Digital control method for multi-machine cooperative hoisting of flat arm type tower crane

Abstract

The invention discloses a digital control method for multi-machine cooperative hoisting of flat arm type tower cranes, which synchronously controls rotation and amplitude variation of two tower cranes and trolley movement through a computer control system, optimizes a cooperative path and balances a load. The method specifically comprises the steps that a kinematics model is established, a kinematics equation is established according to the position relation between a tower crane and a component, and a related equation of the rotation angular speed of a large arm and the movement speed of a trolley is established; trajectory optimization control: fitting a trajectory by adopting a cubic polynomial, and iteratively solving an optimal control equation in combination with the hoisting performance parameters of the tower crane; real-time monitoring and closed-loop correction: calculating the eccentric amplitude of the lifting hook and the load rate of the tower crane by acquiring theoretical coordinates of the lifting hook, and correcting when the eccentric amplitude and the load rate exceed the range; and after the component reaches a designated position, in-place posture adjustment is achieved. According to the invention, full-process digital control of multi-machine collaborative operation can be realized, the hoisting synchronization precision, the load balance and the construction safety are obviously improved, the manual intervention is reduced, and the method is suitable for hoisting heavy components of super high-rise buildings.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and more specifically to a digital control method for multi-machine collaborative hoisting of a flat-arm tower crane. Background Technology

[0002] In building construction, especially in the construction of super high-rise structures, ordinary lifting machinery is insufficient to reach the corresponding lifting height. Lifting operations and vertical material transportation during construction typically rely on tower cranes, whose transportation efficiency limits the overall construction progress. Limited by the lifting capacity of tower cranes, heavy components can only be lifted in sections, which increases on-site workload and extends the overall construction period; furthermore, the quality of high-altitude operations is difficult to guarantee. For conventional lifting machinery, a dual-crane lifting operation can be chosen to increase the single-lift capacity and improve on-site construction efficiency. Tower cranes rely on the rotation of their booms to transfer objects; under manual control, it is difficult to coordinate two tower cranes to achieve the dual-crane lifting effect. Problems with synchronization can lead to serious consequences such as tower crane collisions and collapses. Summary of the Invention

[0003] This invention provides a digital control method for multi-crane collaborative lifting using a flat-arm tower crane. The method achieves high-precision dual-crane lifting by synchronously controlling the rotation of two tower cranes and the movement of the trolley through a computer control system, and realizes closed-loop control through monitoring the coordinates of monitoring points. This method can improve the efficiency of tower crane lifting during construction, reduce the overall construction period, and improve construction quality.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a digital control method for multi-crane collaborative lifting of a flat-arm tower crane. The components to be lifted are connected at both ends to tower cranes A and B respectively via flexible connections, allowing free rotation at the connection points. At least two measurement points are arranged on the components to be lifted. The three-dimensional coordinates of the measurement points are acquired by a monitoring system. The slewing and luffing movements of the two flat-arm tower cranes are synchronously controlled by a computer control system to optimize the operating path, balance the load rates of the two tower cranes, and achieve closed-loop control by monitoring the coordinates of the two monitoring points. This ensures that the hook eccentricity and load rate of the two tower cranes are within allowable ranges during the luffing process. Specifically, the method includes the following steps:

[0005] S1: Establish a calculation model based on the positional relationship between the tower crane and the component, and construct the kinematic equations of the tower crane hook and the position of the component;

[0006] Angle θ between the two tower crane booms i(i＝A、B) With the position S of the car i(i＝A、B) Relationship satisfies:

[0007]

[0008] Where L ABL is the distance between the slewing centers of the two tower cranes, and L is the horizontal distance between the two lifting points of the hoisting component.

[0009] The rotational angular velocity ω of the two tower crane booms i(i＝A、B) With the speed v of the car i(i＝A、B) Relationship satisfies:

[0010]

[0011] in ω represents the current position matrix of the tower crane hook, Q represents the current position matrix of the component, and ω represents the spin velocity of the component.

[0012] S2: According to the expression, the system has three degrees of freedom. θ is selected. A θ B S A As a control variable, a cubic polynomial is used to fit the trajectory to establish θ. A (t), θ B (t), S A (t) The governing equations use the initial position of the tower crane hook, the target position, and the velocity as initial parameters;

[0013] S3: α is the tower crane load rate during hoisting, defining the load balance index between the two tower cranes. Tower crane luffing speed ω i (t)<ω max v i (t)<v max and acceleration performance Tower crane lifting performance boom length S A (t)<S Amax Using constraints as conditions, the solution is obtained by iteratively optimizing minΛ using an intelligent algorithm, thus yielding θ. A (t), θ B (t), S A (t) Governing equations;

[0014] S4: Solve the trajectory of tower crane B in reverse by using S1 based on the obtained control equations.

[0015] Furthermore, after the component reaches the designated position, its positioning posture is adjusted. The posture adjustment method is as follows: Keep one tower crane hook stationary while simultaneously controlling the boom extension and retraction of the other tower crane hook. The relationship between the component's adjustment angle β relative to the horizontal plane and the tower crane position satisfies:

[0016]

[0017] Tower crane hook retraction speed κ=Lω k cosβ, tower crane luffing speed ω i(i＝A、B) With v i(i＝A、B) satisfy:

[0018]

[0019] Where ω k Adjust the speed of component attitude.

[0020] Furthermore, each tower crane contains a first sensor and a second sensor, wherein the first sensor is arranged on the tower crane boom and can obtain the current boom angle θ. i(i＝A、B) The second sensor is mounted on the vehicle and can obtain the vehicle's current position S. i(i＝A、B) The data is then fed back to the computer control system.

[0021] Furthermore, during the hoisting process, the synchronicity of the tower crane, i.e., the eccentricity of the hook, is monitored, and an alarm is issued if the value exceeds the warning threshold. The tower crane synchronicity monitoring method involves reading the current operating information of the tower crane system or obtaining the current boom angle θ from the first and second sensors. i(i＝A、B) And the car's current position S i(i＝A、B) Obtain the theoretical coordinates K' of the hook i(i＝A、B) The coordinates of the measured point E on the component i(i＝1,2) The actual coordinates K of the hook are calculated by using the coordinate transformation matrix M. i(i＝A、B) So, the eccentricity of the hook When γ > 1°, an early warning is triggered and the speed is corrected.

[0022] Furthermore, the tower crane load rate is monitored during the hoisting process. The tower crane load rate monitoring method is as follows: the current working radius is obtained by reading the current operating information of the tower crane system or obtaining the current trolley position from the second sensor, and the rated lifting capacity G at the current position is obtained by interpolation according to the lifting performance table. Si The theoretically shared reaction force of each lifting point is calculated based on the ratio of the distance between the lifting point and the center of gravity. An early warning is triggered when α > 80%.

[0023] Furthermore, it also includes displaying key information such as tower crane load rate, hook eccentricity, and current operating parameters on the control terminal to help staff understand the current working status.

[0024] A digital control method for multi-crane collaborative hoisting of a flat-arm tower crane, the on-site operation process is as follows: 1) Control the two tower cranes to change their luffing height to connect with the components to be hoisted respectively, arrange two easily observable measuring points on the surface of the components and measure the initial coordinates of the hook and the measuring points to obtain the coordinate transformation matrix M between the hoisting point and the measuring points;

[0025] 2) The operator inputs the tower crane position information, initial coordinates of the component lifting point, target coordinates of the component, tower crane performance table, component weight, and other basic information into the control program.

[0026] 3) The program iteratively optimizes the hoisting path with the goal of balancing the loads of the two tower cranes, obtains the time history control curves of the two tower cranes, and generates the tower crane load curves during the hoisting process.

[0027] 4) Control the tower crane hook to lift synchronously to complete the lifting process. After the load stabilizes, lift the hook to a certain height again to ensure that there is no collision on the path during the lifting process. The height should not be too high to avoid generating large horizontal forces due to asynchronous lifting.

[0028] 5) The program controls the tower crane to start synchronous hoisting according to the time history control curve. During the hoisting process, the hook is raised and lowered synchronously to keep the horizontal angle of the component unchanged. The program displays information such as load rate, control speed, and hoisting progress on the screen. During the hoisting process, the tower crane synchronization is controlled by comparing the coordinates of the measured points on the component with the theoretical coordinates.

[0029] 6) After hoisting to the position, begin attitude adjustment. The program controls one tower crane to remain stationary while the other tower crane simultaneously raises and lowers its hook and adjusts its luffing to complete the attitude adjustment of the component. This process can also be carried out after step 4, which involves removing the mold.

[0030] 7) The hooks of the two tower cranes are lowered simultaneously to place the component in the designated position and fix it in place.

[0031] 8) Disconnect the tower crane from the component, and return the tower crane to its initial position to begin the next lifting operation.

[0032] In summary, the hoisting control method of the present invention can realize automatic synchronous control and process monitoring of multi-machine collaborative hoisting of flat-arm tower cranes, significantly improving hoisting synchronization accuracy, load balance and construction safety, increasing the single hoisting efficiency of tower cranes during construction, shortening the overall construction period, reducing the use of other large machinery, reducing engineering construction costs, and reducing manual intervention. It is suitable for hoisting heavy components of super high-rise buildings. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the hoisting operation.

[0034] Figure 2 A simplified geometric diagram;

[0035] Figure 3 This is a schematic diagram showing the location of monitoring points on the component to be hoisted.

[0036] Figure 4 This is the overall flowchart. Detailed Implementation

[0037] The following is in conjunction with the appendix Figures 1 to 4 The present invention provides a more detailed description of the specific implementation of a digital control method for multi-machine collaborative hoisting of a flat-arm tower crane.

[0038] A digital control method for multi-crane collaborative hoisting of a flat-arm tower crane is disclosed. This method achieves dual-crane lifting by coordinating the control of two tower cranes, including tower crane A 101, tower crane B 102, a computer control system 103, a monitoring system 104, and the component to be hoisted 105. Tower crane A 101 and tower crane B 102 are arranged at different heights, with tower crane A 101 being higher than tower crane B 102. In the following description, a plane coordinate system is established using the rotation center of tower crane A as the origin and the line connecting the rotation centers of tower crane A and tower crane B as the x-axis.

[0039] The computer control system can communicate with tower crane A 101 and tower crane B 102 via wired or wireless means and control them to perform corresponding actions. It can receive the coordinates of monitoring points measured by the monitoring system 104. The two ends of the component 105 to be hoisted are connected to tower crane A and tower crane B respectively via flexible connections (steel wire ropes, etc.), and can rotate freely at the connection points. The monitoring system 104 can obtain the coordinates of the monitoring points on the component 105 in the plane coordinate system 111 and transmit them to the computer monitoring system 104.

[0040] Each tower crane contains a first sensor and a second sensor. The first sensor is located on the tower crane's jib and can obtain the current angle θ of the jib. i(i＝A、B) The second sensor is mounted on the vehicle and can obtain the vehicle's current position S. i(i＝A、B) .

[0041] A digital control method for dual-crane lifting using a flat-arm tower crane includes coordinated control of the luffing speed of the two tower cranes, optimization of the operating path, and balancing of the load rates of the two tower cranes. This ensures that the hook eccentricity and load rate of the two tower cranes are within allowable ranges during the luffing process, eliminating the need for manual operation during the lifting process. The coordinated control and load balancing steps are as follows:

[0042] S1: Establish a calculation model based on the positional relationship between the tower crane and the component, and construct the kinematic equations of the tower crane hook and the position of the component;

[0043] Angle θ between the two tower crane booms i(i＝A、B) With the position S of the car i(i＝A、B) Relationship satisfies:

[0044]

[0045] Where L AB L is the distance between the slewing centers of the two tower cranes, and L is the horizontal distance between the two lifting points of the lifting component.

[0046] The rotational angular velocity ω of the two tower crane booms i(i＝A、B) With the speed v of the car i(i＝A、B) Relationship satisfies:

[0047]

[0048] in ω represents the current position matrix of the tower crane hook, Q represents the current position matrix of the component, and ω represents the spin velocity of the component.

[0049] S2: According to the expression, the system has three degrees of freedom. θ is selected. A θ B S A As a control variable, a cubic polynomial is used to fit the trajectory to establish θ. A (t), θ B (t), S A (t) The governing equations use the initial position of the tower crane hook, the target position, and the velocity as initial parameters;

[0050]

[0051] S3: α is the tower crane load rate during hoisting, defining the load balance index between the two tower cranes. Tower crane luffing speed ω i (t)<ω max v i (t)<v max and acceleration performance Tower crane lifting performance boom length S A (t)<S Amax Using constraints such as θ, the minΛ is iteratively optimized using optimization algorithms such as particle swarm optimization to obtain θ. A (t), θ B (t), S A (t) Governing equations;

[0052]

[0053] S4: Solve the motion trajectory of tower crane 102 in reverse by using S1 based on the obtained control equations.

[0054] Preferably, in this embodiment, the initial angle of the component remains constant during the component hoisting process; when the boom of the luffing tower crane undergoes pitching and luffing movements, the hook moves synchronously; during synchronous hoisting, the component remains horizontal or at its initial angle constant through the synchronous lifting and lowering of the hook. The hook compensates for the lifting distance during the hoisting process. Hook retraction speed

[0055] In this preferred embodiment, the component's positioning posture is adjusted after it reaches the designated position. The posture adjustment method involves keeping one tower crane hook stationary while simultaneously controlling the boom extension and retraction of the other tower crane's hook. The relationship between the component's adjustment angle β relative to the horizontal plane and the tower crane's position satisfies:

[0056]

[0057] Tower crane hook retraction speed κ=Lω k cosβ, tower crane luffing speed ω i(i =A、 B) With v i(i =A、 B) satisfy:

[0058]

[0059] Where ω k Adjust the speed of component attitude.

[0060] In this preferred embodiment, the synchronicity (hook eccentricity) and load rate of the tower crane are monitored synchronously during the hoisting process, and an alarm is issued when the warning value is exceeded. The tower crane synchronicity monitoring method involves reading the current operating information of the tower crane system or obtaining the current boom angle θ from the first and second sensors. i(i＝A、B) And the car's current position S i(i＝A、B) Obtain the theoretical coordinates K' of the hook i(i＝A、B) The coordinates of the measured point E on the component i(i＝1,2) The actual coordinates K of the hook are calculated by using the coordinate transformation matrix M. i(i＝A、B) So, the eccentricity of the hook When γ > 1°, an early warning is triggered and the speed is corrected.

[0061] Tower crane load rate monitoring method: The current operating radius is obtained by reading the current operating information of the tower crane system or acquiring the current trolley position from the second sensor. The rated lifting capacity G at the current position is obtained by interpolation according to the lifting performance table. Si Calculate the theoretically shared reaction force at each lifting point based on the ratio of the distance between the lifting point and the center of gravity:

[0062]

[0063] In the formula l i Let G be the distance from the lifting point to the center of gravity, and G be the total weight of the component. Then the tower crane load rate is... An alert is triggered when α > 80%.

[0064] A digital control method for dual-machine lifting of a flat-arm tower crane also includes displaying key information such as tower crane load rate, hook eccentricity, and comparison of current operating parameters with theoretical parameters on a display terminal (computer screen) to help staff understand the current working status.

[0065] This invention provides a digital control method for dual-machine lifting of a flat-arm tower crane, and the on-site operation process is as follows:

[0066] 1) Control the luffing of two tower cranes to connect with the lifting points respectively to the components to be lifted. Arrange two easily observable measuring points on the surface of the components and measure the initial coordinates of the hook and the measuring points to obtain the coordinate transformation matrix M between the lifting points and the measuring points;

[0067] 2) The operator inputs the tower crane position information, initial coordinates of the component lifting point, target coordinates of the component, tower crane performance table, component weight and other basic information into the control program;

[0068] 3) The program iteratively optimizes the hoisting path with the goal of balancing the loads of the two tower cranes, obtains the time history control curves of the two tower cranes, and generates the tower crane load curves during the hoisting process;

[0069] 4) Control the tower crane hook to lift synchronously to complete the removal of the tire. After the load stabilizes, lift the hook to a certain height again to ensure that there is no collision on the path during the lifting process. The height should not be too high to avoid generating large horizontal forces due to asynchronous lifting.

[0070] 5) The program controls the tower crane to start synchronous hoisting according to the time history control curve, and displays information such as load rate, control speed, and hoisting progress on the screen. During the hoisting process, the program controls the synchronization of the tower crane by comparing the coordinates of the measured points on the components with the theoretical coordinates.

[0071] 6) After the hoisting is in place, the attitude adjustment begins. The program controls one tower crane to remain stationary while the other tower crane simultaneously raises and lowers the hook and changes the luffing to complete the attitude adjustment of the component. This process can also be carried out after step 4 is completed.

[0072] 7) The hooks of the two tower cranes are lowered simultaneously to place the component in the designated position and secure it.

[0073] 8) Disconnect the tower crane from the component, and return the tower crane to its initial position to begin the next lifting operation.

[0074] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A digital control method for multi-crane collaborative hoisting of a flat-arm tower crane, characterized in that: The component to be hoisted is connected to tower cranes A and B respectively via flexible connections at both ends, allowing free rotation at the connection points. At least two measurement points are arranged on the component. The three-dimensional coordinates of these measurement points are acquired by a monitoring system. A computer control system synchronously controls the luffing and trolley movement of the two flat-arm tower cranes, optimizing the operating path, balancing the load rates of the two tower cranes, and achieving closed-loop control by monitoring the coordinates of the two monitoring points. This ensures that the hook eccentricity and load rate of the two tower cranes remain within allowable ranges during the luffing process. The specific steps include: S1: Establish a calculation model based on the positional relationship between the tower crane and the component, and construct the kinematic equations of the tower crane hook and the position of the component; Angle θ between the two tower crane booms i(i＝A , B) With the position S of the car i(i＝A , B) Relationship satisfies: Where L AB L is the distance between the slewing centers of the two tower cranes, and L is the horizontal distance between the two lifting points of the lifting component. The rotational angular velocity ω of the two tower crane booms i(i＝A , B) With the speed v of the car i(i＝A , B) Relationship satisfies: in ω represents the current position matrix of the tower crane hook, Q represents the current position matrix of the component, and ω represents the spin velocity of the component. S2: with θ A θ B S A As a control variable, a cubic polynomial is used to fit the trajectory, establishing θ. A (t), θ B (t), S A (t) The governing equations use the initial position of the tower crane hook, the target position, and the velocity as initial parameters; S3: α is the tower crane load factor, defined as the load balance index during the hoisting process of two tower cranes. Tower crane luffing speed ω i (t)<ω max v i (t)<v max and acceleration performance Tower crane lifting performance boom length S A (t)<S Amax etc. are used as limiting constraints. The objective function Λ is minimized through iterative optimization to obtain θ. A (t), θ B (t), S A (t) Governing equations; S4: Solve the motion trajectory of tower crane B through S1 based on the obtained control equations.

2. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 1, characterized in that: During the hoisting process, after the component reaches the designated position, the positioning posture of the component is adjusted. The posture adjustment method is to keep the position of one tower crane hook stationary while controlling the raising and lowering of the hook of the other tower crane boom as it changes amplitude.

3. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 2, characterized in that: The relationship between the component's adjustment angle β relative to the horizontal plane and the tower crane's position satisfies: Tower crane hook retraction speed κ=Lω k cosβ, tower crane luffing speed ω i(i＝A , B) With v i(i＝A , B) satisfy: Where ω k Adjust the speed of component attitude.

4. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 1, characterized in that: Each tower crane contains a first sensor and a second sensor. The first sensor is located on the tower crane's jib and can obtain the current angle θ of the jib. i(i＝A , B) The second sensor is mounted on the vehicle and can obtain the vehicle's current position S. i(i＝A , B) The data is then fed back to the computer control system.

5. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 4, characterized in that: During the hoisting process, the synchronicity of the tower crane, i.e., the eccentricity of the hook, is monitored, and an alarm is issued when the value exceeds the warning threshold. The tower crane synchronicity monitoring method involves reading the current operating information of the tower crane system or obtaining the current boom angle θ from the first and second sensors. i(i＝A , B) And the car's current position S i(i＝A , B) Obtain the theoretical coordinates K' of the hook i(i＝A B ) The coordinates of the measured point E on the component i(i＝1,2) The actual coordinates K of the hook are calculated by using the coordinate transformation matrix M. i(i＝A B), then the hook eccentricity amplitude When γ > 1°, an early warning is triggered and the speed is corrected.

6. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 4, characterized in that: During the hoisting process, the tower crane load rate is monitored. The tower crane load rate monitoring method is to obtain the current working radius by reading the current operating information of the tower crane system or obtaining the current trolley position from the second sensor, and then interpolate the rated lifting capacity G at the current position according to the lifting performance table. Si The theoretical reaction force shared by each lifting point is calculated based on the ratio of the distance between the lifting point and the center of gravity. An early warning is triggered when α > 80%.

7. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 1, characterized in that: It also includes displaying key information such as tower crane load rate, hook eccentricity, and current operating parameters on the control terminal to help staff understand the current working status.

8. The digital control method for multi-machine collaborative hoisting of a flat-arm tower crane according to claim 1, characterized in that, The on-site operation procedure is as follows: 1) Control the luffing of two tower cranes to connect with the lifting points respectively to the components to be lifted. Arrange two easily observable measuring points on the surface of the components and measure the initial coordinates of the hook and the measuring points to obtain the coordinate transformation matrix M between the lifting points and the measuring points; 2) The operator inputs the tower crane position information, initial coordinates of the component lifting point, target coordinates of the component, tower crane performance table, and basic information on component weight into the control program; 3) The program iteratively optimizes the hoisting path with the goal of balancing the loads of the two tower cranes, obtains the time history control curves of the two tower cranes, and generates the tower crane load curves during the hoisting process; 4) Control the tower crane hook to lift synchronously to complete the removal of the tire. After the load stabilizes, lift the hook to a certain height again to ensure that there is no collision on the path during the lifting process. The height should not be too high to avoid generating large horizontal forces due to asynchronous lifting. 5) The program controls the tower crane to start synchronous hoisting according to the time history control curve, and displays information such as load rate, control speed, and hoisting progress on the screen. During the hoisting process, the program controls the synchronization of the tower crane by comparing the coordinates of the measured points on the components with the theoretical coordinates. 6) After hoisting to the correct position, begin attitude adjustment. The program controls one tower crane to remain stationary while the other tower crane simultaneously raises and lowers its hook and adjusts its luffing to complete the attitude adjustment of the component. This process can also be performed after step 4, where the frame is removed from the mold. 7) The hooks of the two tower cranes are lowered simultaneously to place the component in the designated position and secure it. 8) Disconnect the tower crane from the component, and return the tower crane to its initial position to begin the next lifting operation.

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