1, characterized in that: In step S3, the torque of the tower crane under the current operating state is obtained in real time through the tower crane torque limiter as the current tower crane torque; Search the tower crane safety database to find the tower crane safety limits that match the current tower crane model; Compare the tower crane's safety limits with the current tower crane torque to determine whether to activate the automatic deviation correction control rule: If the current tower crane torque exceeds the tower crane's safety limit, the automatic correction control rule will be activated. Conversely, the automatic correction control rules will not be enabled.

3. The automatic correction control method for a tower crane torque limiter according to claim 1, characterized in that: In step S4, when the automatic correction control rule is not enabled, the load swing frequency of the tower crane operation is detected in real time; The reciprocating motion trajectory of the load in the horizontal direction is collected by a high-precision displacement sensor, forming a displacement sequence signal that varies with time. The frequency domain function is obtained by performing spectral analysis on the displacement sequence signal using Fourier transform. The magnitude of the frequency domain function is calculated as the amplitude, and the frequency corresponding to the maximum amplitude is taken as the load swing frequency. The inertial sensor collects angular velocity and linear acceleration in different directions in real time.

4. The automatic correction control method for a tower crane torque limiter according to claim 3, characterized in that: In step S4, the three-dimensional attitude angles are calculated using angular velocity and linear acceleration. The three-dimensional attitude angles include roll angle, pitch angle, and yaw angle. Calculate roll and pitch angles using linear acceleration; The yaw angle is calculated by integrating the angular velocity. When the tower crane is stationary, the initial roll angle, pitch angle, and yaw angle are collected by inertial sensors.

5. The automatic correction control method for a tower crane torque limiter according to claim 4, characterized in that: In step S4, the turning attitude offset is calculated by subtracting the current roll angle, pitch angle, and yaw angle from the initial roll angle, pitch angle, and yaw angle. ,in, This is the difference between the current roll angle and the initial roll angle. This is the difference between the current pitch angle and the initial pitch angle. This is the difference between the current yaw angle and the initial yaw angle. This represents the rotation attitude offset.

6. The automatic correction control method for a tower crane torque limiter according to claim 5, characterized in that: In step S4, the safety limit of the tower crane is updated by combining the rotational attitude offset and the load swing frequency. Compare the current tower crane torque with the updated tower crane safety limits to determine whether to enable automatic deviation correction control rules: If the current tower crane torque is greater than the updated tower crane safety limit, then the automatic correction control rule will be activated. Conversely, the automatic correction control rules will not be enabled.

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