Anti-swing control method for tower crane
Through actual measurement and model prediction of the swing of the tower crane, the Lagrangian equation is used to establish a physical and mechanical model and actively control it, which solves the problem of tower crane load swing, realizes efficient and precise anti-swing control, and improves the tower crane The operating accuracy and construction efficiency reduce costs and safety risks.
Patent Information
- Application Number
- CN202411248401.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-01-07
AI Technical Summary
The tower crane has load swing during operation, which affects the efficiency and safety of lifting operations. The existing mechanical anti-swing cost is high, and the electrical anti-swing control accuracy and efficiency are low.
Through actual measurement of tower crane data, a gear model is established, a physical and mechanical model is established based on the Lagrangian equation, and the swing direction and swing amplitude of the hook are predicted, and the active control signal is input when the hook swings to the maximum amplitude and rotates in the direction that is about to swing. The main arm or the moving variable amplitude car is controlled to prevent swing and stabilizing hooks.
It realizes efficient and accurate load swing control, reduces manual operation errors and reaction time, reduces shutdowns and losses during construction, improves the operating accuracy and operating efficiency of tower cranes, and significantly reduces operation and maintenance costs.
Smart Images
Figure CN119263088A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of tower crane construction, and in particular to an anti-sway control method for a tower crane. Background Art
[0002] With the continuous expansion of the scale and increase in complexity of modern construction projects, tower cranes are increasingly used in construction. Tower cranes have the advantages of large lifting capacity, wide operating range, and flexible operation. They have become important equipment in the construction of high-rise buildings, large bridges and other large infrastructure. However, during the operation of tower cranes, the existence of load swing greatly affects the efficiency and safety of lifting operations. Therefore, how to effectively control and reduce the load swing of tower cranes has become one of the problems that need to be solved in the field of construction machinery.
[0003] Traditional anti-sway control methods mainly rely on the operator's experience and skills. However, due to the limitations of human reaction speed and accuracy, traditional methods are difficult to meet the needs of efficient and accurate anti-sway. With the development of control theory and computer technology, automatic anti-sway control methods based on control algorithms have gradually become a research hotspot. Modern anti-sway control systems mainly include mechanical anti-sway and electrical anti-sway.
[0004] Mechanical anti-sway systems usually reduce sway through structural optimization design, but this method has problems such as high cost and limited scope of application. Electrical anti-sway systems use sensors, actuators and control algorithms to achieve load sway control, but the control accuracy and efficiency of electrical anti-sway are low, and the construction progress and safety are still greatly affected, resulting in potential economic losses and risks.
[0005] Therefore, it is necessary to provide a tower crane anti-sway control method that can solve the problems of high mechanical anti-sway cost and low electrical anti-sway control accuracy and control efficiency of tower cranes in the prior art. Summary of the invention
[0006] The object of the present invention is to provide a tower crane anti-sway control method, which can solve the problems of high mechanical anti-sway cost and low electrical anti-sway control accuracy and control efficiency of tower crane in the prior art.
[0007] The present invention is achieved in that:
[0008] A tower crane anti-sway control method comprises the following steps:
[0009] Step 1: Measure the tower crane data and establish the gear model;
[0010] Step 2: Establish the physical mechanics model of the tower crane based on the Lagrange equation;
[0011] Step 3: According to the actual gear operation of the tower crane, predict the swing direction and swing amplitude of the hook when the tower crane rotates and the luffing trolley stops moving;
[0012] Step 4: Based on the swing direction and swing amplitude of the hook after the tower crane stops moving, the swing of the hook is actively controlled through the anti-swing hook stabilization control strategy.
[0013] The step 1 comprises the following sub-steps:
[0014] Step 1.1: The movement of the tower crane slewing and luffing trolley in each gear position can be divided into three stages: acceleration start t1~t2, uniform speed movement t2~t3 and deceleration stop t3~t4. Among them, the speed v in uniform speed movement is the maximum speed during the movement process;
[0015] Step 1.2: During the acceleration start phase t1-t2, and the deceleration stop phase t3-t4, the speeds are respectively expressed by equations (1) and (2);
[0016]
[0017] Step 1.3: During the acceleration start-up phase t1-t2, the displacement s of the tower crane slewing and luffing trolley is expressed by equation (3);
[0018]
[0019] Step 1.4: During the uniform motion stage t2-t3, the displacement s of the tower crane slewing and luffing trolley is expressed by equation (4);
[0020]
[0021] Step 1.5: During the deceleration and stopping stage t3-t4, the displacement s of the tower crane slewing and luffing trolley is expressed by equation (5);
[0022]
[0023] Step 1.6: Obtain the acceleration function through the first-order derivative of the velocity function with respect to time, expressed by equation (6);
[0024]
[0025] The tower crane motion data monitored by the sensor is calibrated to obtain the maximum speed v of the tower crane's rotation motion and the luffing trolley motion in each gear and the time t1, t2, t3, and t4 of each stage, thereby obtaining the gear model.
[0026] The step 2 comprises the following sub-steps:
[0027] Step 2.1: Establish a spatial coordinate system with the top of the tower crane column as the origin. The Z axis of the spatial coordinate system is vertical, the X axis of the spatial coordinate system is along the length direction of the initial position of the boom, and the Y direction of the spatial coordinate system is perpendicular to the X axis and the Z axis;
[0028] Step 2.2: The tower crane rotation angle w and the load mass m hung on the hook can be measured by the sensor, and the length L of the wire rope hanging the load is known; the displacement U of the luffing trolley along the boom, the speed and acceleration of the luffing trolley can be determined by the gear model, i.e., equations (1) to (6);
[0029] Step 2.3: Use the Lagrange equation to establish the physical and mechanical model of the tower crane load swing system, and solve the swing angle θ and acceleration α of the hook, which can be expressed by equations (7) and (8);
[0030]
[0031] Among them, angle θ is the angle between the wire rope and the vertical direction, and angle α is the angle between the projection of the boom and the wire rope on the horizontal plane where the load is located;
[0032] Step 2.4: Based on the initial motion conditions of the hook and equations (7) and (8), predict the motion of the hook after the tower crane stops moving.
[0033] In step 4, the anti-sway hook stabilization control strategy is: at the moment when the hook swings to the maximum amplitude but has not yet swung back, an active control signal is input to rotate the tower crane boom or move the luffing trolley along the direction in which the hook is about to swing.
[0034] The active control signals of the anti-sway hook control strategy include: the input amplitude of the active control, the start time of the active control and the period of the active control.
[0035] The direction of the active control is consistent with the displacement direction of the hook to be swung, and the input amplitude of the active control should be equal to the amplitude of the hook to be swung predicted in step 3.
[0036] The period of active control in each direction is
[0037] Compared with the prior art, the present invention has the following beneficial effects:
[0038] The present invention collects and analyzes real-time data of the tower crane, predicts the swing of the hook and generates accurate active control signals, drives the boom or the luffing trolley to actively control the hook to prevent it from swinging and stabilize it with the active control input amplitude, active control time and active control period, provides an efficient and reliable anti-swing solution for tower cranes, effectively suppresses the swing of the load, reduces the safety hazards caused by the load swing, not only greatly reduces the error and reaction time of manual operation, but also significantly reduces the shutdown and loss caused by unexpected swing during the construction process, as well as the cost of operation and maintenance, thereby improving the operating accuracy and working efficiency of the tower crane, as well as the construction efficiency and economic benefits of the overall project. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 It is a flow chart of the anti-sway control method of a tower crane of the present invention;
[0040] Figure 2 It is a schematic diagram of model symbols of step 2 in the anti-sway control method of a tower crane of the present invention;
[0041] Figure 3 It is a schematic diagram of the active control input amplitude in the anti-sway control method of a tower crane of the present invention;
[0042] Figure 4 It is a schematic diagram of the simulation of the swing of the tower crane hook before and after the anti-sway control method of the tower crane of the present invention is applied.
[0043] In the figure, 1 is a boom and 2 is a column. DETAILED DESCRIPTION
[0044] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0045] Please see attached Figure 1 , a tower crane anti-sway control method, comprising the following steps:
[0046] Step 1: Measure the tower crane data and establish the gear model.
[0047] Specifically, the motion trajectory, motion speed and motion acceleration of the tower crane's slewing and luffing trolley in each gear are monitored in real time by sensors, and a mathematical model is established based on the real-time monitoring data to describe the gear of the tower crane.
[0048] The sensors on the tower crane are used to obtain the rotation angle of the tower crane, the movement speed and acceleration of the tower crane and the luffing trolley.
[0049] The step 1 comprises the following sub-steps:
[0050] Step 1.1: The movement of the tower crane slewing and luffing trolley in each gear can be divided into three stages: acceleration start t1~t2, uniform speed movement t2~t3 and deceleration stop t3~t4. Among them, the speed v in uniform speed movement is the maximum speed during the movement.
[0051] Step 1.2: During the acceleration start phase t1-t2, and the deceleration stop phase t3-t4, the speeds can be expressed by equation (1) and equation (2) respectively.
[0052]
[0053] Step 1.3: During the acceleration start-up phase t1-t2, the displacement s of the tower crane slewing and luffing trolley can be expressed by equation (3).
[0054]
[0055] Step 1.4: During the uniform motion stage t2-t3, the displacement s of the tower crane rotation and the luffing trolley can be expressed by equation (4).
[0056]
[0057] Step 1.5: During the deceleration and stopping stage t3-t4, the displacement s of the tower crane slewing and luffing trolley can be expressed by equation (5).
[0058]
[0059] Step 1.6: The acceleration function can be obtained by taking the first-order derivative of the velocity function with respect to time, which is expressed by equation (6).
[0060]
[0061] The tower crane motion data monitored by the sensor can be calibrated to obtain the maximum speed v of the tower crane's rotation motion and the luffing trolley motion in each gear and the time t1, t2, t3, and t4 of each stage, thereby obtaining the gear model.
[0062] Step 2: Establish the physical mechanical model of the tower crane based on the Lagrange equation.
[0063] Please see attached Figure 2 , the step 2 comprises the following sub-steps:
[0064] Step 2.1: Establish a spatial coordinate system with the top of the tower crane column 2 as the origin. The Z axis of the spatial coordinate system is vertical, the X axis of the spatial coordinate system is along the length direction of the initial position of the boom 1, and the Y direction of the spatial coordinate system is perpendicular to the X axis and the Z axis.
[0065] Step 2.2: The tower crane rotation angle w (i.e., the rotation angle of the boom 1 relative to the X-axis) and the load mass m hung on the hook can be measured by the sensor, and the length L of the wire rope hanging the load is known; the displacement U of the luffing trolley along the boom 1 (i.e., the sum of the displacements of the luffing trolley during startup acceleration, uniform motion, and deceleration), the speed and acceleration of the luffing trolley can be determined by the gear model, i.e., equations (1) to (6).
[0066] The mass m of the load and the swing angle w of the boom 1 are obtained by using the sensors on the tower crane. The length L of the wire rope for suspending the load is known before construction. Based on the known data and equations (1) to (6), a physical and mechanical model of the acceleration of the swing angle θ and α of the hook can be established.
[0067] Step 2.3: Use the Lagrange equation to establish the physical and mechanical model of the tower crane load swing system, and solve the swing angle θ and acceleration α of the hook, which can be expressed by equations (7) and (8).
[0068]
[0069] Step 2.4: Based on the initial motion conditions of the hook and equations (7) and (8) (i.e., the physical and mechanical model of the hook's swing angle θ and the acceleration α), predict the motion of the hook (including the swing direction and swing amplitude of the hook) after the tower crane stops moving (i.e., the boom 1 stops rotating and the boom trolley stops moving).
[0070] Specifically, based on the initial movement conditions of the hook, including the initial movement speed, angle and angular velocity of the hook, the swing angles θ and α of the hook after the tower crane stops moving can be calculated by combining equations (7) and (8).
[0071] Among them, angle θ is the angle between the wire rope and the vertical direction, and angle α is the angle between the projection of the boom 1 and the wire rope on the horizontal plane where the load is located. According to angles θ and α, the direction and amplitude of the hook's upcoming swing can be predicted, so as to facilitate the subsequent active control of the hook according to its swing state.
[0072] Step 3: According to the actual gear operation of the tower crane, predict the swing direction and amplitude of the hook when the tower crane rotates and the luffing trolley stops moving.
[0073] By calculating the angles θ and α based on the spatial coordinate system and the actual gear movement of the tower crane, the direction and amplitude of the hook's upcoming swing can be determined, and the peak and trough positions of the swing in each direction can be determined based on the swing amplitude.
[0074] Step 4: Based on the swing direction and swing amplitude of the hook after the tower crane stops moving, the swing of the hook is actively controlled through the anti-swing hook stabilization control strategy.
[0075] The anti-sway hook stabilization control strategy is: at the moment when the hook swings to the maximum amplitude but has not swung back, an active control signal is input to rotate the tower crane boom 1 or move the luffing trolley along the direction in which the hook is about to swing.
[0076] At the moment when the hook swings back, an additional motion gear is actively input to provide a reverse force for the hook's swing back process, thereby achieving the purpose of stabilizing the hook.
[0077] The active control signal of the anti-sway hook stabilization control strategy includes: the input amplitude of active control, the start time of active control and the period of active control. Before the hook starts to swing, according to the predicted swing law, active control is performed at the peak point of the hook swing. The direction of active control is consistent with the displacement direction of the hook to be swung. The input amplitude of active control should be equal to or close to the amplitude of the hook to be swung predicted in step 3. The active control period in each direction is
[0078] Please see attached Figure 3 The quasi-sine wave curve in the figure is the swing amplitude of the hook, and the step curve is the input amplitude of the active control. Figure 3 It can be seen that during the swing of the hook, after four to five active controls, the swing amplitude of the hook can be decayed to 0 in a relatively short time, thereby achieving the purpose of preventing the hook from swinging and stabilizing it.
[0079] Please see attached Figure 4 The dotted line in the figure shows the free attenuation swing amplitude history of the hook after active control of the present invention, and the solid line shows the free attenuation swing amplitude history of the hook without control. Figure 4 It can be seen that the swing amplitude of the uncontrolled hook is larger after the tower crane stops moving, and the free decay is slower, while the swing amplitude of the hook actively controlled by the present invention is smaller after the tower crane stops moving, and the swing can be stopped as soon as possible at a smaller swing amplitude, thereby achieving the purpose of stabilizing the hook and improving the operating safety of the tower crane.
[0080] From the perspective of economic benefits, the present invention has the following advantages:
[0081] 1) Improve construction efficiency: By reducing the hook swing time and controlling the downtime during operation, the present invention can significantly shorten the construction period and save manpower and equipment costs.
[0082] 2) Reduce safety risks: effectively control load swing, reduce the risk of equipment damage and casualties caused by swing, and reduce insurance costs and possible compensation costs.
[0083] 3) Save maintenance costs: Due to the reduction of load swing, the wear and tear of tower cranes and related equipment is greatly reduced, which extends the service life of the equipment and thus reduces maintenance and replacement costs.
[0084] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the invention. Therefore, 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 tower crane anti-sway control method, characterized in that: The following steps are involved: Step 1: Measure the tower crane data and establish the gear model; Step 2: Establish the physical mechanics model of the tower crane based on the Lagrange equation; Step 3: According to the actual gear operation of the tower crane, predict the swing direction and swing amplitude of the hook when the tower crane rotates and the luffing trolley stops moving; Step 4: Based on the swing direction and swing amplitude of the hook after the tower crane stops moving, the swing of the hook is actively controlled through the anti-swing hook stabilization control strategy.
2. The tower crane anti-sway control method according to claim 1 is characterized in that: The step 1 comprises the following sub-steps: Step 1.1: The movement of the tower crane slewing and luffing trolley in each gear position can be divided into three stages: acceleration start t1~t2, uniform speed movement t2~t3 and deceleration stop t3~t4. Among them, the speed v in uniform speed movement is the maximum speed during the movement process; Step 1.2: During the acceleration start phase t1-t2, and the deceleration stop phase t3-t4, the speeds are respectively expressed by equations (1) and (2); Step 1.3: During the acceleration start-up phase t1-t2, the displacement s of the tower crane slewing and luffing trolley is expressed by equation (3); Step 1.4: During the uniform motion stage t2-t3, the displacement s of the tower crane slewing and luffing trolley is expressed by equation (4); Step 1.5: During the deceleration and stopping stage t3-t4, the displacement s of the tower crane slewing and luffing trolley is expressed by equation (5); Step 1.6: Obtain the acceleration function through the first-order derivative of the velocity function with respect to time, expressed by equation (6); The tower crane motion data monitored by the sensor is calibrated to obtain the maximum speed v of the tower crane's rotation motion and the luffing trolley motion in each gear and the time t1, t2, t3, and t4 of each stage, thereby obtaining the gear model.
3. The tower crane anti-sway control method according to claim 1 is characterized in that: The step 2 comprises the following sub-steps: Step 2.1: Establish a spatial coordinate system with the top of the tower crane column (2) as the origin, the Z axis of the spatial coordinate system is vertical, the X axis of the spatial coordinate system is along the length direction of the initial position of the boom (1), and the Y direction of the spatial coordinate system is perpendicular to the X axis and the Z axis; Step 2.2: The tower crane rotation angle w and the load mass m hung on the hook can be measured by the sensor, and the length L of the wire rope hanging the load is known; the displacement U of the luffing trolley moving along the boom (1), the speed and acceleration of the luffing trolley can be determined by the gear model, i.e., equations (1) to (6); Step 2.3: Use the Lagrange equation to establish the physical and mechanical model of the tower crane load swing system, and solve the swing angle θ and acceleration α of the hook, which can be expressed by equations (7) and (8); Wherein, angle θ is the angle between the steel wire rope and the vertical direction, and angle α is the angle between the projection of the boom (1) and the steel wire rope on the horizontal plane where the load is located; Step 2.4: Based on the initial motion conditions of the hook and equations (7) and (8), predict the motion of the hook after the tower crane stops moving.
4. The tower crane anti-sway control method according to claim 1 is characterized in that: In step 4, the anti-sway hook stabilization control strategy is: at the moment when the hook swings to the maximum amplitude but has not yet swung back, an active control signal is input to rotate the tower crane boom (1) or move the luffing trolley along the direction in which the hook is about to swing.
5. The tower crane anti-sway control method according to claim 4 is characterized in that: The active control signals of the anti-sway hook control strategy include: the input amplitude of the active control, the start time of the active control and the period of the active control.
6. The tower crane anti-sway control method according to claim 5 is characterized in that: The direction of the active control is consistent with the displacement direction of the hook to be swung, and the input amplitude of the active control should be equal to the amplitude of the hook to be swung predicted in step 3.
7. The tower crane anti-sway control method according to claim 5 is characterized in that: The period of active control in each direction is