Crane load monitoring system and method for inhibiting swing

Abstract

The invention relates to the technical field of automatic control, in particular to a crane load monitoring system and method for restraining swing, and aims to overcome the technical defects that according to an existing swing restraining scheme, control lag, effect attenuation and oscillation aggravation exist, and swing cannot be actively restrained from the root of movement of a crane. The system comprises a sensing module, a coupling model calculation module, a feedforward control module, a feedback correction module and an execution adaptation module. Wherein the coupling model calculation module is used for prospectively calculating a load swing trend based on crane motion parameters, and the feedforward control module is used for generating a compensation instruction in advance according to a predicted swing angle; and the feedback correction module performs closed-loop correction by using the actual swing angle. By the adoption of the technical scheme, efficient, active and whole-process suppression of crane load swing can be achieved, swing generation is weakened from the source, the operation efficiency is improved, and the operation threshold is lowered.

Description

Technical Field

[0001] The present invention relates to the technical field of crane control, and in particular to a crane load monitoring system and method for suppressing sway. Background Art

[0002] Cranes, as essential lifting equipment, are widely used in industrial production, construction, logistics, and transportation. Load sway is a common and unavoidable phenomenon during crane operations, especially during lifting, moving, or stopping operations, when loads swing due to inertia. This sway not only increases operating time but can also pose a threat to the surrounding environment and personnel safety. This sway is particularly problematic in confined spaces or complex working conditions.

[0003] During the lifting process of a large crane, load sway caused by the crane's movement and operation accounts for more than 70%. This mainly includes the centrifugal force coupling of the crane's slewing mechanism starting and stopping (when the crane rotates, the centrifugal force and the Coriolis force are superimposed, causing the load to sway in a spiral shape) and the load sway caused by the inertia force of the crane's acceleration and deceleration (typically, the greater the acceleration change, the more obvious the swing amplitude. For example, an emergency stop operation can instantly expand the swing angle to a safety threshold of >5°). This type of sway will cause the unloading operation to be suspended, and the operator must manually eliminate the sway, which takes more than 30% or even more time of the entire handling process.

[0004] Current crane load sway suppression technologies to address the aforementioned issues suffer from high costs, complex modifications, long installation cycles, poor adaptability, delayed response, and low efficiency, hindering widespread practical application. The present invention relates to a crane load monitoring method and system for sway suppression, aiming to address the safety hazards and efficiency issues associated with load sway during crane hoisting operations. Summary of the Invention

[0005] The purpose of the present invention is to provide a crane load monitoring method and system for suppressing sway, so as to solve the technical problems described in the background art of the existing sway suppression scheme based on pure a posteriori feedback control, such as control lag, effect attenuation and even oscillation aggravation caused by system delay, and to overcome the fundamental defect of the scheme that fails to actively suppress the source of sway, which is the crane's own movement.

[0006] To achieve the aforementioned objectives, the present invention provides a crane load monitoring system for suppressing sway. The system comprises a perception module, a coupling model calculation module, a feedforward control module, a feedback correction module, and an execution adaptation module. Definite data communication and control logic connections are established between the perception module, coupling model calculation module, feedforward control module, feedback correction module, and execution adaptation module.

[0007] Specifically, the sensing module is used to perform real-time, high-frequency measurement and acquisition of key kinematic and dynamic parameters during crane operation, as well as the load's posture parameters. The sensing module physically comprises a dual-axis inclination sensor, a rotary encoder, a variable-length encoder, a lifting-length encoder, and a current sensor. The dual-axis inclination sensor is mounted on the load's sling or hook assembly and secured to a magnetic base, ensuring its measurement reference plane is closely aligned with the load's vertical orientation. The dual-axis inclination sensor is a capacitive accelerometer based on microelectromechanical systems (MEMS) technology. Its measurement range is set to ±15 degrees and its static measurement accuracy is better than ±0.1 degrees. It integrates temperature compensation and signal conditioning circuitry, outputting filtered and calibrated angle signals. The rotary encoder is an incremental photoelectric rotary encoder, physically mounted on the transmission output shaft of the crane's slewing mechanism, to accurately measure the angular displacement of the crane's superstructure relative to the underlying chassis. The resolution of the rotary encoder is set to 1024 lines per revolution, and its output signal is a two-phase orthogonal pulse signal A and B. By counting and detecting the frequency of the pulse signal, the rotational angular position, rotational angular velocity ω, and rotational angular acceleration α can be analyzed. The variable amplitude stroke encoder and the lifting stroke encoder are both cable-type linear displacement sensors, which are installed on the side of the crane's variable amplitude mechanism drum and the lifting mechanism drum respectively. The ends of the cable ropes rotate synchronously with the drums. The variable amplitude stroke encoder is used to measure the radial displacement of the trolley or boom, thereby determining the current variable amplitude r, and calculating the radial velocity v of the variable amplitude mechanism based on its displacement change rate. r . The lifting stroke encoder is used to measure the pay-out length of the wire rope, so as to determine the current height of the load suspension point and the effective length L of the wire rope. The measuring range of these two stroke encoders is set to 0 to 50 meters, and the measurement accuracy is better than ±0.5 mm. The current sensor is a closed-loop current sensor based on the Hall effect, and its physical installation method is to be connected in series on one phase of the three-phase power supply circuit of the AC asynchronous motor that drives the lifting mechanism or the amplitude variation mechanism. The rated measurement range of the current sensor is set to 0 to 500 amperes, and the measurement accuracy is ±1% of the full scale. Its function is to monitor the working current of the drive motor in real time. The current signal has a definite functional relationship with the output torque of the motor and the acceleration of the load, thereby indirectly measuring the acceleration a(t) of the load in the lifting or amplitude variation direction.

[0008] Furthermore, the coupling model calculation module, feedforward control module, and feedback correction module are hardware-integrated within an embedded controller. This embedded controller (with a high-performance microcontroller unit (MCU) at its core) is installed in an electrical control cabinet in the crane's central operating room and secured via a DIN rail. The sensors in the perception module are connected to corresponding interfaces on the embedded controller via shielded cables.

[0009] Furthermore, the coupled model calculation module, a set of fixed algorithm programs running on the embedded controller, has the core function of receiving real-time multi-source data from the perception module and, based on a preset rigid-body dynamics model, quantitatively calculating the load sway tendency induced by the crane's active motion. This module is logically divided into two parallel submodules: a centrifugal-Coriolis force coupled swing angle calculation submodule and an inertial force swing angle calculation submodule.

[0010] Furthermore, the centrifugal-Coriolis force coupled swing angle calculation submodule is specifically designed to calculate the predicted swing angle θ1(t) in the tangential plane, resulting from the combined effects of centrifugal force, Coriolis force, and tangential inertial force when the crane performs a combined slewing and luffing motion. The calculation performed by this submodule follows the following integral formula: In this formula, θ1(t) is the swing angle generated by the coupling of rotation and amplitude variation predicted at time t; is the integral time variable The rotational angular velocity measured by the rotary encoder at all times; for The angular acceleration of rotation at the moment is determined by Perform time differentiation operation to obtain; for The amplitude of the variable amplitude is measured by the variable amplitude encoder at any time; for The radial velocity of the luffing mechanism at the moment The time differential operation is performed; k1 and k2 are pre-calibrated dimensionless correction coefficients used to compensate for errors caused by model simplification and unmodeled dynamics. This integral operation is iteratively calculated within the MCU using a discretized numerical integration method (such as the trapezoidal rule or Simpson's rule) with a fixed time step (for example, 10 milliseconds).

[0011] Furthermore, the inertial force swing angle calculation submodule is specifically used to calculate the predicted swing angle θ2(t) in the direction of motion generated by the translational inertial force of the load when the crane is lifting, lowering, or performing horizontal acceleration and deceleration movements. The calculation performed by this submodule follows the following formula: In this formula, θ2(t) is the predicted swing angle caused by the translational inertia force at time t; a(t) is the horizontal or vertical acceleration of the load at time t; g is the acceleration due to gravity, which is set to 9.8 m / s²; L is the current effective length of the wire rope measured by the lifting stroke encoder at time t; L0 is the maximum working length of the wire rope configured for the crane, which is pre-stored in the controller as a fixed parameter; k3 is a pre-calibrated length correction factor related to the wire rope length. Its physical significance is to characterize the influence of the wire rope's own elasticity and mass distribution on the swing period.

[0012] Furthermore, the feedforward control module, another core algorithm running on the embedded controller, receives the predicted swing angles θ1(t) and θ2(t) output by the coupled model calculation module and, based on this prediction, generates proactive, compensatory control instructions in advance. This module is logically divided into two parallel submodules: a submodule for generating swing compensation and a submodule for generating acceleration and deceleration compensation.

[0013] Furthermore, the rotary operation compensation amount generating submodule is used in the rotary feedforward submodule to generate the rotary operation compensation amount based on formula (3): Among them, k p ∈[0.8,1.2] is the proportional coefficient, is t+T predicted based on the centrifugal force-Coriolis force coupling submodule d Time swing angle, T d is the execution delay, T d =100ms; The compensation amount generation submodule is used to generate the acceleration / deceleration operation compensation amount based on formula (4): Among them, k i ∈[0.05,0.1]s -1 is the integration coefficient, Prediction based on the inertial force swing submodule Always swing the corner. Furthermore, the feedback correction module is used to calculate the feedback control amount based on formula (5): Among them, k d ∈[0.1,0.3]s is the differential coefficient, is the error between the measured swing angle and the target swing angle, is the measured swing angle collected by the dual-axis tilt sensor, is the target swing angle, is the error change rate, which is the difference between the two errors divided by the sampling time.

[0014] It should be further explained that in the algorithm of this solution, the proportional coefficient k p , integral coefficient k i , differential coefficient k d It is the core control parameter, and its value directly affects the anti-sway effect (such as the swing angle convergence speed, stability, etc.) and k p 、k i 、k d It is a personalized parameter of the equipment, that is, different cranes (tonnage, type) and different scenarios (load, environment) require different values. Before use, it must be determined through the three steps of "initial setting → on-site debugging → curing and saving". The specific operation method is to first set an initial value according to the range value in this solution, generally the middle value, and adjust one parameter at a time (the change range is ≤10%), and record the swing angle curve until the parameters can stably meet the control objectives of "swing angle suppression rate ≥90% and convergence time ≤12s" after debugging. According to the parameter characteristics, focus on adjusting k in the no-load stage. p At this time, the load inertia is small, and the swing angle change is mainly controlled by the proportional adjustment (k p ) dominates, if only because k p Improper convergence / oscillation results, no need to adjust k i 、k d ; Focus on adjusting k during full load stage i , the residual swing angle is determined by the integral link (k i ) is responsible for compensation. If there is still residual swing angle after stabilization, k is adjusted first. i Rather than k p (Avoid destroying the adjusted dynamic response); focus on adjusting k during the emergency stop phase d : Swing angle mutation is determined by differential link (k d ) suppression, if the emergency stop increase is large, give priority to adjusting k d rather than other parameters.

[0015] The function of the execution adaptation module (14) is to calculate the total control quantity based on formula (6) and output: Among them, sat() is the saturation function, u min 、u max They are the minimum and maximum control quantities allowed by the actuator respectively.

[0016] As another aspect, the present invention provides a crane load monitoring method for sway suppression, implemented on a crane equipped with the aforementioned system. During initial deployment, the method includes a critical system parameter calibration step and a real-time control step that is cyclically executed during daily operations.

[0017] The system parameter calibration step is aimed at determining three key correction coefficients k1, k2, and k3 for the coupling model calculation module. This step specifically includes: S01: Calibration of centrifugal force-Coriolis force coupling coefficient k1. First, control the crane in the state of no lifting and no amplitude change (i.e. v r = 0), it rotates at a known, constant angular velocity ω (e.g., 0.5 rad / s) and maintains a fixed amplitude r (e.g., 15 meters). After the uniform rotation lasts for a set time T (e.g., 10 seconds), the maximum value of the stable tangential swing angle θ1 = 1.2 rad measured by the dual-axis inclination sensor is recorded. Subsequently, the value of the coefficient k1 is calculated using formula (1), which is .

[0018] S02: Calibration of the angular acceleration coupling coefficient k2. First, the crane is controlled to rotate uniformly from rest at a known, constant angular acceleration α (e.g., 0.1 rad / s²) without lifting or amplitude variation, and maintain a fixed amplitude variation r (e.g., 15 meters). After the uniform acceleration rotation lasts for a set time T (e.g., 10 seconds), the maximum value of the stable tangential swing angle θ2 = 0.8 rad measured by the dual-axis inclination sensor is recorded. Subsequently, the value of the coefficient k2 is calculated by formula (2), which is: .

[0019] S03: Calibration of the wire rope length correction coefficient k3. First, control the crane to perform lifting or lowering operations at a known, constant acceleration a (e.g., 0.5 m / s²) without rotation or amplitude change, for a set time T (e.g., 5 seconds). During this process, record the maximum working length L0 (e.g., 30 m) and the current wire rope length L (e.g., 15 m), and measure the maximum value of the stable swing angle θ3 = 0.6 rad using the dual-axis inclination sensor. Calculated using formula (3): .

[0020] After completing the above calibration, the calculated values ​​of k1, k2, and k3 are written into the embedded controller as fixed parameters, and the crane load monitoring system of the present invention can be operated. The specific method is as follows: S1. Real-time collection of multi-source information - collecting the crane's rotation angular velocity ω and angular acceleration through the perception module (10) , amplitude r, radial speed v of the amplitude variation mechanism r , lifting height L, acceleration a in the lifting or luffing direction and load swing angle θ; S2. Based on the parameters collected in step S1, the coupled model calculation module is used to substitute into formula (1) and formula (2) and the pre-stored calibration coefficients k1, k2, and k3 to calculate the predicted swing angles θ1(t) and θ2(t); S3, substitute θ1(t) obtained in step S2 into formula (3) to generate the rotation operation compensation u1, and substitute θ2(t) into formula (4) to generate the acceleration / deceleration operation compensation u2; S4, based on the load swing angle θ collected in step S1 and the target swing angle θ ref = 0, substitute the error e into formula (5) to generate the feedback control quantity u f ; S5, u1, u2 obtained in step S3 and u obtained in step S4 f Substitute into formula (6) to calculate the total control quantity u, and output it to the original control system of the crane through the execution adaptation module to achieve source suppression of sway and process correction.

[0021] By combining the aforementioned system and method, the present invention establishes a dual-closed-loop control architecture that combines forward-looking prediction of crane kinematics with real-time feedback of load posture. Its core lies in establishing and calibrating a dynamic coupling model between the crane's own motion and the load's sway response. This enables the system to predict the amplitude and direction of sway based on upcoming operational instructions before it occurs, and to apply precise counter-compensation forces in advance, significantly reducing sway at its source. This enables efficient and proactive control of crane load sway, improving operational efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 4 is a system block diagram of a crane load monitoring system for suppressing sway according to the present invention.

[0023] Figure 2 This is a schematic diagram of the installation positions of the various measurement sensors of the perception module in the system of the present invention.

[0024] Figure 3 This is a schematic diagram of the electrical signal connection between the sensing module and the embedded controller in the system of the present invention.

[0025] Figure 4 It is a control logic diagram of the system of the present invention that combines feedforward control with feedback correction.

[0026] Figure 5 It is a flow chart of the system parameter calibration step in the method of the present invention.

[0027] Figure 6 It is a schematic diagram of the system operation flow corresponding to the actual operation of the method of the present invention.

[0028] The accompanying drawings are marked as follows: 1. Base; 2. Tower body; 3. Lifting mechanism; 4. Cab; 5. Balance arm; 6. Tower arm; 7. Counterweight; 8. Rotating mechanism; 9. Luffing mechanism; 91. Traveling trolley; 92. Hook assembly; 10. Perception module; 11. Coupling model calculation module; 111. Centrifugal force-Coriolis force coupling swing angle calculation submodule; 112. Inertia force swing angle calculation submodule; 12. Feedforward control module; 121. Rotation operation compensation amount generation submodule; 122. Acceleration and deceleration operation compensation amount generation submodule; 13. Feedback correction module; 14. Execution adaptation module; 21. Dual-axis inclination sensor; 22. Rotary encoder; 23. Luffing stroke encoder; 24. Lifting stroke encoder; 25. Current sensor; 30. Embedded controller. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.

[0030] Reference Figures 1 to 6 The present invention discloses a crane load monitoring system and method for suppressing sway. The system fundamentally overcomes the control lag problem caused by the inherent time delay in signal transmission, computational processing, and mechanical execution in traditional sway suppression technology by mainly constructing a forward-looking prediction model and a real-time feedback correction model.

[0031] Example QTZ80 tower crane transformation: Figure 1 and 2 As shown, the system hardware of the present invention is installed on the above crane (the crane structure includes a base 1, a tower body 2, a hoisting mechanism 3, a cab 4, a balance arm 5, a tower arm 6, a counterweight 7, a slewing mechanism 8 and a luffing mechanism 9). The system architecture and specific installation position diagram are shown in FIG. Figure 1 and 2 As shown, it includes a perception module 10, a coupling model calculation module 11, a feedforward control module 12, a feedback correction module 13, and an execution adaptation module 14. These modules communicate and work together at high speed through a preset, reliable data bus and logic link, forming a whole. Among them, the coupling model calculation module 11, the feedforward control module 12, and the feedback correction module 13 are highly integrated in hardware into a unified embedded controller 30. The perception module 10 is composed of multiple sensor devices distributed at key positions of the crane, such as Figure 3 As shown, they are a dual-axis inclination sensor 21, a rotary encoder 22, an amplitude variable stroke encoder 23, a lifting stroke encoder 24 and a current sensor 25.

[0032] Among them, the dual-axis inclination sensor 21 (model SCA61T, range ±15°, accuracy ±0.1°, power supply DC=5V) is installed on the hook assembly 92 that directly carries the container through a high-strength NdFeB magnetic adsorption base, and is supplemented by a safety cable for secondary fixation to ensure that the sensor can still maintain a rigid connection with the sling during intense movement. The design requirements of this sensor need to adapt to the harsh working environment of high salt fog and high humidity in the port. The sensor integrates a high-precision temperature sensor and a digital temperature compensation algorithm, which can automatically correct the measurement error introduced by temperature drift in a wide temperature range of -40°C to +85°C. At the same time, its built-in Kalman filter algorithm fuses the original acceleration signal, effectively filtering out high-frequency noise caused by motor vibration, structural resonance, etc., and finally outputs the real-time swing angle θ to the embedded controller 30 in the form of a digital signal through the CAN bus interface. meas .

[0033] The rotary encoder 22 (model E6B2-CWZ6C, resolution 1024 lines / turn, output AB phase pulses) is fixed to the output shaft end of the planetary reducer driving the slewing mechanism 8 via a customized coupling and bracket. The luffing stroke encoder 23 (model KTF1-2000, measuring range 0-20m, accuracy ±0.5mm) and the lifting stroke encoder 24, both heavy-duty cable-type linear displacement sensors, are installed on the sides of the crane's luffing mechanism 9 drum and hoisting mechanism 3 drum, respectively. The ends of their cable-type cables rotate synchronously with the drums. The current sensor 25 (model ACS712-50A, measuring range 0-50A, accuracy ±1% FS) is directly connected in series to one phase of the three-phase power supply cable of the AC asynchronous motor driving the hoisting mechanism or luffing mechanism. This current signal indirectly measures the load acceleration a(t) in the lifting or luffing direction.

[0034] The embedded controller 30 (model STM32H743, main frequency 400MHz, with 4 GPIO and 2 UART interfaces) is installed in the electrical control cabinet behind the crane cab 4 and is fixed via a standard DIN rail. The working power supply is taken from the 24V DC power supply in the cabinet.

[0035] The task of the above-mentioned embodiment 1 is to lift a 40-foot standard container from a trailer under the quay crane and perform a compound motion of simultaneous rotation and amplitude adjustment to move the container directly above the target position in the cabin. The specific motion parameters are: lifting height L = 25 meters, the trolley amplitude adjustment from r = 15 meters to r = 35 meters, and the average radial velocity v r=1.0 m / s; simultaneously, the boom slews from 0 degrees to 30 degrees with an average angular velocity of ω = 0.25 rad / s, and a maximum wire rope length of L0 = 30 meters. The moment the operator issues the complex motion command, the crane's load monitoring system, designed to suppress sway, immediately begins operation. The sensing module 10 collects real-time slewing and luffing velocity and acceleration information. Based on this information, the coupled model calculation module 11 predicts within 10 milliseconds the impending complex sway trend caused by the combined effects of centrifugal force, Coriolis force, and tangential and radial inertial forces. Based on this advance prediction, the feedforward control module 12 immediately generates compensatory control commands u1 and u2, and fine-tunes the slewing and luffing motor speeds through the execution adaptation module 14. Throughout the entire motion, the actual swing angle measured by the dual-axis tilt sensor 21 remains within a very small range. When the motion concludes and the trolley and slewing mechanism come to rest, the load reaches a stable state almost instantly, as the sway energy has been largely offset during the motion.

[0036] The specific operating parameters and basic settings are as follows: Known conditions: Load attributes: 40-foot standard container (weight ≈ 30 tons, within the crane's rated load range); Motion parameters: lifting height L = 25m, maximum length of wire rope L0 = 30m, amplitude: from r = 15m to r = 35m, average radial velocity v r =1.0m / s, amplitude variation time t=(35-15) / 1=20s.

[0037] Rotation: from 0° to 30° (converted to 0.5236 rad), average angular velocity ω = 0.25 rad / s, rotation time t = 0.5236 / 0.25 = 2.09 s (based on the total amplitude change time of 20 s, subsequent processing is uniform rotation) 3. Core parameters: k1= ,k2= , k3=0.25; control parameter k p =0.9, k i =0.08s -1 、k d =0.2s. It should be noted that k in this scheme p =0.9, k i =0.08s -1 、k d =0.2s, the optimal solution for the QTZ80 tower crane determined after more than 20 on-site commissionings, meets the control objectives of "swing angle suppression rate ≥ 90%, convergence time ≤ 12s, and no oscillation", and can be adapted to other equipment using the same method.

[0038] Substituting the above parameters into formulas (1) to (6) for calculation, we finally get u=-1, which is converted into specific operating actions as follows: Rotary motor: voltage is reduced by 10% (from the rated 380V to 342V) to reduce the rotation acceleration; variable amplitude motor: current is reduced by 8% (from the rated 50A to 46A) to slow down the radial speed; execution effect: the swing angle increase is controlled from the predicted 1.32rad to the actual 0.8rad (suppression rate is about 40%).

[0039] Comparative Example The operation task is the same as that in Example 1, and the same crane is used to perform exactly the same operation task, but the monitoring and control system of the present invention is completely disabled. The control is entirely performed by a skilled operator with more than five years of experience. The operator, relying on his rich experience, tried to suppress the swing through pre-operation and smooth start and stop. However, at the moment when the rotation and amplitude change are started at the same time, the huge combined inertia force still caused the container to swing significantly. During the movement, after observing the swing, the operator tried to offset it through reverse operation, but due to the delay in human reaction and the execution delay of the crane itself, the correction operation often lagged behind the phase of the swing, sometimes even resulting in more violent oscillations. When the crane moved above the target position and stopped, the container was still performing a large and continuous pendulum motion. The operator had to spend extra time waiting for it to decay naturally to an acceptable range, or perform multiple small-scale jog operations to forcibly stop the swing.

[0040] Data comparison In order to more accurately evaluate the superiority of the technical solution of the present invention, the key performance indicators of the above embodiment and the comparative example were recorded and compared, and the results are shown in the following table: The comparative data in the table above clearly demonstrates that the implementation of this invention's technical solution reduces load sway during high-speed, compound crane movements by nearly 90%. More crucially, load stabilization time is dramatically reduced from over 18 seconds to less than 2 seconds, significantly reducing idle waiting time during the operation cycle and improving the efficiency of a single operation by over 27%. This has significant economic value and practical significance for modern ports and logistics terminals striving for high efficiency.

[0041] In summary, the crane load monitoring system and method for sway suppression of the present invention effectively resolves the control delay and incomplete suppression issues present in the prior art, achieving full, efficient, and proactive suppression of crane load sway. Those skilled in the art should understand that the foregoing description is merely a preferred embodiment of the present invention and does not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

[0042] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A crane load monitoring system for suppressing sway, characterized in that: The system comprises: a perception module (10) for collecting in real time kinematic parameters, dynamic parameters and posture parameters of the suspended load during the operation of the crane; A coupling model calculation module (11) is connected to the data of the perception module (10) and collects real-time parameters based on the perception module (10), and prospectively calculates the load prediction swing angle induced by the active motion of the crane through a preset rigid body dynamics model; A feedforward control module (12) is data-connected to the coupling model calculation module (11), and is used to receive the predicted swing angle and generate active, compensatory feedforward control instructions in advance based on the predicted swing angle; A feedback correction module (13) is data-connected to the perception module (10) and is used to receive the real-time attitude parameters of the payload collected by the perception module (10), and generate feedback correction instructions for eliminating model errors and external disturbances based on the deviation between the real-time attitude parameters and a preset target attitude; and an execution adaptation module (14) which is control-connected to the feedforward control module (12) and the feedback correction module (13) and is used to synthesize the feedforward control instruction and the feedback correction instruction to form a total control instruction, and convert the total control instruction into a physical signal that can be recognized and executed by the original control system of the crane, so as to perform superimposed correction on the original operation instruction.

2. The system according to claim 1, wherein: The sensing module (10) comprises a dual-axis tilt sensor (21) provided on the load hanger or hook assembly for real-time measurement of the actual swing angle θ of the load in two orthogonal directions, tangential and radial. meas ; A rotary encoder (22) is provided on the slewing mechanism of the crane and is used to measure the slewing angle position of the crane in real time and to parse out the slewing angular velocity ω and the slewing angular acceleration α based on the slewing angle position; A variable amplitude travel encoder (23) is provided on the variable amplitude mechanism of the crane and is used to measure the radial displacement of the crane trolley or boom in real time to determine the variable amplitude r, and to calculate the radial speed v of the variable amplitude mechanism accordingly. r ; A lifting stroke encoder (24) is provided on the lifting mechanism of the crane and is used to measure the pay-out length of the wire rope in real time to determine the effective length L of the current wire rope; and a current sensor (25) connected in series to a power supply circuit of a motor driving the lifting mechanism or the luffing mechanism for real-time monitoring of the working current of the driving motor, so as to indirectly measure the acceleration a of the load in the lifting or luffing direction.

3. The system according to claim 2, characterized in that The dual-axis inclination sensor (21) is a capacitive accelerometer sensor based on micro-electromechanical system technology, whose measurement range is set to ±15 degrees, and has an internal temperature compensation circuit and a Kalman filter algorithm for filtering high-frequency noise; the rotary encoder (22) is an absolute value multi-turn photoelectric rotary encoder; the variable amplitude stroke encoder (23) and the lifting stroke encoder (24) are both wire-type linear displacement sensors.

4. The system according to claim 1, wherein: The coupling model calculation module (11), the feedforward control module (12) and the feedback correction module (13) are integrated into an embedded controller (30) with a microcontroller unit as the core. The microcontroller unit is based on an ARM Cortex-M7 core and has a built-in floating-point operation unit.

5. The system according to claim 1, wherein: The coupling model calculation module (11) includes a centrifugal force-Coriolis force coupling swing angle calculation submodule (111) and an inertial force swing angle calculation submodule (112). The centrifugal force-Coriolis force coupling swing angle calculation submodule (111) is used to calculate a first predicted swing angle θ1(t) in a tangential plane by using formula (1) when the crane performs a rotation and amplitude variable compound motion: in, and are respectively the sensing module (10) at the integration time The measured slewing angular velocity, slewing angular acceleration, amplitude change and radial velocity, k1 and k2 are pre-calibrated dimensionless correction coefficients, and the inertial force swing angle calculation submodule (112) is used to calculate the second predicted swing angle θ2 (t) in the motion direction when the crane performs translational acceleration and deceleration motion by formula (2): in, for The acceleration of the lifting / luffing mechanism at any moment, g is the acceleration due to gravity, g=9.8m / s 2 , L is the current effective length of the wire rope, L0 is the maximum working length of the wire rope, and k3 is the pre-calibrated length correction coefficient.

6. The system according to claim 5, characterized in that The feedforward control module (12) comprises a rotary operation compensation amount generating submodule (121) and an acceleration / deceleration operation compensation amount generating submodule (122). The rotary operation compensation amount generating submodule (121) is used by the rotary feedforward submodule to generate a rotary operation compensation amount based on formula (3): in, ∈[0.8,1.2] is the proportional coefficient, Prediction based on the centrifugal force-Coriolis force coupling submodule Always swing the corner, To perform a delay, =100ms; The compensation amount generating submodule (122) is used to generate the acceleration / deceleration operation compensation amount based on formula (4): in, ∈[0.05,0.1]s -1 is the integration coefficient, Prediction based on the inertial force swing submodule Always swing the corner.

7. The system according to claim 6, characterized in that The feedback correction module (13) is used to calculate the feedback control amount based on formula (5): Among them, k d ∈[0.1,0.3]s is the differential coefficient, is the error between the measured swing angle and the target swing angle, is the measured swing angle collected by the dual-axis tilt sensor, is the target swing angle, is the error change rate, which is the difference between the two errors divided by the sampling time.

8. The system according to claim 7, characterized in that The execution adaptation module (14) is used to calculate the total control amount based on formula (6) and output: Among them, sat() is the saturation function, u min 、u max They are the minimum and maximum control quantities allowed by the actuator respectively.

9. A crane load monitoring method for suppressing sway, characterized in that: The following steps are involved: S1: Collect the crane's rotation angular velocity ω and angular acceleration through the perception module (10) , amplitude r, radial speed v of the amplitude mechanism r , lifting height L, acceleration a in the lifting or luffing direction and load swing angle θ; S2: Based on the parameters collected in step S1, the coupled model calculation module is used to substitute into formula (1) and formula (2) to calculate the predicted swing angles θ1(t) and θ2(t); S3: Substitute θ1(t) obtained in step S2 into formula (3) to generate the rotation operation compensation u1, and substitute θ2(t) into formula (4) to generate the acceleration / deceleration operation compensation u2; S4: Based on the load swing angle θ collected in step S1 and the target swing angle θ ref = 0, substitute the error e into formula (5) to generate the feedback control quantity u f ; S5: u1, u2 obtained in step S3 and u obtained in step S4 f Substitute into formula (6) to calculate the total control quantity u, which is output to the original control system of the crane through the execution adaptation module.

10. The method according to claim 9, wherein It also includes parameter calibration steps: S01: Control the crane to rotate at a known, constant angular velocity ω, without lifting or amplitude change, and maintain a fixed amplitude change amplitude r for a certain time T. Record the maximum value of the stable tangential swing angle θ1 measured by the dual-axis inclination sensor, and substitute it into k1=θ1 / (ω 2 rT) calculate k1; S02: Under the condition of no lifting and no amplitude variation, start from rest and rotate uniformly with a known, constant angular acceleration α, and maintain a fixed amplitude variation r. After the uniform acceleration rotation continues for a certain time T, record the maximum value of the stable tangential swing angle θ2 measured by the dual-axis inclination sensor and substitute it into Calculated ; S03: Control the crane to lift or lower at a known, constant acceleration a for a certain time T without rotation or amplitude change. During this process, record the maximum working length L0 of the wire rope and the current wire rope length L, and use the dual-axis inclination sensor to measure the maximum value of the stable swing angle θ3, and substitute it into Calculate k3.

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