A kind of anti-overturning safety monitoring system for pole derrick rotary support mechanism

Abstract

The present application relates to the technical field of anti-overturning safety monitoring, and discloses an anti-overturning safety monitoring system for a rotary support mechanism of a holding pole, which realizes real-time monitoring of the working state of the holding pole by collecting attitude parameters, load parameters, motion parameters and environmental wind parameters, and inputting nominal anti-overturning stiffness and overturning torque limit. The external overturning torque, its peak value and time change rate are calculated according to the load, motion and wind information; the equivalent time delay and the corresponding angle frequency of the right half plane zero point are obtained by frequency domain identification, the beat frequency is calculated in combination with the working condition parameters, the representative frequency of the main energy area of the gust is determined by performing spectrum analysis on the wind speed signal, and the frequency band overlap index is obtained by comparison. The equivalent torque gap is obtained according to the equivalent time delay, the structure parameters and the change rate of the external overturning torque, the peak value of the external overturning torque is corrected to obtain a corrected peak value, and then the safety is determined by using the corrected peak value, the overturning torque limit and the frequency band overlap index.

Description

Technical Field

[0001] This invention relates to the field of anti-tipping safety monitoring technology, and more specifically, to an anti-tipping safety monitoring system for a pole slewing support mechanism. Background Technology

[0002] In power transmission line construction, the erection of ultra-high voltage (UHV) towers is currently the main task. UHV towers are generally four-sided pyramidal towers assembled from steel pipes. When erecting UHV towers, a ground foundation and tower base must first be built on the ground. Then, the tower components are gradually erected upwards. When the UHV tower reaches a certain height, a hoisting gantry is needed as an auxiliary lifting tool to safely transport the components to that height. The hoisting gantry consists of the gantry body, a slewing platform, and a boom. The boom is rotatably connected to the gantry column via the slewing platform. Due to the high construction height of the gantry, it is prone to overturning accidents due to stress imbalance, improper operation, and external factors (such as strong winds). The slewing platform is the weakest component of the gantry and is extremely susceptible to overturning, leading to significant safety risks.

[0003] The slewing boom mechanism is a temporary lifting device widely used in the erection of power transmission towers and high-altitude hoisting operations. It typically includes a double-arm slewing boom, a prefabricated base, a slewing bearing, a reduction drive, and an electric slewing unit. This type of equipment achieves precise positioning of large components through independent luffing of the two arms and the slewing bearing, offering flexibility and stability in high-altitude hoisting environments. However, due to the complex wind load environment and asymmetrical stress state during operation, its safety monitoring requirements are far higher than those of general lifting machinery. Especially in windy areas or mountainous construction, gusts, asynchronous luffing of the two arms, and slewing transmission clearances combine to cause nonlinear and time-varying changes in the equipment's posture. Traditional monitoring methods often only rely on tilt angle, tension, or torque thresholds for alarms, failing to reflect the true safety status of the device in short-term transient phases.

[0004] In practical engineering, when a slewing support mechanism is subjected to sudden gusts of wind or asynchronous lifting of the booms, the external overturning moment rises rapidly within a very short time. Due to the mechanical clearance between the gear ring drive and the reducer, a slight slippage and time lag occur between the slewing bearing and the base in the initial stage of the load change. This lag causes the measured value of the mast tilt angle to be temporarily lower than the actual deflection, preventing the monitoring system from timely identifying the risk of exceeding limits in the early stages of a dangerous situation. At the same time, the connecting bolts and contact surfaces in the prefabricated foundation will experience recoverable micro-displacements after a short-term impact, causing the bending stiffness of the slewing bearing to decrease instantaneously, further amplifying the uncertainty of the structural response. Existing monitoring systems often experience alarm lag or misjudgment due to the lack of a mechanism to identify this short-term reverse oscillation phenomenon, especially when the frequency of the main wind speed energy zone is close to the inherent response frequency of the slewing system.

[0005] Specifically, the dynamic behavior of the slewing mast mechanism under low-speed, heavy-load conditions is not a linear response. External disturbances undergo multiple dynamic processes before reaching the mast angle sensor, including gear backlash, mechanical friction, and micro-displacement of the foundation. This process includes a brief reversal of the mast tilt signal when the external load increases sharply. During this phase, the monitoring system receives a smaller angle change, thus underestimating the instantaneous danger. Because this short-term reversal only occurs under rapid load increases and lasts for an extremely short time, traditional smoothing filters or fixed-time-window monitoring algorithms struggle to capture it. Consequently, the system fails to trigger an alarm in time at the crucial moment when a response is most needed, creating a blind spot in anti-tipping safety monitoring. Summary of the Invention

[0006] This invention provides an anti-tipping safety monitoring system for a pole slewing support mechanism, which solves the technical problems mentioned in the background art.

[0007] This invention provides an anti-tipping safety monitoring system for a pole slewing support mechanism, comprising:

[0008] The working condition and environment acquisition module collects the working condition parameters of the pole and the environmental wind parameters of the working environment, and inputs the structural parameters of the pole. The working condition parameters include attitude parameters, load parameters and motion parameters, and the structural parameters include nominal overturning stiffness and overturning moment limit.

[0009] The external overturning moment module calculates the external overturning moment, its peak value, and its rate of change over time based on load parameters, motion parameters, and environmental wind parameters.

[0010] The dynamic frequency domain identification module obtains the equivalent time delay and the corresponding angular frequency of the zero point in the right half-plane through frequency domain identification. It calculates the beat frequency by combining the operating parameters and performs spectrum analysis on the environmental wind parameters to determine the representative frequency of the main energy zone of the gust. The frequency band overlap index is obtained by comparison.

[0011] The equivalent moment gap module determines the equivalent moment gap based on the equivalent time delay, structural parameters and the time change rate of the external overturning moment. It then obtains the corrected peak value by combining the peak value of the external overturning moment. Finally, it constructs a safety judgment value based on the corrected peak value, the overturning moment limit in the structural parameters and the frequency band overlap index.

[0012] The safety assessment module outputs the anti-overturning safety assessment result of the pole based on the safety assessment value.

[0013] The beneficial effects of this invention include: by introducing a joint judgment mechanism based on equivalent time delay, the corresponding angular frequency of the right half-plane zero point, and the frequency band coincidence index, it improves upon the problem of missed detection of short-term overturning risks in traditional monitoring. Thus, under sudden changes in external overturning moment or gust impacts, it can identify the early reverse response of the mast angle in real time and automatically correct the peak overturning moment, ensuring that the monitoring results are consistent with the actual stress state. This invention can output early warnings of abnormalities in the early stages of dangerous conditions, effectively improving the anti-overturning response speed and judgment accuracy of the slewing support mechanism, thereby significantly improving the overall safety level of high-altitude hoisting operations. Attached Figure Description

[0014] Figure 1 This is a block diagram of an anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to the present invention;

[0015] Figure 2 This is a bottom view of the pole-mounted rotary support mechanism of the present invention. Detailed Implementation

[0016] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0017] like Figure 1 As shown, an anti-tipping safety monitoring system for a slewing support mechanism includes:

[0018] The working condition and environment acquisition module collects the working condition parameters of the pole and the environmental wind parameters of the working environment, and inputs the structural parameters of the pole. The working condition parameters include attitude parameters, load parameters and motion parameters, and the structural parameters include nominal overturning stiffness and overturning moment limit.

[0019] The external overturning moment module calculates the external overturning moment, its peak value, and its rate of change over time based on load parameters, motion parameters, and environmental wind parameters.

[0020] The dynamic frequency domain identification module obtains the equivalent time delay and the corresponding angular frequency of the zero point in the right half-plane through frequency domain identification. It calculates the beat frequency by combining the operating parameters and performs spectrum analysis on the environmental wind parameters to determine the representative frequency of the main energy zone of the gust. The frequency band overlap index is obtained by comparison.

[0021] The equivalent moment gap module determines the equivalent moment gap based on the equivalent time delay, structural parameters and the time change rate of the external overturning moment. It then obtains the corrected peak value by combining the peak value of the external overturning moment. Finally, it constructs a safety judgment value based on the corrected peak value, the overturning moment limit in the structural parameters and the frequency band overlap index.

[0022] The safety assessment module outputs the anti-overturning safety assessment result of the pole based on the safety assessment value.

[0023] In one embodiment of the present invention, the calculation of the external overturning moment, its peak value, and its rate of change over time is performed based on load parameters, motion parameters, and environmental wind parameters, including:

[0024] Calculate the overturning moment under load ;in, For the real-time tension at the first lifting point, For the real-time tension of the second lifting point, This is the real-time horizontal distance from the first lifting point to the center of rotation of the boom. This is the real-time horizontal distance from the second lifting point to the center of rotation of the boom;

[0025] Calculate wind-induced overturning moment ;in, For ambient air density, This refers to the wind load factor corresponding to the combination of pole erection and hoisting. This is the reference windward area for the pole and lifting assembly. For real-time ambient wind speed, The real-time horizontal lever arm from the point of application of the wind load to the center of rotation of the pole;

[0026] Calculate the external overturning moment ;

[0027] Determine the peak value of the external overturning moment ;in, The length of the sliding time window;

[0028] Calculate the rate of change of external overturning moment over time ;in, This represents the sampling time interval.

[0029] The overturning moment is the moment generated by the double-point lifting, which causes the boom to overturn around the center of rotation. The unit is Newton-meter. The overturning moment is obtained by superimposing the overturning moments generated by each of the two lifting points. Since the two lifting points operate independently, the moment of each lifting point needs to be calculated separately and then summed.

[0030] The real-time tension at the first lifting point is the tension generated by the load on the boom, which is collected in real time by the sensor at the first hook. The unit is Newtons. The data collection must be done through a tension sensor with an accuracy of 0.5 or higher. The sensor is installed at the connection between the pulley block and the hook at the first lifting point to ensure direct collection of the load force.

[0031] Similarly, obtain the real-time tension at the second suspension point.

[0032] The real-time horizontal distance from the first lifting point to the slewing center of the pole is the straight-line distance from the projection point of the first lifting point on the horizontal plane to the slewing center of the pole (i.e., the geometric center of the pole base), in meters. The data must be collected using a laser rangefinder with an accuracy of ±1 mm. The laser rangefinder is installed on the luffing trolley corresponding to the first lifting point, and the measurement direction must be parallel to the horizontal plane to avoid the influence of vertical displacement.

[0033] Similarly, obtain the real-time horizontal distance from the second lifting point to the center of the boom's rotation.

[0034] The wind-induced overturning moment is the moment generated by the ambient wind on the boom and the load combination, causing the boom to overturn around the center of rotation. The unit is Newton-meter. It needs to be calculated in combination with real-time wind parameters and structural shape. The calculation formula is based on the standard form of the wind load calculation formula.

[0035] Ambient air density is the mass of air per unit volume at the work site, measured in kilograms per cubic meter. Its value varies with temperature and air pressure and needs to be calculated by collecting parameters in real time through temperature and pressure sensors. The calculation range is limited to an ambient temperature of -10 degrees Celsius to 35 degrees Celsius and an air pressure of 95 kPa to 105 kPa (covering most pole-lifting work environments). In the formula, 287 is the dry air gas constant (unit: joules per (kilogram-Kelvin)), which is a standard constant in the field of fluid mechanics.

[0036] The wind load factor corresponding to the combination of scaffolding and suspended loads is a dimensionless coefficient characterizing the amplification of the force exerted by the wind on the scaffolding and suspended load combination, and is related to the structural shape and airflow direction. Specifically, the wind load factor for cylindrical scaffolding is 0.8-1.2 (smaller values ​​for smooth surfaces, larger values ​​for rusted surfaces or attached parts), and the wind load factor for suspended loads of tower components is 1.3-1.8 (larger values ​​for more irregular component cross-sections and more connecting parts). The combined wind load factor is equal to (scaffolding windward area multiplied by scaffolding wind load factor plus suspended load wind load factor multiplied by suspended load wind load factor) divided by (scaffolding windward area plus suspended load windward area).

[0037] The reference windward area of ​​the gantry and sling combination is the vertical projected area of ​​the gantry and sling combination in the direction of wind load, in square meters. The projected areas of the gantry and sling need to be calculated separately and then summed. Since the gantry is cylindrical and the sling is mostly an irregular component, it needs to be calculated according to their respective shape characteristics (the gantry is calculated by multiplying the outer diameter and the effective height, and the sling is calculated by the maximum projected area).

[0038] Real-time ambient wind speed is the real-time horizontal speed of the wind at the work site, measured in meters per second. It needs to be collected in real time by a wind speed sensor. The wind speed sensor is installed at the top of the pole (at the same height as the suspension point to ensure that the collected wind speed is consistent with the wind field calculated by the wind-induced overturning moment). The sensor accuracy needs to reach ±0.3 meters per second to meet the requirements for measuring gusts near the ground.

[0039] The real-time horizontal lever arm from the point of application of the wind load to the center of rotation of the gantry is the straight-line distance from the projection point of the resultant force of the wind load on the horizontal plane to the center of rotation of the gantry, in meters. Since the wind load acts on the gantry and the load at different locations, it is necessary to first determine the height of the point of application of the resultant force, and then obtain the horizontal offset (i.e., the horizontal lever arm) through the attitude sensor. By integrating the structural attitude and the wind load distribution, the lever arm calculation can be made accurate.

[0040] The external overturning moment is the total overturning moment caused by the combined effect of the overturning moment generated by the load and the overturning moment generated by the wind. The unit is Newton-meter. It directly reflects the overturning risk of the pole. Since the load and the wind are the two core external loads for the pole to overturn, the total effect needs to be calculated by directly superimposing them.

[0041] The peak external overturning moment is the maximum value of the external overturning moment within a set sliding time window, measured in Newton-meters. It is used to capture sudden increases in moment caused by short-term gusts or asynchronous amplitude changes of the two arms. The length of the sliding time window must match the duration of the near-surface gust to ensure that the peak value can cover the entire gust cycle and avoid missing dangerous peak values.

[0042] The sliding time window length is the length of the time interval used to calculate the peak external overturning moment, in seconds. It needs to match the typical duration of gusts, and the value is based on historical wind speed data (or industry experience if no historical data is available) to ensure that the time window can completely cover the moment fluctuation caused by a gust. Specifically, the sliding time window length is equal to 1.5 times the average duration of gusts at the work site (the average duration of gusts is calculated by averaging the duration of gusts during the same period over the past 3 months (e.g., 9-17:00 daily, the common working time for pole lifting)). If no historical data is available, 20 seconds is used (covering the range of gust durations in most areas).

[0043] The rate of change of external overturning moment over time is the ratio of the difference between the external overturning moments at two adjacent sampling times to the sampling time interval, measured in Newton-meters per second. It is used to reflect how fast the moment changes (the greater the rate of change, the faster the risk of overturning increases). The calculation must be based on continuous sampling data to ensure that the difference reflects the real-time trend of change.

[0044] The sampling time interval is the time interval for collecting external overturning moment data, in seconds. It must match the sensor sampling frequency and satisfy Nyquist's theorem (the sampling frequency must be more than twice the highest frequency of the signal). Since the highest frequency of gusts usually does not exceed 5 Hz, the sampling frequency is set to 10 Hz, corresponding to a sampling time interval of 0.1 seconds, to ensure that rapid changes in torque can be captured.

[0045] In one embodiment of the present invention, the equivalent time delay and the corresponding angular frequency of the right half-plane zero point are obtained through frequency domain identification, and the beat frequency is calculated in combination with operating parameters. Spectral analysis of environmental wind parameters is performed to determine the representative frequency of the gust's main energy zone, including:

[0046] Calculate the frequency response function of external overturning moment and mast tilt angle. ;in, The imaginary unit, Angular frequency, The cross-power spectral density is the sum of the external overturning moment and the real-time tilt angle of the mast. The power spectral density of the external overturning moment;

[0047] Determine the equivalent delay :

[0048] ;in, The parameter to be estimated is the equivalent time delay. It is the frequency response function. The equivalent inertia of the pole rotation, The fractional damping coefficient, It is a fractional exponent. The nominal overturning stiffness of the pole;

[0049] Determine the angular frequency corresponding to the zero point in the right half-plane. ;in, The angular frequency corresponding to the zero point in the right half-plane;

[0050] Calculate beat frequency ;in, The real-time angular velocity of the first trolley. This refers to the real-time angular velocity of the second trolley.

[0051] Obtain the representative frequency of the gust's main energy region ;in, This represents the frequency of the main energy region of gusts. For frequency variables, To analyze the lower limit of the frequency band, To analyze the upper limit of the frequency band, This represents the power spectral density of the real-time ambient wind speed.

[0052] The frequency response function of external overturning moment and mast tilt angle describes the transfer characteristics of the system at different angular frequencies when the external overturning moment is the input and the mast tilt angle is the output. It needs to be calculated by power spectral density. Before the calculation, the data needs to be preprocessed using the Welch method (segmented windowing to reduce spectral leakage).

[0053] Angular frequency is a physical quantity that describes the rate of periodic change of a signal. Its unit is radians per second. It has a fixed conversion relationship with the frequency commonly used in engineering and is used to define the frequency axis of the frequency response function.

[0054] The cross-power spectral density of the external overturning moment and the real-time mast tilt angle is a physical quantity that describes the correlation and phase relationship between the two time series at different angular frequencies. The unit is (N·m·radian) squared per radian. It needs to be calculated by the Welch method to ensure the accuracy of the spectral estimation. The data segment length is 2048 points, the Hanning window is a windowed type, and the overlap rate is 50%.

[0055] The power spectral density of the external overturning moment is a physical quantity that describes the power distribution of the external overturning moment time series at different angular frequencies. Its unit is (N·m) squared per radian. It is the basis for calculating the frequency response function and also needs to be calculated using the Welch method.

[0056] Equivalent time delay is a physical quantity characterizing the contact establishment lag caused by both backlash and friction in a rotary transmission system. It is measured in seconds and is obtained by fitting the frequency response function to a pre-defined model. The fitting method uses the least squares approach (minimizing the error between the measured frequency response and the model frequency response). Specifically, it includes:

[0057] The first step is to set the initial value range of the equivalent time delay parameter to be estimated to be 0.01-0.5 seconds (the time delay corresponding to the backlash in a low-speed heavy-load transmission system is usually in this range).

[0058] The second step is to substitute the initial values ​​into the model frequency response function. This model frequency response function is obtained by multiplying the delay correction fraction and the structural response fraction:

[0059] The delay correction fraction (Padé approximation) is: its numerator is (1 minus (half of the product of the imaginary unit, angular frequency, and the equivalent delay parameter to be estimated)), and its denominator is (1 plus (half of the product of the imaginary unit, angular frequency, and the equivalent delay parameter to be estimated)).

[0060] Structural response fraction: Its numerator is 1, and its denominator is the algebraic sum of the following three terms:

[0061] The first term is (the negative equivalent moment of inertia of the pole rotation multiplied by the square of the angular frequency), the second term is (the fractional damping coefficient multiplied by the fractional power of the product of the imaginary unit and the angular frequency), and the third term is (the nominal overturning stiffness of the pole).

[0062] The third step is to calculate the sum of squared errors between the measured frequency response function and the model frequency response function, and adjust the estimated parameter of the equivalent time delay to minimize the sum of squared errors. The estimated parameter at this time is the equivalent time delay.

[0063] The equivalent time delay parameter to be estimated is an initial variable set when fitting the equivalent time delay. The unit is seconds, and its value range needs to be set in conjunction with the backlash size of the rotary transmission system (the larger the backlash, the larger the initial value). It is used to obtain the final equivalent time delay through least squares iteration.

[0064] The equivalent moment of inertia of the boom slewing is the equivalent inertial parameter that converts the mass of the boom head slewing components (including the slewing bearing, luffing trolley, and part of the boom) to the center of rotation. The unit is kilogram-square meter, and it needs to be calculated from the component mass and the rotation radius. Specifically, the equivalent moment of inertia of the boom slewing is equal to (the mass of the slewing bearing multiplied by the square of its rotation radius) plus (the mass of each luffing trolley multiplied by the square of its maximum distance from the center of rotation) plus (1 / 3 multiplied by the boom mass multiplied by the square of the boom length). The mass of each component is obtained from the equipment manual, and the rotation radius and boom length are the boom design parameters.

[0065] The fractional-order damping coefficient is a parameter describing the magnitude of hysteretic damping caused by slight slippage at the bolt interface of a prefabricated foundation. It is expressed as a fractional power of N·m·s and needs to be set based on the preload of the foundation bolts and the material of the contact surface. Specifically, the fractional-order damping coefficient equals 0.05 multiplied by (0.8 power of the total preload of the foundation bolts). The total preload of the foundation bolts is calculated based on the bolt specifications and preload torque (e.g., an M30 bolt with a preload torque of 300 N·m corresponds to a preload of 200 kN). The coefficient 0.05 is determined based on the material properties of the steel-to-steel contact surface. The fractional-order exponent describes the fractional-order damping characteristics, reflecting the strength of the hysteretic memory effect at the foundation interface.

[0066] The angular frequency corresponding to the zero point in the right half-plane is an angular frequency parameter that describes the reverse response characteristics of the system. The unit is radians per second, and its value is directly determined by the equivalent time delay (derived from the mathematical properties of the Padé[1 / 1] approximation). Specifically, the angular frequency corresponding to the zero point in the right half-plane is equal to 2 divided by the equivalent time delay.

[0067] Beat frequency describes the frequency of periodic fluctuations in torque difference caused by the difference in angular velocity between the two trolleys during asynchronous luffing. It is measured in Hertz and needs to be calculated using the real-time angular velocities of the two trolleys, which are acquired by the encoders of the luffing trolleys. Specifically, beat frequency is equal to the absolute value of the difference between the real-time angular velocities of the first and second trolleys divided by 2 and multiplied by pi. The real-time angular velocities of the first and second trolleys are acquired by incremental encoders mounted on the shaft of the luffing motor (resolution 1000 lines / revolution, sampling frequency 10 Hertz).

[0068] The real-time angular velocity of the first trolley is the angular velocity of the first luffing trolley moving along the boom, and the real-time angular velocity of the second trolley is the angular velocity of the second luffing trolley moving along the boom. The unit is radians per second, which is used to calculate the beat frequency. The acquisition device is an incremental encoder.

[0069] The representative frequency of the gust's main energy zone is a characteristic frequency describing the concentrated energy band of near-surface gusts, measured in Hertz. It needs to be determined by the peak position of the wind speed power spectral density, and the analysis frequency band needs to cover the main energy distribution of gusts. Specifically, the first step is to set the lower limit of the analysis frequency band to 0.01 Hertz and the upper limit to 0.5 Hertz (more than 90% of near-surface gust energy is concentrated in this frequency band); the second step is to use the Welch method to calculate the power spectral density of real-time ambient wind speed (segment length 2048 points, Hanning window, overlap rate 50%); the third step is to find the frequency corresponding to the maximum value of the real-time ambient wind speed power spectral density within the analysis frequency band, which is the representative frequency of the gust's main energy zone.

[0070] The frequency variable is used to describe the frequency axis of the power spectral density. The unit is Hertz, and the value range is consistent with the analysis frequency band (0.01-0.5 Hertz). It is a mathematical variable used to calculate the representative frequency of the main energy region of gusts.

[0071] The lower limit of the analysis band is the lowest frequency set when determining the representative frequency of the main energy zone of gusts. The unit is Hertz, and the value is based on the energy distribution characteristics of near-surface gusts (long-period winds below 0.01 Hertz have minimal impact on overturning moment).

[0072] The upper limit of the analysis band is the highest frequency set when determining the representative frequency of the main energy zone of gusts. The unit is Hertz, and the value is based on the fact that the energy of gusts above 0.5 Hertz accounts for less than 10%.

[0073] The power spectral density of real-time environmental wind speed is a physical quantity describing the power distribution of a real-time environmental wind speed time series at different frequencies. Its unit is squared per hertz (m / s), and it forms the basis for determining the representative frequency of the main energy region of gusts. Specifically, the power spectral density of real-time environmental wind speed is calculated using the Welch method. The steps are as follows: First, the wind speed time series is segmented into 2048 data points with a 50% overlap. Second, a Hanning window is applied to each segment. Third, a Fourier transform is performed on each segment, and the average value (each segment's Fourier transform multiplied by its conjugate) is calculated, which is the power spectral density of the real-time environmental wind speed.

[0074] In one embodiment of the present invention, the frequency band overlap index includes:

[0075] Calculate the similarity of beat frequency overlap ;in, The angular frequency smoothing coefficient, It is a natural exponential function;

[0076] Calculate the overlap similarity of the main energy regions of gusts ;

[0077] The larger value between the frequency overlap similarity and the gust main energy region overlap similarity is taken as the frequency band overlap index.

[0078] Beat frequency overlap similarity is a dimensionless parameter that characterizes the degree of closeness between the angular frequency corresponding to the zero point in the right half-plane and the angular frequency corresponding to the beat frequency (2 times pi multiplied by the beat frequency). The value ranges from 0 to 1. The closer the value is to 1, the more serious the overlap of the two frequency bands, and the higher the risk of the system's reverse response being amplified.

[0079] The angular frequency smoothing coefficient is a dimensionless parameter used to reduce the impact of measurement errors on the angular frequency corresponding to the zero point in the right half-plane and the representative frequency of the beat frequency / gust main energy region on the similarity calculation results. Its value must match the accuracy of the angular frequency measurement. Specifically, the angular frequency smoothing coefficient is determined based on the angular frequency measurement error: 0.1 when the measurement error is ≤0.05 radians per second, 0.15 when the measurement error is >0.05 and ≤0.1 radians per second, 0.2 when the measurement error is >0.1 radians per second, and 0.15 by default when there is no measurement error data.

[0080] The natural exponential function is a mathematical tool used to convert the difference between the angular frequency corresponding to the zero point of the right half-plane and the target angular frequency (the angular frequency corresponding to the frequency represented by the beat frequency / gust main energy region) into a similarity between 0 and 1. Its base is the natural constant (approximately 2.718), which is used to ensure that the similarity decreases monotonically as the difference in angular frequency increases.

[0081] The similarity of the gust main energy region is a dimensionless parameter that characterizes the degree of closeness between the angular frequency corresponding to the zero point of the right half plane and the angular frequency corresponding to the representative frequency of the gust main energy region (2 times pi multiplied by the representative frequency of the gust main energy region). The value ranges from 0 to 1. The closer the value is to 1, the more serious the overlap of the two frequency bands, and the stronger the amplification effect of the gust on the reverse response.

[0082] The frequency band overlap index is a dimensionless parameter that comprehensively reflects the severity of frequency band overlap between two types of scenarios: the angular frequency corresponding to the zero point in the right half-plane and the beat frequency and the representative frequency of the main energy zone of the gust. The value ranges from 0 to 1. The larger the value, the higher the risk of reverse response caused by frequency band overlap in the system, and it should be given priority in the safety assessment.

[0083] In one embodiment of the present invention, determining the equivalent moment gap based on the equivalent time delay, structural parameters, and the time rate of change of the external overturning moment includes:

[0084] Calculate early angle underestimation ;

[0085] Calculate the equivalent moment gap .

[0086] Early angle underestimation is caused by the equivalent time delay of the slewing drive system. It is an underestimation of the mast tilt angle measurement relative to the actual tilt angle value in the early stage of a sudden increase in external overturning moment. The unit is radians. It is used to quantitatively reflect the angle measurement deviation caused by the mast swinging backward first in the reverse response.

[0087] The equivalent moment gap is a physical quantity that converts the early angle underestimation into a moment unit, with the unit being Newton-meter. It is used to quantitatively characterize the degree of underestimation of the overturning moment risk caused by the angle underestimation. The relationship between angle and moment needs to be established through the nominal overturning stiffness of the mast.

[0088] In one embodiment of the present invention, the corrected peak value is obtained by combining the peak value of the external overturning moment, including:

[0089] The sum of the peak external overturning moment and the equivalent moment gap is used as the corrected peak value.

[0090] The corrected peak value is the actual overturning moment peak value of the pole after considering the underestimation of torque risk caused by early angle underestimation. The unit is Newton-meter. This peak value can more realistically reflect the actual overturning risk of the pole and avoid the risk omission caused by reverse response.

[0091] In one embodiment of the present invention, a safety judgment value is constructed based on the corrected peak value, the overturning moment limit in the structural parameters, and the frequency band overlap index, including:

[0092] The ratio of the corrected peak value to the preset overturning moment limit of the pole is used as the reference ratio.

[0093] The safety judgment value is obtained by multiplying the frequency band overlap index by the benchmark ratio.

[0094] The reference ratio is a dimensionless parameter that characterizes how close the corrected peak value is to the overturning moment limit of the pole. The value ranges from 0 to ∞. The closer the value is to 1, the closer the actual load is to the safety limit. A value greater than 1 indicates that the actual load has exceeded the limit.

[0095] The safety judgment value is a dimensionless risk quantification index that combines the degree to which the actual load approaches the limit (baseline ratio) with the risk amplification caused by frequency band overlap (frequency band overlap index). The value ranges from 0 to ∞, and the larger the value, the higher the risk of the pole overturning.

[0096] In one embodiment of the present invention, the output of the anti-overturning safety judgment result of the pole based on the safety judgment value includes:

[0097] Calculate the difference between 1 and the safety judgment value. If the difference is greater than or equal to 0, it is judged as safe; otherwise, it is judged as abnormal.

[0098] The difference between 1 and the safety judgment value is a dimensionless parameter characterizing the safety margin of the pole anti-overturning. The value range is -∞-1. The larger the difference, the higher the safety margin. A difference less than 0 indicates that the safety margin is negative (exceeding the limit). 1 is the critical judgment benchmark (because when the safety judgment value = 1, it means that the actual load after the risk is amplified just reaches the overturning moment limit).

[0099] The safety in the anti-overturning safety assessment result of the pole means that the actual overturning risk that the pole currently bears, after risk amplification, does not exceed the structural limit, and there is a sufficient safety margin, so there is no need to trigger an early warning; specifically, when the difference between 1 and the safety assessment value is ≥0, the safety assessment value is ≤1, that is, the corrected peak value after risk amplification is ≤ the overturning moment limit, and the pole is in an acceptable safety state.

[0100] An anomaly in the safety assessment result of the pole anti-overturning mechanism means that the actual overturning risk that the pole is currently bearing, after risk amplification, has exceeded the structural limit, the safety margin is negative, and an early warning needs to be triggered immediately; specifically, when the difference between 1 and the safety assessment value is <0, the safety assessment value is >1, that is, the corrected peak value after risk amplification is > the overturning moment limit, and the pole is in a dangerous state.

[0101] In one embodiment of the present invention, such as Figure 2 The image shown is a bottom view of the slewing support mechanism, including the first lifting point and the second lifting point.

[0102] The embodiments of this example have been described above. However, this example is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this example, and all of them are within the protection scope of this example.

Claims

1. A safety monitoring system for preventing overturning of a slewing support mechanism, characterized in that, include: The working condition and environment acquisition module collects the working condition parameters of the pole and the environmental wind parameters of the working environment, and inputs the structural parameters of the pole. The working condition parameters include attitude parameters, load parameters and motion parameters, and the structural parameters include nominal overturning stiffness and overturning moment limit. The external overturning moment module calculates the external overturning moment, its peak value, and its rate of change over time based on load parameters, motion parameters, and environmental wind parameters. The dynamic frequency domain identification module obtains the equivalent time delay and the corresponding angular frequency of the zero point in the right half-plane through frequency domain identification. It calculates the beat frequency by combining the operating parameters and performs spectrum analysis on the environmental wind parameters to determine the representative frequency of the main energy zone of the gust. The frequency band overlap index is obtained by comparison. The equivalent moment gap module determines the equivalent moment gap based on the equivalent time delay, structural parameters and the time change rate of the external overturning moment. It then obtains the corrected peak value by combining the peak value of the external overturning moment. Finally, it constructs a safety judgment value based on the corrected peak value, the overturning moment limit in the structural parameters and the frequency band overlap index. The safety assessment module outputs the anti-overturning safety assessment result of the pole based on the safety assessment value.

2. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 1, characterized in that, Based on load parameters, motion parameters, and environmental wind parameters, calculate the external overturning moment, its peak value, and its rate of change over time, including: Calculate the overturning moment under load ;in, For the real-time tension at the first lifting point, For the real-time tension of the second lifting point, This is the real-time horizontal distance from the first lifting point to the center of rotation of the boom. This is the real-time horizontal distance from the second lifting point to the center of rotation of the boom; Calculate wind-induced overturning moment ;in, For ambient air density, This refers to the wind load factor corresponding to the combination of pole erection and hoisting. This is the reference windward area for the pole and lifting assembly. For real-time ambient wind speed, The real-time horizontal lever arm from the point of application of the wind load to the center of rotation of the pole; Calculate the external overturning moment ; Determine the peak value of the external overturning moment ;in, The length of the sliding time window; Calculate the rate of change of external overturning moment over time ;in, This represents the sampling time interval.

3. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 2, characterized in that, The equivalent time delay and the corresponding angular frequency of the right half-plane zero point are obtained through frequency domain identification. The beat frequency is calculated in conjunction with operating parameters, and spectral analysis of environmental wind parameters is performed to determine the representative frequency of the gust's main energy region, including: Calculate the frequency response function of external overturning moment and mast tilt angle. ;in, The imaginary unit, Angular frequency, The cross-power spectral density is the sum of the external overturning moment and the real-time tilt angle of the mast. The power spectral density of the external overturning moment; Determine the equivalent delay : ;in, The parameter to be estimated is the equivalent time delay. It is the frequency response function. The equivalent inertia of the pole rotation, The fractional damping coefficient, It is a fractional exponent. The nominal overturning stiffness of the pole; Determine the angular frequency corresponding to the zero point in the right half-plane. ;in, The angular frequency corresponding to the zero point in the right half-plane; Calculate beat frequency ;in, The real-time angular velocity of the first trolley. This refers to the real-time angular velocity of the second trolley. Obtain the representative frequency of the gust's main energy region ;in, This represents the frequency of the main energy region of gusts. For frequency variables, To analyze the lower limit of the frequency band, To analyze the upper limit of the frequency band, This represents the power spectral density of the real-time ambient wind speed.

4. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 3, characterized in that, Frequency band overlap index, including: Calculate the similarity of beat frequency overlap ;in, The angular frequency smoothing coefficient, It is a natural exponential function; Calculate the overlap similarity of the main energy regions of gusts ; The larger value between the frequency overlap similarity and the gust main energy region overlap similarity is taken as the frequency band overlap index.

5. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 4, characterized in that, Based on the equivalent time delay, structural parameters, and the time rate of change of the external overturning moment, the equivalent moment gap is determined, including: Calculate early angle underestimation ; Calculate the equivalent moment gap .

6. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 5, characterized in that, The corrected peak value is obtained by combining the peak value of the external overturning moment, including: The sum of the peak external overturning moment and the equivalent moment gap is used as the corrected peak value.

7. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 6, characterized in that, Safety judgment values ​​are constructed based on the corrected peak value, the overturning moment limit in the structural parameters, and the frequency band coincidence index, including: The ratio of the corrected peak value to the preset overturning moment limit of the pole is used as the reference ratio. The safety judgment value is obtained by multiplying the frequency band overlap index by the benchmark ratio.

8. The anti-tipping safety monitoring system for a pole-mounted slewing support mechanism according to claim 7, characterized in that, The safety assessment results for the pole anti-overturning system are output based on the safety assessment values, including: Calculate the difference between 1 and the safety judgment value. If the difference is greater than or equal to 0, it is judged as safe; otherwise, it is judged as abnormal.

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